CHAPTER Anesthesia for Pediatric ENT Surgerytchanesthesia.org/uploads/3/1/9/5/3195694/29... · way management during tonsillectomy.Advantages and disadvantages of LMA use during tonsillectomy

CHAPTER Anesthesia for PediatricENT SurgeryRONALD S. LITMAN, D.O.

DANIEL S. SAMADI, M.D.

JOSEPH D. TOBIAS, M.D.29

Ear Surgeries

Myringotomy and Tube Placement

Tympanomastoidectomy

Tympanoplasty

Nasal Surgery

Nasal Cautery

Nasal Fracture Reduction

Juvenile Angiofibroma Resection

Upper Airway Surgery

Tonsillectomy

Peritonsillar Abscess Incision and Drainage

Bleeding Tonsil

Adenoidectomy

Esophageal Foreign Body

Frenulectomy

Dental and Oral Surgical Procedures

Laryngeal Surgery

Laryngoscopy and Bronchoscopy

Suspension Laryngoscopy

Tracheostomy

Lower Airway Surgery

Bronchial Foreign Body

Neck Surgery

Thyroglossal Duct Cyst

Branchial Cleft Cyst

Neck Mass Biopsy and Excision

Cystic Hygroma

Ear, nose, and throat (ENT) surgery represents a largeproportion of pediatric surgeries and remains one of themost challenging because of the frequency of airwayobstruction in infants and small children.The anesthesi-ologist must be familiar with a variety of airway manage-ment techniques that are unique for each type ofprocedure, as well as the different types of airway instru-ments used by otolaryngologists.

This chapter reviews the anesthetic implications forthe most common ENT procedures performed in children.

ENT emergencies that manifest as life-threatening airwayobstruction are extensively reviewed in Chapter 18.

EAR SURGERIES

Myringotomy and Tube Placement

Otitis media is a bacterial infection that develops withina transudate in the middle ear in susceptible children. Itis usually caused by chronic eustachian tube obstructionfrom either congenital narrowing or adenoidal hypertro-phy. Myringotomy and tube placement consists of theinsertion of tiny ventilating tubes through the tympanicmembrane to drain fluid from the middle ear and preventfuture fluid collections. It is the most common surgicalprocedure requiring general anesthesia in children, whofrequently present with fever and upper respiratorytract infections that will not abate until the ear fluid isdrained.The major focus of the preoperative assessmentis to ensure that the child does not have any lower airwaysymptoms that indicate acute reactive airway disease orpneumonia.

The standard anesthesia technique for myringotomyand tube placement consists of an inhalational induction,usually with sevoflurane and N2O, although halothane isstill used in many centers. Once the child has reacheda depth of unconsciousness sufficient to preventresponse to a painful stimulus, the anesthesiologist turnsthe child’s head to the side while maintaining mask anes-thesia, and the tubes are placed by the surgeon usinga microscope (Fig. 29-1). Intravenous access is usuallynot necessary. Each ear tube insertion typically lasts nomore than 5 minutes. Many children will manifest upperairway obstruction when the head is turned. This usuallyabates with application of continuous positive airwaypressure (CPAP) or placement of an oral airway.Laryngospasm may occur if the depth of anesthesia isinsufficient for the procedure. Central or obstructive

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apnea may occur and is treated with positive-pressureventilation.

Postoperative pain is severe in some children immedi-ately after the procedure and can occasionally last a fewhours. Thus prophylactic analgesia is indicated. Choicesinclude oral or rectal acetaminophen 40 mg/kg, ibuprofen10 mg/kg,codeine 0.5–1 mg/kg,or oxycodone 0.1 mg/kg.Intranasal or intramuscular fentanyl 1–2 µg/kg, adminis-tered while the child is anesthetized, provides adequatepostoperative analgesia and decreases agitation duringemergence from general anesthesia without prolongingdischarge times. Similar results are attained usingintranasal butorphanol 25 µg/kg. Postoperatively, childrenwith preexisting upper respiratory tract infections maydevelop hypoxemia and require oxygen therapy.

Tympanomastoidectomy

Indications for a tympanomastoidectomy includechronic otitis media or presence of a cholesteatoma.The surgery is performed through an incision behind theear to expose the ear canal and tympanic membrane, orthrough the ear canal. The ear canal is widened and aportion of the mastoid bone is removed.The eardrum isrebuilt and the cholesteatoma is removed if present.These children are usually otherwise healthy, but mayhave hearing loss. The procedure is performed in thesupine position with the child’s head turned away fromthe side of the surgery. The OR table is turned 90–180degrees away from the anesthesia machine. Therefore,the anesthesiologist must anticipate the requirement of abreathing circuit with sufficient length. During the pro-cedure, the head and neck are completely covered withdrapes, so access to the airway is difficult. There is mini-mal blood loss or third-space fluid losses. If the surgeonrequests facial nerve monitoring, and paralysis is desiredfor endotracheal intubation, an intermediate-acting neu-romuscular blocker should be chosen and used for intu-bation only.The use of N2O should be discussed with thesurgeon who may request that it be discontinued priorto placement of a tympanic graft. A temporary urinarycatheter should be considered for procedures greaterthan 4 hours duration. Hyperthermia is possible if awarming blanket is used. The main postoperative con-cern is nausea and vomiting, so antiemetic prophylaxisshould be administered. Postoperatively, children may bedischarged home if they are well hydrated and do nothave severe pain.

Tympanoplasty

A tympanoplasty is repair of a perforated ear drumusing a temporalis fascia graft. It may also involve recon-struction of the bones of the middle ear.A postauricularapproach is most often used. Virtually all anesthetic

implications and techniques are the same as those fortympanomastoidectomy.

NASAL SURGERY

Nasal Cautery

Nasal cautery is performed in children who havechronic nose bleeds secondary to friable blood vesselsalong the anterior portion of the nasal septum. Thechildren are usually healthy. The procedure consists ofbrief electrocauterization and typically lasts no more than10–15 minutes. Some anesthesiologists may choose toprovide mask anesthesia while intermittently removingthe mask for the surgeon to cauterize the vessels.Laryngealmask airway (LMA) or endotracheal tube placement arereasonable options, especially if the child is expected tobleed into the back of the pharynx. Postoperative anal-gesia is minimal and easily treated without opioids.

Nasal Fracture Reduction

Nasal fractures occur commonly in children followingfacial trauma. Reduction and fixation is rarely a surgicalemergency. The children are scheduled for elective closedor open reduction as an outpatient. Closed reductionconsists of the manipulation of the nasal bones exter-nally with the assistance of instruments through thenasal openings.Bleeding is typical, though not enough tobe clinically important. However, there is a significantamount of blood that enters the nasopharynx. For thisreason,most pediatric anesthesiologists will choose LMAplacement or endotracheal intubation for airway man-agement, and will thoroughly suction the pharynx priorto removal. Postoperative pain may require opioid anal-gesia.Since postoperative nausea and vomiting is common,a prophylactic antiemetic is indicated.

Juvenile Angiofibroma Resection

A juvenile angiofibroma is a benign vascular tumor ofthe posterior nasopharynx that can spread into contigu-ous structures. Adolescent boys are most often affectedand present with chronic nasal obstruction or painlessnasal bleeding that is not associated with trauma. Manypatients will undergo preoperative embolization to limitintraoperative bleeding,which may be severe. Additionalpreoperative assessment includes a complete bloodcount, coagulation studies, and a type-and-crossmatch.Induction and maintenance of anesthesia are routine.Once consciousness is lost, two large-bore intravenouscatheters are inserted for volume replacement and pos-sible blood transfusion. An arterial line is often placed,depending on the size of the tumor and extent of theprocedure.Airway management consists of a straight or

2 PEDIATRIC ANESTHESIA: THE REQUISITES IN ANESTHESIOLOGY


RAE oral endotracheal tube, depending on the surgicalapproach. A temporary urinary catheter should beplaced if the anticipated duration of the surgery is morethan 3–4 hours.The surgical approach is dependent onthe size and exact location and spread of the tumor. Themain intraoperative concern is blood loss. At the endof the procedure the nasal cavity is frequently packed.Depending on the extent of the surgical resection thesechildren may remain intubated at the end of the proce-dure and mechanically ventilated in the ICU until theirvital signs and fluid status have stabilized.

UPPER AIRWAY SURGERY

Tonsillectomy

Tonsillectomy remains a common childhood surgicalprocedure. There are two indications:recurrent infection(usually in children older than 4 years) and sleep apnea(usually in children under 4 years).When performed forchildren with sleep apnea, adenoidectomy is usuallyperformed at the same time. Anesthetic implications ofchildren with sleep apnea are discussed in Chapter 4.

Most routine tonsillectomies are performed as outpa-tient surgery. Certain groups of children with a high riskof postoperative upper airway obstruction should bescheduled for overnight hospital admission. Thisincludes children less than 4 years of age and those withsevere sleep apnea. In addition, children with coexistingmedical problems (e.g., trisomy 21, obesity, bleedingdisorders) should be hospitalized postoperatively.

Some surgeons require preoperative hemoglobin test-ing and coagulation studies, even though there is littlesupport in the literature for this practice, unless there isa history of a bleeding disorder in the child or the family.Nonsteroidal anti-inflammatory drugs (NSAIDs) shouldbe discontinued at least days prior to surgery. A preoper-ative oral anxiolytic should be administered at a decreaseddose in young children with significant airway obstruc-tion. Oral acetaminophen 15 mg/kg may be added to thepremedication to help decrease postoperative pain.

The goals of anesthetic management for tonsillectomyare a motionless patient during the procedure, a rapidand smooth emergence, postoperative pain relief, andcontrol of postoperative nausea and vomiting. Followinginduction of anesthesia, an oral RAE endotracheal tube isinserted to accommodate the mouth opening deviceused by the surgeon. There are several types of thesedevices;each is designed to secure the endotracheal tubeagainst the tongue in the midline, and allow maximalsurgical exposure of the pharynx.A growing number ofpediatric anesthesiologists routinely use an LMA for air-way management during tonsillectomy. Advantages anddisadvantages of LMA use during tonsillectomy are listedin Box 29-1.Adjuvant medications include an opioid for

pain and a 5-HT3 antagonist to help prevent postopera-tive nausea and vomiting. Dexamethasone also decreasesthe incidence of postoperative nausea and vomiting, isassociated with improved postoperative fluid intake, andlessens the severity of postoperative pain.Neuromuscularblockers are administered by some anesthesiologists.Maintenance of anesthesia can consist of a combinationof an inhalational agent, N2O, or continuous infusion ofpropofol. Propofol maintenance is associated with lesspostoperative nausea and vomiting.

Once the anesthesiologist has taped the endotrachealtube or LMA appropriately,the OR table is turned through90 degrees.A rolled-up sheet or similar “shoulder roll” isplaced underneath the shoulders of the patient, and thehead is placed in extension. When the surgeon insertsthe mouth gag, the child’s mouth is maximally opened(Fig.29-2).During this process the endotracheal tube maybe pulled out of the trachea or critically compressed.Therefore, the anesthesiologist should ensure that venti-latory parameters remain the same as before the gag wasplaced. In addition, because of the surgeon’s viewpointfrom above the head of the child, he or she may notnotice that certain portions of the lips and tongue havebecome pinched by the gag. The anesthesiologist mustcarefully observe this process to ensure that injury doesnot occur.

During tonsillectomy, there are several anestheticconcerns. Blood loss varies and may be significant, but isdifficult to measure. However, it is rarely severe enoughto warrant transfusion. Fluids should consist of an iso-tonic solution to replace the preoperative deficit, bloodloss, and minimal insensible losses. Some surgeons preferto infiltrate the tonsillar fossae with a local anesthetic todecrease postoperative pain. Others, however, feel thatthis practice results in a higher incidence of postopera-tive bleeding. At the end of the procedure, the surgeonmay pass a soft catheter to suction gastric contents.However, blood is rarely recovered, and there is noevidence that this practice influences the incidence ofpostoperative nausea and vomiting. Once the surgeonhas completed the procedure the table is turned back tothe anesthesiologist and an oral airway or bite block isinserted into the mouth to prevent the child from bitingdown and compressing the endotracheal tube duringemergence. The nasal passages are gently suctioned forsecretions and excess blood but the catheter should gono farther than the anterior nasal cavity to avoid dislodg-ing a fresh clot from the adenoid bed in the nasopharynx.Similarly, oral suctioning should be gentle and limited tothe anterior midline of the oral cavity so that the tonsil-lar fossae are avoided.Bright red blood that is continuallysuctioned during emergence should prompt a reexplo-ration before the child is awakened.

There are two schools of thought with regard to thesafest and most appropriate method for emergence and

Anesthesia for Pediatric ENT Surgery 3


tracheal extubation following tonsillectomy: wide-awakeversus deep extubation.The major advantage of a wide-awake extubation is the patient’s conscious ability tomaintain airway patency immediately following the pro-cedure. The main purported disadvantage is an increasedtendency for bleeding secondary to coughing and buck-ing during emergence, which may disrupt clots at thesurgical site. The main advantage of a deep extubationis the avoidance of bleeding during emergence, andthe facilitation of throughput in a busy surgical suite.Disadvantages include possible respiratory depressionand failure to maintain airway patency,and laryngospasmduring the semiconscious phase of emergence as a resultof secretions or blood in the larynx.

Following an awake tracheal extubation, the child iscarefully observed for several minutes to ensure airwaypatency and the ability to maintain spontaneous ventila-tion without hypoxemia. The child should be kept in theoperating room until he or she demonstrates the abilityto maintain a patent airway without jaw thrust or chinlift. Occasionally, an oral airway may be left in place dur-ing transportion to the intensive care unit. The classic“tonsil position” with the child lying on one side andwith the head lower than the body will facilitate upperairway patency and draining of blood and secretionsfrom the mouth.This may be the case for the relativelyunconscious child. In practice, however, this is rarely uti-lized since the supine position is preferred for airwaymanagement during transport.

At The Children’s Hospital of Philadelphia,a wide-awakeextubation technique is preferred. Coughing duringemergence is minimized by administering a moderatedose of intraoperative morphine (0.075–0.15 mg/kg) andlow concentrations of inhalational agent.Neuromuscularblockade is usually administered. Box 29-2 describes ourstandard anesthetic protocol. Using this technique, bleed-ing during emergence and postoperative laryngospasmare exceedingly rare.

Other centers, however, are equally adamant aboutefficacy and safety of the deep extubation technique.This technique requires a relatively greater use of inhala-tional agent and less opioid, to facilitate adequate airwaypatency following tracheal extubation. Local anestheticinfiltration is also recommended. If deep extubation isroutinely used, the institution must develop a culturewithin the postoperative recovery site that facilitatesexpedient treatment of transient airway obstruction andlaryngospasm.

The most important postoperative concern followingtonsillectomy is upper airway obstruction. The precisecause is unknown and may be related to airway edema,residual effects of general anesthesia,or a combination ofthe two. It occurs more often in children less than 3 yearsof age,and in children with preexisting sleep apnea.It mostoften manifests within the first postoperative 30 minutes.

Delayed upper airway obstruction is uncommon. Initialtreatment consists of optimal positioning of the headand neck in a position that is most consistent with air-way patency, cool mist in oxygen, and administration ofsteroids if not already given. If these measures fail torelieve continuing hypoxemia (SpO2 < 90%), placementof a soft lubricated nasopharyngeal airway is indicated.Most children with distress secondary to upper airwayobstruction will allow placement of this device withoutmuch of a struggle. Should this measure be necessary,the child should be admitted to a postoperative hospitalunit with close nursing supervision (e.g., PICU). Shouldthe child remain hypoxemic despite placement of anasopharyngeal airway, tracheal intubation is then indi-cated, with a trial of extubation at a later time.

The most common postoperative concerns followingtonsillectomy are pain relief and postoperative nauseaand vomiting. Opioids should be titrated to achieve suf-ficient analgesia while avoiding respiratory depressionand upper airway obstruction.Many children will alternatebetween crying in pain and falling asleep and becominghypoxemic. This is a continual challenge for the anes-thesiologist and intensive care staff. Outpatients withmoderate pain may be given oxycodone or equivalentanalgesic syrup prior to leaving the facility. NSAIDS arenot administered to tonsillectomy patients for 2 weeksbecause of the increased incidence of postoperativebleeding.

Nausea and vomiting occur in up to 75% of childrenfollowing tonsillectomy. They are likely caused byresidual swallowed blood that irritates the lining of thestomach, or other unknown factors related to the site ofthe surgery or the anesthetic technique (e.g., opioids).Vomiting can result in exacerbation of bleeding from thetonsillectomy site, and dehydration. Treatment includesmaintenance of intravenous fluid therapy, antiemetics,and continuous observation for hypovolemia and anemia.Continued presence of blood in the vomitus should ini-tiate examination for a primary bleed. Additional dosesof a 5-HT3 antagonist may be administered, but are gen-erally less effective for treating nausea alone.Droperidol isoften effective, especially for nausea. However, at thetime of this writing it is no longer used by most centersbecause of the “black box warning” concerning its asso-ciation with a prolonged Q-T interval. Metoclopramide isusually ineffective in this setting. Most centers willemploy one of a number of other antiemetics for refrac-tory vomiting. Children with ongoing postoperative nau-sea and vomiting should have their intravenous accessmaintained to provide continuous hydration. If vomitingis continuous and severe, hospital admission is war-ranted for continuation of intravenous hydration andantiemetic therapy. The vast majority of children will nolonger manifest postoperative nausea and vomiting bythe second postoperative day.



Additional postoperative complaints following tonsil-lectomy include otalgia, fever, uvular swelling, andvelopharyngeal insufficiency.

Peritonsillar Abscess Incision and Drainage

A peritonsillar abscess results when bacterial tonsillitisspreads to the tonsillar fossae and soft palate. It producesfever, severe sore throat, dysphagia, and trismus frompterygoid muscle spasm.Patients may be dehydrated fromthe fever and the inability to drink. Preoperative consid-erations include administration of antibiotics, intravenousisotonic fluids, and a MRI or CT scan of the neck to esti-mate the spread of the infection and severity of airwayobstruction. Airway evaluation is often difficult due to thepresence of trismus.Preoperative sedatives are avoided ifairway obstruction is evident.

Induction of anesthesia will depend on the likelihoodof a difficult intubation. If the anesthesiologist suspects apotential difficult ventilation or intubation, spontaneousventilation should be maintained during induction ofanesthesia until it is known that positive-pressure venti-lation is successful. If a difficult airway is not suspected,a rapid sequence induction and tracheal intubation areindicated. The trismus will abate upon administration ofgeneral anesthesia.The anesthesiologist must be preparedfor rupture of the abscess during direct laryngoscopy,and be prepared with a double-suction set-up, varioussized styletted, cuffed, oral RAE endotracheal tubes, andan extra working laryngoscope.Visualization of the glot-tic opening may be difficult secondary to altered pharyn-geal anatomy. The intraoperative anesthetic implicationsare the same as for a tonsillectomy.Tracheal extubationshould take place when the child is fully awake to opti-mize upper airway patency. However, postextubationairway obstruction may occur from residual pharyngealswelling.

Bleeding Tonsil

Bleeding following tonsillectomy can be severe andlife-threatening. Primary bleeding occurs in the first24 hours and is a direct result of residual operative bleed-ing.Secondary bleeding occurs 5–10 days postoperativelyas a result of scab dislodgement.These cases are usuallyconsidered surgical emergencies. It is difficult to estimatethe blood actually lost. Most is swallowed, and some chil-dren will vomit this swallowed blood but estimates ofits volume are inaccurate. Therefore, anesthesiologistsshould assume hypovolemia and anemia until provenotherwise.The preoperative history should focus on theduration of the vomiting, and presence of any indicatorsof hypovolemia or anemia, such as dizziness or fainting.Physical exam should focus on detection of hypovolemiaor anemia by checking skin turgor, signs of dehydration,

and presence of pallor. Preoperatively, IV access isobtained,and blood samples are sent for a CBC and coag-ulation studies. An additional blood sample should beretained for possible type-and-cross if the hemoglobinlevel is low. Aggressive fluid hydration with an isotonicsolution is geared toward normalization of vital signs andadequate urine output. Children often remain normoten-sive despite hypovolemia and anemia. Unless the bleed-ing is active and brisk, normalization of fluid status is thegoal prior to surgery. The anesthesiologist should reviewan available anesthetic record from the original surgeryto determine the presence of problems or issues thatwould influence the subsequent anesthetic technique(e.g., difficult ventilation or intubation). Small doses ofintravenous midazolam may be administered shortly beforesurgery under the direct supervision of the anesthesiol-ogist.Some anesthesiologists may wish to administer intra-venous metoclopramide (0.1 mg/kg) to facilitate gastricemptying. The OR should be prepared with a double-suction set-up, several different sized styletted, cuffed,oral RAE endotracheal tubes, and an extra workinglaryngoscope.

Rapid sequence induction of anesthesia and trachealintubation is indicated using sodium pentothal or propo-fol, and succinylcholine or rocuronium. If hypovolemia issuspected, lesser doses of these hypnotic agents shouldbe used to avoid hypotension upon induction of generalanesthesia.Alternatively they can be combined with ket-amine, or ketamine can be used alone. Occasionally theanesthesiologist will encounter a situation wherebythe pharynx is filled with blood, thereby impeding ade-quate visualization of the laryngeal inlet. Simultaneoushypotension secondary to systemic vasodilation in a childwith preexisting hypovolemia may occur. These are tensemoments – the ENT surgeon should be present in the ORduring induction, and the most qualified anesthesiologistavailable should be managing the airway.Once the airwayis secured by tracheal intubation, the stomach canbe suctioned. Intraoperative anesthetic considerationsare the same as for a routine tonsil with the exception ofmore vigilant attention to blood loss and fluid replace-ment. Tracheal extubation should occur with the childfully awake because of the possibility of residual blood inthe stomach. Postoperative concerns are the same asafter routine tonsillectomy and include pain and emesis.

Adenoidectomy

Adenoidectomy is primarily indicated in young childrenwith chronic nasal obstruction, chronic sinusitis, andmiddle ear infections caused by eustachian tube block-age. Upper respiratory illnesses are extremely common,and often do not abate until after the surgery has beenperformed. Perioperative anesthetic considerations areessentially the same as for tonsillectomy, except for a



lesser amount of postoperative pain, and less chance forpostoperative upper airway obstruction. Morphine isoften limited to 0.05 mg/kg intraoperatively, and thentitrated to achieve analgesia in the intensive care unit.

Esophageal Foreign body

In the course of placing objects in their mouths,toddlers will occasionally swallow these objects, whichmay become stuck in the esophagus. Most commonly, acoin becomes lodged in the proximal esophagus and mustthen be removed under general anesthesia with endotra-cheal intubation. Severe pain or airway obstruction arethe only reasons this procedure becomes an emergency.Otherwise,the child should be admitted,made nil-by-mouth(NPO), and intravenous access obtained with admini-stration of maintenance fluids. A radiograph should beobtained just prior to surgery to confirm that the coinhas not already passed into the stomach. In the preoper-ative holding area, intravenous midazolam may be titratedto effect. Induction and maintenance of anesthesia isroutine, with the expectation that this procedure willlast no more than 5–10 minutes. If the anesthesiologistsuspects a residual full stomach, then rapid sequenceinduction and tracheal intubation are indicated. Cricoidpressure may or may not be applied, depending on thelocation of the foreign body. The OR table is turned90 degrees away from the anesthesiologist and the sur-geon uses a rigid esophagoscope to remove the coin.Postoperative pain is usually mild and does not ordinarilyrequire opioids.

Frenulectomy

A frenulectomy is an elective procedure that entailscutting the frenulum, which is the midline structurebelow the tongue. It is indicated for ankyloglossia, a con-dition of restricted tongue movement due to congenitalovergrowth of the frenulum. It may be performed by adissection technique and sutures,or using electrocautery,or both. Children are usually healthy. Airway manage-ment varies depending on the preference of the surgeonand anesthesiologist. Spontaneous ventilation via maskanesthesia or nasopharyngeal airway is easily accom-plished if the surgeon is amenable. Others will feel morecomfortable with placement of an LMA or endotrachealtube, because of the possibility of bleeding into the backof the pharynx. Postoperative pain is mild to moderateand responds to small doses of opioids and/or ketorolac.

Dental and Oral Surgical Procedures

The most common dental procedures requiringgeneral anesthesia in children consist of extractions andrestorations of teeth. Children are often scheduled forthis procedure with general anesthesia because of a

previous failure to cooperate using sedative techniques.Another reason to use general anesthesia is when mildsedation is untenable because of the presence of devel-opmental delay or other behavioral problem. Many chil-dren have preexisting comorbidities. These should becompletely investigated prior to the day of the procedure.Premedication with an anxiolytic is usually indicated.Uncooperative adolescents with developmental delaymay refuse oral premedication and require intramuscularadministration of ketamine (see Chapter 12).

An inhalational induction of general anesthesia isusually performed. Neuromuscular blockade is optional.After the child loses consciousness,a head wrap is snuglyapplied to the head to use as a secure attachment for theendotracheal tube (Fig. 29-3). A nasotracheal intubationis performed using a nasal RAE tube, aided by a Magillforceps. The OR table may be turned 90 degrees awayfrom the anesthesiologist. All connections of the breath-ing circuit must be checked and appropriately tightenedprior to beginning the procedure.Fluid requirements areminimal.Hyperthermia is possible during long procedures.Unintentional breathing circuit disconnections or obstruc-tions of the capnograph line are possible hazards. Thedentist or oral surgeon will usually infiltrate a moderateamount of local anesthesia. Administration of acetamino-phen and/or ketorolac may help alleviate postoperativeresidual soreness. Small doses of an opioid may also berequired.

LARYNGEAL SURGERY

Laryngoscopy and Bronchoscopy

Direct laryngoscopy and flexible or rigid bronchoscopyare used as part of a diagnostic work-up in the evaluationof respiratory compromise (e.g., laryngomalacia, subglot-tic stenosis), as a therapeutic tool for the treatment oflaryngeal lesions (e.g.,papilloma,cysts),and for the removalof foreign bodies from the upper or lower airways.

A variety of medical conditions may cause airway abnor-malities that require diagnostic or therapeutic intervention.As an example, children born prematurely are especiallyprone to develop subglottic stenosis, and are frequentlyevaluated for chronic stridor, or inability to be success-fully weaned from mechanical ventilation.The one com-mon theme among children presenting for laryngoscopyand bronchoscopy is an obstructed upper or lower air-way that may worsen with the loss of pharyngeal muscletone that accompanies induction of general anesthesia,or present difficulty with endotracheal intubation.

The preoperative history should consist of a thoroughreview of previous anesthetics and optimization of comor-bid conditions.Physical exam is focused on upper airwayanatomy and the severity of existing airway obstruction.In the case of potentially significant airway obstruction,



the history and physical exam will determine the anestheticapproach to securing the airway (see Chapter 18).Thereare no specific requirements for preoperative laboratorytesting.Radiographic studies of the head and neck regionshould be reviewed to assess the potential for airwayobstruction during induction of general anesthesia.

Preoperative anxiolysis is tailored to the age andmedical condition of the patient. Sedative medicationsmay exacerbate existing airway obstruction and leadto life-threatening hypoxemia. Intravenous atropine orglycopyrrolate is frequently administered to dry airwaysecretions, to prevent vagal-induced bradycardia, and toattenuate cholinergic-mediated bronchoconstriction dur-ing airway manipulation.All appropriate equipment andpersonnel for dealing with a potentially difficult airway,including surgical equipment for tracheostomy, shouldbe available. Preoperative communication with the sur-geon will facilitate a precise understanding of the proce-dural components and will enable the anesthesiologistto develop a plan for airway management and the subse-quent anesthetic technique.

Flexible bronchoscopy allows for dynamic assessmentof the upper airway during spontaneous respiration, aswell as for an evaluation of the peripheral tracheo-bronchial tree. It is particularly helpful for the evaluationof laryngomalacia, tracheomalacia, and bronchomalacia.Flexible bronchoscopy is performed soon after the patientloses consciousness so that spontaneous respiration ismaintained. It is commonly performed through a deviceattached to the anesthesia mask to allow concomitantinhalation of oxygen and inhalational anesthetic duringthe procedure.

A rigid bronchoscope is a stainless steel hollow tubethat is used for diagnostic and therapeutic procedureswithin the airway below the glottis.The distal end is blunt,and the proximal end contains a ventilation side-portthat attaches to the standard anesthesia breathing circuit.A thinner telescope with an optical eyepiece is placedcoaxially within the rigid bronchoscope and allows formagnified and illuminated visualization of the airway(primarily below the glottis) while retaining the abilityto provide adequate ventilation (Fig. 29-4).When the tel-escope is removed, instruments can be passed throughthe bronchoscope to retrieve foreign bodies,resect masses,etc., while maintaining oxygenation and ventilation.Therigid bronchoscope is particularly suited for difficult air-way management because of its ability to bypass laryn-geal and tracheal lesions that compress the airway andcontribute to difficult ventilation or intubation. It maybe life-saving in the case of a mediastinal mass that iscompressing the bronchial tree below the carina (seeChapter 8).

There are a variety of sizes and lengths of pediatricbronchoscopes that are chosen on the basis of the ageand size of the child (Table 29-1).The bronchoscope size

is chosen to give the surgeon the best possible viewwhile causing the least amount of trauma to the glottisand subglottic tissues.The time taken to perform bron-choscopy should be as short as possible to decreasethe risk of obstructive edema secondary to vocal cordand subglottic trauma. In some cases, the surgeon maychoose to examine the glottis and the subglottis with thetelescope alone to minimize trauma to this region. In thiscase, simultaneous ventilation is not possible;preoxygena-tion will increase the duration of apnea before hypoxiaintervenes.

Various successful methods have been reported foranesthetizing children for bronchoscopy. Anestheticinduction can be accomplished using inhaled sevoflu-rane or an intravenous hypnotic agent. Following loss ofconsciousness, and prior to airway manipulation, intra-venous and topical lidocaine can be administered to pre-vent the occurrence of protective airway reflexes suchas gag and laryngospasm. Topical lidocaine within thelower airway may precipitate reflex bronchoconstrictionunless preceded by intravenous lidocaine. Small dosesof an opioid can be carefully titrated to maintain sponta-neous ventilation, which is maintained during flexiblebronchoscopy to evaluate dynamic function of theairway. Spontaneous ventilation should always be main-tained with a potentially difficult ventilation or intubation.Neuromuscular blockers are administered only after ade-quate positive-pressure ventilation has proved success-ful.Flexible bronchoscopy is initially performed with thehead of the OR table facing the anesthesiologist, so thatmask ventilation can be optimally continued throughoutthe procedure.

The anesthetic plan for rigid bronchoscopy will belargely determined by the a priori choice of spontaneousor positive pressure ventilation during the bronchoscopy.This choice is influenced by the personal preferences ofthe anesthesiologist and surgeon, who must agree on anacceptable technique prior to administration of anesthesia.There are times,however,when this decision will be madeduring the case,depending on the surgeon’s findings andthe patient’s clinical condition. With either ventilatorymethod, these procedures entail a large percentage oftime that the child’s airway is open (i.e., exposed to theatmosphere when the surgeon removes the optical eye-piece or removes the bronchoscope). For this reason,a total intravenous anesthesia (TIVA) technique is pre-ferred to decrease OR pollution from inhalational agentsand provide an uninterrupted source of general anesthesiato the patient.

There are advantages and disadvantages of both spon-taneous and controlled ventilation methods during rigidbronchoscopy. If spontaneous ventilation is maintained,continuous ventilation is occurring, despite interruptionsin the anesthesia breathing circuit. For some obstructivelesions, negative-pressure breathing may provide better



oxygenation and ventilation.Disadvantages of spontaneousventilation include the requirement to maintain a suffi-cient depth of anesthesia to obliterate airway reflexesand prevent patient movement during instrumentation,yet maintain sufficient ventilatory function and hemody-namic stability.Thus, topical anesthesia to the airway isan important component of this technique.

A controlled ventilation technique, which usuallyconsists of administration of a neuromuscular blocker,relies on intermittent positive-pressure breaths betweenapneic periods when the surgeon instruments the airway,or uses the laser. Its advantages include the ability toprovide optimal oxygenation and ventilation during thebreathing phase, and assurance of lack of patient move-ment to airway manipulation. Its obvious disadvantage isthat during periods of apnea, even with preoxygenation,there is a limited time before oxyhemoglobin desaturationwill occur, and the child will require additional positive-pressure breaths.Another significant disadvantage is thelack of assurance that positive-pressure ventilation will besuccessful with an obstructive lesion within the airway.In the case of a foreign body lodged within the bronchialtree,a theoretical disadvantage of positive pressure is theunintentional movement of the object further distally.This can worsen airway exchange or create a ball-valveeffect with hemodynamic consequences secondary tolung compression of vascular structures. Fortunately, thiscomplication is extremely rare.

Once the child is adequately anesthetized, and justprior to performing rigid bronchoscopy, the OR table isturned 90 degrees away from the anesthesiologist, whilemask ventilation is continued by the anesthesiologistfrom a side position (Fig. 29-5) or by an assistant at thehead of the table until the surgeon is optimally preparedto instrument the airway.The goal of the entire processshould be a smooth, coordinated, sharing of the child’sairway with a combination of optimal oxygenation,ventilation, and surgical exposure.

Suspension Laryngoscopy

Suspension laryngoscopy is used mainly for proce-dures of the upper airway with the carbon dioxide laser.The child’s head is fixed in a constant position that pro-vides an optimal view of the larynx (Fig. 29-6).An endo-tracheal tube can be held in place by the suspensionlaryngoscope. If the endotracheal tube remains in placeduring the laser treatment, it must be wrapped withaluminum tape to decrease the chances of an airway fire.Alternatively, several commercial laser-safe endotrachealtubes are available. Removing the endotracheal tube dur-ing the laser treatments will optimize visualization forthe surgeon and remove a possible source of an airwayfire.Oxygenation and ventilation is then provided by oneof two methods: either intermittent endotracheal tube

placement between apneic laser treatments,or insufflationof oxygen using a jet ventilator device that is insertedinto the side port of the suspension laryngoscope proxi-mal to the glottis. The jet ventilator device is attached to astandard 50 psi wall outlet and a valve is used to decreasethe driving pressure required for adequate chest excur-sion (usually 10–15 psi) and to avoid barotrauma.The valveis manually opened 15–20 times per minute to providealveolar ventilation. Alternatively,spontaneous ventilationcan be maintained during laryngoscopy by insufflatingcontinuous 100% oxygen through the side-port of thesuspension laryngoscope. As with rigid bronchoscopy, aTIVA technique is preferred. Capnography is impossibleduring jet ventilation or insufflation techniques. If it isessential that PCO2 be monitored, transcutaneous carbondioxide monitoring will provide a reasonable estimate.

If suspension laryngoscopy is used in combinationwith the CO2 laser, all usual laser precautions should bestrictly followed. The child’s eyes should be securelycovered with wet saline gauze, and all skin surfaces arecompletely covered with sheets or drapes. If the endo-tracheal tube remains within the airway during the lasertreatment, it must be completely wrapped with aluminumtape or a commercially available laser tube should be used.If a cuffed endotracheal tube is used, the cuff should befilled with water or saline. Some anesthesiologists injectmethylene blue into the saline that goes into the cuff tobetter detect its breakage by the laser. Oxygen concen-trations should be as low as possible and N2O should beavoided to minimize combustibility.

Tracheostomy

The term given to creating a hole in the trachea is amatter of debate, with the names tracheotomy and tra-cheostomy used interchangeably. In general, tracheotomyis the temporary surgical cutting of the trachea throughthe anterior neck tissues, whereas tracheostomy entailsa more permanent opening into the trachea and place-ment of the tracheostomy tube.

Over the last decade, there has been a decrease in thenumber of pediatric tracheostomies being performed,largely due to improvements in airway management bypediatric anesthesiologists. However, with an increase inthe length of survival of children with complex medicalproblems, a new population of patients requiring tra-cheostomy is emerging. Several studies have shown thatonce a tracheostomy is placed, the duration that it is leftin place has increased over time due to the increasednumber of chronically ventilated children. A recent trendshows that the procedure is being performed in youngerchildren, with a peak incidence in patients aged under12 months.

The three most common indications for a tracheostomyin children are: (1) prolonged mechanical ventilation



(>50%), (2) upper airway obstruction (40%), and (3)pulmonary toilet (10%). Within each category there arecongenital, traumatic, metabolic, infectious, and neoplas-tic conditions that require tracheostomy. Although theunderlying medical conditions may be numerous, themost common diagnoses in pediatric tracheostomypatients are bronchopulmonary dysplasia and neurologicdisorders.

The decision to perform an elective tracheostomy iscomplex and depends on several factors, including thechild’s underlying medical condition, the severity of air-way obstruction, and the difficulty and length of intuba-tion. In general, a child who is chronically ventilated isinitially managed with an endotracheal tube, with thetiming of conversion to a tracheostomy somewhat age-dependent. Neonates may tolerate endotracheal tubeintubation for several months with minimal laryngealinjury owing to a more pliable airway.On the other hand,in older children and adolescents the laryngeal cartilageis firmer, requiring a tracheostomy to be performed after2–3 weeks of tracheal intubation.

In an emergency airway situation, procedures such asdirect endotracheal intubation and rigid bronchoscopyshould be attempted first. If these are unsuccessful,the next procedure of choice is cricothyrotomy, whichreduces the risk of injury to the esophagus and the majorneurovascular structures of the neck, compared to tra-cheostomy. In infants and children, the cricothyroidmembrane may be easily identified in experienced hands.Tracheostomy should be reserved as the last resort in anemergency pediatric airway management.

Early tracheostomy tubes were made of stainless steelor silver. These tubes had the advantages of causingminimal tissue reaction and avoiding tracheal collapse.However, their rigidity caused significant discomfort tothe patient owing to injury to the tracheal mucosa. Mostmanufacturers currently use plastic tubes that have min-imal tissue reactivity and conform to the structure ofthe airway.

The ideal tracheostomy tube should be made of amaterial that causes minimal tissue reactivity, can be eas-ily cleaned and maintained, and is available in a variety ofsizes and lengths.The tube needs to be rigid enough toprevent kinking or collapse, yet soft enough to be com-fortable for the patient.Modern tracheostomy tubes havea 15-mm male connector for the attachment of standardrespiratory equipment. The ideal tube also contains aninner cannula that may be removed and cleaned.

Tracheostomy tubes for small children do not containa cuff. In larger children and adolescents, cuffed adulttracheostomy tubes may be used. In selecting the appro-priate tracheostomy tube, both the diameter and lengthshould be considered.The external diameter determinesthe size of the tube that may be inserted,whereas the innerdiameter determines the actual airway size.The diameter

of the tube should be large enough to allow adequate airexchange, easy suctioning, and clearance of secretions. Ifthe indication for tracheostomy is assisted ventilation,the size of the tube should be adjusted to prevent excessiveair leak. Predictors of the appropriate tube size includethe child’s age and the size of a preexisting endotrachealtube. Too large a tube will compromise the capillary flowin the tracheal wall, which may result in mucosal ulcera-tion and development of fibrous stenosis. Overinflationof a cuffed tracheostomy tube for a prolonged periodmay produce similar injuries.This complication may beavoided by selecting the proper sized tracheostomy tube(Table 29-2) and adjusting the cuff pressure to less than20 cmH2O.The choice of the tube size is also influencedby visualizing the size of the tracheal lumen.

The length of the tube is important, especially inneonates and infants.A tube that is too short may resultin accidental decannulation or the development of a falsepassage.If a tube is too long,the tip may abrade the carinaor rest in the right main bronchus.Some plastic tubes maybe cut to the desired length.Extra-long custom-made tubesmay be helpful in unusual situations, such as tracheoma-lacia or tracheal stenosis, to span the involved area.

Unless airway obstruction is immediately life-threatening, pediatric tracheostomy procedures shouldbe performed in the operating suite.This creates a well-controlled environment for the child and the personnelperforming the procedure.The operating suite providesoptimal illumination,proper positioning of the child, andexpert nursing care. In addition, a full range of laryngo-scopes and bronchoscopes are available to control theairway if necessary.

In children with an indwelling endotracheal tube, thechoice of induction and maintenance of general anes-thesia is unimportant. However, if the tracheostomy isbeing performed for acute airway obstruction,principlesof difficult airway management will apply (Chapter 18).Prior to performing the procedure, the surgeon andanesthesiologist should discuss the method of choicefor obtaining and securing the airway. All alternativesshould be discussed in the event that the child cannotbe intubated successfully. It is preferred to perform thetracheostomy with the child intubated under generalanesthesia with paralysis. In certain situations of severeupper airway obstruction, it may be necessary to performthe tracheostomy with mild sedation and infiltration oflocal anesthesia.

The tracheostomy is performed supine with the child’sneck extended using a shoulder roll. The child should bebreathing 100% oxygen in anticipation of a temporaryinterruption of ventilation. If a nasogastric tube is pres-ent it should be removed so as not to alter normal neckanatomy. Lidocaine with epinephrine is infiltrated intothe subcutaneous tissue one to two fingerbreadths abovethe sternal notch. A horizontal skin incision is then made



at the same site. A vertical midline dissection is performedto expose the tracheal rings.Traction sutures are placedin a paramedian position at the level of the second orthird tracheal ring, to rapidly open the airway shouldaccidental decannulation occur before the tract is estab-lished.The trachea is incised vertically in the midline toexpose the underlying endotracheal tube.While directlyobserving the endotracheal tube, the anesthesiologistgradually pulls it back to just above the incision as thesurgeon inserts the tracheostomy tube. The anesthesiabreathing circuit is then connected to the tracheostomytube; correct placement is confirmed by listening forbilateral breath sounds and observing a normal capno-graphic tracing. Prior to these final confirmations, theendotracheal tube should never be completely with-drawn out of the trachea. Flexible bronchoscopy isthen performed to identify the distal position of the tra-cheostomy tube. Proper adjustment or possible replace-ment of the tracheostomy tube with a different size is doneat this stage.The previously placed endotracheal tube isremoved just prior to leaving the operating room or afterarrival at the intensive care unit. A postoperative chestradiograph is obtained to further confirm tube positionand rule out pneumothorax.

Postoperatively, humidified air by collar or ventilatoris provided to prevent excessive dryness and thickeningof tracheal secretions. The first tracheostomy tube changeis done on the fifth to seventh postoperative day after awell-formed tract has been established. The tractionsutures are also removed at this time.

Anesthesiologists should be aware of the variouscomplications related to pediatric tracheostomy.Bleedingcan occur from superficial tissues, thyroid vessels, orvascular anomalies such as a high-riding innominate artery,and can obstruct the surgeon’s view of the opened tra-chea.Air entry into the subcutaneous tissues may causea pneumomediastinum, pneumothorax, subcutaneousemphysema,or any combination of those. Anatomic injuryto the neurovascular structures in the neck, including therecurrent laryngeal nerve, can also occur. During place-ment, the tracheostomy tube can be unintentionallyplaced into a false lumen adjacent to the trachea, or intothe esophagus. For these reasons, the endotracheal tubeshould never be fully removed before final confirmationthat the tracheostomy tube is functional.

LOWER AIRWAY SURGERY

Bronchial Foreign Body

A variety of different types of edible and inedibleforeign bodies commonly become lodged in the distalbronchial tree.Toddlers are most affected because of theirunderdeveloped ability to coordinate swallowing of smallfood items such as peanuts. Bronchial foreign bodies are

likely to cause distal airway obstruction with developmentof emphysema, atelectasis, and pneumonia. Children maypresent with a respiratory illness that runs the gamut fromtachypnea and fever to respiratory failure and hypoxemia.A bronchial foreign body is suspected when a toddlerpresents with the sudden onset of respiratory distressthat usually begins with a choking episode.The foreignobject may or may not be observed. Confirmation of thediagnosis consists of radiological demonstration of theforeign body if it is radiopaque, or unilateral emphysemafrom a ball-valve effect of the distal obstruction.An aspi-rated peanut will exacerbate the condition by causing alipoid pneumonitis.

This procedure is usually considered a surgical emer-gency. Preoperative assessment should be focused ondetermining respiratory function, administration ofantibiotics, and bronchodilator therapy if bronchospasmis present. An intravenous catheter should be inserted.Intravenous midazolam can be titrated to achieve anxiol-ysis in the preoperative holding area under direct super-vision of the anesthesiologist. An anticholinergic agentshould also be administered.A rapid sequence inductionand tracheal intubation is indicated if a full stomach issuspected. Induction and maintenance of general anesthe-sia is the same as described above for rigid bronchoscopy,with a choice between spontaneous or controlledventilation.

NECK SURGERY

Thyroglossal Duct Cyst

A thyroglossal duct cyst is a small collection of fluid inthe soft tissue of the midline of the neck. It is believed tobe a remnant of the connection between the tongue andthe thyroid gland in fetal life. During childhood it canbecome infected and enlarged, and requires excision.These children are usually otherwise healthy.Preoperativeassessment, and induction and maintenance of generalanesthesia, are no different from usual.The anesthesiolo-gist may wish to place a towel wrap around the head withwhich to secure the endotracheal tube over the forehead.The child is positioned similarly to tracheostomy withthe neck extended for a transverse midline incision.Theanesthesiologist may be asked to depress the base ofthe tongue to move the cyst to facilitate surgical identifi-cation. Surgical risks include unintentional trauma tovascular or airway structures in the neck. Postoperativeconcerns include hematoma formation with subsequentairway compression.

Branchial Cleft Cyst

Branchial cleft cysts are found on the side of the neckand develop from a failure of involution of one of the



branchial clefts during embryonic development. Thesechildren are otherwise healthy;perioperative and postop-erative anesthetic implications are essentially the same asfor the thyroglossal duct cyst.

Neck Mass Biopsy and Excision

When unclassified neck masses in children do notrespond to conventional antibiotic therapy, an excisionalbiopsy is indicated to rule out malignancy or (rarely)tuberculosis. The vast majority of these cases are straight-forward; the anesthetic implications are described above.However, when a lymphoma is suspected, the anesthesi-ologist must be aware that there may be an occultanterior mediastinal mass that carries the potential forlife-threatening airway obstruction following inductionof general anesthesia (see Chapter 8).Preoperative symp-toms that are suggestive of an anterior mediastinal massinclude coughing or dyspnea in the supine position thatis relieved when the child assumes the sitting or pronepositions.

Cystic Hygroma

Another name for a cystic hygroma is a lymphangioma.It is a malformation of lymphatic vessels in and aroundthe neck region.They are strongly associated with Turnersyndrome, trisomy 21 (Down syndrome), trisomy 18(Edwards syndrome), and Noonan syndrome, althoughmany otherwise normal children are affected. Cystichygromas are often found at birth and tend to enlargeduring early childhood.The majority of children presentfor surgical excision for cosmetic reasons. The occasionalchild will present for reduction and/or tracheostomy dueto respiratory distress from airway compression (Fig.29-7).Cystic hygromas notoriously grow inward and compressthe airway. The preoperative assessment should alwaysinclude MRI examination to delineate its spread andevaluate airway patency. A hemoglobin level and type-and-screen should be obtained preoperatively if an exten-sive dissection and excision is planned, or if the mass islocated near the vascular structures of the neck. Induction


Article To Know

Groudine SB, Hollinger I, Jones J, DeBouno BA: New York State guidelines on the topical use of phenylephrine in theoperating room.The Phenylephrine Advisory Committee.Anesthesiology 92:859–864, 2000.

The pediatric anesthesia community was shocked with the report of an intraoperative death of an otherwise healthy4-year-old undergoing routine adenoidectomy. The course of events that led to this tragedy began with the intraoperativetopical instillation of phenylephrine into the child’s nasopharynx, and subsequent treatment of severe hypertension with abeta-blocker (labetalol). This publication summarizes the findings of a panel that was convened by the New York StateDepartment of Health to investigate this and other similar cases, to determine the mechanism of cause of death, and torecommend guidelines for future use of phenylephrine in the operating room.

Although it is becoming less frequent, some surgeons continue to use phenylephrine (0.25–1%) as a topical vasoconstrictorduring upper airway surgery.Total absorbed doses are difficult to calculate. However, there are a number of published reportsof systemic absorption of topical phenylephrine that resulted in severe hypertension. The New York State panel that reviewedthese cases noted a recurrent pattern associated with poor outcomes: the development of severe, refractory pulmonary edemaand cardiac failure following treatment with beta-blockers.Table 29-3, taken from this article, details these cases.

Table 29-3 New York State Phenyleprine Morbidity

Patient # Age (years) Phenylephrine (%) Hypertensive Treatment Pulmonary edema Cardiac Arrest

1 3 0.25 None Yes No2 4 0.5 L,AD Yes Yes3 7 0.25 L No No4 9 ?a L,AD Yes Yes5 23 1.0a AD, E, Ca Yes No6 26 0.5a L,AD Yes Yes7 36 1.0a AD Yes No8 40 1.0a AD Yes No9 47 0.5a L,AD Yes No

aLidocaine with 1:100,000 epinephrine was also injected into the surgical field.L, labelalol;AD, anesthesia deepened; E, esmolol; Ca, calcium-channel blockerReproduced with permission from Groudine et al: Anesthesiology 92:859–864. Published by Lippincott Williams & Wilkins. Copyright © 2000 American Societyof Anesthesiologists. All rights reserved.


Administrator

Table 29-3,

Administrator

AU: Since there is no table 29-4, we changed Table 29-4 to 29-3. Please check.

and maintenance of general anesthesia is practitionerdependent and will vary with the severity of the massand the degree of airway obstruction. Principles of man-agement of the difficult airway will apply if upper airwayobstruction is suspected. Intraoperative concernsinclude blood loss, fluid management, and hypothermiaif the dissection is extensive, and the possibility of nervemonitoring. A temporary urinary catheter should be placedif the procedure is expected to last more than 3–4 hours.

ADDITIONAL ARTICLES TO KNOW

Aouad MT, Siddik SS, Rizk LB et al:The effect of dexamethasoneon postoperative vomiting after tonsillectomy. Anesth Analg92:636–640, 2001.

Catlin FI, Grimes WJ:The effect of steroid therapy on recoveryfrom tonsillectomy in children. Arch Otolaryngol Head NeckSurg 117:649–652, 1991.

Furst SR, Rodarte A: Prophylactic antiemetic treatment withondansetron in children undergoing tonsillectomy.Anesthesiology 81:799–803, 1994.

Gallagher MJ, Muller BJ: Tension pneumothorax during pedi-atric bronchoscopy. Anesthesiology 55:685–686, 1981.

Goldstein NA, Armfield DR, Kingsley LA et al: Postoperativecomplications after tonsillectomy and adenoidectomy in chil-dren with Down syndrome.Arch Otolaryngol Head Neck Surg124:171–176, 1998.

Hawkins DB, Joseph MM:Avoiding wrapped endotracheal tubein laser laryngeal surgery: experiences with apneic anesthesiaand metal laser-flex endotracheal tubes. Laryngoscope1283–1287, 1990.

Helfaer MA, McColley SA, Pyzik PL et al: Polysomnography afteradenotonsillectomy in mild pediatric obstructive sleep apnea.Crit Care Med 24:1323–1327, 1996.

Holinger LD, Konior RJ: Surgical management of severe laryn-gomalacia. Laryngoscope 99:136–142, 1989.

Hudgins PA, Siegel J, Jacobs I et al: The normal pediatric larynxon CT and MR. Am J Neuroradiol 18:239–245, 1997.

Hunton J, Oswal VH:Anaesthesia for carbon dioxide laser laryn-geal surgery in infants. Anaesthesia 43:394–396, 1988.

Keon TP: Death on induction of anesthesia for cervical nodebiopsy. Anesthesiology 55:471–472, 1981.

Litman RS,Wu CL, Catanzaro FA: Ondansetron decreases emesisafter tonsillectomy in children. Anesth Analg 78:478–481,1994.

Litman RS, Ponnuri J, Trogan I: Anesthesia for tracheal orbronchial foreign body removal in children: an analysis ofninety-four cases. Anesth Analg 91:1389–1391, 2000.

Morton S,Rosen C,Larkin E et al: Predictors of sleep-disorderedbreathing in children with a history of tonsillectomy and/oradenoidectomy. Sleep 24:823–829, 2001.

Pappas ALS, Sukhani R, Hotaling AJ et al: The effect of preoper-ative dexamethasone on the immediate and delayed postoper-ative morbidity in children undergoing adenotonsillectomy.Anesth Analg 87:57–61, 1998.

Pounder DR, Blackstock D, Steward DJ: Tracheal extubation inchildren: halothane versus isoflurane, anesthetized versusawake. Anesthesiology 74:653–655, 1991.

Randall DA,Hoffer ME:Complications of tonsillectomy and ade-noidectomy. Otolaryngol Head Neck Surg 118:61–68, 1998.

Rowe RW, Betts J, Free E: Perioperative management for laryn-gotracheal reconstruction. Anesth Analg 73:483–486, 1991.

Satyanarayana T,Capan L,Ramanathan S et al:Bronchofiberscopicjet ventilation. Anesth Analg 59:350–354, 1980.

Splinter WM, Roberts DJ: Dexamethasone decreases vomitingby children after tonsillectomy. Anesth Analg 83:913–916,1996.


Article To Know Cont’d

Phenylephrine administration causes stimulation of alpha-1 receptors and increases total peripheral resistance byvasoconstriction. Administration of beta-blockers will impair the heart’s ability to maintain cardiac output by increasingcontractility and heart rate.This cardiac depression, coupled with the shifting of blood into the pulmonary vasculature, resultsin pulmonary edema as seen in the patients described in the article.

The following are this author’s recommendations for use of phenylephrine in children; they are adapted from thePhenylephrine Advisory Committee’s guidelines:1. Phenylephrine should not be used as a topical vasoconstrictor during airway procedures in children. Oxymetazoline,

0.025%, is equally effective and is not associated with adverse effects in children.2. If phenylephrine is used in children, the initial dose should not exceed 20 µg/kg. During its use, blood pressure and

pulse should be closely monitored.3. Phenylephrine-induced hypertension is transient and benign in otherwise healthy children. It should not be initially

treated unless it persists or results in electrocardiographic abnormalities or pulmonary edema. It is reasonable, however,to transiently increase the concentration of inhalational agent while closely monitoring hemodynamic status.

4. Antihypertensive agents that are direct vasodilators or α-receptor antagonists (e.g., nitroprusside, hydralazine) areappropriate treatments. Beta-blockers and calcium-channel blockers should be avoided since their use is associatedwith worsening of cardiac output and development of pulmonary edema.



Box 29-2 Anesthesia Protocol forTonsillectomy at The Children’sHospital of Philadelphiaa

Premedication

Oral midazolam 0.5 mg/kg; maximum dose 10 mg (forsmall children with sleep apnea, some anesthesiologistschoose to halve this dose)

Oral acetaminophen 10–15 mg/kg

Induction

Sevoflurane (8% and adjusted downward as child losesconsciousness)

N2O, 70% in oxygen – discontinued when intravenousaccess is established

Vecuronium 0.1 mg/kgMorphine 0.075–0.125 mg/kg

Maintenance

Desflurane (concentration titrated to hemodynamicvariables)

N2O, 70% in oxygen

Emergence

Reversal of muscle relaxant with neostigmine andatropine or glycopyrrolate

Extubation when awake

Adjuvant Intraoperative Therapy

Ondansetron 1–2 mgDexamethasone 0.5 mg/kg; maximum dose 10 mg

Postoperative

Morphine 0.05 mg/kg titrated to pain relief or onset ofsleep

Ondansetron 1–2 mg for continued emesisOxygen as needed to maintain SpO2 > 94% prior to

discharge from PACU

aAll medications are administered intravenously, except for premedication.

Box 29-1 LMA for Tonsillectomy

Advantages

Easy to insertAllows for lighter level of general anesthesiaSmoother emergence without tracheal stimulationCan be removed at completion of procedure prior to

patient regaining full consciousnessDecreased incidence of postoperative sore throat

Disadvantages

May retract more cephalad in pharynx and obscuresurgical view

Appropriate size for child may not fit under surgeon’smouth-opening device

May not completely protect against secretions enteringthe glottic opening

Table 29-1 Size Charactersitics of the RigidBronchoscope

Size Length ID OD Age(cm) (mm) (mm)

2.5 20 3.5 4.2 Premature3.0 20, 26 4.3 5.0 Premature, newborn3.5 20, 26, 30 5.0 5.7 Newborn to 6 months3.7 26, 30 5.7 6.4 6–12 months4.0 26, 30 6.0 6.7 1–2 years5.0 30 7.1 7.8 3–4 years6.0 30, 40 7.5 8.2 5–7 years6.5 43 8.5 9.2 Adult

ID, inner diameter; OD, outer diameter.Reproduced with permission from Bluestone D ed: Pediatric Otolaryngology,4th edn,WB Saunders, Philadelphia, 2003 (in press).



Table 29-2 Size Comparison of Endotracheal and Plastic Tracheostomy Tubes

Cannula Approx. French Inner Diameter (mm) Outer Diameter (mm) Overall Length

Endotracheal tubea

2.5 2.5 3.6 12 cm3.0 3.0 4.3 14 cm3.5 3.5 4.9 16 cm4.0 4.0 5.6 18 cm4.5 4.5 6.2 20 cm5.0 5.0 6.9 22 cm5.5 5.5 7.5 25 cm6.0 6.0 8.2 26 cmBivonab

2.5 12 2.5 4.0 30 mm2.5 12 2.5 4.0 38 mm3.0 14 3.0 4.7 32 mm3.0 14 3.0 4.7 39 mm3.5 16 3.5 5.3 34 mm3.5 16 3.5 5.3 40 mm4.0 18 4.0 6.0 36 mm4.0 18 4.0 6.0 41 mm4.5 20 4.5 6.7 42 mm5.0 22 5.0 7.3 44 mm5.5 24 5.5 8.0 46 mmFranklinc

3.5 3.5 5.0 44 mm4.0 4.0 6.0 44 mm4.5 4.5 6.7 48 mm5.0 5.0 8.0 51 mm5.5 5.5 8.5 54 mm6.0 6.0 9.3 57 mmPortex3.0 3.0 5.0 36 mm3.5 3.5 5.8 40 mm4.0 4.0 6.5 44 mm4.5 4.5 7.1 48 mm5.0 5.0 7.7 50 mm5.5 5.5 8.3 52 mmShileyd

00 Neonatal 3.1 4.5 30 mm00 Pediatric 3.1 4.5 39 mm0 Neonatal 3.4 5.0 32 mm0 Pediatric 3.4 5.0 40 mm1 Neonatal 3.7 5.5 34 mm1 Pediatric 3.7 5.5 41 mm2 Pediatric 4.1 6.0 42 mm3 Pediatric 4.8 7.0 44 mm4 Pediatric 5.5 8.0 46 mm

aThe endotracheal tubes are marked with the inner diameter, usually with the outer diameter, and with the length.bThe Bivona tube is manufactured by the Bivona Corporation of Gary, IN. Both the inner and outer diameters are marked on the tubes.cThe Franklin tube is of the Great Ormond Street design, manufactured in England and distributed by Inmed Corporation Norcross, GA. The tubes are stamped with justthe inner diameter.dThe Shiley tube is manufactured by Shiley Laboratories, Irvine, CA.The tubes are stamped with the size and inner and outer diameters.Reproduced with permission from Bluestone D ed: Pediatric Otolaryngology, 4th edn,WB Saunders, Philadelphia, 2003 (in press).



Figure 29-1 Anesthetic management of myringotomy tubeplacement. While maintaining mask ventilation, the anesthesiolo-gist turns the patient’s head to the side to allow the surgeon toperform the myringotomy and insertion of ventilating tubes byvisualizing the ear drum with a microscope. Upper airway obstruc-tion commonly occurs while the child’s head is turned.

Figure 29-2 Tonsillectomy positioning.The OR table is turned90 degrees away from the anesthesiologist.The surgeon inserts amouth-opening gag (a MacGiver device is shown in this photo)that stabilizes the oral RAE endotracheal tube on the chin. Duringmouth opening, the endotracheal tube can become compressed orkinked, or unintentional trauma to the mouth or lips may occur.

Figure 29-3 During dental and oral surgery procedures, a nasalRAE endotracheal tube is secured to the forehead using a headwrap. Care is taken to ensure that the bend of the tube does notabut against the tip of the nose, to prevent compression ischemia.

Figure 29-4 Rigid bronchoscope. The distal end of the rigidbronchoscope is blunt, and the proximal end contains a ventilationside-port (D) that attaches to the standard anesthesia breathingcircuit.A thinner telescope with an optical eyepiece (B) is placedcoaxially through the proximal end and allows for magnified andilluminated visualization of the airway.The rigid bronchoscope asshown contains additional ports for attachment of a light source(A) and a suction port (C).



Figure 29-6 Suspension laryngoscopy. The child’s head andneck are fixed with the suspension laryngoscope to provide optimalvisualization of the larynx.

Figure 29-5 Anesthesia for rigidbronchoscopy.Once the child is ade-quately anesthetized, and just priorto performing rigid bronchoscopy,the OR table is turned 90 degreesaway from the anesthesiologist,while mask ventilation is continuedby the anesthesiologist from a sideposition or by an assistant at thehead of the table until the surgeon isprepared to instrument the airway.

Figure 29-7 Large cystic hygroma. This child required tra-cheostomy to relieve airway compression from a large cystichygroma.


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CHAPTER Anesthesia for Pediatric ENT Surgerytchanesthesia.org/uploads/3/1/9/5/3195694/29... · way management during tonsillectomy.Advantages and disadvantages of LMA use during tonsillectomy