ANESTHESIA FOR ORTHOPEDIC,ENT AND MAXILLOFACIAL SURGERYPresented by-DR.POOJAModerator-DR.GIRISH SHARMA
ANESTHESIA FOR ORTHO SURGERY Patients range from elderly patient with
multiple co morbid conditions to a young apparentely healthy patient
All patient need a thorough pre-op evaluation Challenges include - difficult airway - large blood losses - positioning -significant post-op pain
ELDERLY PATIENT
ELDERLY PATIENT
Are more prone to cardiac, pulmonary complications and dementia/delirium
cardiac complications because of-Co morbid condition-Limited functional capacity-Significant blood loss and fluid shift-Systemic inflammatory response-Post op pain
All these trigger a stress response leading to tachycardia, hypertension, increased O2 demand and myocardial ischemia.
pulmonary complications due to - Age related changes in lung mechanics - Decrease in arterial O2 tension - Decrease of 10% in FEV1 with each decade of
life -Increase in closing volume
Confusion or delirium-risk factors include-
- advancing age - alcohol use - pre op cognitive impairment - periop hypoxemia - hypotension - hyper volemia - electrolyte imbalance - infections - sleep deprivation - pain - medications
Strategies to reduce incidence include -identifying risk factors -adequate pain control -mobilization -maintaining normal sleep -avoiding psychotropic medications
SPECIAL CONSIDERATION Fat Embolism Syndrome Pneumatic Tourniquets Deep Vein Thrombosis and PE Bone Cement Implantation Syndrome
FAT EMBOLISM SYNDROME Fat embolization is a well known complication of
skeletal trauma and surgery involving femoral medullary canal
FES is a physiologic response to fat within systemic circulation
Embolization occurs in almost all patients with pelvic or femoral fracture but FES in <1%
.
GURD,S DIAGNOSIS- major feature(at least one) respiratory insufficiency,
cerebral involvement, petechial rash Minor features(at least four) pyrexia, tachycardia, retinal changes, jaundice, renal changes LAB features- Fat microglobulinemia (required) anemia, thrombocytopenia, high ESR
SCHONFELD FES INDEX Petechial rash 5 Diffuse alveolar infiltrate 4 Hypoxemia PaO2<70mmHgFiO2100% 3 Confusion 1 Fever>38C 1 HR>120 1 RR>30 1 Score >5 is diagnostic
It can be gradual over 12-72hrs or fulminant
leading to ARDS and even cardiac arrest Treatment includes – -early stabilization of fracture -O2 therapy -early mechanical ventilation before
respiratory failure -Steroid therapy may be benefecial
PNEUMATIC TOURNIQUETS Used to create blood less field Inflation pressure is 100mm above systolic BP Prolonged inflation (>2hrs) leads to -transient muscle dysfunction - rhabdomyolysis, -nerve injuries Exsanguination of extremity causes shift of blood
volume into central compartment , rise in CVP and arterial BP that may not be well tolerated in pat. with LV dysfunction.
.
Tourniquet pain –even during GA manifesting as increasing MAP beginning about ¾-1hr of cuff inflation
Cuff deflation causes fall in CVP and arterial BP
Washout of metabolic wastes in ischemic extremity increases PaCO2, ETCO2,lactate and potassium levels
Can cause increase in minute ventilation and rarely dysrythmias
DVT and PE may develop
DEEP VEIN THROMBOSIS AND THROMBO EMBOLISM Risk factors include -obesity -age >60 -lower extremity fracture -tourniquet use -immobilization >4days Prophylactic anticoagulation ,pneumatic leg
compressions ,early mobilization reduce the incidence
BONE CEMENT IMPLANTATION SYNDROME
Manifesting as hypotension, hypoxia, FES or even cardiac arrest
Mech. Includes -embolization of bone marrow debris during
pressurization of femoral canal -toxic effect of methyl methacrylate -release of cytokines Risk factors are -revision surgery -pathological fracture -preexisting pulmonary hypertension -quantity of cement used
Strategy to minimize - - increasing FiO2 prior to cementing - maintaining euvolemia - high pressure lavage of femoral shaft - creating vent in distal femur - cement less prosthesis
SPECIAL CONDITIONS RHEUMATOID ARTHRITIS – -airway(limited TMJ movement, narrow
glottic opening) -Cervical spine (atlanto axial instability)-pre op
flexion extension x-ray in limited neck movement if instability exceeds 5mm awake fibroptic intubation with neck stabilization
-Cardiac(pericarditis , tamponade)-Pulmonary(interstitial fibrosis)-Renal insufficiency
ANKYLOSING SPODYLITIS-chronic inflammatory arthritic disease resulting in axial skeleton fusion
airway management difficult due to reduced movement of cervical spine and TM joint
Neuraxial anesthesia difficult because ossification of spinal ligament closes inter vertebral spaces which may block acces to epidural and spinal space In some cases caudal may be feasible
ACHONDROPLASIA-dwarfism ,kyphoscoliosis and fo ramen magnum stenosis Chronic hypoxemia hypercarbia due to airway obstruction leads to pulmonary hypertension
-awake fibroptic intubation is safe - Echo should be obtained to asses pulmonary
hypertension and intracardiac shunts -aggravating pulmonary hypertension is to be avoided
OSTEOGENESIS IMPERFECTA -fragility of tissues and bones require
extreme care in positioning and padding during anesthesia
-Intubation with minimal neck manipulation -Sch avoided because fasiculations can
cause fractures -Bleeding status should be evaluated
because of platelet abnormality -Aggressive hydration because of risk of
hyperthermia and MH
REGIONAL VERSUS GA Reduced incidence of DVT and PE Less blood loss Less respiratory complications Superior post op analgesia Conscious pat aid in comfortable positioning Manipulation of airway avoidedFull anticoagulation is a contraindication
Interval of 12hrs bw LMW and neuraxial block Epidural catheter removal 8-12hrs of LMW Admn and 1-2hrs before next admn
SPINAL SURGERIES Problems include related to positioning-
airway management difficult Eyes pressure CRAO, CRVO, corneal
abrasion Neck rotation –compromized blood flow to
brain Large blood losses-controlled hypotensive
anesthesia is used. adequacy of end organ perfusion to be maintained with invasive BP,UO and ABG analysis
ANESTHESIA FOR ENT SURGERIES Clear, free, unobstructed airway is the
principal concern of these procedures Pt. may present with airway obstruction or
distorted anatomy During surgery anesthetist is away from
airway making adjustment difficult Significant head extension and lateral
rotation may be required During intraoral procedures ,instruments to
open mouth obstruct airway Airway requires protection from blood and
secretions in intraoral and nasal procedures
EAR SURGERYOp. range from short procedures to more long and
complex procedures Anesthetic factors are- -Choice of airway -Use of nitrous oxide -Head and body position -Facial nerve monitoring -Adequate surgical field -Nausea and vomiting -DVT prophylaxis -Temp. control
For long procedures tracheal tubes are used to secure the airway. Reinforced tubes may be used to prevent kinking with head rotation
Nitrous diffuses to airspaces in body it can diffuse into middle ear cavity increasing pressure and upon discontinuation rapid absorption leading to negative pressure resulting in graft displacement so avoided during graft procedures
Head up tilt of 15 degree is useful to reduce venous pressure and improve operating field
Lat. tilt of OT table helps prevent extreme rotation of neck
For facial nerve monitoring it may be required to reverse the NM block
High incidence of PONV so adequate hydration and prophylactic anti emetics
NASAL SURGERYPotential to contaminate lower airway with blood
and secretionsAirway is secured with tracheal tube and throat
pack is insertedExtubation is done awake or deepAwake involves removal of tube when pt. responds
to commands and make attempts to remove the tube
advantages is airway control in awake pt. with return of laryngeal reflexes
Disadvantages include high incidence of coughing, bucking,de saturation , laryngo spasm
deep extubation leaves unprotected airway pt. is dependent on oro pharyngeal airflow due to nasal packing
recovery with a LMA
At end of surgery pack should be carefully
removed Laryngo scopy followed by neck flexion to
encourage any clot to fall past soft palate and direct visualization of suction catheter going behind soft palate
Any clot left behind can be aspirated after tube removal causing total airway obstruction and death called coroners clot
Endoscopic procedures for vocal cord pathology including polyp,
nodules, tumours ,tracheal stenosis Preoperative airway assesment information about sub glottic ,tracheal
lesions by CXR,CT,MRI
sedative premedication avoided in airway obstruction
profound muscle paralysis to provide masseter muscle relaxation for introduction of scope and immobile surgical field
OXYGENATION AND VENTILATION- Most commonly pt. is intubated with small
diameter tracheal tube If intubation interfering with procedure ,there are
various non intubation techniques
Spontaneous ventilation and insufflation tech.-useful in FB aspiration,glottic and sub glottic lesions removal
O2 admn by facemask with inhalation induction and spontaneous ventilation
Small catheter introduced into nasopharynx Tracheal tube cut short ,placed in nasopharynx
just beyond soft palate Nasopharyngeal airway Side-arm of laryngoscope or bronchoscope
JET VENTILATION TECH. attachment of jetting needle to
laryngoscope for supra glotic insufflation Trans tracheal jet ventilation through
percutaneous catheters sub glottic ventilation through catheter or
tube placed in glottis
LOCAL ANESTHESIA OF AIRWAY If awake intubation is needed , local
anesthesia of airway can be used Block of superior laryngeal nerve b/l with
trans laryngeal injection of LA provides anesthesia from infra glottic area to epiglottis
SUPERIOR LARYNGEAL NERVE BLOCK-hyoid bone displaced laterally to the side to be blocked 25G 2.5cm needle walked of greater cornu of hyoid bone inferiorly and advanced 2-3mm As it passes through thyro hyoid membrane LOR is felt 3ml LA injected
TRANSLARYNGEAL BLOCK-cricothyroid
membrane is located 20G or smaller catheter over needle is introduced into midline .Inner cannula is withdrawn ,catheter held firmly in place,air is aspirated 3-5ml of 4%lignocaine is injected
Vigorous cough results which aid in spread of LAGLOSSOPHARYNGEA NERVE BLOCK-22G spinal
needle is used to inject LA into post. Tonsillar pillar
INTRAORAL SURGERIES- Tonsillectomy is frequentely performed
procedure pre op evaluation to identify OSA, active infection, bleeding tendency ,anemia
Surgery be postponed for RTI Sedation to be avoided in OSA Adequate depth of anesthesia to be
maintained
EXTUBATION- After careful inspection and laryngoscopy to
ensure no blood clots are present child placed in left lat. or semiprone head
down position pillow is placed under chest to drain
secretions chances of laryngospasm are greater –
topical airway ,increasing depth of anesthesia, subhypnotic doses of propofol or lidocaine can be used
Chances of rebleeding are greater in first six hours
Problem because of hypovolemia,aspiration risk and difficult laryngoscopy
Senior’s help should be requested O2 started, adequate resuscitation,
hematocrit and coagulation checked ,blood cross matched
Large bore iv asses established
RSI is preffered tech. Difficult laryngoscopy intubation anticipated Small tracheal tube should be available Tracheostomy set with surgeon should be
there Gastric tube should be inserted to
decompress stomach Extubation should be done fully awake
ANESTHESIA FOR MAXILLOFACIAL SURGEY Priority is to clear and secure the airway Severe bleeding can occur and there is risk of
aspiration of blood, bone,loose teeth ,soft tissue fragments
Detailed preop airway evaluation focussing on jaw opening , mask fit , neck mobility , maxillary protrusion , nasal patency , intraoral lesions, micrognathia , macroglossia
If problem with mask ventilation or intubation,airway should be secured prior to induction
This may involve-fibroptic nasal intubation-fibroptic oral intubation-tracheostomy Nasal intubation should be avoided in
maxillary fractures because of associated basillar skull fracture and CSF rhinorrea
Intra op head up position , controlled hypotension , local infiltration with epinephrine soln.
Two iv lines should be established oropharyngeal pack should be inserted
Anesthetist is remote from airway as surgical field is near airway. Airway monitoring of end tidal CO2,peak inspiratory pressures , esophageal stethoscope breath sounds are important
At end pack to be removed with proper suctioning
Extubation is to be done once patient is fully awake
If chance of post-op edema of structures interfering with airway, patient is to be left intubated
DIFFICULT AIRWAY ALGORITHM1.ASSES BASIC MANAGEMENT PROBLEMA .Difficult ventilation B. Difficult intubationC. Difficult patient co operationD. Difficult tracheostomy2.ACTIVELY DELIVER SUPPLEMENT O2 THROUGHOUT
DIFFICULT AIRWAY MANAGEMENT3.CONSIDER BASIC MANAGEMENT CHOICESA.Awake vs intubation after GAB.Noninvasive vs invasive technique for initial
approach to intubationC.Preservation of spontaneous ventilation vs ablation
a-surgery with facemask or LMA, local infiltration, regional nerve block
b-cricothyrotomy or tracheostomyc-use of different laryngoscope blades, stylets,
tube changers, lightwand, fibroptic,retrograde, blind technique
d-cancel surgery e-noninvasive ventilation-rigid
bronchoscopy,transtracheal jet ventilation ,combitube
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