ANESTHESIA FOR ORTHOPEDIC,ENT AND MAXILLOFACIAL SURGERYPresented by-DR.POOJA

Moderator-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 SURGERY

Op. 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 SURGERY

Potential to contaminate lower airway with blood and secretions

Airway is secured with tracheal tube and throat pack is inserted

Extubation 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 ALGORITHM

1.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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