Anaesthesia for Obstructive Airway Disease

Anaesthesia for Obstructive Airway DiseaseDr Prasanga Palihawadana (MD, FRCA)Consultant AnaesthetistGeneral Hospital Ampara

Areas coveredPathophysiologyMedical ManagementAssessment of Bronchial AsthmaPreparation Anaesthesia

Areas covered..Management of Acute Severe Asthma in OT

COPDPrinciples of MxPrevious exam questions

Bronchial AsthmaA chronic inflammatory condition of lungs.Common -10%

SymptomsCoughWheezeChest tightnessSOB

Characteristic featuresAirflow limitationAirway hyper responsivenessInflammation

CausesAtopy- Enviornmental Pollen Dust PollutionViral infections

CausesCold airEmotionsOccupationalDrugs - NSAIDS Beta blockers

PathophysiologyInflammation (Steroids)Bronchoconstriction (beta2 agonists)Cholinergic effect causing Bronchoconstriction(Ipratropium=atropine)

PathophysiologyHistamine H1=Bronchoconstriction(mast cell stabilisers)Leucotrines in aspirin induced asthma

Management of BA (WHO guidelines)Lifestyle modificationStepwise Rx with,Inhaled beta agonists sosRegular inhaled steroids Plus regular beta agonists

Drug Treatment (preferably as inhalers)Beta 2 agonists Salbutamol, Salmeterol, terbutalineSteroids- Beclamethasone etcMast cell stabilisers- Sodium chromoglycate

Treatment contd.Anticholinergics- Ipratropium Theophylline preparationsOral steroidsLeucotrine receptor antagonists

Assessment of BA Pts

DurationSymptomsPrecipitantsRx & Compliance

Assessment of BA patients..Effect on daily lifeAcute attacks- Nebulisations Hospitalisation ICU admissions, ventilationPrevious anaesthetics

Examination & InvestigationsGeneral examinationLung signsPEF and reversibility

Investigations

CXRAY if indicated

Lung function tests-FEV1/ FVC

Preparation and AnaesthesiaAllay anxietyContinue RX bring inhalers to OTOptimise medical Mx if not under control

Preparation & anaesthesiaTreat infectionsStop smokingNebulize before OTIV steroids- hydrocortisone 100mg

Choice of anaesthesia- GA vs RegionalNeed to have minimal lung signs for bothSpinal will avoid multiple drugs/ stimulation of airwayEpidural Avoid high blocks

GAHow the anaesthetic is given is more important than what the agent isSafe drugsPropofolKetamine(add atropine)EtomidateMidazolam

Safe drugs in BA..FentanylPethidineVecuroniumSuxVolatile agents

Possible precipitants?TPS? morphine? Atracurium

Possible precipitants..ProtamineNeostigmineDiclofenac/ aspirinAntibiotics

During anaesthesiaTry to avoid intubation- Face mask/ LMAMaintain adequate depthAvoid stimulation under light anaesthesia (ETT/surgery)Secretions may precipitate

Intra op management..Ventilate with- Slow RR/moderate Vt; I :E> 1:2 Monitor SPO2, ETCO2, AWPAvoid reversalDeep extubation

Asthmatic attack under GA

High AWPTight bagDesaturationUpsloping ETCO2

Possible causes..Anaphylaxis/ other hypersensitivity reactionAspirationPneumothoraxEndobronchial ETT/ circuit occlusion

Management

Increase oxygen flow while maintaining depthIncrease volatile agent (halothane)Remove precipitant

Management contd.Nebulise with -5mg salbutamol 0.5mg Ipratropium(need circuit adaptor/oxygen driven neb)Steroids- 200 mg Hydrocortisone IV

Drug RxAminophylline IV- 5mg/Kg bolus in dextrose/20 min(250 mg in a vial)Follow up infusion at 0.5mg/Kg per hourSalbutamol IV infusion

Second line drugs

Ketamine 0.5mg/Kg IVMGSO4- 2g IV/ 30min

COPDChronic bronchitis & emphysemaAbnormal lungsSmoking/ other factors

COPD..InfectionsHyperinflated lungsCor-pulmonale

Features of COPDPink puffers=compensatedBlue bloaters=decompensatedAirway obstruction is not completely reversibleRx- Beta 2 agonists/ steroids/ diuretics

Assessment

Functional capacityHow many pillowsCXRAYArterial blood gasesLFT

AnaesthesiaHigh riskAvoid elective surgery if not well controlledStop smokingRx InfectionSteam, Chest physio

Regionals when possible

GA= BA

Post op ICU

Controlled oxygen therapy

Exam QuestionsAnaesthetic management of BA patient for elective surgeryAcute asthmatic attack under GAShort notes on salbutamol/ aminophylline

Thank you!