Resp - Asthma

Question 1

Define asthma

Answer 1

Chronic inflammatory disorder of the small airwaysPresents as breathlessnewss, wheeze and cough with diurnal variationVariable reversible obstruction demonstratedFEV1/FVC< 65%FEV1< 70%Or improved ratio by 12% after inhlalers

Question 2

Patholophysiology

Answer 2

Chronic airway inflammationSmooth muscle hypertrophyLeads to goblet cell hyperplasiaIncreased airway reactivity, mucosal oedema and secretions +++BRONCHOSPASM and MUCOUS PLUGGING —> scarring

Question 3

Define moderate acute

Answer 3

PEFR > 50-75% best/predictedIncreasing symptomsNo features of severe

Question 4

Define severe acute

Answer 4

1 of:PEFT 33-50%RR>25HR > 110/minCant complete sentence

Question 5

Define life threatening

Answer 5

Any one Signs or Investigation in patient with severe

Signs 										IxAltered GCS							PEFR<33%Exhaustian							SpO2<92%Arrhytmia								PaO2<8kPaHypotension							Normal CO2CyanosisSilent ChestPoor Effort

Question 6

Define near fatal

Answer 6

Raised CO2 +/- requiring mechanical ventilation| Raised inflation pressures

Question 7

Management

Answer 7

ABCDE treating life threatening isses as foundLiaise with anaesthesia, resp A - assess airwayB- 100% with Sats 94-98% Perform ABG CXRNebs - salbutamol 2.5-5mg Ipratropium 250-500mcg nebsSteroids - 40mg or 100mg hydrocortisoneMagnesium 8mmol over 20 minutesIv salbutamolAminophyline in life threatening

Question 8

Indications of I&V

Answer 8

Poor/worsening resp effortExhaustionPersistant hypoxiaDrowy/confusedResp arrest

Question 9

Drugs for intubation

Answer 9

Ketamine 1-2mg/kg induction| Avoid atracuiusm - istamine

Question 10

Circulatory considerations

Answer 10

Usually intravascular depletionCO drops as rising intrathoraci pressure impedes venous returnBeware loss of sympathetic drive when inducedTherefore fluid resusMonitor electrolytes and correct

Question 11

Ventilation in asthma

Answer 11

High airway resistanceExpiratroy flow restricted —> breath stacking/air trapping (dynamic hyperinflation)(Barotrauma, and CVS depression)Vent strategy

Low PEEP (80% of intrinsic PEEP in spont patients)Measure intrinsice on expiratory hold and apply extrinsic accordingly

Prolong IE time 1:2 to 1:4Hypovent: Slow RR 10-14 Low Tv 5-7mls/kg Plataeua pressure < 30cm H20 Allow permissive hypercapnia so long as pH>7.2Manual deceopression

Question 12

Adjunctive therapies

Answer 12

Ketamine 0 as infusion, causes bronchodilationSevoflurane/volatileVV ECMO

Question 13

NIV in asthma

Answer 13

InconclusiveNot establsihed evidenceLow threshold for tube is doing it

Question 14

Risk for near fatal asthma

Answer 14

Previous ICU admission/I&VOral steroid useIncreasing salbutamol usePoor complianceAge over 40

Question 15

Types of Brittle asthma

Answer 15

Type 1 - >40% diurnal variation for 50% of the time despite txType 2 - Sudden severe attacks on a background of well controlled