EDAIC I MCQs (all topics) with simplified explanations. Free weekly upload by www.targetedaic.com.

1. 50% oxygen
2. 0.5ml of adrenaline 1:10,000 intramuscularly
3. 0.5mg of adrenaline intravenously at a rate of 0.5mg/min until a response is obtained
4. Chlorpheniramine 10-20mg by slow intravenous injection
5. Hydrocortisone 100-300 mg intravenously

A 1.FALSE 2.FALSE 3.FALSE 4.FALSE 5.FALSE

Explanation: Anaphylaxis is a rare event during anaesthesia. Clinical features include cardiovascular collapse, bronchospasm, angioedema, generalised oedema, cutaneous signs like a rash, erythema, urticaria, etc.

Initial therapy:

1. stop administration of drug,
2. 100 % oxygen, maintaining airway,
3. inj adrenaline : IM 0.5mg (0.5 ml of 1:1000) or 0.01mg/kg , repeated every 10min, IV : 50-100 mcg (0.5 ml of 1:10,000) over 1min with titration of further doses.
4. If cardiovascular collapse occurs, start intravenous adrenaline infusion at a rate of 0.1 mg /min ,
5. start volume expansion with Normal saline 20ml/kgover 1-2 min under pressure.
6. Secondary therapy involves administrating
   1. antihistaminic,
   2. steroids ( prednisone),
   3. beta mimetic drug(salbutamol ) in case of bronchial asthma
   4. In patients with expected obstruction of airways: inhalation epinephrine preparation with a spray head for drug vial
7. Observe for a minimum of 4 hrs.

1. Platelets form the greatest bulk of the thrombus
2. Sickle cell anaemia is a cause
3. A positive Homan’s sign is diagnostic
4. Pulmonary embolism is commonest with thromboses below the knee
5. Destruction of vein valves is accompanied be deem

1. FALSE 2. TRUE. 3. FALSE 4.FALSE 5.TRUE

Explanation: A thrombus consists mainly of red cells and fibrin(red thrombus). Sickling in sickle cell crisis leads to increased blood viscosity which is associated with both arterial and venous thrombosis. Homan’s sign, pain in calf on dorsiflexion of the foot, also occurs with other lesions of the calf. Pulmonary embolism is most common with DVT from an iliofemoral thrombosis, and rare with those below the knee. In DVT, deep vein valve destruction leads to painful swollen limb, oedema and venous eczema.

1. Atmospheric pressure decreases linearly with increasing altitude
2. Hyperpnoea enhances oxygen uptake in the lungs and its offloading in tissues
3. At 10,000 feet,50% N2O will be less analgesic than at sea level
4. For the same minute ventilation, work of breathing will be reduced compared to sea level
5. Halothane vaporisers will have to be manually adjusted to compensate for altered atmospheric pressure.

1.FALSE 2.FALSE 3.TRUE 4.TRUE 5.FALSE

Explanation: There is a non-linear relationship between falling atmospheric pressure with rising altitude. Hyperpnoea due to hypoxia leads to a left shift of Hb-0₂ dissociation curve causing improved uptake of 0₂ by blood in lungs but making its offloading in tissues less efficient. Analgesic effects of N2O depend on its absolute partial pressure which will be less for the same % when at an increased altitude (due to reduced atmospheric pressure, and hence partial pressure, with the same composition of gases). Reduced gas density at higher altitude reduces breathing resistance and therefore work of breathing. Halothane vaporisers compensate for a change in atmospheric pressure and still produce the same partial pressure of halothane in the outflow.

1. Ventricular tachycardia
2. Asystole
3. Atrial flutter
4. Digoxin toxicity
5. Bundle branch block

1.TRUE 2.FALSE 3.TRUE. 4.FALSE 5.FALSE

Explanation: Major difference between cardioversion and defibrillation is that the former is synchronised so that shock occurs during the downstroke of QRS complex. In Asystole, cardioversion is not indicated unless ventricular fibrillation can’t be excluded. Atrial flutter and fibrillation (of onset<1 year) are indications for cardioversion. Digoxin toxicity may lead to ventricular arrhythmias or asystole following cardioversion. Therapeutic digoxin levels don’t increase risk of this but it is conventional to omit digoxin several days prior to planned cardioversion.

1. The stump is heated to provide a vapour pressure of 10% above atmospheric pressure
2. The vapour circuit gas flow is not determined by the fresh gas flow
3. Compensation for changes in atmospheric pressure are by manual adjustment
4. The working pressure of the vaporiser increases linearly with increased gas flow
5. Is not possible in event of power failure

1. FALSE 2.TRUE 3.TRUE 4.TRUE 5.TRUE

Explanation: It is a non-variable, bypass-type vaporiser allowing desflurane to be used despite its high volatility and moderate potency. Its stump is heated to 39*c at which vapour pressure is twice the atmospheric pressure at sea level. This pressure provides vapour circuit gas flow which is independent of fresh gas flow. Tec 6 requires manual adjustment for changes in atmospheric pressure to avoid a fall in the absolute partial pressure of anaesthetic for a certain % setting at an increased altitude. Working pressure of vaporiser increases linearly with the fresh gas flow to maintain output independent of fresh gas flow.