MCQ MAHE 2000 Anesthesia Answer 2

The Correct Answer is A

Halothane exists as a volatile liquid with a distinctive aroma and is added to the gas mixture delivered to the patient by means of a vaporizer added to the anesthesia machine. It is a comparably stable compound, nonflammable, and easy to vaporize.


Halothane has profound effects on various body systems. In addition to depressing consciousness, halothane reduces or eliminates the sympathetic response to painful stimuli. This depressant effect on the sympathetic nervous system also reduces the protective baroreflex response to conditions such as hypovolemia. Depression of the respiratory drive is also produced by halothane. Both the central response to carbon dioxide and the peripheral response to tissue hypoxia are depressed.

The pattern of respiration produced by halothane is rapid, shallow, and monotonous with no sighs. Such a pattern predisposes to atelectasis. Halothane also depresses protective airway reflexes thereby placing the patient at higher risk of aspiration at induction.

Halothane directly decreases myocardial contractility and heart rate and slows conduction through the AV and ventricular Purkinje system. Although some vasodilation occurs with halothane, the hypotension produced by this agent is primarily the result of myocardial depression and decreased cardiac output.

Exogenous doses of catecholamines (e.g. during facial plastic surgery) may produce severe ventricular dysarrhythmias due to the myocardial sensitization. Halothane also results in muscle relaxation and can result in potentiation of paralytic agents.

Category: MAHE 2000 MCQs