62% of candidates passed this question.

In addition to the key PK and PD properties of each drug, a clear comparison was required to score well (why choose one drug over the other?). When a table was used the addition of a comparison column was helpful.

A good answer covered the following: ketamine has analgesic properties whilst midazolam does not; ketamine preserves airway reflexes and does not cause respiratory depression unlike midazolam; whilst ketamine increases cerebral blood flow and CMRO2, midazolam decreases it; ketamine has a direct myocardial depressant effect which is often offset by an increase in sympathetic tone, whilst midazolam has no direct cardiac depressant effects but may reduce BP due to reduced SVR; midazolam has anticonvulsant properties, ketamine does not; ketamine is a bronchodilator; both drug effects are offset by redistribution; midazolam is lipophillic at body
pH and will accumulate with prolonged infusions, ketamine will not; both are metabolised in the liver; midazolam can be reliably reversed by flumazenil, whereas there is no reliable complete reversal of ketamine; midazolam exhibits tolerance, dependence and withdrawal, whereas patients will only experience tolerance to the analgesic properties of ketamine.

“Drugs in Anaesthesia and Intensive care” chapters on midazolam and ketamine outline the key facts to include in this answer; interpretation and comparison of these facts will help achieve a good mark.