A Comparative Study of Dexmedetomidine and Midazolam in Reducing Delirium Caused by Ketamine

Ketamine is a well known agent for sedation for short surgical procedures due to its very good analgesic action. But it has cardio stimulatory response and recovery from anaesthesia after Ketamine use is complicated by delirium and hallucination. In studies it is proved that these side effects can be reduced by premedication with benzodiazepines. The α2 adrenoceptor agonists are becoming popular for their properties like haemodynamic stability and reducing anaesthetic requirement.

This study was planned to see the effects of Dexmedetomidine on emergent reaction of Ketamine, when used as premedication agent with Ketamine for conducting short surgeries in adult patients.

Study was conducted in 90 ASA class I and II male and female patients of age between 18-40 undergoing short procedures like laparoscopic ligation, skin grafting, dilatation and curettage, endoscopic procedures, excision of small swelling, etc. Patients were randomly divided into three groups of 30 each as follows: Group K: after premedication with inj. glycopyrrolate 0.01mg/kg, inj. Ketamine 2mg/kg, Group M: after premedication with inj. glycopyrrolate 0.01mg/kg and inj midazolam 0.05mg/kg, inj. Ketamine 2mg/kg, Group D: after premedication with inj glycopyrrolate 0.01 mg/kg and inj. Dexmedetomidine 0.5μg/kg, Ketamine 2mg/kg was given. Observations were made for cardiovascular response to invasive procedure, post anaesthetic anxiety and delirium with help of Memorial Delirium Assessment scale (MDAS).

Midazolam reduced delirium to a greater level, but in comparison to control group and midazolam group, dexmedetomidine reduced delirium to a much greater level (p-value<0.001). Postoperative pain was less in Dexmedetomidine group (p-value< 0.001).

Dexmedetomidine reduced delirium caused by Ketamine when used as a premedication agent. It produced more haemodynamic stable patients. Postoperative analgesia was also better.