Ketamine is one of the commonest abusing agents in Hong Kong. Our study aims to identify their clinical pattern of presentations to emergency departments. Method: This is a retrospective survey study. The studied group was ketamine abusers being referred to us from a source out of emergency department (ED). Control group was randomly selected from patients attending our ED. The electronic records of the ketamine abusers and the controls in the past 3 years (1st April 2004-31st March 2007) were reviewed and analysed. Result: Total 91 subjects (48 in ketamine group, 43 in control group) were included. The mean age of ketamine abusers and control group are 21 and 22.2 year-old respectively. Most of them (97.9%) did not declare their background of ketamine abuse. The mean 3-year attendance rate for the ketamine group was 2.38 and for control group was 0.91, with a difference of 1.47 (95% CI 0.54-2.41, p=0.003). Most of their illnesses were diagnosed as epigastric pain (25%), followed by upper respiratory tract infection (18.8%), head injury (10.4%) and urinary tract infection (10.4%). Significantly higher number of ketamine abusers presented with epigastric pain compared with control group (odds ratio 143, p<0.001). Conclusion: Most teenage ketamine abusers do not declare their background of drug abuse when they present to emergency departments. They tend to have a higher frequency of attendances. Most of their presenting problems are related to gastrointestinal system.

A 57-year-old woman presented with abdominal distension and vomiting two days after overdosing an unknown amount of sustained-release nifedipine tablets. She had refractory shock requiring calcium chloride, glucagon, insulin-glucose and multiple high-dose inotropic agent infusions in the intensive care unit. Her abdominal computed tomography showed features of bowel ischaemia and exploratory laporotomy reviewed non-salvageable massive bowel ischaemia. She finally succumbed after 22 days of hospital treatment. This case illustrates the importance of awareness of this potentially fatal complication of calcium channel blocker overdose, requiring early recognition and intervention. (Hong Kong j.emerg.med. 2010;17:360-363) 57 − 22