Changes in cardiorespiratory function during gastric lavage for drug overdose.

Cardiorespiratory function in 42 patients admitted to the Regional Poisoning Treatment Centre, Edinburgh who underwent gastric lavage for self poisoning, was studied using an electrocardiograph and an ear oximeter. Mean pulse rate rose from 92 to 121 beats per min and the mean partial pressure of oxygen fell from 95 to 80 mmHg during lavage (P less than 0.001). These changes were significantly greater in conscious than unconscious patients, in smokers than in non-smokers and most marked in male smokers aged 45 or older. No sex or age differences were noted. Electrocardiograph changes were noted in 41% of patients, including potentially serious changes in 2 patients. The indications for gastric lavage should probably be reviewed particularly in conscious older patients who smoke and due consideration given to induced emesis and ingestion of activated charcoal as alternatives.