Slowing of the heart during hypotension in major abdominal surgery.
Heart rate (HR) and mean arterial blood pressure (MBP) were studied during abdomino-perineal resections of the rectum under neurolept anesthesia in order to observe HR deviations due to hypovolemic hypotension. Of the 65 patients followed, 18 developed a systolic BP under 100 mmHg. Their blood loss (37 +/- 9 ml/kg, mean +/- s.e. mean) was higher than that of the normotensive control group (20 +/- 2 ml/kg, P less than 0.01), the urine production lower (8 +/- 1 versus 10 +/- 3 ml/kg, P less than 0.01) and blood transfusions amounted to 40 +/- 8 versus 24 +/- 2 ml/kg (P less than 0.01). In the hypotensive patients a decrease in MBP from 108 +/- 3 to 94 +/- 3 mmHg was accompanied by a simultaneous increase in HR from 81 +/- 3 to 91 +/- 3 beats/min (P less than 0.05). However, during the hypotensive incident where the MBP averaged 69 +/- 4 mmHg, HR decreased temporarily to 75 +/- 3 beats/min (P less than 0.001). After MBP was restored to 94 +/- 3 mmHg using volume repletion, HR increased to 95 +/- 3 beats/min (P less than 0.001). The results demonstrated a temporary slowing of HR in anesthetized, bleeding and hypotensive patients.
D000368:Aged; D001285:Atropine / Q000627:therapeutic use; D001794:Blood Pressure; D001919:Bradycardia / Q000503:physiopathology*; D005260:Female; D006470:Hemorrhage / Q000503:physiopathology*; D006801:Humans; D007022:Hypotension / Q000188:drug therapy / Q000503:physiopathology*; D007431:Intraoperative Complications / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009458:Neuroleptanalgesia; D012007:Rectum / Q000601:surgery*; D014630:Vagus Nerve / Q000503:physiopathology
D001285:Atropine