ABSTRACT
OBJECTIVES: This study in swine assessed BIS stability in response to decreases and increases in cardiac output under two propofol/remifentanil dosage combinations, both producing the same depth of surgical anaesthesia. METHODS: Eight anaesthetized-paralyzed ventilated adult swine were studied using a random-order cross-over design. Four received a P low/R high combination (P, 8.4+/-0.9 mg/kg/h; and R, 0.54+/-0.02 microg/kg/min) and then a P high/R low combination (P, 26.7+/-2.1mg/kg/h; and R, 0.34+/-0.01 microg/kg/min). The other four had these two combinations in the reverse order. Under each P/R combination, and after a 60-minutes steady state, a 15-minute stable cardiac tamponade was induced by intrapericardial gelatine infusion. Then, after returning to pre tamponade condition, a 15 minutes period with dobutamine was allowed. RESULTS: Tamponade induced falls in average mean arterial pressure (MAP) (from 79+/-18 to 47+/-9 mm Hg; p<0.05) and cardiac output (Qc) (from 1.90+/-0.46 l/min to 1.20+/-0.38 l/min, p<0.05). Conversely, dobutamine increased both MAP and Qc (p<0.05). During each type of hemodynamic challenges, changes in anaesthesia depth as assessed by BIS differed dramatically between the two drug combinations, despite observing the same percent change in P and R effect-site concentration. With P high/R low and tamponade, BIS fell from 65+/-5 to 29+/-10 (p<0.05); dobutamine produced opposite effects. With P low/R high, in contrast, BIS was not influenced by either of the hemodynamic challenges. CONCLUSION: Conversely to a high propofol/low remifentanil combination, a low propofol/high remifentanil combination allows constant anaesthetic depth in the face of haemodynamic challenges.
Subject(s)
Analgesics, Opioid/pharmacology , Cardiac Tamponade/chemically induced , Cardiac Tamponade/physiopathology , Cardiotonic Agents/pharmacology , Dobutamine/pharmacology , Electroencephalography/drug effects , Hypnotics and Sedatives/pharmacology , Anesthesia, Intravenous , Anesthetics, Intravenous/pharmacology , Animals , Blood Pressure/drug effects , Cardiac Output/drug effects , Drug Combinations , Monitoring, Intraoperative , Piperidines/pharmacology , Propofol/pharmacology , Remifentanil , SwineABSTRACT
Arsenic (As) intoxication is nowadays extremely rare. Two cases of acute and chronic As criminal poisoning leading to death of a couple of retired people, are reported. Clinical presentation was simulating a gastro-enteritidis with fast evolution to refractory shock. Toxicological analysis confirmed this diagnostic, with respectively blood As concentrations at 579 and 21 765 microg/l for our two patients.
