Morphine and postoperative rewarming in critically ill patients.

Area of Science:

• Anesthesiology
• Critical Care Medicine
• Pharmacology

Background:

• Perioperative stress responses can increase metabolic demand and myocardial workload.
• Hypothermia during surgery necessitates careful rewarming, which can exacerbate physiological stress.
• Morphine sulfate (MSO4) is known to attenuate stress responses.

Purpose of the Study:

• To evaluate the efficacy of morphine sulfate (MSO4) in mitigating perioperative stress in hypothermic critically ill patients.
• To assess the impact of MSO4 on metabolic demand and cardiovascular function during postoperative rewarming.

Main Methods:

• Two groups of critically ill patients with intraoperative hypothermia were studied.
• One group received routine medical management (control).
• The other group received intravenous morphine sulfate (MSO4) at 1 or 4 mg/kg, followed by an infusion of 0.2 or 0.5 mg/kg/hr.

Main Results:

• Morphine sulfate (MSO4) infusion significantly reduced metabolic rate and myocardial work during rewarming.
• Patients receiving MSO4 experienced longer rewarming times with reduced shivering and heat loss.
• Cardiovascular parameters including heart rate, mean arterial pressure, and rate-pressure product were preserved.

Conclusions:

• Morphine sulfate (MSO4) effectively suppresses perioperative metabolic demands and myocardial workload in critically ill patients.
• MSO4 administration aids in preserving cardiovascular function during the challenging rewarming phase.
• This suggests MSO4 is a valuable agent for managing stress in the perioperative period for this patient population.