Effect of vitamin C on morphine use after laparoscopic cholecystectomy: a randomized controlled trial.

Purpose: We designed a randomized double-blind placebo-controlled trial to assess the role of a single prophylactic dose of vitamin C (2 g) po in reducing the consumption of opioids postoperatively in patients undergoing laparoscopic cholecystectomy.

Methods: Eighty adult patients were allocated to receive 2 g vitamin C po or placebo approximately one hour prior to induction of anesthesia. Following laparoscopic cholecystectomy, patients received morphine patient-controlled analgesia for 24 hr.

End-tidal CO2 for prediction of cardiac output following weaning from cardiopulmonary bypass.

This prospective study included 32 patients undergoing cardiopulmonary bypass (CPB) for elective coronary artery bypass grafting correlates the respiratory end-tidal CO2 (ETCO2) during partial separation from CPB with cardiac output (CO) following weaning from CPB. After induction of general anesthesia, a pulmonary artery catheter was inserted for measurement of cardiac output by thermodilution. Patients were monitored using a 5-lead ECG, pulse oximeter, invasive blood pressure monitoring, rectal temperature probe, and end-tidal capnography.