Bowel preparation with oral polyethylene glycol electrolyte solution vs. no preparation in elective open colorectal surgery: prospective, randomized study.

PURPOSE: Efficient mechanical bowel preparation has been regarded as essential in preventing postoperative complications of colorectal surgery, but the necessity of bowel cleansing has been disputed recently. The aim of this study was to evaluate the outcome of elective colorectal surgery in patients with or without bowel preparation. METHODS: Altogether, 267 consecutive adult patients admitted for elective open colorectal surgery were randomly assigned either to the bowel preparation group with oral polyethylene glycol electrolyte solution (138 patients) or no preparation group (129 patients). Patients who were unable to drink polyethylene glycol electrolyte solution, those who had had bowel preparation within the previous week, and patients not needing opening of the bowel were excluded. Routine colorectal surgery was undertaken, and infectious and other complications were registered daily. Late complications were checked up one to two months after surgery. RESULTS: No deaths were recorded, and 76 percent of the patients in the polyethylene glycol electrolyte solution group and 81 percent in the unprepared group recovered without complication. Anastomotic leaks occurred in 4 percent of the polyethylene glycol electrolyte solution patients and in 2 percent of the other cases, and other surgical site infections occurred in 6 and 5 percent, respectively. None of the differences was statistically significant. There was no difference in restoration of bowel function. The median postoperative stay was eight days in both groups. CONCLUSIONS: Preoperative bowel preparation seems to offer no benefit in elective open colorectal surgery.

The adverse hemodynamic effects of anesthesia, head-up tilt, and carbon dioxide pneumoperitoneum during laparoscopic cholecystectomy.

BACKGROUND: The increased intra-abdominal pressure during pneumoperitoneum, together with the head-up tilt used in upper abdominal laparoscopies, would be expected to decrease venous return to the heart. The goal of our study was to determine whether laparoscopy impairs cardiac performance when preventive measures to improve venous return are taken, and to analyze the effects of positioning, anesthesia, and increased intra-abdominal pressure. METHODS: Using invasive monitoring, hemodynamic changes were investigated in 15 ASA class I or II patients under isoflurane-fentanyl anesthesia during laparoscopic cholecystectomy. Before laparoscopy, the patients received an intravenous (IV) infusion of colloid solution if cardiac filling pressures were low, and their legs were wrapped from toes to groin with elastic bandages. Measurements were taken while the patients were awake in the supine (baseline) and head-up tilt (15-20 degrees) positions, and after the induction of anesthesia in the same positions. Measurements were repeated at regular intervals during laparoscopy (intra-abdominal pressure at 13-16 mm Hg), after deflation of the gas, and in the recovery room. RESULTS: With the passive head-up tilt in awake and anesthetized patients, the cardiac index (CI), stroke index (SI), central venous pressure (CVP), and pulmonary capillary wedge pressure (PCWP) decreased, and systemic vascular resistance increased. With the patient under anesthesia, SI decreased, but CI did not change significantly as a result of the compensatory increase in heart rate. Carbon dioxide (CO2) insufflation at the start of laparoscopy produced increases in CVP and PCWP as well as mean systemic and mean pulmonary arterial pressures without changes in CI or SI. Toward the end of the laparoscopy, CI decreased by 15%. The hemodynamic values returned to nearly prelaparoscopic levels after deflation of the gas, and CI was elevated during the recovery period, whereas systemic vascular resistance was decreased in comparison with the baseline. CONCLUSIONS: By correcting relative dehydration and preventing the pooling of blood, CI decreased less than 20% during pneumoperitoneum as compared with the baseline awake level. The head-up positioning accounts for many of the adverse effects in hemodynamics during laparoscopic cholecystectomy.