The objective of this study is to evaluate the effects of 'high' versus 'low' volume intraoperative fluid administration (Ringer Lactate, RL) on intra- and postoperative parameters, in obese patients undergoing laparoscopic bariatric surgery (i.e., gastric bypass), in order to establish evidence-based data for perioperative fluid management in this patient population. Based on their experience as well as several reports in the literature, the investigators hypothesized that a restrictive approach to intraoperative hydration will reduce the incidence of postoperative complications and the recovery time of gastrointestinal (GI) function, and shorten hospital stay.

Obesity, a chronic disease that is increasing in prevalence in adults, adolescents, and children, is now considered to be a global epidemic. The prevalence of obesity has increased markedly in the last two decades and it is now considered to be a global epidemic. In the US 65% of all adults are overweight or obese and 30% are obese. Surgery is the only effective treatment for morbid obesity, and open Roux-en-Y gastric bypass (RYGB) has become the procedure of choice for these patients.

Several studies on perioperative fluid management have reported that 'high volume' regimens may result in overhydration having deleterious effects on cardiac and pulmonary function, recovery of GI motility, tissue oxygenation, wound healing and coagulation. Most reported randomized trials suggest that perioperative fluid management has evolved to a more restricted regimen. Specifically, restricted fluid volumes applied during bariatric procedures have been shown to reduce perioperative complications (pulmonary dysfunction, hypoxia, nausea and vomiting), thereby decrease the prevalence of morbidity and mortality associated with such procedures.

We wished to evaluate in a prospective randomized study the impact of fluid management on perioperative parameters in patients undergoing a variety of laparoscopic bariatric procedures: Roux-Y Gastric Bypass (LRYGB), Biliopancreatic Diversion with Duodenal Switch (LDS), or Sleeve Gastrectomy (LSG).

Patients were randomly allocated to one of two groups receiving either 4 ml/kg•hr or 10 ml/kg•hr of RL solution throughout the intra-operative period.

The primary endpoints of the study included: mortality rate and incidence of postoperative complications, during primary hospitalization. Readmission rate to the hospital within 30 days of surgery was another primary endpoint. The secondary endpoints included time till the patient resumed drinking and consuming soft food, length of hospital stay, differences in hematocrit, creatinine concentrations and oxygen saturation in the first and third postoperative days and with discharge, and the number of patients receiving transfusion of blood and blood products.

Inclusion Criteria:

• Adult patients ( >18 years) with an American Society of Anesthesiology physical status of I-III who were presenting for laparoscopic bariatric surgery, were prospectively studied.

• Patients were considered eligible if they had a BMI > 40, or > 35 and at least one comorbid condition and were scheduled to undergo one of the following laparoscopic operations:

  • Roux-Y Gastric Bypass (LRYGB)
  • Biliopancreatic Diversion with Duodenal Switch (LDS), or
  • Sleeve Gastrectomy (LSG).

Exclusion Criteria:

• Patients aged younger than 18 years.
• Patients with renal dysfunction (creatinine > 50% upper limit of normal value).
• Congestive heart failure.