Society of Cardiovascular Anesthesiologists

A Randomized Comparison of Effects of Intravenous Fluid Restriction on Postoperative Complications: Comparison of Two Perioperative Fluid Regimens - A Randomized Assessor-Blinded Multicenter Trial.

Brandstrup B, Tonnesen H, Beier-Holgersen R, et al. Ann Surg 2003; 238: 641-648.

Reviewer: Michael H. Wall, MD
University of Texas
Southwestern Medical Center at Dallas
Dallas, TX

The objective of this fascinating study was to evaluate the effects of restricted (R) intravenous (IV) fluid versus standard (S) intravenous fluid resuscitation for patients undergoing elective colorectal resection. This prospective randomized observer-blinded trial involving 172 patients was conducted in 8 Danish hospitals. ASA I-III patients undergoing elective colorectal resection were eligible. Patients with diabetes mellitus, renal insufficiency, inflammatory bowel disease or disseminated cancer were excluded. All patients had combined general and thoracic epidural anesthesia, and the epidural was used post-operatively.

The S regimen received 500 mL Hydroxyethyl starch 6% in normal saline (6% HAES) prior to induction and "third space" losses were replaced with normal saline (NS). These were omitted from the (R) group. Blood loss was replaced 1:1 with 6% HAES in the R group, and was replaced 3:1 with NS in the S group. Blood loss %gt;500 mL in the S group was replaced 1:1 with 6% HAES. For blood loss %gt;1500 transfusion was used to maintain the hematocrit in the range of 25-35%. Post-operatively, patients in both groups were enterally fed via a feeding tube 500 mL the day of operation and 1000 mL/day following. Patients in the S group received additional IV fluid. Patients in the R group received 1 L glucose 5% on the first post-operative day. Further fluid therapy in the R group was guided by weight; if the post-operative weight had increased by more that 1 kg, furosemide was given; if the weight decreased additional fluid was given. Patients requiring re-operation or intensive care were removed from the study. Mean arterial blood pressure was maintained %gt;60 mmHg in both groups with ephedrine and/or dopamine in both groups.

There were no significant differences in baseline characteristics (including cardiovascular or pulmonary disease, APACHE2 score or ASA status) between groups. Surgical time (3 hours), blood loss (400 mL vs 500 mL, R vs S) and transfusions (28% in both groups) were not different between groups. On the day of surgery the S group received significantly more fluid than the R group [5388 mL (range 2700-11083) vs 2730 mL (range 1100-8050); p <0.0005]. There was also a significant difference on post-operative day #1 (POD #1) (S 1500 mL vs R 500 mL, p = 0.003). Further, patients in the S group showed significant increases in body weight on POD #1-6. At a median follow-up of 34 days, there were significantly more total complications in the S vs R group (51% vs 33%). There were significantly more major, minor, tissue-healing and cardiopulmonary complications in the S group. There was no significant difference in mortality between the groups (4.7% vs 0%; p = 0.12 S vs R respectively). There was also a significant dose-response relationship between volume administered and/or weight gain and complications. Finally, although the urine output (UOP) was significantly lower in the R group, on the day of surgery, there was no difference in the UOP on POD #1-6.

This extremely well done randomized clinical trial shows that restricting IV fluid to maintain body weight significantly reduced complications following elective surgery in patients without diabetes or renal insufficiency. Applying these results to patients with diabetes or renal insufficiency undergoing other types of surgery of longer duration is a provocative thought that should be tested in future clinical trials.

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