Elsevier

The Lancet

Volume 359, Issue 9320, 25 May 2002, Pages 1812-1818
The Lancet

Articles
Effect of salt and water balance on recovery of gastrointestinal function after elective colonic resection: a randomised controlled trial

https://doi.org/10.1016/S0140-6736(02)08711-1Get rights and content

Summary

Background

Low concentrations of albumin in serum and long gastric emptying times have been returned to normal in dogs by salt and water restriction, or a high protein intake. We aimed to determine the effect of salt and water balance on recovery of gastrointestinal function after elective colonic resection in human beings.

Methods

We randomly allocated ten patients to receive postoperative intravenous fluids in accordance present hospital practice (⩾3 L water and 154 mmol sodium per day) and ten to receive a restricted intake (⩽2 L water and 77 mmol sodium per day). All patients had no disease other than colonic cancer. The primary endpoint was solid and liquid-phase gastric emptying time, measured by dual isotope radionuclide scintigraphy on the fourth postoperative day. Secondary endpoints included time to first bowel movement and length of postoperative hospital stay. Analysis was by intention to treat.

Findings

Median solid and liquid phase gastric emptying times (T50) on the fourth postoperative day were significantly longer in the standard group than in the restricted group (175 vs 72·5 min, difference 56 [95% CI 12–132], p=0·028; and vs 73·5 min, 52 [9–95], p=0·017, respectively). Median passage of flatus was 1 day later (4 vs 3 days, 2 [1–2], p=0·001); median passage of stool 2·5 days later (6·5 vs 4 days, 3 [2–4], p=0·001); and median postoperative hospital stay 3 days longer (9 vs 6 days, 3 [1–8], p=0·001) in the standard group than in the restricted group. One patient in the restricted group developed hypokalaemia, whereas seven patients in the standard group had side-effects or complications (p=0·01).

Interpretation

Positive salt and water balance sufficient to cause a 3 kg weight gain after surgery delays return of gastrointestinal function and prolongs hospital stay in patients undergoing elective colonic resection.

Introduction

Clinical observations in patients referred to the clinical nutrition unit at the University Hospital, Nottingham, UK, for postoperative nutritional support have suggested that elimination of oedema resulted in an increase in the concentration of albumin in serum,1 and in some cases was associated with earlier return of gastrointestinal function, allowing oral or enteral rather than parenteral feeding (unpublished observations). Mecray and colleagues2 induced hypoalbuminaemia by giving dogs a combination of saline, plasmapheresis, and low protein intake, which resulted in a 6–7 fold increase in gastric emptying time. At necropsy, the investigators ascribed the increase in gastric emptying time to oedema in the stomach wall. Gastric emptying was restored to normal either by salt and water restriction or a high protein intake. Whether these changes were because of hypoalbuminaemia, positive sodium balance, or both is unclear. Since then, hypoproteinaemia has also been associated with extended gastric emptying, delayed small bowel transit, or postoperative ileus.3, 4, 5

Such changes in patients receiving crystalloid infusions after surgery are exacerbated by the patient's diminished ability to excrete an excess sodium and water load,6, 7, 8 although this effect is sometimes forgotten.9, 10, 11 An increase in postoperative complications and adverse outcomes have been associated with administration of excess sodium and water in the perioperative period.11, 12, 13, 14, 15, 16 The 1999 report of the UK National Confidential Enquiry into Perioperative Deaths has also identified errors in fluid and electrolyte management as a significant cause of death.17

We aimed to test whether the delayed gastric emptying after an operation described in dogs,2 could also be seen in human beings through a positive salt and water balance; and conversely whether restriction of postoperative saline infusion, aimed at achieving near zero salt and water balance, could result in earlier return of gastrointestinal function and better clinical outcome.

Section snippets

Patients

We did a prospective randomised controlled trial set in a university teaching hospital. Between August, 1999, and February, 2001, we approached adults undergoing elective hemicolectomies and sigmoidectomies for cancer at University Hospital, Nottingham, UK, for enrolment. We selected only patients who were undergoing hemicolectomy because such patients are a homogeneous group in which to compare the effects of the two different fluid regimens on salt and water balance and gastrointestinal

Results

Figure 1 shows the trial profile, and table 1 shows the preoperative demographic and biochemical profiles of patients. Median intraoperative blood loss was 275 mL (IQR 169–381) in the restricted group and 238 mL (175–325) in the standard group (p=0·79, Mann-Whitney U test). No patient received blood transfusion, and the total operating time was not more than 2 h in any patient. Although mean infusions of sodium and water for the standard and restricted groups, respectively, were similar during

Discussion

Our results in human beings accord with the original observations made in 1937 by Mecray and colleagues2 in dogs. They show that a modest positive salt and water balance causing a weight gain of 3 kg after elective colonic resection, is associated with delayed recovery of gastrointestinal function, increased complication rate, and extended hospital stay. We were unable to determine whether these effects were a result of fluid gain, hypoalbuminaemia, or both, since the two are inseparable even

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