In the postoperative recovery period after abdominal surgery, should patients be allowed to choose their own diet, or should their food intake be limited until the return of digestive function? The authors conducted a randomized trial comparing these divergent approaches in a group of patients undergoing either colectomy or abdominal vascular surgery. For patients in the early feeding group, there was minimal difference in any of the specified outcome measures, except that consumption of a normal diet was delayed in the restricted food intake group.
This study was selected from Medscape Best Evidence, which uses the McMaster Online Rating of Evidence System. Of a possible top score of 7, this study was ranked as 5 for newsworthiness and 6 for relevance by clinicians who used this system.
Commentary
Paraphrasing Shakespeare, "To feed or not to feed," is the research question posed by the authors of this randomized clinical trial. The traditional post-gastrointestinal surgical approach during which an intestinal anastomosis has been formed is to withhold solid food for several days ("nil by mouth"). A nasogastric tube is inserted to decompress the stomach and intravenous fluids are administered. As gastric dysmotility resolves, postoperative feeding is initiated with gradually increased amounts of fluid. The patient is allowed solid foods only when there is evidence (passage of flatus or a bowel movement) that postoperative ileus has subsided.
But is dietary restriction really necessary, or can the patient be allowed to chose when and what to eat? To answer this question, the authors recruited 128 patients undergoing surgery at 2 teaching hospitals and 1 nonteaching hospital in The Netherlands. These patients were scheduled to undergo major abdominal surgeries -- either colon resection or abdominal vascular surgery. They randomly assigned patients to 1 of 2 groups:
Patients followed a conventional postoperative dietary approach (increasing amounts of liquids for the first 3 days, then an easily digested diet on day 4, followed by a normal diet on day 5); or
Patients were allowed to choose what they wanted to eat and when they wanted to eat it.
The main endpoint was the need to reinsert a nasogastric tube. Secondary endpoints included time until patient consumed a normal diet, length of hospital stay, and postoperative complications. The study is unique in that it includes pain score and quality-of-life information. The authors attempted to measure pain using a10-point scale and quality of life with a standard 36-item questionnaire (SF-36) and a 20-item scale designed to measure fatigue.
The 2 groups were similar with respect to proportion of males and females, age, body mass index, type of anesthesia, type of surgery, and comorbidities. The only observed difference was in measured blood loss, which was greater in the group assigned to the conventional dietary approach. However in the analysis, the authors adjusted for this difference, so it shouldn't have biased the results.
What were the findings? In nearly every outcome measure, the 2 groups were statistically similar, including time to passage of flatus or defecation, need to reinsert a nasogastric tube, and length of hospital stay. Neither the pain nor quality-of-life parameter seemed to be affected by early feeding. It is particularly reassuring that postoperative mortality (total number of patients = 5) and morbidity did not differ between the 2 groups. The only significant difference was in the time to tolerating solid food -- 2 days for patients on the self-selected dietary regime and 5 days for patients assigned to the conventional postoperative diet.
Because there were no differences in most outcomes between the 2 dietary approaches, can we conclude that they are equivalent? Should we allow patients to choose their own diets? Based on this study, the answer is a qualified "Maybe."
What are the study's weaknesses? One of the main concerns is that this was a small study; in a larger study, some differences between the 2 groups may have appeared. For example, 10% of patients in the conventional group required reinsertion of a nasogastric tube compared to 20% of the patients in the "eat whatever you feel like" group. This difference was not statistically significant, but if the sample size had been larger -- say 200 patients in each group, perhaps the difference might have reached significance.
Another drawback of the study is that it did not record or measure what the patients on the ad lib diet actually ingested. For example, they may have initially consumed only liquids, but resumed a normal diet only a day or 2 earlier than the control group. Another possibility is that those patients who required reinsertion of a nasogastric tube consumed solid foods immediately after surgery, whereas the subjects not requiring reintubation were slower to resume a normal diet. In any case, it is unfortunate that the study did not include this information.
How does this study compare to similar reports? Since 2000, there have been several studies looking at the issue of early feeding after abdominal surgery. Lewis and coworkers published a meta-analysis in 2001 looking at early feeding vs a restricted diet. Based on 11 studies, they concluded that there was no benefit in adhering to a restricted diet.[1] They pointed out that postlaparotomy dysmotility predominantly affects the stomach and colon and that the small bowel recovers normal function between 4 and 8 hours,[2] with feeding tolerated and food absorbed within 24 hours.[3,4] Although early feeding was associated with an increased risk of vomiting (P ≥ .05), the meta-analysis did not appear to find any other clear advantage in keeping patients nil by mouth after elective gastrointestinal resection. Early feeding was associated with reduced length of stay, reduction in infections, and possible reduced risk for dehiscence.[1] The authors of an accompanying editorial wondered whether the benefits of early oral feeding differ by preoperative nutritional status.[5] Does this policy afford the greatest benefit to malnourished patients?
Andersen and colleagues[6] conducted a systematic 2006 review of 13 randomized trials totaling 1173 patients undergoing gastrointestinal surgery. There were no significant differences between restricted and ad lib postoperative diets, but the findings also suggested that there was no advantage to dietary restriction. Also, although not reaching statistical significance, the direction of effect in the analysis also indicated that earlier feeding may reduce the risk of postoperative complications.
In 2007, Charoenkwan and colleagues[7] performed another systematic review of postoperative diets in patients undergoing abdominal gynecologic surgery. They also found that early feeding was safe, but, similar to other reports, associated with increased nausea. There appeared to be no significant shortening of time to first passage of flatus or time to first bowel movement. They concluded that the decision to initiate early oral feeding should be made on an individual basis, taking into consideration cost-effectiveness, patient satisfaction, and other physiologic changes.[7]
In a 2006 study of "fast-track" rehabilitation programs in colonic surgery, the authors used a postoperative diet consisting of tea and soup, which gave the patients optimistic signals that they were in good health and would leave the hospital shortly. The authors concluded that early feeding, then, also may have positive psychological effects that can aid recovery. In any case, the authors cited studies showing that protein-enriched, high-caloric nutritional supplements (1.5 kcal and
0.05 g protein/mL) significantly decrease postoperative complications and they recommended that they be administered immediately after surgery and continued until the patient starts eating and drinking normally.[8,9]
In summary, the study under discussion here adds to information available from several prior studies indicating that early oral feeding is safe and does not increase morbidity or mortality. Because time to resumption of a normal diet is significantly shorter hospital stay may be shortened.
Perhaps the best policy might be an "in between" approach. Patients could be told: "After your operation you can eat and drink whatever appeals to you, but we don't advise resuming a normal diet or eating a lot of solid foods for the first 24-36 hours." Such a policy might avoid the increased nausea and reduce the need for reinsertion of a nasogastric
|
