Medical Center

Skip to content. | Skip to navigation

Personal tools

Home > Clinical Nutrition Services > Inpatient Clinical Nutrition Services > Digestive Health > E-journal Club > march06.html


University of Virginia Nutrition Support
E-Journal Club
March 2006


We had a wonderful March traineeship, with real spring weather arriving mid-week, and Thai food for our night out.  This month our trainees hailed from Tennessee, Mississippi, and North Dakota.   

This month we reviewed two articles, one from JPEN and one from Archives of Surgery.

March Citations: 

  • Tiengou L-E, Gloro R, Pouzoulet J, et al. Semi-elemental formula or polymeric formula: is there a better choice for enteral nutrition in acute pancreatitis? Randomized comparative study. J Parenter Enteral Nutr 2006;30:1-5.


This study was a prospective, randomized, single blinded pilot study in 30 adult patients with acute pancreatitis comparing jejunal feeding with a semi-elemental formula (Peptamen) compared to a polymeric formula (Sondalis-Iso - similar to Nutren 1.0 in U.S.).  Patients were fed with nasojejunal tubes over 18 hours with a goal of 35 kcal and 1.5gm protein/ kg.  The primary endpoints were length of stay, weight loss and infectious complications.  The secondary endpoints were absorption (24-hour stool for steatorrhea/creatorrhea), GI tolerance (measured by # stools, abdominal pain, bloating, # days pts used class > II analgesia), C-reactive protein, serum amylase, serum albumin.

Major Results reported by authors:

They reported that tolerance to enteral feeding was good in both groups and not significantly different between formulas.  The authors also report that there were no significant differences in number of stools per 24 hours, steatorrhea or creatorrhea (fat or protein malabsorption).  The authors also report that the semi-elemental group had a shorter hospital stay (23 +/- 2 vs 27 +/- 1, p = 0.006) and less weight loss (1 +/- 1 vs 2 +/- 0, p = 0.01) compared to the polymeric group. 

Authors Conclusions:

The authors concluded that "nutrition with a semi-elemental formula supports the hypothesis of a more favorable clinical course than nutrition with a polymeric formula, but this conclusion needs to be established in larger, adequately powered clinical trials."


This study was randomized, but was not double-blind, therefore the physicians and bedside caregivers could have known which formula the patient was receiving, and thus open to unintentional bias.  Our group found it most interesting that there was no apparent difference in feeding tolerance or malabsorption between the formulas.  In addition, those factors that might reflect an exacerbation of pancreatic inflammation such as CRP (C-reactive protein) and pain score, were also the same between the two groups.

The authors concluded that the results suggest a superiority of semi-elemental feedings due to a trend towards shorter stay and less weight loss in the semi-elemental group.  However, in such small groups a 4 day difference in length of stay could represent an artifact of random chance.  The polymeric group had two more patients with infections than in the semi-elemental group, which was not a significant difference, but could account for a difference in length of stay. 

The only variable that was significantly different was weight change.  Our interpretation of the weight difference was that this is a classic case of something that is statistically significant, but has no clinical significance.  The difference in weight between the groups was 2.4lbs.  In the discussion section the authors suggests that a 2.4 lb weight difference between groups in one week might be due to an increase in energy expenditure in the polymeric group.  Our interpretation is that such a small difference in weight between the groups more likely explained by a random difference in hydration status in patients with pancreatitis or "hospital-scale misadventure."  In order to lose 2.4 lbs of body mass the polymeric group would be required to have a caloric expenditure of approx. 1200 calories per day more than the semi-elemental group.  A 2.5lbs weight difference between groups is clinically insignificant and is most likely a random difference in fluid balance.

Take home message: 

This study was small (only 30 patients), intended as a pilot, and the investigators do point out that larger studies are necessary.  Our interpretation of this study is that it supports the use of polymeric formulas because there was no suggestion of any increased pancreatic stimulation.  C-reactive protein (CRP is sensitive), amylase (for what that is worth), albumin (again, for what its worth) and pain were all the same ....there was NO evidence of increased inflammation in the polymeric group.  It also suggests that these patients were not very sick - particularly given that analgesics were required only a small # of days in both groups.

Our second study was:

  • Schuster R, Grewal N, Greaney GC, et al. Gum chewing reduces ileus after elective open sigmoid colectomy. Arch Surg 2006;141:174-176.


This was a prospective, randomized study of thirty-four patients undergoing elective open sigmoid resections for recurrent diverticulitis or cancer.  Thirty-four patients were randomized into 2 groups: a gum-chewing group (n = 17) or a control group (n = 17). The patients in the gum-chewing group chewed sugarless gum 3 times daily for 1 hour each time until discharge.

Major Results reported by authors:

All gum-chewing patients tolerated the gum. The first passage of flatus occurred on postoperative hour 65.4 in the gum-chewing group and on hour 80.2 in the control group (p = .05). The first bowel movement occurred on postoperative hour 63.2 in the gum-chewing group and on hour 89.4 in the control group (p= .04). The first feelings of hunger were felt on postoperative hour 63.5 in the gum-chewing group and on hour 72.8 in the control group (p = .27). There were no major complications in either group. The total length of hospital stay was shorter in the gum-chewing group (day 4.3) than in the control group (day 6.8), (p = .01).

Authors Conclusions:

Gum chewing speeds recovery after elective open sigmoid resection by stimulating bowel motility. Gum chewing is an inexpensive and helpful adjunct to postoperative care after colectomy.


This is an interesting study because it is such a low risk approach and is potentially quite cost-effective.  Although the title of the study suggests that gum-chewing reduced ileus, only one patient in the entire study (control group) actually developed an ileus.  However, several other groups have recently reported favorably on the "prokinetic" action of gum-chewing, the more rapid return of flatus, bowel movements and feelings of hunger, suggesting a more rapid return of bowel function.

HOWEVER, the authors do not report how many patients stuck their gum to the bottom of the bed tables after they were done chewing it. J

Take home message: 

The results of this, and the other recent studies on post-operative gum-chewing, suggest that gum chewing may be worthy of consideration in the small number of patients in whom it is not practical or safe to begin either a regular diet or enteral tube feeding.


Other News:

1) Check out the latest Practical Gastroenterology article at: http://www.uvadigestivehealth.org/ 
Scroll down to GI Nutrition on the far left column and click on link
Then scroll down to box with links within the nutrition site
Nutrition Articles in Practical Gastroenterology is in the left column.

Javorsky B, Maybee N, Padia SH, Dalkin A.  Vitamin D deficiency in gastrointestinal disease.   Practical Gastroenterology 2006; XXX(3):52.

2) Y'all might appreciate this article "Laparoscopic Roux-En-Y Gastric Bypass for Morbid Obesity" it includes a video of the procedure.  Click on the first link that says view article.  You may have to register with medscape to view it (registration is free).



Joe Krenitsky MS, RD
Carol Parrish RD, MS

PS - Please feel free to forward this on to friends and colleagues.  

PS - Please feel free to forward this on to friends and colleagues.