Apr07.html

University of Virginia Nutrition Support
E-Journal Club
April 2007

 

Greetings,

We have just concluded our April traineeship and, as always at the end of the week, we are sad to see such wonderful professionals leave UVA!  We enjoyed our two trainees from Green Bay, Wisconsin and the other two from Boulder, Colorado and Largo, Maryland.  This month our traineeship coincided with our semi-annual Nutrition Support Forum, where nutrition support professionals gather for ½ day of journal review, case studies, and informal sharing of ideas, experiences and clinical practice.

April 2007 NST Forum

Every now and again we feel obliged to restate that our ejournal club is meant as a brief summary, and there is no way to mention ALL of the worthwhile aspects of each study and still keep this readable.  So (as always) we encourage everyone to read the full study, and feel free to contact us with questions or if you feel there are important additions or corrections.

 

April Citations: 

  1.  Davis K, Kinn T, et al. Nutrition Gain Versus Financial Gain: The Role of Metabolic Carts in the Surgical ICU. Journal of Trauma Injury, Infection, and Critical Care 2006; 61(6):1436-1440.
  2.  Eckerwall G, Axelsson J, et al. Early Nasogastric Feeding in Predicted Severe Acute Pancreatitis: A Clinical, Randomized Study. Annals of Surgery 2006;244(6): 959-967.

 


 1) Eckerwall, G, Axelsson, J, et al. Early Nasogastric Feeding in Predicted Severe Acute Pancreatitis: A Clinical, Randomized Study. Annals of Surgery 2006;244(6): 959-967.

 

Summary: 

This was a prospective, randomized, unblinded study of 50 patients predicted to have severe acute pancreatitis comparing early nasogastric enteral nutrition (EN) (n=24) with parenteral nutrition (PN) (n=26). The nutrition goal was to provide 25 calories/kg within 72 hours. 

The primary endpoint of the study was intestinal permeability measured by the excretion of polyethylene glycol in the urine.  The researchers also measured antiendotoxin core antibodies for immunoglobulin M (indirect marker for intestinal permeability) and IL-6, IL-8 and C-reactive protein (markers of inflammatory response).  Frequency of complications, hyperglycemia, GI symptoms, and abdominal pain were also reported.

Inclusion Criteria :

Patients admitted with a clinical diagnosis of acute pancreatitis were considered for inclusion.  Inclusion criteria were abdominal pain, amylase 3X upper limit of normal, onset of abdominal pain with 48 hours, and one or more of the following: APACHE II score > 8, CRP > 150, peripancreatic fluid collection on CT.  Exclusion criteria were pancreatitis due to trauma or cancer, or a history of any of the following: inflammatory bowel disease, stoma, short bowel, chronic pancreatitis.

Major Results reported by authors:

The researchers reported no significant difference between the EN and PN groups in the major endpoint of intestinal permeability as measured by the appearance of polyethylene glycol in the urine.  There was also no significant difference in antiendotoxin core antibodies, or markers of inflammation between the groups after the baseline measurements.

The incidence of hyperglycemia was significantly greater in the PN group compared to the EN group (21 of 26 versus 7 of 23 respectively, p < 0.001).

Total complications were significantly greater in the enteral group (10 of 26 [40%] in PN and 16 0f 23 [70%] in EN).  Pulmonary complications were also significantly greater in the EN group.

Author's Conclusions:

The author's conclusions were that nasogastric early EN was feasible and resulted in better control of blood glucose levels, although the overall early complication rate was higher in the EN group.  No beneficial effects on intestinal permeability or the inflammatory response were seen by EN treatment.

Evaluation:

This study has a number of critical limitations.  The first is that although the investigators intended to study severe pancreatitis, only 46% of the ultimate study population had severe pancreatitis, and 54% of the subjects had mild pancreatitis.

Another important point is that the study did not have adequate numbers of subjects for adequate comparison of outcomes - the power calculations were based on the number of patients necessary to detect changes in intestinal permeability.  A meaningful analysis of complications and outcomes is not possible in the very small number of patients who actually had severe pancreatitis.

Considering the small number of patients that had severe pancreatitis, the finding of significantly more complications in the EN group, despite the greater hyperglycemia in the PN group, could be interpreted as a sign that gastric feeding should be avoided in pancreatitis.  The authors suggested that, "it is unlikely that the route of nutrition could have an impact," although several of the most common complications during the first 3 days of the study (pleural effusions and peripancreatic fluid collections) are precisely the nature of complications that one would expect during an exacerbation of acute pancreatitis.

Finally, the median blood glucose levels were 16 mmol/L (290 mg%) when insulin therapy was initiated, yet the authors also state, "not all patients with hyperglycemia received insulin."

Take home message: 

Our conclusion was that this study provides further evidence that gastric feeding should be avoided in severe pancreatitis until a larger study is conducted that has adequate power AND adequate methodology - e.g. compares gastric feeding to jejunal feeding with a jejunal tube properly positioned beyond the ligament of Treitz.

 


2) Davis, K, Kinn, T, et al. Nutrition Gain Versus Financial Gain: The Role of Metabolic Carts in the Surgical ICU. J Trauma Injury Infect Crit Care 2006;1436-1440.

 

Summary: 

This was a study of consecutive metabolic cart measurements that were prospectively obtained on 59 critically ill surgery and trauma patients, and compared with predicted values as determined by the Harris-Benedict equation adjusted with a factor of 1.5, and a weight based calculation at 30 kcal/kg adjusted body weight.

 

Inclusion Criteria:

The researchers included mechanically ventilated surgery and trauma patients who required mechanical ventilation for more that 72 hours.

Patients were excluded if they required more than 60% FiO2, had surgery within 24 hours, or excessive chest or endotracheal tube leaks, concurrent hemodialysis, significant activity within 30 minutes of the study, or an inability to attain a steady state during the test.

 

Major Results reported by authors:

A total of 106 metabolic cart measurements were obtained, with 37% of the population having 2 or more measurements.  The researchers reported that there was no statistically significant difference between the metabolic cart results and the predicted REE as calculated by the Harris-Benedict equation adjusted with a factor of 1.5; nor was there a difference between metabolic cart results as compared with a weight based calculation at 30 kcal/kg ideal body weight.

 

Author's Conclusions:

Either 30 kcal/kg adjusted body weight or the resting energy expenditure calculated from the Harris-Benedict equation multiplied by 1.5 adequately predicts the nutritional requirements of critically ill surgery and trauma patients.

The addition of metabolic cart data does not provide any additional information in the determination of caloric needs in the critically ill and injured patient.

 

Evaluation:

This study has a major flaw in that it examined only the average of all of the patient's calorie measurements (and calculations) put together, and reported no analysis of the error in prediction equations, or of possible changes in calorie expenditure week to week in individual patients.  It is possible that a number of individual patients would have been significantly underfed, or overfed with the use of the prediction equations, but there is no way know that because all of the predicted calculations and measured calorie expenditures were averaged together.

 

Take home message:

The use of average values in reporting the results severely limits the usefulness of this study, and the does not exclude the possibility that individual patients may receive excessive or inadequate calories by the use of the prediction equations listed.

 


Other News:

1)     Our first Weekend Warrior Mini-Nutrition Support Traineeship was a great success!  Check out our website for the dates of our next one:

http://www.healthsystem.virginia.edudh/traineeship.html.     

2)     Check out the latest Practical Gastroenterology articles/info at:

http://www.uvadigestivehealth.org/ 

Scroll down to GI Nutrition on the far left column and click on link
This leads to a pull down menu with links within the GI nutrition site including the Nutrition Articles in Practical Gastroenterology.  April's articles are:

1) Burns SM.  Prevention of Aspiration Pneumonia in the Enterally Fed Critically Ill, Ventilated Patient: It Takes A Village!  Practical Gastroenterology 2007;XXXI(4):63.

2) Cureton P.  The Gluten-free Diet: Can Your Patient Afford It?  Practical Gastroenterology 2007;XXXI(4):75.

 

Joe Krenitsky MS, RD

Carol Parrish RD, MS

PS - Please feel free to forward this on to friends and colleague