dec04.html

University of Virginia Nutrition E-Journal Club

December 2004

We do not run the NS traineeship in December, but we did host a Nutrition Support Forum this month.  The nutrition support forum is a small group of nutrition support professionals from a number of area hospitals who meet for half a day to critique a couple journal articles, discuss case studies and share clinical ideas in an informal setting.  Gary Ecelbarger MS, RD, from Fairfax Hospital, started and continues to moderate our forum.  His wealth of knowledge, experience and sense of humor makes our forum great to attend ! This month we reviewed two articles:

Bullock TK, Waltrip TJ, Price SA, et al.  A retrospective study of nosocomial pneumonia in postoperative patients shows a higher mortality rate in patients receiving nasogastric tube feeding.  Am Surg 2004;70(9):822-826.

The first study that we reviewed, on nosocomial pneumonia in postoperative patients, was published in the September 2004 issue of The American Surgeon.

Summary:
The authors of this retrospective review look at he records of 1969 patients who had elective general, cardiac, and thoracic procedures over a 6-month period.  They reported on 77 patients who met the criteria for pneumonia, and recorded data on:

  • Preexisting comorbid conditions
  • The number of days and type of antibiotic used
  • Type of microbial flora
  • Number of ventilator days, and
  • Use of enteral nutrition. 

In the 77 patients who developed pneumonia, 41 received no enteral feeding, and 33 received enteral feeding.  In the small cohort of patients with pneumonia, the authors report that the mortality was significantly higher in those patients who were receiving enteral feeding (11 of 33 patients [30%]), than in those patients who did not receive enteral feeding (= 7 of 41 patients [17%]).

Evaluation: 
This is a retrospective survey with an unavoidable potential for selection bias; some factor may have influenced the decision to begin enteral feeding, which also affects outcome.  The groups (enteral vs. non-enteral) are similar in a number of factors, but there is no way to control for all possible variables in a retrospective trial.  The authors suggest that enteral feeding may have been responsible for the increased mortality in this sub-population.  However, the authors also reported that there were significantly more patients with a history of smoking in the non-enteral feeding group.  Does this mean that a history of smoking reduces the mortality from nosocomial pneumonia?  It simply illustrates that these two groups were different in more factors than just enteral feeding. 

Take home message: 
Associations found in retrospective trials do not imply causation, and should not be used as “evidence” for, or against, modes of therapy or feeding.  Associations from retrospective surveys should be used to justify prospective studies.  We agree with the authors final conclusions that prospective trials are necessary to address possible harmful effects of enteral feeding, and to weigh that against possible harmful effects of not providing adequate nutrition.

Mesejo A, Acosta JA, Ortega C. et al.  Comparison of a high-protein disease-specific enteral formula with a high-protein enteral formula in hyperglycemic critically ill patients.  Clin Nutr 2003;22:295-305. 

The second study that we discussed was from the October 2003 Clinical Nutrition.

Summary:
This study was a prospective, randomized single-blind study of a tube feeding marketed for enhanced glucose control, compared with a standard fiber-free tube feeding.  The experimental formula’s calorie breakdown was 40% CHO, 20% protein, 40% fat.  The control formula was 49% CHO, 22% protein, 29% fat. 

The study was conducted in 2 ICUs; inclusion criteria included adult patients with a history of DM or stress-induced hyperglycemia, who required enteral nutrition for 5 or more days.  All patients received 24-hour feedings with of calorie goal of 1.2 X REE (Harris-Benedict), and had glucose controlled between 100-200 mg/dl with an insulin-drip.  The primary endpoints were glycemic control (glucose between 100-200mg/dl) and insulin requirements/day.  The authors reported that the mean glucose level, AND the mean insulin requirements were significantly higher in the 24 patients that received the standard tube feeding, compared to the 26 patients who received the experimental formula.  The standard feeding group received an average of 30 units of insulin per day (range 21.5-57.1), with a mean capillary glucose of 216 +/- 56.7 mg/dl, while the experimental group received an average of 8.7 units of insulin/day (range 2.3-27.5), with a mean capillary glucose of 163 +/- 45.6 mg/dl.  There was no significant difference in outcomes between the two groups in terms of mortality, acquired infections, ICU length of stay, or days of mechanical ventilation.

Evaluation:
This was a prospective, randomized study, but it was not double-blind.  While a double-blind study is clearly desirable, this study did have the advantage that the primary outcomes were objective (serum glucose and units of insulin).  The groups were well matched, with no significant difference in terms of calories provided, severity of illness, corticosteroid treatment, or history of diabetes.  However, one drawback of this study is the relatively small group size.  With small group size it is difficult to rule out all random chance effects.  For instance, if one group had several patients who had a greater degree of insulin resistance, or insulin requirement prior to admission, this could alter the results.  In a larger trial, the random allocation of patients makes an unequal distribution of patients unlikely.  Another factor that may have influenced the results was the protocol for capillary glucose checks every 6 hours.  In our intensive care units, where glucose is checked hourly and insulin-drips are adjusted accordingly, it is unlikely that a formula change would affect the overall glucose control. 

Take home message: 
This is a solid study, with interesting results.  The group decided that it would be important to have it repeated with larger numbers, in a double-blind study, and see a cost-effectiveness evaluation before we could recommend routine use of a more expensive formula.

Other News:

University of Virginia Health System Proposed Propofol Protocol (by Sherrie Walker RD)

 

   Patients with a history of dyslipidemia will have Triglyceride (TG) levels checked 24 hours after initiation of Propofol if delivery exceeds 500 mL /day (= approx. 20mL/hour).  If TG > 400mg/dl, and high dose continues, levels to be rechecked again in 24 hours.

   Patients without a history of dyslipidemia will have TG levels checked 48 hours after initiation of Propofol if delivery exceeds 500 mL/day, or if delivery exceeds 50% of estimated Kcal needs for > 48 hours.

   If followed by one of the nutrition support teams (NST) and the TG level exceeds 400 mg/dl, the NST will discuss with the primary team.  TG levels will continue to be monitored every 48 hours if infusion continues.

 

Used with permission from the University of Virginia Health System Nutrition Support Traineeship Syllabus

The following was sent to us as “The Dali Lama’s Instructions for Life”… like all e-mail and internet sources you have to take that with a grain of salt (non peer-reviewed and such) but we liked it nonetheless…

  1. Take into account that great love and great achievements involve great risk.
  2. When you lose, don't lose the lesson.
  3. Follow the three Rs:
    Ø       Respect for self
    Ø       Respect for others and,
    Ø        Responsibility for all your actions.
  4. Remember that not getting what you want is sometimes a wonderful stroke of luck.
  5. Don't let a little dispute injure a great friendship.
  6. When you realize you've made a mistake, take immediate steps to correct it.
  7. Spend some time alone every day.
  8. Open your arms to change, but don't let go of your values.
  9. Remember that silence is sometimes the best answer.
  10. Live a good, honorable life.  Then when you get older and think back, you'll be able to enjoy it a second time
  11. A loving atmosphere in your home is the foundation for your life.
  12. In disagreements with loved ones, deal only with the current situation.  Don't bring up the past.
  13. Share your knowledge.  It's a way to achieve immortality.
  14. Be gentle with the earth.
  15. Once a year, go someplace you've never been before.
  16. Remember that the best relationship is one in which your love for each other exceeds your need for each other.
  17. Judge your success by what you had to give up in order to get it.
  18. Approach love and cooking with reckless abandon.

 

Peace, and Happy Holidays !!!!

From our teams to yours - Good Nutrition For All and to all a good year!

Joe Krenitsky MS, RD
Carol Parrish RD, MS
Theresa Fessler MS, RD, CNSD
Le Banh MS, RD, CNSD
Sherrie Walker RD
Nicole Waldron RD
Kate Willcutts MS, RD, CNSD
Amy Radigan RD, CNSD
Kelly O’Donnell MS, RD, CNSD

PS – Please feel free to send this on to friends and colleagues.