The incidence of hyperglycemia in patients receiving TPN

Nutrition Research Newsletter, Oct, 2004

Hyperglycemia associated with insulin resistance has been linked to increased morbidity during hospital stays. There is evidence that controlling hyperglycemia during illness is associated with improved outcomes; and tightly controlled blood sugar levels have been shown to cause remarkable decreases in morbidity and mortality in the critically ill. Hyperglycemia is considered a major side effect of total parenteral nutrition (TPN). The use of TPN in most hospitalized patients is appropriately limited based on the increased risk of infectious complications and lack of clear benefit in patients with temporary gut failure. Investigations that compare standard hospital care to TPN patients with tightly controlled blood sugar control are yet to be performed.

The purpose of a pilot study was to determine if the medical records of hematopoietic stem cell transplant patients could be accurately reviewed for the primary variables of interest (TPN exposure, hyperglycemia, infection, in-hospital mortality) at two urban hospitals with stem cell transplant programs. A retrospective cohort investigation was conducted using the medical records of patients who had undergone hematopoietic stem cell transplant of a 6-month period. This population was selected because the exposure of interest (TPN) occurs in 50% to 60% of these patients, overall they are a well-nourished group with fairly similar baseline cardiac, pulmonary, renal, and hepatic function due to qualification for hematopoietic stem cell transplant. Additionally, they are immunocompromised and prone to infection; thus, influences on occurrence rates could be readily observable. Subjects were 18 years or older. Baseline clinical data (demographics, primary diagnosis, past medical or surgical history, transplant type) were collected from the physician's history. Laboratory reports were utilized to collect information regarding culture result (date of infection, source, and infectious agent) and daily blood draw values (white blood count, absolute neutrophil count, triglycerides, albumin, and glucose). Admission height and weight, as well as TPN dose, volume, and duration, were collected from the initial nutrition evaluation or from pharmacy records.

The primary outcome measure was hyperglycemia. Glucose was recorded one time per day. Hyperglycemic events were tallied as total number of days with blood sugar of 6.1 mmol/L or more. The secondary outcome measures were number and duration of infections and in-hospital mortality.

The subjects were found to have similar baseline demographic and clinical characteristics, with 63% receiving TPN during transplant. When standardized for time, TPN recipients at both institutions experienced significantly more hyperglycemia (P<.05) after TPN initiation. TPN patients also experienced 69% of all infections and 100% of repeat positive cultures. Additionally, significantly greater differences for TPN recipients were found for length of stay and daily charges than those who did not receive TPN. No differences were found for on-hospital mortality.

It is concluded that TPN is strongly associated with hyperglycemia, which may be linked to increased infections of longer duration in a profoundly immunocompromised group of patients who frequently receive TPN. Investigators feel that a larger study on this subject is warranted.

P. Sheean, C. Braunschweig, E. Rich. The incidence of hyperglycemia in hematopoietic stem cell transplant recipients receiving total parenteral nutrition: A pilot study. J Am Diet Assoc; 104:1352-1360 (September, 2004). [Correspondence: Patricia M. Sheean, MS, RD, University of Illinois at Chicago, Department of Human Nutrition, M/C 517 1919 West Taylor Street, Room 650, Chicago, IL 60612. E-mail: psheea1@uic.edu].