Immediate postoperative enteral feeding results in impaired respiratory mechanics and decreased mobility.

OBJECTIVE: The authors set out to determine whether immediate enteral feeding minimizes early postoperative decreases in handgrip and respiratory muscle strength. SUMMARY BACKGROUND DATA: Muscle strength decreases considerably after major surgical procedures. Enteral feeding has been shown to restore strength rapidly in other clinical settings. METHODS: A randomized, controlled, nonblinded clinical trial was conducted in patients undergoing esophagectomy or pancreatoduodenectomy who received immediate postoperative enteral feeding via jejunostomy (fed, n = 13), or no enteral feeding during the first 6 postoperative days (unfed, n = 15). Handgrip strength, vital capacity, forced expiratory volume in one second (FEV1), and maximal inspiratory pressure (MIP) were measured before surgery and on postoperative days 2, 4, and 6. Fatigue and vigor were evaluated before surgery and on postoperative day 6. Mobility was assessed daily after surgery using a standardized descriptive scale. Postoperative urine biochemistry was evaluated in daily 24-hour collections. RESULTS: Postoperative vital capacity (p < 0.05) and FEV1 (p = 0.07) were consistently lower (18%-29%) in the fed group than in the unfed group, whereas grip strength and maximal inspiratory pressure were not significantly different. Postoperative mobility also was lower in the fed patients (p < 0.05) and tended to recover less rapidly (p = 0.07). Fatigue increased and vigor decreased after surgery (both p < or = 0.001), but changes were similar in the fed and unfed groups. Intensive care unit and postoperative hospital stay did not differ between groups. CONCLUSIONS: Immediate postoperative jejunal feeding was associated with impaired respiratory mechanics and postoperative mobility and did not influence the loss of muscle strength or the increase in fatigue, which occurred after major surgery. Immediate postoperative enteral feeding should not be routine in well-nourished patients at low risk of nutrition-related complications.

Endogenous glucose production following injury increases with age.

To evaluate the influence of aging on the increase in endogenous glucose production that follows injury, we studied 22 fully resuscitated, clinically stable, previously healthy patients aged < or = 30 yr or > or = 60 yr admitted to hospital following injury, and 11 healthy volunteers in the same age groups. Endogenous glucose production was determined using a primed constant infusion of D-glucose-6,6-2d2. Urine cortisol and C-peptide were markedly higher in patients than volunteers (both P < 0.01), and urine C-peptide was lower in older than in younger patients (P < 0.05). Urine cortisol increased as a function of the interaction of age and Injury Severity Score (ISS) (r2 = 0.40, P < 0.001). Intracellular water was markedly lower and extracellular water greater in patients compared with volunteers (both P < 0.001), reflecting the loss of body cell mass and expansion of the extracellular space following injury. Endogenous glucose production (milligrams per minute per liter intracellular water) was best described as a function of ISS and age-ISS interaction (r2 = 0.35, all P < 0.05), and was increased 56% and 78% in younger and older patients, respectively, in comparison with the respective volunteer groups. Endogenous glucose production following injury increases in relation to the severity of injury and patient age. Greater cortisol elaboration and diminished insulin secretion in older patients may contribute to this age effect.

Aging exaggerates the blood glucose response to total parenteral nutrition.

OBJECTIVE: To determine the effect of age on the blood glucose and insulin responses to a clinical model of glucose loading (i.e., total parenteral nutrition [TPN] with hypertonic glucose), in patients with a variety of conditions. DESIGN: A prospective cohort study. SETTING: An adult university hospital. PATIENTS: Seventy-one consecutive, clinically stable patients receiving central TPN, excluding those with metabolic disease or receiving relevant medications. INTERVENTION: None. MAIN OUTCOME MEASURES: Serum levels of glucose, insulin, C-peptide and cortisol determined in peripheral venous blood obtained immediately before initiating TPN and again 48 to 96 hours later; acute physiology score (APS) and habitual level of physical activity (HAL). RESULTS: Serum levels of glucose, insulin and C-peptide increased following initiation of TPN (all p < 0.001). The serum glucose level during TPN administration increased as a function of both patient age and severity of illness (APS) (r2 = 0.37, all p < 0.01), whereas the serum insulin level was inversely related to age and increased as a function of serum glucose, glucose rate of infusion and HAL (r2 = 0.57, all p < 0.05). The serum C-peptide: insulin molar ratio did not vary with age. CONCLUSIONS: Aging and severity of illness interact to exaggerate the increases in blood glucose that accompany TPN with hypertonic glucose. Serum insulin responses to TPN decline with aging, likely reflecting reduced insulin secretion. Diminished insulin responses may contribute to hyperglycemia and represent a diminished anabolic signal in such patients. The acutely ill elderly patient is predisposed to hyperglycemia and should be monitored carefully even when pre-TPN blood glucose values are normal.

The effect of a rural preceptorship during residency on practice site selection and interest in rural practice.

Rural areas of the United States face serious shortages in health care personnel. This report evaluates the effect of a rural preceptorship during the second or third year of a family practice residency on interest in rural practice and on practice site selection. A majority of participants (n = 123) felt that this experience influenced their choice of a practice site. Furthermore, a large majority felt that it increased their interest in rural practice opportunities. Rural preceptorships during residency are a timely solution to increase the number of family physicians interested in rural practice.