Jean C Burge

Changes in patients' taste acuity after Roux-en-Y gastric bypass for clinically severe obesity.

OBJECTIVE Patients who have undergone Roux-en-Y gastric bypass (RYGB) for clinically severe obesity often report an aversion to sweet foods and meat. This study was designed to determine whether changes in taste acuity occur after RYGB. DESIGN This prospective, repeated measures trial evaluated acuity for sweet (sucrose) and bitter (urea) tastes, zinc status, and reported changes in taste perceptions in patients undergoing RYGB for weight reduction. SUBJECTS Taste acuity and serum zinc level were measured in 14 subjects, 6 men and 8 women (mean preoperative body mass index [calculated as kg/m2] = 60.8 +/- 11.8 and mean age = 38.4 +/- 6 years), before surgery and 6 and 12 weeks after surgery. Inquiries regarding taste preferences were made at each postoperative visit with specific reference to sweets and meat. Serum zinc level was measured at the same visit. A noncontrolled comparison group of 4 subjects who were consuming a very-low-calorie diet also underwent taste acuity testing at similar intervals. MAIN OUTCOME MEASURES The main outcome measures were recognition taste thresholds, serum zinc levels, and taste preference changes. STATISTICAL ANALYSIS Analysis of variance with repeated measures over time, Pearson correlation coefficients, and post hoc analysis of variance were used to analyze data. RESULTS Mean recognition thresholds for sucrose were 0.047 +/- 0.03 mol/L preoperatively and fell significantly to 0.024 +/- 0.01 and 0.019 +/- 0.01 mol/L at 6 and 12 weeks postoperatively, respectively. Overall, there were no significant differences in taste thresholds for urea over time; a significant difference was noted, however, in the pattern of change for urea between patients who reported an aversion to meats and those who did not. Zinc concentrations did not change during the study. APPLICATION/CONCLUSIONS At 6 weeks postoperatively, all patients reported that foods tasted sweeter, and they modified food selection accordingly. Six patients reported an aversion to meats associated with increased nausea and vomiting. Acuity for sweet and bitter tastes may need to be considered when planning dietary modifications for patients undergoing RYGB.

Efficacy of Hypocaloric Total Parenteral Nutrition in Hospitalized Obese Patients: A Prospective, Double-Blind Randomized Trial

Obesity is a major health problem in the United States today. Traditionally, management of obese hospitalized patients has not differed from that of normal-weight patients, with calorie and protein needs based on current body weight and weight loss postponed until the acute illness has subsided. This study was undertaken to determine whether obese hospitalized patients (> 130% ideal body weight) requiring total parenteral nutrition and given hypocaloric (HC) feedings with adequate protein intake could achieve nitrogen balance comparable with that of controls (C) given isonitrogenous normocaloric formulas. Sixteen obese patients (HC = 9, C = 7) were randomized to either HC (50% resting metabolic energy expenditure, plus protein; calories:nitrogen = 75:1) or C (100% resting metabolic energy expenditure, plus protein; calories:nitrogen = 150:1) formulas. Resting metabolic energy expenditure was determined by indirect calorimetry on day 0 and weekly, and nitrogen balance was determined daily. The two groups were similar in Harris-Benedict predicted energy expenditure and metabolic energy expenditure, initial and final serum albumin, total iron-binding capacity, and weight loss. Total daily calorie and nonprotein calorie intake per kilogram body weight were 14 +/- 4.1 (HC) vs 25 +/- 4 (C) and 7 +/- 1.9 (HC) vs 20 +/- 3 (C), respectively. Protein intake was 1.23 +/- 0.4 (HC) vs 1.31 +/- 0.2 (C) g/kg per day. Initial respiratory quotients were similar and consistent with fasting (HC = 0.7 +/- 0.09 vs C = 0.66 +/- 0.09); final respiratory quotients in C patients reflected mixed fuel use (C = 0.82 +/- 0.11 vs HC = 0.7 +/- 0.12).(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in measured resting energy expenditure after Roux-en-Y gastric bypass for clinically severe obesity☆

BACKGROUND Roux-en-Y gastric bypass (RYGB) results in sustained weight loss and amelioration of comorbid conditions in patients with clinically severe obesity. The mechanism of weight loss after RYGB is not well defined. The objective of this study was to document the changes in measured resting energy expenditure (MREE) over time in patients with clinically severe obesity after RYGB. METHODS We prospectively studied MREE in 70 patients (11 male, 59 female; body mass index [BMI], 40 to 80 kg/m2) treated by RYGB. MREE was measured by indirect calorimetry before operation and at 6 weeks and 3, 6, 12, 18, and 24 months after operation. Patients were stratified to hypometabolic ([HM] MREE less than 85% of Harris-Benedict [HB] predicted; n = 22) or normal metabolic rate ([NM] MREE +/- 15% HB predicted; n = 48) before operation; mean BMIs were HM, 53.4 +/- 11.0 kg/m2; NM, 51.4 +/- 9.8 kg/m2; p = not significant. MREE, weight loss, percent excess body weight loss (EWL), and energy intake were determined at each time point. RESULTS Overall, MREE was significantly less than HB-predicted REE before operation (90 +/- 28%), but rose to become equal to the HB-predicted REE by 6 weeks (96 +/- 15%) and remained so. When stratified by initial metabolic rate, MREE increased significantly in the HM patients by 6 weeks, from 1329 +/- 604 kcal/day (55% of HB predicted) to 1882 +/- 398 kcal/day (88% of HB predicted) (p < 0.001), and MREE remained normal (2332 +/- 484 kcal/day to 2029 +/- 410 kcal/day) in the NM patients. Percent EWL was similar in both groups at each time. Energy intake was 2603 +/- 982 kcal/day before operation and fell to 815 +/- 196 kcal/day at 3 months, 969 +/- 241 kcal/day at 6 months, 1095 +/- 307 kcal/day at 12 months, 1259 +/- 466 kcal/day at 18 months, and 1373 +/- 620 kcal/day at 24 months, and was similar between the groups at each time point. Percent HB-predicted REE increased significantly after operation despite a significant decrease in energy intake. CONCLUSIONS RYGB is associated with significant changes in MREE over time. In NM patients MREE fell over time consistent with weight loss but remained normal, whereas patients who were hypometabolic exhibited increases in MREE toward normal. These changes in MREE occurred despite reduced energy intake comparable to a very low calorie diet. This paradoxical effect on MREE may contribute to the enhanced weight loss associated with RYGB.

The Effect of Catheter Type and Site on Infection Rates in Total Parenteral Nutrition Patients

Infections pose a major problem in patients receiving total parenteral nutrition. Controversy continues concerning the effect of catheter type (triple-, double-, single-lumen, or pulmonary artery), insertion site (subclavian, internal jugular, or femoral vein), and the incidence of catheter-related infections. We retrospectively studied multi-lumen catheter use for total parenteral nutrition over a 6-month period in 192 patients, a total of 3334 catheter days. Nonintensive care unit catheters were inserted by the Nutrition Support Service, and intensive care unit catheters were inserted by the intensive care unit staff. All catheters were cared for using Nutrition Support Service protocols, with multi-lumen catheters changed every 7 to 10 days and pulmonary artery catheters changed every 4 days. Infections were determined by semiquantitative cultures (> 15 colonies/plate). The incidence of infections for triple-lumen catheters was 5 (subclavian), 17 (internal jugular), and 36% (femoral) respectively; total infection rate for triple-lumen catheters was 10%. Infection rates for pulmonary artery catheters were 4 (subclavian), and 6% internal (jugular site), respectively, the overall infection rate was 5%. There were no differences in infection rates at any site based on catheter type; however, when triple-lumen catheter sites were compared, the differences were significant (p < .001 vs subclavian, chi 2). Catheter duration was 7.8 days (subclavian),, 7.3 days (internal jugular), and 4.6 (femoral) days. These data suggest that the use of multi-lumen catheters for total parenteral nutrition is safe, that there is a benefit associated with the subclavian route, and that the femoral site should be avoided.

Urinary Ammonia Plus Urinary Urea Nitrogen as an Estimate of Total Urinary Nitrogen in Patients Receiving Parenteral Nutrition Support

Nitrogen balance has historically been estimated by using urinary urea nitrogen (UUN) multiplied by a factor of 1.25 to account for nonurea nitrogen present in the urine. Recently, the reliability of UUN as an estimate of nitrogen losses has been questioned and the use of total urinary nitrogen (TUN) has been proposed as a more accurate measure of urinary nitrogen losses. However, analysis of TUN losses is not readily available in many hospital laboratories. Because ammonia is the major fluctuating component of urinary nonurea nitrogen and equipment to measure urinary ammonia is available in most hospitals, this study was undertaken to determine whether urinary ammonia plus UUN provides a clinically useful approximation of TUN. Twenty-four-hour urine samples acidified with boric acid during collection from 20 patients (a total of 42 samples) receiving total parenteral nutrition were analyzed for UUN, ammonia, and TUN. The UUN values ranged from 4.9 to 42.4 g/24 h. The mean difference between TUN and UUN was 1.99 +/- 0.27 g/24 h. The mean difference between TUN and UUN plus ammonia was 0.78 +/- 0.27 g/24 h. Thus, UUN alone accounted for 90% and the combination of UUN plus urinary ammonia accounted for 96% of TUN. These data suggest that UUN plus ammonia does provide a greater level of reliability as an estimate of TUN than UUN alone.

Nutrition Support of Obese Hospitalized Patients

Obesity is a chronic disease that affects 33% of the adult population and 30% to 40% of the hospitalized adult population. Obesity can be defined with the use of percent of ideal body weight, but because of a number of problems associated with this method, body mass index has become the accepted measure. Nutrition assessment and selection of route of nutrition support are similar in the obese and normal weight patient. A variety of methods for estimating energy and protein needs in the obese patient are available but become increasingly unreliable as the degree of obesity increases. Measuring energy needs becomes appropriate as obesity becomes more severe. A strategy that uses hypocaloric nutrition support in the obese hospitalized patient is reviewed.

Obesity treatment: The role of surgery

Abstract Obesity, defined as an excess in body fat, constitutes one of the most common and significant health problems in the United States today. The current prevalence of overweight is 33.4% of US adults. Obesity has been shown to be an independent risk factor for the development of cardiovascular diseases such as hypertension, dyslipidemia, myocardial infarction and stroke. Death from cardiovascular causes increases significantly with body weight. This article will review the modalities of treatment available with particular attention to surgical treatment of obesity. The indications, associated risks, current procedures, and expected results of surgical treatment of obesity will be discussed.

Characterization of a murine model of acute lung injury (ALI): a prominent role for interleukin-1.

This report describes a model developed to study local and systemic events that occur as a result of acute lung injury (ALI). C57BL/6J mice were injected with a single intravenous dose (2, 4, and 6 micrograms) of 12-O-tetradecanoylphorbol-13-acetate (TPA). At 1, 2, 4, 12, 24, and 48 h, after injection, plasma was collected by sinus orbital puncture, bronchoalveolar lavage (BAL) was performed and cells and fluid were collected, lungs were perfused, and pulmonary tissue was isolated and processed for histological, immunochemical, and gene expression studies. The results indicate a dose-dependent increase in animal distress and a decrease in survival. TPA induced an early systemic response, reflected as an initial decrease in numbers of peripheral blood neutrophils at 1 h, followed at 2 h by a sustained increase. There was dose- and time-dependent increase in IL-1 beta mRNA synthesis, detected using RT-PCR, and in immunoreactive IL-1 alpha produced by both tissue-fixed pulmonary cells and cells within alveolar spaces. Infiltration of neutrophils into pulmonary tissue and increased protein content in BAL fluid was detected 2 h after injection of TPA. Disruptions in pulmonary architecture accompanied by the presence of highly vacuolated macrophages within the alveolar spaces and interstitial tissue were evident after IV injection of TPA. The study shows that injection of TPA induces reproducible dose- and time-dependent alterations in cell types, numbers, state of activation, and production of soluble mediators in the peripheral circulation within BAL and pulmonary tissue. Thus, this model offers a means to examine the cellular basis for the local and systemic alterations observed during ALI.

Nutrition support billing practices: results of a nationwide survey and responses from the Health Care Financing Administration.

In response to numerous changes in reimbursement for physician services, a survey was conducted of physician directors of nutrition support services to obtain information about current physician billing practices and reimbursement for nutrition support. Demographic data were obtained concerning the type of practice and institution, percent of time and income derived from nutrition support, and the source of individual billing practices. Responses to six clinical scenarios provided information about billing practices. The responses were collated, analyzed, and then compared with those of a senior official at the Health Care Financing Administration (HCFA). This report summarizes the results of the survey and the responses from HCFA. It is hoped that this information will be useful to nutrition support practitioners and administrators in understanding various aspects of billing for physician services for nutrition support.