A health status assessment of the impact of weight loss following Roux-en-Y gastric bypass for clinically severe obesity.

BACKGROUND: The field of "medical outcomes" emphasizes effects of medical treatments on quality of life as seen from the patient's perspective. The increasing incidence of obesity has had tremendous impact on the physical, psychological, social, and economic health of our nation with important longterm implications for the development of future social and health care policies. This study evaluated the effects of clinically severe obesity on overall health status measured in a standardized fashion and the impact of durable weight loss achieved through surgical intervention. STUDY DESIGN: Patients scheduled for Roux-en-Y gastric bypass for treatment of obesity were prospectively evaluated. At the preoperative visit, each patient completed Short Form 36 (SF-36). Postoperatively, patients were again asked to complete SF-36, in person or through a telephone interview at an interim point (3 to 12 months) and after their weight had reached a plateau (>18 months). RESULTS: The mean body mass index (BMI) was 51+/-10 kg/m2 preoperatively (range 38 to 85 kg/m2). Mean BMI was 45+/-10 kg/m2 (range 33 to 78 kg/m2) at the interim point and 35+/-8 kg/m2 (range 28 to 55 kg/m2) at plateau. The weight change for the group was from 306+/-8 lb (138+/-4 kg) preoperatively to 211+/-55 lb (96+/-25 kg) at the plateau, with the average percent of excess body weight lost being 63+/-23% at the plateau. Preoperatively, patients with clinically severe obesity scored significantly lower than the normal population in all areas except Role Activities (Emotional Factors). At the plateau period, patients demonstrated significant improvement in limitations in all areas compared with preoperative values and scores were the same as (Physical Activities, Role Activities [Physical Factors], General Mental Health, General Health Perceptions), or significantly better than (Social Functioning, Role Activities [Emotional Factors], Bodily Pain, Vitality), the national "normal" population. CONCLUSION: Clinically severe obesity is a chronic disabling disease that results in significantly decreased health status in seven of the eight areas measured by SF-36. This disability resolves with successful weight reduction. In some areas, function even surpasses the national "normal" population. Surgical treatment of clinically severe obesity has a profoundly positive impact on patients' perception of their health status.

Comparison of indirect calorimetry, the Fick method, and prediction equations in estimating the energy requirements of critically ill patients.

BACKGROUND: Accurate measurement of resting energy expenditure (REE) is helpful in determining the energy needs of critically ill patients requiring nutritional support. Currently, the most accurate clinical tool used to measure REE is indirect calorimetry, which is expensive, requires trained personnel, and has significant error at higher inspired oxygen concentrations. OBJECTIVE: The purpose of this study was to compare REE measured by indirect calorimetry with REE calculated by using the Fick method and prediction equations by Harris-Benedict, Ireton-Jones, Fusco, and Frankenfield. DESIGN: REEs of 36 patients [12 men and 24 women, mean age 58+/-22 y and mean Acute Physiology and Chronic Health Evaluation II score 22+/-8] in a hospital intensive care unit and receiving mechanical ventilation and total parenteral nutrition (TPN) were measured for > or = 15 min by using indirect calorimetry and compared with REEs calculated from a mean of 2 sets of hemodynamic measurements taken during the metabolic testing period with an oximetric pulmonary artery catheter. RESULTS: Mean REE by indirect calorimetry was 8381+/-1940 kJ/d and correlated poorly with the other methods tested (r = 0.057-0.154). This correlation did not improve after adjusting for changes in respiratory quotient (r2 = 0.28). CONCLUSIONS: These data do not support previous findings showing a strong correlation between REE determined by the Fick method and other prediction equations and indirect calorimetry. In critically ill patients receiving TPN, indirect calorimetry, if available, remains the most appropriate clinical tool for accurate measurement of REE.

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.

Hypoenergetic nutrition support in hospitalized obese patients: a simplified method for clinical application.

Nutrition support in obese hospitalized patients is controversial, with some practitioners advocating restricted energy or hypoenergetic feedings when patients are being actively treated for another disease. To eliminate the need for indirect calorimetry, this randomized, double-blind, prospective study was undertaken to determine whether obese hospitalized patients given a hypoenergetic parenteral regimen administered to provide 2 g protein x kg ideal body wt (IBW)(-1) x d(-1), could achieve nitrogen balance comparable with that of control subjects given isonitrogenous normoenergetic formula. Thirty obese hospitalized patients with an average body mass index (BMI; in kg/m2) of 35 were randomly assigned to the hypoenergetic [energy (kJ):nitrogen (g) = 314:1; energy (kcal):nitrogen (g) = 75:1; n = 16] or control [energy (kJ):nitrogen (g) = 628:1; energy (kcal):nitrogen (g) = 150:1; n = 14] formulas. The initial formula volume administered provided 2 g protein x kg IBW(-1) x d(-1). Nitrogen balance was determined on day 0 and weekly. The total daily energy intake [per kg actual body weight (ABW)] was 57 +/- 12 kJ (hypoenergetic) compared with 94 +/- 21 kJ (control), P < 0.001, and the nonprotein energy intake was 36 +/- 10 kJ (hypoenergetic) compared with 73 +/- 17 kJ (control), P < 0.001. Protein intake was the same per ABW, 2.0 +/- 0.2 and 2.0 +/- 0.1 g kg IBW(-1) x d(-1), NS, for the hypoenergetic and control formulas, respectively. Mean net nitrogen balance was not significantly different between the groups, even after patients were subgrouped by illness, nor was the percentage of patients achieving positive nitrogen balance. Duration of treatment averaged 10.5 +/- 2.6 d. Weight change did not differ significantly between groups. These data indicate that patients receiving hypoenergetic feedings providing 2 g protein x kg IBW(-1) x d(-1) achieved nitrogen balance comparable with patients given conventional total parenteral nutrition regimens, even when critically ill.

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.

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.

Increased incidence of nosocomial infections in obese surgical patients.

Obesity has long been considered a potential risk factor for poor outcome following surgical procedures. However, controversy exists regarding the clinical impact of this problem because of a paucity of data regarding the incidence and risk of nosocomial infections in obese surgical patients. This retrospective study was undertaken to compare the nosocomial infection rate in obese and normal weight surgical patients. All patients undergoing general, urologic, vascular, thoracic, or gynecologic surgical procedures between October 1 and December 31, 1991, were reviewed. Nosocomial infection data were obtained from the Department of Hospital Epidemiology. A total of 849 patients were evaluated, of which 536 (63%) were normal weight (BMI < 27 kg/m2), 175 (21%) were obese (BMI 27-31 kg/m2), and 138 (16%) were severely obese (BMI > 31 kg/m2). Age, mortality, and American Society of Anesthesia (ASA) risk scores did not differ among the three groups. There were significant increases in the number and percent of nosocomial infections in the obese populations, with rates of 0.05 per cent in normal weight, compared to 2.8 per cent and 4.0 per cent in obese and severely obese groups (P < 0.01). Infections consisted of seven wound infections, five C. difficile infections, one pneumonia, and three bacteremias. No differences in distribution between groups were evident. Mortality was similar among the groups. These data support the hypothesis that obesity is a significant risk factor for clinically relevant nosocomial infections in surgical patients.

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.

Satisfaction with medical care. It's easier to please patients than their family members and friends.

The authors conducted a multi-site study to compare the level of satisfaction with medical care and services between patients and their family/friends. Hierarchical regression results controlling for patient age, gender, medical service performed, and other factors suggest that inpatients are more satisfied with the care rendered by physicians and nurses, as well as with their overall hospital stay, than are their family members and friends. The authors speculate about why this is so and what health care providers can do about it.

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)

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.

Taste acuity and zinc status in chronic renal disease.

The malnutrition often associated with progressive renal failure may be related to a progressive deterioration of taste acuity. To determine the relationships between taste acuity, zinc status, and progressive renal failure, 27 subjects were divided into three groups and classified as having mild, moderate, or severe renal failure, with creatinine clearance of 41 to 75, 15 to 40, and 5 to 14 ml/minute, respectively. The subjects were evaluated for recognition taste thresholds for sour and sweet by the Cornsweet method. Serum, urinary, and salivary levels for zinc were determined by atomic absorption techniques. Food diaries were kept for two days; intakes of protein and zinc were calculated from the diaries. There was a significant (p less than .01) inverse relationship between creatinine clearance and recognition taste thresholds for sour and sweet. Serum zinc levels were significantly lower (p less than .01) for subjects with severe renal failure than for subjects with mild renal failure. The subjects who ingested more protein also ingested more zinc.