Variation in the application of methods used for predicting energy requirements in acutely ill adult patients: a survey of practice

Energy Expenditure in Upper Gastrointestinal Cancers: a Scoping Review

Malnutrition is prevalent in people with upper gastrointestinal (GI) cancers and is associated with shorter survival and poor quality of life. In order to effectively prevent or treat malnutrition, nutrition interventions must ensure appropriate energy provision to meet daily metabolic demands. In practice, the energy needs of people with cancer are frequently estimated from predictive equations which are not cancer-specific and are demonstrated to be inaccurate in this population. The purpose of this scoping review was to synthesize the existing evidence regarding energy expenditure in people with upper GI cancer. Three databases (Ovid MEDLINE, Embase via Ovid, CINAHL plus) were systematically searched to identify studies reporting on resting energy expenditure using indirect calorimetry and total energy expenditure using doubly labeled water (DLW) in adults with any stage of upper GI cancer at any point from diagnosis. A total of 57 original research studies involving 2,125 individuals with cancer of the esophagus, stomach, pancreas, biliary tract, or liver were eligible for inclusion. All studies used indirect calorimetry, and one study used DLW to measure energy expenditure, which was reported unadjusted in 42 studies, adjusted for body weight in 32 studies, and adjusted for fat-free mass in 13 studies. Energy expenditure in upper GI cancer was compared with noncancer controls in 19 studies and measured compared with predicted energy expenditure reported in 31 studies. There was heterogeneity in study design and in reporting of important clinical characteristics between studies. There was also substantial variation in energy expenditure between studies and within and between cancer types. Given this heterogeneity and known inaccuracies of predictive equations in patients with cancer, energy expenditure should be measured in practice wherever feasible. Additional research in cohorts defined by cancer type, stage, and treatment is needed to further characterize energy expenditure in upper GI cancer.

Perspectives of Nursing Homes Staff on the Nature of Residents-Initiated Call Lights

Little research has been conducted to capture the perceptions of nursing home staff when using the call light system. There is also a lack of information regarding the effects that these perceptions of the call light system have on their workload, safety, quality of care, or overall satisfaction. In response to the high volume of complaints from residents and their families regarding long response times to call light alarms, we developed this exploratory cross-sectional survey study. This study aims to capture nursing home staff experiences while using a call light system; to investigate the challenges the staff face when using the system; and to determine how these challenges contribute to their workload, performance, and satisfaction. A survey instrument was developed and distributed to all 153 of the nursing staff, certified nursing assistants, and licensed practical nurses in a nursing home in upstate New York. A total of 105 completed surveys were retrieved for an overall response rate of 68.63%. Descriptive analysis, Pearson correlation, and the Kruskal-Wallis test were used to analyze the collected data. The results showed a significant correlation between the processes of being notified and locating call light alarms and workload. The staff reported many usability challenges that may contribute to longer response time such as lack of prioritization, low/no discriminability, noise, and overwrite previous alarm. In addition, 78% of the staff agreed that responding to a call light can prevent serious harm; however, 56% of the staff agreed that call light system is not meaningful; and around 78% think that call light system is disruptive in the environment and source for constant noise. The study finds that incorporating the insights provided by nursing home staff may improve the acceptance of new and existing technology, which ultimately improves the delivery of care through greater usability.

Does Propofol Sedation Contribute to Overall Energy Provision in Mechanically Ventilated Critically Ill Adults? A Retrospective Observational Study

BACKGROUND

Propofol sedation is common in critically ill patients, providing energy of 1.1 kcal/mL when administered as a 1% solution. We aimed to determine the proportion of energy administered as propofol on days 1-5 in the intensive care unit (ICU) and any association with outcomes.

METHODS

Retrospective observational study in a quaternary ICU from January-December 2012. Inclusion criteria were length of stay (LOS) ≥5 days, age ≥18 years, and provision of mechanical ventilation (MV) for ≥5 days. Outcome measures included proportion of total daily energy provided as propofol, overall energy balance, hospital mortality, duration of MV, and ICU LOS.

RESULTS

Data from 370 patients were analyzed, 87.8% (n = 325) of whom received propofol during days 1-5 in ICU. A median [interquartile range (IQR)] of 119 [50-730] kcal was provided as propofol per patient-day. Proportion of energy provided by propofol as a percentage of total energy delivered was 55.4%, 15.4%, 9.3%, 7.9%, and 9.9% days 1-5, respectively. Patients administered propofol received a greater proportion of their total daily energy prescription compared with those who were not (P < .01). Proportion of energy provided as propofol was not significantly different based on hospital mortality (P = .62), duration of MV (P = .50), or ICU LOS (P = .15).

CONCLUSION

Propofol contributes to overall energy intake on days 1-5 of ICU admission. Energy balance was higher in those receiving propofol. No association was found between the proportion of energy delivered as propofol and outcomes.

Comparison between resting metabolic rate and indirect calorimetry in postmenopausal women

ABSTRACT Objective To compare resting metabolic rate values determined by indirect calorimetry with values estimated using different predictive equations in lean and overweight postmenopausal women. Methods Twenty-four women, who had stopped menstruating for at least two years, were subjected to anthropometric measurements and indirect calorimetry after 12-hour overnight fasting to determine, mathematically and experimentally, resting metabolic rate values. Results There was no difference in the indirect calorimetry values between the groups evaluated. Difference values of resting metabolic rate were obtained with all equations used. For the lean women, there was no difference between the values obtained by indirect calorimetry and those estimated using the equations proposed by Food and Agricultural Organization, Fredix, Lazzer, and Schofield. However, in the overweight group, the resting metabolic rate values estimated using the Institute of Medicine, Berstein and Owen equations were different from those obtained by indirect calorimetry. Conclusion This study suggests that differences in body composition in postmenopausal women influence the accuracy of predictive equations, demonstrating the need for more accurate estimation methods for resting metabolic rate in postmenopausal women with different body compositions.

Resting energy expenditure in critically ill patients: Evaluation methods and clinical applications

Patients on intensive care present systemic, metabolic, and hormonal alterations that may adversely affect their nutritional condition and lead to fast and important depletion of lean mass and malnutrition. Several factors and medical conditions can influence the energy expenditure (EE) of critically ill patients, such as age, gender, surgery, serious infections, medications, ventilation modality, and organ dysfunction. Clinical conditions that can present with EE change include acute kidney injury, a complex disorder commonly seen in critically ill patients with manifestations that can range from minimum elevations in serum creatinine to renal failure requiring dialysis. The nutritional needs of this population are therefore complex, and determining the resting energy expenditure is essential to adjust the nutritional supply and to plan a proper diet, ensuring that energy requirements are met and avoiding complications associated with overfeeding and underfeeding. Several evaluation methods of EE in this population have been described, but all of them have limitations. Such methods include direct calorimetry, doubly labeled water, indirect calorimetry (IC), various predictive equations, and, more recently, the rule of thumb (kcal/kg of body weight). Currently, IC is considered the gold standard.

Resting energy expenditure of morbidly obese patients using indirect calorimetry: a systematic review

The increasing proportion of acutely ill hospital patient admissions presenting with a morbidly obese body mass index (BMI ≥ 40 kg m(-2) ) as a comorbidity is an emerging clinical concern. Suboptimal food intake and malnutrition is prevalent in the acute care hospital setting. The energy requirements necessary to prevent malnutrition in acutely ill patients with morbid obesity remains unclear. The aim of this systematic review was to identify studies in the literature that have used indirect calorimetry to measure the resting energy expenditure of patients with morbid obesity to establish their minimum energy requirements and the implications for optimal feeding practices in acutely ill hospitalized patients. A total of 20 studies from PubMed, Cochrane Library and Embase met the inclusion criteria and were reviewed. All articles were graded using the Australian National Health and Medical Research Council levels of evidence and given a quality rating using the American Dietetic Association recommendations. Studies were categorized according to the mean BMI of its subjects. The most commonly measured resting energy expenditures for morbidly obese patients are between 2,000 and 3,000 kcal d(-1) (8,400-12,600 kJ d(-1) ). Activity and injury factors of acutely ill morbidly obese patients could result in significantly greater energy requirements for this patient group and are unlikely to be met by standard hospital menus. Establishing the minimum energy requirements for this population group will help inform adequate and accurate energy provision in the acute setting. Outcomes of underfeeding and overfeeding in morbidly obese patients warrant further research.

Resting energy expenditure measured longitudinally following hip fracture compared to predictive equations: is an injury adjustment required?

The present study measuring resting energy expenditure (REE; kJ/d) longitudinally using indirect calorimetry in six elderly women aged ≥70 years following surgery for hip fracture, describes changes over time (days 10, 42 and 84 post-injury) and compares measured values to those calculated from routinely applied predictive equations. REE was compared to REE predicted using the Harris Benedict and Schofield equations, with and without accounting for the theoretical increase in energy expenditure of 35 % secondary to physiological stress of injury and surgery. Mean (95 % CI) measured REE (kJ/d) was 4704 (4354, 5054), 4090 (3719, 4461) and 4145 (3908, 4382) for days 10, 42 and 84, respectively. A time effect was observed for measured REE,P=0·003. Without adjusting for stress the mean difference and 95 % limits of agreement for measured and predicted REE (kJ/kg per d) for the Harris Benedict equation were 1 (−9, 12), 10 (2, 18) and 9 (1, 17) for days 10, 42 and 84, respectively. The mean difference and 95 % limits of agreement for measured and predicted REE (kJ/kg per d) for the Schofield equation without adjusting for stress were 8 (−3, 19), 16 (6, 26) and 16 (10, 22) for days 10, 42 and 84, respectively. After adjusting for stress, REE predicted from the Harris Benedict or Schofield equations overestimated measured REE by between 38 and 69 %. Energy expenditure following fracture is poorly understood. Our data suggest REE was relatively elevated early in recovery but declined during the first 6 weeks. Using the Harris Benedict or Schofield equations adjusted for stress may lead to overestimation of REE in the clinical setting. Further work is required to evaluate total energy expenditure before recommendations can be made to alter current practice for calculating theoretical total energy requirements of hip fracture patients.

Accurate Determination of Energy Needs in Hospitalized Patients

OBJECTIVE

To evaluate the accuracy of seven predictive equations, including the Harris-Benedict and the Mifflin equations, against measured resting energy expenditure (REE) in hospitalized patients, including patients with obesity and critical illness.

DESIGN

A retrospective evaluation using the nutrition support service database of a patient cohort from a similar timeframe as those used to develop the Mifflin equations.

SUBJECTS/SETTING

All patients with an ordered nutrition assessment who underwent indirect calorimetry at our institution over a 1-year period were included.

INTERVENTION

Available data was applied to REE predictive equations, and results were compared to REE measurements.

MAIN OUTCOME MEASURES

Accuracy was defined as predictions within 90% to 110% of the measured REE. Differences >10% or 250 kcal from REE were considered clinically unacceptable.

STATISTICAL ANALYSES PERFORMED

Regression analysis was performed to identify variables that may predict accuracy. Limits-of-agreement analysis was carried out to describe the level of bias for each equation.

RESULTS

A total of 395 patients, mostly white (61%) and African American (36%), were included in this analysis. Mean age+/-standard deviation was 56+/-18 years (range 16 to 92 years) in this group, and mean body mass index was 24+/-5.6 (range 13 to 53). Measured REE was 1,617+/-355 kcal/day for the entire group, 1,790+/-397 kcal/day in the obese group (n=51), and 1,730+/-402 kcal/day in the critically ill group (n=141). The most accurate prediction was the Harris-Benedict equation when a factor of 1.1 was multiplied to the equation (Harris-Benedict 1.1), but only in 61% of all the patients, with significant under- and over-predictions. In the patients with obesity, the Harris-Benedict equation using actual weight was most accurate, but only in 62% of patients; and in the critically ill patients the Harris-Benedict 1.1 was most accurate, but only in 55% of patients. The bias was also lowest with Harris-Benedict 1.1 (mean error -9 kcal/day, range +403 to -421 kcal/day); but errors across all equations were clinically unacceptable.

CONCLUSIONS

No equation accurately predicted REE in most hospitalized patients. Without a reliable predictive equation, only indirect calorimetry will provide accurate assessment of energy needs. Although indirect calorimetry is considered the standard for assessing REE in hospitalized patients, several predictive equations are commonly used in practice. Their accuracy in hospitalized patients has been questioned. This study evaluated several of these equations, and found that even the most accurate equation (the Harris-Benedict 1.1) was inaccurate in 39% of patients and had an unacceptably high error. Without knowing which patient's REE is being accurately predicted, indirect calorimetry may still be necessary in difficult to manage hospitalized patients.

Estimating resting energy expenditure in patients requiring nutritional support: a survey of dietetic practice

Estimation of resting energy expenditure (REE) involves predicting basal metabolic rate (BMR) plus adjustment for metabolic stress. The aim of this study was to investigate the methods used to estimate REE and to identify the impact of the patient's clinical condition and the dietitians' work profile on the stress factor assigned. A random sample of 115 dietitians from the United Kingdom with an interest in nutritional support completed a postal questionnaire regarding the estimation of REE for 37 clinical conditions. The Schofield equation was used by the majority (99%) of dietitians to calculate BMR; however, the stress factors assigned varied considerably with coefficients of variation ranging from 18.5 (cancer with cachexia) to 133.9 (HIV). Dietitians specializing in gastroenterology assigned a higher stress factor to decompensated liver disease than those not specializing in gastroenterology (19.3 vs 10.7, P=0.004). The results of this investigation strongly suggest that there is wide inconsistency in the assignment of stress factors within specific conditions and gives rise to concern over the potential consequences in terms of under- or overfeeding that may ensue.

Current practices in the delivery of parenteral nutrition in Australia

OBJECTIVE

To determine current practice in the delivery of parenteral nutrition (PN) in Australian hospitals.

DESIGN

A cross-sectional mail survey.

SETTING

Acute-care adult hospitals with greater than 200 beds in Australia.

SUBJECTS

A total of 67 hospitals (65.7% response rate).

INTERVENTION

Surveys were posted to hospitals. A reminder letter with a second copy of the survey was posted 3 weeks later to non-respondents.

RESULTS

Twenty-seven (40.3%) of the hospitals have a PN team and 50 (74.6%) have a hospital protocol for PN delivery. An inaccessible or non-functional gastrointestinal tract is the most common indicator for commencing PN. Fat infusion is calculated by 24 (38.7%) respondents with a mean (s.d.) maximum amount of fat provided of 2.0 (0.7) g/kg/day. Over half (n=35) reported calculating carbohydrate infusion at a maximum amount of 5.4 (1.0) mg/kg/min. Two-thirds (n=41) reported commencing PN at a rate of 50% or less of goal rate. Blood glucose levels (BGL) were monitored at least once per day by the majority of respondents (n=56, 83.6%). Insulin infusion was commenced at varying BGL. Most respondents (n=40, 59.7%) reported ceasing PN when at least half of the patient's requirements are being met either orally or enterally. A number of practice guidelines were identified and the results of the survey were compared with these guidelines.

CONCLUSIONS

Where there are clear practice guidelines, current practice appears to be in line with these recommendations, however, where evidence is lacking, practice is varied.

Formula delivery in patients receiving enteral tube feeding on general hospital wards: the impact of nasogastric extubation and diarrhea

OBJECTIVE

In contrast to the intensive care unit, little is known of the percentage of formula delivered to patients receiving enteral tube feeding (ETF) on general wards or of the complications that affect its delivery. This study prospectively investigated the incidence of nasogastric extubation and diarrhea in patients starting ETF on general wards and examined their effect on formula delivery.

METHODS

In a prospective observational study, the volume of formula delivered to patients receiving ETF on general wards was compared with the volume prescribed. The incidence of nasogastric extubation and diarrhea was measured and its effect on formula delivery calculated.

RESULTS

Twenty-eight patients were monitored for a total of 319 patient days. The mean +/- SD volume of formula prescribed was 1460 +/- 213 mL/d, whereas the mean volume delivered was only 1280 +/- 418 mL/d (P < 0.001), representing a mean percentage delivery of 88 +/- 25% of prescribed formula. Nasogastric extubation occurred in 17 of 28 patients (60%), affecting 53 of the 319 patient days (17%). The percentage of formula delivered on days when the nasogastric tube remained in situ was 96 +/- 12% and on days when nasogastric extubation occurred it was only 45 +/- 31% (P < 0.001). Diarrhea affected 39 of 319 patient days (12%) but there was no difference in formula delivery on days when diarrhea did or did not occur (78% versus 89%, P = 0.295). There was a significant, albeit small, negative correlation between the daily stool score and formula delivery (correlation coefficient -0.216, P < 0.001).

CONCLUSIONS

Formula delivery is marginally suboptimal in patients receiving ETF on general wards. Nasogastric extubation is common and results in an inherent cessation of ETF until the nasogastric tube is replaced and is therefore a major factor impeding formula delivery. Diarrhea is also common but does not result in significant reductions in formula delivery.