Malnutrition in elective surgery: How traditional markers might be failing surgeons and patients.

BACKGROUND: Serologic and anthropometric measures are commonly used as surrogate markers of nutritional status in clinical practice. In 2012, leading dietetic organizations published a standard definition of malnutrition based on clinical characteristics. We hypothesize that surrogate markers underrecognize clinical malnutrition and do not accurately identify patients at risk for adverse outcomes. METHODS: A single-institution cohort study of elective surgical inpatients from August 2015 to November 2017. Nutritional assessment was completed by trained registered dietitians using leading dietetic guidelines. Multivariable logistic regression was used to determine the association between malnutrition and perioperative outcomes. RESULTS: Among 953 elective surgical admissions, 456 underwent full clinical nutritional assessment. Of these, 202 (44.3%) met malnutrition criteria. In addition, 20.3% of patients with clinical malnutrition were underweight (<18.5 kg/m2) and 38.1% had a serum albumin <3.0 g/dL. Compared with nonmalnourished patients, those with clinical malnutrition had higher rates of any complication (46.5% vs 37.8%, P = .06), overall infectious complications (26.2% vs 14.6%, P = .002), surgical site infections (9.4% vs 3.9%, P = .02), and mortality (8.9% vs 1.9%, P = .001). Clinical malnutrition was associated with death (odds ratio 3.99; 95% confidence interval, 1.27-12.54), overall infectious complication (odds ratio 1.77; 95% confidence interval, 1.07-2.94), and surgical site infections (odds ratio 2.65; 95% confidence interval, 1.12-6.22). CONCLUSION: In this cohort of elective surgical patients, traditional markers failed to identify malnutrition in a substantial portion of patients who met clinical malnutrition criteria. Clinical malnutrition assessment is effective in identifying patients who may be at risk for suboptimal outcomes. Surgeons should implement clinical nutritional assessment and factor that information into their preoperative evaluation and management of elective surgical patients.

Hang Height of Enteral Nutrition Influences the Delivery of Enteral Nutrition.

PURPOSE: Adequate enteral nutrition (EN) delivery to critically ill patients is difficult to achieve. Given the large number of unpreventable influences affecting adequate caloric intake, further research on preventable influences of adequate EN administration is warranted. The purpose of this study was to evaluate whether hang height of EN formula, formula viscosity, or flow rate influences pump accuracy and formula delivery. METHODS: Formulas of varying viscosities (1.0, 1.5, and 2.0 kcal/mL) were infused at different hang heights (0, 6, 12, and 18 inches) and rates (20, 40, and 80 mL/h). The mean percent difference and the bias between the programmed volume, volume reported, and volume delivered were calculated for the different hang heights, formula compositions, and infusion rates studied. RESULTS: For all prespecified hang heights and infusion rates, the volume delivered was less than the programmed volume and volume reported; the mean percent difference increased as the hang height decreased. The volume was overestimated for both the programmed volume (14.4% ± 5.5%) and volume reported (12.9% ± 6.7%) compared with volume delivered. The overestimation bias was significantly influenced by differences in hang height as well as type of formula (P < .0001, each) but not by rate of delivery (P = .4633 for programmed volume and .8411 for volume reported). CONCLUSIONS: Measures should be taken in clinical practice to ensure adequate hang height of EN. Appropriate hang height of EN may result in more accurate delivery of nutrition provisions to the critically ill patient and subsequently reduce complications related to underfeeding.