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

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.

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.

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).

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.