P16. Impact of preoperative malnutrition on drain output and postoperative complications in elderly patients undergoing open lumbar spine surgery

Abstract

Background Context

Despite ongoing controversy regarding routine drain use in open lumbar spine surgery, postoperative drainage remains commonly utilized worldwide. With an increase in spine surgery among the elderly population, optimization of perioperative management including nutrition has become an important focus. However, the impact of preoperative nutritional status on drain output and postoperative complications remains unclear.

Purpose

To examine the relationships between preoperative malnutrition, subfascial drain output, and in-hospital postoperative complications in elderly patients undergoing open lumbar spine surgery.

Study Design/Setting

Retrospective single-center cohort study.

Patient Sample

Ninety-seven patients aged ≥65 years undergoing open lumbar decompression and/or fusion at a tertiary spine center from 2021 to 2022.

Outcome Measures

Occurrence of all-cause postoperative complication during initial hospitalization.

Methods

Patients were divided into malnutrition and normal nutrition groups based on the Geriatric Nutritional Risk Index (GNRI<98); %drain output was defined as drain output volume divided by total perioperative blood loss. Patient demographics, surgical details including drain output, and postoperative complications were collected and compared between groups. Multivariable logistic regression analysis was performed to identify predictors of in-hospital postoperative complications.

Results

Of 97 patients, 17 cases (18%) had malnutrition before surgery. Patients with malnutrition were older (78 years vs 75 years) with lower BMI (21 vs 25) but no significant difference in sex, diabetes prevalence, or anticoagulant/antiplatelet medication. Drains were removed based on duration and output on postoperative days 2-3 in this cohort. There was no difference in surgical procedure (decompression, 59% vs 44%), fused segments (2.1 vs 2.3), operating time (2.6 hours vs 3.1 hours), intraoperative blood loss (174 mL vs 267 mL), drain output (327 mL vs 276 mL), and total perioperative blood loss (501 mL vs 544 mL) between groups. However, the malnutrition group had a higher %drain output (68% vs 57%) and increased in-hospital postoperative complications (59% vs. 13%), including surgical site infection, urinary tract infection, and delirium (p<.05). After adjusting for confounding factors, preoperative malnutrition (OR 23.6) and %drain output (OR 0.95) were independent predictors of in-hospital postoperative complications.

Conclusions

Preoperative malnutrition increased the risk of in-hospital postoperative complications directly as well as indirectly via increasing %drain output. Our findings highlight the need to optimize nutritional status before lumbar spine surgery in the elderly population.

FDA Device/Drug Status

This abstract does not discuss or include any applicable devices or drugs.