Perioperative Hypothermia Is Associated With Increased 30-Day Mortality in Hip Fracture Patients in the United Kingdom: Α Systematic Review and Meta-analysis

Abstract

Objectives: To undertake a systematic review and meta-analysis to determine the relationship between perioperative hypothermia and mortality after surgery for hip fracture. Data Sources: A systematic literature search of Medline, EMBASE, CINAHL, and Cochrane CENTRAL databases was performed using the Cochrane methodology for systematic reviews with no publication year limit. Only studies available in the English language were included. Study selection: Predetermined inclusion criteria were patients of any age with a hip fracture, exposure was their body temperature and outcome was mortality rate. Any comparative study design was eligible. Data extraction: The quality of selected studies was assessed according to each study design with the Methodological Index for Non-Randomised Studies (MINORS) used for all the retrospective comparative studies. The GRADE approach was used to assess the quality of evidence. Data synthesis: A meta-analysis was conducted using a random-effects model. Results: The literature search identified 1016 records. After removing duplicates and those not meeting inclusion criteria, 3 studies measuring 30-day mortality were included. All included studies were carried out in the United Kingdom. The mortality rate was higher in the hypothermic groups as compared with the normothermic group in all the studies, with the difference being significant in 2 of the studies (P < 0.0001). The meta-analysis showed that low body temperature was associated with an increased mortality risk (estimated odds ratio: 2.660; 95% confidence interval: 1.948–3.632; P < 0.001) in patients undergoing surgery for hip fracture. Conclusions: This study shows that low body temperature in hip fracture patients is associated with an increased 30-day mortality risk in the United Kingdom. Randomized control trials are required to determine whether the association between perioperative hypothermia in hip fracture patients and mortality is causal. Nevertheless, based on this analysis, we urge the maintenance of normal body temperature in the perioperative period to be included in national hip fracture guidelines. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.