Spinal or general anaesthesia for surgical repair of hip fracture and subsequent risk of mortality and morbidity: a database analysis using propensity score-matching

Around 76,000 people fracture their hip annually in the UK at a considerable personal, social and financial cost. Despite longstanding debate, the optimal mode of anaesthesia (general or spinal) remains unclear. Our aim was to assess whether there is a significant difference in mortality and morbidity between patients undergoing spinal anaesthesia compared with general anaesthesia during hip fracture surgery. A secondary analysis examined whether a difference exists in mortality for patients with pre-existing cardiovascular disease or chronic obstructive pulmonary disease. This was a clinical database analysis of patients treated for hip fracture in Nottingham, UK between 2004 and 2015. Propensity score-matching was used to generate matched pairs of patients, one of whom underwent each mode of anaesthesia. Data were analysed using conditional logistic regression, with 7164 patients successfully matched. There was no difference in 30- or 90-day mortality in patients who had spinal rather than general anaesthesia (OR 95%CI] 0.97 0.8–1.15]; p = 0.764 and 0.93 0.82–1.05]; p = 0.247 respectively). Patients who had a spinal anaesthetic had a lower-risk of blood transfusion (OR 95%CI] 0.84 0.75–0.94]; p = 0.003) and urinary tract infection (OR 95%CI] 0.72 0.61–0.84]; p < 0.001), but were more likely to develop a chest infection (OR 95%CI] 1.23 1.07–1.42]; p = 0.004), deep vein thrombosis (OR 95%CI] 2.18 1.07–4.45]; p = 0.032) or pulmonary embolism (OR 95%CI] 2.23 1.16–4.29]; p = 0.016). The mode of anaesthesia for hip fracture surgery resulted in no significant difference in mortality, but there was a significant difference in several measures of postoperative morbidity.