Would You Have a General Anaesthetic for Hip Fracture Surgery?

Michael McEvoy is an ST6 in Intensive Care Medicine and Anaesthesia in the North West Deanery. He is also a Cochrane Anaesthesia Research Group Dissemination Fellow.

All members of the multi-disciplinary team involved in the management of patients with hip fractures are well aware of the significant mortality and morbidity generated by the condition.  This MDT must be congratulated as the previously stubborn 30-day mortality rate of 10.9% in 2007 has now dropped to 6.9% in the last National Hip Fracture Database Report and 67.5% of patients return to their original residence at 120 days.  There is still, understandably, much desire to improve outcomes further, however, as many patients will suffer significant morbidity such as pneumonia, delirium and myocardial infarction, and the average in-hospital stay is not significantly falling, leading to a total annual national requirement of 1.5 million bed days.

Hip fracture is the most common reason for older people to have emergency anaesthesia and as every anaesthetic has the potential to cause significant harm it is unsurprising that the type of anaesthesia has been long debated as an area which may contribute to morbidity and mortality.  I have often overheard on the wards that the trauma patient who had a general anaesthetic was much more confused postoperatively and “you can always tell which patients have had a GA”.  Anecdotally, even at a recent anaesthesia conference, the audience largely opted for spinal anaesthesia when asked what anaesthetic they would want for themselves in this scenario.  The evidence base for these decisions is therefore worth exploring.

A Cochrane Systematic Review published in 2016 reviewed 31 randomised trials which included 3231 participants but did not find a difference in:

• mortality at one month
• pneumonia
• myocardial infarction
• cerebrovascular accident
• acute confusional state
• the number of patients who returned to their own home
• deep vein thrombosis when LMWH was administered.

It is vital to say however that the quality of the evidence for all of these factors was considered to be very low.

In support of this, a 2018 systematic review by O’Donnell et al included randomised trials as well as observational studies and so included 202,000 patients.  This paper again found no significant difference in 30 day mortality, pneumonias, delirium, acute myocardial infarction or renal failure.  They did however suggest a small difference in length of stay favouring the spinal group but this is unlikely to be clinically significant.

What, then, can perioperative physicians and anaesthetists do to improve outcomes above the standards of care already given to older people undergoing trauma surgery (patient warming, limiting fasting, pressure area care, limiting opiates and benzodiazepines etc)?  What is clear from the 2014 sprint audit is that hypotension is significantly associated with increasing mortality regardless of anaesthetic technique – although general anaesthesia tends to cause more hypotension.  Therefore, it may perhaps be sensible to identify patients we believe may be at high risk of hypotension (cardiac medical histories, antihypertensives, undertreated hypovolaemia etc) and consider these patients for low dose spinal anaesthesia whilst perioperatively trying to limit the risks of hypotension as much as possible. 

1. National Hip Fracture Database (NHFD). Annual Report 2018.  Falls and fragility fracture audit program.  Royal college of physicians.

2. Guay J, Parker MJ, Gajendragadkar PR, Kopp S. Anaesthesia for hip fracture surgery in adults. Cochrane Database of Systematic Reviews 2016, Issue 2. Art. No.: CD000521. DOI: 10.1002/14651858.CD000521.pub3.

3. O’Donnell CM, McLoughlin L, Patterson CC, et al. Perioperative outcomes in the context of mode of anaesthesia for patients undergoing hip fracture surgery: systematic review and meta-analysis.  British Journal of Anaesthesia, 120(1): 37e50 (2018)

4. White SM, Moppett IK, Griffiths R et al.   Secondary analysis of outcomes after 11,085 hip fracture operations from the prospective UK Anaesthesia Sprint Audit of Practice (ASAP‐2). 2016.  Anaesthesia, 71: 506-514. doi:10.1111/anae.13415

NB: Although Michael McEvoy is a Cochrane Anaesthesia Research Group Dissemination Fellow he was not involved in any of the research linked to in the article and receive no funding for this role.