Spinal anaesthesia is better for hip fracture patients than general anaesthesia, OK?

There – I’ve said it. Nailed my flag to the mast. Now, I’m going to try and persuade you why this is the case, even though there’s not been any good evidence published to support this.

But first, two stories.

I grew up listening to my Grandpa Sid telling tales of his childhood adventures, his escapades in the RAF (good navigator, hopeless rear gunner) and his demob job as an engineer in a big hotel. He bought me my first pint of beer (at 14!) and helped fund me through medical school.

When he was in his 70’s he needed a large inguinal hernia repaired. Mildly hypertensive normally, he was mildly hypotensive throughout his 2hr operation under general anaesthesia + nerve block, but not to the extent that he needed vasopressors. He had a comfortable inpatient stay that first night. When I visited him the next day, however, he was delirious, reliving his rescue from the North Sea after being shot down during WW2. There was no particular cause found, the delirium resolved over a few days and he was discharged, but ‘he was never quite the same man again’.

Sound familiar? Certainly, talking to other people about their elderly relatives, it’s surprising how often a similar story gets told.

Contrast this with my Auntie Glad. She’d been at school with Amy Johnson, met Thomas Edison and been a concert pianist. In 2015, aged 112, she became the UKs oldest living person – and shortly afterwards became the UK’s oldest hip fracture patient, having fallen out of bed. Otherwise fit and well, she had a spinal anaesthetic without sedation, and good blood pressure control throughout her hour-long hemiarthroplasty. Her anaesthetist chose this method ‘to avoid respiratory depression and haemodynamic instability’. She recovered, celebrated her 113th birthday, and at the time of writing is still the UK’s oldest living person, more than 6 months after her operation.

Again, a familiar story – the anaesthetist avoiding general anaesthesia and sedation in an elderly or sicker patient to try and improve their postoperative outcome.

These are anecdotes, of course, but there is evidence from NHFD and ASAP data that anaesthetists do change their practice for older and sicker hip fracture patients, preferring to give spinal rather than general anaesthesia more often than they do to younger, fitter hip fracture patients.

It’s not clear why this is the case from observational data, but perhaps anaesthetists suspect that spinal anaesthesia is generally ‘better’ for older, sicker patients.

Published evidence supports these suspicions. Agreed, observational and RCT data does not show any significant difference in mortality after spinal or general anaesthesia, but are we really surprised by that? That a two-hour episode of anaesthesia should determine whether patients are more likely to die 720 hours (ie 30 days) later? A patient could be killed in a road traffic accident on the way home from hospital after hip fracture surgery on day 20, for example; any number of reasons for death can occur between surgery and 30-days, yet be unrelated to anaesthesia. The further away you measure the outcome after anaesthesia, in other words, the less likely you are to be measuring any effect of the anaesthetic itself.

Also, mortality (and morbidity) data compare ‘spinal’ with ‘general’ anaesthesia, and both are very broad churches. ‘Spinal’ – with sedation/GA? With nerve block? Low-dose? With opioids? General – with nerve block? Ventilated? Paralysed? Depth adjusted? Brain monitored? Inhalational? It’s meaningless to compare the two unless we define what we’re comparing.

Published meta-analyses, however, do point to lower morbidity after spinal anaesthesia compared to general anaesthesia, however. These findings are not statistically significant, but again, are not able to account for the effects of sedation given with spinal anaesthesia. Respiratory, myocardial and cognitive complications are fewer. There’s still a lot of research needs doing in this area, though, particularly looking at ‘anaesthetic’ complications – pain, hypotension – but also early ‘rehab’ complications – remobilization, delirium.

Perhaps we need to think more about what anaesthesia is trying to achieve for hip fracture patients, and view our practice as merely a component of their early recovery.

In the UK, orthogeriatricians are getting very good at delivering hip fracture patients to theatre as ‘fit’ as possible for anaesthesia and surgery. We need to get into the habit of returning the favour, so that orthogeriatricians, nurses and physiotherapists can rehabilitate patients as quickly as possible after surgery, and return them home.

To do this, I think it helps to have a mental image of what our patients should look like in the recovery room straight after surgery. I think that a hip fracture patient that is ‘ready to rehab’ should be: sitting up, able to speak coherently, comfortable, disconnected from fluids and oxygen, and drinking a cup of tea – ‘normalised’, in other words. Never underestimate the restorative powers of a cup of tea in the recovery room!

So how can anaesthetists enable this ‘enhanced recovery for hip fracture’? What limited evidence there is supports what we already do for elective total hip replacement, but modified for an older, sicker patient population: give regional anaesthesia, use nerve blocks, give some fluids and minimize the use of centrally active drugs.

It’s that last point that we’re interested in here. We get the idea that we should try and avoid opioids in the elderly because of their (neurocognitive) side-effect profile. Why, then, are we any less certain that other neuroactive anaesthetic drugs are any less likely to cause neurocognitive side-effects? I agree that research is inconclusive about this, but it seldom involves patients of the age, comorbidity and preop cognitive status of the hip fracture population, and usually fails to account for the effects of other variables on neurocognitive outcome. It’s also difficult to workout whether it is the drugs themselves, or some their pharmacodynamic effects (eg hypotension) that cause problems.

Avoiding these problems is simple, of course – don’t give centrally acting drugs: in other words, avoid general anaesthesia, particularly for older, sicker, cognitively impaired patients. If you need to give a GA, use the least possible – ie monitor the depth of anaesthesia.

But also avoid or minimize sedation if you give a spinal anaesthetic. It’s not surprising that outcomes are usually found to be similar between ‘spinal’ and ‘general’ anaesthesia, if the vast majority of the ‘spinal’ group are also receiving sedation, often to the depth of general anaesthesia. Effectively, we are comparing two types of ‘general’ anaesthesia, one type of which is given with additional spinal anaesthesia.

It’s interesting the responses that you get if you ask various medical professionals what they’d prefer to have if they needed a hip fracture repaired. Anaesthetists are virtually unanimous in wanting spinal anaesthesia, and often qualify this with ‘without sedation’. Orthogeriatricians usually prefer spinal anaesthesia because they think recovery is quicker, even if they’re less certain whether discharge times or mortality are improved. Nurses and physiotherapists invariably prefer spinal anaesthesia because they have to deal with the nausea, vomiting, delirium and delayed mobility they perceive to be more common after general anaesthesia. Even the vast majority of orthopaedic surgeons I’ve asked, who often think that a spinal anaesthetic takes a frustratingly long time to administer compared to a general anaesthetic (it doesn’t), would prefer spinal anaesthesia.

If neuroactive drugs are probably not great for elderly hip fracture patients, then why do we give so many general anaesthetics to them? Is it for the patients’ benefit … or our own? Sure, we are more familiar with general anaesthesia. General anaesthesia is very safe. General anaesthesia keeps patients still. General anaesthesia means we don’t have to talk to the patient, so we can do other things … . And sure, spinal anaesthesia for hip fracture patients – particularly those with agitated dementia – can be challenging. But I do wonder whether using chemical means to keep patients still for surgery is just deferring a poorer outcome for someone else to have to deal with in the days after the operation. Rather than general anaesthesia or heavy sedation, what is needed as much as anything else is analgesia: hip fractures often hurt – give a spinal, take the pain away and even the most agitated of patients usually goes to sleep, catching up with what they missed the night before.

I think things are changing, though. Recent NHFD data show that the proportion of patients given spinal anaesthesia is increasing year after year. Maybe the message about the relative benefits of spinal anaesthesia is getting through. More likely, anaesthetists are seeing the patient outcome benefits of enhanced recovery programs for elective hip replacements and so are becoming more comfortable managing awake/lightly sedated patients undergoing such major surgery, providing ‘enhanced recovery for hip fracture’ as a result.

In summary? General anaesthesia and sedation: if you don’t need to do it, don’t do it. Play patients films on an iPad during spinal anaesthesia. Or music on an iPod. Or talk to them – they’ve lived a long time and have got great stories to tell!