By Tom Heaton
Having finally got round to reading the latest AAGBI (Association of Anaesthetists of Great Britain and Ireland) guidelines, I thought they would be a great focus for the latest blog post, mainly due to (I feel) their huge relevance. A copy of the document itself is available to download below (freely distributable under one of the great Creative Commons licenses – yay!) if you haven’t had a look at it yourself yet.
| peri-operative_care_of_the_elderly_guidelines.pdf |
Peri-operative care of the elderly 2014 - Association of Anaesthetists of Great Britain and Ireland. Anaesthesia 2014, 69 (Suppl. 1), 81–98
Before going on, I think I had best start by justifying the bold statements I have just made about this article’s significance. However, I don’t think this is hard when you look at the documents opening paragraphs, or indeed when you think about your own anaesthetic practice. According to the guidelines approximately 8% of the population are over the age of 75, but they account for around 23% of all surgical procedures performed. As such this document has relevance to 1 in every 4/5 patients that you will come across. This proportion is an increase from when the last guidelines were published and it is expected that the numbers shall continue to rise. They have expanded on this fact by pointing out that recent reports (the 2010 NCEPOD and the Francis reports as examples) have shown both little improvement in outcomes for older patients over the past decade and that the healthcare culture towards older patients is ‘inadequate, disjointed and unsympathetic’. Not a very uplifting introduction but something that definitely needs highlighting. Hopefully you are now (at least mildly) intrigued and you attention is hooked and we can go for a wander through the guidelines themselves.
What’s different about the population?
Whilst this certainly isn’t a review of all the physiological differences in older patients, they have nicely pointed out the significance of changes that the ageing process causes. They describe a 1% decrease in the function of all organ system each year after the age of 40. As you can imagine, this results in multiple organ systems with a limited reserve and subsequently less ability to compensate for the stresses put on them by surgery, anaesthesia and acute illness. This is often then compounded by the polypharmacy that is so ubiquitous in this population. When you have a patient that is effectively beta blocked due to reduced beta receptor sensitivity, has impaired baroreceptor responsiveness, multiple cardiovascular drugs and the potential for significant, silent coronary artery atherosclerosis, certain aspects of your anaesthetic are going to take some extra thought. The highlighting of these features at the start of the guidelines does a good job of giving the guidance a strong sense of relevance and recaps some of the theory that may have been slightly forgotten.
What’s different pre op?
The guidelines provide certain advice on modifying the usual pre-operative management of patients in light of the many differences present in this population. Some of them are relatively obvious and broadly stated, such as advice that they are best managed by senior clinicians from a multidisciplinary background (anaesthetists, geriatricians, surgeons etc), and that senior input should be as early as possible in emergency presentations - all pretty uncontroversial.
However, being more specific they have given some good advice on important points to include in the pre-operative assessment of these patients. This includes some areas that might not be an obvious part of a general pre-op assessment; risk factors for post-op delirium, nutritional status, and risk scoring to name just a few. They also highlight the importance of close collaboration between the anaesthetic and surgical teams about the respective plans and approaches of each team. Can a minimally invasive procedure be performed that allows a minimally invasive anaesthetic to be given? What is the overall aim for this patient (return to baseline independence, palliation)?
Finally, they discuss the importance of optimisation of patients. This is especially important (and more achievable) in the elective setting, and they highlight a variety of domains where thought needs to be directed in order to prepare patients for surgical procedures. Again, whilst some of these are no different from the younger population, instead maybe just more prevalent (e.g. management of diabetes, management of anaemia), some may not be initially obvious, such as treatment of malnutrition (iron, B12 and folate supplementation, if deficient, reduces morbidity and mortality), and preparation to minimise the risk of post operative cognitive decline (POCD) and delirium. The balance of optimisation in emergency cases is also touched upon, though they direct us towards specific guidance on management of different acute pathologies. The examples they use (those of hip fracture and emergency laparotomy) are there to demonstrate that, yes the patient may be sub-optimal with regards to their comorbidities and frailty, but in these examples time to theatre is important to the outcome of these patients and optimisation should run parallel to getting the operation done and not be a delaying factor.
However, being more specific they have given some good advice on important points to include in the pre-operative assessment of these patients. This includes some areas that might not be an obvious part of a general pre-op assessment; risk factors for post-op delirium, nutritional status, and risk scoring to name just a few. They also highlight the importance of close collaboration between the anaesthetic and surgical teams about the respective plans and approaches of each team. Can a minimally invasive procedure be performed that allows a minimally invasive anaesthetic to be given? What is the overall aim for this patient (return to baseline independence, palliation)?
Finally, they discuss the importance of optimisation of patients. This is especially important (and more achievable) in the elective setting, and they highlight a variety of domains where thought needs to be directed in order to prepare patients for surgical procedures. Again, whilst some of these are no different from the younger population, instead maybe just more prevalent (e.g. management of diabetes, management of anaemia), some may not be initially obvious, such as treatment of malnutrition (iron, B12 and folate supplementation, if deficient, reduces morbidity and mortality), and preparation to minimise the risk of post operative cognitive decline (POCD) and delirium. The balance of optimisation in emergency cases is also touched upon, though they direct us towards specific guidance on management of different acute pathologies. The examples they use (those of hip fracture and emergency laparotomy) are there to demonstrate that, yes the patient may be sub-optimal with regards to their comorbidities and frailty, but in these examples time to theatre is important to the outcome of these patients and optimisation should run parallel to getting the operation done and not be a delaying factor.
What’s different intra-op?
Again the guidance stems from some of the physiological differences of this population and again some are more obvious than others. I thought some of the particularly notable bits of advice included the additional points to be included on the WHO check-list. I am personally a fan of (some) check-lists, as I think they can mitigate some of the omission errors that we are all susceptible too. As such, including a check-list point to clarify things like resuscitation status and prompting adjustment of analgesia prescription to the patient’s age and eGFR is a feature that could be both easy to implement and beneficial.
Other components are perhaps more obvious but still very valid. Careful adherence to temperature maintenance is one they particularly flag up, but they also describe some of the ways that increased use of invasive arterial blood pressure monitoring, cardiac output monitoring and careful assessment of depth of anaesthesia (either through BIS, age-adjusted MAC calculations or TIVA software) can potentially minimise complications. It would have been great to have included some specific advice on fluid management in this patient group, but as they point out (and as is the problem for much of anaesthetic management in the older patient) there isn’t clear guidance or evidence out there yet (more on this later). This shortcoming continues into the guidance on the choice of anaesthetic technique itself, with the advice generally being; it’s up to you to tailor the technique to your patient.
Other components are perhaps more obvious but still very valid. Careful adherence to temperature maintenance is one they particularly flag up, but they also describe some of the ways that increased use of invasive arterial blood pressure monitoring, cardiac output monitoring and careful assessment of depth of anaesthesia (either through BIS, age-adjusted MAC calculations or TIVA software) can potentially minimise complications. It would have been great to have included some specific advice on fluid management in this patient group, but as they point out (and as is the problem for much of anaesthetic management in the older patient) there isn’t clear guidance or evidence out there yet (more on this later). This shortcoming continues into the guidance on the choice of anaesthetic technique itself, with the advice generally being; it’s up to you to tailor the technique to your patient.
What’s different post-op?
The authors leading point about post-operative care is that these are patients with higher rates of morbidity and mortality and thus are perhaps most suitable for level 2 or 3 critical care post-operatively. The advice they give is for anyone with a predicted mortality of over 10% to receive this care, and that age by itself is not a valid exception to this; though they recognise the gaping discordance between the demand for and supply of critical care beds that is unlikely to change any time soon. They link this point back to the preceding components of the review and how the anaesthetist can minimise this post-operative risk by careful consideration of the risk factors for their patient and with implementation of appropriate management (e.g. cautious, guided fluid therapy). This can also be linked back to areas such as the decision making about the nature of the surgical procedure itself. Can a temporary procedure e.g. stenting of a bowel obstruction, be used rather than a major one (e.g. laparotomy) to allow proper optimisation of the patient for a future date?
There are a few other points of recommendation here that can lead back to the choice of anaesthetic. Ideas such as using multi-modal analgesia (including nerve blockade) to reduce NSAID and opioid use and subsequently try and reduce post-op delirium, NSAID related complications, and improve post op nutrition through better oral intake. They also flag up that post-op pain and delirium are both complications that can go undiagnosed and unrecognised unless they are specifically sought, advising that this should be done from as early as recovery.
There are a few other points of recommendation here that can lead back to the choice of anaesthetic. Ideas such as using multi-modal analgesia (including nerve blockade) to reduce NSAID and opioid use and subsequently try and reduce post-op delirium, NSAID related complications, and improve post op nutrition through better oral intake. They also flag up that post-op pain and delirium are both complications that can go undiagnosed and unrecognised unless they are specifically sought, advising that this should be done from as early as recovery.
anything else?
I think the only other point of note from the review comes from the authors closing paragraphs which highlight the absence of good quality evidence to provide guidance in this particular population. This is probably not surprising after reading the guidelines through, as it is almost entirely comprised of advice along the lines of, ‘You could do this…’, rather than advice that is followed by strong evidence of an improvement of outcome if it is implemented. I hope you will agree with me that this doesn’t negate the usefulness of much of the guidance that they provide, though it certainly puts some limits on it. As such, I am unsure how far we can go to making the improvement to outcomes for these patients that the authors highlight has been missing at the start of the paper. Expert opinion has its role, but I think we may need more than that to make measurable improvements to patient care, especially in an already complicated population. But I suppose we can only work with what we have, and I certainly found a lot of useful advice to get on with here. Again, if you haven't had a look through the guidelines yet I'd definitely recommend it. This is a patient population that we will encounter frequently and for whom we can probably do more for.
Many thanks for reading and I hope it has been of some interest to you at least. As always, please leave your feedback and comments as they are always welcome.
Tom Heaton
Many thanks for reading and I hope it has been of some interest to you at least. As always, please leave your feedback and comments as they are always welcome.
Tom Heaton
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