The holy trinity (part 1)

By Tom Heaton

Following on from last week's post on the peri-operative management of elderly patients, I thought I would continue down a similar vein by having a look at the recent Anaesthesia article on the holy trinity (big three) of emergency surgery: abdominal aortic aneurysms (AAA), laparotomies and hip fractures. Whilst looking at these presentations in particular, the nature of the article focuses on the elderly patient with these conditions, which is understandable when you consider that it is this population in which they are most commonly seen. Given the three part nature of the article and the depth of each topic, I though it would be preferable to break it down into three different posts and keep the length of them a bit more bite-sized, starting with the ruptured AAA. If you haven’t seen the article yet yourself, it was published in the Anaesthesia supplement at the end of last year, and you can get to it through the link below:

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Emergency Surgery: The Big Three - Link

The bottom line of the article is pretty similar to that presented in the last blog post; we could probably still do more to improve outcomes for these patients. The statistics they present highlight the problem by comparing the emergency procedures to their elective ‘brothers’. The in-hospital and 30 days mortality of emergency compared to elective surgery are as follows:

• 38% versus 5% for AAA repair (not that surprising I suppose)
• 15% versus 6% for laparotomy (using colorectal cancer surgery as a comparison)
• 8.2 versus 1.2% for hip fracture repair (using total hip replacement as comparison)

The other similar trends they highlight include the reduced likelihood of these patients getting a critical care bed post op and the fact that there is significant variability in outcomes through the UK. A look at each member of the big three in detail tells us some more.

The ruptured aaa

Okay, I’m going to be honest and say I wasn’t that surprised with the fact that emergency AAA surgery has a worse outcome than elective procedures; the aorta has ruptured, it’s going to be bad. The figures are pretty dramatic though. The total ruptured AAA mortality is approximately 75%, with about 50% of patients not making it to the hospital. That still leaves a good number that make it to hospital and still don’t survive (half of those that make it through the door to save you some maths). Indeed the improvement in survival that the authors describe has been pretty mild when you think about is; just 2.5% per decade over the last 50 years. And, once again, the older you are the worse the odds become. Never mind those who don’t make it through the door, if you are over the age of 80 and you make it on to the table, the chances of survival are worse than a coin toss (a 54% 30 day mortality!).

All not great news and all reiterating some of the points that the last blog covered; these patients have less in the way of physiological reserve, are on multiple drugs, and are less likely to get level 2 or 3 care post-op, all adding up to worse outcomes. But they stress that there are rays of light in AAA care. They flag up two big positive points as:

1.      The introduction of the AAA screening programme

2.      The potential role of endovascular aneurysm repair (EVAR).

Screening for a disease has its pros and cons that I won’t talk about here (though AAA screening has a good vibe about it), but the role of EVAR looks pretty good. The IMPROVE (Immediate Management of the Patient with Ruptured Aneurysm: Open Versus Endovascular repair) trial is currently still looking at its role in managing ruptured aneurysms. However, the evidence for EVAR in elective surgery is promising when compared to the traditional open approach (risk ratio of 3.8 with a range of 3.19 – 4.68 – Nice!) with the IMPROVE trial setting itself some decent targets. 

The anaesthetic perspective

All very interesting but what about the anaesthetic bit, I hear you cry. The principles of the anaesthetic management of the ruptured AAA haven’t changed that much recently, coming down to:

• Limited fluid resuscitation until cross-clamping of the aorta
• Establish intra-arterial blood pressure monitoring pre-induction
• Non-invasive cardiac output monitoring
• Careful induction, on the theatre table with the patient draped and the knife in the surgeons hand
• Good IV access (!)

Some of the other points that the authors highlight might play a role in improved anaesthetic management of these patient include: use of cell salvage technology, availability of near-patient testing for haemoglobin, acid-base status and coagulation, and possibly the use of tranexamic acid that has been so good in other haemorrhagic conditions. Experienced anaesthetic staff is obviously another plus point for the patient but, as the authors note, you’re a lucky guy if you have a specialised vascular anaesthetist on duty when your AAA pops.  

wrap it up

That’s about it from the look at ruptured AAA management. In summary, this is still a condition that has a very poor outcome, regardless of the management provided to the patient post-event. Changes, in the form of the national screening programme and the potential of EVAR, may provide the biggest benefit for these patients, but the authors suggest there is still room for other improvement; citing the success AAA Quality Improvement Project (AAQIP) with improving elective AAA surgery outcomes.

Well thanks for reading, and I hope you are looking forward to parts 2 and 3 which should be following shortly. In the meantime I have put together some links to a few resources on the subject that you will hopefully find useful. 

Tom Heaton


http://ceaccp.oxfordjournals.org/content/8/1/11.full - A great overview of the anaesthetic side of ruptured AAA management.

http://www.frca.co.uk/article.aspx?articleid=100967 – The Anaesthesia UK stuff on elective AAA anaesthetic management.

http://emedicine.medscape.com/article/756735-overview - The always useful Medscape pages on AAA rupture

http://www.uptodate.com/contents/open-surgical-repair-of-abdominal-aortic-aneurysm - The similarly useful ‘Up-To-Date’ resources on the topic

http://www.aaaqip.com/aaaqip/index.html - The website of the AAAQIP. Some ok information but focused more on elective management.

http://www.improvetrial.org/ - The homepage of the IMPROVE trial

http://info.clinicalkey.com/blog/february-2013-podcast-abdominal-aortic-aneurysm/ - a podcast (or free transcript) on the pre-operative components of AAA

http://emcrit.org/rush-exam/ - A bit of a tenuous link to AAA but an interesting podcast


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