RLQ Pain in Pregnancy (the sequel)

A few weeks ago Rob Orman (ER Cast) did a great interview with Dr Ingrid Lim at ACEP which looked at the diagnosis of the possible appendicitis in pregnant women.  Go and check out the 20 minute podcast at ERCast (click here) , then come back here to hear the sequel….

There are some great pearls that came out of this talk – HCG uses and interpretation (my review of some old literature), the role of US and CT as diagnostic tools in pregnancy and when to operate?  But, after this I had some acute onset confusion – as an ED doc your job is to make the diagnosis, try and sell it to a surgeon – then off to OT or not.  But what are the risks of going to do an exploratory laparoscopy / laparotomy in the common scenario where you are just not sure, don’t think a CT is worth the risk or you have no imaging available???

So after Rob O poked the fate Gods in the eye with a stick I ended up seeing 2 pregnant ?appendixes in one shift!  Thanks Rob.  So I spent the time it takes to “fast a pregnant lady” looking at the evidence, reviews and opinion that is out there in the surgical literature.  And now I am even more confused – more so than after listening to the average SMART EM podcast!  So many twists and turns – David Newman, can you help me?

All the evidence is retrospective analysis – ethics make it tough to do it any other way.  There are a couple of really big registry studies that give a big picture of the problem:

McGory et al analyzed over 3000 pregnant women undergoing appendectomy around the turn of the millenium and discovered a few points:

  • The rate of “negative appendix” was higher in pregnant vs. non-pregnant women (23% vs 18%; p <0.05) – I am gonna guess this is due to the technical difficulty with US in pregnancy and the reluctance to do a CT – so more going to OT with less ‘diagnostic’ work up.
  • The rate of perf / complex appendix was the same as in the general population ~ 30%
  • If you looked at Fetal loss and preterm delivery (bad, patient oriented outcomes) – there was an interesting pattern:
    • It was high in those with perforation / complex appendix – as you might expect – around 6% fetal loss
    • The women with simple appy, ie. not perfed, did better – around 2 % fetal loss
    • The surprise was that women with “negative appendix” – no disease had a rate of fetal loss slightly greater than the ‘simple appendicitis’ group
    • I have no idea why, maybe their pain was related to a uterine / ovarian problem – so the appy was an innocent bystander?

So the conclusion is that you need to decrease your “negative appy” rate in pregnant women – which I assume means doing more CTs and USS.  Watchful waiting may not be a good option – because they do a lot worse if they perforate and get systemically unwell etc.  I think the risk of CT (about 2x rate of childhood cancers) is small when you compare it to the risk of fetal loss (6+%)  BUT…. you are asking a woman to compare apple seeds and oranges – I think this is so dependent on the individuals world view, beliefs and maybe religion that it is just too hard to make a sweeping statement.  HMMMM…difficult…

 

So lets say – you dont have a CT (or patient refused it), the USS is inconclusive, but you are 66% sure on clinical grounds with a bit of a white-cell bump that is is an appendicitis.  You sell it to the surgeon, she says:

“well, OK it might be.  I’ll stick in a laparoscope and have a look, then proceed with appy if positive…  Oh, and then I can look and see if there is anything else going on at the same time”   Sounds like a sweet plan on first hearing it – but what does the evidence show?

Dr Walsh and colleagues in the UK did a review of the data (Int Jour Surgery) and showed more telling points in this debate:

  • Rates of fetal loss at laparoscopic appendicectomy were 6%, and significantly worse than open appendicectomy.
  • Fetal loss was greatest in the complex / perforated appendix group as with McGory
  • Fetal loss was the same for simple appendicitis as the “negative appy” groups – as in McGory
  • Showed the same higher “negative appendectomy” rate – around 27% – in non-pregnant women
  • Tocolytic agents did not make a difference in rates of preterm labour etc
  • “entry related complications” – (stabbing the uterus?) were low, but you should go with open Hasson technique – not the Veress needle.

So where does this leave us?  The data suggests a few points to me – maybe you can read it differently:

  • Lowering the “false appendicitis” at surgery will reduce the fetal loss / complications – so you should be doing all the tests, including USS and maybe CT to reduce the risk of unnecessary operations.  Admittedly – this is far from a perfect science – there will always be some ‘lily white’ appys.
  • Cast you diagnostic net fine and wide – get a good urine off for microscopy – the commonest “final diagnosis” in the false appendix patients was pyelonephritis
  • If you are going to operate – maybe minimalism is the best bet – minimal anaesthetics drugs, shortest sleep time, maybe open is better than laparoscopic techniques for these women?
  • Of course if you go in with a gridiron incision – you might miss the other pathology – eg. torsion of ovary. So here is a downside there too.
Let me know if you have another way of thinking about all this?  KNow of any good studies that change the strategy?  I would love to know…
Casey
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