Simulation Cases Cliff's Notes - Appendicitis in Pregnancy

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Every month we summarize our simulation cases. No deep dive here, just the top 5 takeaways from our high fidelity simulation case.




 

 
 
pregnant+abd+pain.jpg
 
 

Acute appendicitis in

pregnancy

 

1. Pregnancy may sometimes seem like a morbid state (nausea, vomiting, abdominal pain, GERD, constipation, increased nephrolithiasis), but be careful to merely attribute your patient’s symptoms to pregnancy.

 

2. Beware of the higher incidence of atypical presentations for appendicitis during pregnancy.

  • While right lower quadrant pain (RLQ) is still the most common presentation of appendicitis in pregnant patients, be aware of atypical presentations[1-2]:

    • Retrocecal appendicitis (dull ache in flank)

    • Pain located more cephalad as the uterus enlarges (causing mid or right upper quadrant pain)

 
http://humananatomylibrary.com/wp-content/uploads/2016/07/female-anatomy-pregnancy-diagram-reproductive-system-anatomy-amp-physiology.jpg

http://humananatomylibrary.com/wp-content/uploads/2016/07/female-anatomy-pregnancy-diagram-reproductive-system-anatomy-amp-physiology.jpg

 
 

3. For the atypical presentation, have a solid imaging strategy that minimizes radiation to the fetus.

  • Providers must weigh the risk of delayed diagnosis and rupture with the risk of exposing the fetus to radiation and the stress of a negative appendectomy

  • Graded compression ultrasonography (GCU) should be your first choice (67-100% sensitivity) [3-4]

    • More technically difficult in the third trimester

    • The wide variation in the reported diagnostic performance of GCU for appendicitis during pregnancy is due to multiple factors such as gestational age, maternal body mass index (BMI), and the skill of the operator

  • MR after inconclusive ultrasound is the preferred next test as it avoids the ionizing radiation of CT

    • MR has been shown to have a 97% sensitivity, 99% specificity [5-7]

    • Gadolinium is not routinely administered because of both demonstrated and theoretical fetal safety concerns

  • If MR is not available or there is a prolonged wait time, consider CT abdomen/pelvis (especially in later trimesters) with surgery/ob consult (85% sensitivity, 97% specificity)[8]

 

4. Know your numbers.

  • It is believed you need 50 mSV of cumulative ionizing radiation during pregnancy to induce a fetal abnormality [9]

  • A CT abdomen/pelvis is 13-15mSv (below the 50mSV threshold)[9]

  • The risk of fetal loss is increased when:

    • The appendix perforates

      • Fetal loss with perforation 36% vs 1.5% fetal loss without perforation[10]

    • Generalized peritonitis or a peritoneal abscess is present[11]

      • Fetal loss 6% versus 2% without

      • Early delivery 11% versus 4% without

  • Following a negative appendectomy, premature delivery and fetal loss are seen in 10-26%[11,12] and 3-7.3% [11-13] respectively.

 

5. Phone your friends for help (Ob/gyn and surgery).

  • Working up appendicitis in the pregnant patient is a team sport - get your colleagues involved early to help with your workup.

 

Written by Jeffrey A. Holmes, MD

Peer Reviewed by Jason Hine, MD

References

1. Mourad J et al. Appendicitis in pregnancy: New information that contradicts long-held clinical beliefs. Am J Obstet Gynecol 2000;182:1027-1029.[Pubmed]

2. Tracey M, Fletcher HS. Appendicitis in pregnancy. Am Surg 2000;66:555-559; discussion 559-560.[Pubmed]

3. Lim HK et al. Diagnosis of acute appendicits in pregnant women: value of sonopraphy. AJR Am J Roentgenol. 1992 Sep;159(3):539-42.[Pubmed]

4. Williams R, Shaw J. Ultrasound scanning in the diagnosis of acute appendicitis in pregnancy. Emerg Med J 2007;24: 359-360.[Pubmed]

5. Oto A et al. MR imaging in the triage of pregnant patients with acute abdominal and pelvic pain. Abdom Imaging 2009;34:243-250. [Pubmed]

6. Duke E et al. A Systematic Review and Meta-Analysis of Diagnostic Performance of MRI for Evaluation of Acute Appendicitis. AJR Am J Roentgenol 2016; 206:508.[Pubmed]

7. Kave M et al. Pregnancy and appendicitis: a systematic review and meta-analysis on the clinical use of MRI in diagnosis of appendicitis in pregnant women. World J Emerg Surg 2019; 14:37.[Pubmed]

8. Basaran A, Basaran M. Diagnosis of acute appendicitis during pregnancy: a systematic review. Obstet Gynecol Surv 2009; 64:481.[Pubmed]

9. K.S. Toppenberg et al. Safety of Radiographic Imaging During Pregnancy. Am Fam Physician. 1999 Apr 1;59(7):1813-1818.[Full Access Article]

10.  Babaknia A et al. Appendicitis during pregnancy. Obstet Gynecol 1977; 50:40. [JAMA Abstract]

11. McGory ML, Zingmond DS, Tillou A, et al. Negative appendectomy in pregnant women is associated with a substantial risk of fetal loss. J Am Coll Surg 2007;205:534-540.[Pubmed]

12. K. Ito et al. Appendectomy in pregnancy: evaluation of the risks of a negative appendectomy. Am. J. Surg., 203 (2012), pp. 145-150[Pubmed]

13. C.A. Walsh, T. Tang, S.R. Walsh Laparoscopic versus open appendectomy in pregnancy: a systemic review Int. J. Surg., 6 (2008), pp. 339-344. [Pubmed]

14. Silvestri MT et al. Morbidity of appendectomy and cholecystectomy in pregnant and nonpregnant women. Obstet Gynecol 2011; 118:1261. [Abstract]

15. Mazze RI, Kallen B. Appendectomy during pregnancy: A Swedish registry study of 778 cases. Obstet Gynecol 1991;77: 835-840.[Pubmed]

16. Mahmoodian S. Appendicitis complicating pregnancy. South Med J. 1992 Jan;85(1):19-24.[Pubmed]