Analgesia for Acute Abdominal Pain in the ED

Author: Ken Young, MS4
Loyola Stritch School of Medicine

While this post may involve less new information and more beating of dead horses, two recent experiences have reminded me of what I found to be an interesting concept in medicine — the belief that pain medications interfere with diagnosis in acute abdominal pain.

Recently, a friend of mine had a case of appendicitis, presented to his local ED, and was promptly told he could not be given any pain medication because it would “mask his abdominal exam.” Shortly after this, while studying for my final exam of medical school, I read the following in a case study on abdominal pain:


Narcotics should be used cautiously to avoid masking the pain and delay further assessment and decision making process. [1]

While cautious use of narcotics in the ED is something we should all strive for (and material enough for many more blog posts), the reasoning provided reflects old, anecdotal thinking that has been extensively studied and largely disproven. A great review published earlier this year in the European Journal of Pain tackled the subject, and a “Medical Myths” article from 2000 delved into some of the reasoning behind the practice. While both articles are worth a read, here are some highlights:

• The concept of withholding pain medication before a diagnosis was established dates back to a 1929 book, Early Diagnosis of the Acute Abdomen (notably published before modern lab studies and CTs). [2]

• Patient satisfaction with preoperative pain management ranges from 40-60%, while post-operative satisfaction is over 90%. [3]

• Several studies, including a Cochrane review from 2007 and 2011, confirm that pain management before diagnosis — regardless of what the diagnosis turns out to be — is appropriate. The Cochrane review looked at eight RCTs and concluded that opioid analgesia before diagnosis neither increased the risk of misdiagnosis nor of inappropriate treatment, and may actually facilitate an easier exam. [4]
• Concerns that opioids can interfere with a patient’s ability to give informed consent for a surgical procedure are largely unfounded. On the contrary, withholding adequate analgesia could potentially interfere with patient’s informed consent in two ways: 1) Through severe pain impairing judgment, and 2) Causing patients to believe they will only be treated for pain if they agree to surgery. [2]

The topic of Oligoanalgesia overall is fantastically summarized in this Short Coats in EM blog post from 2012, which links to many other resources and studies. [5]

While opioids should be used appropriately and cautiously, do not be afraid to treat your patients’ abdominal pain due to fear of delaying or preventing an accurate diagnosis.


References
1. Abdominal Pain. Alliance for Academic Internal Medicine. http://www.im.org/toolbox/curriculum/CDIMsubinternshipCurriculum/Pages/TrainingProblemsStudentGuide.aspx. Accessed May 2014.

2. Brewster GS, Herbert ME. Medical Myths: Analgesia should not be given to patients with acute abdomen because it obscures the diagnosis. Western Journal of Medicine. 2000; 172:209-210. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1070812/. 

3. Falch C, Vicente D, Häberle H, et al. Treatment of acute abdominal pain in the emergency room: A systematic review of the literature. European Journal of Pain. 2014 Jan 22. doi: 10.1002/j.1532-2149.2014.00456.x. [Epub ahead of print]

4. Manterola C, Vial M, Moraga J, Astudillo P. Analgesia in patients with acute abdominal pain. Cochrane Database. Jan 19;(1):CD005660. doi: 10.1002/14651858.CD005660.pub3.

5. FOAM: Fighting Oligoanalgesia And Meanness. The Short Coat. http://shortcoatsinem.blogspot.com/2012/10/foam-fighting-oligoanalgesia-and.html. Accessed June 5, 2014.