Learning Objectives: After reading this article, the physician should be better able to:
- Classify the evidence that opiate analgesics given for acute abdominal pain may change findings on examination but not necessarily for the worse.
- Relate the absence of evidence that opiate analgesics given for acute abdominal pain cause any change in surgical management errors.
- Categorize the practical benefits and advantages of early control of acute abdominal pain in the emergency department.
Article from the 2010 LLSA Reading List
Do Opiates Affect the Clinical Evaluation of Patients with Abdominal Pain?
Ranji SR, et al
You are evaluating a 25-year-old man with acute abdominal pain in the ED. He has stable vital signs, but is febrile and reporting vomiting, anorexia, and gradual onset abdominal pain that was initially periumbilical but now is in the right lower quadrant. He has no urinary symptoms, no past medical or surgical history, and takes no medications. He is lying still on the gurney because movement worsens the pain. He has moderate guarding and rebound on examination, and is complaining of 9 out of 10 pain.
Suspecting a case of acute appendicitis, you call the surgeon on call who is in the last hour of an operative case. She agrees with your assessment, but requests withholding pain medicine until she can examine the patient herself. You remind the surgeon of the significant pain from which your patient is suffering, but she cautions that analgesics may affect her clinical assessment. What do you do? This meta-analysis from the Rational Clinical Examination series of JAMA attempts to help shed some light on this far too common clinical dilemma.
Summary: This meta-analysis from the Rational Clinical Examination series of JAMA attempts to help shed some light on this far too common clinical dilemma. Citing data from the Centers for Disease Control and Prevention, this article states that abdominal pain is the most common chief complaint in the emergency department (www.cdc.gov/nchs/data/ad/ad358.pdf), and a good portion of these patients require surgical consultation.
The authors begin by reviewing the embryonic development of pain nerve fibers and the pathophysiology of acute abdominal pain. Unmyelinated afferent nerve fibers mediate the vague, deep, visceral pain often noted early in acute abdominal disease. Later, as the disease progresses to involve the peritoneum, larger myelinated nerve fibers convey sharper, more easily localized pain. Finally, when the peritoneum becomes frankly involved, classic peritoneal signs such as motion tenderness, guarding, and rebound occur.
The authors of this study try to answer two questions related to opiates and acute abdominal pain. Do opiates alter the physical examination? And do opiates result in bad surgical outcomes, specifically delays in surgery or unnecessary surgery?
For this meta-analysis, the literature was scanned for articles related to abdominal pain, surgical diagnoses related to the abdomen, and analgesia. Almost 500 articles were initially identified, but final analysis was limited only to clinical trials comparing opiods with placebo for acute abdominal pain. Pooled data from nine trials point to a statistically significant change in physical exam findings after the administration of opiates for abdominal pain (RR=1.55; 95% CI [1.02 to 2.36]). Data from seven other trials point to no statistically significant increase in surgical errors due to the administration of opiates for abdominal pain (+0.1% absolute increase; 95% CI [−3.6% to 3.8%]).
The authors are quick to point out many methodological limitations of the individual studies selected in this meta-analysis and the potential for error in their conclusions. For example, some of the studies did not use blinded examiners, potentially introducing bias if the examiner knew what, if any, pain medicine a patient received. Some studies used the same examiner for serial exams while others compared the exam findings of two different physicians (emergency physician and surgeon). Finally, opiate dosing was variable, and indeed three of the included studies in the analysis reported no improvement in patients' pain, suggesting inadequate analgesia was given.
The article concludes that opiate administration may alter physical examination findings, but emphasizes that these changes are not significant because they result in no increased errors in surgical management. The article recommends early administration of opiate analgesia as needed to patients presenting to the emergency department with acute abdominal pain.
Comment: We were all warned in medical school during surgery rotation that analgesics can mask important exam findings like peritoneal signs. For me this lesson came the day after I became acquainted with other favorite surgical dogma: All patients require a rectal exam, the real reason surgical residents are always so busy.
According to ACEP physicians surveyed in 2000, 76 percent of emergency physicians chose to withhold opiate analgesics for the acute abdomen until the patient was examined by a surgeon. (Am J Emerg Med 2000;18: 250.) Soon after this paper came out, I received my first administrative task as an academic emergency physician to review interdepartmental policy regarding the administration of analgesics prior to surgical consultation. Surgeons had expressed concern their assessments were being compromised due to analgesics being administered in the ED. Optimistic I could use their concern for our benefit as a means to correct prolonged consultation delays (another problem at the time), we agreed to contact the surgeon first, with the understanding they would examine the opiate-virgin belly immediately. Although a good strategy in principle, ultimately it failed because surgical residents always seemed to be unavailable or in the operating room while laboratory tests were pending, only to magically appear when our patient's white blood cell count came back. The final draft of our interdepartmental policy allowed for short-acting opiates (fentanyl) to be administered if bedside surgical assessment could not be done within minutes of initial phone consultation. A few months later, surgeons asked to revise the policy again for a completely different reason. They were now uncomfortable consenting patients for emergent operative procedures while under the influence of opiate analgesics. Fortunately, common sense prevailed when we pointed out the potential liability of consenting patients under duress: “Just sign here, and you can have pain medicine.”
Nine years later, practice has changed dramatically at our institution, and although the policy still exists, it is rarely referenced, enforced, or practiced. Opiate analgesics are freely given by the emergency physician for acute abdominal pain, patients appreciate it, and consultants rarely complain. So what has led to this change in practice? It's difficult to say.
There isn't much in the literature on the effect of opiate analgesic use on obtaining patient history. Rarely a patient becomes nauseated, overly sedated, or hypotensive from opiate analgesics administered in the ED, but the vast majority of the time, early analgesia clearly benefits the patient and your interaction with them rather than causing harm. Patients who sometimes have been waiting for hours to see you are happy to finally get some pain relief. They also are able to focus better on you and your questions rather than their relentless pain. EPs learn from years of experience that administering opiates early to patients with severe back spasms or renal colic reduces the moaning, crying, and sometimes sheer agony that interferes with or prohibits you from getting an adequate history. And, unlike some of previously mentioned “principles” learned during medical training, the one about most of the diagnosis being in the history is still embraced my most seasoned physicians.
Finally, analgesics seem to be effective in filtering out the noise from the pertinent examination findings. This meta-analysis found a statistically significant change in examination findings after the use of opiate administration for abdominal pain, but each study didn't necessarily qualify if the changes were potentially good (i.e., voluntary muscle relaxation, allowing for better localization of pain) or bad (masking frank peritonitis) or just different. If this difference doesn't result in any errors in management, then either way, it probably doesn't matter. But if real-world experience indicates this change is probably for the better, it may be.
In summary, control your patient's abdominal pain and control it early. You're likely to find you get a better history from a happier patient. Exam changes do occur after analgesics are administered, but they aren't necessarily changes for the worse, and there is no evidence that these changes lead to any errors in surgical management. Hopefully explaining your line of reasoning to the consulting surgeon is enough to change her practice. If not, you may have to settle for knowing that the preponderance of literature is on your side, and that deeply ingrained dogmas are difficult to change. Now onto the next battle: convincing the radiologist that opiates before an ultrasound isn't necessarily a bad thing.
CME Participation Instructions
To earn CME credit, you must read the article in Emergency Medicine News, and complete the evaluation questions and quiz, answering at least 80 percent of the questions correctly. Mail the completed quiz with your check for $12 payable to Lippincott Continuing Medical Education Institute, Inc., Two Commerce Square, 2001 Market St., Third Fl., Philadelphia, PA 19103. Only the first entry will be considered for credit, and must be received by Lippincott Continuing Medical Education Institute by April 30, 2011. Acknowledgment will be sent to you within six to eight weeks of participation.
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