The sonographic Murphy sign: does analgesia matter?

Area of Science:

• Emergency Medicine
• Radiology
• Gastroenterology

Background:

• The use of analgesia before right upper quadrant ultrasound (RUQUS) for acute cholecystitis (AC) evaluation is debated.
• Opioid analgesia (OA) may potentially obscure diagnostic findings on ultrasound.

Purpose of the Study:

• To investigate the impact of opioid analgesia (OA) and non-opioid analgesia (NOA) on the sonographic Murphy sign.
• To determine the effect of OA and NOA on the diagnostic accuracy of acute cholecystitis (AC) via RUQUS.

Main Methods:

• Retrospective cohort chart review of 686 adult patients.
• Comparison of OA versus control group for AC diagnosis.
• Comparison of NOA versus control group for AC diagnosis.

Main Results:

• Opioid analgesia (OA) significantly increased indeterminate sonographic Murphy signs and false-negative AC diagnoses (7.9% vs. 3.0%).
• Non-opioid analgesia (NOA) showed no significant difference in false-negative AC rates compared to control (4.6% vs. 3.7%).
• Patients receiving OA within 30 minutes of RUQUS or low-dose OA (<4mg morphine equivalent) had higher rates of false-negative AC diagnoses.

Conclusions:

• Delaying opioid analgesia (OA) until after RUQUS or at least 30 minutes post-administration is recommended to mitigate false-negative results.
• Non-opioid analgesia (NOA) presents a safe and effective alternative for pain management during RUQUS for AC evaluation without compromising diagnostic accuracy.