Andrew Grimes, MS4
The Article: Matthew Fields, J., et al. "Accuracy of Point‐of‐care Ultrasonography for Diagnosing Acute Appendicitis: A Systematic Review and Meta‐analysis." Academic Emergency Medicine 24.9 (2017): 1124-1136
The Idea: The use of ultrasound to diagnose appendicitis is well established in medical practice. With the expanding availability, training, and application of ultrasound, the use of point of care ultrasound (POCUS) has emerged to diagnose appendicitis, particularly in the setting of an emergency department. In addition, the use of POCUS for the diagnosis of appendicitis is largely favorable due to its safety, cost-effectiveness, reduction of radiation exposure, and decrease length of time stay. The study is the first systematic review and meta-analysis to examine the accuracy of nonradiologist physicians; including emergency medicine, surgery, and gastroenterologists; in accurately diagnosing appendicitis with the use of POCUS.
The Study: This study was a systematic literature review and meta-analysis involving 21 articles published between January 1980 – May 2015 from multiple countries including the United States, Switzerland, China, Japan, Italy, Korea, Iran, and Taiwan.
Inclusion Criteria: Articles published in English with a focus on diagnosing acute appendicitis by ultrasound by nonradiologist physicians, and reported data for calculation of sensitivity and specificity.
Exclusion Criteria: Excluded articles included those with no reported data, data including more than 50% of patients that were pregnant, sample sizes less than 10, and those studies using the use of animals or cadavers.
Primary Endpoints: The accuracy, including sensitivity and specificity, of diagnosing acute appendicitis in nonpregnant patients of any age by nonradiologist physicians
Secondary Endpoints: Subgroup analysis of the accuracy, including sensitivity and specificity, of Emergency Medicine physicians compared to Surgery, GI and Radiology physicians.
Results: Out of 6,792 potential relevant articles, 21 articles were including according to the stated criteria. The 21 included articles range from 1996 – 2015 within a hospital ED setting, one inpatient/outpatient setting, and one inpatient surgical setting. Included articles were studies published in countries including the United States, Switzerland, China, Iran, Japan, Korea, Taiwan, and Italy. The raw, weighted evaluation of data revealed a sensitivity of 91% and specificity of 97% of diagnosing acute appendicitis with the use of POCUS. When controlling for methodologic quality and reporting, the sensitivity was 92% and specificity of 96%. A subgroup analysis of Emergency Medicine reported a sensitivity of 80% and specificity of 92%. Additional subgroup analysis of pediatric patients revealed a sensitivity of 89% and specificity of 97% for Emergency Medicine physicians and a sensitivity of 96% and specificity of 92% for non-Emergency Medicine physicians. For nondifferentiated patients based on age (including pediatric and non-pediatric patients) Emergency medicine physicians had a sensitivity of 76% and specificity of 89%. For non-Emergency Medicine physicians, a sensitivity of 93% and specificity 99%.
The Takeaway: This systematic review reveals and supports the use of POCUS by nonradiology physicians in the diagnosis of acute appendicitis. Review of the data reported in the 21 included articles reveals a high accuracy, high sensitivity, and high specificity in the diagnosis of acute appendicitis. In addition, this review supports the use of POCUS in cost-effectiveness, safety, shortening of length of stay, and reduction of radiation exposure, most notably in pediatric patients. Initial analysis of the data reported in this review shows that in the subgroup analysis, Emergency Medicine physicians have a lower sensitivity (80%) and lower specificity (92%) compared to the sensitivity and specificity of all included physicians, 92% and 96% respectively. In addition, the data reveals that particularly in pediatric patients, Emergency Medicine physicians have a lower sensitivity (89%) and lower specificity (97%) compared to non-Emergency Medicine physicians, 96% and 92% respectively. However, further analysis of the data reveals several limitations and flaws to the study which greatly influences the data and results of this review. The studies ranged from 1996 – 2015 which covers a wide range in time in which many developments and training of ultrasound use have occurred. Most notably, this review did not and could not control for level of expertise reported by the studies included and the POCUS operators. The majority of nonradiologist physicians included Emergency Medicine physicians, and the reported level of expertise and training ranged from a 4-hour course to >12 months of experience. Therefore, the lack of control for level of expertise and training in the reported data greatly skews the reported accuracy of diagnosing acute appendicitis with POCUS for the reported Emergency Medicine physicians. Overall, this data does support the utility of POCUS use in the diagnoses of acute appendicitis with great accuracy, sensitivity, and specificity by nonradiologist physicians.