Test Characteristics of Emergency Medicine-Performed Point-of-Care Ultrasound for the Diagnosis of Acute Cholecystitis: A Systematic Review and Meta-analysis.

Acute cholecystitis accounts for up to 9% of hospital admissions for acute abdominal pain, and best practice entails early surgical management. Ultrasound is the standard modality used to confirm diagnosis. Our objective was to perform a systematic review and meta-analysis to determine the diagnostic accuracy of emergency physician-performed point-of-care ultrasound for the diagnosis of acute cholecystitis when compared with a reference standard of final diagnosis (informed by available surgical pathology, discharge diagnosis, and radiology-performed ultrasound). We completed a systematic review and meta-analysis, registered in PROSPERO, in adherence to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched 7 databases as well as gray literature in the form of select conference abstracts from inception to February 8, 2023. Two independent reviewers completed study selection, data extraction, and risk of bias (QUADAS-2) assessment. Disagreements were resolved by consensus with a third reviewer. Data were extracted from eligible studies to create 2 × 2 tables for diagnostic accuracy meta-analysis. Hierarchical Summary Receiver Operating Characteristic models were constructed. Of 1855 titles/abstracts, 40 were selected for full-text review. Ten studies (n=2356) were included. Emergency physician-performed point-of-care ultrasound with final diagnosis as the reference standard (7 studies, n=1,772) had a pooled sensitivity of 70.9% (95% confidence interval [CI] 62.3 to 78.2), specificity of 94.4% (95% CI 88.2 to 97.5), positive likelihood ratio of 12.7 (5.8 to 27.5), and negative likelihood ratio of 0.31 (0.23 to 0.41) for the diagnosis of acute cholecystitis. Emergency physician-performed point-of-care ultrasound has high specificity and moderate sensitivity for the diagnosis of acute cholecystitis in patients with clinical suspicion. This review supports the use of emergency physician-performed point-of-care ultrasound to rule in a diagnosis of acute cholecystitis in the emergency department, which may help expedite definitive management.

Inhibitory tendon-evoked reflex is attenuated in the torque-depressed isometric steady-state following active shortening.

Residual torque depression (rTD) is the reduction in steady-state isometric torque following an active shortening contraction when compared with an isometric contraction at the same muscle length and activation level. We have shown that spinal excitability increases in the rTD state, yet the mechanisms remains unknown. Percutaneous electrical tendon stimulation was used to induce tendon-evoked inhibitory reflexes. We demonstrated that in the rTD state, reduced torque contributes to a reduction in inhibitory afferent feedback, which indicates that the history-dependent properties of muscle can alter spinal excitability and the voluntary control of submaximal contractions through changes in peripheral afferent feedback. Novelty Residual force depression is a basic property of skeletal muscle, which can influence spinal and supraspinal excitability via inhibitory reflex activity. Residual force depression alters the voluntary control of force.