Prehospital ultrasound scanning for abdominal free fluid detection in trauma patients: a systematic review and meta-analysis.

INTRODUCTION: Focused assessment with sonography for trauma helps detect abdominal free fluid. Prehospital ultrasound scanning is also important because the early diagnosis of hemoperitoneum may reduce the time to definitive treatment in the hospital. This study investigated whether prehospital ultrasound scanning can help detect abdominal free fluid. MATERIALS AND METHODS: In this systematic review, relevant databases were searched for studies investigating prehospital ultrasound examinations for abdominal free fluid in trauma patients. The prehospital ultrasound results were compared with computed tomography, surgery, or hospital ultrasound examination data. The pooled sensitivity and specificity values were analyzed using forest plots. The overall predictive power was calculated by the summary receiver operating characteristic curve. The quality of the included studies was assessed using the quality assessment of diagnostic accuracy studies tool. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was performed to assess the certainty of evidence. RESULT: This meta-analysis comprised six studies that included 1356 patients. The pooled sensitivity and specificity values were 0.596 (95% confidence interval [CI] = 0.345-0.822) and 0.970 (95% CI = 0.953-0.983), respectively. The pooled area under the summary receiver operating characteristic curve was 0.998. The quality assessment tool showed favorable results. In the GRADE analysis, the quality of evidence was very low for sensitivity and high for specificity when prehospital ultrasound was used for hemoperitoneum diagnosis. CONCLUSION: The specificity of abdominal free fluid detection using prehospital ultrasound examinations in trauma patients was very high.

The effect of the head-up position on cardiopulmonary resuscitation: a systematic review and meta-analysis.

OBJECTIVE: Experimental studies of head-up positioning (HUP) during cardiopulmonary resuscitation (CPR) have had some degree of conflicting published results. The current study aim was to analyze and reconcile those discrepancies in order to better clarify the effects of HUP CPR compared to conventional supine (SUP) CPR. METHODS: Three databases (PubMed, EMBASE and Cochrane Library) were searched comprehensively (from each respective database's inception to May 2021) for articles addressing HUP CPR. The primary outcome to be observed was cerebral perfusion pressure (CerPP), and secondary outcomes were mean intracranial pressure (ICP), mean arterial pressure (MAP), coronary perfusion pressure (CoPP) and frequencies of return of spontaneous circulation (ROSC). RESULTS: Seven key studies involving 131 animals were included for analysis. Compared to SUP CPR, CerPP (MD 10.37; 95% CI 7.11-13.64; p < 0.01; I2 = 58%) and CoPP (MD 7.56; 95% CI 1.84-13.27, p = 0.01; I2 = 75%) increased significantly with HUP CPR, while ICP (MD - 13.66; 95% CI - 18.6 to -8.71; p < 0.01; I2 = 96%) decreased significantly. Combining all study methodologies, there were no significant differences detected in MAP (MD - 1.63; 95% CI - 10.77-7.52; p = 0.73; I2 = 93%) or frequency of ROSC (RR 0.9; 95% CI 0.31-2.60; p = 0.84; I2 = 65%). However, in contrast to worse outcomes in studies using immediate elevation of the head in a reverse Trendelenburg position, study outcomes were significantly improved when HUP (head and chest only) was introduced in a steady, graduated manner following a brief period of basic CPR augmented by active compression-decompression (ACD) and impedance threshold (ITD) devices. CONCLUSION: In experimental models, gradually elevating the head and chest following a brief interval of circulatory priming with ACD and ITD devices can enhance CoPP, lower ICP and improve CerPP significantly while maintaining MAP. This effect is immediate, remains sustained and is associated with improved outcomes.