Impact of emergency physician performed ultrasound in the evaluation of adult patients with acute abdominal pain: a prospective randomized bicentric trial.

BACKGROUND: Abdominal pain is common in patients visiting the emergency department (ED). The aim of this study was to assess the diagnostic contribution of point-of-care ultrasound (POCUS) in patients presenting to the ED with acute abdominal pain. METHODS: We designed an interventional randomized, controlled, open label, parallel-group, trial in two French EDs. We included adult patients presenting to the ED with acute abdominal pain. Exclusion criteria were a documented end-of-life, an immediate need of life-support therapy and pregnant or breast-feeding women. Patients were randomized in the experimental group (i.e., workup including POCUS) or control group (usual care). The primary objective of the study was to assess the added value of POCUS on diagnostic pathway in the ED, according to the diagnostic established a posteriori by an adjudication committee. The primary endpoint was the proportion of exact preliminary diagnosis between the 2 groups. The preliminary diagnosis made after clinical examination and biological results with POCUS (intervention arm) or without POCUS (usual care) was considered exact if it was similar to the adjudication committee diagnosis. RESULTS: Between June 2021 11th and June 2022 23th, 256 patients were randomized, but five were not included in the primary analysis, leaving 125 patients in the POCUS group and 126 patients in the usual care group (130 women and 121 men, median [Q1-Q3] age: 42 [30;57]). There was no difference for exact diagnosis between the two groups (POCUS 70/125, 56% versus control 78/126 (62%), RD 1.23 [95% CI 0.74-2.04]). There was no difference in the accuracy for the diagnosis of non-specific abdominal pain nor number of biological or radiological exams. Diagnostic delays and length of stay in the ED were also similar. CONCLUSIONS: In this trial, systematic POCUS did not improve the rate of diagnostic accuracy in unselected patients presenting to the ED with acute abdominal pain. However, as it was a safe procedure, further research should focus on patients with suspected etiologies where POCUS is particularly useful. TRIAL REGISTRATION:  This trial was registered on ClinicalTrials.gov on 2022/07/20 ( https://clinicaltrials.gov/study/NCT04912206?id=NCT04912206&rank=1 ) (NCT04912206).

Accuracy of pulse CO-oximetry to evaluate blood carboxyhemoglobin level: a systematic review and meta-analysis of diagnostic test accuracy studies.

Carbon monoxide (CO) poisoning is one of the most common causes of poisoning death and its diagnosis requires an elevated carboxyhemoglobin (COHb) level. Noninvasive CO saturation by pulse oximetry (SpCO) has been available since 2005 and has the advantage of being portable and easy to use, but its accuracy in determining blood COHb level is controversial. To evaluate the accuracy of SpCO (index test) to estimate COHb (reference test). Systematic review and meta-analysis of diagnostic test accuracy (DTA) studies. Four electronic databases were searched (Medline, Embase, Cochrane Central Register of Controlled Trials, and OpenGrey) on 2 August 2022. All studies of all designs published since the 2000s evaluating the accuracy and reliability of SpCO measurement compared to blood COHb levels in human volunteers or ill patients, including children, were included. The primary outcome was to assess the diagnostic accuracy of SpCO for estimating COHb by blood sampling by modeling receiver operating characteristic (ROC) curves and calculating sensitivity and specificity (primary measures). The secondary measures were to calculate the limits of agreement (LOA) and the mean bias. This systematic review was conducted according to the Preferred Reporting Items for a Systematic Review and Meta-analysis-DTA 2018 guidelines and has been registered on International Prospective Register of Systematic Reviews (PROSPERO, CRD42020177940). The risk of bias was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Twenty-one studies were eligible for the systematic review; 11 could be included for the quantitative analysis of the primary measures and 18 for the secondary measures. No publication bias was found. The area under the summary ROC curve was equal to 86%. The mean sensitivity and specificity were 0.77, 95% confidence interval (CI, 0.66-0.85) and 0.83, 95% CI (0.74-0.89), respectively (2089 subjects and 3381 observations). The mean bias was 0.75% and the LOA was -7.08% to 8.57%, 95% CI (-8.89 to 10.38) (2794 subjects and 4646 observations). Noninvasive measurement of COHb (SpCO) using current pulse CO oximeters do not seem to be highly accurate to estimate blood COHb (moderate sensitivity and specificity, large LOA). They should probably not be used to confirm (rule-in) or exclude (rule-out) CO poisoning with certainty.