A machine learning COVID-19 mass screening based on symptoms and a simple olfactory test.

The early detection of symptoms and rapid testing are the basis of an efficient screening strategy to control COVID-19 transmission. The olfactory dysfunction is one of the most prevalent symptom and in many cases is the first symptom. This study aims to develop a machine learning COVID-19 predictive tool based on symptoms and a simple olfactory test, which consists of identifying the smell of an aromatized hydroalcoholic gel. A multi-centre population-based prospective study was carried out in the city of Reus (Catalonia, Spain). The study included consecutive patients undergoing a reverse transcriptase polymerase chain reaction test for presenting symptoms suggestive of COVID-19 or for being close contacts of a confirmed COVID-19 case. A total of 519 patients were included, 386 (74.4%) had at least one symptom and 133 (25.6%) were asymptomatic. A classification tree model including sex, age, relevant symptoms and the olfactory test results obtained a sensitivity of 0.97 (95% CI 0.91-0.99), a specificity of 0.39 (95% CI 0.34-0.44) and an AUC of 0.87 (95% CI 0.83-0.92). This shows that this machine learning predictive model is a promising mass screening for COVID-19.

Clinical outcomes and safety of passive leg raising in out-of-hospital cardiac arrest: a randomized controlled trial.

BACKGROUND: There are data suggesting that passive leg raising (PLR) improves hemodynamics during cardiopulmonary resuscitation (CPR). This trial aimed to determine the effectiveness and safety of PLR during CPR in out-of-hospital cardiac arrest (OHCA). METHODS: We conducted a randomized controlled trial with blinded assessment of the outcomes that assigned adults OHCA to be treated with PLR or in the flat position. The trial was conducted in the Camp de Tarragona region. The main end point was survival to hospital discharge with good neurological outcome defined as cerebral performance category (CPC 1-2). To study possible adverse effects, we assessed the presence of pulmonary complications on the first chest X-rays, brain edema on the computerized tomography (CT) in survivors and brain and lungs weights from autopsies in non-survivors. RESULTS: In total, 588 randomized cases were included, 301 were treated with PLR and 287 were controls. Overall, 67.8% were men and the median age was 72 (IQR 60-82) years. At hospital discharge, 3.3% in the PLR group and 3.5% in the control group were alive with CPC 1-2 (OR 0.9; 95% CI 0.4-2.3, p = 0.91). No significant differences in survival at hospital admission were found in all patients (OR 1.0; 95% CI 0.7-1.6, p = 0.95) and among patients with an initial shockable rhythm (OR 1.7; 95% CI 0.8-3.4, p = 0.15). There were no differences in pulmonary complication rates in chest X-rays [7 (25.9%) vs 5 (17.9%), p = 0.47] and brain edema on CT [5 (29.4%) vs 10 (32.6%), p = 0.84]. There were no differences in lung weight [1223 mg (IQR 909-1500) vs 1239 mg (IQR 900-1507), p = 0.82] or brain weight [1352 mg (IQR 1227-1457) vs 1380 mg (IQR 1255-1470), p = 0.43] among the 106 autopsies performed. CONCLUSION: In this trial, PLR during CPR did not improve survival to hospital discharge with CPC 1-2. No evidence of adverse effects has been found. Clinical trial registration ClinicalTrials.gov: NCT01952197, registration date: September 27, 2013, https://clinicaltrials.gov/ct2/show/NCT01952197 .