Ventilatory associated barotrauma in COVID-19 patients: A multicenter observational case control study (COVI-MIX-study)

Background: The risk of barotrauma associated with different types of ventilatory support is unclear in COVID-19 patients. The primary aim of this study was to evaluate the effect of the different respiratory support strategies on barotrauma occurrence; we also sought to determine the frequency of barotrauma and the clinical characteristics of the patients who experienced this complication. Methods: This multicentre retrospective case-control study from 1 March 2020 to 28 February 2021 included COVID-19 patients who experienced barotrauma during hospital stay. They were matched with controls in a 1:1 ratio for the same admission period in the same ward of treatment. Univariable and multivariable logistic regression (OR) were performed to explore which factors were associated with barotrauma and in-hospital death. Results: We included 200 cases and 200 controls. Invasive mechanical ventilation was used in 39.3% of patients in the barotrauma group, and in 20.1% of controls (p<0.001). Receiving non-invasive ventilation (C-PAP/PSV) instead of conventional oxygen therapy (COT) increased the risk of barotrauma (OR 5.04, 95% CI 2.30 - 11.08, p<0.001), similarly for invasive mechanical ventilation (OR 6.24, 95% CI 2.86-13.60, p<0.001). High Flow Nasal Oxygen (HFNO), compared with COT, did not significantly increase the risk of barotrauma. Barotrauma frequency occurred in 1.00% [95% CI 0.88-1.16] of patients; these were older (p=0.022) and more frequently immunosuppressed (p=0.013). Barotrauma was shown to be an independent risk for death (OR 5.32, 95% CI 2.82-10.03, p<0.001). Conclusions: C-PAP/PSV compared with COT or HFNO increased the risk of barotrauma; otherwise HFNO did not. Barotrauma was recorded in 1.00% of patients, affecting mainly patients with more severe COVID-19 disease. Barotrauma was independently associated with mortality. Trial registration: this case-control study was prospectively registered in clinicaltrial.gov as NCT04897152 (on 21 May 2021)

Cardiac output measurement in liver transplantation patients using pulmonary and transpulmonary thermodilution: a comparative study

During liver transplantation surgery, the pulmonary artery catheter—despite its invasiveness—remains the gold standard for measuring cardiac output. However, the new EV1000 transpulmonary thermodilution calibration technique was recently introduced into the market by Edwards LifeSciences. We designed a single-center prospective observational study to determine if these two techniques for measuring cardiac output are interchangeable in this group of patients. Patients were monitored with both pulmonary artery catheter and the EV1000 system. Simultaneous intermittent cardiac output measurements were collected at predefined steps: after induction of anesthesia (T1), during the anhepatic phase (T2), after liver reperfusion (T3), and at the end of the surgery (T4). The 4-quadrant and polar plot techniques were used to assess trending ability between the two methods. We enrolled 49 patients who underwent orthotopic liver transplantation surgery. We analyzed a total of 588 paired measurements. The mean bias between pulmonary artery catheter and the EV1000 system was 0.35&nbsp;L/min with 95% limits of agreement of − 2.30 to 3.01&nbsp;L/min, and an overall percentage error of 35%. The concordance rate between the two techniques in 4-quadrant plot analysis was 65% overall. The concordance rate of the polar plot showed an overall value of 83% for all pairs. In the present study, in liver transplantation patients we found that intermittent cardiac output monitoring with EV1000 system showed a percentage error compared with pulmonary artery catheter in the acceptable threshold of 45%. On the others hand, our results showed a questionable trending ability between the two techniques

Airway management in anesthesia for thoracic surgery: A “real life” observational study

Background: One-lung ventilation (OLV) in thoracic anesthesia is required to provide good surgical exposure. OLV is commonly achieved through a double lumen tube (DLT) or a bronchial blocker (BB). Malposition is a relevant issue related to these devices use. No prospective studies with adequately large sample size have been performed to evaluate the malposition rate of DLTs and BBs. Methods: A total of 2,127 patients requiring OLV during thoracic surgery were enrolled. The aim of this multicenter prospective observational study performed across 26 academic and community hospitals is to evaluate intraoperative malposition rate of DLTs and BBs. We also aim to assess: which device is the most used to achieve OLV, the frequency of bronchoscope (BRO) use, the incidence rate of desaturation during OLV and the role of other factors that can correlate to this event, and incidence of difficult airway. Results: Malposition rate for DLTs was 14%, for BBs 33%. DLTs were used in 95% of patients and BBs in 5%. Mean positioning time was shorter for DLT than BB (156±230 vs. 321±290 s). BRO was used in 54% of patients to check the correct positioning of the DLT. Desaturation occurred in 20% of all cases during OLV achieved through a DLT. Predicting factors of desaturation were dislocation (OR 2.03) and big size of DLT (OR 1.15). BRO use (OR 0.69) and left surgical side (OR 0.41) proved to be protective factors. Difficult airway prevalence was 16%; 10.8% predicted and 5.2% unpredicted. Conclusions: DLT has a low malpositioning rate and is the preferred device to achieve OLV. BRO use recorded was unexpectedly low. The possibility of encountering a difficult airway is frequent, with an overall prevalence of 16%. Risk factors of desaturation are malposition and increased size of DLT. Left procedures and BRO use could lead to fewer episodes of desaturation