'Walking epidural': comparison of the analgesic efficacy of levobupivacaine 0.0625% + fentanyl 2mcg/mL versus ropivacaine 0.075% + fentanyl 2mcg/mL.

INTRODUCTION: Epidural infusion with low local anesthetic concentrations with opiates decrease the severity of the motor blockade associated. The present study aims to compare the analgesic efficacy and the motor blockade between two local anesthetic epidural infusions: levobupivacaine 0.0625% + fentanyl 2mcg/mL versus ropivacaine 0.075% + fentanyl 2mcg/mL. MATERIALS AND METHODS: In a single-blind prospective randomized study, 60 laboring parturient had continuous epidural analgesia as follows: 30 of them received levobupivacaine 0.0625% + fentanyl 2mcg/mL and 30 of them received ropivacaine 0.075% + fentanyl 2mcg/mL and rates of infusion were adjusted to the height. Analgesic, motor blockade and satisfaction records were collected as well as maternal and neonate adverse events. RESULTS: After 2 h of the catheter placement, patients who received levobupivacaine showed a mean VAS of 3.2 [1.8-4.6] versus 1.8 [1.2-2.5] (p = 0.05) in patients who received ropivacaine. In addition, patients who received levobupivacaine showed a punctuation in Bromage scale of 0.0 [0.0-1.0] versus 0.0 [0.0-0.0] (p = 0.04) in patients who received ropivacaine. Finally, the parturient who received levobupivacaine scored a mean satisfaction index of 8.1 [7.3-8.9] versus 9.3 [8.7-9.8] (p = 0.02) in those who received ropivacaine. We did not register maternal nor neonate adverse events. CONCLUSION: Both infusions (levobupivacaine 0.0625% + fentanyl 2mcg/mL and ropivacaine 0.075% + fentanyl 2mcg/mL) are effective for labor analgesia. However, ropivacaine would present a better pharmacodynamic profile with less motor blockade and decreased need for analgesic rescue hence improving patient's satisfaction.

Individualizing mechanical ventilation: titration of driving pressure to pulmonary elastance through Young's modulus in an acute respiratory distress syndrome animal model.

BACKGROUND: Mechanical ventilation increases the risk of lung injury (VILI). Some authors propose that the way to reduce VILI is to find the threshold of driving pressure below which VILI is minimized. In this study, we propose a method to titrate the driving pressure to pulmonary elastance in an acute respiratory distress syndrome model using Young's modulus and its consequences on ventilatory-induced lung injury. MATERIAL AND METHODS: 20 Wistar Han male rats were used. After generating an acute respiratory distress syndrome, two groups were studied: (a) standard protective mechanical ventilation: 10 rats received 150 min of mechanical ventilation with driving pressure = 14 cm H2O, tidal volume < 6 mL/kg) and (b) individualized mechanical ventilation: 10 rats received 150 min of mechanical ventilation with an individualized driving pressure according to their Young's modulus. In both groups, an individualized PEEP was programmed in the same manner. We analyzed the concentration of IL-6, TNF-α, and IL-1ß in BAL and the acute lung injury score in lung tissue postmortem. RESULTS: Global driving pressure was different between the groups (14 vs 11 cm H2O, p = 0.03). The individualized mechanical ventilation group had lower concentrations in bronchoalveolar lavage of IL-6 (270 pg/mL vs 155 pg/mL, p = 0.02), TNF-α (292 pg/mL vs 139 pg/mL, p < 0.01) and IL-1ß (563 pg/mL vs 131 pg/mL, p = 0.05). They presented lower proportion of lymphocytes (96% vs 79%, p = 0.05) as well as lower lung injury score (6.0 points vs 2.0 points, p = 0.02). CONCLUSION: In our model, individualization of DP to pulmonary elastance through Young's modulus decreases lung inflammation and structural lung injury without a significant impact on oxygenation.

Prevalence and clinical consequences of atelectasis in SARS-CoV-2 pneumonia: a computed tomography retrospective cohort study.

BACKGROUND: The aim of the study is to estimate the prevalence of atelectasis assessed with computer tomography (CT) in SARS-CoV-2 pneumonia and the relationship between the amount of atelectasis with oxygenation impairment, Intensive Care Unit admission rate and the length of in-hospital stay. PATIENTS AND METHODS: Two-hundred thirty-seven patients admitted to the hospital with SARS-CoV-2 pneumonia diagnosed by clinical, radiology and molecular tests in the nasopharyngeal swab who underwent a chest computed tomography because of a respiratory worsening from Apr 1 to Apr 30, 2020 were included in the study. Patients were divided into three groups depending on the presence and amount of atelectasis at the computed tomography: no atelectasis, small atelectasis (< 5% of the estimated lung volume) or large atelectasis (> 5% of the estimated lung volume). In all patients, clinical severity, oxygen-therapy need, Intensive Care Unit admission rate, the length of in-hospital stay and in-hospital mortality data were collected. RESULTS: Thirty patients (19%) showed small atelectasis while eight patients (5%) showed large atelectasis. One hundred and seventeen patients (76%) did not show atelectasis. Patients with large atelectasis compared to patients with small atelectasis had lower SatO2/FiO2 (182 vs 411 respectively, p = 0.01), needed more days of oxygen therapy (20 vs 5 days respectively, p = 0,02), more frequently Intensive Care Unit admission (75% vs 7% respectively, p < 0.01) and a longer period of hospitalization (40 vs 14 days respectively p < 0.01). CONCLUSION: In patients with SARS-CoV-2 pneumonia, atelectasis might appear in up to 24% of patients and the presence of larger amount of atelectasis is associated with worse oxygenation and clinical outcome.