Almitrine fails to improve oxygenation during one-lung ventilation with sevoflurane anesthesia.

OBJECTIVE: Almitrine enhances hypoxic pulmonary vasoconstriction (HPV) and can improve hypoxemia related to one-lung ventilation (OLV). Studies using almitrine have been conducted without inhaled anesthetics because they could inhibit HPV, counteracting the effect of almitrine. This hypothesis, however, has not been confirmed. This study's aim was to evaluate whether almitrine could improve oxygenation when administered during OLV with sevoflurane anesthesia. DESIGN: A prospective, randomized, double-blind, placebo-controlled trial. SETTING: A tertiary care, university teaching hospital. PARTICIPANTS: Thirty adult patients undergoing open-chest thoracic surgery. INTERVENTIONS: Patients were assigned randomly to receive almitrine or placebo during OLV. Respiratory and hemodynamic variables were recorded continuously. Anesthesia was maintained with sevoflurane and remifentanil. Intraoperative techniques and medical teams were the same all over the study. MEASUREMENTS AND MAIN RESULTS: Respiratory and hemodynamic variables were measured during two-lung ventilation and during open-chest OLV. Two-way repeated-measures analysis of variance was used to compare the effects of almitrine and placebo. During OLV, PaO2 and shunt fraction worsened in all patients without significant differences between groups. At 30-minutes of OLV, PaO2 was 184±67 mmHg in the almitrine group and 145±56 mmHg in the placebo group, while shunt fraction were 31%±6% and 36%±13%, respectively. Mean pulmonary artery pressure was higher in the almitrine group (31±5 v 24±5 mmHg, p<0.001). CONCLUSIONS: During anesthesia with sevoflurane for open-chest OLV, almitrine failed to improve oxygenation and increased pulmonary artery pressure. The combination of sevoflurane and almitrine should, therefore, be avoided.

Moderate sedation with dexmedetomidine-remifentanil is safer than deep sedation with propofol-remifentanil for endobronchial ultrasound while providing comparable quality: a randomized double-blind trial.

OBJECTIVE: We compared dexmedetomidine-remifentanil vs. propofol-remifentanil in terms of safety and quality during sedation for Endobronchial ultrasonography (EBUS). METHODS: A randomized, double-blind trial. Outpatients undergoing EBUS randomly received 1 µg/kg/hour dexmedetomidine or a target concentration of 2.5 µg/mL propofol, both combined with remifentanil initially targeted at 1.5 ng/mL and subsequently titrated. Additional sedatives were restricted. The primary outcome was the need for airway rescue interventions to treat oxygen desaturation. RESULTS: Twenty-eight patients received dexmedetomidine-remifentanil and 27 received propofol-remifentanil. Airway rescue interventions were fewer in the dexmedetomidine group vs. the propofol one (23 vs. 76% patients, relative risk 3.21 (95% CI 1.55-6.64, P < 0.002)). Desaturation in the dexmedetomidine group was always resolved by increasing nasal oxygen flow, whereas additional interventions were needed in 60% of patients receiving propofol. Hypotension was more frequent in the propofol group, while hypertension, bradycardia and coughing were similar in both. Bronchoscopists' and patients' satisfaction were similar, although in the dexmedetomidine group two patients needed additional sedatives and two patients would not repeat the sedation technique. CONCLUSION: Moderate sedation with dexmedetomidine-remifentanil for EBUS is safer than deep sedation with propofol-remifentanil but it would occasionally need additional sedatives to ensure patient satisfaction.