Quick Epidural Top-up with Alkalinized Lidocaine for emergent caesarean delivery (QETAL study): protocol for a randomized, controlled, bicentric trial.

BACKGROUND: General anesthesia in pregnant women can be associated with significant maternal and fetal morbidity. Emergency caesarean section can be performed by converting labor epidural analgesia to surgical anesthesia by injecting high-dose short-acting local anesthetics through the epidural catheter. The effectiveness and the delay to obtain surgical anesthesia depends upon the protocol used. Data indicate that alkalinization of local anesthetics may shorten their onset of action and increase their effectiveness. This study investigates whether alkalinization of adrenalized lidocaine could increase the efficacy and decrease the delay of onset of surgical anesthesia via an indwelling epidural catheter, thus decreasing the necessity to resort to general anesthesia for emergency caesarean deliveries. METHODS: This study will be a bicentric, double-blind, randomized, controlled trial with two parallel groups of 66 women who require emergency caesarian deliveries and who have been receiving epidural labor analgesia. The number of subjects in groups will be unbalanced with a 2:1 ratio of experimental:control. In both groups, all eligible patients will have had an epidural catheter placed for labor analgesia with levobupicaine or ropivacaine. Patient randomization will occur when the decision is made by the surgeon that an emergency caesarean delivery is indicated. Surgical anesthesia will be obtained by injecting 20 mL of 2% lidocaine with epinephrine 1:200,000, or 10 mL 2% lidocaine with epinephrine 1:200,000 plus 2 mL sodium bicarbonate 4.2% (total of 12 mL). The primary outcome will be the rate of conversion to general anesthesia for failure of the epidural to provide adequate analgesia. This study will be powered to detect a 50% reduction in the incidence of general anesthesia, from 80 to 40%, with a confidence ratio of 90%. DISCUSSION: Sodium bicarbonate could be used to avoid general anesthesia for emergency caesarean deliveries by providing reliable and effective surgical anesthesia in women with pre-existing labor epidural catheters is promising. This randomized controlled trial seeks to determine the optimal local anesthetic mixture for converting epidural analgesia to surgical anesthesia for emergency caesarean sections. This may decrease the need for general anesthesia for emergency caesarian section, shorten the time to fetal extraction, and improve safety and patient satisfaction. TRIAL REGISTRATION: ClinicalTrials.gov NCT05313256. Registered on 6 April 2022.

End-Expiratory Occlusion Test Predicts Fluid Responsiveness in Patients With Protective Ventilation in the Operating Room.

BACKGROUND: End-expiratory occlusion test (EEOT) has been proposed to predict fluid responsiveness in mechanically ventilated intensive care unit patients. The utility of this test during low-tidal-volume ventilation remains uncertain. This study aimed to determine whether hemodynamic variations induced by EEOT could predict the effect of volume expansion in patients with protective ventilation in the operating room. METHODS: Forty-one patients undergoing neurosurgery were included. Stroke volume and pulse pressure variations were continuously recorded using pulse contour analysis before and immediately after a 30-second EEOT and after volume expansion (250 mL saline 0.9% given over 10 minutes). Patients with an increase in stroke volume ≥ 10% after volume expansion were defined as responders. RESULTS: Twenty patients were responders to fluid administration. EEOT induced a significant increase in stroke volume, which was correlated with the stroke volume changes induced by volume expansion (r = 0.55, P < .0001). A 5% increase in stroke volume during EEOT discriminated responders to volume expansion with a sensitivity of 100% (95% confidence interval [CI], 83%-100%), a specificity of 81% (95% CI, 58%-95%), a positive predictive value of 84% (95% CI, 64%-96%), and a negative predictive value of 100% (95% CI, 80%-100%). The gray zone ranged from 4% to 8%, including 17% of patients. The best pulse pressure variation threshold was 9%, with a sensitivity of 60% (95% CI, 36%-81%) and specificity of 86% (95% CI, 64%-97%). The area under the receiver operating characteristics curve generated for changes in stroke volume induced by EEOT (0.91, 95% CI, 0.81-1.00) was significantly higher than the one obtained for pulse pressure variations (0.75, 95% CI, 0.60-0.90); P < .05. CONCLUSIONS: Changes in stroke volume index induced by EEOT can predict fluid responsiveness in patients with protective ventilation in the operating room. This test may have potential applications.