Both doses of remifentanil effectively attenuated haemodynamic responses to tracheal intubation with transient neonatal respiratory depression in pre-eclamptic patients undergoing Caesarean delivery under general anaesthesia. The 1.0 µg kg⁻¹ dose was associated with hypotension in three of 24 subjects.

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BackgroundThe aims of this study were to compare the efficacy of sevoflurane inhalation alone, intravenous remifentanil alone, and the combination of sevoflurane inhalation and remifentanil as pretreatment for the prevention of rocuronium-induced withdrawal movement in pediatric patients.MethodsIn this prospective, randomized study, 90 American Society of Anesthesiologists physical status I or II pediatric patients aged 3 to 10 years were randomly allocated to one of three treatment groups: The Group S comprising the patients receiving sevoflurane inhalation, the Group R comprising those doing intravenous remifentanil 0.5 µg/kg and the Group C comprising those doing sevoflurane inhalation+intravenous remifentanil 0.5 µg/kg. The response of the patients was graded based on a 4-point scale.ResultsThe overall incidence of withdrawal movement on rocuronium injection was 54% (16/30) in the Group S, 57% (17/30) in the Group R and 17% (5/30) in the Group C. There was no significant difference in the incidence of withdrawal movements on rocuronium injection between the Group S and Group R. In addition, the incidence of withdrawal movements and generalized movement on rocuronium injection was significantly lower in the Group C as compared with the Group S and R (P < 0.05).ConclusionsOur results indicate not only that there was no significant difference in the degree of the effect in lowering the incidence of withdrawal movements on rocuronium injection between sevoflurane inhalation and intravenous remifentanil but also that it was significantly higher when combined with intravenous remifentanil as compared with the single use of sevoflurane inhalation or intravenous remifentanil.

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BackgroundA low fraction of inspired oxygen (FiO2) increases venous deoxygenated hemoglobin concentrations, making the color of the blood darker. The present study was aimed to determine the effects of FiO2 on the ability to discriminate venous from arterial blood.MethodsOne-hundred and sixty surgical patients undergoing percutaneous central venous access of the internal jugular vein were randomly assigned to receive an FiO2 of 0.2, 0.4, 0.6, or 1.0 (n = 40 each) for at least 20 min prior to central line placement under general anesthesia. Vascular access was achieved with a 22-gauge needle; 2 ml of blood was withdrawn and shown to three physicians including the operator. Each of them was asked to identify the blood as 'arterial', 'venous' or 'not sure'. Simultaneous blood gas analysis of the samples was performed on blood taken from the puncture site and the artery after visual comparison to confirm blood's origin and hemodynamic measurements.ResultsLowering FiO2 progressively increased venous deoxygenated hemoglobin concentrations (2.24 ± 1.12, 3.30 ± 1.08, 3.66 ± 1.15, and 3.71 ± 1.33 g/dl) in groups having an FiO2 of 1.0, 0.6, 0.4 and 0.2, respectively (P < 0.001), thereby facilitating the 'venous' blood identification (P < 0.001). Neither heart rate nor mean arterial pressure differed among the groups. None developed hypoxemia (percutaneous hemoglobin oxygen saturation < 90%) in any group during the study period.ConclusionsA low FiO2 increases venous deoxygenated hemoglobin levels, thereby facilitating the recognition by clinicians of its venous origin in percutaneous central venous catheterization under general anesthesia.