BackgroundNot only arterial hypoxemia but acute lung injury also has become the major concerns of one-lung ventilation (OLV). The use of pressure-controlled ventilation (PCV) for OLV offers the potential advantages of lower airway pressure and intrapulmonary shunt, which result in a reduced risk of barotrauma and improved oxygenation, respectively.MethodsWe searched Medline, Embase, the Cochrane central register of controlled trials and KoreaMedto find publications comparing the effects of PCV with those of volume-controlled ventilation (VCV) during intraoperative OLV in adults. A meta-analysis of randomized controlled trials was performed using the Cochrane Review Methods.ResultsSix studies (259 participants) were included. The PaO2/FiO2 ratio in PCV was higher than in VCV [weighted mean difference (WMD) = 11.04 mmHg, 95 % confidence interval (CI) = 0.30 to 21.77, P = 0.04, I2 = 3 %] and peak inspiratory pressure was significantly lower in PCV (WMD = −4.91 cm H2O, 95 % CI = −7.30 to –2.53, P < 0.0001, I 2 = 91 %). No differences in PaCO2, tidal volume, heart rate and blood pressure were observed. There were also no differences incompliance, plateau and mean airway pressure.ConclusionsOur meta-analysis provided the evidence of improved oxygenation in PCV. However, it is difficult to draw any definitive conclusions due to the fact that the duration of ventilation in the studies reviewed was insufficient to reveal clinically relevant benefits or disadvantages of PCV. Significantly lower peak inspiratory pressure is the advantage of PCV.Electronic supplementary materialThe online version of this article (doi:10.1186/s12871-016-0238-6) contains supplementary material, which is available to authorized users.

Background The induction of general anesthesia may cause hemodynamic instability. Remifentanil is often administered to suppress the hemodynamic response. We aimed to evaluate the effect of remifentanil infusion on the hemodynamic response to induction of anesthesia in hypertensive and normotensive patients. Methods Patients were divided into two groups: Group H (n = 102) were hypertensive patients and Group C (n = 107) were normotensive patients. During induction, all patients received 1 µg/kg of remifentanil as a loading dose over 2 minutes, followed by a continuous infusion at 0.05 µg/kg/minute. We analyzed the systolic, diastolic, and mean pressures and heart rate pre-induction, pre-intubation, immediately post-intubation, and at 2, 4, 6, 8, and 10 minutes after intubation. Results The systolic, diastolic, and mean pressures before induction were significantly higher in group H compared with group C, but there was no significant difference between the two groups immediately after intubation. Blood pressures immediately after intubation were similar to the pre-induction blood pressure. There was no significant difference in heart rate between the two groups at any time point. Conclusions Remifentanil infusion effectively attenuates the hemodynamic response to induction of general anesthesia in hypertensive and normotensive patients.

BackgroundMore laparoscopic low anterior resections (LAR) are being performed in recent years. There has been controversy around the hemodynamic changes affected by the Trendelenburg position and pneumoperitoneum during LAR. The goal of this study was to analyze the effect of nitroglycerin (NTG) on hemodynamic changes during LAR.MethodsForty ASA physical status I-II patients undergoing LAR were randomized into two groups: the NTG infused group (N group, n = 20) and the control group (C group, n = 20). Anesthesia was maintained with sevoflurane at 1-3 vol%, air/oxygen (50%/50%) and continuous infusion with remifentanil. The N group patients were given 0.5 µg/kg/min of NTG during anesthesia. Mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), cardiac index (CI), stroke volume (SV) and systemic vascular resistance (SVR) were assessed 10 min after induction (T1), 5 min after pneumoperitoneum in the supine position (T2), 10 min after pneumoperitoneum in the Trendelenburg position (T3), 30 min after pneumoperitoneum in the Trendelenburg position (T4), 1 hr after pneumoperitoneum in the Trendelenburg position (T5) in addition to 5 (T6), 10 (T7) and 30 min (T8) after removal of the pneumoperitoneum in the supine position.ResultsThe increases of MAP were milder in the N group (22.6-7.3%) than the C group (32.3-17.7%) during pneumoperitoneum and while in the Trendelenburg position. The significant decreases of HR were maintained in the C group, but the changes in HR were not significant in N group during the operation. The increases in CVP were less in N group than C group. The increases of SVR were milder in N group (19.4-1.4%) than C group (41.7-16.6%) during pneumoperitoneum in the Trendelenburg position.ConclusionsIntraoperative NTG infusions were effective to some degree in reducing the hemodynamic changes during pneumoperitoneum with Trendelenburg positioning for LAR.