Relationship between Stroke Volume Variation and Blood Transfusion during Liver Transplantation.

BACKGROUND: Intraoperative blood transfusion increases the risk for perioperative mortality and morbidity in liver transplant recipients. A high stroke volume variation (SVV) method has been proposed to reduce blood loss during living donor hepatectomy. Herein, we investigated whether maintaining high SVV could reduce the need for blood transfusion and also evaluated the effect of the high SVV method on postoperative outcomes in liver transplant recipients. METHODS: We retrospectively analyzed 332 patients who underwent liver transplantation, divided into control (maintaining <10% of SVV during surgery) and high SVV (maintaining 10-20% of SVV during surgery) groups. We evaluated the blood transfusion requirement and hemodynamic parameters, including SVV, as well as postoperative outcomes, such as incidences of acute kidney injury, durations of postoperative intensive care unit and hospital stay, and rates of 1-year mortality. RESULTS: Mean SVV values were 7.0% ± 1.3% in the control group (n = 288) and 11.2% ± 1.8% in the high SVV group (n = 44). The median numbers of transfused packed red blood cells and fresh frozen plasmas in the high SVV group were significantly lower than those in control group (0 vs. 2 units, P = 0.003; and 0 vs. 3 units, P = 0.033, respectively). No significant between-group differences were observed for postoperative outcomes. CONCLUSIONS: Maintaining high SVV can reduce the blood transfusion requirement during liver transplantation without worsening postoperative outcomes. These findings provide insights into improving perioperative management in liver transplant recipients.

A proposal of a simple epidural simulator for training novice anesthesiologists.

PURPOSE: Confirming the epidural space during epidural anesthesia relies mainly on feel and experience, which are difficult techniques for a trainee to learn. We designed an epidural simulator for trainees to experience loss of resistance (LOR) and various degrees of pressure resistance. METHODS: The simulator consists of a Perifix(®) LOR syringe and 1-, 5-, 10- and 50-mL syringes assembled by three-way stopcocks. A total of 89 anesthesiologists evaluated the simulator, given the choice of either the intermittent technique with air or continuous technique with saline. Sudden LOR and applicability of the simulator for training purposes were assessed using the numerical rating score (NRS). Pressure resistance at each lumbar structure was evaluated by the anesthesiologists using the intermittent technique with air. RESULTS: Seventy-four anesthesiologists used the intermittent technique with air and 15 used the continuous technique with saline. The NRSs for sudden LOR and the applicability for training purposes were 8 and 9 (median), respectively. The pressure resistance to a 50-mL syringe was regarded as the epidural space (odds ratio 602.3 for 5-mL syringe and 144.4 for 10-mL syringe) by 89 % of anesthesiologists using air for LOR. Resistance to the 10-mL syringe was most frequently considered as muscle, subcutaneous fat, or the interspinous ligament, while resistance to the 1-mL syringe was considered as the ligamentum flavum (odds ratio 2.3 for 5-mL syringe and 18.6 for 10-mL syringe). CONCLUSIONS: Our epidural simulator is a simple, low-cost device that can be easily constructed. It was shown to provide valid haptic feedback as a promising tool for training novice anesthesiologists.

Changes of diaphragmatic excursion and lung compliance during major laparoscopic pelvic surgery: A prospective observational study.

Major laparoscopic pelvic surgery requires steep Trendelenburg position with pneumoperitoneum for a long time. We investigated the effect of Trendelenburg position with pneumoperitoneum on diaphragmatic excursion and lung compliance during major laparoscopic pelvic surgery using M-mode sonography. Twenty patients undergoing elective pelviscopic radical hysterectomy were included in this study. Diaphragmatic excursion was measured at the following time points; after sedation, after intubation, 90 minutes after Trendelenburg position with pneumoperitoneum, and after operation with recovery of muscle relaxation. And lung compliance was measured using anesthetic machine under general anesthesia; after the intubation, 90 minutes after Trendelenburg position with pneumoperitoneum and after operation with recovery of muscle relaxation. In order to detect postoperative pulmonary complication, postoperative chest radiography was checked. Static lung compliance, dynamic lung compliance and diaphragmatic excursion were decreased during operation (P < 0.001, respectively). At the end of the operation with recovery of muscle relaxation, reduced diaphragmatic movement was not recovered as its excursion after sedation (P < 0.001). In conclusion, lung compliance was decreased following transiently decreased diaphragmatic excursion during major laparoscopic pelvic surgery.

Effects of the Trendelenburg Position and Positive End-Expiratory Pressure on the Internal Jugular Vein Cross-Sectional Area in Children With Simple Congenital Heart Defects.

Catheterization of the internal jugular vein (IJV) remains difficult in pediatric populations. Increasing the cross-sectional area (CSA) of the IJV facilitates cannulation and decreases complications. We aimed to evaluate the Trendelenburg position and the levels of positive end-expiratory pressure (PEEP) at which the maximum increase of CSA of the IJV occurred in children undergoing cardiac surgery.In this prospective study, the CSA of the right IJV was assessed using ultrasound in 47 anesthetized pediatric patients with simple congenital heart defects. The baseline CSA was obtained in response to a supine position with no PEEP and compared with 5 different randomly ordered maneuvers, that is, a PEEP of 5 and 10 cm H2O in a supine position and of 0, 5, and 10 cm H2O in a 10° Trendelenburg position. Hemodynamic variables, including blood pressure and heart rate, maximum and minimum diameters, and CSA, were measured.All maneuvers increased the CSA of the right IJV with respect to the control condition. In the supine position, the CSA was increased by 9.4% with a PEEP of 5 and by 19.5% with a PEEP of 10 cm H2O. The Trendelenburg tilt alone increased the CSA by 19.0%, and combining the 10° Trendelenburg with a 10 cm H2O PEEP resulted in the largest IJV CSA increase (33.3%) compared with the supine position with no PEEP. Meanwhile, vital signs remained relatively steady during the experiment.The application of the Trendelenburg position and a 10 cm H2O PEEP thus significantly increases the CSA of the right IJV, perhaps improving the chances of successful cannulation in pediatric patients with simple congenital heart defects.

Blind nasal intubation as an alternative to difficult intubation approaches.

Airway difficulties are a major concern for anesthesiologists. Even though fiberoptic intubation is the generally accepted method for management of difficult airways, it is not without disadvantages-requires patient cooperation, and cannot be performed on soiled airway or upper airways with pre-existing narrowing pathology. Additionally, fiberoptic bronchoscopy is not available at every medical institution. In this case, we encountered difficult airway management in a 71-year-old man with a high Mallampati grade and a thick neck who had undergone urologic surgery. Several attempts, including a bronchoscope-guided intubation, were unsuccessful. Finally, blind nasal intubation was successful while the patient's neck was flexed and the tracheal cartilage was gently pressed down. We suggest that blind nasal intubation is a helpful alternative in difficult airway management and it can be a lifesaving technique in emergencies. Additionally, its simplicity makes it a less expensive option when advanced airway technology (fiberoptic bronchoscopy) is unavailable.