The Utility of ABO Testing in Pediatric Patients Undergoing Elective Surgery.

BACKGROUND: Patients for elective operation often undergo routine ABO/Rh type and screening test for potential need of transfusion. Some institutions require double verification of ABO/Rh type. We evaluated the clinical practice pattern of performing ABO/Rh type and screening test in pediatric patients undergoing elective operation. METHODS: Electronic medical records from pediatric patients who underwent elective surgery between June 2006 and June 2010 were retrieved. The frequency of ABO/Rh type and screening test and the incidence of packed red blood cell (pRBC) request and pRBC dispatch from the blood bank among those tested were analyzed by year and the surgical department. RESULTS: Of the 23,631 patients, the incidence of ABO/Rh type and screening was 32.2%, and pRBC was dispatched in 37.9% of these patients. The incidence of ABO/Rh type and screening varied between 1.5% and 97.9% among surgical departments and also within the surgical departments depending on the type of surgery. The incidence of ABO/Rh type and screening showed a decreasing trend over the study period. CONCLUSIONS: There was significant variability among and within the surgical departments in the incidence of ABO/Rh type and screening in children undergoing elective surgery. A tailored approach may be beneficial to the patient in terms of comfort and cost.

Prediction of Bispectral Index during Target-controlled Infusion of Propofol and Remifentanil: A Deep Learning Approach.

BACKGROUND: The discrepancy between predicted effect-site concentration and measured bispectral index is problematic during intravenous anesthesia with target-controlled infusion of propofol and remifentanil. We hypothesized that bispectral index during total intravenous anesthesia would be more accurately predicted by a deep learning approach. METHODS: Long short-term memory and the feed-forward neural network were sequenced to simulate the pharmacokinetic and pharmacodynamic parts of an empirical model, respectively, to predict intraoperative bispectral index during combined use of propofol and remifentanil. Inputs of long short-term memory were infusion histories of propofol and remifentanil, which were retrieved from target-controlled infusion pumps for 1,800 s at 10-s intervals. Inputs of the feed-forward network were the outputs of long short-term memory and demographic data such as age, sex, weight, and height. The final output of the feed-forward network was the bispectral index. The performance of bispectral index prediction was compared between the deep learning model and previously reported response surface model. RESULTS: The model hyperparameters comprised 8 memory cells in the long short-term memory layer and 16 nodes in the hidden layer of the feed-forward network. The model training and testing were performed with separate data sets of 131 and 100 cases. The concordance correlation coefficient (95% CI) were 0.561 (0.560 to 0.562) in the deep learning model, which was significantly larger than that in the response surface model (0.265 [0.263 to 0.266], P < 0.001). CONCLUSIONS: The deep learning model-predicted bispectral index during target-controlled infusion of propofol and remifentanil more accurately compared to the traditional model. The deep learning approach in anesthetic pharmacology seems promising because of its excellent performance and extensibility.

Stroke Volume Variation-Guided Versus Central Venous Pressure-Guided Low Central Venous Pressure With Milrinone During Living Donor Hepatectomy: A Randomized Double-Blinded Clinical Trial.

BACKGROUND: We previously demonstrated the usefulness of milrinone for living donor hepatectomy. However, a less-invasive alternative to central venous catheterization and perioperative contributors to good surgical outcomes remain undetermined. The current study evaluated whether the stroke volume variation (SVV)-guided method can substitute central venous catheterization during milrinone-induced profound vasodilation. METHODS: We randomly assigned 42 living liver donors to receive either SVV guidance or central venous pressure (CVP) guidance to obtain milrinone-induced low CVP. Target SVV of 9% was used as a substitute for CVP of 5 mm Hg. The surgical field grade evaluated by 2 attending surgeons on a 4-point scale was compared between the CVP- and SVV-guided groups (n = 19, total number of scores = 38 per group) as a primary outcome variable. Multivariable analysis was performed to identify independent factors associated with the best surgical field as a post hoc analysis. RESULTS: Surgical field grades, which were either 1 or 2, were not found to be different between the 2 groups via Mann-Whitney U test (P = .358). There was a very weak correlation between SVV and CVP during profound vasodilation such as CVP ≤ 5 mm Hg (R = -0.06; 95% confidence interval, -0.09 to -0.04; P < .001). Additional post hoc analysis suggested that younger age, lower baseline CVP, and longer duration of milrinone infusion might be helpful in providing the best surgical field. CONCLUSIONS: Milrinone-induced vasodilation resulted in favorable surgical environment regardless of guidance methods of low CVP during living donor hepatectomy. However, SVV was not a useful indicator of low CVP because of very weak correlation between SVV and CVP during profound vasodilation. In addition, factors contributing to the best surgical field such as donor age, proactive fasting, and proper dosing of milrinone need to be investigated further, ideally through prospective studies.

Reliability of Point-of-Care Hematocrit Measurement During Liver Transplantation.

BACKGROUND: Although point-of-care (POC) analyzers are commonly used during liver transplantation (LT), the accuracy of hematocrit measurement using a POC analyzer has not been evaluated. In this retrospective observational study, we aimed to evaluate the accuracy of hematocrit measurement using a POC analyzer and identify potential contributors to the measurement error and their influence on mistransfusion during LT. METHODS: We retrospectively collected 6461 pairs of simultaneous intraoperative hematocrit measurements using POC analyzers and laboratory devices during LTs in 901 patients. The agreement of hematocrit measurements was assessed using Bland-Altman analysis for repeated measurements, while the incidence and magnitude of hematocrit measurement error were compared among 16 different laboratory abnormality categories. A generalized estimating equation analysis was performed to identify potential contributors to falsely low-measured POC hematocrit. Additionally, we defined potential "overtransfusion" in the case when POC hematocrit was <20% and laboratory hematocrit was ≥20% and investigated its association with intraoperative transfusion. RESULTS: The POC hematocrit measurements were falsely lower than the laboratory hematocrit measurements in 70.3% (4541/6461) of pairs. The median (interquartile range) of hematocrit measurement error was -1.20 (-2.60 to 0.20). Bland-Altman analysis showed that 24.5% (1583/6461) of the errors were outside our a priori defined clinically acceptable limits of ±3%. The incidence of falsely low-measured hematocrit was significantly higher with the presence of concomitant hypoalbuminemia and hypoproteinemia. Hypoalbuminemia combined with hyperglycemia showed significantly larger hematocrit measurement error. Hypoalbuminemia, hypoproteinemia, and hyperglycemia were predictors of falsely low-measured hematocrit. Furthermore, the overtransfusion group showed larger amount of transfusion than the adequately transfused group, with a median difference of 2 units (95% confidence interval [0-4], P = .039), despite similar amount of blood loss. CONCLUSIONS: Hematocrit measured using the POC device tends to be lower than the laboratory hematocrit measured during LT. Commonly encountered laboratory abnormalities during LT include hypoalbuminemia, hypoproteinemia, and hyperglycemia, which may contribute to falsely low-measured POC hematocrit. Careful consideration of these confounders may help reduce overtransfusion that occurs due to falsely low-measured POC hematocrit.

Determination of the 95% effective dose of remifentanil for the prevention of coughing during extubation in children undergoing tonsillectomy (with or without adenoidectomy).

BACKGROUND: Limited data are available regarding the 95% effective dose (ED95 ) of remifentanil to prevent the cough response during emergence from general anesthesia in children. METHODS: This study included 40 patients aged 3-12 years who underwent elective tonsillectomy with or without adenoidectomy. A predetermined remifentanil dose was infused continuously with desflurane during surgery and was continued until extubation. In the emergence period, the cough response during awake extubation was assessed to determine the remifentanil dose for the next patient. The first patient received remifentanil at the rate of 0.01 µg·kg(-1) ·min(-1) , and subsequent patients received a 0.01 µg·kg(-1) ·min(-1) higher dose than the previous patient if there was more than moderate coughing detected, and the patient after those with less than mild coughing received either the same dose (95% probability) or a 0.01 µg·kg(-1) ·min(-1) lower dose (5% probability) using the biased coin design. Times to extubation and adverse events were recorded. The ED95 was calculated using the maximum-likelihood estimation. RESULTS: The ED95 of remifentanil for preventing coughing during extubation was 0.060 µg·kg(-1) ·min(-1) (95% confidence interval, 0.037-0.068). There was moderate coughing in all groups receiving 0.01-0.06 µg·kg(-1) ·min(-1) of remifentanil, but no cough response occurred in the group receiving remifentanil 0.07 µg·kg(-1) ·min(-1) . Time to extubation was weakly correlated with remifentanil infusion rate (r = 0.331). One patient who received remifentanil 0.07 µg·kg(-1) ·min(-1) showed desaturation over 5 s immediately after extubation, but recovered after receiving 100% oxygen. CONCLUSION: The ED95 of the continuous remifentanil infusion rate was 0.060 µg·kg(-1) ·min(-1) to prevent the cough response during extubation in children after tonsillectomy.

Torsade de pointes in liver transplantation recipient after induction of general anesthesia: a case report.

Torsade de pointes (TdP) is an uncommon and specific form of polymorphic ventricular tachycardia, associated with a prolonged QT interval. Prolongation of the QT interval is the most widely recognized electrophysiological abnormality in patients with liver cirrhosis. We observed a case of TdP leading to cardiopulmonary resuscitation after the induction of general anesthesia, in a patient with liver cirrhosis scheduled for emergency cadaveric donor liver transplantation. The patient had mild QT prolongation on preoperative electrocardiography with a corrected QT (QTc) interval of 455 ms. Drugs used in the preoperative period can elongate cardiac repolarization. Sevoflurane and 5-hydroxytryptamine type 3 receptor antagonists such as palonsetron, used during general anesthesia may have triggered further QT prolongation, producing a fatal condition such as TdP. More caution and consideration in selecting drugs for anesthetic management are necessary for liver cirrhosis patients, especially in patients with preoperative QT prolongation.

Double-lumen tube placement with the patient in the supine position without a headrest minimizes displacement during lateral positioning.

PURPOSE: The correct position of double-lumen tubes (DLTs) is customarily confirmed after tracheal intubation by bronchoscopy with the patient supine on a headrest. However, displacement of DLTs usually occurs during lateral positioning because of neck extension. This study was undertaken to determine whether displacement of DLTs could be minimized during lateral positioning if DLTs were positioned without a headrest. METHODS: One hundred patients scheduled for thoracic surgery were randomized into two groups (n = 50 each). After tracheal intubation using a headrest, adjustment of DLT position was performed according to group assignment, i.e., either with the headrest in place or without the headrest. Using a bronchoscope, distances from the tracheal opening to the main carina and from the bronchial opening to the left bronchial carina were measured in both the supine and lateral positions. RESULTS: Displacement of DLTs [mean (standard deviation)] during lateral positioning was greater in the headrest group than in the no-headrest group [12.3 (6.5) mm vs 6.8 (5.5) mm, respectively, in the trachea; 11.6 (6.7) mm vs 6.0 (4.6) mm, respectively, in the bronchus; P < 0.001]. The incidence of significant displacement, defined as > 10 mm from initial correct position, was greater in the headrest group than in the no-headrest group (64% vs 28%, respectively, in the trachea; 58% vs 20%, respectively, in the bronchus; P < 0.001). CONCLUSION: Displacement of DLTs during lateral positioning appears to be caused primarily by extension of the neck. Correct adjustment of DLT position without a headrest in the supine position is an easy and effective method to minimize DLT displacement during lateral positioning.

Multiple extramedullary relapses without bone marrow involvement after second allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia.

EMR without BM involvement after allogeneic HSCT is extremely rare, especially in children; only a few cases have been reported. A two-yr-old boy was diagnosed with AML (M4) and underwent allogeneic HSCT in first complete remission with BM from HLA-matched unrelated donor without GVHD. Four yr later, he had a BM relapse and after induction and consolidation chemotherapy, he received a second HSCT from an unrelated donor using peripheral blood stem cells. His second post-transplant course was complicated by extensive chronic GVHD involving the skin, oral cavity, and lungs, which was treated with tacrolimus and corticosteroid. Two yr later, he noticed a mild swelling in the right cheek area. The BM showed a complete remission marrow and a soft tissue biopsy was compatible with granulocytic sarcoma. PET-CT showed multifocal bone involvements. He received chemotherapy, and the chloromas decreased in size. We report a case of diffuse EMR of AML without BM involvement after a second allogeneic HSCT.