Risk factors for intraoperative allogeneic blood transfusion during craniotomy for brain tumor removal in children.

BACKGROUND: Several clinical and surgical factors can influence the occurrence of allogeneic blood transfusion (ABT) during oncologic neurosurgery. OBJECTIVES: To identify the potential predictive factors of ABT during craniotomy for the removal of brain tumors in children and the potential impact of intraoperative ABT on early postoperative outcome. METHODS: A retrospective study was performed in all pediatric patients younger than 18 years who underwent craniotomy for brain tumor removal from December 2009 to December 2012 in our institution. Pre-, intra-, and postoperative data were collected from medical and stored electronic anesthesia records. The predictors of intraoperative ABT were determined using multivariate logistic regression. RESULTS: A total of 110 patients were included. Twenty-seven patients (25%) received intraoperative ABT with a volume of 16 ± 8 ml·kg(-1) . On multivariate analysis, an age <4 years, a duration of surgery >270 min, and a preoperative hemoglobin <12.2 g·dl(-1) were independently associated with the need for intraoperative ABT. We did not show any significant difference concerning postoperative early outcome and length of stay between the transfused and non-transfused patients except for the duration of postoperative mechanical ventilation that was significantly higher in the transfused group (P = 0.04). CONCLUSION: In children, craniotomy for brain tumor removal is at risk of intraoperative ABT. An age <4 years, a duration of surgery >270 min, and a preoperative hemoglobin <12.2 g·dl(-1) are the main factors associated with intraoperative ABT during this surgery.

Pitfalls in chronobiology: a suggested analysis using intrathecal bupivacaine analgesia as an example.

BACKGROUND: The duration of analgesia from epidural administration of local anesthetics to parturients has been shown to follow a rhythmic pattern according to the time of drug administration. We studied whether there was a similar pattern after intrathecal administration of bupivacaine in parturients. In the course of the analysis, we came to believe that some data points coincident with provider shift changes were influenced by nonbiological, health care system factors, thus incorrectly suggesting a periodic signal in duration of labor analgesia. We developed graphical and analytical tools to help assess the influence of individual points on the chronobiological analysis. METHODS: Women with singleton term pregnancies in vertex presentation, cervical dilation 3 to 5 cm, pain score >50 mm (of 100 mm), and requesting labor analgesia were enrolled in this study. Patients received 2.5 mg of intrathecal bupivacaine in 2 mL using a combined spinal-epidural technique. Analgesia duration was the time from intrathecal injection until the first request for additional analgesia. The duration of analgesia was analyzed by visual inspection of the data, application of smoothing functions (Supersmoother; LOWESS and LOESS [locally weighted scatterplot smoothing functions]), analysis of variance, Cosinor (Chronos-Fit), Excel, and NONMEM (nonlinear mixed effect modeling). Confidence intervals (CIs) were determined by bootstrap analysis (1000 replications with replacement) using PLT Tools. RESULTS: Eighty-two women were included in the study. Examination of the raw data using 3 smoothing functions revealed a bimodal pattern, with a peak at approximately 0630 and a subsequent peak in the afternoon or evening, depending on the smoother. Analysis of variance did not identify any statistically significant difference between the duration of analgesia when intrathecal injection was given from midnight to 0600 compared with the duration of analgesia after intrathecal injection at other times. Chronos-Fit, Excel, and NONMEM produced identical results, with a mean duration of analgesia of 38.4 minutes (95% CI: 35.4-41.6 minutes), an 8-hour periodic waveform with an amplitude of 5.8 minutes (95% CI: 2.1-10.7 minutes), and a phase offset of 6.5 hours (95% CI: 5.4-8.0 hours) relative to midnight. The 8-hour periodic model did not reach statistical significance in 40% of bootstrap analyses, implying that statistical significance of the 8-hour periodic model was dependent on a subset of the data. Two data points before the change of shift at 0700 contributed most strongly to the statistical significance of the periodic waveform. Without these data points, there was no evidence of an 8-hour periodic waveform for intrathecal bupivacaine analgesia. CONCLUSION: Chronobiology includes the influence of external daily rhythms in the environment (e.g., nursing shifts) as well as human biological rhythms. We were able to distinguish the influence of an external rhythm by combining several novel analyses: (1) graphical presentation superimposing the raw data, external rhythms (e.g., nursing and anesthesia provider shifts), and smoothing functions; (2) graphical display of the contribution of each data point to the statistical significance; and (3) bootstrap analysis to identify whether the statistical significance was highly dependent on a data subset. These approaches suggested that 2 data points were likely artifacts of the change in nursing and anesthesia shifts. When these points were removed, there was no suggestion of biological rhythm in the duration of intrathecal bupivacaine analgesia.

Hemofiltration with the Cascade system in an experimental porcine model of septic shock.

High-volume hemofiltration (HVHF) has been suggested as an adjuvant treatment of septic shock because of its capacities to remove inflammatory mediators from blood. Nevertheless, HVHF presents some important drawbacks, such as the depletion of low molecular weight molecules (nutriments, vitamins, trace elements and antibiotics) due to the high ultrafiltration rate, or the significant financial cost and nursing workload due to the frequent changes of large amounts of expensive sterile substitution fluids. A new hemofiltration system called "Cascade" has been developed, allowing very high ultrafiltration rates (120 mL/kg/h) limiting these drawbacks by using a special extracorporeal circuit. The objective of this study was to assess the technical feasibility of the Cascade system and to compare its hemodynamic impact to that of the standard HVHF system. Twenty sepsis-induced pigs were randomized in two groups: one group was hemofiltered with the standard HVHF system and the other with the Cascade system during a six-hour session. No technical problems were observed with the Cascade system during the experiment. At the end of the experiment, colloid requirements (989 +/- 355 mL vs. 1913 +/- 538 mL, P = 0.006), epinephrine requirements (0.82 +/- 0.42 mg vs. 3.27 +/- 3.02 mg, P < 0.001), lactic acidosis (pH = 7.33 +/- 0.08 vs. 7.10 +/- 0.07, P < 0.001) and mean pulmonary arterial pressure were less pronounced in the Cascade group. These results suggest that Cascade hemofiltration is technically feasible and safe. Moreover, compared with standard HVHF, it can reduce the severity of porcine septic shock.

Laryngeal injuries and intubating conditions with or without muscular relaxation: an equivalence study.

PURPOSE: The need for muscular relaxation to improve intubating conditions and to reduce the incidence of laryngeal morbidity is still controversial. The aim of this study was to determine the incidence of symptomatic laryngeal injuries (SLI) and of acceptable intubating conditions (including both good and excellent conditions), both with and without cisatracurium during induction of anesthesia, along with moderate doses of remifentanil and propofol. METHODS: In this prospective, randomized double-blind equivalence trial, the intubating conditions were compared in 130 ASA I or II female patients. All subjects received remifentanil 2 microg x kg(-1) i.v. and propofol 2.5 mg x kg(-1) i.v., with either cisatracurium 0.15 mg x kg(-1) i.v. (group Cisatracturium), or saline (group Placebo). Tracheal intubating conditions were assessed with the Copenhagen Score. A systematic screening for postoperative hoarseness and sore throat was performed 24 and 48 hr after anesthesia, followed by a nasofibroscopic examination when laryngeal symptoms persisted at 48 hr. RESULTS: Twenty-four hr after anesthesia, the incidence of postoperative hoarseness and sore throat in the Cisatracurium and Placebo groups was 26.5% and 21.5%, respectively, and 48 hr after anesthesia, the incidence was 7.8% and 6.1%, respectively (P = 0.32 and P = 0.50 between groups, respectively). In the clinically evaluable population, the incidence of SLI, assessed at 48 hr by nasofibroscopy, was equivalent in both groups, 1.6% vs 1.5% in group Placebo and group Cisatracurium, respectively (P < 0.001 for equivalence test), as was the occurrence of acceptable intubating conditions (95.4% vs 100%, P < 0.05 for equivalence test). However, the occurrence of excellent intubating conditions was more frequent in group Cisatracurium than in group Placebo (P = 0.0003). CONCLUSION: Following induction of anesthesia with propofol and moderate-dose remifentanil, cisatracurium did not confer a higher rate of good-to-excellent conditions for tracheal intubation, nor did muscle relaxation with cisatracurium decrease the rate of SLI after tracheal intubation.