Crystalloid versus Colloid for Intraoperative Goal-directed Fluid Therapy Using a Closed-loop System: A Randomized, Double-blinded, Controlled Trial in Major Abdominal Surgery.

BACKGROUND: The type of fluid and volume regimen given intraoperatively both can impact patient outcome after major surgery. This two-arm, parallel, randomized controlled, double-blind, bi-center superiority study tested the hypothesis that when using closed-loop assisted goal-directed fluid therapy, balanced colloids are associated with fewer postoperative complications compared to balanced crystalloids in patients having major elective abdominal surgery. METHODS: One hundred and sixty patients were enrolled in the protocol. All patients had maintenance-balanced crystalloid administration of 3 ml · kg · h. A closed-loop system delivered additional 100-ml fluid boluses (patients were randomized to receive either a balanced-crystalloid or colloid solution) according to a predefined goal-directed strategy, using a stroke volume and stroke volume variation monitor. All patients were included in the analysis. The primary outcome was the Post-Operative Morbidity Survey score, a nine-domain scale, at day 2 postsurgery. Secondary outcomes included all postoperative complications. RESULTS: Patients randomized in the colloid group had a lower Post-Operative Morbidity Survey score (median [interquartile range] of 2 [1 to 3] vs. 3 [1 to 4], difference -1 [95% CI, -1 to 0]; P < 0.001) and a lower incidence of postoperative complications. Total volume of fluid administered intraoperatively and net fluid balance were significantly lower in the colloid group. CONCLUSIONS: Under our study conditions, a colloid-based goal-directed fluid therapy was associated with fewer postoperative complications than a crystalloid one. This beneficial effect may be related to a lower intraoperative fluid balance when a balanced colloid was used. However, given the study design, the mechanism for the difference cannot be determined with certainty.

Clonidine administration during intraoperative monitoring for pediatric scoliosis surgery: Effects on central and peripheral motor responses.

OBJECTIVE: To study the effect of clonidine administrated as a co-analgesic during scoliosis surgery, on the neuromonitoring of spinal motor pathways. METHODS: Using standardized intraoperative monitoring, we compared the time course of peripherally and transcranially electrically evoked motor potentials (TcEMEPs) before and after injection of a single bolus of clonidine in children under total intravenous anesthesia (TIVA). MEP data were obtained from 9 patients and somatosensory evoked potentials (SSEPs) were obtained from 2 patients. The potential effect of clonidine on mean blood pressure (BP) was controlled. RESULTS: TcEMEPs from upper and lower limbs rapidly showed significant drops in amplitude after the injection of clonidine. Amplitudes reached minimal values within five minutes and remained very weak for at least 10-20minutes during which monitoring of the central motor pathways was severely compromised. SSEPs were not altered during maximal amplitude depression of the TcEMEPS. CONCLUSIONS: This is the first report showing that clonidine severely interferes with neuromonitoring of the spinal cord motor pathways. The results are discussed in light of the literature describing the effects of dexmedetomidine, another α-2 adrenergic agonist. The experimental and literature data point to central mechanisms taking place at both the spinal and cerebral levels. Therefore, clonidine as well as other α-2 adrenergic agonists should be used with extreme caution in patients for whom neuromonitoring of the motor pathways is required during surgery.

Ultrasound guided internal jugular vein access in children and infant: a meta-analysis of published studies.

INTRODUCTION: Central venous catheter placement is technically difficult in pediatric population especially in the younger patients. Ultrasound prelocation and/or guidance (UPG) of internal jugular vein (IJV) access has been shown to decrease failure rate and complications related to this invasive procedure. The goal of the present study was to perform a systematic review of the advantages of UPG over anatomical landmarks (AL) during IJV access in children and infants. MATERIAL AND METHODS: A comprehensive literature search was conducted to identify clinical trials that focused on the comparison of UPG to AL techniques during IJV access in children and infants. Two reviewers independently assessed each study to meet inclusion criteria and extracted data. Data from each trial were combined to calculate the pooled odds ratio (OR) or the mean differences (MD), and their 95% confidence intervals [CI 95%]. I(2) statistics were used to assess statistics heterogeneity and to guide the use of fixed or random effect for computation of overall effects. Subgroup analysis was used to clarify the effects of the techniques used (prelocation or guidance) or the experience of practitioners. RESULTS: Literature found five articles. Most of the patients were cardiac surgery patients. In comparison with AL, UPG had no effect on IJV access failure rate (OR = 0.28 [0.05, 1.47], I(2) = 75%, P = 0.003), the rate of carotid artery puncture (OR = 0.32 [0.06, 1.62], I(2) = 68%, P = 0.01), haematoma, haemothorax, or pneumothorax occurrence (OR = 0.40 [0.14, 1.13], I(2) = 17%, P = 0.30, OR = 0.72, OR = 0.81 [0.18, 3.73], I(2) = 0%, P = 0.94, respectively) and time to IJV access and haemothorax/pneumothorax occurrence. Subgroup analysis found an efficacy of ultrasound when used by novice operators or during intraoperative use. DISCUSSION: This current meta-analysis does not found the utility of ultrasound during IJV access in children and infants in increasing the success rate and in decreasing complications.