Water in the human body: An anesthesiologist's perspective on the connection between physicochemical properties of water and physiologic relevance.

The unique structure and multifaceted physicochemical properties of the water molecule, in addition to its universal presence in body compartments, make water a key player in multiple biological processes in human physiology. Since anesthesiologists deal with physiologic processes where water molecules are critical at different levels, and administer medications whose pharmacokinetics and pharmacodynamics depend on interaction with water molecules, we consider that exploration of basic science aspects related to water and its role in physiology and pharmacology is relevant to the practice of anesthesiology. The purpose of this paper is to delineate the physicochemical basis of water that are critical in enabling it to support various homeostatic processes. The role of water in the formation of solutions, modulation of surface tension and in homeostasis of body temperature, acid-base status and osmolarity, is analyzed. Relevance of molecular water interactions to the anesthesiologist is not limited to the realm of physiology and pathophysiology. Deep knowledge of the importance of water in volatile anesthetic effects on neurons opens a window to a new comprehensive understanding of complex cellular mechanisms underlying the practice of anesthesiology.

Utility and Clinical Profile of Dexmedetomidine in Pediatric Cardiac Catheterization Procedures: A Matched Controlled Analysis.

BACKGROUND: Dexmedetomidine is increasingly used in children undergoing cardiac catheterization procedures. We compared the percentage of surgical time with hemodynamic instability and the incidence of postoperative agitation between pediatric cardiac catheterization patients who received dexmedetomidine infusion and those who did not and the incidence of postoperative agitation. MATERIALS AND METHODS: We matched 653 pediatric patients scheduled for cardiac catheterization. Two separate multivariable linear mixed models were used to assess the association between dexmedetomidine use and intraoperative blood pressure and heart rate instability. A multivariate logistic regression was used for relationship between dexmedetomidine and postoperative agitation. RESULTS: No difference between the study groups was found in the duration of MAP ( P = .867) or heart rate (HR) instabilities ( P = .224). The relationship between dexmedetomidine use and the duration of negative hemodynamic effects does not depend on any of the considered CHD types (all P > .001) or intervention ( P = .453 for MAP and P = .023 for HR). No difference in postoperative agitation was found between the study groups ( P = .590). CONCLUSION: Our study demonstrated no benefit in using dexmedetomidine infusion compared with other general anesthesia techniques to maintain hemodynamic stability or decrease agitation in pediatric patients undergoing cardiac catheterization procedures.

Mathematical Analysis and Physical Profile of Blalock-Taussig Shunt and Sano Modification Procedure in Hypoplastic Left Heart Syndrome: Review of the Literature and Implications for the Anesthesiologist.

The first stage of surgical treatment for hypoplastic left heart syndrome (HLHS) includes the creation of artificial systemic-to-pulmonary connections to provide pulmonary blood flow. The modified Blalock-Taussig (mBT) shunt has been the technique of choice for this procedure; however, a right ventricle-pulmonary artery (RV-PA) shunt has been introduced into clinical practice with encouraging but still conflicting outcomes when compared with the mBT shunt. The aim of this study is to explore mathematical modeling as a tool for describing physical profiles that could assist the surgical team in predicting complications related to stenosis and malfunction of grafts in an attempt to find correlations with clinical outcomes from clinical studies that compared both surgical techniques and to assist the anesthesiologist in making decisions to manage patients with this complex cardiac anatomy. Mathematical modeling to display the physical characteristics of the chosen surgical shunt is a valuable tool to predict flow patterns, shear stress, and rate distribution as well as energetic performance at the graft level and relative to ventricular efficiency. Such predictions will enable the surgical team to refine the technique so that hemodynamic complications be anticipated and prevented, and are also important for perioperative management by the anesthesia team.

Anesthesiology residents' perception of educational environment: comparison between different years of training.

STUDY OBJECTIVES: To assess whether the year of residency in anesthesiology is associated with residents' overall perceptions of the learning environment and to evaluate the association between year of residency and each of the five domains of the Dundee Ready Education Environment Measure (DREEM) survey. DESIGN: Cross-sectional study. SETTING: Residency program of anesthesiology at the Cleveland Clinic. SUBJECTS AND INTERVENTION: Residents of anesthesiology at the Cleveland Clinic were invited to complete the DREEM questionnaire and a demographic survey. MEASUREMENTS: We assessed whether year of residency was associated with the overall standardized DREEM questionnaire score using linear regression. We also assessed the associations between year of residency and each of the 5 DREEM questionnaire domains using separate linear regression models. RESULTS: Of the 60 residents invited to complete the DREEM questionnaire, 49 (82%) completed it. There was no association between year of residency and overall DREEM score (P = .21), students' perception of teaching (P = .38), students' perceptions of teachers (P = .28), students' academic self-perceptions (P = .03), students' perceptions of atmosphere (P = .65), or students' social self-perceptions (P = .08). The primary outcome was assessed using a significance criterion of 0.05, whereas each secondary outcome was assessed using a significance criterion of 0.01 for secondary analyses (ie, 0.05/5, Bonferroni). CONCLUSION: Resident's perception of the learning environment in the anesthesiology residency program of the Cleveland Clinic is on the positive side, as measured by the DREEM questionnaire. We found no association between the year of training and the DREEM questionnaire overall score. Furthermore, we found no association between year of residency and any of the subscores for the 5 DREEM domains. There is room for improvement, especially in the area of self-perception.

Multisource feedback in professionalism for anesthesia residents.

STUDY OBJECTIVE: To assess professionalism in anesthesiology residents, it is important to obtain evaluations from people with whom they interact on daily basis. The purpose of this study was to evaluate the effect of a Multisource feedback (MSF) on resident's professional behavior and to assess the effect of faculty feedback on resident performance. DESIGN: This study was a two-group randomized clinical trial. SETTING: Residents were recruited from Cleveland Clinic Children's Hospital. PATIENTS: Participants included twenty eight residents doing a two-month rotation in Pediatric Anesthesia. INTERVENTIONS: Multisource feedback questionnaires were developed and then validated using face and content validity. Residents were randomly assigned to a feedback group or a control group. Both groups received the MSF evaluation. Only the group assigned to feedback had a 'coaching meeting' every month creating strategies for improvement. MEASUREMENTS: MSF questionnaires were validated using a face validation and expert content validity. The effect of MSF on a professionalism questionnaire was assessed using analysis of covariance and linear mixed effects regression models. MAIN RESULTS: Observed test-retest agreement was greater than 0.90 for all items, with more than half of kappa statistics greater than 0.50. Cronbach's alpha was 0.71.The MSF increased the self-assessment score with an estimated effect of 0.21 (95% CI 0.06, 0.37), P=.015. There was no detected effect on patient family evaluation, with mean difference (CI) in change from baseline of 0.03 (-0.15, 0.21), P=.77, faculty evaluation, 0.21 (-0.02, 0.44), P=.08, or coworker evaluation 0.13 (-0.11, 0.37). CONCLUSIONS: Our new multi-source feedback questionnaire to assess professionalism had good reliability and internal consistency. Using our validated questionnaire we assessed the effect of a monthly feedback to improve professionalism in anesthesia residents. While we did see improvement in anesthesiology residents' self-assessment, we did not see a similar effect on patient family, faculty or coworker evaluations.

Perioperative Considerations for Children With Right Ventricular Dysfunction and Failing Fontan.

The survival of patients with congenital heart diseases (CHD) has increased in the past decades, resulting in the identification of new characteristics of chronic comorbidities observed in pediatric and adults with CHD. Patients with CHD can present with a broad clinical spectrum of manifestations of congestive heart failure (CHF) at any point throughout their lives that may be related to anatomical or surgical variables. This article focuses on the perioperative assessment of patients with CHD and CHF, with an emphasis on pathophysiologic, diagnostic, and therapeutic alternatives in patients with right ventricular failure and failing Fontan circulation. We also provide descriptions of the effects of sedatives and anesthetics commonly used in this population in diagnostic or invasive procedures.

Comparison of the Truview PCD™ and the GlideScope(®) video laryngoscopes with direct laryngoscopy in pediatric patients: a randomized trial.

INTRODUCTION: The GlideScope(®) video laryngoscope has a 60° angled blade and the blade of the Truview PCD™ video laryngoscope has an optical lens that provides a 46° refraction of the viewing angle. Despite successful results using the GlideScope in adults, few studies have been published regarding its use in pediatric patients. We therefore tested our joint primary hypothesis that the GlideScope and the Truview PCD video laryngoscopes provide superior visualization to direct laryngoscopy and are non-inferior regarding time to intubation. METHODS: One hundred thirty-four patients (neonate to ten years of age, American Society of Anesthesiologists physical status I-III) scheduled for general surgical procedures were randomized to tracheal intubation using the Truview PCD or GlideScope video laryngoscope or direct laryngoscopy (Macintosh blade). The laryngoscopic view was scored using the Cormack-Lehane scale. Time to intubation (defined as the time from the moment the device entered the patient's mouth until end-tidal CO2 was detected) and the number of attempts were recorded. RESULTS: The Cormack-Lehane views attained using the GlideScope (P > 0.99) and Truview PCD (P = 0.18) were not superior to the views attained with direct laryngoscopy. Furthermore, the view attained using the GlideScope was significantly worse than that attained using direct laryngoscopy (P < 0.001). Fewer patients showed Cormack-Lehane grade I views with the GlideScope than with the Truview PCD (14% vs 82%, respectively; 95% confidence interval [CI] -91% to -46%). The observed median [Q1, Q3] times to intubation were: 39 [31, 59] sec, 44 [28, 62] sec, and 23 [21, 28] sec with the GlideScope, Truview PCD, and direct laryngoscopy, respectively, with median differences of 14 sec (95% CI 7 to 26, GlideScope - direct laryngoscopy) and 17 sec (95% CI 6 to 28, Truview PCD - direct laryngoscopy). CONCLUSION: The Cormack-Lehane views attained using the GlideScope and the Truview PCD video laryngoscopes were not superior to views attained using direct laryngoscopy. Visualization with the GlideScope was significantly worse than with direct laryngoscopy. Use of the GlideScope and Truview PCD systems should be restricted to patients with specific indications.