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.

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.

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.

Bacterial chemistry-III: preliminary studies on trypanosomal activities of Chromobacterium violaceum products

It has been found that the pigment-I from Chromobacterium violaceum, 3-[1,2-dihydro5-(5-hydroxy-1H-indol-3-yl)-2-oxo-3H-pyrrol-3-yli diene] 1,3-dihydro-2H-indol-2-one, has trypanocide activity. The formylated derivatives, pigment-III, immobilized 100% of the Trypanosoma cruzi at a level of 46 microM after 48 h of interaction with a total growth inhibition in the same period. Pigment-I exhibited low toxicity and a DNA synthesis inhibition similar to that of Nifurtimox, a known trypanocide compound.