Anesthesia and analgesia
-
Anesthesia and analgesia · May 2018
ReviewCorrelation Coefficients: Appropriate Use and Interpretation.
Correlation in the broadest sense is a measure of an association between variables. In correlated data, the change in the magnitude of 1 variable is associated with a change in the magnitude of another variable, either in the same (positive correlation) or in the opposite (negative correlation) direction. Most often, the term correlation is used in the context of a linear relationship between 2 continuous variables and expressed as Pearson product-moment correlation. ⋯ Both correlation coefficients are scaled such that they range from -1 to +1, where 0 indicates that there is no linear or monotonic association, and the relationship gets stronger and ultimately approaches a straight line (Pearson correlation) or a constantly increasing or decreasing curve (Spearman correlation) as the coefficient approaches an absolute value of 1. Hypothesis tests and confidence intervals can be used to address the statistical significance of the results and to estimate the strength of the relationship in the population from which the data were sampled. The aim of this tutorial is to guide researchers and clinicians in the appropriate use and interpretation of correlation coefficients.
-
Anesthesia and analgesia · May 2018
Randomized Controlled TrialEffect of Stellate Ganglion Block on the Regional Hemodynamics of the Upper Extremity: A Randomized Controlled Trial.
The success of stellate ganglion block (SGB) is traditionally determined on the basis of findings such as Horner's syndrome, temperature rise in the face, hyperemia of the tympanic membrane, and nasal congestion. However, decreases in vascular resistance and increases in blood flow in the arm may be more meaningful findings. To date, the effect of SGB on the regional hemodynamics of the arm has not been evaluated using pulsed-wave Doppler ultrasound. ⋯ Although SGB did not decrease the pain associated with forearm surgery, ultrasound-guided SGB did increase blood flow and decrease vascular resistance in the arm. Therefore, pulsed-wave Doppler may be used to monitor the success of SGB.
-
Anesthesia and analgesia · May 2018
Predicting Heparin Responsiveness in Children Before Cardiopulmonary Bypass: A Retrospective Cohort Study.
Inadequate or excess administration of unfractionated heparin for cardiopulmonary bypass (CPB) can cause significant harm. Age-dependent differences in the pharmacodynamics and pharmacokinetics of heparin contribute to increased variability of heparin responsiveness in children. The aims of the current study were to (1) examine the correlation between predicted and observed heparin responsiveness in children before CPB measured using the Hemostasis Management System (HMS) Plus (Medtronic, Minneapolis, MN), (2) describe age-specific reference intervals for heparin sensitivity index (HSI) observed in children, and (3) test predictive models of HSI using preoperative clinical and laboratory data. ⋯ In a large cohort of children, heparin responsiveness before CPB was not reliably predicted by either in vitro measurement using the HMS Plus System or commonly available preoperative clinical and laboratory data. We describe age-specific reference intervals for HSI in children, and we anticipate that these data will aid the identification of heparin resistance in this population.
-
Anesthesia and analgesia · May 2018
Differential Effects of Anesthetics and Opioid Receptor Activation on Cardioprotection Elicited by Reactive Oxygen Species-Mediated Postconditioning in Sprague-Dawley Rat Hearts.
Despite an array of cardioprotective interventions identified in preclinical models of ischemia-reperfusion (IR) injury, successful clinical translation has not been achieved. This study investigated whether drugs routinely used in clinical anesthesia influence cardioprotective effectiveness by reducing effects of reactive oxygen species (ROS), upstream triggers of cardioprotective signaling. Effects of propofol, sevoflurane, or remifentanil were compared on postischemic functional recovery induced by ROS-mediated postconditioning with Intralipid. ⋯ These divergent effects of routinely used drugs in clinical anesthesia may influence the translatability of cardioprotective therapies such as Intralipid postconditioning.