Anesthesia and analgesia
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Anesthesia and analgesia · May 2016
Comparative StudyThe Effect of Extracellular Calcium on Oxytocin-Induced Contractility in Naive and Oxytocin-Pretreated Human Myometrium In Vitro.
Prolonged exposure to oxytocin during augmentation of labor is a significant risk factor for uterine atony, resulting in the desensitization phenomenon, a decrease in the responsiveness of myometrium to further oxytocin. The importance of extracellular calcium is well established in spontaneous myometrial contractility; however, its significance is unknown in the context of desensitized myometrium. We aimed to investigate the effect of low, normal, and high extracellular calcium concentration on oxytocin-induced contractility in oxytocin-pretreated human myometrium in vitro. We hypothesized that extracellular normocalcemia would provide superior oxytocin-induced contractility in both naive and oxytocin-pretreated myometrium compared with hypocalcemia and hypercalcemia. ⋯ In oxytocin-naive myometrium, normocalcemia provides superior oxytocin-induced contractility compared with hypocalcemic and hypercalcemic conditions. We were unable to draw conclusions regarding oxytocin-pretreated myometrium because of the small sample size relative to the large variability of the data. These observations warrant further investigations in laboratory and clinical settings.
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Anesthesia and analgesia · May 2016
Comparative StudyThe Accuracy of Temperature Measurements Provided by the Edwards Lifesciences Pulmonary Artery Catheter.
Pulmonary artery catheters (PACs) are frequently used for monitoring patient temperatures in the intensive care unit. Nevertheless, data regarding the accuracy of these measurements are lacking, and few data testify to the accuracy of temperatures recorded after the PAC has been in place for several days. The absolute values of such measurements are relevant for critical care because patient temperatures are often used as diagnostic criteria for sepsis and antibiotic therapy. We thus hypothesized that the Edwards Lifesciences PAC would accurately measure blood temperature. To test our hypothesis, we compared temperature measurements obtained from PACs inserted in patients for different lengths of time with measurements of a reference platinum resistance thermometer (PRT). ⋯ We conclude that temperature measurements obtained using the Edwards Lifesciences PACs are thus sufficiently accurate to be used for clinical temperature monitoring in critically ill patients.
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Despite mixed results regarding the clinical utility of checklists, the anesthesia community is increasingly interested in advancing research around this important topic. Although several checklists have been developed to address routine perioperative care, few checklists in the anesthesia literature specifically target the management of trauma patients. We adapted a recently published "trauma and emergency checklist" for the initial phase of resuscitation and anesthesia of critically ill trauma patients into an applicable perioperative cognitive aid in the form of a pictogram that can be downloaded by the medical community. ⋯ A brief online survey is also presented to obtain feedback for improvement of this tool. The variability in utility of cognitive aids may be because of the specific clinical task being performed, the skill level of the individuals using the cognitive aid, overall quality of the cognitive aid, or organizational challenges. Once optimized, future research should be focused at ensuring successful implementation and customization of this tool.
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Anesthesia and analgesia · May 2016
Comparative StudyThe Effects of Lidocaine on Central Respiratory Neuron Activity and Nociceptive-Related Responses in the Brainstem-Spinal Cord Preparation of the Newborn Rat.
Lidocaine is widely used in the clinical setting as a local anesthetic and antiarrhythmic drug. Although it has been suggested that lidocaine exerts inhibitory effects on the central and peripheral neurons, there are no reports on its effects on central respiratory activity in vertebrates. In this study, we examined the effects of lidocaine on respiratory rhythm generation and nociceptive response in brainstem-spinal cord preparations from the newborn rats. ⋯ Our findings indicate that lidocaine depressed nociception-related responses at lower concentrations than those that induced respiratory depression. Our report provides the basic neuronal mechanisms to support the clinical use of lidocaine, which shows antinociceptive effects with minimal side effects on breathing.
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Anesthesia and analgesia · May 2016
Right Ventricular Longitudinal Strain Is Depressed in a Bovine Model of Pulmonary Hypertension.
Pulmonary hypertension and resulting right ventricular (RV) dysfunction are associated with significant perioperative morbidity and mortality. Although echocardiography permits real-time, noninvasive assessment of RV function, objective and comparative measures are underdeveloped, and appropriate animal models to study their utility are lacking. Longitudinal strain analysis is a novel echocardiographic method to quantify RV performance. Herein, we hypothesized that peak RV longitudinal strain would worsen in a bovine model of pulmonary hypertension compared with control animals. ⋯ Peak longitudinal RV strain detected worsened RV function in animals with hypoxia-induced pulmonary hypertension compared with control animals. This relationship was demonstrated in the transthoracic echocardiographic 4-chamber view independently for the RV free wall and for the combination of the free and septal walls. This innovative model of bovine pulmonary hypertension may prove useful to compare different monitoring technologies for the assessment of early events of RV dysfunction. Further studies linking novel RV imaging applications with mechanistic and therapeutic approaches are needed.