Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2011
Comparative StudyReinforcement learning versus proportional-integral-derivative control of hypnosis in a simulated intraoperative patient.
Research has demonstrated the efficacy of closed-loop control of anesthesia using bispectral index (BIS) as the controlled variable. Model-based and proportional-integral-derivative (PID) controllers outperform manual control. We investigated the application of reinforcement learning (RL), an intelligent systems control method, to closed-loop BIS-guided, propofol-induced hypnosis in simulated intraoperative patients. We also compared the performance of the RL agent against that of a conventional PID controller. ⋯ When compared with the PID controller, RL control resulted in slower induction but less overshoot and faster attainment of steady state. No difference in interindividual patient variation and noxious destabilizing challenge on control performance was observed between the 2 patient groups.
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Anesthesia and analgesia · Feb 2011
Do 0-10 numeric rating scores translate into clinically meaningful pain measures for children?
Self-reported pain scores are used widely in clinical and research settings, yet little is known about their interpretability in children. In this prospective, observational study we evaluated the relationship between 0 to 10 numerical rating scale (NRS) pain scores and other self-reported, clinically meaningful outcomes, including perceived need for medicine (PNM), pain relief (PR), and perceived satisfaction (PS) with treatment in children postoperatively. ⋯ This study provides important information regarding the clinical interpretation of NRS pain scores in children. Data further support the NRS as a valid measure of pain intensity in relation to the child's PNM, PR, and PS in the acute postoperative setting. However, the variability in scores in relation to other clinically meaningful outcomes suggests that application of cut-points for individual treatment decisions is inappropriate.
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Anesthesia and analgesia · Feb 2011
Combined catechol-O-methyltransferase and mu-opioid receptor gene polymorphisms affect morphine postoperative analgesia and central side effects.
Previous studies have generated controversial results regarding the influence of the genetic variations of μ-opioid receptors on morphine analgesia and opioid-related side effects in the postoperative period. Few studies have been conducted attempting to assess the combined effects of variation within ≥2 genes in relation to morphine response. In this study, we investigated whether combined catechol-O-methyltransferase and μ-opioid receptor polymorphisms contribute to the morphine response in postoperative analgesia. ⋯ This study has demonstrated the importance of the gene-gene approach in understanding the morphine response in patients after lower abdominal surgery. More studies are needed to characterize the combined effects of multiple genes and demographic as well as clinical variables in predicting the correct morphine dosage and corresponding opioid-related side effects.
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Anesthesia and analgesia · Feb 2011
Case ReportsReal-time three-dimensional ultrasound-guided central venous catheter placement.
We present the first description of real-time 3-dimensional ultrasound for insertion of a central venous catheter in a surgical patient. An HD11 XE™ ultrasound machine with a V8-4 transducer (Philips Medical Systems, Bothell, WA) was used throughout. Three-dimensional multiplanar and volume-rendered views allowed us to simultaneously view the neck anatomy in 3 orthogonal planes. ⋯ We were able to rotate the views in real time, thereby enabling visualization of the catheter within the lumen of the vein. The ability to see simultaneous real-time short- and long-axis views along with volume perspective without altering transducer position is an exciting development with the potential to confer a safety benefit to the patient. Although the operator is required to assimilate more information, the limitations we encountered were mainly related to processing power and transducer size, which we expect will be overcome with advancing technology.
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Anesthesia and analgesia · Feb 2011
Endoscopic strip craniectomy in early infancy: the initial five years of anesthesia experience.
Minimally invasive endoscopic strip craniectomy (ESC) is a relatively new surgical technique for treating craniosynostosis in early infancy. In this study we reviewed our anesthesia experience with ESC. The hypothesis was that infants with low body weight and syndromes would have a higher risk of perioperative blood transfusion and that those with respiratory complications are more likely to be admitted to the intensive care unit (ICU). ⋯ Twenty percent of infants undergoing ESC had 1 or more of the following: need for blood transfusion, VAE, respiratory complications, and ICU admission. Multivariable analysis confirmed that patients with lower body weight, those with earlier date of surgery in the series, those undergoing sagittal ESC, and those with syndromic craniosynostosis had a higher rate of blood transfusion. ICU admissions often occurred in infants requiring transfusion and those with respiratory complications. Infants with multiple-suture craniosynostosis were more likely to require subsequent craniofacial reconstruction procedures.