Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2011
ReviewIs ultrasound guidance advantageous for interventional pain management? A review of acute pain outcomes.
Ultrasound (US) guidance for peripheral nerve blockade has gained popularity worldwide. The reported benefits of real-time sonographic visualization compared with traditional nerve localization techniques generally apply to procedural and technical block-related outcomes whereas acute pain-related outcomes are featured less prominently. In this review, we evaluated the effect of US guidance compared with traditional nerve localization techniques for interventional management of acute pain and acute pain-related outcomes. ⋯ At present, there is insufficient evidence in the contemporary literature to define the effect of US guidance on acute pain and related outcomes compared with traditional nerve localization techniques for interventional acute pain management.
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Anesthesia and analgesia · Sep 2011
Randomized Controlled TrialThe effect of altering skin-surface cooling speeds on vasoconstriction and shivering thresholds.
Both core and skin temperatures contribute to steady-state thermoregulatory control. Dynamic thermoregulatory responses trigger aggressive defenses against rapid thermal perturbations. These responses potentially complicate interpretation of thermoregulatory studies and could slow induction of therapeutic hypothermia. We thus tested the hypothesis that rapid external skin-cooling triggers vasoconstriction and shivering at higher mean skin temperatures than slow or moderate rates of skin cooling. ⋯ Onset of vasoconstriction and shivering occurred at similar mean skin temperatures with all 3 cooling rates. Aggressive surface cooling can thus be used in thermoregulatory studies and for induction of therapeutic hypothermia without provoking dynamic thermoregulatory defenses.
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Anesthesia and analgesia · Sep 2011
Comparative StudyUltrasound assessment of the vertebral level of the intercristal line in pregnancy.
The intercristal line is known to most frequently cross the L4 spinous process or L4-5 interspace; however, it is speculated to be positioned higher during pregnancy because of the exaggerated lumbar lordosis. Clinical estimation of vertebral levels relying on the use of the intercristal line has been shown to often be inaccurate. We hypothesized that the vertebral level of the intercristal line determined by palpation would be higher than the level determined by ultrasound in pregnant women. ⋯ The anatomical position of the intercristal line was at L3 or higher in at least 6% of term pregnant patients using ultrasound. Clinical estimates were found to be ≥1 vertebral level higher than the anatomical position determined by ultrasound at least 40% of the time. This disparity may contribute to misidentification of lumbar interspaces and increased risk of neurologic injury during neuraxial anesthesia.
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Anesthesia and analgesia · Sep 2011
Randomized Controlled TrialAn intraoperative small dose of ketamine prevents remifentanil-induced postanesthetic shivering.
Patients undergoing gynecological laparotomy were randomized to receive either 0.5 mg/kg ketamine at induction of anesthesia followed by an infusion of 0.3 mg/kg/h until the end of surgery (ketamine group, n = 32), or an equivalent volume of normal saline (control group, n = 32). Anesthesia was maintained with IV propofol, a fixed infusion rate of remifentanil (0.25 μg/kg/min), and epidural ropivacaine. ⋯ The incidence of PAS was less frequent in the ketamine group (n = 2, 6%) compared with the control group (n = 12, 38%, P = 0.005). We conclude that, during the early recovery phase, intraoperative ketamine reduces remifentanil-induced PAS.
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Anesthesia and analgesia · Sep 2011
Comparative Study Clinical TrialEvaluation of a new software version of the FloTrac/Vigileo (version 3.02) and a comparison with previous data in cirrhotic patients undergoing liver transplant surgery.
Reliable cardiac output monitoring is particularly useful in the cirrhotic patient undergoing liver transplant surgery, because cirrhosis of the liver is associated with a vasodilated and high output state, known as cirrhotic cardiomyopathy, that challenges the reliability of pulse contour cardiac output technology. The contractility of the ventricle in cirrhosis is impaired, which is tolerated even though the ejection fraction and cardiac output are elevated because of the low peripheral resistance. However, during surgery the cirrhotic patient can decompensate because of the physiological changes and stress of surgery. Recently, we showed that the FloTrac/Vigileo™ failed to perform in cirrhotic patients undergoing transplant surgery. In response, the company upgraded their software. Therefore, we have assessed the accuracy and reliability of this new third-generation (version 3.02) FloTrac/Vigileo algorithm software in the same setting. ⋯ The new software (version 3.02) provided substantial improvements over the previous versions with better overall precision and trending ability. Further algorithm refinements will increase this technology's reliability to be extensively used in the highly complex setting of cirrhotic patients undergoing liver transplantation.