Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2012
Randomized Controlled Trial Comparative StudyCerebrospinal fluid neurotransmitter changes during the perioperative period in patients undergoing total knee replacement: a randomized trial.
Total knee replacement (TKR) is of enormous benefit to patients with osteoarthritis of the knee; however, the acute postoperative pain can be severe and difficult to manage. The role of major spinal cord neurotransmitters in this acute postoperative period is not clear, although there are a few studies in humans. We performed the first prospective clinical study undertaken to delineate the changes in the spinal neurotransmitters after a surgery such as TKR. Furthermore, we also determined whether antihyperalgesic drugs at clinically acceptable doses modulate spinal neurotransmitter concentrations in patients during the perioperative period. ⋯ In the perioperative period, the concentration changes of the 4 spinal neurotransmitters have a distinct time course. CSF substance P seems to increase very rapidly with surgical intervention, whereas the CSF norepinephrine concentration tends to decrease. At clinical doses, pregabalin does not seem to modulate these spinal neurotransmitter concentrations.
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Anesthesia and analgesia · Feb 2012
Oxytocin inhibits the membrane depolarization-induced increase in intracellular calcium in capsaicin sensitive sensory neurons: a peripheral mechanism of analgesic action.
Lumbar intrathecal injection of oxytocin produces antinociception in rats and analgesia in humans. Classically, oxytocin receptors couple to stimulatory G proteins, increase inositol-3-phosphate production, and result in neuronal excitation. Most work to date has focused on a spinal site of oxytocin to excite γ-aminobutyric acid interneurons to produce analgesia. Here we ask whether oxytocin might also affect primary sensory afferents by modulating high voltage-gated calcium channels, such as it does in the brain. ⋯ These data suggest that oxytocin produces antinociception after intrathecal delivery in part by reducing excitatory neurotransmitter release from the central terminals of nociceptors.
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Anesthesia and analgesia · Feb 2012
ReviewProcoagulant activity in hemostasis and thrombosis: Virchow's triad revisited.
Virchow's triad is traditionally invoked to explain pathophysiologic mechanisms leading to thrombosis, alleging concerted roles for abnormalities in blood composition, vessel wall components, and blood flow in the development of arterial and venous thrombosis. Given the tissue-specific bleeding observed in hemophilia patients, it may be instructive to consider the principles of Virchow's triad when investigating mechanisms operant in hemostatic disorders as well. Blood composition (the function of circulating blood cells and plasma proteins) is the most well studied component of the triad. ⋯ That no one abnormality in any component of Virchow's triad fully predicts coagulopathy a priori suggests coagulopathies are complex, multifactorial, and interactive. In this review, we focus on contributions of blood composition, vascular cells, and blood flow to hemostasis and thrombosis, and suggest that cross-talk among the 3 components of Virchow's triad is necessary for hemostasis and determines propensity for thrombosis or bleeding. Investigative models that permit interplay among these components are necessary to understand the operant pathophysiology, and effectively treat and prevent thrombotic and bleeding disorders.
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Anesthesia and analgesia · Feb 2012
Randomized Controlled Trial Comparative StudyContinuous epicapsular ropivacaine 0.3% infusion after minimally invasive hip arthroplasty: a prospective, randomized, double-blinded, placebo-controlled study comparing continuous wound infusion with morphine patient-controlled analgesia.
In this study, we investigated the impact of a continuous wound infusion with ropivacaine 0.3% on pain and morphine consumption after minimally invasive hip arthroplasty. ⋯ Continuous epicapsular wound infusion with ropivacaine 0.3% after minimally invasive hip replacement is an efficient technique for reducing morphine consumption and improving the quality of postoperative analgesia. The beneficial effects of this technique are still present 3 months after surgery.
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Anesthesia and analgesia · Feb 2012
Randomized Controlled TrialEsophageal guidewire-assisted nasogastric tube insertion in anesthetized and intubated patients: a prospective randomized controlled study.
Nasogastric tube (NGT) insertion is indicated almost routinely in patients undergoing abdominal surgery to decompress the stomach intraoperatively and postoperatively, and to allow postoperative tube feeding. NGTs are made of nonreinforced polymer plastic materials and are prone to kinking and coiling during insertion. This often poses difficulty in blind NGT placement or placement assisted by variously described techniques. We hypothesized that esophageal guidewire-assisted NGT insertion with manual forward laryngeal displacement can significantly improve the first-attempt success rate over the technique of head flexion and lateral neck pressure during its insertion in anesthetized and tracheally intubated patients. ⋯ Esophageal guidewire-assisted insertion with manual forward laryngeal displacement technique most frequently resulted in correct positioning of the NGT in anesthetized and tracheally intubated patients after the first attempt. This technique is also associated with a lower incidence of procedure-related injuries and is less time-consuming than conventional insertion techniques.