Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2005
Randomized Controlled Trial Clinical TrialSmall-dose bupivacaine-sufentanil prevents cardiac output modifications after spinal anesthesia.
Spinal injection of small-dose (SD) bupivacaine decreases the likelihood of hypotension compared with large-dose (LD) bupivacaine. We assumed that a SD of bupivacaine could also prevent the decrease in cardiac output (CO). Patients undergoing elective urologic, lower abdominal, or lower limb surgery under spinal anesthesia were included in this prospective randomized study. ⋯ CO was higher in the SD group as compared with the LD group from 2 min to 30 min after spinal anesthesia. Moreover, CO increased at 2 min in the SD group and decreased at 10 and 30 min in the LD group compared with baseline value. In conclusion, SD bupivacaine provides successful anesthesia and gives better CO stability than LD.
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Anesthesia and analgesia · Nov 2005
Nitric oxide is not a mediator of inflammation-induced resistance to atracurium.
Resistance to atracurium as a result of increased drug binding to alpha1-acid glycoprotein is associated with increased inducible nitric oxide synthase activity and increased nitric oxide levels in plasma. We investigated if the inhibition of inducible nitric oxide synthase and suppression of nitric oxide can reverse the resistance to atracurium. As a model of alpha1-acid glycoprotein and nitric oxide increase, 84 male Sprague-Dawley rats received an IV injection of either 60 mg/kg Corynebacterium parvum (CP) or saline (control). ⋯ In the CP groups, N-Iminolysine suppressed nitric oxide levels in a dose-dependent manner. Resistance to atracurium persisted. alpha1-acid glycoprotein serum levels remained increased in all CP groups with no differences in acetylcholine receptor expression. Our results suggest that the mechanism leading to increased expression of alpha1-acid glycoprotein and consecutive increased protein binding of atracurium is not mediated by inducible nitric oxide synthase induction and nitric oxide expression.
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Anesthesia and analgesia · Nov 2005
Doxapram only slightly reduces the shivering threshold in healthy volunteers.
We determined the effects of doxapram on the major autonomic thermoregulatory responses in humans. Nine healthy volunteers were studied on 2 days: control and doxapram (IV infusion to a plasma concentration of 2.4 +/- 0.8, 2.5 +/- 0.9, and 2.6 +/- 1.1 microg/mL at the sweating, vasoconstriction, and shivering thresholds, respectively). Each day, skin and core temperatures were increased to provoke sweating, then reduced to elicit peripheral vasoconstriction and shivering. ⋯ However, it significantly reduced the shivering threshold from 36.2 degrees +/- 0.5 degrees C to 35.7 degrees +/- 0.7 degrees C (P = 0.012). No sedation or symptoms of panic were observed on either study day. The observed reduction in the shivering threshold explains the drug's efficacy for treatment of postoperative shivering; however, a reduction of only 0.5 degrees C is unlikely to markedly facilitate induction of therapeutic hypothermia as a sole drug.
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Anesthesia and analgesia · Nov 2005
Randomized Controlled Trial Clinical TrialThe efficacy of plethysmographic pulse wave amplitude as an indicator for intravascular injection of epinephrine-containing epidural test dose in anesthetized adults.
In this study, I evaluated the efficacy of plethysmographic pulse wave amplitude (PPWA) in detecting intravascular injection of a simulated epidural test dose containing 15 microg of epinephrine in adults during either sevoflurane or isoflurane inhaled anesthesia and compared its reliability to the classical heart rate (HR; positive if > or =10 bpm) and systolic blood pressure (SBP; positive if > or =15 mm Hg) criteria. Eighty patients were randomized to receive either 1 mean alveolar anesthetic concentration of sevoflurane or 1 mean alveolar anesthetic concentration of isoflurane (n = 40 for each anesthesia group). Patients in each anesthesia group microg of epinephrine IV or 3 mL of saline IV (n = 20 each). ⋯ Using this value, the sensitivity, specificity, positive predictive, and negative predictive values of PPWA were 100% in both anesthetic groups. On the contrary, sensitivities of 85% and 95% were obtained based on HR criterion in the sevoflurane and isoflurane patients, respectively, and a sensitivity of 90% was obtained in both anesthesia groups on the basis of SBP criterion. In conclusion, PPWA is a reliable alternative to conventional hemodynamic criteria for detection of an intravascular injection of epidural test dose.
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Anesthesia and analgesia · Nov 2005
Comparative StudyA comparison of the laryngeal tube and bag-valve mask ventilation by emergency medical technicians: a feasibility study in anesthetized patients.
Airway management is of major importance in emergency care. The basic technique for all health care providers is bag-valve mask (BVM) ventilation, which requires skill and may be difficult to perform. Endotracheal intubation, which is the advanced method for securing the airway, is a demanding technique that has been shown to be associated with infrequent success, even when used by experienced paramedical personnel. ⋯ Those who inserted the LT on the first attempt (73%) required 48.2 +/- 14.7 s for the insertion. Both the LT and BVM provided adequate oxygenation and ventilation. In this study, we found that inexperienced fire-EMT students inserted LT and performed 1-min ventilation with a reasonable success rate and insertion time in anesthetized patients.