Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Clinical TrialThe effects of desmopressin and 6% hydroxyethyl starch on factor VIII:C.
In moderate doses of 20 mL/kg (1.2 g/kg), hydroxyethyl starch (HES) 6% decreases factor VIII:C activity. Desmopressin (DDAVP) increases circulating levels of factor VIII:C by stimulating the release of factor VIII:C from peripheral storage sites. The objective of this study was to monitor the changes in factor VIII:C associated with sequential HES and DDAVP administration. ⋯ After HES administration, factor VIII:C levels decreased significantly, to 69% of baseline, in both groups. After study drug administration, factor VIII:C in Group 1 increased significantly to 135% of baseline at 30 min and 115% of baseline at 60 min while in Group 2 average factor VIII:C levels remained below baseline at 30 and 60 min. DDAVP produced an increase in factor VIII:C activity despite HES administration and should be considered a treatment option for the mild coagulopathy infrequently associated with HES administration.
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Clinical TrialAxillary brachial plexus anesthesia: electrical versus cold saline stimulation.
The aim of this study was to investigate which of two methods of nerve stimulation, cold saline-induced paresthesia or use of a nerve stimulator, was more effective in increasing the successful brachial plexus block rate by the axillary approach. Twenty patients were randomly assigned to Group A (saline below 11 degrees C), and 20 patients to Group B (nerve stimulator). All blocks were performed by the same anesthesiologist using 40 mL of 1.5% mepivacaine and 4 mL of 8.4% sodium bicarbonate. ⋯ A motor response was evoked by a nerve stimulator in 17 patients (85%). Two patients (10%) had a paresthesia in the hand without a motor response with the current at less than 1 mA. A successful block was achieved in 19 patients in each group.
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Anesthesia and analgesia · Oct 1996
ReviewPostoperative epidural opioid analgesia: what are the choices?
The administration of hydrophilic opioids via a continuous infusion results in selective spinal analgesia with a low incidence of side effects. Lipophilic opioids may also be associated with spinal effects. However, the doses required to produce postoperative analgesia also produce plasma concentrations within the MEAC. ⋯ Regardless of the mechanism of action, epidural administration of lipophilic opioids may offer no clinical advantages over the IV route. Notwithstanding, epidural administration of small doses of lipophilic opioids in combination with local anesthetics may offer significant clinical advantages over systemic administration of opioids alone. Dose-ranging studies will be necessary to determine the ideal concentrations of opioids and local anesthetics, as well as the ratios of the two drugs to obtain optimal analgesia with minimal incidence of side effects.
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The Sellick maneuver or cricoid pressure is an effective means of preventing passive aspiration of gastric contents. Recent studies recommend a pressure of 20 newtons (N) when the patient is awake, increasing to 30-40 N with unconsciousness. This study was proposed to determine whether with education and practice, anesthesia providers and assistants could be taught a recommended cricoid pressure and retain this skill. ⋯ Initial attempts revealed inadequate force by all participants, "awake" and "anesthetized". All participants were able to learn the recommended amount of applied pressure and were able to retain this knowledge after 3 mo. This model represents an easy and practical means of teaching the application of the optimal level of force to practitioners and assistants.
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Anesthesia and analgesia · Oct 1996
Comparative StudyA comparison of the local anesthetic effects of meperidine, fentanyl, and sufentanil on dorsal root axons.
The local anesthetic effects of opioids have been demonstrated in both clinical and laboratory studies. Clinically, both meperidine and sufentanil can produce segmental sensory anesthesia. However, previous studies of the effects of opioids on nerve conduction have all made use of peripheral nerve preparations and yielded conflicting results. ⋯ Fentanyl (0.6 microM and 3 microM) and sufentanil (1.04 microM) failed to affect the nerve conduction in any dorsal root axon. The discrepancy between laboratory and clinical observations is discussed. We suggest that the site of conduction block may occur at the proximal end of the dorsal root as it passes through the dorsal root entry zone, an anatomically unique segment of the primary sensory pathway with decreased conduction safety for action potential propagation.