Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2006
Comparative StudyKetamine attenuates sympathetic activity through mechanisms not mediated by N-methyl-D-aspartate receptors in the isolated spinal cord of neonatal rats.
Ketamine is believed to have sympathomimetic effects, although the central mechanism remains unclear. Using an in vitro splanchnic nerve-spinal cord preparation from neonatal rats, our previous investigations have demonstrated that tonic sympathetic activity is spontaneously generated from the thoracic spinal cord. We designed this study to investigate whether applications of ketamine to the cord would augment sympathetic activity and whether this action was dependent on N-methyl-d-aspartate receptors. ⋯ The 50% inhibitory concentration of ketamine on sympathetic activity was 32 muM. Pretreatment with DL-2-amino-5-phosphonovaleric acid, a selective competitive N-methyl-d-aspartate receptor antagonist, did not alter ketamine-induced depression of sympathetic activity. These results suggest that ketamine reduces sympathetic activity by mechanisms that are independent of N-methyl-d-aspartate receptor activity.
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Anesthesia and analgesia · Mar 2006
Randomized Controlled Trial Comparative StudyUpper airway collapsibility in anesthetized children.
We sought to establish the feasibility of measuring upper airway narrowing in spontaneously breathing, anesthetized children using dynamic application of negative airway pressure. A secondary aim was to compare differences in upper airway collapsibility after the administration of sevoflurane or halothane. Subjects were randomized to either drug for inhaled anesthetic induction. ⋯ Pcrit for sevoflurane ranged from -6.7 to -11.6 (mean +/- sd, -9.8 +/- 1.9) cm H2O. Pcrit for halothane ranged from -8.1 to -33 (mean +/- sd, -19.4 +/- 9.3) cm H2O (sevoflurane versus halothane, P = 0.048). We conclude that when using dynamic application of negative airway pressure, halothane appears to cause less upper airway obstruction than sevoflurane at equipotent concentrations.
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Anesthesia and analgesia · Mar 2006
Comparative StudyChromosomal substitution-dependent differences in cardiovascular responses to sodium pentobarbital.
In this study we addressed initial laboratory observations of enhanced cardiovascular sensitivity to sodium pentobarbital (PTB) in normotensive Dahl Salt Sensitive rats (SS) compared to Brown Norway (BN) rats. We also used unique consomic (chromosomal substitution) strains to confirm preliminary observations that such differences were related to chromosome 13. Increasing concentrations of PTB were administered sequentially to SS, BN, and SS strains with BN chromosomal substitutions until the point of cardiovascular collapse. ⋯ In neurally intact preparations, large dose PTB-induced VSM hyperpolarization was 4-5 times greater than the small dose in SS and SS.16BN but not in BN and SS.13BN strains. Denervation eliminated this strain difference. These results suggest that enhanced cardiovascular sensitivity to PTB in SS rats is related to greater hyperpolarization of VSM transmembrane potential in resistance vessels and this effect is associated with chromosome 13.
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Anesthesia and analgesia · Mar 2006
Case ReportsIntrathecal catheter granuloma associated with isolated baclofen infusion.
Intrathecal (IT) baclofen is an effective management strategy for controlling spasticity in patients unresponsive to maximal oral therapy. We present the case of a 57-yr-old woman who was rendered quadriplegic after a complete spinal cord transection at the C6 level. Her course was complicated by severe spasms, which were uncontrolled despite titrating orally administered baclofen to 80 mg/d. ⋯ These investigations revealed neither catheter displacement nor fracture as suspected but, rather, displayed the presence of a catheter tip-associated mass. Catheter tip granuloma has not previously been described in a patient receiving IT baclofen alone. This suggests that although uncommon, the possibility of catheter-associated granuloma must be considered in all patients receiving IT baclofen presenting with altered neurological function or significant increase in drug requirement.
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Anesthesia and analgesia · Mar 2006
Comparative StudyResidents' and program directors' attitudes toward research during anesthesiology training: a Canadian perspective.
We assessed the attitudes of residents and program directors (PD) toward research training in Canadian anesthesiology residency programs. Questionnaires were sent to all 476 anesthesiology residents in Canada and a modified questionnaire was sent to the PD of each of the 16 anesthesiology programs between November 2003 and April 2004. There was a 60% response rate to the resident questionnaire and 95% from the PDs. ⋯ Residents regard the time needed to learn clinical anesthesia, schedule conflicts, inadequate faculty support, and a lack of protected research time as the top barriers to undertaking a research project. PDs do not consider schedule conflicts or a lack of time as important barriers for resident research. Seventy-five percent of residents would prefer to do another academic activity, such as learning transesophageal echocardiography or taking postgraduate programs in education, rather than completing a research project during their residency.