Anesthesiology
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Comparative Study
Comparison of equipressor doses of norepinephrine, epinephrine, and phenylephrine on septic myocardial dysfunction.
Myocardial depression is a frequent event during septic shock and may mimic a cardiogenic shock state with decreased cardiac output. Nevertheless, data are scarce regarding the myocardial effects of vasopressors used to treat hypotension. In this study, the authors compared the effects of three commonly used vasopressors acting on different adrenergic receptors on myocardial function in a rodent model of septic shock, as explored with conductance catheter and positron emission tomography. ⋯ Phenylephrine, a drug without β-1 effects, was associated with decreased ventricular performance and ventriculoarterial uncoupling, whereas epinephrine and norepinephrine improved global hemodynamics and myocardial function in severely hypokinetic and hypotensive experimental septic shock. Nevertheless, epinephrine was associated with increased myocardial oxygen consumption. Thus, norepinephrine appears to be a more reliable and safer strategy as a first-line therapy in this particular setting.
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Randomized Controlled Trial
Cerebral oxygen saturation measured by near-infrared spectroscopy and jugular venous bulb oxygen saturation during arthroscopic shoulder surgery in beach chair position under sevoflurane-nitrous oxide or propofol-remifentanil anesthesia.
We examined the effects of different anesthetics on cerebral oxygenation and systemic hemodynamics in patients undergoing surgery in beach chair position (BCP). Jugular venous bulb oxygen saturation (SjvO2) and regional cerebral tissue oxygen saturation (SctO2) were determined while patients were placed from the supine to BCP. Whether SctO2 and SjvO2 are interchangeable in assessing the cerebral oxygenation was also examined. ⋯ The margin of safety against impaired cerebral oxygenation is greater and SjvO2 is more preserved with S/N than with P/R anesthesia. SctO2 may not be reliable in detecting a low SjvO2 during the surgery in BCP.
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Gabapentin is most commonly prescribed for chronic pain, but acute perioperative effects, including preemptive analgesia and hemodynamic stabilization, have been reported. Adrenal chromaffin cells are a widely used model to investigate neurosecretion, and adrenal catecholamines play important physiologic roles and contribute to the acute stress response. However, the effects of gabapentin on adrenal catecholamine release have never been tested. ⋯ The authors show Ca2+ entry was not inhibited by gabapentin but was less effective at triggering vesicle fusion. The work also demonstrates that chromaffin cells are a useful model for additional investigation of the cellular mechanism(s) by which gabapentin controls neurosecretion. In addition, it identifies altered adrenal catecholamine release as a potential contributor to some of the beneficial perioperative effects of gabapentin.