Anesthesiology
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Randomized Controlled Trial Clinical Trial
Peripheral analgesic effects of ketamine in acute inflammatory pain.
BACKGROUND. This study examined the analgesic effect of local ketamine infiltration, compared with placebo and systemic ketamine, in a human model of inflammatory pain. ⋯ Ketamine infiltration had brief local analgesic effects, but several measures of pain and hyperalgesia were unaffected. Therefore, a clinically relevant effect of peripheral ketamine in acute pain seems unlikely.
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Randomized Controlled Trial Clinical Trial
A comparison of the respiratory effects of sevoflurane and halothane in infants and young children.
This study compared the respiratory effects of sevoflurane with those of halothane in anesthetized infants and young children. ⋯ Minute ventilation and respiratory frequency were lower in infants during 1 MAC sevoflurane in nitrous oxide than during halothane anesthesia. However, these differences may not be clinically relevant at these concentrations, given the modest increase in PETCO2. Differences in parameters of breath timing and shape between sevoflurane and halothane suggest different effects of these anesthetic agents on ventilatory control.
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Randomized Controlled Trial Clinical Trial
Intrathecal sufentanil produces sensory changes without hypotension in male volunteers.
Intrathecally administered sufentanil is frequently associated with hypotension and sensory changes in women undergoing labor. In this study, the authors examined whether intrathecally administered sufentanil has similar effects in pain-free individuals with low concentrations of progesterone (i.e., male volunteers). ⋯ Intrathecally administered sufentanil did not affect blood pressure in male volunteers. The other effects of sufentanil, however, were similar to those observed in women undergoing labor. This suggests that the hypotension occurring in these women after intrathecally administered sufentanil is secondary to relief of pain, rather than to a sympathectomy.
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Randomized Controlled Trial Clinical Trial
The impact of systemic vasoconstrictors on the cerebral circulation of anesthetized patients.
BACKGROUND. The effect of vasoconstrictors on intracerebral hemodynamics in anesthetized patients is controversial. The influence of phenylephrine and norepinephrine on the cerebral circulation was investigated in isoflurane- or propofol-anesthetized patients using transcranial Doppler ultrasonography. ⋯ The results of the present study indicate that norepinephrine and phenylephrine do not directly affect intracranial hemodynamics in anesthetized patients, but rather that hemodynamic changes observed with vasoconstrictors reflect the effect of the background anesthetic agents on cerebral pressure autoregulation.
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Comparative Study
Comparison of pH-stat and alpha-stat cardiopulmonary bypass on cerebral oxygenation and blood flow in relation to hypothermic circulatory arrest in piglets.
Deep hypothermic circulatory arrest is used in neonatal cardiac surgery. Recent work has suggested improved neurologic recovery after deep hypothermic arrest with pH-stat cardiopulmonary bypass (CPB) compared with alpha-stat CPB. This study examined cortical oxygen saturation (ScO2), cortical blood flow (CBF), and cortical physiologic recovery in relation to deep hypothermic arrest with alpha-stat or pH-stat CPB. ⋯ Cortical deoxygenation during hypothermic arrest was slower after pH-stat CPB. pH-stat bypass increased the prearrest ScO2 and arrest ScO2 half-life, to increase the cortical oxygen supply and slow cortical oxygen consumption. Improved cortical physiologic recovery after hypothermic arrest was suggested with pH-stat management.