Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2008
Comparative StudyNoninvasive cardiac output determination using applanation tonometry-derived radial artery pulse contour analysis in critically ill patients.
Conventional thermodilution cardiac output (CO) monitoring is limited mainly to intensive care units and operating rooms because it requires the use of invasive techniques. To reduce the potential for complications and to broaden the applicability of hemodynamic monitoring, noninvasive methods for CO determination are being sought. Applanation tonometry allows noninvasive CO estimation through pulse contour analysis, but the method has not been evaluated in critically ill patients. ⋯ There was no significant difference in bias between the patients who were receiving vasopressor support and those who were not (P = 0.874) or between patients with good and poor applanation tonometry pressure waveform signal quality (P = 0.071). Whereas a significant increase in the invasively determined CO was observed when a fluid bolus was administered (n = 7, P = 0.016), these changes were not reflected by the noninvasive method. We conclude that radial artery applanation tonometry is not suitable to determine CO in critically ill hemodynamically unstable patients.
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Anesthesia and analgesia · Jan 2008
Clinical TrialReal-time heart rate variability and its correlation with plasma catecholamines during laparoscopic adrenal pheochromocytoma surgery.
We studied sympathovagal activity using real-time heart rate variability (HRV) and determined its relationship with plasma catecholamines to characterize short-term cardioregulatory mechanisms during laparoscopic adrenal pheochromocytoma surgery. ⋯ This study demonstrated a strong correlation between low frequency HRV, plasma norepinephrine, arterial blood pressure, and heart rate during pheochromocytoma surgery.
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Anesthesia and analgesia · Jan 2008
The prolonged analgesic effect of epidural ropivacaine in a rat model of neuropathic pain.
In clinical practice, the analgesic effects of epidurally administered local anesthetics on chronic pain sometimes outlast the duration of drug action expected from their pharmacokinetics. To investigate the underlying mechanisms of this prolonged effect, we examined the effects of ropivacaine, a local anesthetic, on pain-related behavior in a rat model of neuropathic pain. We also analyzed changes in the expression of nerve growth factor (NGF), which is involved in plasticity of the nociceptive circuit after nerve injury. ⋯ Repetitive administration of ropivacaine into the epidural space in CCI rats exerts an analgesic effect, possibly by inducing a plastic change in the nociceptive circuit.