Anesthesia and analgesia
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Anesthesia and analgesia · May 2005
An evaluation of the effects of a standard heparin dose on thrombin inhibition during cardiopulmonary bypass in neonates.
We compared the adequacy of heparinization in neonates and older children undergoing cardiopulmonary bypass (CPB) by measuring heparin activity, thrombin formation, and thrombin activity. Ten neonates and 10 older children were administered 400 U/kg of heparin before CPB. Heparin anti-Xa activity, prothrombin fragment 1.2 (F1.2), and fibrinopeptide A (FPA) were measured at baseline, after 30 min on CPB, immediately post-CPB, and 3 and 24 h post-CPB. ⋯ Higher baseline levels of F1.2 and FPA present in neonates indicate preoperative activation of their coagulation systems as compared with older children. Although F1.2 and FPA levels initially decrease with the commencement of CPB, probably representing hemodilution, the subsequent increase in these markers indicates significantly more thrombin formation and activity during and after CPB. These results raise the concern that 400 U/kg of heparin may not adequately suppress thrombin formation and activity in neonates undergoing CPB.
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Anesthesia and analgesia · May 2005
Randomized Controlled Trial Clinical TrialPreincisional dextromethorphan combined with thoracic epidural anesthesia and analgesia improves postoperative pain and bowel function in patients undergoing colonic surgery.
Colonic surgery is associated with severe postoperative pain and postoperative ileus, which contribute to delayed hospital discharge. In previous studies, we demonstrated that IM dextromethorphan (DM) provided preemptive analgesia and improved postoperative pain. The benefit of thoracic epidural anesthesia (TEA) and postoperative epidural analgesia on postoperative pain was well demonstrated. ⋯ Statistically significant improvement of postoperative pain and bowel function was observed in the following order: DM-TEA > CPM-TEA > CPM-GA. Compared with the CPM-TEA group, the DM-TEA group averaged 1.6 points lower on first-hour pain scores, 40 min longer to first PCEA request, 15.8 mL less PCEA drug over 72 h, and 14.7 h earlier bowel function (all P < 0.01). We conclude that the combination of preincisional DM (40 mg IM), intraoperative TEA, and postoperative PCEA enhances analgesia and facilitates recovery of bowel function, suggesting possible synergistic interaction with local anesthetics and opioids.
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Anesthesia and analgesia · May 2005
Randomized Controlled Trial Clinical TrialThe concentration-dependent effects of general anesthesia on spontaneous baroreflex indices and their correlations with pharmacological gains.
Beat-to-beat assessment of spontaneously occurring fluctuations in heart rate and arterial blood pressure allows noninvasive determination of cardiovagal function, but little is known regarding the effects of general anesthesia on spontaneous baroreflex (SBR) indices. We examined (a) concentration-dependent effects of sevoflurane on SBR indices, heart rate variability (HRV), and blood pressure variability and (b) correlation and agreement between pharmacological baroreflex gains and SBR indices during sevoflurane anesthesia. Continuous electrocardiogram and invasive arterial blood pressure were monitored in nine healthy volunteers before, during, and for 3 h after sevoflurane anesthesia, during which end-tidal sevoflurane was maintained at 0.7%, 1.4%, and 2.0% in random sequences. ⋯ Spontaneous sequence indices and high- and low-frequency powers of HRV demonstrated concentration-dependent depression. Pharmacological gains and SBR indices during anesthesia generally correlated well, but Bland-Altman analysis revealed that SBR indices had limits of agreement as large as the baroreflex gain itself. These data suggest that spontaneous indices are inadequate estimates of, and are inconsistent with, the pharmacological baroreflex gain during sevoflurane anesthesia.
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Anesthesia and analgesia · May 2005
Comparative StudyA comparison of the Vasotrac with invasive arterial blood pressure monitoring in children after pediatric cardiac surgery.
The Vasotrac is a device that provides near-continuous and noninvasive arterial blood pressure monitoring and may be an alternative to direct intraarterial measurement. It has been evaluated in adult patients, but minimal information is available for pediatric patients. We evaluated agreement between measurements of arterial blood pressure and heart rate obtained from the Vasotrac versus an arterial catheter in a pediatric population. ⋯ There was excellent agreement between arterial blood pressure measurement methods. Absolute mean differences based on mixed-model regression with 95% confidence intervals were 4.0 mm Hg (3.0-5.0 mm Hg), 4.3 mm Hg (3.1-5.5 mm Hg), and 3.5 mm Hg (2.5-4.0 mm Hg) for systolic blood pressure, diastolic blood pressure, and mean blood pressure, respectively. Arterial blood pressure measurements obtained from the Vasotrac agreed well with invasive arterial monitoring in pediatric patients.