Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2004
Neither the accuracy nor the precision of thermal dilution cardiac output measurements is altered by acute tricuspid regurgitation in pigs.
Whether measurement of cardiac output using the thermal dilution technique (TDCO) is valid in the presence of tricuspid regurgitation (TR) is controversial. We assessed the accuracy and precision of the technique in pigs by comparison with data from an electromagnetic flowmeter on the aorta (EMCO). TR was created with sutures that immobilized the free-wall leaflets of the tricuspid valve, and cardiac output was adjusted with dobutamine to give values comparable to control measurements. TR reduced forward stroke volume from 17.2 to 12.6 mL/beat and caused the right atrium to dilate and pulse in synchrony with the right ventricle. Acute TR did not affect the linear regression relation between TDCO and EMCO and did not alter the correlation coefficient (r = 0.94 during both control and TR). These data demonstrate that acute TR does not affect the accuracy or precision of TDCO in pigs. ⋯ Cardiac output is a valuable measurement that guides the medical care of patients with heart and lung disease. This study demonstrates that the thermal dilution technique of determining cardiac output is valid when acute tricuspid valve regurgitation is present in pigs.
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Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Comparative Study Clinical TrialThe effects of spread of block and adrenaline on cardiac output after epidural anesthesia in young children: a randomized, double-blind, prospective study.
Epidural anesthesia is considered to be without significant hemodynamic consequence in young children. However, conversely to adults, few studies have investigated cardiac output. Using transesophageal Doppler monitoring of cardiac output, we prospectively investigated hemodynamic alterations in 48 children (median age, 22.5 mo) receiving sevoflurane general anesthesia combined with caudal or thoracolumbar epidural anesthesia. They were randomly assigned to receive 0.8 mL/kg of plain local anesthetic mixture (lidocaine 1% + bupivacaine 0.25% (50/50) + 1 microg/mL of fentanyl) or 1 mL/kg of the same mixture with 5 microg/mL of adrenaline. No significant hemodynamic alteration was elicited in caudal and thoracolumbar groups receiving the plain mixture except a moderate decrease in heart rate. Conversely, a mixture with adrenaline added provoked a significant decrease in mean arterial blood pressure by 14% and 17%, in systemic vascular resistance by 24% and 40%, and an increase in cardiac output by 20% and 34% in caudal and thoracolumbar groups, respectively. The adrenaline effect was greater by the thoracolumbar than the caudal approach. In young children, epidural anesthesia induces an increase in cardiac output only when adrenaline is added to local anesthetics, probably through its systemic absorption from the epidural space. ⋯ Epidural anesthesia may induce significant hemodynamic changes, well documented in adults. Using noninvasive hemodynamic monitoring in children, we reported an increase in cardiac output and a decrease in arterial blood pressure only when epinephrine was added to epidurally-injected local anesthetics.
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Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialPerioperative rofecoxib improves early recovery after outpatient herniorrhaphy.
Non-opioid analgesics have become increasingly popular as part of a multimodal regimen for pain management in the ambulatory setting. We designed this randomized, double-blind, placebo-controlled study to evaluate the effect of perioperative administration of the cyclooxygenase-2 inhibitor rofecoxib on patient outcome after inguinal herniorrhaphy procedures. Sixty consenting outpatients undergoing elective hernia repair surgery were randomly assigned to one of two treatment groups: control (vitamin C, 500 mg) or rofecoxib (rofecoxib, 50 mg). The first oral dose of the study medication was administered 30-40 min before entering the operating room, and a second dose of the same medication was given on the morning of the first postoperative day. Recovery times, postoperative pain scores, the need for "rescue" analgesics, and side effects were recorded at 1- to 10-min intervals before discharge from the recovery room. Follow-up evaluations were performed at 36 h, 7 days, and 14 days after surgery to assess postdischarge pain, analgesic requirements, resumption of normal activities, as well as patient satisfaction with their postoperative pain management. Rofecoxib significantly decreased the early recovery times, leading to an earlier discharge home after surgery (88 +/- 30 vs 126 +/- 44 min, P < 0.05). When compared with the control group, the patients' median [range] quality of recovery score was also significantly higher in the rofecoxib group (18 [14-18] vs 16 [13-18], P < 0.05). In the predischarge period, a significantly larger percentage of patients required rescue pain medications in the control group (67% vs 37% in the rofecoxib group, P < 0.05). At the 36-h follow-up assessment, rofecoxib-treated patients reported significantly reduced oral analgesic requirements (0 [0-20] vs 9 [1-33] pills, P < 0.05) and lower maximal pain scores, resulting in improved patient satisfaction with their postoperative pain management (3 [1-4] vs 2 [0-3], P < 0.05). However, there were no differences in the times required to resume their activities of daily living. In conclusion, perioperative rofecoxib, 50 mg per os, significantly decreased postoperative pain and the need for analgesic rescue medication, leading to a faster and improved quality of recovery after outpatient hernia surgery. However, perioperative use of rofecoxib failed to improve recovery end points in the postdischarge period. ⋯ Rofecoxib (50 mg per os), given before and after surgery, was effective in improving postoperative pain management, as well as the speed and quality of recovery after outpatient inguinal herniorrhaphy. However, it failed to accelerate the postdischarge resumption of normal activities of daily living.
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Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialEpidural infusions of ropivacaine and bupivacaine for labor analgesia: a randomized, double-blind study of obstetric outcome.
Studies have shown better obstetric outcome when ropivacaine 0.25% was used for labor epidural analgesia compared with bupivacaine 0.25%, but it is controversial whether there is any difference at smaller concentrations. In a prospective, double-blind trial, we randomized 350 ASA physical status I and II parturients with term cephalic singleton pregnancies to receive epidural labor analgesia using ropivacaine or bupivacaine. Analgesia was initiated with a 0.25% solution and maintained with a continuous infusion of a 0.1% solution with fentanyl 0.0002%. Supplementary boluses of 0.25% solution were given when requested. Labor was managed according to institutional standard labor ward protocols. Among patients who delivered vaginally, the duration of the first stage of labor was shorter in the ropivacaine group (median, 520 min; interquartile range, 377-745 min) compared with the bupivacaine group (645 min; interquartile range, 460-820 min; P = 0.009), but there was no difference in any other obstetric or neonatal outcomes. The mode of delivery was similar between groups, with operative (instrumental vaginal and cesarean) delivery rates of 61.8% (95% confidence interval, 54.4%-68.8%) in the ropivacaine group and 58.4% (95% confidence interval, 50.9%-65.5%) in the bupivacaine group (P = 0.72). ⋯ In a randomized-controlled study, we found no major outcome advantage of continuous epidural infusion of ropivacaine 0.1% with fentanyl 0.0002% over bupivacaine 0.1% with fentanyl 0.0002% for labor analgesia. Although ropivacaine was associated with a shorter first stage of labor, the relative difference is probably of limited clinical importance, and there was no difference in the mode of delivery.