Anesthesia and analgesia
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Anesthesia and analgesia · May 2001
Randomized Controlled Trial Clinical TrialThe safety and efficacy of sevoflurane anesthesia in infants and children with congenital heart disease.
We tested the hypothesis that sevoflurane is a safer and more effective anesthetic than halothane during the induction and maintenance of anesthesia for infants and children with congenital heart disease undergoing cardiac surgery. With a background of fentanyl (5 microg/kg bolus, then 5 microg. kg(-1). h(-1)), the two inhaled anesthetics were directly compared in a randomized, double-blinded, open-label study involving 180 infants and children. Primary outcome variables included severe hypotension, bradycardia, and oxygen desaturation, defined as a 30% decrease in the resting mean arterial blood pressure or heart rate, or a 20% decrease in the resting arterial oxygen saturation, for at least 30 s. There were no differences in the incidence of these variables; however, patients receiving halothane experienced twice as many episodes of severe hypotension as those who received sevoflurane (P = 0.03). These recurrences of hypotension occurred despite an increased incidence of vasopressor use in the halothane-treated patients than in the sevoflurane-treated patients. Multivariate stepwise logistic regression demonstrated that patients less than 1 yr old were at increased risk for hypotension compared with older children (P = 0.0004), and patients with preoperative cyanosis were at increased risk for developing severe desaturation (P = 0.049). Sevoflurane may have hemodynamic advantages over halothane in infants and children with congenital heart disease. ⋯ In infants and children with congenital heart disease, anesthesia with sevoflurane may result in fewer episodes of severe hypotension and less emergent drug use than anesthesia with halothane.
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Anesthesia and analgesia · May 2001
Randomized Controlled Trial Clinical TrialSmall-dose S(+)-ketamine reduces postoperative pain when applied with ropivacaine in epidural anesthesia for total knee arthroplasty.
Reduction of nociceptive input through blockade of N-methyl-D-aspartate (NMDA) receptors has been reported. We compared the effects of epidural S(+)-ketamine versus placebo on postoperative pain in a randomized, double-blinded study in 37 patients undergoing unilateral knee arthroplasty. After lumbar epidural anesthesia with ropivacaine (10 mg/mL, 10-20 mL), 19 patients received 0.9% epidural saline, and 18 patients received 0.25 mg/kg epidural S(+)-ketamine 10 min before surgical incision. After surgery, patient-controlled epidural analgesia with ropivacaine was provided. During the first 8 h after surgery, visual analog scale pain rating was similar between groups. Twenty-four and 48 h after surgery, patients anesthetized with ropivacaine had higher visual analog scale ratings at rest and during movement (P < 0.05) than patients anesthetized with S(+)-ketamine and ropivacaine. Forty-eight hours after surgery, patients anesthetized with ropivacaine also consumed more ropivacaine (558 +/- 210 mg) (P < 0.01) than those anesthetized with S(+)-ketamine and ropivacaine (319 +/- 204 mg). Adverse events were similar between groups. Patients who received S(+)-ketamine and ropivacaine rated the quality of their pain therapy better than those who received ropivacaine alone (P < 0.05). We conclude that the combination of S(+)-ketamine and ropivacaine in epidural anesthesia increases postoperative pain relief when compared with ropivacaine. ⋯ Epidural S(+)-ketamine applied with ropivacaine before surgery is a rational approach to decrease injury-induced pain sensitization. Epidural blockade with an N-methyl-D-aspartate receptor antagonist and a local anesthetic may provide better analgesia in the postoperative period than a local anesthetic alone.
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Anesthesia and analgesia · May 2001
Randomized Controlled Trial Clinical TrialThe effect of intranasal fentanyl on the emergence characteristics after sevoflurane anesthesia in children undergoing surgery for bilateral myringotomy tube placement.
Children undergoing placement of bilateral myringotomy tubes (BMT) often exhibit pain-related behavior (agitation) in the postanesthesia care unit. We compared the emergence and recovery profiles of pediatric patients who received sevoflurane with or without supplementary intranasal fentanyl for BMT surgery. By using a prospective, double-blinded design, 150 children 6 mo to 5 yr of age, scheduled for routine BMT surgery, were anesthetized with sevoflurane (2%-3%) in a 60% N(2)O/O(2) gas mixture. Patients were randomized to receive equal volumes of intranasal saline (Control), 1 microg/kg fentanyl or 2 microg/kg fentanyl. A blinded observer evaluated each patient using a previously described 4-point agitation scale and the Steward recovery scale. Response to parental presence was observed after a score of six (full recovery) was achieved on the Steward recovery scale. There were no significant differences among the three groups regarding age, weight, surgeon, duration of anesthesia, or ear condition. Recovery times and emergence characteristic scores were not statistically different. Agitation scores were significantly reduced in the 2-microg/kg Fentanyl group as compared with the Control group (P = 0.012). Fentanyl 2 microg/kg is recommended to reduce the incidence of agitation seen in these patients. ⋯ We examined the use of nasally administered fentanyl for the relief of agitation or discomfort after placement of bilateral myringotomy tubes in 150 children ages 6 mo to 5 yr using a prospective, double-blinded design. Fentanyl 2 microg/kg was found to reduce the incidence of agitation in these patients.
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Anesthesia and analgesia · May 2001
Randomized Controlled Trial Clinical TrialPreoxygenation with tidal volume and deep breathing techniques: the impact of duration of breathing and fresh gas flow.
Various techniques of "preoxygenation" before anesthetic induction have been advocated, including tidal volume breathing (TVB) for 3-5 min, four deep breaths (DB) in 0.5 min, and eight DB in 1 min. However, no study has compared the effectiveness of these techniques, assessed extending deep breathing beyond 1 min, or investigated the influence of fresh gas flow (FGF) in the same subjects using a circle absorber system. In 24 healthy adult volunteers breathing oxygen from a circle absorber system by tight-fitting mask, we compared TVB/5 min and deep breathing at a rate of 4 DB/0.5 min for 2 min at 5, 7, and 10 L/min FGF. Inspired and end-tidal respiratory gases were measured at 0.5-min intervals. During TVB, end-tidal oxygen (ETO2) increased rapidly and plateaued by 2.5 min at 86%, 88%, and 88% with 5, 7 and 10 L/min FGF, respectively. ETO2 values of > or =90% were attained between 3 and 4 min. Four DB/0.5 min increased ETO2 to 75%, 77%, and 80% at 5, 7, and 10 L/min FGF. Eight DB/min resulted in ETO2 values of 82% and 87% at 7 and 10 L/min, respectively. Extending deep breathing to 1.5 and 2 min with 10 L/min FGF increased ETO2 by > or =90%, although a decrease in ETCo(2) was noted. We concluded that TVB/3-5 min was effective in achieving maximal "preoxygenation" whereas 4 DB/0.5 min resulted in submaximal "preoxygenation," and thus should be used only when time is limited. Increasing FGF from 5 to 10 L/min does not enhance "preoxygenation" with either TVB or 4 DB/0.5 min. Deep breathing yields maximal "preoxygenation" when extended to 1.5 or 2 min, and only when high (10 L/min) FGF is used. ⋯ Using a circle absorber system, normal breathing of oxygen for 3-5 min achieves optimal oxygenation of the lungs; whereas 4 deep breaths in 30 s does not. However, extending deep breathing to 1.5-2 min and using a high flow of oxygen improves oxygenation of the lungs to the same degree as normal breathing for 3-5 min. This may have important implications for patient safety.
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Anesthesia and analgesia · May 2001
Clinical Trial Controlled Clinical TrialThe analgesic efficacy of tramadol is impaired by concurrent administration of ondansetron.
Tramadol has weak opioid properties, and an analgesic effect that is mediated mainly by inhibition of the reuptake of norepinephrine and serotonin (5-hydroxytryptamine [5-HT]) and facilitation of 5-HT release (1,2) at the spinal cord. Because 5-HT3 receptors play a key role in pain transmission at the spinal level (3), the 5-HT3 antagonist ondansetron may decrease the efficacy of tramadol, as suggested in an abstract by Maroof et al. ⋯ Early postoperative pain scored differed significantly between the test groups. We therefore tested the hypothesis that the tramadol requirement by patient-controlled analgesia (PCA) may be increased when ondansetron is administered for antiemetic prophylaxis.