Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2004
Randomized Controlled Trial Clinical TrialPreoperative rofecoxib oral suspension as an analgesic adjunct after lower abdominal surgery: the effects on effort-dependent pain and pulmonary function.
Rofecoxib is a selective cyclooxygenase-2 inhibitor that reduces pain and inflammation without inhibiting platelet function. We examined its effects on effort-dependent pain, postoperative morphine requirements, and pulmonary function in 48 patients recovering from open abdominal surgery. Spirometric measurement of forced expiratory volume(1) and vital capacity (FVC) were assessed preoperatively. One hour before the induction of a standardized general anesthetic, patients were given either placebo oral suspension (Group A), or rofecoxib oral suspension (25 mg [Group B] or 50 mg [Group C]) in a double-blinded manner. Postoperative pain control was provided with IV morphine in the postanesthesia care unit and IV-patient-controlled analgesia morphine on the patient care unit. Morphine dose, pain intensity at rest, and pain after respiratory effort (postoperative spirometry) were assessed at 12 and 24 h after study drug administration. The patient-controlled analgesia morphine dose at 24 h was reduced 44% in Group B (30.3 +/- 17.5 mg) and 59% in Group C (22.1 +/- 16.5 mg) versus Group A (53.7 +/- 31.1 mg); P < 0.01 (A versus B). At 12 h, pain scores at rest and after spirometry were lower in Groups B and C than in A (P < 0.05). At 24 h, resting pain scores were lowest in Group C (P < 0.05). Twelve-hour FVC was best preserved in Group C (P < 0.03). There were no inter-group differences in adverse effects or perioperative blood loss. Rofecoxib oral suspension provided a morphine-sparing effect, as well as improvements in pain control and 12-h FVC in patients recovering from open abdominal surgery. ⋯ Rofecoxib belongs to class of analgesics known as cyclooxygenase-2 inhibitors that reduce pain and inflammation with less risk of bleeding than standard nonsteroidal antiinflammatory drugs. We found that patients treated with rofecoxib 25 or 50 mg before open abdominal surgery required less IV morphine during the first day of recovery. Despite reductions in morphine requirements, rofecoxib-treated patients reported lower pain intensity scores at rest and after a vigorous cough. In the 50-mg group, improvements in pain control correlated with greater preservation of baseline cough effectiveness (vital capacity) at 12 h. These findings may offer clinical advantages in patients with preexisting pulmonary disease.
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Anesthesia and analgesia · Jan 2004
Randomized Controlled Trial Clinical TrialSingle-dose dexmedetomidine reduces agitation after sevoflurane anesthesia in children.
Emergence agitation is a common side effect of sevoflurane anesthesia in children. Dexmedetomidine, because of its sedative and analgesic properties, might be useful for the management of this adverse effect. We studied the effect of dexmedetomidine on recovery characteristics in 90 children aged 1 to 10 yr scheduled to undergo superficial lower abdominal and genital surgery. After inhaled induction with sevoflurane, patients were randomly assigned to receive saline (Group 1, n = 30), dexmedetomidine 0.15 micro g/kg (Group 2, n = 30), or dexmedetomidine 0.30 micro g/kg (Group 3, n = 30). After a laryngeal mask airway insertion a caudal block was performed in all patients. Maintenance of anesthesia was with 1% end-tidal sevoflurane and 50% nitrous oxide and spontaneous ventilation. Intraoperative hemodynamic and respiratory variables were recorded every 5 min. At the end of anesthesia time to eyes opening (TEO) and characteristics of emergence were recorded. General and intraoperative variables were similar in the 3 groups. The TEO was 7.5 +/- 5.0 min in Group 1, 8.2 +/- 5.0 min in Group 2, and 9.8 +/- 4.0 min in Group 3 (NS). The incidence (95% confidence interval) of agitation was 37% (20%-54%) in Group 1, 17% (4%-30%) in Group 2, and 10% (0%-21%) in Group 3 (P < 0.05). Paired comparisons showed a significant difference for Group 1 versus Group 3 (P < 0.05, 95% confidence interval of the difference: 7%-47%). The time to discharge from the postanesthesia care unit was similar for the 3 groups. We conclude that a dose of dexmedetomidine 0.3 micro g/kg administered after induction of anesthesia reduces the postsevoflurane agitation in children and with no adverse effects. ⋯ In children undergoing surgery using sevoflurane anesthesia, dexmedetomidine 0.3 micro g/kg administered in 10 min after induction reduced the incidence of emergence agitation from 37% in the control group to 10%. No adverse effects attributable to dexmedetomidine were observed.
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Anesthesia and analgesia · Jan 2004
Randomized Controlled Trial Clinical TrialAdministration of 100% oxygen before removal of the laryngeal mask airway does not affect postanesthetic arterial partial pressure of oxygen.
Breathing 100% oxygen at the end of general anesthesia has been shown to worsen postoperative pulmonary gas exchange when an endotracheal tube is used. Counter measures, such as high positive end-expiratory pressure or the vital-capacity maneuver, may limit this effect. Such strategies, however, may be impracticable, or even contraindicated, when the laryngeal mask airway (LMA) is used. Because of the vast differences in design between the LMA and endotracheal tube, we examined postanesthetic blood gas tensions in patients after emergence from anesthesia breathing oxygen via LMA. Sixty-four ASA physical status I-II patients undergoing general anesthesia for 60 min with LMA were randomly assigned to receive either 100% or 30% oxygen during emergence from anesthesia and removal of LMA. Postoperative blood gas measurements were taken at 30 and 60 min after removal of the LMA. At either measurement, patients treated with 100% oxygen essentially had the same arterial partial pressure of oxygen (60-min measurement: 83 +/- 8 versus 85 +/- 7 mm Hg [mean +/- SD], P = 0.14) as those treated with 30% oxygen. We conclude that breathing 100% oxygen at the end of general anesthesia does not worsen postoperative pulmonary gas exchange when an LMA is used. ⋯ The endotracheal tube and laryngeal mask airway are substantially different artificial airways used to ventilate the lungs of anesthetized patients. Breathing 100% oxygen before removing the endotracheal tube results in lung function defects. This study shows that oxygen breathing before removing the laryngeal mask airway has no effect on pulmonary function.
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Anesthesia and analgesia · Jan 2004
Clinical Trial Controlled Clinical TrialClonidine prolongs spinal anesthesia in newborns: a prospective dose-ranging study.
Spinal anesthesia may reduce the incidence of morbidity that follows general anesthesia in neonates and in former preterm infants. However, bupivacaine alone provides a block too short for complete surgery in up to 40% of the patients. Clonidine lengthens spinal anesthesia in adults and caudal block in children without significant side effects. We conducted a controlled, prospective, dose-ranging study of clonidine in spinal anesthesia in 75 neonates, including 50% of former preterm infants, undergoing elective inguinal herniorrhaphy. Patients were given a spinal anesthetic with either 0.5% plain isobaric bupivacaine (1 mg/kg), or bupivacaine plus 0.25, 0.5, 1, or 2 micro g/kg clonidine. Mean arterial blood pressure, heart rate, SpO(2), sensory block extension and duration were the main data recorded. Mean arterial blood pressure, heart rate, SpO(2), and block extension were similar in the five groups. Duration of spinal block increased from 67 (58-82) min in the control group up to 111 (93-125) min in the group receiving 1 micro g/kg clonidine (P < 0.003). Transient hypotension occurred more often (P < 0.05), and caffeine was given more often, when 2 micro g/kg clonidine was given. We conclude that 1 micro g/kg clonidine provides a significant improvement in spinal anesthesia duration in newborns without significant side effects. ⋯ Spinal anesthesia is suitable but often too short for complete surgery in newborns. This controlled, randomized, prospective, dose-ranging study was conducted in 75 neonates to test the hypothesis that clonidine could significantly lengthen bupivacaine spinal block. Clonidine 1 micro g/kg, added to spinal isobaric bupivacaine, doubles the duration of the block without significant deleterious hemodynamic or respiratory side effects.
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Anesthesia and analgesia · Jan 2004
ReviewAre peripheral opioid antagonists the solution to opioid side effects?
Opioid medication is the mainstay of therapy for severe acute and chronic pain. Unfortunately, the side effects of these medications can affect patient comfort and safety, thus limiting their proven therapeutic potential. Whereas the main analgesic effects of opioids are centrally mediated, many of the common side effects are mediated via peripheral receptors. Novel peripheral opioid antagonists have been recently introduced that can block the peripheral actions of opioids without affecting centrally mediated analgesia. We review the clinical and experimental evidence of their efficacy in ameliorating opioid side effects and consider what further information might be useful in defining their role. ⋯ The major analgesic effects of opioid medication are mediated within the brain and spinal cord. Many of the side effects of opioids are caused by activation of receptors outside these areas. Recently developed peripherally restricted opioid antagonists have the ability to block many opioid side effects without affecting analgesia.