Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2002
The effect of chin lift, jaw thrust, and continuous positive airway pressure on the size of the glottic opening and on stridor score in anesthetized, spontaneously breathing children.
Chin lift and jaw thrust are two common maneuvers used to improve the patency of the upper airway during general anesthesia. We investigated the effect of these maneuvers combined with continuous positive airway pressure (CPAP) on the size of glottic opening and on stridor score. Forty children, aged 2--9 yr, premedicated with midazolam and spontaneously breathing end-tidal 1% halothane and equal parts of nitrous oxide and oxygen, were studied. A flexible fiberoptic bronchoscope was placed via mask and one nostril to the level of the junction of the soft palate and oropharynx. Video recordings and simultaneous stridor scores were obtained during six conditions: 1) chin unsupported, 2) manual chin lift, 3) chin lift and CPAP 10 cm H(2)O, 4) repeat chin unsupported, 5) manual jaw thrust, and 6) jaw thrust and CPAP 10 cm H(2)O. Videos were analyzed to determine the percentage of glottic opening (POGO) score. POGO score increased (P < 0.05) in Conditions 2, 3, 5, and 6. With increasing POGO score there was a decrease in stridor score (P < 0.05). ⋯ Chin lift and jaw thrust maneuvers combined with continuous positive airway pressure improve the view of the glottic opening as viewed by flexible nasal laryngoscopy and decrease stridor in anesthetized, spontaneously breathing children.
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Anesthesia and analgesia · Mar 2002
Randomized Controlled Trial Comparative Study Clinical TrialTramadol infusion for postthoracotomy pain relief: a placebo-controlled comparison with epidural morphine.
We compared continuous IV tramadol as an alternative to neuraxial or systemic opioids for the management of postthoracotomy pain in a prospective, randomized, double-blinded, controlled study. General anesthesia was supplemented by thoracic epidural analgesia with 0.25% bupivacaine. At rib approximation, patients received one of the following: IV tramadol (150-mg bolus followed by infusion, total 450 mg/24 h, n = 29), epidural morphine (2 mg, then 0.2 mg/h, n = 30), or patient-controlled analgesia (PCA) morphine only (n = 30). All patients received PCA morphine and rescue morphine as necessary postoperatively. For the first 24 h, pain and sedation scores and respiratory, cardiovascular, and side effect measures were monitored. There was no significant difference in pain scores and PCA morphine use between tramadol and epidural morphine. Pain scores at rest and on coughing were lower in the Tramadol and Epidural Morphine groups than in the PCA Morphine group at various time points over the first 12 h. The Tramadol and Epidural Morphine groups used significantly less hourly PCA morphine than the PCA Morphine group at specific time points in the first 10 h. Vital capacities in the Tramadol group were significantly closer to baseline values at the 20-h point than in the PCA Morphine group. We conclude that an intraoperative bolus of tramadol followed by an infusion was as effective as epidural morphine and avoided the necessity of placing a thoracic epidural catheter. ⋯ A prospective, randomized, double-blinded, placebo-controlled study of postthoracotomy pain relief showed that IV tramadol in the form of a bolus followed by continuous infusion was as effective as epidural morphine. The use of tramadol avoids the necessity of placing a thoracic epidural catheter.
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Anesthesia and analgesia · Mar 2002
Randomized Controlled Trial Clinical TrialThe primary action of epidural fentanyl after cesarean delivery is via a spinal mechanism.
We tested the hypotheses that the primary mechanism of action of epidural fentanyl after cesarean delivery is spinal and that very small dose epidural bupivacaine with epinephrine enhances this effect. After elective cesarean delivery, 100 parturients were randomized in a double-blinded design to four groups. Group I and II patients received a continuous 12 mL/h epidural infusion of bupivacaine 0.015% with epinephrine 1 microg/mL for 48 h and Groups III and IV received a 12 mL/h saline epidural infusion instead. Fentanyl 20 microg/mL was administered via a patient-controlled analgesia device either into the epidural infusion (Groups I and IV) or IV (Groups II and III). When compared to patients receiving epidural fentanyl, those receiving IV fentanyl required larger mean infused and total dose of fentanyl (P < 0.0001), reported more pain (P < 0.001), and had a more frequent incidence of excessive sedation (P < 0.01), nausea (P < 0.01), and vomiting (P < 0.01). Plasma concentrations of fentanyl were larger for Group II and III than for Groups I and IV (P < 0.001) at 24 and 48 h. Our results support the hypothesis that the primary mechanism of analgesia of epidural fentanyl after cesarean delivery is spinal. Our data also show that the total required dose of epidural, but not IV, fentanyl is reduced by very small dose epidural bupivacaine and epinephrine (Group I versus Group IV, P < 0.02 and Group II vs Group III, not significant). ⋯ Fentanyl administered epidurally to parturients after cesarean delivery has a primarily spinal mechanism of action and this effect is enhanced by very small dose epidural bupivacaine and epinephrine.
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Anesthesia and analgesia · Mar 2002
Randomized Controlled Trial Clinical TrialThe effects of urapidil on thermoregulatory thresholds in volunteers.
In a previous study we have shown that the antihypertensive drug, urapidil, stops postanesthetic shivering. One possible mechanism in the inhibition of postanesthetic shivering by urapidil may be alterations in thermoregulatory thresholds. We therefore studied the effects of urapidil on vasoconstriction and shivering thresholds during cold-induced shivering in volunteers. Seven healthy male volunteers were cooled by an infusion of saline at 4 degrees C on two study days separated by 48 h. Thermoregulatory vasoconstriction was estimated using forearm minus fingertip skin-temperature gradients, and values exceeding 0 degrees C were considered to represent significant vasoconstriction. The rectal core temperatures at the beginning of shivering and at vasoconstriction were considered the thermoregulatory thresholds. Before cooling, either 25 mg of urapidil or placebo was administered randomly and blindly to each volunteer. When shivering occurred continuously for 10 min, another 25 mg of urapidil was administered IV to completely stop shivering. Urapidil led to a decrease in core temperature at vasoconstriction and shivering threshold by 0.4 degrees C plus/minus 0.2 degrees C (P < 0.001) and 0.5 degrees C plus/minus 0.3 degrees C (P < 0.01), respectively. Oxygen consumption increased during shivering by 70% plus/minus 30% (P < 0.01) in comparison with baseline and decreased levels after shivering stopped, despite the continued low core temperature. Our investigation shows that urapidil stops postanesthetic shivering by decreasing important thermoregulatory thresholds. This means that shivering, not hypothermia, is treated, and hypothermia will need more attention in the postanesthesia care unit. ⋯ In this study we show that the antihypertensive drug urapidil stops cold-induced shivering and decreases normal thermoregulatory responses, i.e., the thresholds for vasoconstriction and shivering, in awake volunteers.
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Anesthesia and analgesia · Mar 2002
Randomized Controlled Trial Comparative Study Clinical TrialSpinal ropivacaine for cesarean delivery: a comparison of hyperbaric and plain solutions.
We compared, in this prospective, randomized, double-blinded study, the characteristics of spinal anesthesia with plain and hyperbaric ropivacaine for elective cesarean delivery. We hypothesized that the addition of glucose would change the onset, offset, and extent of motor and sensory block from intrathecal ropivacaine. Forty ASA physical status I--II women were given 25 mg of either ropivacaine (n = 20) or ropivacaine in 8.3% glucose (n = 20) intrathecally, via a combined spinal/epidural technique in the right lateral position. Sensory changes to ice and pinprick and motor block (Bromage score) were recorded at 2.5-min intervals. Adequate anesthesia for surgery was achieved in all patients in the Hyperbaric group, whereas in the Plain group, five (25%) patients required epidural top-up because of insufficient rostral spread (P < 0.05). With hyperbaric ropivacaine, we found the following: higher cephalic spread (median [range] maximum block height to pinprick, T1 [T4 to C2] versus T3 [T11 to C3], P < 0.001); lower coefficient of variation of maximum block height (17.7% vs 21.9%); faster onset to T4 dermatome (mean [SD] 7.7 [4.9] vs 16.4 [14.1] min, P = 0.015); and faster recovery to L1 (189.0 [29.6] vs 215.5 [27.0] min, P = 0.01). The onset of complete motor block (9.9 [5.3] vs 13.8 [5.4] min, P = 0.027) and complete recovery (144.8 [28.4] vs 218.5 [56.8] min, P < 0.001) was also faster. No neurologic symptoms were found at 24 h. ⋯ We compared hyperbaric and plain ropivacaine for combined spinal/epidural analgesia in the lateral position in patients undergoing elective cesarean delivery. Hyperbaric ropivacaine produced more rapid block with faster recovery and less requirement for epidural supplementation compared with plain ropivacaine.