ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The ability of edrophonium and neostigmine to antagonize nondepolarizing neuromuscular blockade produced by steady-state infusions of atracurium, pancuronium, and vecuronium was studied in 71 adult patients anesthetized with nitrous oxide and halothane. Infusion rates of blocking drugs were adjusted so that single twitch depression as measured by the evoked integrated EMG of the hypothenar muscles was kept at 10% of control. Two minutes after the termination of the infusion either edrophonium (0.75 mg/kg) or neostigmine (0.05 mg/kg) was administered. Single twitch depression and train-of-four (T4/T1) fade was recorded during the recovery period. T4/T1 fade ratios observed at 20 min postreversal were 0.80 (atracurium-edrophonium); 0.76 (vecuronium-edrophonium); 0.44 (pancuronium-edrophonium); 0.95 (atracuriumneostigmine); 0.89 (vecuronium-neostigmine); and 0.68 (pancuronium- neostigmine). Under conditions of this study neostigmine produced more rapid and complete recovery than did edrophonium. Although edrophonium produced adequate antagonism of atracurium if 20–30 min were allowed to elapse, edrophonium reversal of pancuronium was rarely acceptable even at 30 min. Increasing the dose of edrophonium to 1.0 mg/kg produced single twitch values of 0.90 at 5 min postreversal but did not increase the rate of recovery of the train-of-four fade ratio. Neostigmine reversal of pancuronium, on the other hand, generally produced T4/T1 ratios of >0.70 in 20–30 min. Although the pattern of recovery seen after reversal of vecuronium was in general quite similar to that seen after atracurium, two patients in the vecuronium-edrophonium group showed delayed recovery and also failed to respond significantly to subsequent doses of neostigmine. Following steady-state infusions of vecuronium, it appears that marked patient variability in the speed of recovery can occur. Our results do not confirm other published reports that suggest that edrophonium and neostigmine may be used interchangeably.

ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The relationship of train-of-four (TOF) ratio to the depression of the first twitch (TD) was investigated in 16 patients given pancuronium in doses insufficient to eliminate the fourth response in the train. In ten patients the block was allowed to spontaneously recover (Group 1) and in six it was reversed with neostigmine (Group 2) once maximum depression of TOF ratio had occurred. Maximum depression of the first response occurred in 6.5 ± 4.3 min (mean ± SD). Maximum depression of the TOF ratio was not present until 28.0 ± 11.0 min. TOF ratio was usually still decreasing when recovery of TD had begun. However, once the TOF ratio began to recover, the recovery rates for TD and TOF ratio were similar in both the spontaneously recovering and the reversed groups. TOF ratio at complete TD recovery was 74.9 ± 15.7 and 86.2 ± 15.4% for the two groups. A kinetic analysis yielded significantly different elimination rate constants for the two effects from the “effect compartment.” These findings suggest that these two effects of pancuronium are exerted at different sites.

ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The effects of three anesthetic induction agents on somatosensory evoked potentials (SEP) were assessed in unpremedicated patients who were without neurologic abnormality of the upper extremities. SEP was assessed by stimulation of the nondominant median nerve and responses were recorded over Erbs point (N10), second cervical vertebra (N14), and the contralateral cortex (P15, N20, P23 latencies, and P15–N20 and N20–P23 amplitudes). Nine patients received thipental (4 mg/kg, iv bolus), nine patients received fentanyl (25 µg/ kg, iv bolus), and nine patients received etomidate (0.4 mg/kg, iv bolus). SEP was assessed before and after drug administration at motor threshold stimulus intensity. Thiopental increased the latency of N10, N14, and N20. The amplitudes of N10-, N14-, and scalprecorded waves were not altered by thiopental. Fentanyl increased N20 and P23 latency and decreased the amplitude of P15–N20. Etomidate increased latency of N20 and P23 without alteration of latencies of N10 or N14 and increased the amplitude of P15–N20 and N20–P23, while the amplitude of N10 was unchanged and the amplitude of N14 was decreased. It is concluded that thiopental or fentanyl causes only modest alterations in early waves of upper extremity SEP, whereas etomidate increases the amplitude of scalprecorded waves. The effect of etomidate on SEP may make diagnosis of neurologic injury more difficult because of the changing waveform.

ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The effects of epidural morphine (50 µg · kg−1) after abdominal and urologic surgery were studied in 20 children ranging in age from 2 to 15 yr and weighing between 9 and 54 kg. The onset and the duration of analgesia were 30 ± 12 min and 19.5 ± 8 h, respectively (mean ± SD). Side effects were pruritus (4/20), nausea and vomiting (8/20), and urinary retention (4/14). No apnea was observed. Ventilation control was studied in seven children. No significant change in resting respiratory variables occurred after both surgery and epidural morphine injection. However, the slope of the ventilatory response to CO2was significantly (P< 0.05) decreased after surgery but before morphine, as compared with its preoperative control value (0.84 ± 0.44 versus 1.51 ± 0.72 1 · min−1· mmHg-1), and remained low for 22 h after epidural morphine (0.90 ± 0.57 1 · min−1· mmHg−1). Sixty minutes after morphine injection, the plasma morphine concentration was always less than 12 ng-ml−1in the seven children studied. Pharmacokinetic parameters were similar to those observed after epidural injection of morphine in adults, except for a shorter terminal half-life (73.8 ± 41.6 min) attributed to a greater total body clearance of morphine in the children (28.3 ± 3.4 ml ·min−1·kg−1). It is concluded that epidural morphine provides effective and prolonged analgesia in children after abdominal and urologic surgery and that it is associated with prolonged respiratory depression that requires close monitoring for at least 24 h.

ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Severe hypoxemia causes respiratory and cardiac arrest, in part, because severe hypoxemia decreases glycolysis and adenosine triphosphate (ATP) production by a lactic acid-induced decrease in the activity of phosphofructokinase and glyceraldehyde-3-P dehydrogenase. Fructose-1,6-diphosphate (FDP) administration increases the ATP concentration of blood. The authors hypothesized that FDP might increase the number of rabbits that coicular euld be resuscitated from hypoxemic cardiac arrest. To test this hypothesis, heart rate, arterial pressure, left ventrnd-diastolic pressure, and blood gases andpH were measured during normoxemia (FIO2=0.21) and again during hypoxemia (FIO2=0.04) in 28 adult, white, New Zealand rabbits anesthetized with pentobarbital. With the onset of hypoxemia, we gave either 40 mg/kg of 5% FDP (n = 10), 5% glucose (n = 11), or an equal volume (2.5 ml) of normal saline (n=7) intravenously and began a continuous infusion of 2.0 mg · kg-1· min-1of the same sugar or 0.12 ml/min of saline. FDP-treated rabbits breathed for 20.9 ± 4.9 (mean ± SEM) min after initiation of hypoxemia; glucose-treated rabbits breathed for 1.4 ± 0.2 min, and saline-treated rabbits breathed 10.3 ± 4 min. Cardiac arrest occurred 2.5 ± 0.5 min after the onset of respiratory arrest in FDP-treated rabbits, 4.1 ± 0.2 min in glucose-treated rabbits, and 2.9 ± 0.4 min in saline-treated rabbits. We could resuscitate all ten FDP-treated rabbits; two of 11 glucose-treated (FDP vs. glucose,P< 0.001); and one of seven saline-treated rabbits (FDP vs. saline,P< 0.001) from cardiac arrest. It is concluded that FDP prolongs the time to respiratory arrest and increases immediate salvage from cardiac arrest in severely hypoxemic, adult rabbits.

ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Isoflurane (ISF)-induced hypotension causes equal reductions of cerebral blood flow (CBF) and the cerebral metabolic rate for oxygen (CMRO2) so that no disturbance of cerebral energy stores or metabolites occurs. While hypocapnia during ISF-induced hypotension causes a further reduction of CBF, the effects on cerebral energy stores and metabolites produced by combining hypocapnia with ISFinduced hypotension are not known. This study examined the effect of hypocapnia (PaCO2=20mmHg) on CMRO2, the electroencephalogram (EEG), and levels of adenine nucleotides, phosphocreatine, lactate, pyruvate, and glucose in brain tissue in 12 dogs during ISF-induced hypotension. All dogs were examined at: 1) normocapnia with normotension; 2) hypocapnia with normotension; 3) hypocapnia combined with ISF-induced hypotension to cerebral perfusion pressures of 60, 50, and 40 mmHg; and 4) restoration of normocapnia with normotension. In six dogs CMRO2was determined, and the EEG was evaluated using compressed spectral analysis. In the other six dogs brain tissue metabolites were determined. Hypocapnia combined with ISF-induced hypotension (all levels) caused a decrease of the power of the beta-2 spectra, an increase of the power of the alpha and beta-1 spectra, but no change in total power of the EEG. There was no change in cerebral energy stores or brain tissue metabolites. CMRO2was reduced by approximately 27%. Thirty mintues after restoration of normocapnia with normotension, cerebral metabolites remained unchanged and CMRO2, and the power of the alpha, beta-1, and beta-2 spectra of the EEG returned to control values. These results suggest no adverse effect on cerebral metabolism or function during hypocapnia combined with ISF-induced hypotension.

ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

In unanesthetized dogs prepared with chronic tracheostomies and chronically implanted intrathecal (IT) catheters having openings in the cisterna magna and lumbar region, lumbar IT injection of DAla2- D-Leu5-enkephalin (DADL, 1–10 mg) and morphine (3–30 mg) produced a dose-dependent depression of the slope of the CO2response function (minute expired volume [VE]vs. end-tidal [ET] CO2) as investigated by a modified Read rebreathing technique. The maximum depression occurred less than 3 h after IT injection of either agent and lasted as long as 12 h. The depression was totally reversed by naloxone (0.4 mg/kg, iv). Naloxone alone had no effect on ventilatory function. After 10 mg DADL, there was no significant change in heart rate (HR), mean arterial pressure (MAP), mean pulmonary artery pressure (MPAP), cardiac output (CO), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), or Pao, during the 3 h postinjection. In contrast, PaCO2, was significantly elevated andpH significantly decreased (P < 0.05). Naloxone administration after high-dose IT DADL resulted in a doubling of MABP, MPBP, CO, and SVR that lasted approximately 20 min. In concurrently measured cisternal cerebrospinal fluid (CSF) levels, both morphine and DADL displayed peak levels by 30–60 min. The lumbar CSF clearance curves for both agents were fitted with a two-compartment intravenous bolus model. The t½α was 13.8 ± 3.6 min for DADL and 9.4 ± 1.6 min for morphine (mean ± SE). The t½β was 101.3 ± 17.7 min for DADL and 116.7 ± 27.9 min for morphine. The volume of distribution at steady state (Vd88) was 1.6 ± 0.88 ml/m2for DADL and 3.4 ± 2.1 ml/m2for morphine. The clearance was 29.6 ± 1.7 µl · min−1· m 2 for DADL and 41.6 ± 12.7 µl · min−1· m−2for morphine. DADL may represent an alternative to morphine for IT administration, especially in morphine-tolerant patients.

ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The effects of hypotension, hemodilution, and their combination on the relationship between concurrent brain electrical activity and resulting brain injury were studied in anesthetized monkeys. The authors compared changes in the electroencephalogram and somatosensory and auditory evoked potentials with eventual neuropathologic outcome. Our goals were: 1) to define the margin of safety for the monkey brain during hemodilution and hypotension under several simulated clinical conditions; and 2) to determine whether noninvasive measurements of brain electrical activity can predict ischemic brain cell damage. Forty-one monkeys were anesthetized with halothane (0.8 vol % inspired) and ventilated mechanically. Arterial hypotension was induced with trimethaphan (25 ± 8 mmHg mean arterial blood pressure [MABP] for 30 min). Hemodilution was induced by replacing blood with lactated Ringer's solution (14 ± 2% hematocrit for 1 h). Combined hemodilution and hypotension consisted of 30 min of hemodilution alone followed by superimposing hypotension for 30 min (16 ± 3% hematocrit and 29 ± 5 mmHg MABP). Ten monkeys died following severe hypotension alone or combined hemodilution and hypertension as a consequence of cardiac arrest or undetermined (possibly neurologic) causes. No histologic evidence of ischemic brain cell injury was found in surviving monkeys subjected to hemodilution or hypotension alone. Neuropathologic alterations in the cerebral cortex, cerebellum, hippocampus and globus pallidus as well as neurologic and behavioral deficits were found in seven of 16 surviving monkeys subjected to both hemodilution and hypotension. These findings resulted from combinations of hematocrit less than 20% and MABP below 40 mmHg. Only the degree of amplitude reduction in cortical components of the somatosensory evoked potentials during the stress period indicated a high probability of neuropathologic outcome.

ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The reproductive and teratogenic effects of lidocaine were studied in 155 Sprague-Dawley rats chronically implanted with osmotic minipumps. Three different lidocaine doses were used as follows: a low dose (100 mg · kg−1· day−1); an intermediate dose (250 mg · kg−1· day−1); and a high dose (500 mg · kg−1· day−1). In the low and intermediate dose groups, lidocaine was administered for two weeks before mating and throughout pregnancy to evaluate reproductive and teratogenic effects. In the high-dose group, lidocaine was administered from days 3 to 17 of pregnancy to evaluate teratogenic effects. On day 21, cesarean section was performed and all of the 1,040 offspring, including those from control and positive control (retinoic acid) groups, were preserved and subsequently examined microscopically to detect external, visceral, and skeletal abnormalities. None was found in lidocaine-treated groups; reproductive indices also were normal. The only treatment effect was a reduction in mean fetal weight in the high-dose group. In a subsequent experiment this was found to be secondary to slightly delayed fetal development. It is concluded that lidocaine is devoid of significant adverse reproductive and teratogenic effects in Sprague- Dawley rats.

ISSN:0003-3022    

出版商:OVID    

年代:1986

数据来源: OVID