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Amyotrophic lateral sclerosis (ALS) is a disease characterized by progressive degeneration of the lower motor neurons, motor nuclei of the brain stem, and the descending pathway of the upper motor neurons. As the disease progresses, atrophy and weakness involve most of the skeletal muscles, including those of the tongue, pharynx larynx and chest. Impairment of respiration, altered response to muscle relaxants, and predisposition of aspiration affect a safe anesthetic management. General anesthesia with tracheal intubation might ensure intraoperative ventilatory management, but it could also increase the risk of aspiration with its entailing airway obstruction and demand the need of postoperative artificial ventilatory support. In this report, we described the use of epidural analgesia with 2% lidocaine combined with continuous infusion of low dose propofol for sedation for a ALS patient undergoing abdominal hysterectomy. The anesthetic management of this patient was smooth and successful. Besides, epidural morphine could provide excellent postoperative pain relief without respiratory complications.

Background: Conscious sedation, not affecting the safety of both mother and fetus, is especially favorable in anxious patients undergoing Cesarean delivery. However, when sedation is started before performing intrathecal anesthesia, the infusion time before delivery will be prolonged. In this study, the incidence of maternal and fetal complications under propofol infusion were evaluated as well as the blood concentrations of propofol during delivery at different time of sedation., Methods: Maternal and fetal effects of pre-spinal sedation with low dose propofol infusion technique (3 mg/mg/h following 0.3 mg/kg bolus) in 37 Cesarean parturients were evaluated, compared with another 33 parturients under spinal anesthesia without any sedatives., Results: The induction to delivery time was 32.6 +/- 7.7 min. Satisfactory, airway-maintaining conscious sedation was shown without increasing the incidence of post-spinal hypotension and hypoxemia compared with non-sedative group. The plasma propofol concentrations in the mean time of delivery in maternal vein and umbilical vein were 0.86 +/- 0.29 and 0.33 +/- 0.11 microgram/ml, respectively. Umbilical venous concentration neither correlated with infusion time nor exceeded the maternal venous concentration. The 1-min and 5-min Apgar scores as well as umbilical venous blood gas analyses did not differ significantly between two groups., Conclusions: Conscious sedation by low dose propofol infusion is safe for both mother and fetus in spite of longer infusion time.

Background: A simple sedative technique without inducing oversedation or amnesia for birth experience would be necessary for patients undergoing Cesarean section receiving regional anesthesia. Clinical effects and dose requirement of intravenous propofol infusion were evaluated for this purpose., Methods: Forty-five parturients under adequate spinal anesthesia were randomly assigned to three groups and propofol was given after the clamping of the umbilical cord. The loading doses and initial infusion rates for group A, B, C were 0.3, 0.4, 0.5 mg/kg and 3, 4, 5 mg/kg/h, respectively., Results: Oversedation was not found and verbal contact was maintained in patients of group A and B. Two patients in group C were oversedated. Cardiovascular and respiratory function remained stable in all three groups. The incidences of complete amnesia for the experience of baby shown and intraoperative nausea/ vomiting were low. Most patients were satisfied with the sedation technique., Conclusions: Intravenous infusion of propofol with a rate of 3-4 mg/kg/h after 0.3-0.4 mg/kg bolus injection is a sale, simple and satisfactory intraoperative postdelivery sedation technique in elective patients undergoing Cesarean section under spinal anesthesia.

The acronym HELLP describes a syndrome of (H) hemolysis, (EL) elevated liver enzymes, and (LP) low platelets, which symptomatically defines a unique group of preeclamptic/eclamptic women. Pregnancies complicated by this syndrome are associated with poor maternal and fetal outcome. This poses a considerable challenge to the anesthesiologists as many of these patients require emergent Cesarean section. We reported a 30-year-old woman with gestation of 32 wk who sustained Cesarean section under the impression of pregnancy with HELLP syndrome. General anesthesia was performed for this patient. The preoperative evaluation, general management, and intraoperative monitoring system were described. The individual role and use of labetalol and propofol were also discussed in this report.

A 2-year-old patient of Goldenhar's syndrome received an operation for corneal transplantation. Difficult endotracheal intubation from the congenital anomaly was treated with laryngeal mask airway and pediatric fiberoptic laryngoscope. Long-term propofol infusion (> 10 h) for anaesthetic maintenance in this small child was used with rapid and smooth recovery.

We have compared the in vivo and in vitro effects of propofol on cytochrome P450-dependent monooxygenase activities in hamster liver microsomes. Propofol (Diprivan) 10 mg/100 g body weight was injected i.p. twice a day for 2 weeks to induce cytochrome P450 enzymes. Liver microsomes were prepared by differential centrifugation. Metabolism of the cytochrome P450-dependent mono-oxygenase system was evaluated by measuring aniline hydroxylation, benzphetamine demethylation and benzo(a)pyrene hydroxylation. Defluorination of enflurane was assayed by detecting free fluoride metabolites. At similar concentrations as in the in vivo group, propofol in vitro exhibited concentration-dependent inhibition of metabolism of benzphetamine and benzo(a)pyrene. Aniline hydroxylation and defluorination of enflurane were inhibited to 78% of control with propofol 0.25 mmol litre-1. In propofol-treated hamsters, there was only minimal inhibitory or inductive effects on either mono-oxygenase activities or capacity for defluorination. This difference between the in vitro and in vivo effects of propofol on cytochrome P450 mono-oxygenase activities emphasizes the need for care when comparing in vitro and clinical data.

We compared the measurement of propofol concentrations in plasma or whole blood by high-performance liquid chromatography (HPLC) to that of gas chromatography (GC). Blood samples were collected from patients who had received bolus injection or continuous infusion of propofol. The results showed that the two methods correlated well both in plasma and whole blood samples. However, significant biphasic differences of propofol concentrations between plasma and whole blood specimens were observed in the bolus injection group. Differences were larger in the infusion group. This discrepancy in concentrations resulted from the infusion or clearance of propofol, and the lag of redistribution across blood cell membranes. In conclusion, monitoring of propofol concentrations by the methods of GC and HPLC gives equivalent results. For propofol concentration monitoring, plasma samples are preferred, but immediate centrifugation is needed.

We have studied the effect of propofol on the cytochrome P450-dependent mono-oxygenase system in human liver microsomes by assaying mono-oxygenase activities toward specific cytochrome P450 isoform test substrates, aniline, 7-ethoxycoumarin, benzphetamine and benzo(a) pyrene. Propofol inhibited benzo(a)pyrene hydroxylation to a greater extent than the oxidative metabolism of the other test substrates, even at 0.05 mmol litre-1. The degrees of inhibition of benzphetamine N-demethylation and 7-ethoxy-coumarin O-de-ethylation were similar, while aniline hydroxylation was least affected by propofol. Spectral analysis showed that propofol competed with carbon monoxide for binding to the haem moiety of haemoprotein in the P450 enzyme. The variable inhibition observed may be caused by the differential binding of propofol to P450 isoforms. Propofol 0.05-1.0 mmol litre-1 exhibited a concentration-dependent inhibitory effect on human cytochrome P450 2E1, 2B1 and 1A1. These inhibitory actions of propofol on human liver microsomal enzymes in vitro suggest that potential drug interactions may exist between propofol and other drugs administered clinically.

Propofol, like the benzodiazepines, activates the GABAA receptor-chloride ionophore complex; they potentiate one another. Since neither pharmacodynamic nor pharmacokinetic data concerning drug interaction between flumazenil and propofol is available, and especially considering the relationship of binding sites, flumazenil, the antagonist of benzodiazepines, was investigated to determine its effect upon recovery from propofol anaesthesia. Forty women receiving dilatation and curettage procedures were included in this double-blind test. After 50 micrograms fentanyl, propofol 2 mg.kg-1 was injected for induction and followed by infusion at the rate of 15 mg.kg-1.hr-1. After the operation, patients were given normal saline (Group A) or flumazenil 10 micrograms.kg-1 (Group B) randomly. Recovery time in Group A was 15.2 +/- 5.1 min and Group B 15.8 +/- 4.8 min. Propofol concentrations at the end of infusion were 4.17 +/- 1.33 micrograms.ml-1 (Group A) and 4.03 +/- 1.45 micrograms.ml-1 (Group B); these then declined to 1.22 +/- 0.17 micrograms.ml-1 (Group A) and 1.18 +/- 0.15 micrograms.ml-1 (Group B) when patients were able to open their eyes on command. No significant differences were found between the groups based on propofol concentrations and recovery time, nor did haemodynamic changes differ between them after administration of reversal agents. It was concluded that flumazenil 10 micrograms.kg-1 does not influence recovery from propofol anaesthesia.

To compare the arterial and venous concentration differences of propofol, six healthy adult patients received a propofol infusion by the Bristol three-stage manual stepdown technique. Both the mean arterial and venous concentrations of propofol remained relatively stable during the 40-min infusion. Simultaneous blood sampling from the artery and vein during the infusion period resulted in arterial concentrations significantly higher than venous concentrations. This relationship was reversed after stopping the infusion. The mean +/- SD (range) venous to arterial concentration differences were -28.8% +/- 18.3% (-71% to 1.7%) during the infusion and 18.9% +/- 13.4% (-1.5% to 40.9%) after the infusion. We conclude that venous concentrations were not useful to estimate the arterial value during and after a stepdown propofol infusion. Arterial sampling is more appropriate in pharmacologic studies of propofol.

A randomized, prospective study was performed to evaluate the hemodynamic changes and recovery characteristics in 60 ASA physical status class I-II unpremedicated patients undergoing gynecological laparotomies with either isoflurane anesthesia only (ISO group) or isoflurane anesthesia followed by propofol infusion (ISO-PRO group). All patients received isoflurane 0.5-1.5% and nitrous oxide (N2O) 66% in oxygen after tracheal intubation. ISO-PRO group (n = 30) received 6 mg kg-1 hr-1 propofol infusion in substitution for isoflurane 25 minutes before the end of surgery. Propofol in ISO-PRO group and isoflurane in ISO group (n = 30) were discontinued 5 minutes before the end of surgery. In both groups, N2O was administered throughout the operation until skin was closed. Hemodynamic measurements were similar between the two groups except at extubation when heart rate and blood pressure were lower in ISO-PRO group. The maximal blood pressure was also lower in ISO-PRO group. In ISO-PRO group, the time required to responsiveness to verbal commands and to orientation were significantly shorter. ISO-PRO group had better Steward's score on arrival at the recovery room and was earlier to get a full score of six. The two groups experienced similar rates of emesis and excitement either two hours or 24 hours postoperatively. We conclude that in relatively long intra-abdominal operations, replacement of isoflurane by propofol infusion 25 minutes before the end of surgery may provide stable maintenance of anesthesia and a faster recovery.

In order to investigate the possible antiemetic property of propofol at subhypnotic dosage, fifty patients scheduled for elective cesarean section under spinal anesthesia were accepted into the study. Patients were randomly given intravenous propofol 10 mg (group I) or 1 ml intralipid (group II) after delivery of the infant. Overall incidence of nausea (24% in group I and 40% in group II) and vomiting (16% in group I and 20% in group II) were not statistically different in the two groups. However, onset time to the appearance of nausea and vomiting were longer in group I (14 +/- 5.8 min vs 5.4 +/- 3.6 min). In conclusion, low dose propofol (10 mg) administered during spinal anesthesia for cesarean section failed to reduce the incidence of emesis.

Four numerical descriptors (median frequency, spectral edge frequency-95%, total power, and delta-ratio) derived from the computer-processed electroencephalogram (Neurometrics Lifescan) were analyzed for their ability to predict imminent arousal from total intravenous anesthesia with propofol. Fifteen patients undergoing minor surgical procedures without intubation were enrolled in the study. Arousal was defined as eye opening in response to verbal stimuli. During emergence from propofol, there were no significant changes among the descriptors except the delta-ratio. Significant change of delta-ratio occurred 210 seconds before patients' arousal and thereafter. An increase of delta-ratio value indicates that patients shifted from anesthetic to arousal state. It is concluded that the degree of delta-ratio change may be used for predicting patients' arousal from propofol anesthesia.

To evaluate the effects of ketamine, N2O, propofol on visual evoked potential (VEP) during fentanyl anesthesia, 14 patients undergoing transphenoid pituitary dissections were studied. Visual stimulation was done by using the goggles with red light diodes through closed eyelids and responses were recorded in one channel montage, Cz against Oz. The stimulus frequency was 1.9 flashes/sec. The VEPs were recorded from skin incision until the opening of the dura. For comparison, the preanesthesia to anesthesia values were determined. The ratio for N2 (N75) latency were 100.5 +/- 13.9% in ketamine group, 104 +/- 3.5% in N2O group, 100.5 +/- 4.2% in propofol group. The ratios for P2 (P100) latency were 97.45 +/- 5.7% in ketamine group, 101.9 +/- 3.5% in N2O group, 96.8 +/- 5.5% in propofol group. For N2P2 amplitude, the ratios were 36.3% +/- 31.4% in ketamine group, 138.5 +/- 58.0% in N2O group, 80.8 +/- 42.2% in propofol group. The percentage of inadequate recordings were 2.5 +/- 4.3% in ketamine group, 19.2 +/- 2.2% in N2O group and 20.6 +/- 16.0% in propofol group. The percentage of false positive results were 0 +/- 0% in ketamine group, 9.8 +/- 19.9% in N2O group, 12.7 +/- 13.2% in propofol group. Satisfactory anesthesia was achieved in all groups except for ketamine group which required additional medications for elevated blood pressure and intracranial pressure, and postoperative nausea and vomiting. It is concluded that there was great variability of VEP during anesthesia and surgery. Amplitude rather than latency changes were observed during anesthesia combined with fentanyl.(ABSTRACT TRUNCATED AT 250 WORDS)