Intravenous Administration Of Propofol Research Articles

Epidural anesthesia with bupivacaine, bupivacaine and fentanyl, or bupivacaine and sufentanil during intravenous administration of propofol for ovariohysterectomy in dogs

To compare cardiovascular and systemic effects and analgesia during the postoperative period of epidural anesthesia performed with bupivacaine alone or with fentanyl or sufentanil in bitches maintained at a light plane of anesthesia with continuous infusion of propofol. Prospective randomized masked clinical trial. 30 female dogs of various breeds. Dogs were allocated into 3 groups of 10 each. One group received fentanyl (2 microg/kg [0.91 microg/lb]) and bupivacaine (1 mg/kg [0.45 mg/lb]), 1 group received sufentanil (1 microg/kg) and bupivacaine (1 mg/kg), and 1 group received bupivacaine (1 mg/kg). All dogs received acepromazine (0.1 mg/kg [0.045 mg/lb]) and continuous infusion of propofol for sedation. The agents were administered into the lumbosacral space and diluted in saline (0.9% NaCl) solution to a total volume of 0.36 mL/kg (0.164 mL/lb). Cardiac and respiratory rates, arterial blood pressures, pH, and blood gases were evaluated. Analgesia, sedation level, serum cortisol concentrations, and plasma catecholamine concentrations were measured regularly for 6 hours. No important changes in cardiovascular, respiratory, or sedation variables were observed. Degree of analgesia in the postoperative period was higher in the sufentanil group, although use of fentanyl and bupivacaine also resulted in a sufficient level of analgesia. Use of the 3 anesthetic techniques permitted ovariohysterectomy with sufficient analgesia and acceptable neuroendocrine modulation of pain with minimal adverse effects.

Severity and duration of mental deficiency symptoms after intravenous administration of propofol

The severity and duration of cognitive performance capacity deficits after intravenous administration of propofol were determined using the validated psychological test procedure syndrome short test (SKT), a simple reaction test and original driving licence exam questions. The test battery was performed before, immediately after, as well as 1 and 2 h after propofol administration in 23 persons. Immediately after propofol anaesthesia, six individuals had a slight performance loss, and four subjects showed mild deficits, consistent with medium organic neuropsychologic disorder or dementia. The status of the subjects rapidly changed for the better, and 2 h after propofol anaesthesia, only one person (4%) showed slight deficits of memory and attention. Therefore, it is suggested that patients refrain from any participation in road traffic for at least 2 h after propofol anaesthesia. Driving a car should not be admitted until an interval of 6 h has elapsed.

Randomized clinical trial comparing regional and general anaesthesia in minimally invasive video-assisted parathyroidectomy

This randomized clinical trial was performed in a single institution to compare the results of minimally invasive video-assisted parathyroidectomy (MIVAP) conducted under regional anaesthesia (RA) or general anaesthesia (GA). Fifty-one patients undergoing MIVAP for primary hyperparathyroidism were assigned randomly to either RA (26 patients) or GA (25). RA involved a bilateral deep cervical block, and local infiltration of the incision site with a mixture of 0.25 per cent lignocaine and 0.15 per cent bupivacaine. GA was induced by intravenous administration of propofol, remifentanil and rocuronium bromide. The two groups were matched for age, sex, adenoma size, and preoperative serum calcium and parathyroid hormone levels. The interval from skin incision to closure was similar in the two groups (27.6 and 25.8 min for RA and GA respectively), whereas the total operating time (from induction of anaesthesia to return to the ward) was significantly lower with RA (72.1 versus 90.2 min; P = 0.001). The postoperative requirement for pain medication, measured in terms of amount of ketorolac administered at the request of the patient, was significantly lower in the RA group (28.5 versus 80 mg/day; P < 0.001). MIVAP performed under RA was associated with a shorter overall operating time and a reduced need for postoperative pain relief.

A Prospective Evaluation of Anesthesia for Posterior Lumbar Spine Fusion: The Effectiveness of Preoperative Epidural Anesthesia With Morphine

A prospective, randomized, single-blinded study. To prospectively compare the anesthesia for posterior lumbar spinal fusion between the age- and gender-matched groups with and without preoperative epidural anesthesia with morphine. To reduce the blood loss, hypotensive anesthesia is frequently used in the spinal fusion. However, in spite of administration of the hypotensive agents, inadequate analgesia during operation often causes unfavorable and unexpected elevation of blood pressure resulting in excessive bleeding. As well, intractable wound pain sometimes occurs after spinal fusion due to inadequate analgesia during surgery. Forty cases of posterior lumbar spinal fusion were investigated prospectively. Twenty patients underwent preoperative epidural anesthesia with morphine and sedation by continuous intravenous administration of propofol but without administration of any kind of anesthetics, including intraoperative and/or postoperative epidural anesthesia (Group E). Another 20 patients underwent inhalation general anesthesia with sevoflurane and intermittent intravenous administration of fentanyl without any regional block (Group F). In these groups, dynamics and average mean blood pressure during surgery, blood loss during surgery, postoperative requirement of analgesics, the visual analogue scale, and accuracy of neurologic evaluation immediately after surgery were analyzed. The average mean blood pressure during surgery was significantly lower in Group E than Group F: 57.1 mm Hg and 72.8 mm Hg, respectively. In addition, the dynamics of blood pressure were more stable in Group E than Group F. The blood loss during surgery was significantly less in Group E than in Group F: 546 g and 631 g, respectively. The patients of Group E required analgesics after surgery less frequently, and the rating on the visual analogue scale was significantly lower in Group F on the first, second, and third days after surgery. It was difficult to evaluate the neurologic status accurately in 5 patients of Group F because of the inadequate emergence immediately after surgery. There were no patients in Group E whose neurologic status was unclear because of the paralysis caused by epidural anesthesia. To combine preoperative epidural anesthesia with other anesthetic procedure for spinal fusion contributes to maintain more stable hypotension during surgery. As a result, it will be possible to lessen the bleeding during surgery. In addition, the postoperative pain was easily controlled with administration of fewer analgesic agents in patients who underwent the epidural anesthesia. The effectiveness of pre-emptive analgesia should be emphasized to diminish the postoperative pain.

SEDATION OF SIMULATED ICU PATIENTS USING REINFORCEMENT LEARNING BASED CONTROL

The Intensive Care Unit (ICU) is a challenging environment to both patient and caregiver. Continued shortages in staffing increase risk to patients. To evaluate the use of intelligent systems in the improvement of patient care, an intelligent agent was developed to regulate ICU patient sedation. A temporal differencing form of reinforcement learning was used to train the agent in the administration of intravenous propofol in simulated ICU patients. The agent utilized a well-studied pharmacokinetic model to calculate the distribution of drug within the patient. Pharmacodynamics were then estimated for the drug effect. A derivative of the electroencephalograms, the bispectral index, served as the system control variable. The agent demonstrated satisfactory control of the simulated patient's consciousness level in static and dynamic setpoint conditions. The agent demonstrated superior stability and responsiveness when compared to a well-tuned PID controller, the control method of choice in closed-loop sedation control literature.

Dose effects of propofol on hemodynamic and cytokine responses to endotoxemia in rats

Our previous studies have demonstrated that propofol inhibits hypotension, metabolic acidosis, and cytokine responses and reduces mortality in endotoxemic rats. The purpose of this study was to elucidate whether these beneficial effects of propofol on hemodynamics and cytokine responses were dose related. Forty-eight rats were divided at random among four equal groups: groups S, M, and L received intravenous propofol administration (5, 10, and 20 mg.kg(-1).h(-1), respectively) immediately after endotoxin (Escherichia coli endotoxin; 15 mg.kg(-1), i.v.) was given. Group E received endotoxin alone. We assessed hemodynamics and plasma cytokine [tumor necrosis factor (TNF)-alpha and interleukin (IL)-6] concentrations for 5 h following endotoxin injection. Systolic arterial pressure (SAP) was significantly higher at 4 and 5 h in groups S and M than in group E (P < 0.05), although SAP decreased progressively in all groups. Endotoxin injection increased the TNF-alpha and IL-6 concentrations in all groups. The increase in TNF-alpha concentrations at 2 h was significantly lower in group M than in group E (P < 0.05). On the other hand, the increase in IL-6 concentration at 5 h was significantly lower in groups M and L than in group E (P < 0.05). The effects of propofol on blood pressure and cytokine responses were influenced by the dose of propofol, although the relationship did not follow simple linearity.

Efeitos eletrocardiográficos do butorfanol em cães anestesiados pelo desfluorano

Objetivou-se com este experimento avaliar as possíveis alterações eletrocardiográficas decorrentes do uso do butorfanol em cães, durante anestesia geral inalatória com desfluorano. Para tal, foram utilizados vinte cães adultos, clinicamente saudáveis, distribuídos em dois grupos (n=10) denominados de GS e GB. Os animais foram induzidos à anestesia com propofol (8,4 ± 0,8mg kg-1, IV) intubados com sonda orotraqueal de Magill e submetidos à anestesia inalatória pelo desfluorano (10V%). Decorridos 40 minutos da indução, foi administrado aos animais do GS, por via intramuscular, 0,05mL kg-1 de solução fisiológica a 0,9% (salina), enquanto que no GB, foi aplicado butorfanol na dose de 0,4mg kg-1 pela mesma via e em volume equivalente ao empregado no grupo anterior. As observações das variáveis freqüência cardíaca (FC), duração e amplitude da onda P (Ps e PmV), intervalo entre as ondas P e R (PR), duração do complexo QRS (QRSs), amplitude da onda R (RmV), duração do intervalo entre as ondas Q e T (QT) e intervalo entre duas ondas R (RR) tiveram início imediatamente antes da aplicação do opióide ou salina (M0). Novas mensurações foram realizadas 15 minutos após a administração do butorfanol ou salina (M15) e as demais colheitas foram realizadas à intervalos de 15 minutos, por um período de 60 minutos (M30, M45, M60 e M75). Os dados numéricos destas variáveis foram submetidos à Análise de Perfil (p&lt;0,05). A freqüência cardíaca apresentou alteração no GB, com média de M0 maior que as demais enquanto que os intervalos RR e QT apresentaram valores de M0 menor que os demais no GB. Os resultados obtidos permitem concluir que a administração do butorfanol em cães submetidos à anestesia pelo desfluorano reduz a freqüência cardíaca e promove retardo na repolarização ventricular.

Effects of desflurane, sevoflurane and isoflurane on pulmonary shunt in dogs during spontaneous ventilation

The aim of this study was to compare the effects of desflurane, sevoflurane and isoflurane on pulmonary shunt in dogs during spontaneous ventilation. General anesthesia was induced in 30 healthy, adult, mongrel dogs by intravenous administration of propofol. The animals were separated into three groups of 10 dogs each and submitted to general inhalation anesthesia with 1.5 MAC of desflurane (G1), sevoflurane (G2) and isoflurane (G3). Arterial blood was collected by puncture of the right femoral artery, and mixed blood was collected by introducing a Swan-Ganz catheter into the pulmonary artery. These samples were used to determine the parameters employed for calculation of the intrapulmonary shunt. Measurements began at 20min after orotracheal intubation and were repeated every 20min, totaling six measurements. Means were compared by the Student t-test (P&lt;FONT FACE=Symbol&gt;£&lt;/FONT&gt; 0.05). Desflurane led to a higher shunt than sevoflurane and isoflurane at 40 and 60min. At 80min, the mean values obtained for desflurane were higher than those obtained for isoflurane, while at 100min the values observed for dogs anesthetized with desflurane were higher than those obtained with sevoflurane. Desflurane caused respiratory depression by reducing PaO2, and a higher percentage of intrapulmonary shunt than isoflurane and sevoflurane.

The anaesthetic agent propofol interacts with GABA B-receptors: an electrophysiological study in rat

The mode of action by which propofol induces anaesthesia is not fully understood, although several studies suggest that the compound acts via potentiation of brain GABA A-receptors. The aim of the present study is to investigate a putative GABA B-receptor agonistic action of propofol. For this purpose the action of propofol on a GABA-receptor mediated regulation of dopamine neurons was analyzed with extracellular single unit recordings of dopaminergic neurons of the substantia nigra in chloral hydrate anaesthetized rats. Intravenous administration of propofol (1–16 mg/kg) was found to dose-dependently decrease the firing rate and burst firing activity of nigral DA neurons. These effects by propofol were effectively antagonized by pretreatment with the selective GABA B-receptor antagonist CGP 35348 (200 mg/kg, i.v.) but not by pretreatment with the GABA A-receptor antagonist picrotoxin (4.5 mg/kg, i.v.). It is proposed that an activation of central GABA B-receptors may, at least partially, contribute to the anesthetic properties of propofol.

Cardiopulmonary and Anesthetic Effects of Isoflurane and Propofol in Hispaniolan Amazon Parrots (Amazona ventralis)

Abstract The cardiopulmonary and anesthetic effects of isoflurane and propofol were determined in 10 healthy, adult Hispaniolan Amazon parrots (Amazona ventralis). Anesthesia was induced and maintained with isoflurane in oxygen for 30 minutes. Cardiopulmonary parameters including heart rate, respiratory rate, relative arterial oxygen hemoglobin saturation (SpO2), and esophageal temperature were recorded at 1, 2, 3, 4, 5, 10, 15, 20, 25, and 30 minutes. End-tidal CO2 (EtCO2) concentrations and inspired and expired end-tidal isoflurane concentrations were recorded continuously. Before the study continued, birds were allowed to recover from isoflurane anesthesia for at least 2 hours. In a second trial, anesthesia was induced by intravenous administration of propofol (5 mg/kg) and maintained for 30 minutes by constant rate infusion of propofol (1 mg/kg per min IV). No supplemental oxygen was provided. Cardiopulmonary parameters and EtCO2 concentrations were recorded as in the isoflurane trial. Induction times...

Efeitos do desfluorano, sevofluorano e isofluorano sobre variáveis respiratórias e hemogasométricas em cães

Com este estudo objetivou-se avaliar, comparativamente, os efeitos de tres anestesicos inalatorios sobre variaveis respiratorias e hemogasometricas em caes. Para tal, utilizaram-se 30 caes sadios, adultos, machos e femeas evitando-se aquelas em estro ou em gestacao. Os animais foram separados e protocolados em tres grupos de 10 caes cada (G1, G2 e G3). Induziu-se a anestesia geral com administracao intravenosa de propofol, na dose de 10±1,3 mg/kg. Em seguida procedeu-se a intubacao orotraqueal e anestesia geral inalatoria pelo desfluorano (G1), sevofluorano (G2) e isofluorano (G3), diluidos em oxigenio a 100,00%, por meio de circuito anestesico tipo semi-fechado, dotado de vaporizadores calibrados para cada agente anestesico. As variaveis estudadas foram Frequencia Respiratoria, CO2 ao Final da Expiracao, Saturacao de Oxihemoglobina, Volume Corrente, Volume Minuto, Pressao Parcial Arterial de O2, Pressao Parcial Arterial de CO2, Excesso de Bases e pH. A avaliacao estatistica destas variaveis foi realizada pela Analise de Perfil, sendo considerado o nivel de significância de 5,00%. Os resultados obtidos permitiram concluir que o desfluorano deprime o sistema respiratorio aumentando a pressao parcial arterial de CO2 e o CO2 ao final da expiracao; e diminuindo a pressao parcial arterial de O2 e o volume minuto, quando comparado com os outros anestesicos em teste.

Clinical Comparison of Medetomidine-butorphanol and Medetomidine-buprenorphine Combinations for Intravenous Premedication of General Anaesthesia in the Dog

Rau‰er P., L. Lexmaulova: Clinical Comparison of Mmedetomidine-butorphanol and Medetomidine-buprenorphine Combinations for Intravenous Premedication of General Anaesthesia in the Dog. Acta Vet. Brno 2002, 71: 69-76. In this study we compared effects of medetomidine (10 µg/kg) with butorphanol (0.1 mg/kg) and medetomidine (10 µg/kg) with buprenorphine (0.01 mg/kg) used for intravenous premedication of general anaesthesia during surgical procedures in clinical practice. The combination of α -adrenergic substances and opioids induced within 5 min good or moderately good sedation. Anaesthesia was induced by intravenous administration of propofol to achieve loss of laryngeal reflex. General anaesthesia was maintained by a mixture of O2/N2O/halothane and, at moments of insufficient depth of anaesthesia, it was intensified by propofol re-administration. There was no difference in the dose of propofol for induction of anesthesia between abovementioned combinations used for premedication. The number of re-administrations and the total dose of propofol re-administered, however, were significantly (p < 0.05) lower when premedicating by buprenorphine. We found neither differences in respiratory and heart rates, nor in SpO2. We found significant (p < 0.05) differences in ETCO2 values at the end of anaesthesia, when its concentration was higher in dogs premedicated by the combination of medetomidinebuprenorphine. α -adrenergic drugs, opioids, analgesia, sedation, dog

Cessation of Paroxysmal Atrial Fibrillation during Acute Intravenous Propofol Administration

Cessation of Paroxysmal Atrial Fibrillation during Acute Intravenous Propofol Administration

Clinical efficacy and safety of propofol or ketamine anaesthesia in dogs premedicated with medetomidine.

Combinations of medetomidine with either propofol or ketamine were compared for the sedation and induction of anaesthesia in dogs undergoing a variety of surgical (60 per cent) and non-surgical (40 per cent) procedures. Eighty-four dogs were used at four sites. Medetomidine was administered intramuscularly at a dose of 1000 micrograms/m2 body surface area 10 to 15 minutes before the induction of anaesthesia by the administration of propofol (n = 44) or ketamine (n = 40) dosed to effect. The dogs became sedated by medetomidine after a mean (sd) time of 6.7 (5.4) minutes, and their heart rates and respiration rates decreased. Sixteen of the dogs suffered an adverse effect, 13 of them vomited. Anaesthesia was induced by the intravenous administration of propofol (2.1 [0.7] mg/kg) or ketamine (3.7 [1.9] mg/kg), and further doses of the anaesthetic were given, depending on the length of the operation, once in 17 per cent, twice in 11 per cent and three or more times in 24 per cent of the cases. The heart rate of the dogs anaesthetised with ketamine was significantly higher than that of the dogs anaesthetised with propofol, but there were no other significant physiological differences. There were 11 adverse side-effects in the ketamine group compared with five in the propofol group and they were generally more severe. The quality of the recovery from anaesthesia was considered to be smooth in 89 per cent of the propofol group but in only 63 per cent of the ketamine group.

The Peripheral Analgesic Effect of Meperidine in Reducing Propofol Injection Pain Is Not Naloxone-Reversible

Background and ObjectivesMeperidine is frequently used in general anesthesia and perioperative analgesia. In addition to its opioid action, meperidine possesses some local anesthetic properties. A preliminary study using the tourniquet venous retention technique found meperidine to be more effective in reducing propofol injection pain than fentanyl or morphine, both of which were slightly better than placebo. This study was undertaken to evaluate whether this peripheral analgesic effect of meperidine is affected by naloxone.MethodsIn a randomized, double-blind manner, after venous occlusion with a tourniquet, meperidine 40 mg was given intravenously to patients in group A (n = 31), meperidine 40 mg followed by naloxone 0.04 mg to group B (n = 32), meperidine 40 mg followed by naloxone 0.2 mg to group C (n = 30), and normal saline placebo to group D (n = 30). The venous retention of drug(s) was maintained for 1 minute, followed by tourniquet release and intravenous administration of propofol 100 mg. Pain assessment was made immediately after the propofol injection.ResultsAll three groups given meperidine had significantly less propofol injection pain (P &lt; .01) than the group given saline placebo, and there was no difference among groups A, B, and C.ConclusionThe peripheral analgesic effect of meperidine in reducing propofol injection pain is not mediated by its opioid activity.

An evaluation of new circle system of anesthesia. Quantitative anesthesia with isoflurane in new zealand rabbits

A small circuit system of anesthesia was developed by Fonseca and Goldenberg in 1993. The authors used in this study New Zealand White (NZW) rabbits under closed system anesthetic regiment by insoflurane. Twenty male adult New Zealand rabbits were distributed in two groups of ten animals. No premedicant drugs were given. Endotraqueal intubation was made after intravenous administration of propofol (10mg/kg). Insoflurane was used to anesthesia management, administred by lowflow closed system technique with cooper kettle vaporizer, fixed by pre-calculated vaporizing flow in double times intervals. The group II underwent surgical periostal scratching in the medial tibial surface at the proximal shaft. Rabbits breathed spontaneously. Hypotensio, hypercapnia and respiratory acidosis were characteristic of the cardiopulmonary effects of the anesthesia. The corneal reflex and pinch reflex was useful as reliable indicators of anesthesic depth. Manual or mechanical ventilation should be considered as a way of improving alveolar ventilation and normalize blood-gas values. The system developed by Fonseca and Goldenberg was considered suitable for anesthesic management in rabbits.

Inhibitory effects of propofol on catecholamine secretion and uptake in cultured bovine adrenal medullary cells.

In the central and peripheral noradrenergic neurons, the balance between noradrenaline release and reuptake determines the level of noradrenaline at the synaptic cleft or the nerve ending. In the present study, we examined the effects of propofol, an intravenous general anaesthetic, on catecholamine secretion and noradrenaline uptake in cultured bovine adrenal medullary cells and on the serum noradrenaline and blood pressure in rats. In cultured adrenal medullary cells, propofol (10-50 mumol/l) concentration-dependently inhibited catecholamine secretion stimulated by carbachol. Propofol suppressed carbachol-evoked 22Na+ influx as well as 45Ca2+ influx at concentrations similar to those which suppressed the catecholamine secretion. Propofol (10-50 mumol/l) also inhibited veratridine-evoked 22Na+ influx, 45Ca2+ influx and catecholamine secretion, whereas it had little effect on the 45Ca2+ influx and catecholamine secretion induced by 56 mmol/l K+. Cultured adrenal medullary cells show [3H] noradrenaline uptake which is sensitive to imipramine. Propofol (10-50 mumol/l) significantly inhibited the imipramine-sensitive uptake of [3H] noradrenaline. In rats, intravenous administration of propofol (2.5 mg/kg) lowered serum noradrenaline and arterial blood pressure. From these findings, in spite of inhibiting noradrenaline uptake, propofol at anaesthetic concentrations (10-30 mumol/l) seems to reduce catecholamine secretion by interfering with Na+ influx through voltage-dependent Na+ channels as well as nicotinic acetylcholine receptor-associated ion channels in the adrenal medulla and, probably, in the sympathetic nervous system. This may explain the propofol-induced hypotension during anaesthesia.

Magnetic Resonance Imaging of the Upper Airway

Anesthetic agents inhibit the respiratory activity of upper airway muscles more than the diaphragm, creating a potential for narrowing or complete closure of the pharyngeal airway during anesthesia. Because the underlying mechanisms leading to airway obstruction in sleep apnea and during anesthesia are similar, it was hypothesized that anesthesia-induced pharyngeal narrowing could be counteracted by applying nasal continuous positive airway pressure (CPAP). Anesthesia was induced in ten healthy volunteers (aged 25-34 yr) by intravenous administration of propofol in 50-mg increments every 30-s to a maximum of 300 mg. Magnetic resonance images of the upper airway (slice thickness of 5 mm or less) were obtained in the awake state, during propofol anesthesia, and during administration of propofol plus 10 cm nasal CPAP. Minimum anteroposterior diameter of the pharynx at the level of the soft palate decreased from 6.6 +/- 2.2 mm (SD) in the awake state to 2.7 +/- 1.5 mm (P < 0.05) during propofol anesthesia and increased to 8.43 +/- 2.5 mm (P < 0.05) after nasal CPAP application. Anteroposterior diameter of the pharynx at the level of the dorsum of the tongue increased from 7.9 +/- 3.5 mm during propofol anesthesia to 12.9 +/- 3.6 mm (P < 0.05) after nasal CPAP. Pharyngeal volume (from the tip of the epiglottis to the tip of the soft palate, assuming this space to be a truncated cone) significantly increased from 2,437 +/- 1,008 mm3 during propofol anesthesia to 5,847 +/- 2,827 mm3 (P < 0.05) after nasal CPAP application. In contrast to the traditional view that relaxation of the tongue causes airway obstruction, this study suggests that airway closure occurs at the level of the soft palate. Application of nasal CPAP can counteract an anesthesia-induced pharyngeal narrowing by functioning as a pneumatic splint. This is supported by the observed reduction in anteroposterior diameter at the level of the soft palate during propofol anesthesia and the subsequent increase in this measurement during nasal CPAP application.

Effects of propofol and thiopentone on picrotoxin convulsive threshold in the rabbit.

The purpose of the present study was to examine the effect of intravenous administration of propofol and thiopentone on picrotoxin-induced seizures using the picrotoxin convulsive threshold test in the rabbit. Neither propofol nor thiopentone at a dose of 1.25 mg/kg had any significant effect on picrotoxin seizure threshold. However, at higher doses (2.5, 5, 10 mg/kg) both propofol and thiopentone produced a significant and dose-dependent increase in the picrotoxin convulsive threshold. These findings suggest that propofol is an effective anticonvulsant against picrotoxin-induced seizures in the rabbit.

Epidural anesthesia in anin vitro fertilization and embryo transfer program

To investigate the potential advantages of epidural anesthesia in an in vitro fertilization and embryo transfer program. Between January 1991 and December 1992, 148 infertile patients underwent transvaginal ultrasound guided oocyte retrieval. A total of 44 patients (group A) had 50 retrievals under epidural anesthesia, and 104 patients (group B, control group) 112 retrievals under intravenous sedation (propofol) with mask-assisted ventilation (nitrous oxide). In group A satisfactory anesthesia was achieved in 49 of the 50 cases (98%); one patient required additional intravenous administration of propofol owing to extreme anxiety. No complications were observed. Adversely, in group B nausea was observed in 16 cases (14%) and nausea and vomiting in 7 cases (6%). In group A the fertilization, cleavage and pregnancy rates were 67.2%, 92% and 20% respectively, while in group B the rates were 69.3%, 93% and 19.6% respectively; the differences are not statistically significant. Epidural anesthesia is an effective method for transvaginal oocyte retrieval but does not improve the treatment outcome as compared to an intravenous sedation with mask-assisted ventilation using propofol and nitrous oxide.