The fetus is an unstable subject for an isolated physiological and biochemical study. To study the fetus in a controlled and stable environment, a trial was done using 12 goat fetuses. Extrauterine incubation system was devised using an extracorporeal membrane oxygenation system. The system consisted of a venous reservoir with a servo-controlled roller pump and a membrane oxygenator. The extra-corporeal circuit and membrane oxygenator were primed with the maternal whole blood of 200 mL. Fetal umbilical cords was exposed by Cesarean section. Fetal umbilical arterial blood was drained via the drainage cannula. The drained blood was perfused to the oxygenator by the roller pump. The highly oxygenated and decarboxylated blood was returned to an umbilical vein via the perfusion catheter. The blood flow rate was controlled manually using a roller pump. Fetal heart rate, blood pressure, and electrocardiogram were continuously recorded. Gas analysis of drained and perfused blood was performed hourly. With this system, the fetuses were able to survive under fairly stable physiological condition for periods of up to 34 hr. The extrauterine incubation system used in this study could therefore be a encouraging future experimental model in researching the artificial placenta for premature fetuses.

Oxytocin antagonists may be useful in inhibiting the uterine contractions of preterm labor. One such compound is TT-235 (previously referred to as Antag III). The purpose of this study was to compare the resistance of TT-235 and oxytocin to enzymatic degradation by oxytocinase in the blood of humans and baboons during their 3rd trimester of pregnancy. Blood samples from pregnant women and baboons not in labor were incubated in vitro with known amounts of oxytocin and TT-235. Samples were collected at 0, 15, 30, 45, and 60 min for oxytocin analysis and at 0, 10, 60, and 360 min for TT-235 analysis. Oxytocin was analyzed by radioimmunoassay after extraction, while TT-235 was analyzed by radioreceptor assay. In human blood, oxytocin was readily metabolized with >83% disappearance over the 60-min incubation period. In contrast, TT-235 was stable up to 360 min of incubation. In the baboon, oxytocin did not diminish over the 60-min incubation period. The level of TT-235 was similar to that in human blood without change over 360 min of incubation. This study suggests (1) that in contrast to blood from pregnant humans, blood from pregnant baboons lacks oxytocinase at least in vitro and (2) that TT-235 is resistant to enzymatic degradation by human blood, implying that this oxytocin antagonist may have a prolonged activity in vivo in humans.

Background: Intrathecal opioids in combination with bupivacaine has been shown to provide adequate sensory blockade and early recovery from spinal anesthesia. This study was investigated the added effects of intrathecal fentanyl 10 μg to bupivacaine for spinal anesthesia.Methods: Sixty patients undergoing lower extremity surgery were into three groups. Group I received bupivacaine 10 mg (0.5%), gruop II received bupivacaine 5 mg with normal saline 1 ml, and group III received bupivacaine 5 mg with fentanyl 10 μg and normal saline 0.8 ml.Results: There was no significant difference between group I and group III in the peak level and duration of sensory block. But the intensity of motor blockade was decreased in group III compared with group I and side effects of spinal anesthesia with local anesthetics was decreased in group III compared with group I. In Group II, 7 patients were complained the pain during surgery.Conclusions: Intrathecal fentanyl 10 μg with bupivacaine 5 mg on spinal blockade provide reliable anesthesia for lower extremity surgery.

Background: Rocuronium produce intense discomfort on IV injection in conscious patients. The purpose of this study was to evaluate the incidence and severity of pain associated with IV injection of rocuronium in conscious patients and to determine the efficacy of different doses of IV lidocaine at minimizing injection pain.Methods: The author evaluated 120 in-patients undergoing various elective surgeries. Patients were randomized into four groups of 30 patients for this blind, prospective study. After tourniquet application on the forearm, the patients were given saline (3 ml) (Group I, n = 30), lidocaine 20 mg (Group II, n = 30), lidocaine 40 mg (Group III, n = 30), or lidocaine 60 mg (Group IV, n = 30) diluted in a 3 ml solution. The occlusion was released after 20 seconds and rocuronium 0.6 mg/kg was injected over 10 seconds. The patients were observed and asked immediately if they had pain in the arm; responses were assessed. Five mg/kg of thiopental sodium was injected intravenously, 30 seconds after the administration of rocuronium.Results: The incidence of pain was 86.7% in group I and was significantly lower group II (60.0%), group III (36.3%), and in IV (P ＜ 0.05). In addition, patients pretreated with lidocaine were less likely to suffer moderate to severe pain. But, pain incidences and severities were similar in those that received 40 mg or 60 mg of lidocaine.Conclusions: Lidocaine was effective at relieving rocuronium-induced and doses of 40 mg and 60 mg of lidocaine were most effective.

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