Ma zui xue za zhi = Anaesthesiologica Sinica最新文献

The value of preanesthetic assessment of anemia and analysis of the hemoglobin level prior to a minor pediatric surgery has been recently questioned in some reports. This study was to retrospectively analyse 8859 pediatric patients who underwent minor surgery in the period from January 1987 to December 1990 in our hospital. They were all ASA class I-II in physical status with age ranging from one month to 19 years. Those patients with their hemoglobin values determined at other laboratories or hospitals in spite of our recognition and those suspected of having an immune or oncologic disease were excluded from this study. The mean hemoglobin value of the patients under study was 12.99 +/- 0.82 g/dl. 0.62% of the patients (55) were found to have hemoglobin values less than 10 g/dl which were similar to the results obtained by Wood et al (0.7%) in 1981 and Roy et al (0.5%) in 1990. Among the 55 anemic patients, 41 (74.5%) were at the age between 2 to 4 months (within the physiologic anemic period of infancy). Sampling of blood for routine preanesthetic hemoglobin determination which caused discomfort and pain was often rejected by pediatric patients and struggle for escape also upset the children very much. Based on the results from our analysis, we suggest that in healthy pediatric patient scheduled for minor surgery routine hemoglobin test could be excluded. Hemoglobin test is selectively performed in a patient is anemic or under suspicious circumstances. The value and shortcomings of selective hemoglobin test before surgery require further evaluation.

In a randomized blind study, we compared the neonate Apgar score, umbilical venous pH, incidence of maternal hypotension and intra-operative maternal discomfort in elective Cesarean section performed under spinal anesthesia in two groups of parturients with or without low dose midazolam as a sedative agent before the deliveries. Each group consisted of 20 parturients. Ninety percent of the mothers in the midazolam group fell asleep smoothly before the operations started. The neonates in the midazolam group were scored similar to saline control group on Apgar score and umbilical venous pH. The incidences of maternal hypotension during operation in both groups were 55%. However, the occurrence of intra-operative maternal discomfort was eleven fold more often in the saline control group. On the other hand, there existed a significant inverse correlation between uterine incision-delivery interval and Apgar score as well as umbilical venous pH. We concluded that low dose midazolam is a good sedative agent during spinal anesthesia in elective Cesarean section. It is also safe and effective even given before delivery.

The patient undergoing open-heart surgery depends on hypothermia and cardiopulmonary bypass (CPB) to maintain organ perfusion during cardiac arrest. Increased blood viscosity during hypothermic CPB might be life-threatening, so hemodilution is imperative. Fourteen open-heart patients of ASA class II-III were included in this study. Pre- and intra-CPB viscosity changes were observed. Before CPB, 6 ml blood sample was drawn out from open-heart patients after systemic heparinization and another 6 ml blood sample was drawn out from the oxygenator after CPB was established. The hematocrit and relative viscosity of each sample in different temperatures were measured. The result revealed that as the temperature decreases, the viscosity of each sample increases apparently. As compared to the pre-CPB blood sample, the hematocrit of blood obtained intra-CPB decreases from 36.81 to 27.04, (p < 0.001), and the viscosity also decreases at all different temperatures (p < 0.001). Blood viscosity obtained at 37 degrees C pre-bypass is not statistically different from the sample at 25 degrees C during bypass. Obviously, increased viscosity due to hypothermia is buffered by hemodilution after using large amount of fluid as priming solution during CPB. Therefore, the hematocrit and viscosity remain within physiologic ranges.

Premedication is one of the popular techniques in anesthesia, not only for the decrease of side effects but also for the increase of actions. Clinically, we found that plasma neuropeptide Y-like immunoreactivity (NPY-IR) was lowered in patients who had received premedication. In rats, plasma NPY-IR was not modified by the intravenous injection of diazepam. Pethidine reduced the plasma NPY-IR level which could be reversed by naloxone. Direct inhibition of plasma NPY-IR through an activation of opioid receptors can thus be considered. To the cold-stress stimulation, plasma NPY-IR was markedly raised. Diazepam reduced this stimulation-induced increase of plasma NPY-IR in a dose-dependent manner. Similar derivative of benzodiazepine produced an inhibition in a way following the potency as that to produce anxiolytic action. Also, this inhibition was reversed by PK11195, an antagonist of peripheral benzodiazepine receptors. Moreover, pain-stimulated increase of plasma NPY-IR in rats was also reduced by pethidine. This action was totally reversed in the presence of naloxone, indicating the participation of opioid receptors in the process. The obtained results suggest that premedication of diazepam and/or pethidine has the ability to decrease plasma NPY-IR in animals.

The analgesic effect of subarachnoid administration of tetracaine combined with low dose morphine or nalbuphine for spinal anesthesia was evaluated in 60 ASA physical status class I or II patients. Dextrose solution (10%) was added to 0.4 mg morphine or 0.4 mg nalbuphine to make a total volume of 2 ml, which was injected intrathecally with tetracaine in a double-blind, randomized fashion. Vital signs, sensory level, motor block, pain score, and side effects were recorded every 2 min for the first 15 min and then at 15, 30, 45, and 60 min and at 30-min intervals until the patient complained of pain. Side effects and opioid requirements were recorded for the first 24 h. Complete analgesia (time from injection to first report of pain) lasted 180 +/- 51.6 min in the control group and increased to 238 +/- 71 min in group with addition of 0.4 mg nalbuphine, 250 +/- 74 min in group with addition of 0.4 mg morphine (p less than 0.05). The effective analgesia (time from injection to first opioid requirement) also increased in groups of nalbuphine and morphine than the control group. No differences in complete or effective analgesia was found between groups in the presence of nalbuphine or morphine. Results indicate that the addition of 0.4 mg nalbuphine or morphine to hyperbaric tetracaine for spinal anesthesia improves the quality of intraoperative analgesia and can last into the postoperative period. Side effects were less in nalbuphine group than with morphine group.