[Anesthetic management of parturients with Marfan syndrome].

Ten pregnancies and 7 deliveries in 5 patients of Marfan syndrome were managed at our institution. Three patients were delivered with a cesarean section under general anesthesia, and one was delivered under epidural anesthesia. Three underwent vaginal delivery with epidural anesthesia. Two patients selected induced abortion, and one had a spontaneous abortion. Six of 7 neonates and all 5 mothers survived without any sequela. One had intrauterine fetal death due to dissection of aortic aneurysm. Simultaneous cesarean section and cardiovascular operation under cardiopulmonary bypass were performed in one case. In the parturient without progress of cardiovascular complication during pregnancy, painless labor under epidural anesthesia is our first choice to minimize hemodynamic derangement. Invasive arterial blood pressure and central venous pressure were monitored in all cases of vaginal delivery for tight hemodynamic control. Epidural anesthesia is also preferred in cases of elective cesarean section for obstetric indication. Emergency cesarean sections are performed in the cases of progressive dissection and urgent obstetric indication. General anesthesia was induced with fentanyl and midazolam to minimize cardiovascular response to tracheal intubation. We emphasize that evaluation of cardiovascular status and multidisciplinary approach are the key in the anesthetic management of parturients with Marfan syndrome.

Propofol as a continuous infusion during cardiopulmonary bypass does not affect changes in serum free fatty acids.

Perioperative myocardial infarction or ischaemia is a potential consequence of cardiac surgery and elevated free fatty acids can increase the severity of myocardial ischaemic damage. We investigated perioperative changes in serum free fatty acids, and other serum lipids, as a consequence of using propofol infusions for cardiac surgery during cardiopulmonary bypass. Twenty-five patients undergoing elective coronary artery bypass grafting were allocated to two groups. One group of 12 patients was given a continuous infusion of propofol and the other group of nine patients received intermittent boluses of midazolam as a hypnotic agent. Serum lipid concentrations were measured at four periods perioperatively. Changes in free fatty acid concentrations were similar between the two groups. Lipid concentrations related to triglyceride in the propofol group decreased on one occasion but subsequently returned to control value. On the other hand, such values in the midazolam group remained lower than control values. Propofol is not a contraindication as an anaesthetic for cardiac surgery in respect of concern regarding the effects of free fatty acids.

[Intraoperative management of heart transplantation in Japan--report of two cases].

We experienced intraoperative anesthetic management of two cases of heart transplantation in Japan. Both patients were in the end stage of cardiac failure due to dilated cardiomyopathy. One patient had had implantation of left ventricular assist system, and another patient had had implantation of automated cardioveter defibrillator. Transesophageal echocardiography was useful for the monitoring of cardiac function during the operation. Anti-arrythmic therapy including heart pacing and protection of right heart failure are important for the circulatory management of heart transplantation. The anesthesiologist is needed not only for the management of respiration and circulation but also for the prevention of infection and control of the time schedule.

Tyramine-induced endogenous noradrenaline efflux from in situ cardiac sympathetic nerve ending in cats.

With the use of dialysis technique, the effects of tyramine on in situ cardiac sympathetic nerve endings were examined in anaesthetized cats. Dialysis probes were implanted in the left ventricular myocardium, and the concentration of dialysate noradrenaline (NA) served as an indicator of NA output at the cardiac sympathetic nerve ending. Locally applied tyramine (600 microM) increased dialysate NA levels from 17 +/- 1 (pg mL-1) to 3466 +/- 209 (pg mL-1). Pretreatment with reserpine (vesicle transport NA blocker 1 microM) did not affect tyramine-induced NA efflux. The tyramine-induced NA efflux was augmented by pretreatment with pargyline (1 mM) but suppressed by pargyline (10 mM). Pretreatment with alpha-methyl-tyrosine suppressed NA efflux evoked by tyramine. These pretreatments did not affect the time course of NA efflux but only altered peak height of NA efflux. The efflux of NA evoked by tyramine was not associated with any reduction of dihydroxyphenylglycol (DHPG). In contrast, in the pretreatment with reserpine, the efflux of NA was associated with a reduction of DHPG. This result suggests that NA graduation between axoplasm and stored vesicle contributes to maintaining the axoplasmic NA level during carrier-mediated outward NA transport. The tyramine-induced NA efflux provides a close reflection of the NA content at the nerve ending. With the use of dialysis, this experimental model is suitable for studying the mechanism of sympathomimetic amine-induced neurotransmitter efflux.

Maternal or umblical venous levels of nitrite/nitrate during pregnancy and at delivery.

OBJECTIVE: This study was intended to measure serum concentrations of nitrite plus nitrate as an index of nitric oxide synthesis, in the maternal vein during pregnancy, just after a spontaneous delivery and at the puerperium, and at an elective cesarean section, and in the umblical vein and artery. METHODS: Maternal venous sera, and umblical venous and arterial sera were collected, and serum concentrations of nitrite/nitrate were measured by an automated procedure based on the Greiss reaction after reduction of nitrate to nitrite. RESULTS: Compared to a serum concentration of nitrite/nitrate at the first trimester (12-13 weeks of pregnancy), a serum concentration of nitrite/nitrate slightly increased at the second trimester (27-28 weeks), and became maximal at the third trimester (35-36 weeks), followed by a significant decrease near the term (38-40 weeks). A serum concentration of nitrite/nitrate slightly increased just after a spontaneous delivery with labor pains, and at the puerperium to levels slightly more than that at the first trimester. Serum concentrations of nitrite/nitrate in the umblical vein and artery did not differ. They were significantly higher than a serum concentration of nitrite/nitrate in the maternal vein just after a spontaneous delivery with labor pains but not at an elective cesarean section without labor pains. CONCLUSION: A decrease in maternal serum levels of nitrite/nitrate near term may support a hypothesis that NO is one of factors responsible for the maintenance of uterine quiescence during pregnancy. Moreover, the present results suggest that NO plays some role in the feto-placental circulation during a spontaneous delivery.

[Effects of changes in head and neck position on a tracheal tube cuff].

Thirteen patients were intubated with cuffed reinforced spiral tracheal tubes. Intracuff pressure and volume were measured as the position of the head and neck was altered. No significant changes in intracuff pressure and volume were observed with lateral rotation of the head. A significant increase in intracuff pressure was observed and excessive pressure (> 25 cm H2O) developed in 8 patients with head and neck flexion. A significant decrease of intracuff pressure and air-leak were observed in 9 patients with extension. Reinflated intracuff volume decreased and reinflated intracuff pressure increased significantly, and residual excessive pressure was observed in 4 patients with flexion. Both reinflated intracuff volume and pressure increased significantly, and excessive pressure was observed in 8 patients and residual air-leak developed in a patient in spite of excessive pressure with extension. The authors speculate that endotracheal tube movement by changes in head and neck position has effects on intracuff pressure and volume.

Norepinephrine efflux evoked by potassium chloride in cat sympathetic nerves: dual mechanism of action.

Using a dialysis technique, prominent efflux of norepinephrine (NE) from cardiac sympathetic nerve endings was observed under local administration of potassium chloride (KCl, 100 mM). KCl induced NE efflux was suppressed by omega-conotoxin GVIA or desipramine but residual efflux of NE was still detectable. In the presence of omega-conotoxin GVIA, KCl induced efflux of NE was augmented by pretreatment with reserpine, indicating that this efflux of NE was derived from axoplasma with neurotransporter. These data suggest that a KCl induced brisk increase in dialysate NE levels might occur as a consequence of exocytotic NE release and carrier mediated outward NE transport from nerve endings.

omega-Conotoxin GVIA and desipramine insensitive norepinephrine efflux from cardiac sympathetic nerve terminal.

Using dialysis technique, prominent accumulation of norepinephrine (NE) in the myocardial interstitial space was observed under local administration of a monoamine oxidase inhibitor (pargyline, 10 mM), and a vesicle uptake inhibitor (reserpine, 10 microM). Accumulation of NE in the myocardial interstitial space was associated with a reduction of dihydroxyphenylglycol levels. Pretreatment with omega-conotoxin GVIA (10 microM) or desipramine (10 microM) did not suppress this response. A brisk increase in dialysate NE levels might occur as a consequence of exocytotic or neurotransporter insensitive efflux of NE.

High-performance liquid chromatographic determination of myocardial interstitial dihydroxyphenylglycol.

This study describes a high-performance liquid chromatographic method with electrochemical detection (HPLC-ED) for monitoring dihydroxyphenylglycol (DHPG) in the myocardial interstitial space. Using a cardiac dialysis technique, 10-microl dialysates were sampled from the myocardial interstitial space (1-min fractions) and were injected directly into the HPLC-ED system. The in vitro quantification limit for DHPG was 250 fg in a 10-microl injection. The basal DHPG concentration of dialysate was 181+/-46 pg/ml. This system offers a new possibility for monitoring myocardial interstitial DHPG levels.

A new, concise dialysis approach to assessment of cardiac sympathetic nerve terminal abnormalities.

We applied a dialysis technique to the hearts of anesthetized cats and examined whether the concentration of dialysate norepinephrine (NE) reflected NE disposition at the cardiac sympathetic nerve terminals. Dialysis probes were implanted in the left ventricular wall, and dialysate NE concentrations were measured as an index of myocardial interstitial NE levels. Stimulation of stellate ganglia significantly increased dialysate NE responses that were suppressed by local administration of an NE-releasing inhibitor (omega-conotoxin GVIA, 10 microM). Increments in basal dialysate NE levels were correlated with concentrations of a locally administered neuronal uptake blocker (desipramine; 1, 10, and 100 microM). Desipramine (100 microM) augmented stimulation-induced dialysate NE responses. Local administration of a neuronal vesicle uptake blocker (reserpine, 1 and 10 microM) did not alter dialysate NE levels but increased dialysate dihydroxyphenylglycol levels. An NE-releasing amine (tyramine, 100 microg/ml) was locally administered to examine NE storage capacity at the nerve terminal. The tyramine-induced NE-releasing response was completely abolished by pretreatment with reserpine (1 mg/kg i.p.). Thus cardiac dialysis with local administration of a pharmacological tool offers a new, concise approach to assessment of neuronal NE release, uptake, vesicle uptake, and storage capacity by cardiac sympathetic nerve terminals.

Elevation of either axoplasmic norepinephrine or sodium level induced release of norepinephrine from cardiac sympathetic nerve terminals.

Using dialysis technique, prominent accumulation of norepinephrine (NE) in the myocardial interstitial space was observed under two different conditions: (1) local administration of a monoamine oxidase inhibitor (pargyline, 1, 10 mM), (2) local administration of a Na, K-ATPase inhibitor (ouabain, 10, 100 microM). Further, pretreatment with a vesicle uptake inhibitor (reserpine, 10 microM) augmented these responses. Either condition independently caused endogenous NE release and a brisk increase in dialysate NE levels might occur as a consequence of non-exocytotic release of NE.

Cytotoxic actions of cytokines on cultured mouse luteal cells are independent of nitric oxide.

We investigated the cytotoxic effects of various cytokines secreted by macrophages or T lymphocytes on luteal cells, and the role of nitric oxide (NO) produced by luteal cells in cytotoxic actions of cytokines. Mouse luteal cells were cultured in serum-free medium with interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) or interleukin-1 beta (IL-1 beta) alone, or with various combinations of these cytokines for 6 days. Cytotoxic actions of cytokines and NO production by luteal cells were evaluated by number of viable cells and the amount of nitrite and nitrate (stable metabolites of NO) in medium, respectively. IFN-gamma (1000 U/ml), TNF-alpha (3000 U/ml), or IL-1 beta (30 U/ml) alone, and the combination of TFN-alpha and IL-1 beta (10 U/ml) did not decrease number of viable cells and was without effects on NO production. The combination of IFN-gamma and IL-1 beta (10 U/ml) also did not decrease the number of viable cells, while it increased NO production a little but significantly. Combinations of INF-gamma and TNF-alpha, and IFN-gamma, TNF-alpha and IL-1 beta (10 U/ml) markedly decreased number of viable cells. The combination of IFN-gamma and TNF-alpha increased NO production a little but significantly, and the combination of three cytokines (IFN-gamma, TNF-alpha, and IL-1 beta) caused a greater increase in NO production. An NO synthase inhibitor, L-NG-monomethy-L-arginine (0.5 mM) or aminoguanidine (0.5 mM) abolished increases in NO production induced by combinations of IFN-gamma and TNF-alpha, and IFN-gamma, TNF-alpha and IL-1 beta completely without effects on number of viable cells. The present results indicate that combinations of cytokines including IFN-gamma and TNF-alpha induce death of cultured mouse luteal cells, and that the cytotoxic actions of these cytokines are independent of NO production by luteal cells.

Duration of apnoea in anaesthetized children required for desaturation of haemoglobin to 95%: comparison of three different breathing gases.

In this study, we compared three gas compositions to determine if the duration of apnoea for SpO2 to decrease is proportionate to the oxygen fraction of the gas prior to apnoea. Twenty-five patients ASA physical status 1-2 aged two months to 12 years were included in the study. Anaesthesia was induced via a mask with 5% sevoflurane and 66% N2O in oxygen. After paralysis with vecuronium (0.12 mg.kg-1, i.v.) the trachea was intubated and anaesthesia was maintained with sevoflurane and N2O in oxygen. When cardiovascular stability was obtained, the patient was randomly set to breathe one of three gas compositions: 1. oxygen (FiO2 1.0), 2. N2O/O2 (FiO2 0.4), and 3. air/O2 (FiO2 0.4). All three gas compositions included 2-4% of sevoflurane to maintain anaesthesia. After more than eight min of each gas breathing, apnoea was begun by disconnecting the breathing circuit from the tracheal tube. The time from the start of apnoea (SpO2 100%) to SpO2 of 95% (T95) was measured. T95 measured after breathing N2O/O2 and air/O2 were 34.6 +/- 5.7 and 28.8 +/- 4.7% of that measured after oxygen breathing (P < 0.001 vs oxygen breathing, P < 0.001 vs oxygen and N2O/O2 breathing), respectively. Preoxygenation before intubation was validated to delay the haemoglobin desaturation brought about by apnoea. An induction technique using a low FiO2 will allow rapid haemoglobin desaturation.

[FIO2 and SpO2 during cardiac surgery in neonates and infants].

Fractional inspired oxygen (FIO2) applied before and after a repair or palliative procedure for cardiac defects along with SpO2 measured by pulse oximeter were reviewed from anesthetic records of 62 neonates and infants. Fentanyl was used for anesthesia, except in cases without i.v. route in which sevoflurane with nitrous oxide in oxygen was used for induction of anesthesia. FIO2 was adjusted using air and oxygen. The lower FIO2 was applied to the patients for a closure of ventricular septal defect, a reconstruction of coarctation or interrupted aortic arch, and pulmonary artery banding, while the higher FIO2 was used for systemic-to-pulmonary artery shunts and the repair of tetralogy of Fallot. In the congenital heart disease with the intracardiac shunt, the magnitude of the shunt flow and hemodynamics can be altered by changing systemic and pulmonary vascular resistance which could be induced by various ways. Since alveolar oxygen tension is a known determinant of pulmonary vascular resistance, an appropriate FIO2 should be applied to each patient with different pathophysiology. A low FIO2 should be set for the cases with nonrestrictive left-to-right shunting, since a high FIO2 may cause a torrential pulmonary blood flow. A high FIO2 is preferable for the cases with right-to-left shunting and a concomitant decreased pulmonary blood flow.

[Anesthetic management for emergency operation in seven patients with gunshot injury].

Seven patients with gunshot injury underwent emergency operations under general anesthesia. Trachea was intubated without muscle relaxants or after crash induction. Anesthesia was maintained with intravenous or volatile anesthetic agents titrated slowly. Four of seven patients fell into hypovolemic shock and were treated with aggressive intravenous volume replacement, vasopressors and catecholamines. Seven patients were given blood transfusion, of which the largest amount given was 17700 ml during the operation. Hemopneumothorax occurred in four patients, who needed intrathoracic drainage. Six patients survived and one died of multiple organ failure secondary to hypovolemic shock. The nature and severity of a bullet wound depend on the characteristics of the bullet (mass, construction, tendency to fragment or yaw, and velocity) and the tissue through which it has traveled. Therefore, the wound is often larger than expected, and the bullet may travel in an unexpected direction. Thus, it is important in anesthetic management of a patient with gunshot injury, to understand its mechanisms and evaluate the wound and to treat the patients in the same way as with other multiple trauma, especially taking care of hypovolemic shock.

[Anesthetic management for cesarean section in two parturients with quintuplet gestation].

Two parturients with quintuplet pregnancy underwent urgent or elective cesarean section under general anesthesia at 30 and 29 week gestational ages respectively. Since multiple gestation pregnancy requires enough medical staffs and instruments for preterm newborn resuscitation, emergency cesarean delivery was avoided. For cesarean delivery, the operation was started immediately after crash induction and intubation, and less than 1% isoflurane balanced with 60% nitrous oxide was used before birth in attempt to maintain uterine relaxation and sufficient utero-placental perfusion. After the delivery, aggressive maneuvers with PGE1 infusion, intravenous ergometrine and oxytocin, and interruption of volatile anesthetic inhalation (replaced by buprenorphine) were employed for decreasing the blood loss. The anesthesia and postoperative course of two patients and their babies were uneventful. Thus, anesthetic considerations may include; 1) high risk pregnancy related with huge pregnant uterus, 2) preterm labor, 3) preparation of sufficient man-power and instruments, 4) to avoid uterine contraction before delivery for fetal oxygenation, and 5) the puerperal promotion of uterine contraction to decrease blood loss.

[The anesthetic management of cesarean section for multiple pregnant patients].

Anesthetic management of cesarean section for twenty multiple pregnant patients, who were pregnant with triplet or quadruplet, was compared with that for 325 single pregnant patients and 21 twin pregnant patients. For anesthetic methods, spinal anesthesia was chosen most frequently in the multiple pregnant patients, as in single and twin (more than 75 percent). In multiple pregnant patients, the incidence of emergency operation was less. In multiple pregnant patients who received spinal anesthesia, gestational age was lower; birth weight was lighter; length of fundus uteri was longer; and blood loss including amniotic fluid was larger. In triplets, the third infants' UID-time was prolonged and their Apgar score was lower.

[Respiratory outcome in extremely premature infants following general anesthesia].

This study was aimed to predict the need of postoperative tracheal intubation in premature infants following anesthesia using volatile anesthetics by means of the scoring system derived from our former study of ketamine anesthesia. The subjects consisted of 14 infants (birth weight: 719 +/- 130 g and weight at operation 1882 +/- 312 g) needing cryotherapy for retinopathy and anesthetized with less than 1 MAC of volatile anesthetics. Respiratory outcome was successfully predicted in 9 patients (64%) while no infant was predicted incorrectly to be ready for tracheal extubation. The incidences of postoperative ventilatory support were 28% and 32% after anesthesia with volatile anesthetics and ketamine anesthesia, respectively. However, general anesthesia with volatile anesthetics appeared to be superior in actual outcome to ketamine anesthesia among the patients with high risk scores.

Duration of apnea in anesthetized infants and children required for desaturation of hemoglobin to 95%. The influence of upper respiratory infection.

Sixty-one patients ASA physical status 1-2 aged 1 month to 12 years undergoing elective surgery were included in the study. Anesthesia was induced via a mask with sevoflurane up to 5% and 66% nitrous oxide in oxygen. After paralysis with vecuronium (0.12 mg/kg iv), the trachea was intubated and the lungs were ventilated manually with 3% sevoflurane in oxygen until the end-tidal nitrous oxide decreased to less than 5%. Apnea was started by disconnecting the breathing circuit from the endotracheal tube. The time from the start of apnea to Spo2 of 95% was measured. Manual ventilation was reinstituted when Spo2 decreased to 95% and another set of vital signs was recorded. Twenty of 61 patients had symptoms of upper respiratory infection. The time to Spo2 of 95% correlated well with height, age, and body weight both by linear and non-linear regression analyses. The patients with symptomatic upper respiratory infection required less time for Spo2 to decrease to 95% compared to the asymptomatic children. We conclude that younger children require less time for Spo2 to decrease to 95%. The presence of upper respiratory infection is an additional factor increasing the susceptibility of small children to hypoxemia.

The effect of prostaglandin E1 on local cerebral blood flow during cerebral-aneurysm clip ligation.

Prostaglandin E1(PGE1) was administered for deliberate hypotension during general anaesthesia in 27 patients undergoing cerebral-aneurysm clip ligation, and the effect of the drug on local cerebral blood flow was studied. Local cerebral blood flow measurements were made using a thermal-gradient blood flowmeter. Control measurements were made immediately before administration of the drug. Local cerebral blood flow was measured 10, 30, 60 and 120 min after starting the drug infusion and 10, 30 and 60 min after discontinuation. The mean blood pressure was reduced significantly by the administration of PGE1. Urine output was increased after commencement of the drug infusion. Local cerebral blood flow did not change. These results suggest that PGE1 may be an appropriate hypotensive drug for use during cerebral-aneurysm clip ligation, because the cerebral blood flow remains within the normal range and the urine output is increased.