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平成17年の4週間に群馬大学医学部附属病院で行われた全身麻酔予定手術222例における麻酔関連薬物破棄量を検討した. 麻酔方法は, 患者の年齢等を考慮しながらプロポフォール1～2mg/kg, ベクロニウム0.1mg/kgで導入し, 亜酸化窒素4l/分-酸素2l/分-セボフルランでの麻酔維持を基本とした. 麻酔導入時の血行動態の変動に対しての各種薬物使用は各担当麻酔科医の判断とした. 心臓・血管外科手術の麻酔方法は, ミダゾラム0.1mg/kg, フェンタニル10μg/kg, ベクロニウム0.1mg/kgで導入し, プロポフォール4～6mg/kg, セボフルラン0.5～1.0%とフェンタニルの間欠投与で維持し, フェンタニルの使用量は最高20μg/kgまでとした．222例の注射器の平均使用本数は8.8±8.5本, 全破棄した薬物の金額は142±343円, 一部破棄した薬物の金額は954±876円であった. プロポフォールは222例中169例で破棄があり, 平均残量は88±48mg, ベクロニウムは222例中162例で破棄があり, 平均残量は4.5±2.8mg, エフェドリンは222例中156例で破棄があり, 平均残量は34±7mgであった. プロポフォール, ベクロニウム, エフェドリンは7割以上の症例で破棄されていた. 麻酔科医は使用しなかった麻酔関連薬物量およびその金額を正確に把握し, それらの量や金額を減らすことに注意することも肝要であると思われる.

Background and Purpose— The purpose of this study was to examine the effects of diabetes mellitus and its severity on the cerebral vasodilatory response to hypercapnia. Methods— Thirty diabetic patients consecutively scheduled for elective major surgery were studied. After induction of anesthesia, a 2.5-MHz pulsed transcranial Doppler probe was attached to the patient’s head at the right temporal window, and mean blood flow velocity of the middle cerebral artery (Vmca) was measured continuously. After the baseline Vmca, arterial blood gases, and cardiovascular hemodynamic values were measured, end-tidal CO 2 was increased by reducing ventilatory frequency by 2 to 5 breaths per minute. Measurements were repeated when end-tidal CO 2 increased and remained stable for 5 to 10 minutes. Results— Significant differences were observed in absolute and relative CO 2 reactivity between the diabetes and control groups (absolute CO 2 reactivity: control, 2.8±0.7; diabetes mellitus, 2.1±1.3; P 2 reactivity: control, 6.3±1.4; diabetes mellitus, 4.5±2.7; P U test). Significant differences were also found between diabetic patients with retinopathy and those without retinopathy in absolute ( P =0.002) and relative ( P =0.002) CO 2 reactivity, glycosylated hemoglobin ( P =0.0034), and fasting blood sugar ( P =0.01) (Scheffé’s test, Mann-Whitney U test). There was an inverse correlation between absolute CO 2 reactivity and glycosylated hemoglobin ( r =0.69, P Conclusions— Insulin-dependent diabetic patients have an impaired vasodilatory response to hypercapnia compared with that of the control group, and the present findings suggest that their degree of impairment is related to the severity of diabetes mellitus.

Adrenomedullin is a potent vasodilatory peptide. Plasma adrenomedullin (AM) concentrations increase during and after cardiopulmonary bypass (CPB). However, the cause of this increase and its site of production have not been identified. We investigated the role of the hepatosplanchnic and cerebral circulations in the increase of plasma AM and investigated whether tissue hypoxygenation is a cause of the AM increase seen during CPB. We measured plasma total AM (AM-T) and the biologically active form of AM, mature AM (AM-m), in seven patients undergoing CPB. Both plasma AM-T and AM-m concentrations increased significantly 60 min after weaning from CPB. At this time point, arterial AM-T and AM-m concentrations were 18-fold and 10-fold larger, respectively, than baseline values measured after the induction of anesthesia. The plasma AM-m concentration and the ratio of AM-m/AM-T in blood from the hepatic vein were significantly larger than those from the radial artery or jugular bulb. The AM-m/AM-T ratio decreased during CPB, suggesting that production of the intermediate form of AM, AM-glycine, is more than that of AM-m. The oxygen tension of the hepatic venous blood (PhvO2) was significantly less during CPB. Plasma AM-m concentrations sampled from the hepatic vein showed a significant negative correlation with PhvO2 at 10 min (r = 0.824; P < 0.02) and 60 min (r = 0.828; P < 0.02) after the onset of CPB. These data suggest that the hepatosplanchnic circulation is an important source of AM-m during CPB. Furthermore, hypoxygenation of the hepatosplanchnic region may be an important cause of this AM-m increase.

A 65-year-old female patient underwent surgery to clip a giant basilar artery aneurysm with closed-chest extracorporeal circulation using femorofemoral bypass. Moderate hypothermia (27 degrees C-30 degrees C), retention of spontaneous circulation, and propofol infusion (3-5 mg. kg(-1). h(-1)) were used under general anesthesia. Blood outflow via femoral vein was sufficient to maintain cardiopulmonary bypass and to induce hypothermia. Hemodynamics were controlled with dopamine and noradrenaline. In this case, extracorporeal circulation under moderate hypothermia was used to assist rather than substitute for spontaneous circulation, and spontaneous circulation was maintained at all times. We think that this method had advantages over deep hypothermic circulatory arrest with regard to intraoperative risks and postoperative complications.

BACKGROUND There have been many studies regarding the etiology of postoperative cognitive dysfunction after coronary artery bypass graft (CABG) surgery. Although its etiology remains unresolved, one possible factor related to postoperative cognitive dysfunction is a reduced internal jugular venous oxygen hemoglobin saturation (SjvO2) during the rewarming period. The purpose of this study was to examine the effect of rewarming rates on SjvO2 during rewarming. METHODS One-hundred patients scheduled for elective CABG surgery were randomly divided into two groups; control group (0.48 +/- 0.09 degrees C, n = 50), slow rewarming group (0.24 +/- 0.09 degrees C, n = 50). After the induction of anesthesia, a fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to monitor SjvO2 continuously. Hemodynamic parameters, arterial and jugular venous blood gases were measured at nine time-points. RESULTS Cerebral desaturation (defined as a SjvO2 value below 50%) during rewarming was more frequent in the control group than in the slow group. Cerebral desaturation time (duration when SjvO2 was less than 50%) and the ratio of the cerebral desaturation time to the total CPB time in the control group differed significantly from those in the slow group (control group: 17 +/- 11 min, 12 +/- 4%, slow group: 10 +/- 8 min, 7 +/- 4%, respectively, P < 0.05). There was no significant difference in mini-mental state examination on the day before the operation nor at 1 month after the surgery among four values (the day before the operation: control group; 48 +/- 8, slow group; 48 +/- 7, at one month after the surgery: control group; 46 +/- 7, slow group; 45 +/- 9). CONCLUSIONS A slow rewarming rate could reduce the chance of a decrease in SjvO2 during rewarming.

Background. One of the key mechanisms leading to β-adrenergic receptor-specific desensitization is the phosphorylation of agonist-occupied receptors by the specific β-adrenergic receptor kinase (GRK2). The present study examines whether GRK2 is altered during septic shock in rats. Materials and methods. Male Wistar rats (7 weeks) weighing between 250 and 300 g were anesthetized with pentobarbital (10 mg/kg ip). Escherichia coli endotoxin (10 mg/kg in 0.3 mL of saline) or saline (0.3 ml) was injected intravenously via the dorsal vein. Hemodynamic parameters and humoral mediators were measured at 2 h after the administration of endotoxin. The hearts were immediately excised to examine β-adrenergic receptor density and GRK2 level. We also studied the inotropic response to isoproterenol at the same time in other animals. Results. Myocardial β-adrenergic receptor density in the membrane fraction was decreased after an intravenous administration of 10 mg/kg LPS (LPS group: baseline value; 82 ± 11 fmol/mg protein; 120 min after LPS; 58 ± 11 fmol/mg protein, P < 0.05). GRK2 levels in the membrane and cytosolic fraction of the control group did not change. In the LPS group, GRK2 levels in the membrane fraction were increased at 60 and 120 min after the treatment (60 min; control, 4.5 ± 0.4; pithed control, 4.4 ± 0.6; LPS group, 6.2 ± 0.3; pithed LPS group, 5.5 ± 0.4; 120 min: control, 4.4 ± 0.3; pithed control, 4.9 ± 0.7; LPS group, 7.1 ± 0.3; pithed LPS group, 5.9 ± 0.4; densitometric unit, respectively: P < 0.05). Conclusions. GRK2 levels in the membrane fraction are increased during septic shock in rats. GRK2 might play a role in the impairment of the β-adrenergic receptor signal transduction system.

Background The authors hypothesized that patients with cerebrovascular abnormalities or metabolic disorders may experience abnormality in cerebral circulation more frequently than patients without these risks. The current study attempted to assess jugular venous bulb oxygen saturation (SjvO2) in patients with preexisting diabetes mellitus or stroke undergoing normothermic cardiopulmonary bypass. Methods Thirty-nine patients undergoing elective coronary artery bypass graft surgery were studied, including 19 age-matched control patients, 10 diabetic patients, and 9 patients with preexisting stroke A 4.0-French fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to continuously monitor internal SjvO2. Hemodynamic parameters and arterial and jugular venous blood gases were measured at seven time points: (1) after the induction of anesthesia and before the start of surgery, (2) just after the beginning of cardiopulmonary bypass, (3) 20 min after the beginning of bypass, (4) 40 min after the beginning of bypass, (5) 60 min after the beginning of bypass, (6) just after the cessation of bypass, and (7) at the end of the operation. Results No significant differences were seen in mean arterial pressure, arterial carbon dioxide tension (PaCO2), or hemoglobin concentration among the three groups during the study. The SjvO2 value did not differ among the three groups after anesthesia induction and before surgery, just after the beginning of cardiopulmonary bypass, 60 min after the beginning of bypass, just after the end of bypass, or at the end of the operation. Significant differences between the control group and the diabetic and stroke groups were observed, however, at 20 min and 40 min after the beginning of bypass (at 20 min: control group 62.2 +/- 6.8%, diabetes group 48.4 +/- 5.1%, stroke group 45.9 +/- 6.3%; at 40 min: control group 62.6 +/- 5.2%, diabetes group 47.1 +/- 5.2%, stroke group 48.8 +/- 4.1% [values expressed as the mean +/- SD]; P < 0.05). Also, values in the diabetes and stroke groups were decreased at 20 min and 40 min after the beginning of bypass compared with before the start of surgery. Conclusions A reduced SjvO2 value was observed more frequently in patients with preexisting diabetes mellitus or stroke during normothermic cardiopulmonary bypass. It is possible that cerebral circulation during normothermic bypass is altered in patients with risk factors for cerebrovascular disorder.

Background . In this study, we assessed the effects of normothermia and hypothermia during cardiopulmonary bypass (CPB) both on internal jugular venous oxygen saturation (SjvO 2 ) and the regional cerebral oxygenation state (rSO 2 ) estimated by near infrared spectroscopy (NIRS). Methods . Thirty patients scheduled for elective coronary artery bypass graft surgery (CABG) were randomly divided into two groups. Group 1 (n = 15) underwent surgery for normothermic (> 35°C) CPB, and group 2 (n = 15) underwent surgery for hypothermic (30°C) CPB, and alpha-stat regulation was applied. A 4.0-French fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to continuously monitor the SjvO 2 value. To estimate the rSO 2 state, a spectrophotometer probe was attached to the mid-forehead. SjvO 2 and rSO 2 values were then collected simultaneously using a computer. Results . Neither the cerebral desaturation time (duration during SjvO 2 value below 50%), nor the ratio of the cerebral desaturation time to the total CPB time significantly differed (normothermic group: 18 ± 6 min, 15 ± 6%; hypothermic group: 17 ± 6 min, 13 ± 6%, respectively). The rSO 2 value in the normothermic group decreased during the CPB period compared with the pre-CPB period. The rSO 2 value in the hypothermic group did not change throughout the perioperative period. Conclusions . These findings suggest that near infrared spectroscopy might be sensitive enough to detect subtle changes in regional cerebral oxygenation.

We report here a case of Staphylococcus epidermidis endocarditis with bacterial vegetation which was suspected by intraoperative alternating pulse on arterial pressure monitoring. A 65-year-old man was diagnosed as lumbar spinal canal stenosis and scheduled for operation. Preoperatively, he had chronic renal failure, mild aortic valve stenosis, and moderate mitral valve regurgitation. Neither inflammatory signs nor vegetations on TEE were observed preoperatively. General anesthesia was induced with propofol and vecuronium, and maintained with oxygen (33%), nitrous oxide and sevoflurane. Two hours after the beginning of operation, alternating pulse was observed suddenly on arterial pressure waves without marked change in hemodynamic parameters. The operation was performed uneventfully and alternating pulse disappeared after changing from prone position to supine. Using a transesophageal echocardiography, large-sized bacterial vegetation (22 x 17 mm) was found in the left ventricle. Second operation was performed to remove vegetation at three weeks after first operation. Alternating pulse is generally considered as a sign of severe left ventricular dysfunction such as dilated cardiomyopathy and aortic stenosis. Therefore, we should be careful about pulse disorder during operation for the patient who is in the state of severe heart failure.

The purpose of this study was to examine the effects of a small dose of prostaglandin E1 on systemic and cerebral oxygenation. Thirty patients for coronary artery bypass graft surgery were randomly divided into two groups: Group 1 received PGE1 25 ng.kg-1.min-1. Group 2 received PGE1 50 ng.kg-1.min-1. After measuring baseline hemodynamics and mixed (SvO2) and juglar (SjvO2) venous oxygen saturations, administration of PGE1 at a rate of 25 ng.kg-1.min-1 or 50 ng.kg-1.min-1 was started before and during CPB. In group 2, mean arterial pressure (MAP) decreased during CPB, while in group 1, MAP was unchanged during CPB. There was no change in SjvO2 both in group 1 and group 2 before and during CPB. The administration of PGE1 at a rate of 25 ng.kg-1.min-1 during CPB was suitable for the maintenance of SvO2 and SjvO2.

To evaluate the cerebral oxygenation effects of hypotension induced by prostaglandin E1 (PGE1) during fentanyl-oxygen anaesthesia.Ten patients who underwent elective cardiac surgery received infusion of PGE1. After measuring the baseline arterial, mixed venous and internal jugular vein blood gases, systemic haemodynamics, and regional cerebral oxygen saturation (rSO2) estimated by INVOS 3100R, PGE1 was continuously infused at 0.25-0.65 microgram.kg-1.min-1 (mean dosage: 410 +/- 41.4 mg.kg-1.min-1) intravenously. Ten, 20 and 30 minutes after the start of drug infusions, blood gases described above were obtained simultaneously with the measurement of systemic haemodynamics and rSO2. Thirty minutes from the start of drug infusions, administration of PGE1 was stopped. The same parameters were measured again 10, 30 minutes after the stop of drug infusion.PGE1 decreased mean arterial pressure (MAP) to approximately 70% of the baseline value (P0.05). PGE1 increased mixed venous saturation, but in contrast did not affect internal jugular pressure, internal jugular oxygen saturation and rSO2.These results suggest that PGE1 is a suitable drug for induced hypotension because flow/metabolism coupling of brain and regional cerebral oxygenation were well maintained during hypotension.

Background: Whether pulsatile flow offers substantial advantages for brain protection during cardiopulmonary bypass is controversial. The purpose of this study is to determine whether differences exist between pulsatile and nonpulsatile bypass concerning the effects on internal jugular venous saturation and on the state of regional cerebral oxygenation during normothermia. Methods: Twenty-two patients undergoing elective coronary artery bypass grafting were randomly divided into 2 groups: group 1 (n = 11) received nonpulsatile perfusion during cardiopulmonary bypass and group 2 (n = 11) received pulsatile perfusion during bypass. We used an intra-aortic balloon pump to generate pulsatility. A spectrophotometric probe (INVOS 3100R, Somanetics, Troy, Mich) was used to assess the state of regional cerebral oxygenation. A 4F fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to monitor jugular venous oxygen saturation. Hemodynamic variables, arterial and jugular venous blood gases, and regional cerebral oxygenation were measured at 7 times points. Results: In both groups, jugular venous oxygen saturation decreased at the early stage of the cardiopulmonary bypass ( P = .03). Five patients in group 1 and 6 in group 2 had a jugular venous oxygen saturation of less than 50%. In both groups, the regional cerebral oxygenation value decreased during cardiopulmonary bypass ( P = .04). Conclusions: The present results showed that pulsatility generated through the use of intra-aortic balloon pumping did not produce any beneficial effects on jugular venous oxygen saturation and regional cerebral oxygenation at normothermia. (J Thorac Cardiovasc Surg 1999;118:361-6)