Increase in prominence of electrocardiographic J waves after a single dose of propofol in a patient with early ventricular repolarisation.

J waves appear on an electrocardiogram as an elevation of the J point in the terminal portion of the QRS complex. J waves are often benign, but may be associated with malignant ventricular arrhythmias. In some cases, such problems appear to have been precipitated by propofol infusions. We observed a sudden increase in J waves and profound hypotension following a single intravenous dose of propofol in an 84-year-old woman with early repolarisation in the inferior ventricular wall. When early repolarisation (as shown by electrocardiographic J waves) is observed in the inferior ventricular wall pre-operatively, patients should be carefully monitored. Myocardial ischaemia and the use of drugs that might worsen J waves should be avoided.

Anaesthesia for a patient with paraneoplastic limbic encephalitis with ovarian teratoma: relationship to anti-N-methyl-D-aspartate receptor antibodies.

Paraneoplastic limbic encephalitis associated with ovarian teratoma has recently been related to the development of antibodies to specific heteromers of the N-methyl-d-aspartate receptor and exhibits various manifestations including psychiatric symptoms, hypoventilation, seizures and derangement of autonomic nervous system function. Although recovery can sometimes occur spontaneously, early tumour resection with immunotherapy facilitates earlier recovery. Herein, we describe anaesthetic management of a 20-year-old woman who developed general convulsions and decreased level of consciousness, whom we suspected of having paraneoplastic limbic encephalitis and was scheduled for left ovarian tumour resection. Anaesthetic management was successful with no complications but the case acts as focus of discussion for the potential interaction of N-methyl-D-aspartate receptors and anaesthetic sensitivity.

Role of left atrial appendage in left atrial reservoir function as evaluated by left atrial appendage clamping during cardiac surgery.

We evaluated the role of left atrial appendage (LAA) in the left atrial (LA) reservoir function by assessing the changes in LA flow dynamics after LAA clamping during cardiac surgery. The subjects were 8 patients who had undergone coronary artery bypass grafting (CABG) and 7 who had undergone mitral valvular surgery due to mitral regurgitation. We recorded transmitral, pulmonary venous and LAA flow velocity patterns by intraoperative transesophageal pulsed Doppler echocardiography, monitoring LA pressure before and 5 minutes after LAA clamping. The maximal LAA area was significantly greater, and the peak late diastolic LAA emptying flow velocity was significantly lower before LAA clamping in the mitral regurgitation group than in the CABG group. In both groups, the peak early and late diastolic transmitral and pulmonary venous flow velocities significantly increased, and the peak second systolic pulmonary flow velocity significantly decreased during LAA clamping. There were no significant changes in heart rate and systemic systolic blood pressure during LAA clamping, whereas mean LA pressure and maximal LA dimension significantly increased in both the groups. The LA pressure-volume relation during ventricular systole shifted upward and to the left during LAA clamping, and the slope was steeper in the MR group than in the CABG group. We conclude that the LAA is more compliant than the LA main chamber, and plays an important role in LA reservoir function in the presence of LA pressure and/or volume overload.

Bronchospasm induced by cardiopulmonary bypass.

Severe bronchospasm during cardiopulmonary bypass (CPB) is an unusual event. A 16-year-old girl with pulmonary stenosis who underwent reconstruction of the right ventricle outflow tract experienced severe bronchospasm following CPB. Just after the initiation of the partial CPB, high inspiratory airway pressure was suddenly recognized. The lung had become too stiff for the anesthetic circuit bag to be squeezed by hand. Tracheobronchial obstruction was ruled out by investigation with a fiberoptic bronchoscope. A presumptive diagnosis of severe bronchospasm was made, and aggressive bronchodilator therapy was instituted. The attack was successfully treated with aggressive bronchodilator therapy. Although the exact causes for bronchospasm in our case are not clear, CPB factors, such as the release of complements and allergic reactions might have induced the attack under relatively light anesthetic state.

Transesophageal echocardiographic assessment of pulmonary arterial and venous flow during high-frequency jet ventilation.

STUDY OBJECTIVE: To evaluate high-frequency jet ventilation (HFJV) effects on pulmonary arterial and venous flow compared to those of intermittent positive-pressure ventilation (IPPV) by using pulsed Doppler transesophageal echocardiography. DESIGN: Prospective clinical study. SETTING: University-affiliated hospital operating room. PATIENTS: 13 ASA physical status I and II patients undergoing lower abdominal or lower extremity surgery. INTERVENTIONS: PATIENTS had total IV anesthesia with propofol and fentanyl. After anesthesia induction, a transesophageal echocardiography probe was inserted into the esophagus. IPPV (TV, 8-10 mL/kg; respiratory rate, 10-12 cycles/min; I/E ratio, 1:2; FIO(2), 1.0) and HFJV (driving pressure, 0.5-0.6 kgf/cm(2); frequency,3 Hz; I/E ratio, 1:1; FIO(2), 1.0) were performed under hemodynamically stable conditions. MEASUREMENTS: Pulmonary-arterial-flow velocity, pulmonary-venous-flow velocity, left ventricular short-axis view, and airway-pressure curve were recorded simultaneously. Parameters measured were: hemodynamic variables, arterial blood gases, inspiratory airway pressure; [from pulmonary-arterial-flow velocity] pre-ejection period (PEP), acceleration time (AT), right ventricular ejection time (RVET), and their ratios (PEP/AT, AT/RVET); [from pulmonary-venous-flow velocity] time-velocity integral of the first systolic wave (S1), second systolic wave (S2), and diastolic wave (D), and systolic fraction (integral S1 + S2/S1+ S2 + D); [from M-mode] left-ventricular-end systolic volume, left-ventricular-end diastolic volume (LVEDV), stroke volume, cardiac output, and ejection fraction, using Teichholz's method. MAIN RESULTS: Peak inspiratory airway pressure during HFJV was significantly lower than that during IPPV. HFJV significantly decreased PEP/AT, correlating positively with pulmonary arterial pressure, and significantly increased AT and AT/RVET, correlating negatively with pulmonary arterial pressure. Systolic fraction, correlating negatively with left atrial pressure, increased significantly during HFJV, as did LVEDV, stroke volume, cardiac output, and ejection fraction. CONCLUSIONS: Our results suggest that, in comparison to IPPV, HFJV significantly decreases pulmonary arterial pressure and left atrial pressure, resulting in significant increases in cardiac output and ejection fraction in healthy anesthetized adults.

[Effects of PGE1 on pulmonary arterial and venous flow in elderly patients--evaluation by transesophageal Doppler echocardiography].

Effects of PGE1 on pulmonary arterial and venous flow were evaluated noninvasively with transesophageal Doppler echocardiography in 13 elderly patients (70-79 years old), and the results were compared with those in control group of 13 patients (20-48 years old). In control group, infusion of PGE1 at a rate of 20 ng.kg-1.min-1 decreased pulmonary arterial pressure significantly, but not in elderly patients even at a rate of 50 ng.kg-1.min-1. In elderly patients, effects of PGE1 were more remarkable for afterload reduction than preload, so that cardiac output was maintained without change in stroke volume and heart rate, but with increase of heart rate in control patients. From our results, it is concluded that PGE1 may have less effect on pulmonary hemodynamics in elderly patients.

[Effects of sevoflurane, isoflurane, and halothane on regional myocardial blood flow in the ischemic canine heart].

The effects of sevoflurane (Sev), isoflurane (Iso), and halothane (Hal) on coronary circulation were studied in 30 dogs with acute coronary arterial stenosis. Regional myocardial blood flow (rMBF) was measured by hydrogen clearance method. There was no significant difference between each anesthetic agent in heart rate, mean arterial pressure, and cardiac output under any anesthesia level. As the inspired concentration of each anesthetic is increased, rMBF decreased significantly and rMBF/rate-pressure-product (RPP) ratio increased in normal area. In Sev and Iso groups, rMBF/RPP ratios were higher than that in Hal group, suggesting luxury perfusion caused by Sev and Iso. In the ischemic area, rMBF was reduced depending on the inspired concentration of each anesthetic agent and transmural maldistribution of blood flow was not observed with any anesthetic agent. Nevertheless the ratio of rMBF in ischemic area to that of normal area was decreased in Sev and Iso groups, but not in Hal group. In this study, neither Sev nor Iso worsened regional myocardial ischemia. However, Sev-induced coronary vasodilation may cause regional myocardial ischemia by redistribution of flow under steal prone condition.

[Hemodynamic effects of dobutamine, dopamine and methoxamine during thoracic epidural anesthesia in dogs with coronary stenosis].

Dobutamine (DOB), dopamine (DOP) and methoxamine (MEX) were compared as to their effectiveness in controlling circulatory depression caused by thoracic epidural anesthesia in dogs with instituted coronary stenosis. DOB appeared to best serve the purpose of reestablishing systemic circulation, notably with an elevation of blood pressure. DOP achieved the best restoration of the absolute value of regional myocardial blood flow (RMBF), but DOB and DOP both caused RMBF in stenosed and non-stenosed areas to increase to virtually the same extent, and furthermore, worsened the intramyocardial distribution of RMBF in stenosed area. With MEX, an alpha-stimulant, there was noted a significant increase in blood flow through a stenosed area and, moreover, the increment tended to be greater than in a non-stenosed area, a fact suggesting involvement of such a mechanism as reverse coronary steal.

[Effects of sevoflurane on left ventricular diastolic function using transesophageal echocardiography].

The effects of sevoflurane on left ventricular diastolic filling were evaluated using transesophageal Doppler echocardiography in 10 normal subjects. The time-velocity integral of early filling decreased significantly with sevoflurane 1 MAC (7.73 +/- 2.05 to 6.82 +/- 1.90 cm), suggesting impaired left ventricular relaxation. Abnormal left ventricular relaxation results in compensatory increment of peak velocity and time-velocity integral during atrial filling, both of which were significantly decreased by sevoflurane in this study (35.5 +/- 6.6 to 29.1 +/- 4.8 cm.sec-1, 3.22 +/- 0.65 to 2.73 +/- 0.67 cm, respectively). Although the ratio of early peak velocity to late filling velocity was unchanged, it appears that left ventricular diastolic function including active relaxation, passive compliance, atrial contraction, and elastic recoil was impaired by sevoflurane 1 MAC.

[Bronchospasm during anesthesia in a patient with Prader-Willi syndrome].

A patient with Prader-Willi syndrome developed bronchospasm during anesthesia. The patient was a 9-year-old boy and was scheduled for orchiopexy. His psychomotor development was delayed, and at 12 months of age he was diagnosed as Prader-Willi syndrome by chromosomal examination. The patient weighed 17 kg, was 111 cm tall, and had no symptom of upper respiratory infection preoperatively. Preoperative examinations were normal except supraventricular extrasystole in electrocardiogram. Following administration of scopolamine 0.15 mg intramuscularly as preanesthetic medication, anesthesia was induced smoothly by slow induction using N2O-O2-sevoflurane. However, right after endotracheal intubation with vecuronium 2 mg, remarkable stridor was noticed. Despite hyperventilation, the patient exhibited hypercapnia, and the diagnosis of bronchospasm was made. Aminophylline and steroid were administered intravenously and halothane was inhaled instead of sevoflurane. The bronchospasm was improved gradually and surgery was finished. Prader-Willi syndrome is an uncommon disease first reported by Prader in 1956 and characterized by hypotonia, hypomentia, hypogonadism and obesity. In the perioperative management for a patient with Prader-Willi syndrome, special attention must be paid to the abnormalities in the upper and lower respiratory systems.

[Hypoxemia during cesarean section--evaluation of venous air embolism by transesophageal echocardiography].

We studied the incidence and cause of hypoxemia during Cesarean section under general anesthesia. Arterial oxygen desaturation (< or = 95%) occurred in 6 of 28 patients (21%). Venous air embolism (VAE) was detected in 7 of 28 subjects (25%), but the severity of which was mild and was not associated with oxygen desaturation. While, there were significant differences in obesity index, preoperative respiratory function, and PaO2 after the induction of anesthesia between the patients with and without oxygen desaturation. Our results suggest that hypoxemia may occur frequently during Cesarean section under general anesthesia, but is not caused by VAE, and is related with the physiological changes associated with pregnancy.

[Is thoracic epidural anesthesia beneficial to myocardial ischemia?--Influence of hemodynamics].

The effects of thoracic epidural anesthesia (TEA) on regional myocardial blood flow (RMBF) and hemodynamics were evaluated in open-chest dogs with coronary artery stenosis. In the 6 dogs with pressure-rate quotients (PRQ) of greater than 0.8, TEA caused a significant increase of the ratio of endocardial to epicardial RMBF in the ischemic region and tended to increase the ratio of RMBF in the ischemic to normal area, resulting in improved myocardial ischemia. There was no reduction of myocardial ischemia in the 11 dogs with PRQ of less than 0.8. The hemodynamic effects determine whether TEA is favorable for the ischemic heart or not. It appears that PRQ is useful as an indicator of myocardial oxygen balance during TEA.

[The effects of low dose clonidine on perioperative hemodynamics and anesthetic requirements in elderly patients].

The effects of clonidine, alpha 2-adrenergic receptor agonist, on perioperative hemodynamics and anesthetic requirements were studied in randomized 20 elderly patients without hypertension (ASA I-II) scheduled for elective abdominal surgery under general anesthesia. The control group (n = 10) was premedicated with oral diazepam 0.1 mg.kg-1 90 min prior to arrival in the operating room. The clonidine group (n = 10), in addition, received clonidine approximately 2.5 micrograms.kg-1 orally at the same time. Anesthesia was induced with fentanyl 2 micrograms.kg-1 and thiamylal 4 mg.kg-1. Vecuronium 0.15 mg.kg-1 following 0.01 mg.kg-1 priming dose was used to facilitate endotracheal intubation. Anesthesia was maintained with isoflurane in 50% nitrous oxide-oxygen and supplementary fentanyl. Clonidine effectively attenuated the cardiovascular response associated with laryngoscopy and tracheal intubation. Intraoperative variability of heart rate was significantly lower in patients receiving clonidine compared with controls. No significant differences in the requirements of either isoflurane or narcotic supplementation were observed between the two groups. We conclude that a low dose clonidine is a useful adjunct in the management of elderly patients without producing side effects.

[Blood coagulation-fibrinolysis system during transurethral resection evaluated by thrombelastography].

Intraoperative changes in blood coagulation-fibrinolysis system were evaluated in 21 patients under epidural anesthesia by thrombelastography. Ten patients received transurethral resection of prostate (TUR-P) and 11 patients received transurethral resection of bladder tumor (TUR-Bt). Thrombelastographic variables: reaction time (R), coagulation time (K), maximum amplitude (MA), and amplitude 60 min after MA (A 60) were measured. The coagulability was evaluated by R + K, the absolute strength of clot by MA, and fibrinolysis using MA-A60. There was no significant change of these indices in TUR-Bt group. On the other hand, in TUR-P group, R + K was significantly shortened and MA-A60 had a tendency to increase it, but MA caused no change. Resected prostatic weight correlated significantly with the decrease of MA, and had a tendency to correlate with the increase of MA-A60 in TUR-P group. Both coagulation and fibrinolysis were activated in TUR-P group. When the resected prostatic weight is large, the risk of coagulopathy may increase.

[Changes of arterial blood pressure and heart rate during induction of anesthesia with propofol--efficacy of propofol titration using bispectral index as an indicator].

Bispectral index (BIS) is a processed EEG parameter that measures the hypnotic effects of anesthetic and sedative agents on the brain. We studied whether propofol titration using BIS allows us to prevent hemodynamic changes during induction of anesthesia and endotracheal intubation. Thirty patients without hypertension and obesity were studied. In the titration group (n = 15), BIS was maintained at 40 during induction of anesthesia with propofol. In the bolus group, anesthesia was induced with a bolus infusion of propofol 2 mg.kg-1 (n = 15). Arterial blood pressure and heart rate were recorded before induction of anesthesia, during induction of anesthesia, immediately after, and 1 min, 2 min, and 3 min after intubation. Diastolic blood pressure and heart rate increased significantly after endotracheal intubation in both groups. Systolic blood pressure significantly increased immediately after intubation in the bolus group, but was unchanged in the titration group. These results suggest that BIS is useful to prevent significant increases in systolic blood pressure associated with endotracheal intubation during induction of anesthesia with propofol.

[Isoflurane and sevoflurane impair left ventricular relaxation in dogs with fixed heart rate].

The effects of isoflurane (Iso) and sevoflurane (Sev) on left ventricular relaxation were evaluated in 22 open-chest dogs with fixed heart rate (130 beats.min-1) using atrial pacing. Fentanyl was injected intravenously to maintain anesthesia during the preliminary preparation. In both Iso and Sev groups (n = 11), left ventricular systolic pressure, mean aortic pressure and dp/dt max were significantly decreased at 0.5 MAC, but there was no significant change in left ventricular end-diastolic pressure. Left ventricular systolic function was depressed to the similar extent in both groups. In Sev group, -dp/dt max and time constant of isovolumic left ventricular pressure fall (T) increased significantly at 0.5 MAC but it increased at 1.5 MAC in Iso group. T at 0.5 MAC Sev was also significantly longer compared with T at equipotent Iso. These findings suggest that Sev may impair isovolumic left ventricular relaxation more strongly than Iso, and this may result from the difference of the effect of each agent on intracellular Ca2+ homeostasis in the myocardium.

[Left ventricular function during hypoxia. 1: Effect of blood glucose level].

We investigated the effects of blood glucose levels and myocardial glucose uptake on cardiac function during hypoxia in mongrel dogs (N = 50). During hypoxia (PaO2 = 20 mmHg) caused by inhalation of low concentration of oxygen for 2 hours, left ventricular (LV) function including LV pressure, maximum rate of rise of LV pressure, and cardiac index decreased significantly following initial enhancement. There were significant correlations between these hemodynamic parameters and blood glucose levels. The blood glucose levels correlated significantly with myocardial glucose uptake and blood lactic acid levels (r = 0.660: P = 0.000, r = 0.380: P = 0.000, respectively). Eight of nine dogs which died within 90 minutes during hypoxia showed low blood glucose levels and high lactic acid levels. During hypoxia, myocardial glucose uptake increased to more than five times of control value. On the other hand myocardial lactic acid uptake decreased and turned to production. At the same degree of blood lactic acid levels, LV function was maintained better with high blood glucose levels than with low levels. With low blood glucose levels, myocardial lactic acid uptake and production tended to cease. The pronounced change in LV function during hypoxia could be partially explained by decreased production of ATP due to decrease in myocardial glucose uptake and high lactic acid levels. It seems that high blood glucose levels are preferable to maintain cardiac performance under such a condition.

[Effects of diltiazem hydrochloride on blood gases].

The effects of diltiazem, Ca ion channel blocker, on arterial blood gases were evaluated in 50 patients (G-I: 24 patients undergoing abdominal surgery, G-II: 26 patients undergoing non-abdominal surgery). Diltiazem hydrochloride was administered to prevent intraoperative hypertension as a bolus (5 mg) followed by a continuous infusion (5-10 micrograms.kg-1.min-1). Arterial blood gases were analyzed just before, as well as 5 and 15 min after the administration of diltiazem. In G-I, arterial blood oxygen tension decreased significantly (P < 0.001) from 210.8 +/- 42.4 to 197.7 +/- 50.2 mmHg 5 min after infusion, and to 193.2 +/- 53.4 mmHg 15 min after; while there was no significant difference in G-II. Diltiazem infusion may deteriorate oxygenation in patients undergoing abdominal surgery, and therefore oxygenation should be carefully monitored.

[Severe hypoxemia during cesarean section].

We describe three cases in which severe hypoxemia occurred during cesarean section. The first and second patients showed low oxygen saturation (91, 90%, respectively) on their arrival at the operation room, and hypoxemia deteriorated rapidly after the induction of anesthesia. During surgery low oxygen saturation, ranging from 90 to 95%, persisted until the beginning of spontaneous respiration. In the third patient, oxygen saturation fell suddenly to 93% after the delivery of a neonate, and the arterial blood gas analysis revealed Pao2 68.5 mmHg with 38% oxygen. Hypoxemia was transient and resolved at the end of operation. Parturients have been reported to be likely to develop hypoxemia physiologically. Apnea for a short interval during tracheal intubation may cause severe hypoxemia in parturients compared with normal subjects. Ritodrine, a beta 2 stimulator, which was administered in the first and second patients just prior to operation, may be one of the factors leading to hypoxemia because of its inhibition of hypoxic pulmonary vasoconstriction. Venous air embolism (VAE) may occur frequently during cesarean section, especially during repair of the uterus. VAE may have caused hypoxemia in the third patient. In conclusion, parturients should be monitored carefully with pulse oximetry during cesarean section.