[Anesthetic management of a patient with hypertrophic obstructive cardiomyopathy under epidural anesthesia with high dose fentanyl]

Hypertrophic obstructive cardiomyopathy (HOCM) is characterized by asymmetric hypertrophy of the intraventricular septum, causing intermittent obstruction of the left ventricular outflow tract. General principles of management for HOCM include maintenance of adequate preload and afterload, and avoidance of tachycardia and increased myocardial contractility. A 57 year old male for subtotal gastrectomy and gastrojejunostomy received epidural anesthesia with epidural high dose fentanyl (0.5 mg) and 0.5% isoflurane with N2O and oxygen. Blood pressure and heart rate decreased mildly but were stable during the operation and during the recovery period from anesthesia without any complaints of pain. The results suggest that epidural high dose fentanyl anesthesia is a good method for patients with HOCM.

Effects of thiopental and ketamine on cardiac function during moderate hemorrhage in chronically instrumented rats

This study was designed to assess the effects of thiopental and ketamine on cardiac function after a blood loss of 2 ml/100 g of body weight. In nine Sprague-Dawley rats, a catheter was placed in the abdominal aorta, a pulsed Doppler probe was positioned around the thoracic aorta, and a wall-thickness probe was sutured onto the left ventricle. On three occasions, all rats were studied awake, during thiopental anesthesia, and during ketamine anesthesia. In awake rats, a 30% blood loss resulted in an immediate, transient hypotension (49%) and a prolonged decrease in cardiac output (39%) and stroke volume (28%). No significant changes were observed in the wall-thickening fraction, which is an index of cardiac contractility, and in the heart rate. The effect of thiopental on cardiovascular responses to moderate hemorrhage was minimal. Although ketamine did not affect the hypotensive response to moderate hemorrhage, it did accentuate systemic vasoconstriction and cardiac depression as indicated by a decrease in cardiac output (57%), stroke volume (49%), and wall thickness (47%).

Is pentobarbital appropriate for basal anesthesia in the working rat heart model?

In the present study we have examined the effects of the general anesthetic agents for the excision of the heart on the hemodynamic function of the ischemic perfused heart. Animals were divided into three groups. In one group rats were anesthetized with sodium pentobarbital intraperitoneally. Animals of the second and third groups were anesthetized with inhalation anesthetics, sevoflurane and isoflurane, respectively. The hearts were then rapidly excised and perfused by a working heart model. After control perfusion, whole-heart ischemia was induced by one-way aortic valve for 15 min followed by reperfusion for 30 min. During preischemic control period, cardiac output (CO) and left ventricular dP/dT maximum (LV dP/dT max) in the isoflurane group were significantly higher than those in the pentobarbital group. During reperfusion, CO and LV dP/dT max in the isoflurane and sevoflurane groups recovered more rapidly than those in the pentobarbital group. Although there were no significant differences in myocardial ATP and glycogen levels among the groups, myocardial lactate in the pentobarbital group was significantly higher than those in the sevoflurane and isoflurane groups. These results suggest that intraperitoneal pentobarbital anesthesia, administered prior to heart excision, may affect the performance of the ischemic perfused heart thereafter. Therefore, we would suggest that isolation of hearts by means of inhalation anesthesia is better than by means of pentobarbital in the working rat heart.

Effects of propafenone on function and metabolism in the ischemic working rat heart

We examined the effects of propafenone, a new anti-dysrhythmic agent, on myocardial function and metabolism in ischemic working rat heart preparations. In the treated hearts, propafenone, 0.3 micrograms/ml and 3 micrograms/ml, were added to Krebs-Henseleit bicarbonate buffer perfusate throughout the experiments. Whole heart ischemia was induced through a one-way aortic valve for 15 min followed by 'reperfusion for 30 min. After induction of ischemia, the cardiac output, peak aortic systolic pressure, left ventricular dP/dtmax, and myocardial ATP concentration were greater in the treated hearts than in the untreated ones. All hearts in the untreated group developed ventricular fibrillation (Vf) at the beginning of the reperfusion period. On the other hand, no treated hearts had Vf at any time during the experiment. However, propafenone, 3 micrograms/ml, evoked a negative inotropic effect before and after ischemia. These results indicate that propafenone may contribute to early recovery from ischemia in myocardial function and metabolism, although it has a negative inotropic action.

Anesthetic influences on myocardial and hepatic energy metabolism in hemorrhaged spontaneous hypertensive rats

Twenty four spontaneously hypertensive rats (SHRs) were used to assess the influence of anesthetics on myocardial and hepatic energy metabolism after hemorrhage. They were divided into four groups: a control group and three others which received pentobarbital (60 mg.kg-1 ip), 2.2% enflurane, or 1.4% isoflurane. Following a 10-min stabilisation period, blood (2 ml.100 g body weight-1) was gradually withdrawn over a 5-min period from a femoral artery. Thirty minutes after the induction of hemorrhage, the heart and liver were removed, and myocardial and hepatic metabolites (ATP, lactate, pyruvate, and glycogen) were measured by the enzymatic methods. Metabolic acidosis and decreased hematocrit were noted in all groups after hemorrhage. The mean arterial pressure in rats receiving anesthetics decreased significantly in comparison with the control group. There were significant increases of myocardial and hepatic lactate/pyruvate ratios in rats receiving enflurane when compared with controls. These results suggest that enflurane may be more detrimental than other anesthetics to the maintenance of anesthesia in hypovolemic SHRs.

Effects of prostacyclin analogue, OP-2507, on function and metabolism in the ischemic working rat heart

We examined the effects of a new stable prostacyclin analogue, OP-2507, on myocardial function and metabolism in the ischemic working rat heart preparation. The hearts were perfused with Krebs-Henseleit bicarbonate (KHB) buffer, and whole heart ischemia was induced by one-way aortic valve for 15 min follows by reperfusion for 30 min. In the treated hearts, OP-2507, 20 ng.ml(-1), was administered to KHB buffer from the beginning to the end of experiment. During ischemia, coronary flow in the OP-2507 group increased significantly more than that in the control group. The mechanical performance of both groups was impaired after ischemia. However, the recovery of coronary flow, cardiac output, peak systolic pressure and LV dP/dT(max) was significantly higher in the treated group than in the control group. The incidence of ventricular fibrillation during reperfusion was 100% and 25% in the control and the OP-2507 groups, respectively. Myocardial ATP content was significantly higher in the treated hearts than that in the control hearts. These results indicate that this stable prostacyclin analogue is beneficial in myocardial ischemia, even without its well known action of preventing platelet aggregation.

Cardiac and hepatic metabolism in spontaneously hypertensive rats following acute blood loss

Seven spontaneously hypertensive rats (SHRs) and eight Wistar-St rats were used to assess the influence of hemorrhage on myocardial and hepatic energy metabolism. They received 2% halothane and pancuronium, 0.3 mg.kg(-1), during preparation. After discontinuation of halothane, blood (2 ml.100 g body weight(-1)) was gradually withdrawn over a 5 min period from a femoral artery. Thirty min after induction of hemorrhage, the heart and liver were removed and myocardial and hepatic metabolites (ATP, lactate, pyruvate and glycogen) were measured by the enzymatic methods. Acidosis and decreased hematocrit were noted in the both groups after hemorrhage. Mean arterial pressure (MAP) in SHR was significantly higher than that in Wistar rat before hemorrhage. However, there were no significant differences in MAP and heart rate between the two groups after hemorrhage. Although there were no significant differences in cardiac metabolites, a significant decrease of hepatic ATP and an increase of hepatic lactate/pyruvate ratio were found in SHR when compared with Wistar rat. These results suggest that human hypertensive disease may run a high risk in connection with acute hemorrhage.

Prostaglandin E1 reduces blood loss during and after resection of lumbar herniated disc

Controlled hypotension was employed during resection of lumbar herniated disc on 10 patients. Prostaglandin E(1) (PG) was used as a hypotensive agent. The systolic blood pressure was lowered less than 100 mmHg in the hypotensive group. The average blood loss during surgery was 95 +/- 41 ml for the hypotensive group compared with 154 +/- 81 ml for the normotensive group ( P < 0.05). The blood loss after surgery was also significantly less in the hypotensive group than in the normotensive group ( P < 0.05). We conclude that PG is an effective hypotensive agent on blood loss during and after surgery.

Functional and metabolic effects of mexiletine in the rat heart-lung preparation

The effects of mexiletine on cardiac function and myocardial metabolism were assessed in the isolated rat heart-lung preparation. Mexiletine 1, 2, 4 or 8 micrograms ml-1 was administered 5 min after the start of perfusion. Heart rate decreased in the 2, 4 and 8 micrograms ml-1 groups significantly following the drug administration. The highest dose of mexiletine reduced cardiac output significantly, and this dose was associated with a higher incidence of dysrhythmias than the other groups. Although there was no significant difference in myocardial glycogen concentration among groups, ATP contents in the 4 micrograms ml-1 and 8 micrograms ml-1 groups were significantly less than in the control group. Lactate contents in the 4 micrograms ml-1 and 8 micrograms ml-1 groups were significantly higher than in the control group. Generally, the therapeutic plasma concentration of mexiletine is 0.5-2.0 micrograms ml-1. These results suggest that mexiletine may have a lesser margin of safety than lignocaine.

[The effect of prostaglandin E1 (PGE1) on body temperature and on postoperative shivering under high dose epidural fentanyl]

Ninety-nine elective abdominal surgeries were performed under high dose epidural fentanyl anesthesia. PGE1 (0.02 microgram.kg-1.min-1 = 0.02 gamma) was administered to 34 patients (0.02 gamma group), and PGE1 (0.05 gamma) was administered to 16 patients (0.05 gamma group). PGE1 was not administered to 49 patients (control group). The effect of PGE1 on body temperature and on postoperative shivering was compared within three groups. In the 0.02 gamma group, the temperature of the fingertip was significantly higher and the rectum-fingertip temperature gradient was significantly lower than in the other groups. The forearm-fingertip temperature gradient was lower in the 0.02 gamma and 0.05 gamma groups than in the control group. The incidence of postanesthetic shivering was significantly lower in the 0.05 gamma group than in the other groups. These results suggest that; 1) PGE1 (0.02 gamma and 0.05 gamma groups) affects the peripheral blood flow and peripheral temperature, and 2) PGE1 (0.05 gamma group) significantly affects the incidence of postanesthetic shivering.

Protective effects of prostaglandin I2 analogues on CPK release in rat’s heart-lung preparation

The effects of prostaglandin I(2) analogues (PGI(2)-a: op-41483 and op-2507) on oxygen toxicity during hyperoxic perfusion were evaluated in an experiment on isolated rat heart lung preparation, with the release of creatine phosphokinase (CPK) in the perfusate blood. There were no significant differences in heart rate and right atrial pressure between PGI(2)-a treated and untreated hearts. The CPK release from the heart with oxygen was significantly higher than that of the air ( P < 0.001). However, the CPK release from the PGI(2)-a treated hearts was significantly less than that from the untreated hearts ( P < 0.05). These results indicate that PGI(2)-a may prevent cell damage which was induced by hyperoxia.

Functional and metabolic effects of propafenone in the rat heart-lung preparation

The effects of propafenone on cardiac function and myocardial metabolism were assessed in the isolated rat heart-lung preparation. Propafenone 0.3, 3 or 30 microg.ml(-1) was administered 5 min after the start of perfusion. Heart rate decreased in the 30 microg.ml(-1) group significantly following the drug administration. The highest dose of propafenone (30 microg.ml(-1)) reduced cardiac output significantly, and this dose was associated with a higher incidence of arrhythmias than the other groups. Although there were no significant differences in myocardial lactate and glycogen concentrations among groups, ATP content in the 30 microg.ml(-1) group was significantly less than that in the control group. As therapeutic plasma concentration of propafenone is about 0.6 (range 0.06 to 1.0) microg.ml(-1), 30 microg.ml(-1) is 50 times greater than its concentration. These results suggest that the negative inotropic and chronotropic effects of propafenone are almost same with those of lidocaine which we have previously reported.

Anaesthetic management of dilated cardiomyopathy with severe ventricular dysrhythmias

A 67-year-old man with dilated cardiomyopathy underwent subtotal gastrectomy. The risks due to anaesthesia and surgery were considered to be very high because of the severe dysrhythmias and renal dysfunction. Anaesthesia was induced with fentanyl and midazolam and maintained with additional fentanyl, midazolam, and 60% nitrous oxide. Dobutamine, dopamine, lignocaine and a temporary pacemaker were used to control cardiovascular responses during surgery. Mild hypotension and tachycardia occurred, but neither circulatory failure nor other major complications were observed during and after the operation.

Combination effect of recombinant human interleukin 1 alpha with antitumor drugs on syngeneic tumors in mice

To investigate the combination effects of recombinant human interleukin 1 alpha (rHu IL-1 alpha) and antitumor drugs, groups of 7 mice bearing syngeneic tumors (Meth A sarcoma in BALB/c mice and colon 26 adenocarcinoma in BALB/c x DBA/2 F1 mice) were treated i.v. with the antitumor drugs according to the early (once daily on days 1, 4, 7, 10, and 13) and/or late (once daily on days 7, 10, 13, 16, and 19) medication schedules in combination with rHu IL-1 alpha administered i.m. at various timings (1 day before, concurrently with, and 1 day after every drug administration). Inhibition rates of the antitumor drugs (mitomycin C, doxorubicin, cisplatin, cyclophosphamide, and 5-fluorouracil) for both the murine tumors were more or less raised by coadministration of rHu IL-1 alpha irrespective of medication schedules and combination timings. After both early and late treatments with the optimal combinations of rHu IL-1 alpha (0.1-3 micrograms/mouse) and cisplatin (2-4 mg/kg) and by the late treatment with the optimal combinations of rHu IL-1 alpha (0.3-3 micrograms/mouse) and carboplatin (32 mg/kg) or thiotepa (4 mg/kg), many mice were completely cured of colon 26 adenocarcinoma and survived for more than 90 days. Combined use of rHu IL-1 alpha and antitumor drugs seems to be beneficial in antitumor chemotherapy.

Functional and metabolic effects of bupivacaine and lignocaine in the rat heart-lung preparation

We have examined the effects of bupivacaine and lignocaine on myocardial metabolism in the rat isolated heart-lung preparation. Bupivacaine 1, 5 or 25 micrograms ml-1 or lignocaine 4, 20 or 100 micrograms ml-1 was administered 5 min after the start of perfusion. Both bupivacaine 25 micrograms ml-1 and lignocaine 100 micrograms ml-1 reduced heart rate significantly. Bupivacaine 25 micrograms ml-1 was associated with a higher incidence of arrhythmias than the other groups. Three hearts in the bupivacaine 25 micrograms ml-1 group (n = 8) and two hearts in the lignocaine 100 micrograms ml-1 group (n = 8) failed (zero cardiac output) at the end of the experiment. Although there were no significant differences in myocardial lactate and glycogen concentrations between groups, ATP content in the bupivacaine 25 micrograms ml-1 and lignocaine 100 micrograms ml-1 groups was significantly less than that in the control group. The results suggest that myocardial depression and subsequent metabolic deterioration occurred with both the high doses of local anaesthetics; these findings do not account for the apparent increased cardiotoxicity of bupivacaine.

Interaction between calcium channel blockers and volatile anaesthetics in the rat heart-lung preparation

We have studied the effects of the calcium channel blockers verapamil, diltiazem and nifedipine and the volatile anaesthetics halothane, enflurane and isoflurane on myocardial metabolism after postischaemic reperfusion in the rat isolated heart-lung preparation. In the presence of the volatile anaesthetics, the preparations were perfused for 10 min, made globally ischaemic for 8 min, and then reperfused for 10 min. Each of the calcium blockers was administered 5 min before ischaemia. Three hearts in the halothane-verapamil group (n = 10) failed to recover from the ischaemia and the recovery time in the same group was significantly longer than in the enflurane-verapamil or isoflurane-verapamil groups. Although there was no significant difference in myocardial lactate concentrations among the groups, ATP and glycogen contents in the halothane-verapamil group were significantly less than those in the other groups. The results suggest that the combination of halothane and verapamil causes significant myocardial depression during recovery from ischaemia and subsequent metabolic deterioration.

Anesthetic influence on myocardial energy metabolism during hemorrhagic shock in rats

Twenty-eight male Wistar rats were used to assess the influence of inhalation anesthetics on myocardial energy metabolism during hemorrhage. They were anesthetized with pentobarbital and divided into four groups: a control group and three others which received 1.2% halothane, 2.2% enflurane or 1.4% isoflurane, respectively. Following a 15-min stabilization period, blood was gradually withdrawn over a 5-min period from a femoral artery. Systolic blood pressure was maintained at 40 mmHg for 30 min. Immediately after hemorrhage, the heart was removed and myocardial metabolites (ATP, ADP, AMP, lactate and glycogen) were measured by the enzymatic methods. Although no significant differences could be detected in ADP, AMP and lactate among the groups, there were significant increases of ATP content in rats receiving halothane and isoflurane when compared with the controls. There were also differences in myocardial glycogen content between the control group and those receiving isoflurane with those receiving halothane or enflurane. These results suggest that halothane or isoflurane may be more desirable than enflurane for maintenance of anesthesia during hypovolemia.

The effects of ulinastatin on cardiac and hepatic energy metabolism in rats subjected to hypovolemic shock

Ulinastatin is a trypsin inhibitor extracted from human urine. In this study the effects of ulinastatin on myocardial and hepatic tissue concentrations of creatine phosphate (CP), ATP, ADP, AMP, lactate, pyruvate, and glycogen have been investigated in rats which were in hemorrhagic shock state. Hypovolemia was induced by bleeding from the femoral artery, and systolic blood pressure was maintained 40 mmHg for 25 min, then ulinastatin 50,000 units.kg(-1) in saline or saline vehicle was intravenously administered. Thereafter the heart and liver were extirpated and frozen quickly with liquid nitrogen. The tissue concentrations of CP, ATP, ADP, AMP, lactate and glycogen were measured enzymatically. Systolic blood pressure elevated significantly after ulinastatin administration. The myocardial tissue CP level was higher in ulinastatin-treated group than that of control group, whereas no significant difference in energy charge between two groups. The hepatic tissue level of AMP, lactate and L/P ratio was lower in ulinastatin-treated group than that of control group, however, no significant difference was found in hepatic tissue level of ATP, ADP and energy charge. From these results it is concluded that ulinastatin can improve the energy metabolism of myocardium to some extent, but not of the liver in rats with hypovolemic shock.

[Effects of inhalation anesthetics on hepatic ATP and L/P ratio in the rat subjected to hemorrhagic shock]

Both anesthetics and hemorrhage may affect the hepatic energy metabolism. The effects of inhalation anesthetics (halothane, enflurane and isoflurane) on hepatic ATP level and L/P ratio were evaluated in rat under hemorrhagic shock. There was no significant difference in the hepatic ATP levels among 4 groups. However the L/P ratio in 3 inhalation anesthetic groups was significantly lower than that in control group. These results suggest that inhalation anesthetics may improve the hepatic energy metabolism during hemorrhagic shock.

In vitro and in vivo antibacterial activities of AT-4140, a new broad-spectrum quinolone

AT-4140, 5-amino-1-cyclopropyl-6,8-difluoro-1,4-dihydro-7-(cis-3,5- dimethyl-1-piperazinyl)-4-oxoquinoline-3-carboxylic acid, showed broad and potent antibacterial activity. Its MICs for 90% of the strains tested were 0.1 to 0.78 micrograms/ml against gram-positive organisms, such as members of the genera Staphylococcus, Streptococcus, and Enterococcus, and 0.0125 to 1.56 micrograms/ml against gram-negative organisms, such as members of the family Enterobacteriaceae and the genera Pseudomonas, Branhamella, Campylobacter, Haemophilus, and Neisseria. Its MICs were 0.025 to 0.78 micrograms/ml against glucose nonfermenters, such as members of the genera Xanthomonas, Acinetobacter, Alcaligenes, Moraxella, Flavobacterium, and Brucella; 0.2 to 0.78 micrograms/ml against anaerobes, such as Clostridium perfringens and Bacteroides fragilis; 0.0125 to 0.05 micrograms/ml against Legionella spp.; 0.0125 to 0.2 micrograms/ml against Mycoplasma spp.; 0.031 to 0.063 micrograms/ml against Chlamydia spp.; and 0.1 to 0.3 micrograms/ml against Mycobacterium spp. The potencies of AT-4140 against gram-negative organisms were comparable to those of ciprofloxacin and higher than those of ofloxacin, enoxacin, and norfloxacin. The potencies of AT-4140 against gram-positive organisms, glucose nonfermenters, anaerobes, Mycoplasma spp., Chlamydia spp., and Mycobacterium spp. were generally higher than those of the quinolones with which AT-4140 was compared. AT-4140 showed good oral efficacy against systemic infections with Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Escherichia coli, and Pseudomonas aeruginosa in mice. Its efficacy was better when a daily dose was given once than when it was given in two doses. Good efficacies of the orally administered drug were also observed in pulmonary, dermal, and urinary tract infection models in mice. The in vivo efficacies of AT-4140 were equal to or better than those of ciprofloxacin, ofloxacin, enoxacin, and norfloxacin.

Effects of sevoflurane on myocardial metabolism during postischemic reperfusion in the rat

In experiments on isolated rat heart lung preparation, the effects of sevoflurane on myocardial metabolism during postischemic reperfusion were evaluated with intramyocardial high energy phosphates, lactate and glycogen. Hearts were perfused for 10 min initially and made globally ischemic for 8 min. Afterwards, they were reperfused for 12 min. Sevoflurane was administered from 5 min after the start of perfusion to the end of reperfusion. There was no significant difference in myocardial lactate levels between the sevoflurane (S) and control groups. However, the myocardial ATP level in Group S was significantly higher than that in control (17.45 +/- 1.51 vs 15.50 +/- 0.87 : P < 0.01). The administration of sevoflurane to the isolated rat heart during pre- and post-ischemia enhanced metabolic recovery in the postischemic state.

Effects of naloxone on cardiac energy metabolism in hypovolemic shock in rats

It has been reported that naloxone may be useful in the treatment of hypovolemic shock. However, the effects of naloxone on cardiac energy metabolism in hemorrhagic shock have not been investigated. The effects of naloxone on myocardial metabolism were evaluated in the rats which were bled to a systolic pressure of 40 mmHg and maintained at that pressure for 30 min. Naloxone (10 mg/kg) was administered intravenously 5 min before the heart was removed. Then the intramyocardial high energy phosphates, pyruvate, lactate, and glycogen were measured. Naloxone increased systolic blood pressure and decreased heart rate significantly. However, there were no significant differences in high energy phosphates, energy charge, pyruvate, lactate and glycogen between the control and naloxone groups. These data suggest that naloxone may have no direct effect on the cardiac energy metabolism in a 30-min hypovolemic shock.