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Biomedical subjects

H Mitsuhata

Publications and source records attributed to H Mitsuhata.

At least 37 records · Page 2Linked to original sources

[The spread of subarachnoid hyperbaric dibucaine in the term parturient].

To study the effect of patient's age, height, body mass index (BMI), site of injection, and volume injected on determining the spread of hyperbaric spinal anesthesia in the term parturient, we performed a retrospective analysis on 86 parturients who had received 0.3% hyperbaric dibucaine for cesarean section. All patients received subarachnoid injection of the drug in the left lateral decubitus position on a horizontal operating table. After the drug was injected, the final cephalad level of analgesia to pinprick was measured. Multiple regression analysis revealed that BMI and volume injected had relatively stronger relation with the spread of sensory analgesia, when compared to the others. However, neither of them was a significant determinant of the level of analgesia. In conclusion, patient's age, height, BMI, site of injection and volume injected were not significant determinants of hyperbaric dibucaine spinal anesthesia in the term parturient.

Anesthesia, Obstetrical↗

[Prostagrandin E1-induced hypotension well maintains cerebral circulation and carbon dioxide reactivity in non-neurosurgical patients under sevoflurane-anesthesia].

To evaluate the effect of prostagrandin E1 (PGE1)-induced hypotension on cerebral blood flow (CBF) and carbon dioxide (CO2) reactivity of CBF, regional cerebral hemoglobin oxygen saturation (rSo2) was measured in non-neurosurgical patients (n = 10) under sevoflurane-anesthesia using near infrared spectroscopy. PGE1 was infused intravenously to maintain arterial pressure at a level of about 75% of the MAP (hypotensive group) under sevoflurane-anesthesia alone (normotensive group). Ventilation was controlled to adjust PaCO2 to hypocapnia (25-30 mmHg), normocapnia (35-40 mmHg) and hypercapnia (45-50 mmHg) in both normotensive and hypotensive groups. rSo2 during hypotension did not change by hypocapnia and normocapnia, but significantly increased by hypercapnia, compared with rSo2 during normotension. Significant correlations between rSo2 and PaCO2 during both normotensive and hypotensive groups were observed. Slope of the regression line of rSo2 and PaCO2 did not differ between the normotensive and hypotensive groups. When arterial oxygen content and cerebral metabolic rate of oxygen are constant, changes in rSo2 correlate with those of CBF. Therefore, CBF and CO2 reactivity of CBF that indicates autoregulation in response to changes in CO2 during hypotension were maintained as those during normotension. The results show that PGE2-induced hypotension maintains CBF and CO2 reactivity well in non-neurosurgical patients under sevoflurane anesthesia.

Adolescent↗

[Premixing lidocaine reduces the incidence and severity of pain on injection of propofol].

The purpose of this study was to confirm the effect of premixed lidocaine for the reduction of pain during injection of propofol in adult patients. We conducted a prospective, randomized, double-blind trial on 106 patients. In the study group (n = 54), lidocaine 40 mg (2 ml of lidocaine 2%) was added to 180 mg of propofol (18 ml). In the control group (n = 52), 2 ml of normal saline was added to 180 mg of propofol. The pain on injection was rated as none, mild, moderate, or severe. Eleven patients (20.4%) in the study group experienced pain compared with 25 (48.1%) in the control group. Thirteen in the control group complained moderate or severe pain compared with only one in the study group. In conclusion, lidocaine 40 mg premixed with 180 mg propofol significantly reduces the incidence and severity of pain associated with propofol injection.

Adult↗

[Massive bleeding from the ruptured liver and the inferior vena cava controlled with autotransfusion and cerebral ischemia treated with mild hypothermia].

A patient suffered massive bleeding from the ruptured liver and laceration of the inferior vena cava due to traffic accident, and developed hypotension and decreased level of consciousness. The patient was transferred to our hospital for an emergency operation against intra-abdominal massive bleeding. This massive bleeding was controlled with autotransfusion using washing salvaging autotransfusion device (Cell Savor). Suspected brain ischemia was treated with intended mild hypothermia. When blood pressure decreased to 30 mmHg of systolic pressure over 7 minutes during the operation, suggesting the possible brain ischemia, mild hypothermia was maintained at 33.8 degrees C. Total bleeding volume was 16,700 ml, and total transfused volume was 10,700 ml. Of total transfused volume, 4,500 ml was washed salvaged blood using the intraoperative autotransfusion device. No neurological deficit was found during the postoperative course. The patient was discharged uneventfully on the 20th postoperative day. In conclusion, intraoperative autotransfusion with washed salvaged blood is a useful method for treatment of massive bleeding, and mild hypothermia is efficacious for protecting the brain from ischemia resulting from accidental hypotension.

Accidents, Traffic↗

[Intraoperative re-rupture of gastric varix immediately after the start of an operation in a patient with liver cirrhosis].

Gastroesophageal variceal hemorrhage is a rare complication during an operation. We present a case of gastric variceal re-rupture during an emergent operation for devascularization of the gastric veins. The patient was a 72-year old man with liver cirrhosis, who developed gastric variceal hemorrhage on the day of surgery. Sclerotherapy with an endoscope was performed, and the hemorrhage was controlled four hours before entering the operating theater. The induction of anesthesia and tracheal intubation were done with rapid sequence because the patient was regarded as full stomach. Induction was completed successfully. However, gastric varix ruptured immediately after the beginning of the surgery. The hemorrhage into the stomach amounted to 2,165 ml. The patient developed hypotension of 40 mmHg of systolic pressure for 15 minutes. With fluid resuscitation, continuous infusion of dopamine and ligation of varix, the patient recovered from this hypotensive event. No neurological deficit developed postoperatively. Portal hypertension results from increased resistance to portal venous blood flow or increased portal venous blood flow. Therefore, increased intravascular volume may play a significant role in precipitating variceal hemorrhage. In this case, abrupt circulatory change due to inadequate depth of anesthesia may partly cause massive hemorrhage. In conclusion, since potential adverse effects of increased blood volume and hepatic resistance on variceal hemorrhage must be considered during anesthesia, patients with episode of variceal hemorrhage should be treated as full stomach although endoscopic findings before the surgery indicate controlled hemorrhage from varix.

Aged↗

Failed spinal anaesthesia: cause identified by MRI.

PURPOSE: To determine the cause of failed spinal anaesthesia, magnetic resonance images of the lumbar spine were examined. CLINICAL FUTURES: A 28-yr-old woman, scheduled for closure of a rectal fistula under spinal anaesthesia, hyperbaric tetracaine 12.5 mg injected into the subarachnoid space at L3-4 repeatedly resulted in restricted sacral spread. Magnetic resonance imaging showed that the cylindrical dimension of the lumbar spinal canal was wider than in normal subjects, suggesting a larger volume of CSF within the dural sac below the termination of the cord. The summit of the lumbar convexity was located at L3, which was more cephalad than the L3-4 puncture site. CONCLUSION: The uncommon anatomical characteristics of the lumbar spinal canal identified by magnetic resonance imaging were considered to be the reason for the restricted sacral spread observed repeatedly in this patient.

Adult↗

Convulsions associated with epidural analgesia during sevoflurane anaesthesia.

A three-year-old girl who underwent an operation for adrenal neuroblastoma was anaesthetized with sevoflurane and epidural analgesia. In the immediate recovery period she had convulsions. The convulsions were successfully treated with thiopentone and sevoflurane, there were no neurological sequelae. The convulsions were considered to be a manifestation of mepivacaine toxicity because of a high plasma mepivacaine concentration. Complications of paediatric regional analgesia and manifestations of mepivacaine toxicity under sevoflurane anaesthesia are discussed.

Analgesia, Epidural↗

Airway management for patients with a tracheal bronchus.

A tracheal bronchus is an aberrant, accessory or ectopic bronchus arising almost invariably from the right lateral wall of the trachea, causing hypoxaemia, atelectasis, or both, during anaesthesia. We describe two patients with a tracheal bronchus found before anaesthesia. One tracheal bronchus was found by tracheobronchoscopy and the other by chest x-ray. Because of recognition of the anomaly before operation, anaesthesia was uneventful in each patient.

Anesthesia, General↗

Inflammatory changes after extradural anaesthesia may affect the spread of local anaesthetic within the extradural space.

We have assessed cephalad spread of analgesia in 491 patients undergoing extradural anaesthesia at the L2-3 or L3-4 interspace. Patients were classified into one of three groups based on the number of previous lumbar extradural anaesthesia procedures: none (group I, n = 339), one (group II, n = 82), and two or more (group III, n = 70). Cephalad spread of analgesia was greater in group I than in groups II and III, regardless of the puncture site. In addition, we examined the extradural space using a flexible extraduroscope in 32 patients who were excluded from the analysis of spread. Extraduroscopy showed the extradural space to be patent in patients with no history of prior lumbar extradural anesthesia, but it was not clearly identified in patients who had received extradural anaesthesia one or more times because of aseptic inflammatory changes, including proliferation of connective tissue, adhesions between the dura mater and the ligamentum flavum, granulation and changes in the ligamentum flavum. Extradural anaesthesia may cause aseptic inflammatory changes in the extradural space which may reduce the spread of analgesia.

Adult↗

The effects of sevoflurane and isoflurane anesthesia on renal tubular function in patients with moderately impaired renal function.

Increasing evidence indicates that sevoflurane anesthesia does not impair renal function in healthy patients despite higher concentrations of plasma inorganic fluoride. However, whether sevoflurane further affects renal tubular function in patients with impaired renal function is not known. We compared the effect of sevoflurane anesthesia with that of isoflurane anesthesia on renal tubular function in patients with moderately impaired renal function. Fourteen patients with creatinine clearance between 10 and 55 mL/min were anesthetized with either sevoflurane or isoflurane using a semiclosed circuit system. Plasma inorganic fluoride concentrations and urine N-acetyl-beta-D-glucosaminidase (NAG), gamma-glutamyltranspeptidase (gamma-GTP), and beta 2-microglobulin (beta 2MG) excretions were measured up to post-anesthetic day 14. Although both the peak plasma inorganic fluoride concentrations and the areas under the curve of plasma inorganic fluoride concentration versus time were significantly greater in the sevoflurane group than in the isoflurane group, urine NAG, gamma-GTP, and beta 2MG excretions per day did not differ between the two groups. These results indicate that sevoflurane and isoflurane may have similar effects on the renal tubules in patients with moderately impaired renal function.

Acetylglucosaminidase↗

Sevoflurane is equivalent to isoflurane for attenuating bupivacaine-induced arrhythmias and seizures in rats.

The effects of sevoflurane on bupivacaine toxicity have not been defined. The purpose of this study was to investigate the effects of sevoflurane and isoflurane on bupivacaine-induced arrhythmias and seizures in rats. Thirty-seven Sprague-Dawley rats received bupivacaine intravenously at a constant rate of 2 mg.kg-1.min-1 until both arrhythmias and seizures occurred while electrocardiogram (ECG) and electroencephalogram (EEG) recordings were made. The cumulative doses of bupivacaine inducing arrhythmias and seizures were determined in the presence of 1 minimum alveolar anesthetic concentration (MAC) of sevoflurane (sevoflurane group, n = 14) or isoflurane (isoflurane group, n = 10) and in the absence of anesthetic (control group, n = 13). The cumulative doses of bupivacaine inducing arrhythmias and seizures were larger in the sevoflurane and isoflurane groups than in the control group and were similar in the sevoflurane and isoflurane groups. These results indicate that sevoflurane and isoflurane attenuate bupivacaine-induced arrhythmias and seizures in rats.

Anesthetics, Inhalation↗

Dibutyryl cAMP improves systemic vasoconstriction caused by endotoxin in dogs.

We studied whether dibutyryl cyclic adenosine monophosphate (DbcAMP), which freely penetrates into the cells, improves systemic vasoconstriction caused by endotoxin in dogs. Thirteen anesthetized dogs were randomized into three groups. The endotoxin (ETX) group (n = 5) received only Escherichia coli endotoxin (3 mg.kg-1, intravenously). The ETX + DbcAMP group (n =5) received DbcAMP (6 mg.kg-1, intravenously) 30 min before the administration of endotoxin. The DbcAMP group received the same dose of DbcAMP 30 min after administration of saline. In the ETX group, systemic blood pressure and cardiac index significantly decreased, and systemic vascular resistance significantly increased, while in the ETX + DbcAMP group, increases in systemic and pulmonary vascular resistances after the administration of endotoxin were attenuated. DbcAMP did not cause hemodynamic changes in normal dogs. Plasma concentrations in thromboxane B2 in the ETX group were higher than in the ETX + DbcAMP group. Also, the change in plasma cyclic AMP concentrations showed a good logarithmic correlation with the change in plasma thromboxane B2 concentrations after the administration of endotoxin (r = .908, log (delta T x B2) = -.002* (delta cAMP) + 3.786). We conclude that DbcAMP improves systemic vasoconstriction caused by endotoxin in dogs. The beneficial mechanism of DbcAMP on systemic vasoconstriction after the administration of endotoxin may be partially due to inhibition of thromboxane B2.

Animals↗

In vivo production of nitric oxide in the canine heart in IgE-mediated anaphylaxis.

We investigated the production of nitric oxide (NO) in the canine anaphylactic heart in vivo using an NO-selective electrode. Seven dogs with positive sensitivity to Ascaris Suum were studied. Ascaris Suum was administered into the systemic circulation to induce anaphylaxis, and NO, blood pressure, heart rate, end-diastolic left ventricular pressure, cardiac output, and the maximum rate of rise of left ventricular pressure were monitored for 60 min. The electrode was placed on the surface of the left ventricle adjacent to the interventricular branches of the left coronary artery. NO concentration increased significantly during the period from 2 to 3 min, and tended to increase during the period from 4 to 15 min after antigen challenge, and almost returned to baseline after 20 min. In conclusion, increases in NO in the heart are only observed during the early phase of anaphylaxis.

Anaphylaxis↗

[Effect of sevoflurane on release of TNF-alpha and IL-1 beta from human monocytes].

Although isoflurane inhibits TNF-alpha and IL-1 beta release from human monocytes stimulated by LPS in dose dependent fashion, it is unclear whether sevoflurane has the same effects. Therefore, we investigated whether sevoflurane could inhibit TNF-alpha and IL-1 beta secretions from human monocytes stimulated by LPS in dose dependent fashion in vitro. Human monocytes stimulated by LPS were cultured for 3 h in the presence of sevoflurane 1% or 5%. Another group of human monocytes were cultured in the absence of sevoflurane. TNF-alpha and IL-1 beta increased after stimulation of LPS and these increases were not inhibited by sevoflurane in a dose dependent fashion. We conclude that sevoflurane does not inhibit TNF-alpha and IL-1 beta release from monocytes stimulated by LPS.

Anesthetics, Inhalation↗

[Emergency internal carotid artery ligation using near infrared spectroscopy].

We anesthetized a patient who received an emergency internal carotid artery ligation. Regional cerebral oxygen saturation (rSO2) was measured with near infrared spectroscopy (NIRS) during the whole anesthetic course. The sensor was placed on the left forehead of the patient. Decrease in blood pressure was reflected in the decrease in rSO2. The rSO2 was not altered by internal carotid ligation. However, cerebral infarction in the middle cerebral artery region, the onset of which remained unclear, was revealed postoperatively, regardless of a stable rSO2 during the operation. This monitor may provide useful information regarding the cerebral circulation during the operation in such a case as the present one, but this monitor reflects only the oxygenation of the region on which the sensor was placed. Thus, we should keep in mind the limitation in detecting cerebral dysfunction using NIRS.

Anesthesia, General↗

[Clinical evaluation of a new programmable syringe infusion pump].

A new programmable syringe infusion pump, Auto Syringe Model AS 40 A, was evaluated for infusion of muscle relaxants, vasodilators and opioids in 4 surgical patients. Every drug mentioned above was easily adjusted according to surgical requirement in these patients. Auto Syringe Model AS40A is light and compact. Its major advantages lie in the mechanisms for delivery of a bolus dose and automated delivery of intermittent doses, automatic rate calculation, and the applicability to various sizes of syringes. Auto Syringe Model AS40A was found to be very useful for intravenous infusion of drugs.

Adult↗

[Cesarean section in a morbidly obese parturient under epidural anesthesia].

A 26-yr-old morbidly obese parturient with a body mass index of 62 kg.m-2 underwent elective cesarean section for preeclampsia under epidural anesthesia. The distance between the skin and the epidural space was about 9 cm at the L3-4 interspace via mid approach. Epidural catheter was inserted 5 cm cephalad in the sitting position and a bolus of 17 ml of mepivacaine 1.5% was given in the supine position. The T5 level of analgesia was obtained 10 min later. Forty minutes after the start of the surgery, a female newborn weighing 3,206 g was delivered with an Apgar score 8 at 1 min and 9 at 5 min. Throughout the surgery, sufficient analgesia was obtained and any complications such as severe hypotension and respiratory depression did not develop. Postoperative pain was relieved sufficiently with a continuous epidural infusion of 0.25% bupivacaine at a rate of 0.5 ml.h-1 for two days. Both maternal and neonatal postpartum courses were uneventful. In conclusion, elective cesarean section in a morbidly obese parturient was successfully managed with epidural anesthesia. This indicates that an elective cesarean section under epidural anesthesia reduce the risk of perioperative complications in a morbidly obese parturient.

Adult↗