Is protease inhibitor a choice for the treatment of pre- or mild disseminated intravascular coagulation?

OBJECTIVE

To investigate the effect of a protease inhibitor, gabexate mesylate, on patients with pre- or mild disseminated intravascular coagulation (DIC) in comparison with a control group receiving no anticoagulation therapy.

DESIGN

Prospective, randomized, controlled study.

SETTING

General intensive care unit at a general hospital.

PATIENTS

Adult patients (40) with a DIC score between 6 and 8 (pre- or mild DIC).

INTERVENTIONS

In 20 patients, gabexate mesylate (2 mg/kg/hr) was administered as 2 mL/hr in saline (treated group) and in another 20 patients, saline (2 mL/hr; control group) was administered during the study (7 days).

MEASUREMENTS AND MAIN RESULTS

The following variables were determined at the time of admission to the intensive care unit before treatment and 1, 3, 5, and 7 days thereafter: platelet count, antithrombin III activity, serum or plasma concentrations of fibrinogen, fibrin degradation product, D-dimer, fibrin monomer, thrombin-antithrombin III complex, and plasmin-plasmin inhibitor complex, prothrombin time ratio, and DIC score. Two patients in the treated group and four in the control group were excluded from the study because they died during the study; therefore, 34 patients were analyzed. The measured variables of coagulation and fibrinolysis were not significantly different between the two groups, except for the D-dimer on day 3 (the treated group showed a higher concentration). D-dimer concentration and DIC score went down more quickly in the control group than the treated group, but not significantly. The mortality rate at 1 month was 40% (8 of 20) in the treated group and 35% (7 of 20) in the control group, without any differences between the two groups.

CONCLUSIONS

In a limited number of patients (n = 34), gabexate mesylate (2 mg/kg/hr) could not inhibit coagulation or fibrinolysis and gabexate mesylate could not improve the DIC score or mortality rate in pre- or mild DIC.

[Coronary artery spasm during vascular surgery]

A 56-year-old male with arteriosclerosis obliterans was scheduled for aorto-biiliac artery bypass graft surgery. He had episodes of chest pain lasting for several minutes. Preoperative electrocardiogram (ECG) and myocardiac scintigram showed no abnormal findings. Anesthesia was induced with thiopental 225 mg, fentanyl 100 micrograms and tracheal intubation was facilitated with vecuronium 10 mg. Anesthesia was maintained with O2 2 l.min-1, N2O 4 l.min-1, sevoflurane 0.5-1% and epidural injection of 1% mepivacaine 6-10 ml.hr-1. Nitroglycerin was infused at a rate of 0.125 microgram.kg-1.min-1. During surgery, a transient elevation of the ST segment occurred three times in lead II of the ECG. For the first episode with decrease in blood pressure at declamping the external iliac artery, administration of phenyrephrine 100 micrograms improved ST segment elevation in ECG. For the second event with a slight decrease in blood pressure, an increased dose of nitroglycerin decreased ST segment elevation. The third incident with increased blood pressure and heart rate was alleviated by decreasing the dose of dopamine. Postoperative ECG and serum creatine kinase level were within normal limits. These three episodes of ST segment elevation might be due to coronary spasms induced by decreased blood pressure or increased blood pressure and heart rate.

[The necessity and the efficacy of the second administration of midazolam for sedation during spinal anesthesia]

We investigated the necessity of the second additional administration of intravenous midazolam for sedation during spinal anesthesia and the adequate dose if necessary. Fifty patients with ages between 35 to 70 years for spinal anesthesia were administered midazolam 0.05 mg.kg-1 intravenously during surgery. Thirty-four patients opened their eyes spontaneously and to these patients midazolam 1 mg was administered every three minutes until patients closed their eyes. All 34 patients closed their eyes with 1 mg of midazolam. Patients opened their eyes again at 47 +/- 16 minutes (mean +/- SD) after the first dose (0.05 mg.kg-1) and at 24 +/- 14 minutes after the second dose (1 mg). The decreases in blood pressure, heart rate and percutaneous arterial oxygen saturation after the administration of midazolam were less after the second administration than those after the first one. The percent of patients with amnesia was larger in the patients with only first administration than those with the second dose. These results suggest that the additional dose of midazolam is not necessary after intravenous midazolam 0.05 mg.kg-1 until patients open their eyes and the additional 1 mg is useful even after patients have opened their eyes.

Molecular identification and pharmacological characterization of adenosine receptors in the guinea-pig colon

The aim of this study is to elucidate the role of adenosine in the motor function of the guinea-pig distal colon.2 To determine whether adenosine A(1) receptors and A(2B) receptors are expressed in the guinea-pig colon, we employed the reverse transcription-polymerase chain reaction (RT - PCR). The gene expression of A(1) receptor and A(2B) receptor was found for the first time in the guinea-pig proximal and distal colon.3 Adenosine A(1) agonist N(6)-cyclopentyladenosine (CPA), and A(1)/A(2) agonist 5'-N-ethylcarboxamidoadenosine (NECA) concentration-dependently inhibited neurogenic responses to electrical field stimulation (EC(50)=1.07x10(-8) and 2.12x10(-8) M) in the longitudinal muscle, but A(2A) agonist 2-p-(2-carboxyethyl)phenylethylamino-5'-N-ethycarboxamido-ad enosine (CGS21680) had only a slight inhibitory effect (25.9%, 1 microM). A(1) antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 10 nM: A(1) selective concentration) antagonized responses to CPA and NECA. Furthermore, the affinity order of antagonists at inhibiting the effect NECA was: DPCPX>8-phenyltheophylline (8-PT: A(1)/A(2) antagonist).3 In the presence of tetrodotoxin (TTX, 0.3 microM), CPA and NECA relaxed myogenic precontraction induced by KCl (50 mM) (EC(50)=1.26x10(-5) and 1.04x10(-5) M, respectively), but CGS21680 (1 microM) did not cause any relaxation. DPCPX did not affect responses to CPA and NECA at a concentration of 10 nM, but a higher concentration (1 microM) of DPCPX and 10 microM of 8-PT antagonized those responses.5 These data lead us to the hypothesis that adenosine may mediate relaxation through two different inhibitory receptor subtypes; A(1) receptors on the enteric neuron and A(2B) receptor on the smooth muscle in the guinea-pig distal colon.

Expression of lbx1 involved in the hypaxial musculature formation of the mouse embryo

Somites are the source of hypaxial musculature including skeletal muscles of the limb, tongue, and trunk. To get insight into the function of mouse Lbx1 homeobox gene in early somitic mesoderm differentiation, in situ hybridization analyses were performed. At the 4-6 somite stage (8 dpc), Lbx1 was first expressed in the lateral portion of the epithelial somite and dermomyotomal epithelium. This was in contrast to the expression of myf-5 in the medial region of the somite. The lateral expression of Lbx1 in somitic mesoderm then occurred regionally along the anterior-posterior body axis. Later, at 10 dpc (stage 1 of limb bud development), Lbx1-positive migrating cells originated in the lateral dermomyotomal lips at occipital, forelimb, and hindlimb levels. They also expressed Pax-3 and c-met, known as markers of the migrating limb muscle precursor cells. In stage 4 hindlimb bud (11.5 dpc), the dorsal and ventral muscle precursor populations expressed Lbx1. In stage 8 forelimb buds (12.5 dpc), Lbx1 expression was reduced in the proximal muscle masses, where the high expression of myogenin accompanying muscle differentiation was detected. These results suggest that mouse Lbx1 might be involved in the commitment or determination of a muscle cell subpopulation during hypaxial musculature development. J. Exp. Zool. 286:270-279, 2000.

Expression of cofilin isoforms during development of mouse striated muscles

Cofilin (CF) is an actin regulatory protein that plays a critical role in actin filament dynamics in a variety of cells. Two cofilin isoforms. muscle-type (M-CF) and nonmuscle-type (NM-CF) encoded by different genes, exist in mammals; in the adult, the former is predominantly expressed in muscle tissues, while the latter is distributed in various non-muscle tissues (Ono et al., 1994). In this study, we examined cofilin isoform expression during skeletal and cardiac muscle development in mice using cDNA probes and antibodies which distinguish the isoforms. We found that the expression of M-CF was initiated in terminally differentiated myogenic cells in both the myotome and limb buds. In myogenic cell cultures, its expression occurred coupled with myotube formation. NM-CF was expressed in developing skeletal and cardiac muscles but disappeared from skeletal muscle during postnatal development, while its expression persisted in the heart, even in adult mice. A similar situation was observed in the heart of other mammals. Thus, it is likely that the both cofilin isoforms are involved in the regulation of actin assembly during myofibrillogenesis. Only M-CF could be involved in actin dynamics in mature skeletal muscle, while both isoforms could be in the mature heart.

Reproducibility of the drug effects over time on chronic lumbar epidural catheterization in rats

Chronically implanted epidural catheters lead to a reaction that impedes drug action. The purpose of this study in a rat model with chronically implanted epidural catheters was to investigate the change in opiate activity and histology over time with this model. A skin incision of 1-2 cm was made at the T 13 level on the back of male Sprague-Dawley rats under halothane anesthesia. Muscles were dissected bluntly from the vertebrae, and the intervertebral ligament was cut to insert an epidural catheter (polyethylene tube, outer diameter of 0.14 mm) 2-cm caudally. The longer portion of the catheter was passed through a trocar subcutaneously to exit the dorsal neck area. One, two, and six days after catheterization, the effects of morphine on thermal stimulation using the hot-box test and histology were investigated. Analgesic effects of morphine 6 days after catheterization were significantly less than those on the first and second days. Histologically, evidence of inflammation around the catheter was noted as early as 4 h after catheterization. Pericatheter fibrosis was severe after 2 days. We conclude that this model of chronic epidural catheterization in the rat evoked a histologically defined, pharmacodynamically significant, local reaction 2 to 6 days after catheter implantation.

IMPLICATIONS

A rat model with chronically implanted epidural catheters should be used for testing the analgesic effects of drugs within two days after catheterization.

Cerebrovascular carbon dioxide reactivity during general anesthesia: a comparison between sevoflurane and isoflurane

We compared cerebrovascular carbon dioxide reactivity during the administration of sevoflurane and isoflurane anesthesia by measuring cerebral blood flow velocity (CBFV) as an indirect measurement of cerebral blood flow. Thirty patients, 20-70 yr old, undergoing lower abdominal surgery and without known cerebral or cardiovascular system disease, were randomly assigned to either sevoflurane or isoflurane treatment groups. Anesthesia was induced with thiopental 5 mg/kg IV and maintained with either sevoflurane or isoflurane in 67% nitrous oxide and oxygen. The CBFV and pulsatility index (PI) of the left middle cerebral artery were monitored with transcranial Doppler. The P(ETCO)2 was increased stepwise from 20 to 50 mm Hg by changing the respiratory rate with a constant tidal volume. At every 5-mm Hg stepwise change in P(ETCO)2, CBFV and PI were recorded. CBFV increased with increasing P(ETCO)2. CBFV was significantly smaller in the isoflurane group at P(ETCO)2 = 20-40 mm Hg than in the sevoflurane group. The rate of change of CBFV with changes in CO2 was larger in the isoflurane group than in the sevoflurane group. PI was constant over time and was not different between groups. In conclusion, hypocapnia-induced reduction of intracranial pressure might be more effective during the administration of isoflurane than sevoflurane.

IMPLICATIONS

Changes in cerebral blood flow caused by the changes of carbon dioxide tension are greater during the administration of isoflurane anesthesia compared with sevoflurane anesthesia. Attempts to decrease intracranial pressure by decreasing carbon dioxide tension may be more successful during isoflurane than sevoflurane anesthesia administration.

A 59 amino acid insertion increases Ca(2+) sensitivity of rbslo1, a Ca2+ -activated K(+) channel in renal epithelia

We previously cloned a MaxiK channel alpha-subunit isoform, rbslo1, from rabbit kidney with an amino acid sequence highly homologous to mslo but with a 59 amino acid insertion between S8 and S9 (Morita et al., 1997. Am. J. Physiol. 273:F615-F624). rbslo1 activation properties differed substantially from mslo with much greater Ca2+ sensitivity, half-activation potential of -49 mV in 1 micron m Ca2+. We now report single-channel analysis of rbslo1 and delA, a construct produced by removal of the 59 amino acid insertion at site A. delA is identical to mslo from upstream of S1 to downstream of S10 with the exception of 8 amino acids. Slope of the steady-state Boltzmann voltage activation curve was 8.1 mV per e-fold change in probability of opening for both rbslo1 and delA. The apparent [Ca2+](i) properties in delA were more like mslo but the voltage-activation properties remained distinctly rbslo1. Ca2+ affinity decreased and transmembrane voltage effects on apparent Ca2+ affinity increased in delA. The differences between rbslo1 and other cloned channels appear to be localized at insertion site A with both the insertion sequence and amino acid substitutions near site A being important. The steeper activation slope makes the channel more responsive to small changes in transmembrane voltage while the insertion sequence makes the channel functional at physiological low levels of [Ca2+](i).

Efficiency of a new fiberoptic stylet scope in tracheal intubation

BACKGROUND

Failed or difficult tracheal intubation is an important cause of morbidity and mortality during anesthesia. Although a number of fiberoptic devices are available to circumvent this problem, many do not allow manual control of the flexion of the tip and necessitate time-consuming preparation, special training, or the use of an external light source. To improve these limitations, the authors designed a new fiberoptic stylet scope (FSS) that has a simple form of a standard stylet with the fiberoptic view and maneuverability of its tip. This study was undertaken to prospectively evaluate the effectiveness of the FSS in tracheal intubation.

METHODS

Thirty-two patients undergoing general surgery participated in this study. The authors used a standard laryngoscope only to elevate the tongue, then tracheal intubation was attempted with the glottic opening being viewed only through the FSS. The success rate, time necessary for intubation, hemodynamics, and adverse effects were recorded.

RESULTS

The success rate of tracheal intubation on the first attempt using the FSS was 94% (30 of 32 patients), and the remaining two patients were intubated successfully on the second attempt. The mean time necessary for the intubation procedure was 29+/-14 s in all patients (mean +/- SD). Changes in hemodynamics during intubation were well within acceptable ranges. There were no major adverse effects, but minor sore throat (28%) and minor hoarseness (25%) on the first postoperative day.

CONCLUSIONS

Tracheal intubation using the FSS proved to be a simple and effective technique for airway management.

[Perioperative management of vagotomy for treatment of frequent syncope]

A 66-year-old man was admitted to our hospital because of frequent chest pain and loss of consciousness. He had a 6-year history of angina and has taken nitroglycerin. He had received total laryngo-pharyngoectomy with the graft by jejunum for pharyngeal cancer seven months ago. The tumor, however, recurred at the neck lymphnodes. Against the increased episodes of severe bradycardia and loss of consciousness, he was scheduled to undergo subemergent vagotomy at proximal and distal side of the cancer since the cancer surrounded the nutrition vessels of the graft. Atropine 0.25 mg i.m. and 0.25 mg i.v. were administered to treat bradycardia and hypotension in the morning of operation. As a premedication atropine 0.5 mg p.o. was given. Anesthesia was induced with midazolam 3 mg, sevoflurane 5%, nitrous oxide 8 l.min-1 in oxygen 4 l.min-1. Intubation through tracheostomy was facilitated with fentanyl 100 micrograms. When the operator touched the neck, heart rate and blood pressure decreased suddenly to 35 beats.min-1 and 62 mmHg/20 mmHg, respectively. Atropine 1 mg i.v. and ephedrine 8 mg i.v. were effective. This was the only episode during surgery. After surgery all bradycardiac episodes have gone away without atropine or any other treatment. His frequent attack of bradycardia and hypotension with syncope was due to vagal reflex by the recurrent tumor.

CHox11L2, a Hox11 related gene, is expressed in the peripheral nervous system and subpopulation of the spinal cord during chick development

cHox11L2, the chick counterpart of mouse Hox11L2, was isolated. cHox11L2 was expressed in the developing chick peripheral nervous system, i.e. sensory cranial nerves of placodal ectoderm origin, sympathetic ganglia, dorsal root ganglia and enteric ganglia as well as a limited regions of the spinal cord. In neuronal derivatives of the neural crest, cHox11L2 was expressed in the postmigratory cells and not in the migrating neural crest cells. Furthermore, intense signals of cHox11L2 mRNA were detected also in the spinal cord and the dorsal roots of 10-day embryos. No transcripts were detected in the spinal cord of the postnatal day-2 animals. These results suggest that cHox11L2 might play a role in neuronal differentiation during chick nervous system development.

Acute phase histopathological study of spinally administered midazolam in cats

Midazolam may be a useful analgesic when administered intrathecally. However, neurotoxicity must be excluded. The purpose of this study was to investigate whether spinally administered midazolam induces acute-phase histopathological or inflammatory reactions of the spinal cord. A lumbar laminectomy was performed on 40 cats, and their spinal cords were exposed. Midazolam 10 mg (2 mL, n = 20 cats) or saline 2 mL (20 cats) was administered directly to the spinal cord. At 1, 2, 4, or 6 h after the administration, cats were killed, and the lumbar spinal cord was removed and fixed in 10% formalin. Histology was examined using light microscopy with hematoxylin and eosin staining. Both groups showed slight to moderate changes in the spinal cord, but no severe damage was observed. Inflammatory reactions were seen in only one cat in the saline group with slight neutrophil infiltration. These changes were not different between the midazolam group and the saline group. In conclusion, up to 6 h after direct exposure to midazolam, no acute histological damage or inflammatory reaction of the spinal cord was seen in cats.

IMPLICATIONS

Spinally administered midazolam, even in large doses, does not cause acute neurotoxicity or inflammation of the spinal cord.

Anaesthetic management of two paediatric patients with Hecht-Beals syndrome

We undertook the anaesthetic management of two children with Hecht-Beals syndrome for orthopaedic surgery under general anaesthesia. Both patients had arachnodactyly, kyphoscoliosis, and multiple congenital joint contractures, but limited mandible excursion was not obvious preoperatively in either, although mental retardation made it difficult for them to cooperate with mouth examination. They had no apparent difficulties with their mouths in daily activities. The anaesthesia records of one patient showed that intubation had been difficult in an earlier procedure. The other patient also had a history of difficult intubation, with slight tearing of the corners of her mouth during an intubation procedure. During slow induction of general anaesthesia with sevoflurane, face mask ventilation was easily performed. We attempted to visualize the larynx under anaesthesia with muscle relaxation, but we were unsuccessful because of the limited mouth opening. After several trials, blind oral intubations were fortunately successful in both patients. There were no postoperative problems with the airway.

Antitumor activity and novel DNA-self-strand-breaking mechanism of CNDAC (1-(2-C-cyano-2-deoxy-beta-D-arabino-pentofuranosyl) cytosine) and its N4-palmitoyl derivative (CS-682)

We have studied the antitumor activity and the novel DNA-self-strand-breaking mechanism of CNDAC (1-(2-Ccyano-2-deoxy-beta-D-arabino-pentofuranosyl)cytosine) and its N4-palmitoyl derivative (CS-682). In vitro, CS-682 showed strong cytotoxicity against human tumor cells comparable with that of CNDAC; both compounds displayed a similar broad spectrum. In vivo, however, orally administered CS-682 showed a more potent activity against human tumor xenografts than CNDAC, 5'-deoxy-5-fluorouridine, 5-fluorouracil and 2',2'-difluorodeoxycytidine. Moreover, CS-682 was effective against various human organ tumor xenografts at a wide dose range and with low toxicity, and was effective against P388 leukemic cells resistant to mitomycin-C, vincristine, 5-fluorouracil or cisplatin in syngeneic mice. CNDAC, an active metabolite of CS-682, had a prolonged plasma half-life after repeated oral administrations of CS-682 but not after oral administrations of CNDAC itself. This difference may partially explain the higher antitumor activity of CS-682 relative to CNDAC. In both CNDAC- and CS-682-treated carcinoma cells, CNDAC 5'-triphosphate (CNDACTP) was generated and incorporated into a DNA strand. High performance liquid chromatography (HPLC) and mass spectrometric analysis of the nucleosides prepared by digestion of the DNA from the CNDAC-treated cells detected ddCNC (2'-Ccyano-2',3 '-didehydro-2',3 '-dideoxycytidine), which was shown to be generated only when the self-strand-breakage of CNDACTP-incorporated DNA occurred. The cytotoxicity of CNDAC was completely abrogated by the addition of 2'-deoxycytidine and was low against cells with decreased deoxycytidine kinase. Our results suggest that CNDAC is converted to CNDACMP by deoxycytidine kinase and that the resulting CNDACTP incorporated into a DNA strand as CNDACMP may induce DNA-self-strand-breakage. This novel DNA-self-strand-breaking mechanism may contribute to the potent antitumor activity of CS-682.

Optimal length and angle of a new lightwand device (Trachlight)

STUDY OBJECTIVE

To investigate the effects of angle and length of the Trachlight lightwand and the effect of obesity on transillumination of the neck and difficulty of intubation.

DESIGN

Prospective, randomized study.

SETTING

Operating room of a university hospital.

PATIENTS

270 patients, aged 30 to 70 years, requiring anesthesia.

INTERVENTION

Three different studies were performed. 1) One hundred twenty adults for general anesthesia to test the effect of the angle, 2) 120 patients for the length of the extrusion, and 3) 30 patients with body weight > or = 120% of the standard (Broca's formula) versus 30 with body weight < 120% of the standard to test the effect of the obesity. 1) The lightwand was bent at 20 degrees, 40 degrees, 60 degrees, or 80 degrees with 0 cm extruded from the endotracheal tube; 2) the lightwand was exposed from the endotracheal tube with -0.5, 0, 1, 2, 3, or 4 cm with 40 degrees angle; and 3) the effect of obesity was tested with 40 degrees angle and 0-cm extrusion. Endotracheal intubation was performed using the lightwand. Transillumination of the light at neck and the difficulty of intubation were assessed.

MEASUREMENTS AND MAIN RESULTS

1) A 20 degrees angle decreased the transillumination and an 80 degrees angle increased the number of difficult intubation. 2) Transillumination decreased with -0.5 cm and 0 cm extrusion. Difficult intubation increased with the extrusion > or = 3 cm. 3) Transillumination decreased and difficult intubation increased in the patients with body weight > or = 120% of the standard.

CONCLUSIONS

To increase the success rate of tracheal intubation using the lightwand, the lightwand should be bent in 40 degrees to 60 degrees, with the extrusion of 1 to 2 cm from the tracheal tube. For obese patients with body weight > or = 120% of the standard, the lightwand was not useful.

Continuous epidural administration of midazolam and bupivacaine for postoperative analgesia

BACKGROUND

Midazolam has been reported to have a spinally mediated analgesic effect. Clinically, single-shot epidural or spinal administration of midazolam has been shown to have an analgesic effect on perioperative pain. In this study, we investigated the analgesic effect of continuous epidural administration of midazolam with bupivacaine on postoperative pain.

METHODS

Four groups of 20 patients who underwent gastrectomy or cholecystectomy were studied. Continuous epidural infusion of bupivacaine 100 mg (Group C), bupivacaine 100 mg + midazolam 10 mg (Group M10), or bupivacaine 100 mg + midazolam 20 mg (Group M20) in 40 ml per 12 h was started after surgery using the balloon infuser. Group I received intermittent epidural bupivacaine (2.5 mg.ml-1) 6 ml every 2 h. When necessary, an indomethacin suppository and then a single epidural shot of bupivacaine (2.5 mg.ml-1) 6 ml was administered. Blood pressure, heart rate, respiratory rate, analgesic area, analgesia score, and sedation score were monitored for 12 h postoperatively. Memory and frequencies of supplemental analgesia (indomethacin suppositories and epidural bupivacaine) were also checked.

RESULTS

Group M20 showed a significantly wider area of pinprick analgesia and better analgesia scores than other groups. The need for rescue analgesics were significantly less in Group M20. Sedation and amnesia were more pronounced in Group M20 than the other groups.

CONCLUSION

Adding midazolam (10 to 20 mg per 12 h) to continuous epidural infusion of bupivacaine for postoperative pain can provide a better analgesia, amnesia and sedation than bupivacaine alone.

[Anesthetic management of a patient with Saber-sheath trachea]

A 65-year-old man was scheduled for total gastrectomy. Preoperative chest radiograph showed significant narrowing of the trachea. On chest CT scan the trachea was U-shaped (tracheal index = 36%) and was diagnosed as saber-sheath trachea. During general anesthesia we took care to reduce the irritation by the endotracheal tube, particularly during intubation, and to avoid excessively high airway pressure. The trachea was watched carefully by bronchoscopy after intubation and during extubation not to neglect any complication. There was no complication after the operation.

Gas embolism during hysteroscopy

PURPOSE

Gas embolism during hysteroscopy is rare but sometimes fatal. A fatal case of gas embolism during diagnostic hysteroscopy using carbon dioxide (CO2) is presented.

CLINICAL FEATURES

A 68 yr old woman was admitted for treatment of myoma and cancer of the uterus. Hysteroscopy using CO2 was performed without monitoring or anesthesia on the ward. At the end of the examination, just after the hysteroscope was removed, she developed tonic convulsions, lost consciousness, and her pulse was impalpable. Cardiac massage was started, anesthesiologists were called and the trachea was intubated. She was transferred to the intensive care unit with continuous cardiac massage. Cardiac resuscitation was successful. A central venous line was inserted into the right ventricle under echocardiography in an attempt to aspirate gas with the patient in the Trendelenberg position, but the aspiration failed. Positive end expiratory pressure and heparin for emboli, midazolam for brain protection, and catecholamines were administered. Fifteen hours after resuscitation, the pupils were enlarged and she died 25 hr after resuscitation.

CONCLUSION

Gas embolism is a rare complication of hysteroscopy. The procedure should be performed with monitoring of blood pressure, heart rate, oxygen saturation and end-tidal CO2 concentration.

[Success rate of anesthesia induction using target-controlled infusion of propofol with fentanyl]

Twenty-one patients were studied to compare the success rate of anesthesia induction using target-controlled infusion of propofol with and without fentanyl. All patients were premedicated with atropine 0.5 mg and hydroxyzine 25-50 mg. Five minutes after intravenous administration of fentanyl 2 micrograms.kg-1, patients were given infusions of propofol designed to achieve target blood concentrations of 3 micrograms.kg-1. Loss of verbal contact was regarded as successful induction. The success rate of anesthesia induction within three minutes of achieving the target concentration was 90%. Pain on injection and reduction in blood pressure were infrequent. Selecting a target concentration of 3 micrograms.kg-1 with fentanyl 2 micrograms.kg-1 can be expected to successfully induce anesthesia in the majority of patients without major hemodynamic side effects and pain on injection.

Effects of sevoflurane and isoflurane anesthesia on arterial ketone body ratio and liver function

BACKGROUND

The purpose of this study was to compare the effect on arterial ketone body ratio (AKBR), which indicates hepatic mitochondrial energy charge in relation to hepatic blood flow, and liver function test (serum levels of liver enzymes) between sevoflurane and isoflurane anesthesia.

METHODS

Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBil), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GTP), and lactate dehydrogenase (LDH) were measured before and 1,2,3,7, and 14 days after anesthesia in each of 60 patients receiving either sevoflurane or isoflurane anesthesia for neurosurgery (tumor resection). In 13 patients of both groups, arterial concentrations of acetoacetate and 3-hydroxybutyrate were also measured before, during and after (up to 12 h) anesthesia and the AKBR was calculated.

RESULTS

AST, ALT and GTP increased, peaking 7 days after anesthesia, especially in the isoflurane group. There was a significantly greater number of patients with abnormal AST and ALT values in the isoflurane group than in the sevoflurane group. The increase of TBil had its peak 1 day after anesthesia in both groups. AKBR decreased after anesthesia induction and recovered to the control value 12 h after anesthesia in both groups. There was no difference between the two anesthetic groups in AKBR.

CONCLUSION

Isoflurane induced an elevation of serum levels of liver enzymes more frequently than did sevoflurane 3 to 14 days after anesthesia, while AKBR until 12 h after anesthesia did not show any significant difference between sevoflurane and isoflurane anesthesia.

alpha1-syntrophin gene disruption results in the absence of neuronal-type nitric-oxide synthase at the sarcolemma but does not induce muscle degeneration

alpha1-Syntrophin is a member of the family of dystrophin-associated proteins and is strongly expressed in the sarcolemma and the neuromuscular junctions. All three syntrophin isoforms have a PDZ domain that appears to participate in protein-protein interactions at the plasma membrane. alpha1-Syntrophin has additionally been shown to associate with neuronal nitric-oxide synthase (nNOS) through PDZ domains in vitro. These observations suggest that alpha1-syntrophin may work as a modular adaptor protein that can link nNOS or other signaling enzyme to the sarcolemmal dystrophin complex. In the sarcolemma, nNOS regulates the homeostasis of reactive free radical species and may contribute to the oxidative damage to muscle protein in muscle disease such as Duchenne muscular dystrophy. In this study, we generated alpha1-syntrophin knock-out mice to clarify the interaction between alpha1-syntrophin and nNOS in the skeletal muscle. We observed that nNOS, normally expressed in the sarcolemma, was largely absent from the sarcolemma, but considerably remained in the cytosol of the knock-out mice. Even though the distribution of nNOS was altered, the knock-out mice displayed no gross histological changes in the skeletal muscle. We also discovered that muscle contractile properties have not been influenced in the knock-out mice.

[Dorsal root identification using spinal endoscopy and electro-physiology]

We aimed to develop a method of accurately identifying the dorsal root for the corresponding peripheral afferent nerve under endoscopic observation. We developed an endoscope with an external diameter of 1.8 mm. After small laminectomy on the lower thoracic vertebrae, we inserted this endoscope carefully into the epidural and then subarachnoid spaces. We observed structures in these spaces with the endoscope. We tried to determine the spatial relationship between these electrodes and dorsal root. After identifying each space, we inserted two electrodes into the visualized space to record evoked potentials; a bipolar electrode (protocol 1) and a catheter-type eight polar electrode (protocol 2). Each pole could be distinguished by marks. To stimulate peripheral nerves, we inserted needle-type electrodes into Th 10, 11 and 12 intercostal nerves. We attempted to record potentials from dorsal surface of the cord generated by intercostal nerve stimulus. Protocol 1: We moved the position of the bipolar recording electrodes between Th 9 and L 1 by 1 cm increment, and obtained evoked potentials correspondingly. Protocol 2: We chose the neighboring pairs of poles sequentially from the tip of the catheter for bipolar recording. At the end of each experiment, we dissected the animal and checked the intercostal nerve originating from the root. With the endoscope, we could clearly observe structures in the epidural and subarachnoid spaces. We could record evoked potentials from the dorsal spinal cord with the electrodes located either in epidural or in subarachnoid spaces. Shapes of evoked potentials changed characteristically according to the relative position between the root and the electrode. The largest potentials were obtained when the electrode was nearest to the dorsal root, of which the peripheral nerve was being stimulated. By combining endoscopy with the electrophysiological technique, we could accurately identify the dorsal roots for the corresponding peripheral afferent nerves. This method may be used for the selective dorsal root blockade under the visual field.