Peripheral nerve conduction abnormalities precede morphological alterations in an experimental rat model of sepsis

PURPOSE

The pathological mechanisms of critical illness polyneuropathy (CIP), an acute neuromuscular disorder, remain unknown. In this study, we evaluated nerve and vascular properties that might account for electrophysiological abnormalities, including reduced nerve conduction amplitude, in the early phase of CIP.

METHODS

Rats were administered intravenous saline (C-group; n = 31) or lipopolysaccharide (3 mg/kg/day; L-group; n = 30) for 48 h. Subsequently, tracheotomy was performed and sciatic nerves exposed bilaterally. A catheter was inserted into the left internal carotid artery to measure the mean arterial pressure (MAP). Nerve conduction velocity (NCV), nerve blood flow (NBF), evoked amplitudes, chronaxie, rheobase, and the absolute refractory period (ARP) were measured from the sciatic nerves. Degeneration, myelination, and neutrophil infiltration were examined in the sciatic nerves using histology and electron microscopy.

RESULTS

The NBF (C-group 25 ± 3 ml/100 g/min, L-group 13 ± 3 ml/100 g/min, p < 0.001) was lower in the L-group, but the MAP was similar between groups (C-group 119 ± 17 mmHg, L-group 115 ± 18 mmHg, p = 0.773). LPS also caused a severe reduction in amplitude (C-group 0.9 ± 0.2 mV, L-group 0.2 ± 0.1 mV, p < 0.001), while latency and NCV were not affected. Of note, response amplitudes partially recovered with an increase in stimulus intensity. LPS treatment increased the rheobase and decreased the chronaxie (rheobase: C vs L-group; 0.35 ± 0.07 vs 1.29 ± 0.66 mA, p < 0.001; chronaxie 171 ± 24 vs 42 ± 20 µs, p < 0.001), while ARP was unchanged. No primary axonal degeneration or inflammatory infiltration was observed.

CONCLUSIONS

Our findings suggest that primary electrophysiological deterioration is due to threshold alterations rather than morphological alterations after 48 h of LPS treatment.

[Two Cases of Retained Guide Wires after Placement of a Central Venous Catheter via the Internal Jugular Vein]

We report two cases of a retained guide wire after perioperative placement of a central venous catheter during a six-month period. Case 1: A 73-year-old male was scheduled for an open cholecystectomy and hepatectomy. After induction of anesthesia, a central venous (CV) catheter was inserted via the right internal jugular vein using an ultrasound guide. Chest radiographs showed a retained guide wire in the inferior vena cava immediately after surgery, which was removed by interventional radiologist before the patient emerged from anesthesia. Case 2: A 77-year-old male was scheduled for colostomy closure. The surgeon inserted a CV catheter in the right internal jugular vein 4 days before the colostomy. Chest radiographs revealed a retained guide wire in the inferior vena cava, which was removed by interventional radiologists before the patient emerged from anesthesia. Although a retained guide wire is a rare complication, awareness of this mishap is necessary to prevent it from happening.

[Case of neuroleptic malignant syndrome following open heart surgery for thoracic aortic aneurysm with parkinson's disease]

An 80-year-old woman with Parkinson's disease was scheduled for open heart surgery to repair thoracic aortic aneurysm. Parkinson's symptoms were normally treated using oral levodopa (200 mg), selegiline-hydrochloride (5 mg), bromocriptine-mesilate (2 mg), and amantadine-hydrochloride (200 mg) daily. On the day before surgery, levodopa 50mg was infused intravenously. Another 25 mg of levodopa was infused immediately after surgery. Twenty hours later, the patient developed tremors, heyperventilation, but no obvious muscle rigidity. Two days after surgery, the patient exhibited high fever, hydropoiesis, elevated creatine kinase, and a rise in blood leukocytes. She was diagnosed with neuroleptic malignant syndrome. She was intubated, and received dantrolene sodium. Symptoms of neuroleptic malignant syndrome disappeared on the fourth postoperative day. The stress of open heart surgery, specifically extracorporeal circulation and concomitant dilution of levodopa, triggered neuroleptic malignant syndrome in this patient. Parkinson's patients require higher doses of levodopa prior to surgery to compensate and prevent neuroleptic malignant syndrome after surgery.

[Unexpectedly complicated laryngoscopy caused by a massive mandibular tori]

Here, we report a case of an unexpectedly complicated laryngoscopy caused by massive mandibular tori. A 64-year-old man with mitral regurgitation and aortic regurgitation was scheduled for a double valve replacement. Thyromental distance and the Mallampati score were used as predictive factors of difficult intubation, and both factors were within the normal range. Anesthesia with controlled ventilation was started with fentanyl, propofol and vecuronium. After the attainment of full muscle relaxation, an experienced anesthesiologist performed direct laryngoscopy. It was not possible to intubate the patient under direct laryngoscopy because of massive mandibular tori which had not been detected prior to induction. Following the failure of direct laryngoscopy, a McCoy laryngoscope and a gum elastic bougie were deployed to improve vision. Intubation with a 7.5 mm tube was successful at the third attempt. We hope our experience will serve as a reminder to clinicians that mandibular tori, although benign and without subjective symptoms, could have significant effects upon direct laryngoscopy by compromising the line of vision. Preoperative oral evaluation is critical and aggressive treatment should be considered.

[Case of abdominal compartment syndrome (ACS) associated with perforating appendicitis]

A 4-year-old girl with perforating appendicitis developed abdominal compartment syndrome (ACS). Appendicitis in children of preschool age is highly likely to rupture, resulting in serious condition. Although we gave priority to systemic management in this ACS case since the child showed disturbed consciousness due to intracranial hypertension as well as hypercytokinemic encephalopathy. However, we should have performed abdominal decompression by laparotomy early. ACS causes progressive multiple organ failure through compromising the respiratory and circulatory systems and injuring multiple organs, leading to generalized inflammatory reactions. We should, therefore, manage ACS patients systemically sharing a notion that they must be treated early with abdominal decompression by laparotomy.

[Effect on fetal umbilical arterial blood of administration of vasopressors for hypotension after spinal anesthesia during cesarean section]

Spinal anesthesia was performed in 40 patients undergoing cesarean section. When systolic blood pressure dropped below 100 mmHg, phenylephrine 100-200 microg (P group) or ephedrine 5-10 mg (E group) was administered. The pH of the umbilical arterial blood was collected after delivery of the baby. Apgar scores, and maternal systolic blood pressure and heart rate before and after each drug administration were compared retrospectively. The umbilical arterial pH and Apgar scores tended to be slightly higher in the P group, but there was no significant difference between the two groups. The rate of blood pressure elevation was 27% in the P group and 41% in the E group. The heart rate decreased significantly in the P group. There was no significant difference in the systolic blood pressure before administration of each drug. Recently, it is reported that the umbilical arterial pH is higher in cases in which phenylephrine is used for hypotension after spinal anesthesia during a cesarean section. However, the optimal dose of phenylephrine is debatable and has not been established. More studies are necessary to determine which drugs should be selected according to the maternal condition.

[A case of congenital aqueductal stenosis from CT images taken for the differential diagnosis of a post-dural puncture headache]

We detected congenital aqueductal stenosis from CT images taken for the differential diagnosis of a post-dural puncture headache. A history of multiple spinal taps for anesthesia and the nature of headaches led us to a suspected diagnosis of headache caused by intracranial hypotension at variance with image findings diagnostic of hydrocephalus, perplexing us in the differential diagnosis. Hydrocephalus was of congenital type, having no causal relationship with past multiple spinal taps. Congenital aqueductal stenosis varies in severity from infancy-onset one to accidental one diagnosed from images like the current case. Since treatment may differ between hydrocephalus and intracranial hypotension which are diametrically opposite to each other in pathophysiology, it is essential to differentiate a headache in an overall view of a history, physical examination, and image findings.

[Anesthetic management with remifentanil for tracheobronchial stent insertion]

BACKGROUND

Although remifentanil produces respiratory depression, its very short duration of action provides a great advantage for the control of hemodynamics during anesthesia for tracheobronchial stent insertion. We compared remifentanil with fentanyl during propofol-based anesthesea for anesthetic management for tracheobronchial stent insertion.

METHODS

Seventy-eight patients were analyzed retrospectively by anesthetic chart review. Thirty-nine patients were anesthetized with bolus infusion of fentanyl with propofol (group PF). The remaining 39 patients were anesthetized with continuous infusion of remifentanil with propofol (group PR). Demographic data, duration of anesthesia and operative procedure, airway management, duration of emergence, dose of propofol, fentanyl and remifentanil, and use of cardiovascular drug were analyzed for the 2 groups. Chi-square tests and Student-t test were used for statistical analysis. Differences were considered significant when P was below 0.05.

RESULTS

The dose of propofol was less in the PR group than in the PF group (0.10 +/- 0.04 mg x kg(-1) x min(-1) vs. 0.14 +/- 0.04 mg x kg(-1) x min(-1), P = 0.025). The duration of emergence was shorter in the PR group than in the PF group (9.0 +/- 6.8 min vs. 12.5 +/- 6.2 min).

CONCLUSIONS

We conclude that the continuous infusion of low dose remifentanil with propofol produce more efficient respiratory and hemodynamic stability than the bolus infusion of fentanyl with propofol during anesthesia for tracheobronchial stent insertion.

[Case of neurocardiogenic syncope with asystole during insertion of epidural catheter]

A 25-year-old healthy woman was scheduled for enucleatic myomectomy under combined epidural and general anesthesia. During insertion of a lumbar epidural catheter, sudden loss of consciousness associated with asystole developed. This condition was quickly restored by rapid fluid infusion, administration of atropine sulfate (0.5 mg) and oxygen (6l x min(-1)). Diagnosis of neurocardiogenic syncope (NCS) was made by previous episodes of fainting revealed at that point. An epidural catheter was placed under sedation with midazolam 2 mg. Surgery was performed uneventfully under sevoflurane anesthesia. Since NCS occurs recurrently in a susceptible individual, it is important to identify previous syncopal episode preoperatively. If such an event is anticipated, prevention including proper communication to reduce patient's anxiety, careful vigilance on both patient and monitor during procedure, gentle maneuver to reduce pain and use sedative and/or anticholinergic agents must be considered.

[Effect of remifentanil on urine output during gynecological laparoscopic surgery]

BACKGROUND

We retrospectively examined the effect of remifentanil on urine output during gynecological laparoscopic surgery under general anesthesia performed from April 2006 to July 2007.

METHODS

Forty six patients undergoing gynecological laparoscopic surgery under general anesthesia were divided into 2 groups. In group C (n=23), anesthesia was performed using sevoflurane and/or propofol with intermittent fentanyl. In group R (n=23), remifentanil was additionally used with the method of group C.

RESULTS

Patient's demography was not different between the two groups. Intraoperative conditions were compatible in both groups. In group R, total dose of fentanyl is significantly lower than group C. BP and HR measured at 20 min after pneumoperitoneum were significantly lower in group R. Intraoperative urine output was significantly greater in group R than group C.

CONCLUSIONS

A decrease in urine output is commonly seen particularly in laparoscopic surgery. Increased stress hormonal responses due to pneumoperitoneum have been explained as one of the causes of this phenomenon. Remifentanil has been reported to maintain urine output as well as to blunt hormonal responses in CABG surgery. Although we did not measure hormonal responses in the present study, increased urine output could be attributed to decreased catecholamine levels by remifentanil.

[Anesthetic management of concomitant off-pump coronary artery bypass grafting and complete pneumonectomy for lung cancer]

A 69-year-old man was scheduled for combined surgery involving off-pump coronary artery bypass grafting (OPCABG) for coronary stenosis and total pneumonectomy for lung cancer. Anesthesia was maintained with fentanyl, thiopental, sevoflurane, nitrous oxide, and epidural anesthesia using 1.0% mepivacaine. Although a steady hemodynamic circulation was maintained during OPCABG, it was difficult to stabilize the circulation during the total pneumonectomy.

[Case of exostosis of the hard palate disturbing the insertion of Pro-Seal laryngeal mask]

We report a case of exostosis of the hard palate which had not bean ruled out in pre-operative examination and disturbed insertion of Pro-Seal laryngeal mask. The hard palate has canopy construction, and it is difficult to find this exostosis by routine physical examination. When we use Pro-Seal laryngeal mask, a careful inspection of the hard palate is indispensable.

[Case of laparoscopic cholecystectomy in a patient with glucose-6-dehydrogenase deficiency]

We report management of anesthesia in a patient suffering from glucose-6-phosphate dehydrogenase (G6PD) deficiency, a condition that induces acute hemolysis when associated with surgical stress and infection, or following the application of oxidant drugs. A 5 year-old-male patient, suffering from G6PD deficiency was scheduled for laparoscopic cholecystectomy. The patient had exhibited signs of hemolysis during the course of various infections and after ingesting fava beans (favism). Anesthesia was induced with midazolam and vecuronium and maintained with nitrous oxide in oxygen and sevoflurane. There was no hemolytic change during the perioperative period. It was clear that this combination of drugs provided safe anesthesia for the G6PD patient in the present study. The most important considerations for patients with G6PD deficiency is firstly, the avoidance of oxidative stress, which can be caused by a variety of different conditions, and secondly, the use of anti-oxidative anesthetic drugs.

[Anesthetic management for cesarean delivery in a patient with May-Hegglin anomaly]

May-Hegglin anomaly (MHA) is a rare hereditary disorder characterized by thrombocytopenia and giant thrombocytes and continuous appearance of inclusion bodies (Dohle like corpuscles) in the cytoplasm of granulocytes. A 26-year-old woman with MHA underwent cesarean delivery under general anesthesia, although she had no history of bleeding. The platelet count was 4.9x10(4) microgl(-1) the day before surgery. There was no unusual bleeding during and after the operation and we did not give her platelet transfusion.

Inhibitory effect of alprostadil against sevoflurane-induced myometrial relaxation in rats

PURPOSE

For anesthetic management of cesarean sections, regardless of the use of regional or general anesthesia, it is crucial to achieve sufficient uterine contraction immediately following the delivery of an infant in order to reduce excessive bleeding. No previous study has investigated the ability of alprostadil, a synthesized prostaglandin, to inhibit myometrial relaxation induced by volatile anesthetics. The aim of the present study was to investigate the inhibitory effects of alprostadil on sevoflurane-induced myometrial relaxation using myometrial strips isolated from pregnant rats.

METHODS

Myometrial strips were isolated from Sprague-Dawley rats (300-400 g) in the late stage of gestation (19-21 days). The time course of changes in spontaneous myometrium contraction was studied in the presence and absence of sevoflurane. Additionally, alprostadil was titrated at three different concentrations during continuous introduction of sevoflurane 2%, and myometrium contraction was studied. As an index of contraction, the area under the contraction curve was used, and data were analyzed by repeated measure one-way analysis of variance.

RESULTS

We have shown a significant decrease in myometrium contraction as a result of the use of sevoflurane (2%). Additionally, alprostadil has been shown to inhibit myometrial relaxation induced by sevoflurane in a dose-dependent manner. The areas under the contraction curve were 87%, 87%, 129%, and 172% of the baseline value for the control and at low, medium, and high concentrations of alprostadil, respectively.

CONCLUSION

The ability of alprostadil to inhibit myometrial relaxation induced by sevoflurane suggests that the use of alprostadil during general anesthesia for cesarean section may be advantageous for the reduction of postpartum bleeding.

[Anesthetic management in ten cases for tracheobronchial Dumon stent placement]

BACKGROUND

To determine perioperative complications, we evaluate herein 10 cases of anesthetic management for placement of Dumon stent in patient with tracheal or bronchial stenosis due to invasion of esophageal or lung cancer.

METHODS

After sufficient oxygenation, anesthesia was induced with propofol and fentanyl. Since muscle relaxant has been considered safe for central-type air way stenosis except for cases involving large anterior mediastinal masses, we administered vecuronium for all cases to facilitate insertion of rigid bronchoscope and for surgical procedures. Anesthesia was maintained with continuous infusion of propofol, and ventilation was performed via a side-port of a rigid bronchoscope with 100% oxygen. Extra corporeal circulation was instituted in 2 cases.

RESULTS

In 5 of the 10 cases, stent placement was uneventful. However, in the other 5 cases, respiratory failure (SpO2 < 90% and/or PaCO2 > 80 mmHg: 4 cases) or severe hypotension (systolic blood pressure < 60 mmHg: 3 cases) developed. Severe hypotension was attributed to relatively higher dose of anesthetic agents for cachexic status, or reduction in venous return following over-inflation of the lungs. Acute reduction in blood carbon dioxide levels due to extracorporeal circulation (case 4), and loss of consciousness after administration of anesthetic agents (case 2) could also have been involved in 2 cases.

CONCLUSIONS

Circulatory status must be closely monitored during anesthetic management for Dumon stent placement.

Comparison between a disposable and an electronic PCA device for labor epidural analgesia

PURPOSE

The aims of the present study were (1) to investigate if a disposable patient-controlled analgesia (PCA) device can be used for labor analgesia and (2) to evaluate the device by midwives and parturients.

METHODS

Forty healthy parturients were divided into two groups and received combined spinal epidural analgesia for labor pain relief. Following intrathecal administration of 3 mg ropivacaine and 1.5 microg sufentanil, either a disposable PCA device (Coopdech Syrinjector; Daiken Medical, Osaka, Japan) or an electronic PCA device (IVAC PCAM PCA Syringe Pump; Alaris, Basingstoke, UK) was connected to the epidural catheter, and 0.15% ropivacaine with sufentanil 0.75 microg/ml was used for continuous infusion and PCA. For an electronic PCA device, continuous infusion rate, bolus dose, lockout time, and hourly limit were set at 4 ml/h, 3 ml, 15 min, and 16 ml, respectively. For a disposable PCA device, continuous infusion rate, bolus dose, and an hourly limit were set at 4 ml/h, 3 ml, and 16 ml, respectively, but lockout function was not available.

RESULTS

No differences were observed between the groups concerning demographic data, obstetric data, and outcome of labor. Anesthetic requirements (disposable, 9.7 +/- 4.7 ml/h; electronic, 8.2 +/- 4.0 ml/h) and VAS score during the delivery (disposable, 26 +/- 25; electronic, 21 +/- 22) were similar between the groups. Midwives praised the disposable PCA device as well as the electronic one.

CONCLUSION

The present results imply that the disposable PCA device can be an alternative to the electronic PCA device for labor analgesia.

[Anesthetic management for cesarean section in a patient with hydrops foetalis]

In cases of hydrops foetalis, respiratory management is frequently required after delivery. We experienced 7 anesthetic managements for cesarean section in patients with hydrops foetalis. Spinal anesthesia was performed in 3 patients, because the transition of local anesthesia through the placenta was little. On the other hand, general anesthesia was performed in 4 patients because of babies requiring endotracheal intubation or fetal anesthesia immediately after a delivery. Before surgery, we discussed perioperative and anesthetic management among pediatricians, pediatric surgeons, and obstetricians in a conference. Since the anesthetic drugs used for the cesarean section have great influences on the fetus, the choice of anesthesia should be performed based on fetal conditions.

[Brachial plexus neuropathy following open-heart surgery]

A 64-year-old woman underwent open-heart surgery for repair of atrial septal defect (ASD) and tricuspid valve regurgitation. Preoperative complications included rheumatoid arthritis with pain in both wrists treated with methotrexate. Following smooth endotrachial intubation, a pulmonary arterial (PA) catheter was inserted into the right jugular vein after several attempts. She was placed in a supine position with abduction of the shoulders to approximately 90 degrees and of the elbows to 60 degrees. Operation was performed through sternum splitting to second intercostal space, and the 4-h intraoperative course was uneventful. On the first postoperative day, she complained of inability to raise her right arm. Neurological examination revealed marked weakness of the deltoid and biceps brachialis muscles, and decreased sensitivity around the right shoulder. Iatrogenic brachial plexus injury was diagnosed. Administration of vitamin B12 and physical therapy were instituted. Symptoms improved gradually and had disappeared by 3 months postoperatively. Neuropathy might be attributed to stretch and compression of the brachial plexus caused by traction of the pectoralis minor muscle enhanced by sternotomy and/or malposition of the upper extremity, or direct injury due to cannulation of the PA catheter into the internal jugular vein.

[The effect of repeated sevoflurane anesthesia on hepatic function and immunological system]

BACKGROUND

Sevoflurane is known as a useful and safe anesthetic because of its properties of fast uptake and elimination at the lungs and of no effects on hepatic function. In this study we examined the effect of repeated sevoflurane anesthesia on hepatic function and immunological system.

METHODS

Eight patients (ASA, PS 2 or 3) received sevoflurane anesthesia three times in 6 months. Six patients had emergency operation for injuries. Aspirate transaminase (AST), alanine transaminase (ALT) and complements (CH50, C3, C4) were measured prior to anesthesia, and 1, 7 and 14 days after anesthesia.

RESULTS

The values of AST and ALT were high prior to anesthesia at the first anesthesia. However, these were of no significant changes. CH50, C3, C4 increased significantly after the first anesthesia. However, there were no significant changes of these complements after the second and the third anesthesia.

CONCLUSIONS

Our results suggest that sevoflurane is not likely to provide adverse effects on the liver and to suppress the production of complements accompanied by the surgical stress.

Hypothetical mechanism of prostaglandin E1-induced bronchoconstriction

In general, prostaglandin E1 (PGE1) is thought to relax smooth muscles in the airway and to inhibit muscle constriction. We hypothesized that, under the specific conditions, PGE1 induces bronchoconstriction, resulting in the promotion of inflammation. Examples of the specific conditions where this mechanism may occur include cases where patient who are susceptible to inflammation receive a continuous infusion of PGE1 during induced hypotension or during treatment for intraoperatively abnormal hypertension.

[Anesthetic management of a pediatric patient with a laryngeal foreign body]

Laryngeal foreign bodies in children are less common than bronchial foreign bodies, but are more dangerous. We report an 8-month-old boy who accidentally inhaled an open safety pin into his larynx. Anesthesia was induced and maintained with sevoflurane, oxygen. No muscle relaxant was administered during operation. The open safety pin was removed with Jackson's esophagoscope. No complications were observed during the operation.

[Anesthetic management of a patient with Young-Simpson syndrome]

Young-Simpson syndrome (YSS) is a rare malformation syndrome characterized peculiar facies, congenital hypothyroidism, congenital heart disease, and postnatal growth deficiency. A 3-year-old boy with YSS underwent tracheostomy for respiratory failure under general anesthesia using sevoflurane, nitrous oxide and oxygen. Although he was assumed to be difficult for intubation due to micrognathia and macroglossia, tracheal intubation was done without difficulty. No complications were observed during the 40 minutes of the operation.

Novel mechanism of action hypothesized for stellate ganglion block related to melatonin

The mechanism of action of stellate ganglion block has generally been explained by vasodilation within its sphere of innervation. However, the success of treatment cannot always be explained by just one mechanism of action, because its clinical indications in Japan extend to many diseases, including systemic diseases. We propose a new mechanism of action for stellate ganglion block that is based on correction of melatonin rhythm disorder resulting from increased sympathetic nerve tone and does not involve vasodilation.

[Two cases of intraoperative cerebral hemorrhage caused by undiagnosed metastatic brain tumors]

The authors report two cases of intraoperative cerebral hemorrhage caused by metastatic brain tumors. Delayed recovery from general anesthesia and neurological deficit were found in these patients. Brain CT in case 1 showed bilateral subdural hemorrhage and parenchymal massive hemorrhage in case 2. It is thought that the causes of hemorrhage are due to the changes in morphology of vessels, deterioration in cerebral circulatory regulated system, and increased intracranial pressure caused by tumors. Since the incidence of metastatic brain tumor has increased with prolonged survival time induced by progress in cancer therapy, preoperative brain examination and careful attention to vital signs during anesthesia are needed.

[The effects of midazolam on the memory of pain]

The purpose of this study was to evaluate the effects of low dose midazolam (MZ) on memories of spinal puncture. The low doses of MZ were administered to 70 patients (ASA 1-2), of whom 37 patients were premedicated with atropine sulfate 0.5 mg and pethidine hydrochloride i.m. (group P), and 33 patients received no premedication (group N). Double blind randomized trials were conducted with the doses of MZ (0, 0.03, 0.06 mg.kg-1), and MZ was administered i.v. to the patients just prior to spinal puncture. Subjective evaluation of pain was performed with pain score (PS) on postoperative phase, and objective evaluation of pain was performed with the reaction of spinal puncture. Short term memory was impaired mainly after administration of MZ. However, subjective memory of pain almost disappeared, but objective evaluation was not so good. We conclude that MZ induces impairment to recall of pain. However, it might maintain the response to the pain.

[The use of low dose midazolam for the management of spinal anesthesia]

The purpose of this study was to evaluate the effects of low dose midazolam (MZ) on memories and ease of management of spinal anesthesia. The low doses of MZ were administered to 70 patients (ASA 1-2), of whom 37 patients were premedicated with atropine sulfate 0.5 mg and pethidine hydrochloride (group P), with 33 patients receiving no premedication (group N). Double blind randomized trials were conducted with the doses of MZ (0, 0.03, 0.06 mg.kg-1), and MZ was administered i.v. to patients just prior to spinal puncture. The short-term and long-term memories were impaired after administration of MZ in both groups. We conclude that MZ appears to be a suitable replacement for other benzodiazepines for relieving anxiety of patients during surgery.

[The use of low dose midazolam for the management of spinal anesthesia]

The present study was designed to evaluate the effects of low dose midazolam (MZ) on memories and ease of management of spinal anesthesia. MZ was administered to 103 patients (ASA 1-2), of whom 50 patients were premedicated with atropine sulfate 0.5mg and pethidine hydrochloride (group P), with 53 patients receiving no premedication (group nP). A double blind randomized trial was conducted with the dose of MZ (0, 0.01, 0.02, 0.04, 0.08 mg.kg-1), and MZ was administered i.v. to patients just prior to spinal puncture. The short-term and long-term memories were impaired after administration of MZ in both groups. But the recovery from impairment of memories was more rapid in the short-term memory than in the long-term memory, suggesting that MZ impairs mainly the acquisition of memories. A dose-dependent decrease in SpO2 was observed in group P. We conclude that MZ is a useful drug to relieve anxiety of patients during surgery, but it accompanies the risk of respiratory depression.

[The use of a laryngeal mask in a newborn infant with Nager acrofacial dysostosis]

A newborn female infant born at 41 week gestation with Nager acrofacial dysostosis had no congenital abnormalities in her parents and closed relatives. Her mother had uncomplicated pregnancy and normal delivery. Endotracheal intubation was attempted, because she developed apnea on her delivery, but it was not successful. She was transported immediately to our university hospital with mask ventilation. A laryngeal mask was placed after several trials of intubation, and ventilation was carried out successfully. We consider that the use of a laryngeal mask is one of the best ways in a case of difficult intubation.