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S Sakura

Publications and source records attributed to S Sakura.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Neurologic sequelae of spinal anesthesia: local anesthetic toxicity].

Recent reports of cauda equina syndrome following continuous spinal anesthesia have generated concern regarding the safety of not only this particular technique but also of the local anesthetic agent itself. This concern has been reinforced by data suggesting that similar injuries have occurred with repeated injection after a "failed spinal", and by reports of transient radicular irritation following single subarachnoid injection. This paper summarizes the above cases and reviews recent experiments performed to determine the mechanisms underlying local anesthetic toxicity and the factors that contribute to injury. These experiments suggest that the recent injuries resulted from a direct effect of the local anesthetic and that anesthetic-induced impairment does not result from blockade of the sodium channel, per se. These experiments also suggest that development of a safer anesthetic is a realistic goal.

Anesthesia, Spinal↗
PubMed1995

Anaesthetic management for caesarean section in a patient with Kawasaki disease.

Kawasaki disease (KD) or mucocutaneous lymph node syndrome is an acute febrile illness affecting mainly children under four years of age. The most important clinical feature of this disease is coronary arteritis associated with aneurysms and thrombotic occlusions, which may lead to ischaemic heart disease or sudden death. It has now been more than 20 yr since its first description, and a number of survivors of childhood KD have reached child-bearing age. Despite the possible fatal outcome of this disease in adult patients with coronary artery manifestations, no information is available regarding the obstetrical anaesthetic management of patients with a history of KD. The purpose of this report is to describe the successful use of epidural anaesthesia in a patient with a history of KD undergoing Caesarean section and to discuss the anaesthetic considerations that should be given to adult survivors of childhood KD.

Adult↗
PubMed1995

Interaction of extradural morphine and lignocaine on ventilatory response.

We have evaluated the effects of lumbar extradural morphine and lignocaine on the ventilatory response to carbon dioxide. Twenty-four female patients were allocated randomly to receive extradural morphine 2 mg (group M), 2% lignocaine 10 ml (group L) or a combination of morphine 2 mg and 2% lignocaine 10 ml (group ML). On the day before surgery, resting ventilatory values including minute volume (VE) and tidal volume (VT), and ventilatory response to progressive hyperoxic hypercapnia (VE/PE'CO2) were measured. On the day of surgery, the same measurements were repeated 30 min after extradural injection. Ventilatory values at rest were not altered after extradural injection. Mean VE/PE'CO2 decreased significantly after extradural morphine (P = 0.002) and increased (P = 0.011) after extradural lignocaine. Mean VE 7.3 (VE at PE'CO2 7.3 kPa) decreased significantly after extradural morphine (P < 0.001) and increased after extradural lignocaine (P = 0.047). Extradural morphine and lignocaine did not significantly alter mean VE/PE'CO2 and mean VE 7.3: 14.6 (95% confidence intervals 12.1-17.1) to 15.3 (13.1-17.6) litre min-1 kPa-1 and 22.8 (18.1-27.5) to 22.8 (17.3-28.3) litre min-1, respectively. We conclude that extradural co-administration of morphine and lignocaine did not increase the risk of respiratory depression associated with morphine.

Adult↗
PubMed1995

Local anesthetic neurotoxicity does not result from blockade of voltage-gated sodium channels.

To investigate whether local anesthetic neurotoxicity results from sodium channel blockade, we compared the effects of intrathecally administered lidocaine, bupivacaine, and tetrodotoxin (TTX), the latter a highly selective sodium channel blocker, on sensory function and spinal cord morphology in a rat model. First, to determine relative anesthetic potency, 25 rats implanted with intrathecal catheters were subjected to infusions of lidocaine (n = 8), bupivacaine (n = 8), or TTX (n = 9). The three drugs produced parallel dose-effect curves that differed significantly from one another: the EC50 values for lidocaine, bupivacaine, and TTX were 28.2 mM (0.66%), 6.6 mM (0.19%), and 462 nM, respectively. Twenty-five additional rats were then given intrathecal lidocaine (n = 8), bupivacaine (n = 8), or TTX (n = 9) at concentrations 10 times the calculated EC50 for sensory block. Lidocaine and bupivacaine induced persistent sensory impairment, whereas TTX did not. Finally, 28 rats were given either intrathecal bupivacaine (n = 10) or TTX (n = 9) at 10 times the EC50, or normal saline (n = 9). Significant sensory impairment again occurred after infusion of bupivacaine, but not after infusion of TTX or saline. Neuropathologic evaluation revealed moderate to severe nerve root injury in bupivacaine-treated animals; histologic changes in TTX- and saline-treated animals were minimal, similar, and restricted to the area adjacent to the catheter. These results indicate that local anesthetic neurotoxicity does not result from blockade of the sodium channel, and suggest that development of a safer anesthetic is a realistic goal.

Animals↗
PubMed1995

The addition of 7.5% glucose does not alter the neurotoxicity of 5% lidocaine administered intrathecally in the rat.

BACKGROUND: Recent reports of major and minor neurologic sequelae after spinal anesthesia have generated concern regarding the safety of some currently used intrathecal agents. The role of glucose, if any, in neurotoxic injury associated with spinal anesthesia is not known. The current experiments sought to determine whether the presence of 7.5% glucose alters the neurotoxicity of intrathecally administered 5% lidocaine. METHODS: Two experiments were performed. First, 48 rats were implanted with an intrathecal catheter and randomly divided into eight equal groups. Each animal received a single intrathecal infusion of 5% lidocaine (groups P1-P4) or 5% lidocaine with 7.5% glucose (G1-G4) for 0.5, 1, 2, or 4 h at a rate of 1 microliter/min. Sensory function was assessed using the tail-flick test; a deficit was defined as a complete lack of response to the heat stimulus at the proximal, mid or distal portion of the tail persisting 4 days after the infusion. In the second experiment, 60 rats were randomly divided into two groups to receive a 1-h intrathecal infusion of 5% lidocaine or 5% lidocaine with 7.5% glucose. Animals were evaluated for increase in the latency of the tail-flick reflex 4 days after infusion. RESULTS: In the first experiment, the two lidocaine solutions produced similar dose-dependent loss of sensory function. In the second experiment, the two solutions induced similar alterations in tail-flick latency. CONCLUSIONS: The presence of 7.5% glucose does not affect the potential of intrathecally administered 5% lidocaine to induce sensory impairment. These findings provide further support for the hypothesis that recent injuries after spinal anesthesia resulted from a direct neurotoxic effect of the local anesthetic.

Anesthesia, Spinal↗
PubMed1994

Persistent sacral sensory deficit induced by intrathecal local anesthetic infusion in the rat.

BACKGROUND: Several cases of cauda equina syndrome after continuous spinal anesthesia have been recently reported. One possible etiology is toxic exposure of the sacral roots resulting from intrathecal maldistribution of a relatively large dose of local anesthetic. The current experiments sought to determine whether a local anesthetic solution, injected intrathecally to produce a restricted distribution of anesthesia, could result in a sacral deficit. In addition, we sought to test the hypothesis that, when equal volumes are administered intrathecally, significant differences exist in the potential to three commonly used anesthetic solutions to induce sensory impairment. METHODS: Thirty-two rats were implanted with intrathecal catheters to permit repetitive infusion of local anesthetic. Animals were randomly assigned to four groups of eight to receive either 5% lidocaine with 7.5% dextrose; 0.75% bupivacaine with 8.25% dextrose; 0.5% tetracaine with 5% dextrose; or normal saline. Each rat received, in sequence, a 1-h (60 microliters), a 2-h (120 microliters), and a 4-h (240 microliters) infusion; the infusions were separated by a 4-day rest period. Sensory function was assessed using the tail-flick test, which was performed immediately before each infusion and 6 days after the last infusion by an investigator blinded to the solution infused. RESULTS: There was no significant difference in baseline tail-flick latencies for the four groups. Tail-flick latency for the lidocaine group was significantly prolonged when compared with the bupivacaine, tetracaine, and saline groups. This difference was apparent after the first infusion and persisted throughout the study. CONCLUSIONS: In the rat, restricted anesthetic distribution can be achieved, and sensory impairment may result. These findings further support an etiology of local anesthetic neurotoxicity for recent clinical injuries after continuous spinal anesthesia. The functional model described appears to be suitable for in vivo study of local anesthetic neurotoxicity.

Anesthesia, Local↗
PubMed1993

Differences in the assessment of postoperative pain when evaluated by patients and doctors.

This study was undertaken to compare the assessment of pain intensity by 59 patients and by their doctors according to a visual analogue scale (VAS) at rest and when coughing at 5 and 20 hr after major abdominal surgery. The rating given by the patients, who received epidural analgesia to relieve postoperative pain, was significantly above, and moreover, significantly correlated with that given by the doctors at any time or under any condition of the assessment. However, the correlation between the ratings given by patients and doctors at rest at 5 hr after surgery was low (r = 0.39, rs = 0.38) and significantly different from that when coughing at 20 hr after the operation (r = 0.79, rs = 0.80). Our findings indicate that the assessment of postoperative pain may be associated with some unreliability, especially during early periods, when using the subjective or objective-rated VAS at rest separately, and thus requires the combined use or the concomitant use of the VAS when coughing. Substitutional use of the objective-rated VAS for the subjective-rated VAS is not advised.

Journal Article↗
PubMed1993

Effect of extradural anaesthesia on the ventilatory response to hypoxaemia.

The effect of lumbar or thoracic extradural anaesthesia on the ventilatory response to progressive isocapnic hypoxaemia was studied in two groups of 10 unpremedicated patients. The ventilatory measurements were taken twice, before and 20 min after the administration of 10 ml of lignocaine 2%. Lumbar extradural anaesthesia did not change the slope of the hypoxic response curve, but it significantly increased minute ventilation by 27% at an arterial oxygen saturation of 90%. Thoracic extradural anaesthesia was not associated with any changes in either index. We conclude that neither lumbar nor thoracic extradural anaesthesia impairs the ventilatory response to progressive isocapnic hypoxaemia.

Adult↗
PubMed1993

Epidural anesthesia in a patient with myasthenia gravis.

We present a patient with myasthenia gravis who was safely managed by epidural anesthesia during and after thymectomy. An epidural catheter was inserted via the C7-T1 intervertebral space and 2% lidocaine was used during the surgery. The level of analgesia as determined by pinprick extending from C5 to T6. Epidural morphine or morphine and bupivacaine were used for postoperative pain relief. We evaluated ventilatory responses to CO2 and hypoxia after epidural anesthesia with lidocaine or morphine, and during continuous epidural infusion of the mixture of morphine and bupivacaine. Ventilatory responses to CO2 and hypoxia were both depressed following epidural injection of morphine. However, depression of ventilatory responses was not demonstrated following continuous epidural infusion of a mixture of morphine and bupivacaine. This case report suggests that epidural anesthesia is useful as a primary anesthetic and for postoperative pain control in patients with myasthenia gravis.

Adolescent↗
PubMed1991

Epidural analgesia in Eaton-Lambert myasthenic syndrome. Effects on respiratory function.

The anaesthetic management of a patient with Eaton-Lambert myasthenic syndrome undergoing thoracotomy is described. Epidural anaesthesia, in combination with a light level of general anaesthesia, provided good operating conditions and postoperative analgesia. Pulmonary function and ventilatory responses to carbon dioxide and hypoxia were measured before operation. These tests were repeated after the epidural administration of 8 ml 2% lignocaine before surgery and after 2 mg morphine sulphate in 10 ml saline postoperatively. Minor reductions in some of the ventilatory parameters were observed. The epidural technique appears to be a useful and safe method by which to manage patients with Eaton-Lambert syndrome undergoing thoracotomy.

Analgesia, Epidural↗
PubMed1990

Continuous epidural infusion for postoperative pain relief: a comparison of three regimens.

We evaluated the postoperative pain relief and side-effects of continuous epidural infusion of three analgesic regimens following major thoracic and/or abdominal surgery. One hundred and twenty patients were randomly divided into three treatment groups: (1) 0.25% or 0.5% bupivacaine at a rate of 3-7 ml.hr(-1), (2) 0.01% morphine at a rate of 1-2 ml.hr(-1), (3) a combination of 0.125% or 0.25% bupivacaine and 0.0025% or 0.005% morphine at a rate of 2-4 ml.hr(-1). The study continued for the first 48 postoperative hours. The effect of pain relief was evaluated by assessment of the further requirement for parenteral analgesics. Sixty-four percent of the patients given bupivacaine, 56% of the patients given morphine and 80% of the patients given the combination required no supplemental analgesics. Continuous epidural infusion of bupivacaine was associated with hypotension (21%) and with numbness and weakness of hands or legs (18%). Continuous epidural infusion of morphine was associated with pruritus (18%) and with peristaltic depression (12%). The combination regimen was associated with pruritus (17%) and with drowsiness (14%). We conclude that the combination of bupivacaine and morphine significantly provides superior analgesia with less deleterious complications compared with either bupivacaine or morphine alone.

Clinical Trial↗
PubMed1990

Continuous epidural infusion for postoperative mechanical ventilation.

We evaluated in analgesic and sedative effects of continuous epidural infusion of two analgesic regimens in ventilated patients following esophagectomy. Forty-six patients, divided into two treatment groups, received postoperative continuous epidural infusion of morphine, or that of a combination of bupivacaine and morphine. Assessments were made with the following indices: pain relief score, somnolence score, patient ventilator coordination score, and the number of supplemental administrations of analgesics and sedatives. No significant differences occurred in somnolence scores or patient ventilator coordination scores between the two groups, which revealed satisfactory sedation for mechanical ventilation. Patients receiving the combination of bupivacaine and morphine had significantly less pain postoperatively, requiring a smaller number of supplemental administrations of analgesics and sedatives ( P < 0.05). It is concluded that: 1) continuous epidural infusion of analgesics gives potent analgesia and sedation of ventilated patients following esophagectomy; 2) the combination of bupivacaine and morphine gives pain relief superior to morphine alone.

Journal Article↗
PubMed1990

Changes in pulmonary function during continuous epidural bupivacaine with or without morphine following upper abdominal surgery.

To assess the effect of postoperative continuous thoracic epidural infusion of bupivacaine on pulmonary function, a prospective randomized study was conducted in patients undergoing upper abdominal surgery (UAS). Sixteen patients, divided into two treatment groups, received continuous epidural infusion of 0.25% bupivacaine at a rate of 2-5 ml.hr(-1), or that of a combination of 0.125% or 0.25% bupivacaine and 0.0025% or 0.005% morphine at a rate of 2-4 ml.hr(-1). One, 4, 10, 16, 24 and 40 hr postoperatively, the following indices were measured: visual analogue scale score, modified Prince Henry pain scale score, arterial Pa(O)(2) and Pa(CO)(2), functional residual capacity (FRC), and tidal volume (TV). There was no difference in pain scores between the two groups except for significantly less pain at 40 hr in the combination group. Postoperative measurements of pulmonary function revealed a significant fall in Pa(O)(2), FRC and TV, indicating a reduction of 15-25% as compared with the preoperative values, and no significant differences between the two groups. The authors conclude that postoperative continuous epidural infusion of bupivacaine combined with morphine is highly effective in alleviating pain and improving pulmonary function in patients following USA.

Clinical Trial↗
PubMed1990

[The effects of thiamylal, ketamine and nicardipine on the hippocampal theta waves produced by cerebral ischemia in cats].

Spontaneous hippocampal electroencephalogram (EEG) was recorded in the pyramidal cell layer (PCL) and dentate gyrus (DG) during and after ischemia produced by bilateral clamping of the common carotid arteries in cats. Hippocampal theta waves, approximately 180 degree out of phase in PCL and DG, appeared within 4.3 +/- 2.3 seconds after the onset of bilateral carotid artery occlusion and continued for more than 60 minute. These hippocampal theta waves disappeared 34.2 +/- 10.2 seconds after 4 vessel occlusion. We could not find the clear difference between the two areas in the appearance and disappearance of the hippocampal theta waves. We further investigated the effects of thiamylal, ketamine and nicardipine on the hippocampal theta waves during bilateral carotid artery occlusion. Thiamylal changed the two hippocampal theta waves to a similar pattern of EEG, which has irregular slow and fast waves, in both PCL and DG. Ketamine changed the two theta waves to irregular complex pattern of fast and slow waves and spike activity, which is independent at two areas. Nicardipine, a Ca antagonist, changed the theta waves to irregular slow waves which were similar to the pattern of EEG observed before carotid artery occlusion. These results indicate that thiamylal, ketamine and nicardipine have different effects on the ischemia of hippocampus.

Animals↗
PubMed1990

[Continuous epidural infusion of bupivacaine and morphine for postoperative pain relief].

Forty-five patients admitted to the intensive care unit following thoracic or abdominal surgery received continuous epidural infusion of bupivacaine and morphine for 48 hours. During the first 10 hours, the patients received 0.25% bupivacaine solution with 0.005% morphine at the rate of 4 ml.h-1, and bupivacaine concentration was decreased to 0.125% with the same morphine concentration. The mean infusion rate of bupivacaine during 48 hours was 0.12 +/- 0.03 (SD) mg.kg-1.h-1 and that of morphine was 4.0 +/- 1.0 micrograms.kg-1.h-1. Thirty-one patients (69%) complained no pain on deep breathing at 24 hours and 33 patients (74%) required no other type of analgesics during this study. The mean plasma bupivacaine concentration was 0.6 +/- 0.3 microgram.ml-1 at 48 hours. Hypotension defined as systolic arterial pressure below 90 mmHg and itching were observed in 15 patients (33%), but no other severe side effects were noted. Continuous epidural infusion of bupivacaine and morphine mixture for 48 hours postoperatively provided effective pain relief with a low incidence of side effects.

Abdomen↗
PubMed1986

Mild interaction of proteins with butyl and hydroxyl groups on the surface of polymer gels TSK HW-65 and butyl toyopearl 650-M.

Interaction of bovine serum albumin (BSA) with butyl and hydroxyl groups on adsorbent gel surfaces was investigated by using TSK HW-65 and Butyl Toyopearl 650-M gels. It was found that BSA was adsorbed on the gel not only from highly concentrated ammonium sulphate but also from dilute perchloric acid, trichloroacetic acid, etc. Some eluent modifiers, such as organic solvents (30% aqueous methanol or acetonitrile), salt solutions (0.18-0.2 M phosphate) and hydrogen-bond breaking reagents (3-7 M urea, 10 M ethylene glycol, 0.1% triethylamine) were found to be effective in facilitating the elution of trapped BSA from the gel. The conformational change of BSA in these solutions was slight except for urea, and it was reversibly recovered after removal of the modifier from the aqueous solutions, except for the hydrogen-bond breaking reagents.

Adsorption↗