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Miwako Saito

Publications and source records attributed to Miwako Saito.

6 recordsLinked to original sources

Spinal anesthesia using a continuous spinal catheter for cesarean section in a parturient with prior surgical correction of scoliosis.

This case report demonstrates the successful anesthetic management of cesarean section for a 29-year-old primiparous parturient with a past history of a scoliosis operation at 13 years of age. An Isola hook and screw-rod system had been implanted as posterior spinal instrumentation at the level of T3-L3. We titrated hyperbaric bupivacaine 7 mg combined with fentanyl 15 microg through a continuous spinal catheter, placed with a catheter-over-needle technique in order to avoid unintentional wide spread of anesthetic agents. The anesthetic level was T4 at the start of the operation. Her surgery was carried out without any problems. Headache, as a dural tap-related complication, was not observed. Spinal anesthesia with the titration of anesthetic agents for cesarean section is considered to be one of the choices for a parturient who has had spinal instrumentation.

Adult↗

Subcutaneous sumatriptan for refractory trigeminal neuralgia.

BACKGROUND: Mechanical compression of the trigeminal root by an artery is thought to cause trigeminal neuralgia. The 5-HT(1B/1D) receptor agonist may inhibit neurogenic inflammation and vasodilation near the irritated trigeminal root. OBJECTIVE: To examine the effectiveness of a 5-HT(1B/1D) receptor agonist, sumatriptan, on a paroxysmal pain in trigeminal neuralgia. METHODS: Twenty-four patients with trigeminal neuralgia refractory to previous treatment were randomized to receive subcutaneously either 3 mg (1 mL) of sumatriptan or 1 mL of saline placebo. Following a 7-day period, patients crossed over to receive the alternative treatment. Paroxysmal pain triggered by touching or moving the face was assessed with VAS before and 15 minutes after the treatment. Patients used a descriptive scale to pain-grade outcome, and asked to note whether the pain returned and how long after therapy it recurred. RESULTS: Subcutaneous sumatriptan, but not placebo, significantly decreased VAS from 8.3 +/- 2.1 to 2.4 +/- 3.0 cm (mean +/- SD). The number of patients who described their pain as moderately or slightly better was 20 in the sumatriptan group and 1 in the placebo group. The effect of subcutaneous sumatriptan persisted for a median period of 7.9 hours (range: 1-20 hours). CONCLUSIONS: Subcutaneous sumatriptan produced prompt analgesia without serious adverse reactions in patients with trigeminal neuralgia refractory to previous treatment.

Adult↗

Activities of rat cytochrome P450 3A and 2C isoforms are increased in vivo by magnesium sulfate as evidenced by enhanced oxidation of bupivacaine and testosterone in liver microsomes.

We previously reported that magnesium sulfate (MgSO(4)) increases the threshold dose of bupivacaine in inducing seizure in rats. Cytochrome P450 (P450) isoforms involved in the biotransformation of bupivacaine to three oxidative metabolites and the effects of MgSO(4) in vivo on the P450 activities in rats were investigated. Of six cDNA-expressed rat P450 isoforms tested, CYP3A2 and CYP2C11 had high rates for N-debutlylation and 3'-hydroxylation of bupivacaine, respectively. The liver microsomes prepared from male rats pretreated with intravenous administration of MgSO(4) (a bolus dose of 25 mg/kg, followed by infusion of 2.0 mg/kg/min for 6 h) showed increased V(max) values for N-debutylation and 3'-hydroxylaiton of bupivacaine compared to the liver microsomes from control rats. Administration of MgSO(4) also increased the activities of testosterone 6beta- and 16alpha-hydroxylation. Although the level of expression of CYP3A and CYP2C isoforms in the liver microsomes were unchanged, NADPH-P450 reductase and cytochrome b(5) were found to be induced by intravenous administration of MgSO(4). These results suggest that CYP3A and CYP2C isoforms are activated by MgSO(4) in vivo as a consequence of enhanced microsomal electron transfer due to induction of NADPH-P450 reductase and cytochrome b(5), leading to the increased metabolism and clearance of bupivacaine.

Anesthetics, Local↗

Patient-controlled epidural analgesia during labor using ropivacaine and fentanyl provides better maternal satisfaction with less local anesthetic requirement.

PURPOSE: To test the hypothesis that patient-controlled epidural analgesia (PCEA) using ropivacaine and fentanyl provides better maternal satisfaction and less anesthetic requirement than conventional continuous epidural infusion (CEI) during labor, we studied 58 uncomplicated parturients (singleton, vertex presentation). METHODS: After establishing effective epidural analgesia with 11 ml of 0.2% ropivacaine, all parturients were randomly divided into one of two groups: the PCEA group (n = 29) or the CEI group (n = 29). In the PCEA group, the pump was initiated to deliver a basal infusion at 6 ml x h(-1) and a demand dose of 5 ml; the lockout interval was 10 min, and there was a 31 ml x h(-1) limit. The drugs used were 0.1% ropivacaine + fentanyl 2 microg x ml(-1). In the CEI group, epidural analgesia was maintained with the same solution as the PCEA group at a constant rate of 10 ml x h(-1). If parturients requested additional analgesia in the CEI group, we added 8 ml of epidural 0.2% ropivacaine without fentanyl. RESULTS: Parturients' demographic data, such as duration of labor, mode of delivery, Apgar score, and umbilical arterial pH did not differ between the two groups. However, the hourly requirement of ropivacaine was significantly less in the PCEA group than in the CEI group (9.3 +/- 2.5 vs. 17.6 +/- 7.6 mg x h(-1); P < 0.05). Parturients' satisfaction assessed by the Visual Analogue Scale tended to be higher in the PCEA group than in the CEI group. Side effects such as nausea, hypotension, and itching were similar for the two groups. CONCLUSION: We found that PCEA was an effective means of providing optimal analgesia, with better satisfaction during labor and less local anesthetic requirement.

Adult↗

Labour analgesia guided by echocardiography in a parturient with primary dilated cardiomyopathy.

PURPOSE: To evaluate the effects of intrathecal analgesics on cardiac function during labour analgesia using echocardiography in a parturient with idiopathic dilated cardiomyopathy (DCM). CLINICAL FEATURES: Induction of labour was planned in a 35-yr-old primiparous woman suffering from DCM. In order to stabilize hemodynamics in this patient, we induced continuous spinal analgesia with an infusion of fentanyl and epinephrine. Although her analgesia was well maintained for three hours during the first stage of labour, the patient complained of pain towards the second stage of labour. At this point, we administered bupivacaine intrathecally to alleviate her pain. Transthoracic echocardiography showed that the left ventricular end-diastolic and systolic dimensions, as well as the ejection fraction were not impaired by use of these analgesic medications. CONCLUSION: Measurement of left ventricular dimensions by echocardiography allowed us to monitor the patient's response to intrathecal analgesic medications. In this patient with DCM, analgesia with intrathecal fentanyl and bupivacaine was well tolerated.

Adult↗