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Biomedical subjects

S Dohi

Publications and source records attributed to S Dohi.

At least 217 records · Page 12Linked to original sources
PubMed1983

Hemifacial spasm: a new technique of facial nerve blockade.

A new technique of facial nerve blockade using a special needle and a nerve stimulator was introduced. The results in patients suffering from hemifacial spasm are reported. This technique reduced the difficulties in identifying the facial nerve and decreased the suffering associated with the conventional way of creating these blocks. The technique described may also allow titration of neurolytic agent which may produce complete relief from spasm with much less likelihood of facial paralysis after the nerve blockade.

Adult↗
PubMed1983

Postcardiopulmonary resuscitation pulmonary edema.

Although severe pulmonary edema is encountered occasionally in patients needing CPR, there has been no definitive description on the mortality and morbidity of pulmonary edema after CPR. The author experienced severe pulmonary edema after standard CPR in 20 of 71 patients who suffered sudden, unexpected cardiac arrest and regained heart function by CPR. The varied onset of pulmonary edema, which may have developed when massive pink frothy secretions exited from the endotracheal tube, ranged from a few minutes to 45 min after the re-establishment of heart beat. These 20 patients showed a significantly higher P(A-a)O2, insignificant lower plasma protein concentrations, and high plasma osmolarities as compared with those who did not develop pulmonary edema. Only 2 patients with pulmonary edema survived. During CPR, many factors could cause pulmonary edema, including external cardiac massage (ECM), administration or release of catecholamines, hypoxia, acidosis, overhydration, etc. This study indicates that patients who need CPR have a high likelihood of developing pulmonary edema.

Adolescent↗
PubMed1983

[Mechanism of morphine-induced suppression of central nervous system blood flow].

Narcotic agonists such as morphine are well known to decrease cerebral blood flow and metabolism. To investigate a possible mechanism for this action of narcotics, cerebral blood flow (CBF) and spinal cord blood flow (SCBF) were simultaneously measured by the hydrogen clearance technique following intravenous or subarachnoid administration of morphine and subsequent naloxone in lightly anesthetized dogs. The effects of new opiate agonist + antagonists, cyclazocine and buprenorphine, alone or in a combination with naloxone on those CNS blood flow were also investigated. Morphine, 1 mg/kg iv, produced significant decreases in both CBF and SCBF (p less than 0.01), which were reversed by naloxone, 40 micrograms/kg. Naloxone per se did not produce any change in both. Cyclazocine, 50 micrograms/kg iv, also produced significant decreases in both CBF and SCBF (p less than 0.05), but the decreased CBF was not reversed by naloxone. Buprenorphine, 30 micrograms/kg, showed variable changes in both CBF and SCBF, resulted insignificant reduction. However, spinal subarachnoid administration of morphine, 0.2 mg, with which profound analgesia can be obtained in human adults, did not cause any changes in SCBF as well as CBF. These results suggest that narcotic analgesics affect SCBF similar to CBF and morphine decreases CNS blood flow via the activation of supraspinal opiate receptors.

Animals↗
PubMed1983

Plasma concentrations of lidocaine associated with cervical, thoracic, and lumbar epidural anesthesia.

We measured arterial plasma concentrations of lidocaine by enzyme immunoassay when 10 ml of 2% lidocaine without epinephrine was injected into the cervical, thoracic, or lumbar epidural spaces in 30 patients. There was no difference in the time courses of plasma levels of lidocaine. Peak concentrations were achieved 10 min after injection and were similar regardless of the site of injection. These results indicate the absence of significant differences in the rate of vascular absorption of lidocaine from different parts of the epidural space.

Adult↗
PubMed1983

Baroreflex control of heart rate during cardiac sympathectomy by epidural anesthesia in lightly anesthetized humans.

To evaluate the effects of acute sympathetic denervation on the baroreflex control of heart rate, baroreflex sensitivities were compared in lightly anesthetized humans who had either cervical (N = 20) or lumbar epidural anesthesia (N = 18), or neither (N = 18). Levels of anesthesia during cervical block using 10 ml of 2% mepivacaine without epinephrine were C3-T7 and T7-S1 during lumbar epidural block. Baroreflex sensitivity was assessed with a pressor test using phenylephrine infusion to increase systolic blood pressure by 60 mm Hg within 2 min. There were no statistically significant differences in the baroreflex sensitivities in the absence of epidural block and during lumbar epidural block, the slopes of the regression line (in msec of RR interval change per mm Hg increase in systolic blood pressure, i.e., msec/mm Hg) relating systolic pressure and the succeeding pulse interval being 3.8 +/- 1.4 (mean +/- SD) and 3.7 +/- 1.7, respectively. The mean slope during cervical block, 1.1 +/- 1.2 msec/mm Hg, was significantly different from the slopes observed in the absence of epidural block and during lumbar epidural block (P less than 0.01). The results suggest that cardiac sympathectomy induced by epidural anesthesia can suppress partially baroreceptor function by interrupting sympathetic efferent fibers innervating the heart during high levels of epidural anesthesia, but that lumbar sympathectomy during epidural anesthesia is unlikely to affect baroreceptor activity.

Adult↗
PubMed1983

Effects of intravenous or subarachnoid morphine on cerebral and spinal cord hemodynamics and antagonism with naloxone in dogs.

In order to elucidate the possible mechanism(s) by which opiates may affect cerebral and spinal circulation, and cerebral metabolism, cerebral blood flow (CBF) and spinal cord blood flow (SCBF) were measured simultaneously following intravenous or subarachnoid administration of morphine in dogs lightly anesthetized with halothane. The mean values of CBF and SCBF, using hydrogen clearance methods, were 52.3 +/- 14.7 ml . 100 g-1 . min-1 (mean +/- 1 SD) and 22.3 +/- 9.0 ml . 100 g-1 . min-1, respectively. Morphine hydrochloride, 1 mg/kg, when given intravenously, reduced both CBF and SCBF to approximately 73% of the control values (P less than 0.01). These changes were accompanied by decreases in the cerebral metabolic rates for oxygen (CMRO2) and glucose (CMRglucose). The circulatory effects and, in part, the metabolic effects, were reversed by naloxone 40 microgram/kg iv. Prior administration of naloxone blocked the morphine effects on CBF and SCBF and suppressed the effects on CMRO2 and CMRglucose. The decreases in blood pressure (MAP) and heart rate (HR) were similar following morphine iv with or without prior administration of naloxone. However, when 0.2 mg morphine was injected into the spinal subarachnoid space, the above variables remained unaffected. Neither naloxone alone, nor its subsequent intravenous administration following spinal morphine, affected cerebral and spinal circulatory or cerebral metabolic indices. These results indicate that intravenous morphine affects both cerebral and spinal cord blood flow via the opiate receptors at supraspinal sites of action.

Animals↗
PubMed1982

Circulatory responses to airway stimulation and cervical epidural blockade.

In order to investigate the effects of acute cardiac sympathectomy, the circulatory responses due to tracheal intubation and broncho-carinal stimulation were compared in lightly anesthetized, paralyzed patients who had either cervical (n = 18) or lumbar epidural blockade (n = 18), or neither (n = 12). The mean analgesic levels obtained using 2% mepivacaine with epinephrine were C4-T8 in the cervical group, and T7-S1 in the lumbar group. Increases in arterial blood pressure (AP) and heart rate (HR) due to laryngoscopy were significant (P less than 0.01) but similar in the three groups of patients. Broncho-carinal stimulation by a suction catheter did not produce noticeable changes in AP and HR in the cervical group; significant increases were observed in the other two groups (P less than 0.01). It was concluded from this study that acute sympathectomy induced in part by cervical or lumbar epidural block does not attentuate circulatory responses due to laryngoscopy and tracheal intubation. The cervical blockade, however, can prevent such responses due to broncho-carinal stimulation without predominant vagotonic reflexes; this may be attributed to the interruption of sympathetic afferents to the spinal cord at the epidural level.

Adult↗