Naoki Matsumiya

The Effects of Subarachnoid Lidocaine and Phenylephrine on Spinal Cord and Cerebral Blood Flow in Dogs

To investigate the central nervous system circulation during spinal anesthesia, local spinal cord blood flow (SCBF) and cerebral blood flow (CBF) were measured simultaneously by the hydrogen clearance technique following subarachnoid lidocaine, phenylephrine, or a combination of both. The mean control values of SCBF and CBF were 22.4 ± 7.9 ml.100 g−1·min−1 and 53.1 ± 12.0 ml·100 g−1·min−1, respectively, in dogs lightly anesthetized with halothane.The subarachnoid administration of lidocaine solutions (1, 2, 3, and 5%), 1 ml, failed to produce statistically significant changes in SCBF (P > 0.05). Whereas, when phenylephrine (0.1, 0.2, 0.3, and 0.5%), 1 ml, was injected into the spinal subarachnoid space, SCBF decreased significantly with concentrations greater than 0.2% (P < 0.05). When a mixture of lidocaine (24 mg) and phenylephrine (1 mg) was administered into the subarachnoid space, SCBF decreased significantly and returned to control within 60–90 min. CBF did not change significantly with any of the injections, remaining within less than ±12% of control. Dextrose solutions in water (5 and 7.5%), which were used for dilution of the drugs, did not affect either SCBF or CBF. These results indicate that local spinal cord blood flow can be affected significantly during spinal anesthesia when phenylephrine is added to the local anesthetic solution. However, the circulatory effects of drugs injected into the spinal subarachnoid space appear to be restricted to the local spinal cord per se and do not involve other parts of the CNS.

Cardiovascular collapse in an infant after caudal anesthesia with a lidocaine-epinephrine solution.

The use of epinephrine in local anesthetic solutions is commonly accepted as a standard clinical practice in regional anesthesia. It has been suggested that in using such solutions the epinephrine per se counteracts, at least in part, the cardiac depression associated with local anesthetic toxicity (1-3). It has thus been advocated that the addition of epinephrine to the local anesthetic solution should always be considered in order to avoid life-threatening cardiovascular complications (1-3). As far as we know, epinephrine per se has not been observed to produce a fatal adverse reaction during regional anesthesia (4). However, we experienced a case in which acute circulatory collapse developed after the injection of an epinephrine-lidocaine solution for caudal anesthesia in an infant.

Efficacy of Simulated Epidural Test Doses in Adult Patients Anesthetized with Isoflurane: A Dose-Response Study

A recent study demonstrated that an epidural test dose containing 15 micro gram epinephrine was an imperfect marker for intravascular injection during isoflurane anesthesia based on the conventional heart rate (HR) criterion (positive if >or=to20 bpm increase).We have determined the effects of epinephrine doses and isoflurane concentrations on these efficacies in healthy adult patients during isoflurane anesthesia. Eighty patients were randomly assigned to one of four groups according to the simulated test dose injected intravenously (IV) under 1% end-tidal isoflurane and nitrous oxide after endotracheal intubation. The saline group (n = 20) received 3 mL normal saline; the epinephrine 7.5 group (n = 20) received 3 mL 1.5% lidocaine containing 7.5 micro gram epinephrine; the epinephrine 15 and epinephrine 22.5 groups (n = 20 each) received an identical dose and volume of lidocaine but containing 15 and 22.5 micro gram epinephrine, respectively. HR and systolic blood pressure (SBP) were monitored invasively for 4 min after IV injection of the study drug. Although none in the saline group developed a HR increase >or=to20 bpm, 2, 14, and 12 patients elicited positive responses in the epinephrine 7.5, 15, and 22.5 groups (10%, 70%, and 60% sensitivities), respectively. If a positive HR response was defined by an increase of 10 bpm, sensitivities were 55%, 100%, and 100% in the epinephrine 7.5, 15, and 22.5 groups, respectively. On the other hand, none in the saline group, 12 in the epinephrine 7.5 group, and all patients in the epinephrine 15 and 22.5 groups developed maximum SBP increases >or=to15 mm Hg. An additional 40 patients were randomized to receive isoflurane 0.5% (isoflurane 0.5 group, n = 20) or 1.5% (isoflurane 1.5 group, n = 20), and hemodynamic changes were similarly studied after an IV test dose containing 15 micro gram epinephrine. Based on the HR criterion >or=to20 bpm increase, the isoflurane 0.5 and 1.5 groups produced 100% and 30% sensitivities, respectively. Sensitivity of the isoflurane 1.5 group was still 70% based on the modified criterion (>or=to10 bpm increase). All patients in both groups developed SBP increases >or=to15 mm Hg, giving 100% sensitivities under both isoflurane concentrations. We conclude that under stable isoflurane anesthesia (a) at least 15 micro gram epinephrine should be used as a test dose, (b) peak HR increase >or=to10 bpm should be regarded as a positive response under <or=to1% isoflurane, and (c) peak SBP criterion (positive if >or=to15 mm Hg increase) is applicable between 0.5% and 1.5% isoflurane. (Anesth Analg 1995;81:987-92)

Reexpansion pulmonary edema after mediastinal tumor removal

udden evacuation of pneumothorax or pulmonary effusion may cause edema of ipsilateral S lung (reexpansion pulmonary edema, RPE) (1). Other reports described a more acute form of RPE associated with lung reexpansion after several hours of atelectasis (2,3). Can lung reexpansion after onelung ventilation cause the edema formation of the nondependent lung? We describe a case of RPE that developed immediately after the removal of a mediastinal tumor during one-lung ventilation anesthesia in a young patient.

Efficacy of an Epidural Test Dose in Adult Patients Anesthetized with Isoflurane: Lidocaine Containing 15 micro gram Epinephrine Reliably Increases Arterial Blood Pressure, but Not Heart Rate

When continuous epidural anesthesia is combined with general anesthesia, the only objective sign of intravascular migration of the epidural catheter are the increments of heart rate (HR) or arterial blood pressure after a local anesthetic test dose containing epinephrine.However, the efficacy of a simulated intravenous (IV) test dose in adult patients under general anesthesia has not been determined. Thirty adult patients were randomly assigned to one of two groups, each of which was anesthetized with 1% end-tidal isoflurane and nitrous oxide after endotracheal intubation. The epinephrine group (n = 15) was given 3 mL of 1.5% lidocaine with epinephrine (1:200,000) IV to simulate an IV administered epidural test dose. The saline group (n = 15) was identical to epinephrine group, but received 3 mL of normal saline IV. HR and arterial blood pressure were measured at 20-s intervals for 4 min after IV injection. In the epinephrine group, significant increases in HR compared with the baseline value were observed from 40 to 80 s after the IV test dose with a mean maximum HR increase of 24 +/- 2 bpm (mean +/- SEM) occurring at 48 +/- 3 s. However, 5 of 15 patients in the epinephrine group developed HR increments smaller than 20 bpm (sensitivity 67%). Since HRs were essentially unchanged in the saline group, specificity, positive predictive value (+PV), and negative predictive value (-PV) were 100%, 100%, and 75%, respectively. On the other hand, all patients in the epinephrine group and none in the saline group exhibited systolic blood pressure (SBP) increases more than 15 mm Hg, giving sensitivity, specificity, +PV, and -PV all 100%. We conclude that (a) the low -PV based upon HR criterion does not provide support for the safety of the procedure, and (b) clinical judgment of suspected intravascular migration of the epidural catheter should be made, possibly using SBP criterion in adult patients under isoflurane anesthesia. (Anesth Analg 1995;80:310-4)

Elevated amylase is related to the development of respiratory failure in organophosphate poisoning

1 A retrospective study of organophosphate(OP) poison ing in the intensive care unit was performed to analyze the incidence of respiratory failure. 2 The patients were treated initially with gastrointest inal decontamination including gastric lavage and the administration of activated charcoal with cathartic. Further management included intravenous pralidoxim and atropine and ventilatory support. 3 Of the 32 OP poisoning patients, 16 patients developed respiratory failure and received ventilatory support. 4 An increase in plasma amylase above the normal range on the day of admission was related to the development of respiratory failure. 5 In OP poisoning, the elevation of amylase level was predictive of the subsequent respiratory failure.

End-tidal carbon dioxide monitoring during awake blind nasotracheal intubation

STUDY OBJECTIVE To test the usefulness of the end-tidal carbon dioxide monitor in facilitating awake blind nasotracheal intubation in patients with potentially difficult airways. DESIGN Randomized, controlled comparison of regimen. SETTING Inpatient surgery clinic at a university hospital. PATIENTS Sixty-one consecutive patients with potentially difficult airways. INTERVENTIONS After airway anesthesia with 4% lidocaine was administered to all patients, either fentanyl and diazepam (n = 30) or fentanyl alone (n = 31) was given intravenously before the awake blind nasotracheal intubation procedure. MEASUREMENTS AND MAIN RESULTS End-tidal carbon dioxide concentration, arterial blood pressure, heart rate, and arterial oxygen saturation (by pulse oximeter) were measured in each patient during the awake blind nasotracheal intubation procedure. The day after anesthesia and surgery, each patient was asked to assess the degree of discomfort experienced during the procedure. In 54 of 61 patients, the end-tidal carbon dioxide monitor facilitated awake blind nasotracheal intubation. End-tidal carbon dioxide was significantly higher in patients given both fentanyl and diazepam than in those given fentanyl alone (7.4% +/- 1.4% vs 5.9% +/- 0.9%, respectively; p less than 0.05), but no patient in either group recalled the awake intubation as extremely uncomfortable. CONCLUSIONS Monitoring of end-tidal carbon dioxide is useful and valuable in both facilitating blind nasotracheal intubation and avoiding profound hypoventilation.

A case of transient diabetes insipidus associated with poisoning by a herbicide containing glufosinate.

Background: The herbicide BASTA® (AgrEvo, Germany), containing glufosinate ammonium (20%) and an anionic surfactant, polyoxyethylene alkylether sulfate (33%), is widely used. In acute oral BASTA poisoning, patients develop a variety of clinical signs, including disturbed consciousness, convulsions, and apnea. These effects are suspected to be due to the effects of glufosinate on the central nervous system. Case Report: A 60-year-old man ingested 500 mL of BASTA herbicide in a suicide attempt. He developed not only unconsciousness, respiratory distress, and convulsions but also an increase in urine output (7885 mL/d), elevated serum sodium (167 mEq/L), elevated plasma osmolality (332 mOsm/kg), and a decrease in both urine osmolality (200 mOsm/kg) and urine specific gravity (1.003), which suggested the development of diabetes insipidus. The plasma level of antidiuretic hormone remained within the normal range (1.3 pg/mL), despite high plasma osmolality. The administration of desmopressin was successful in normalizing urine volume, specific gravity, and osmolality. Serum sodium corrected gradually within 48 hours. The possible mechanisms causing the diabetes insipidus are discussed.

Enhanced pain management for post- gastrectomy patients with combined epidural morphine and fentanyl

PurposeTo determine whether clinical advantages could be demonstrated by epidural fentanyl given in addition to epidural morphine for postgastrectomy analgesia.MethodsOne-hundred and twenty two patients undergoing elective gastrectomy were prospectively studied in a randomised, double-blind fashion. All patients received epidural lidocaine 1.5% with epinephrine (1:200,000) followed by light general anaesthesia for surgical anaesthesia. They were assigned to four groups according to the combinations of each epidural opioid: 2 mg morphine alone, 2 mg morphine + 100μg fentanyl, 4 mg morphine alone, and 4 mg morphine + 100 μg fentanyl. Morphine and fentanyl were given epidurally approximately 60 and 15 min, respectively, before the completion of surgery.ResultsAddition of epidural fentanyl to both doses of morphine not only decreased intensity of pain associated with coughing during the early postoperative period, but also prolonged the time until the first analgesic request at each morphine dose studied. Of the combination doses, 4 mg morphine + 100 μg fentanyl provided the longest time to the first request for analgesic, and was associated with least amount of postoperative analgesic supplement and best patient satisfaction without increasing incidence of side effects.ConclusionThe addition of 100 μg fentanyl to 2 mg or 4 mg epidural morphine provides clinical advantages over morphine alone for post-gastrectomy analgesia.RésuméObjectifDéterminer s’il est cliniquement avantageux d’ajouter du fentanyl à la morphine épidurale pour procurer l’analgésie après une gastrectomie.MethodesCent vingt-deux patients programmés pour une gastrectomie non urgente ont participé à cette étude aléatoire en double aveugle. Pour l’intervention, tous les patients ont reçu une épidurale à la lidocaïne 1,5% adrénalinée (1:200,000) suivie d’une anesthésie générale légère. Les patients étaient répartis en quatre groupes déterminés par le mode d’administration des morphiniques: morphine seule 2 mg, morphine 2 mg + fentanyl 100 μg, morphine 4 mg seule, et morphine 4 mg + fentanyl 100 μg. La morphine et le fentanyl ont été administrés par la voie épidurale environ 60 et 15 min avant la complétion de la chirurgie.RésultatsNon seulement l’ajout de fentanyl épidural aux deux doses de morphine diminuait l’intensité de la douleur associée à la toux de la période postopératoire immédiate mais prolongeait de plus l’intervalle précédant la première demande d’analgésique avec chacune des doses de morphine. Cette prolongation était la plus marquée avec morphine 4 mg + fentanyl 100 μg. Cette dernière combinaison est celle qui nécessitait le moins de supplément analgésique et procura’rt le plus haut degré de satisfaction chez le patient sans augmenter les effets secondaires.ConclusionIl est cliniquement avantageux d’ajouter du fentanyl à la morphine épidurale pour l’analgésie après une gastrectomie.

Primary and Secondary Spontaneous Pneumothorax: Prevalence, Clinical Features, and In-Hospital Mortality

Background. Optimal treatment practices and factors associated with in-hospital mortality in spontaneous pneumothorax (SP) are not fully understood. We evaluated prevalence, clinical characteristics, and in-hospital mortality among Japanese patients with primary or secondary SP (PSP/SSP). Methods. We retrospectively reviewed and stratified 938 instances of pneumothorax in 751 consecutive patients diagnosed with SP into the PSP and SSP groups. Factors associated with in-hospital mortality in SSP were identified by multiple logistic regression analysis. Results. In the SSP group (n = 327; 34.9%), patient age, requirement for emergency transport, and length of stay were greater (all, p < 0.001), while the prevalence of smoking (p = 0.023) and number of surgical interventions (p < 0.001) were lower compared to those in the PSP group (n = 611; 65.1%). Among the 16 in-hospital deceased patients, 12 (75.0%) received emergency transportation and 10 (62.5%) exhibited performance status (PS) of 3-4. In the SSP group, emergency transportation was an independent factor for in-hospital mortality (odds ratio 16.37; 95% confidence interval, 4.85–55.20; p < 0.001). Conclusions. The prevalence and clinical characteristics of PSP and SSP differ considerably. Patients with SSP receiving emergency transportation should receive careful attention.