[Dose-response study of preincisional buprenorphine on emergence time and postoperative analgesic requirement in patients anesthetized with sevoflurane].

The effect of intravenous buprenorphine on emergence time from sevoflurane anesthesia and postoperative analgesic requirement was evaluated after otolaryngeal surgeries. Forty-five patients were randomly assigned to one of three treatment groups (n = 15 each): Control-group received saline as a control; 2 micrograms-group received buprenorphine 2 micrograms.kg-1; and 4 micrograms-group received buprenorphine 4 micrograms.kg-1, respectively. Study drug was administered intravenously at the induction of general anesthesia. Anesthesia was maintained with sevoflurane (1.5%) and nitrous oxide (66%) in oxygen. The pain score, postoperative analgesic requirement, and incidence of nausea and/or vomiting were examined. The emergence times were 16.4 +/- 3.5, 14.7 +/- 5.2, and 17.8 +/- 7.7 min [mean +/- SD], in the control-group, the 2 micrograms-group, and the 4 micrograms-group, respectively. There were no differences among the groups in term of the end-tidal sevoflurane concentration immediately before tracheal extubation. In the control-group, the 2 micrograms-group, and the 4 micrograms-group, 10, 1, and 3 patients, requested additional analgesics during the first 24 hours after surgery, respectively (control-group vs. 2 micrograms-group and 4 micrograms-group, P < 0.05). Nausea and vomiting occurred more frequently in the 2 micrograms-group and the 4 micrograms-group. We conclude that buprenorphine (2 or 4 micrograms.kg-1) reduced analgesic requirement during the first 24 hours after surgery without delaying emergence from sevoflurane anesthesia.

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.

A case of progressive congestive heart failure secondary to severe anemia in a patient presenting with uterine hemorrhage.

In this report, we present a 42-year-old female patient who was transferred to our emergency department due to symptoms of congestive heart failure. She presented with severe anemia (hemoglobin was 1.3 g dl(-1), and hematocrit was 6.0%) due to continuous uterine hemorrhage and metabolic acidosis, otherwise she seemed to be free from illness. We diagnosed that she was suffered from chronic severe anemia due to uterine hemorrhage and congestive heart failure. Monitoring her hemodynamic status, treatment of congestive heart failure using diuretics and inotropes in combination with blood transfusion brought her good recovery. We discussed this case from the mechanisms of development of congestive heart failure in a chronic severe anemic condition, and pointed out that distributive effects of sodium and water may develop congestive heart failure without myocardial dysfunction in such a condition.

[A case of the CHARGE association with failed tracheal intubation].

We experienced a patient with the CHARGE association whose trachea could not be intubated in spite of attempts of laryngoscopy by four experienced anesthesiologists. Laryngeal fiberscope and neck X-ray examination carried out after the surgery, revealed the obvious enlargement of adenoid and tonsils, pressing the epiglottis to the posterior wall of the larynx. Although it is unknown whether enlargement of adenoid and tonsils are specific to the CHARGE association or not, patients with the CHARGE association are considered to have difficult airway. Preanesthetic evaluation of airway is indispensable for anesthesia in the patients with the CHARGE association.

[Anesthetic management of parturients with intracranial hemorrhage accompanied by seizure].

Two preeclamptic parturients, who presented with generalized seizure, underwent emergency cesarean section without confirmed diagnosis. They developed focal neurological signs postoperatively, and were subsequently diagnosed as subarachnoid hemorrhage due to rupture of an intracranial aneurysm and possibly of arteriovenous malformation. Diagnosis should be made at the earliest possible time for the optimal anesthetic as well as postoperative management of the mother.

Enhanced pain management for postgastrectomy patients with combined epidural morphine and fentanyl.

PURPOSE: To determine whether clinical advantages could be demonstrated by epidural fentanyl given in addition to epidural morphine for postgastrectomy analgesia. METHODS: One-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 + 100 micrograms fentanyl, 4 mg morphine alone, and 4 mg morphine + 100 micrograms fentanyl. Morphine and fentanyl were given epidurally approximately 60 and 15 min, respectively, before the completion of surgery. RESULTS: Addition 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 micrograms 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. CONCLUSION: The addition of 100 micrograms fentanyl to 2 mg or 4 mg epidural morphine provides clinical advantages over morphine alone for post-gastrectomy analgesia.

Oral clonidine premedication does not alter the efficacy of epidural test doses in adult patients anesthetized with isoflurane.

Clonidine premedication has been increasingly used in clinical anesthesia. Though clonidine was found to alter pressor responses to various sympathomimetics, its effect on epidural test dose efficacy to detect intravascular injection has never been evaluated. Eighty healthy patients were randomly assigned to one of four groups, each of which was anesthetized with 1% end-tidal isoflurane and 67% nitrous oxide in oxygen after endotracheal intubation. The control-epinephrine group (n=20) given no clonidine premedication received 3 ml of 1.5% lidocain with 15 µg epinephrine (1:200000) intravenously to simulate an intravenously administered epidural test dose. The control-saline group (n=20) given no clonidine premedication received 3 ml of normal saline intravenously. The clonidine-epinephrine and clonidine-saline groups (n=20 each) were identical to the control groups, but were premedicated with oral clonidine, approximately 5 µg·kg(-1), 90 min before induction of general anesthesia. Heart rate (HR) and systolic blood pressure (SBP) were measured by a blinded observer at 20-s intervals for 4 min after intravenous injections of the test dose or saline. Following intravenous test dose injection, there were no significant diferences between the control-epinephrine and the clonidine-epinephrine groups in mean maximum increments of both HR (28±3vs 30±3 bpm, [mean±standard error], respectively) and SBP (46±6vs 45±4 mmHg, respectively). Six patients in the control-epinephrine and 4 in the clonidine-epinephrine group developed negative HR responses (HR increment <20 bpm). Since HR and SBP were essentially unchanged in the two groups receiving saline, sensitivities (negative predictive values) based on the HR criterion (positive if ≥20 bpm increase in HR) were 80% and 70% (83% and 77%) with and without clonidine premedication, respectively (P>0.05 between groups). However, when a modified HR criterion (positive if ≥10 bpm increase in HR) was used, sensitivities, specificities, and positive and negative predictive values were all 100% with or without clonidine. On the other hand, all of 20 patients in the control-epinephrine and the clonidine-epinephrine groups exhibited positive SBP responses (SBP increment ≥15 mmHg). Therefore, based on the SBP criterion, sensitivities, specificities, and positive and negative predictive values were all found to be 100% regardless of the presence of clonidine. We conclude that oral clonidine 5µg·kg(-1) premedication alters neither (a) hemodynamic responses to the intravenously administered epidural test dose containing 15 µg epinephrine, nor (b) the efficacy for detecting intravascular injection based on either criterion in adult patients under stable isoflurane anesthesia.

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

1. A retrospective study of organophosphate (OP) poisoning in the intensive care unit was performed to analyze the incidence of respiratory failure. 2. The patients were treated initially with gastrointestinal 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.

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 micrograms epinephrine was an imperfect marker for intravascular injection during isoflurane anesthesia based on the conventional heart rate (HR) criterion (positive if > or = 20 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 micrograms 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 micrograms 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 = 20 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 = 15 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of an epidural test dose in adult patients anesthetized with isoflurane: lidocaine containing 15 micrograms 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.(ABSTRACT TRUNCATED AT 250 WORDS)

[Culture of the irrigating fluid of the epidural space obtained during chronic epidural catheterization].

The most serious complication during long-term epidural catheterization is epidural infection. Bacterial culture of the irrigating fluid of epidural space was carried out periodically in 39 patients in whom epidural catheters were inserted for a long period of time. Eight (17%) of 47 samples of epidural irrigating fluid were contaminated by the normal skin flora. All of these cases were accompanied with epidural contamination by the same organisms. No significant correlation was found between clinical signs of infection (low grade fever, leucocytosis and localized infective signs at the puncture site) and the contamination of the epidural irrigating fluid or that of the epidural catheter. When epidural irrigating fluid was contaminated, the epidural catheter was removed immediately and the patient was treated by antibiotics. None of the patients had epidural abscess or neurological deficit. In conclusion, bacterial culture of epidural irrigating fluid is valuable for the early diagnosis of epidural infection during long-term epidural catheterization.

[Effect of high dose-fentanyl on cerebrospinal fluid pressure in patients with normal intracranial pressure under halothane anesthesia].

The effect of high dose fentanyl on cerebrospinal fluid pressure (CSFP) was studied in 16 consented patients scheduled for major surgery with thoracotomy. In all patients, CSFP was measured through a 23G spinal needle at L3/L4 intervertebral space on the lateral position under light halothane-nitrous oxide-oxygen anesthesia (halothane 0.2-0.3%). After the control values were taken fentanyl, 50 micrograms.kg-1 (n = 8) or 100 micrograms.kg-1 (n = 8) was administered intravenously in 15 min. After the administration of both doses of fentanyl, CSFP decreased but not significantly. Mean blood pressure and cerebral perfusion pressure (CPP) decreased significantly within 5 min after the beginning of fentanyl administration but CPP did not decrease below 50 mmHg in any cases. These results indicate that high dose fentanyl has little influence on intracranial pressure in normal patients and could be used safely for neuroanesthesia.

[The relation between upper respiratory tract infection and mild hypoxemia during general anesthesia in children].

Anesthesiologists often face the problem of a child with symptoms of an acute upper respiratory infection (URI) presenting for surgery. Anesthesia in the presence of uncomplicated URI may not be contraindicated. However, we experienced three cases of such children in which lung atelectasis developed after the induction of general anesthesia. Because continuous monitoring of arterial oxygen saturation by pulse oximetry (SpO2) was useful for detecting mild hypoxemia in these patients, we retrospectively examined the possible association between URI symptoms and SpO2 in 63 children. Patients with symptoms of URI showed a significantly high incidence of decreased SpO2 to below 95% for 5 minutes. Our results suggest that, with URI symptoms even uncomplicated, symptomatic patients have increased risks for the development of mild hypoxemia during anesthesia.

Conjugated superoxide dismutase reduces extent of caudate injury after transient focal ischemia in cats.

We tested the efficacy of preischemic and postischemic systemic treatment with 30,000 units polyethylene glycol-conjugated superoxide dismutase in a reperfusion model of focal cerebral ischemia. Forty-one anesthetized cats underwent 2 hours' occlusion of the left middle cerebral artery and both common carotid arteries followed by 4 hours of reperfusion. Cats were blindly assigned to one of three groups: treatment with vehicle (10% polyethylene glycol in saline, n = 17), pretreatment with drug 3 hours before ischemia (n = 12), and posttreatment with drug at the time of reperfusion (n = 12). Size of the ischemic injury was calculated from 2,3,5-triphenyltetrazolium chloride staining. Injury in the caudate nucleus was significantly reduced with pretreatment (28 +/- 6% of ipsilateral caudate volume, mean +/- SEM) compared with the vehicle (56 +/- 8%). Posttreatment did not significantly ameliorate caudate injury (46 +/- 10%). Between the first and second hours of ischemia ipsilateral caudate blood flow determined using microspheres increased significantly from 11 +/- 4 to 16 +/- 5 ml/min/100 g with pretreatment, but blood flow remained constant throughout ischemia with vehicle (8 +/- 2 ml/min/100 g) and posttreatment (10 +/- 3 ml/min/100 g). The size of cortical injury (vehicle, 17 +/- 5%; pretreatment, 11 +/- 3%; posttreatment, 17 +/- 5% of hemispheric volume) did not differ significantly among groups. Somatosensory evoked potential recovery did not differ among groups. We conclude that pretreatment with conjugated superoxide dismutase can ameliorate the extent of injury in an end-artery region, such as the caudate nucleus, in a reperfusion model of focal ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Consistency of cerebral blood flow and evoked potential alterations with reversible focal ischemia in cats.

To enhance the consistency of the ischemic insult caused by reversible transorbital middle cerebral artery occlusion, we investigated the variability of somatosensory evoked potential amplitudes and regional cerebral blood flow in 26 anesthetized cats using four procedures to induce transient ischemia. These procedures included 60 minutes of left middle cerebral artery occlusion with or without left common carotid artery occlusion and 120 minutes of left middle cerebral artery occlusion with or without bilateral common carotid artery occlusion. Blood flow in the left middle cerebral artery territory was markedly and consistently reduced to less than 20 ml/min/100 g with simultaneous occlusion of the left middle cerebral artery and both common carotid arteries. The standard deviation of blood flow with this procedure (5.4) was less than that with the other three procedures (13-25). The amplitudes of ipsilateral somatosensory evoked potentials were decreased to approximately 20% of control during ischemia with all four procedures. During reperfusion, amplitudes recovered more slowly, to half of control, after both procedures involving 120 minutes of ischemia. After 120 minutes of reperfusion, the range of amplitudes was smallest in the group exposed to middle cerebral artery occlusion with bilateral common carotid artery occlusion. The degree of recovery of the somatosensory evoked potentials correlated with residual blood flow in both the ipsilateral middle cerebral artery territory and in the white matter during ischemia. We conclude that the most consistent model of focal ischemia and reperfusion in cats in which there is partial recovery of somatosensory evoked potentials is occlusion of one middle cerebral artery and both common carotid arteries for 120 minutes.

Interaction between intravenous lidocaine and epinephrine on hemodynamics and plasma potassium homeostasis in dogs anesthetized with halothane.

To delineate some clinical features of an accidental intravascular injection of local anesthetic solution containing epinephrine during the attempt of regional block, the interaction between intravenous lidocaine and epinephrine on hemodynamics and potassium homeostasis was investigated in halothane-anesthetized dogs using three types of combination of lidocaine and epinephrine. These included 1% plain lidocaine (10 mg/kg), 1% lidocaine-epinephrine solution (10 mg/kg-5 micrograms/kg) and epinephrine-normal saline solution (1:200,000, 5 micrograms/kg). Although lidocaine did not produce any changes in systemic or pulmonary hemodynamics, epinephrine and lidocaine-epinephrine solution produced transient multifocal premature ventricular contractions associated with huge hemodynamic changes. Lidocaine-epinephrine solution caused a 43% increase in mean arterial pressure, a 107% increase in mean pulmonary artery pressure and a 244% increase in pulmonary capillary wedge pressure (p less than 0.05). These changes did not differ from those observed following epinephrine. In contrast, stroke volume decreased significantly to 70% of control after lidocaine-epinephrine, while neither epinephrine nor lidocaine produced a significant change. Lidocaine did not affect plasma potassium concentration, whereas both epinephrine and lidocaine-epinephrine produced significant increase in plasma potassium concentration (K+; 2.0 +/- 0.7 mEq/l with epinephrine and 1.8 +/- 1.2 mEq/l with lidocaine-epinephrine), which subsequently decreased to below control.