Although an epiglottic cyst is often asymptomatic and harmless to the patient, discovery of a large epiglottic cyst after induction of anesthesia is a potentially life-threatening problem for the patient and provides a challenge for the anesthesiologist in airway management. We experienced a case of unanticipated difficult mask ventilation and intubation as a result of an asymptomatic epiglottic cyst. A 37-year-old woman presented for elective removal of a brain tumor. She had normal mouth opening and neck extension; no masses or distortions of the tongue or neck were observed. She was premedicated with 0.2 mg glycopyrrolate intramuscularly. Anesthesia and paralysis were induced with 250 mg thiopental, fentanyl 100ng and pipecuronium 6 mg. It was noted that ventilation of the lungs via mask was difficult. Despite insertion of an oropharyngeal airway, ventilation proved to be more difficult. Intubation was attempted. Direct laryngoscopy revealed a 2 cm cyst arising from the epiglottis. The cyst completely obscured the view of the epiglottis and larynx, preventing intubation despite multiple attempts by three anesthesiologists. We consulted an otolaryngologist and awakened the patient. During further questioning in the post anesthesia care unit she admitted to a several-years of dysphagia. Next day, she was admitted to the operation room for removal of an epiglottic cyst. She was intubated using fiberoptic bronchoscope guided awake intubation, and the remainder of anesthetia and the operation proceeded uneventfully. The pathology report confirmed the finding of a 2.5 X 1.5 X 1.5 cm epidermal cyst.
Adult ; Airway Management ; Anesthesia ; Brain Neoplasms ; Bronchoscopes ; Deglutition Disorders ; Epidermal Cyst ; Epiglottis ; Female ; Fentanyl ; Glycopyrrolate ; Humans ; Intubation* ; Laryngoscopy ; Larynx ; Lung ; Masks ; Mouth ; Neck ; Paralysis ; Pathology ; Pipecuronium ; Thiopental ; Tongue ; Ventilation

BACKGROUND: Isoflurane and enflurane have different activity on the cytoplasmic calcium movements of a cardiac muscle cell and a vascular smooth muscle cell. Isoflurane is less depressive in cardiac contraction, and more potent in vasodilation than enflurane. This study is to elucidate the effects of these anesthetics on the ST-segment displacement. METHODS: The anesthesia was induced by the intravenous injection of thiopental (6 mg.kg 1) and pipecuronium (0.1 mg.kg 1). The patients (n=80) undergoing tympanoplasty were randomly allocated to two groups for the maintenance METHODS: Group I was inhaled with isoflurane (1~2%), O2 (2 L.min 1), and N2O (2 L.min 1), Group II, enflurane (1.5~2.5%), O2 and N2O. Continuous electrocardiographic recordings with Holter monitor were made during anesthesia. The recordings were scanned on an Avionics Electrocardioscanner with particular emphasis on ST-segment changes. The criteria describe an episode as ST-segment displacement greater than or equal to 0.1 mV measured 80 ms from J-point lasting for more than 1 minutes. Mean heart rate was calculated. Results were categorized as induction, maintenance, and emergence, and inferred from unpaired t-test, x2-test, and Mann-Whitney U test with p<0.05 considered significant. RESULTS: Enflurane had higher incidence of ST-segment depression during induction, more maximally depressed ST-segment during maintenance and slower heart rate during induction and maintenance than isoflurane. CONCLUSION: It could be suggested that enflurane make stronger influence on the ST-segment depression than isoflurane. However, the clinical significance remains to be studied.
Anesthesia* ; Anesthetics ; Calcium ; Cytoplasm ; Depression ; Electrocardiography ; Enflurane* ; Heart Rate ; Humans ; Incidence ; Injections, Intravenous ; Isoflurane* ; Muscle, Smooth, Vascular ; Myocytes, Cardiac ; Pipecuronium ; Thiopental ; Tympanoplasty ; Vasodilation

BACKGROUND: Studies in animals suggest that pipecuronium dose not induce hemodynamic chan-ges related to histamine release or to an effect on the autonomic nervous system. Therefore the effects of bolus administration of large doses of pipecuronium, up to 0.20 mg/kg, on the intubation condition, onset and duration of neuromuscular blockade, heart rate and blood pressure were studied during fentanyl- nitrous oxide anesthesia. METHOD: Forty adults were randomly assigned to receive a bolus injection of either 0.05, 0.10, 0.15, 0.20 mg/kg of pipecuronium. Neuromuscular blockade was measured using mechanomyographic activity of the adductor pollicis muscle after supramaximal stimulation of the ulnar nerve. Four subgroups of 10 patients received pipecuronium doses of 0.05, 0.10, 0.15 and 0.20 mg/kg, respectively, as an intubating dose. RESULTS: The times of onset and clinical duration (mean sem) after each dose were as follows: 0.05 mg/kg, 2.98 0.42 and 41.5 2.42 min; 0.10 mg/kg, 1.54 0.06 and 82.9 7.48 min; 0.15 mg/kg, 1.41 0.14 and 124.8 13.1 min; 0.20 mg/kg, 1.12 0.05 and 187.1 12.8 min. The intubation condition, time of onset and duration after doses of 0.05 mg/kg were significantly different from values after the higer doses. The duration was increased with dose-increments. No dose-related changes in heart rate or blood pressure were observed. CONCLUSION: The authors conclude that dose of 0.10 mg/kg and over has good intubation condition clinically and large bolus dose of pipecuronium can be safely used with a significantly prolonged duration of action without hemodynamic change.
Adult* ; Anesthesia ; Animals ; Autonomic Nervous System ; Blood Pressure ; Heart Rate ; Hemodynamics ; Histamine Release ; Humans ; Intubation ; Intubation, Intratracheal* ; Neuromuscular Blockade ; Nitrous Oxide ; Pipecuronium* ; Ulnar Nerve

BACKGROUND: High dose fentanyl for cardiac surgery in neonates, infants and children can cause severe bradycardia and chest wall rigidity that result in decreased cardiac output and oxygen desaturation due to fixed stroke volume in pediatric patients. To ameliorate the effects of fentanyl, it is common to administer neuromuscular blocking drugs with wanted cardiovascular side effects. This study was designed to compare the cardiovascular variables and oxygen saturation among different muscular relaxants in high dose fentanyl anesthesia. METHODS: Thirty pediatric cardiac patients were allocated randomly into three muscle relaxant groups treated with 0.2 mg/kg pancuronium (n=10), 0.2 mg/kg vecuronium (n=10) or 0.2 mg/kg pipecuronium (n=10) after receiving an initial bolus dose of 25 g/kg of fentanyl. Changes of heart rate (HR), mean arterial blood pressure (MAP), rate-pressure-product (RPP) and oxygen saturation (SpO2) were observed. The same cardiovascular variables were also observed 1 and 2 minutes after the second bolus dose of 25 g/kg fentanyl and compared to the results among muscle relaxants. RESULTS: HR, MAP and RPP decreased significantly (p<0.05) 1 and 2 minutes after injection of the 1st fentanyl, which returned to levels above the control value after administration of pancuronium, vecuronium or pipecuronium. Among muscle relaxants, pancuronium caused the most rapid and significantly high level compared to the control value in HR and MAP. Next was pipecuronium and then vecuronium. In clinical setting, SpO2 was decreased after the 1st fentanyl injection and increased after the injection of muscle relaxants, but not significant statistically. CONCLUSION: In view of hemodynamic changes, pancuronium is most efficient and rapid in returning the hemodynamic variables that was decreased after high dose fentanyl anesthesia in neonates, infants and children whose cardiac output was dependent on HR due to relatively fixed stroke volume.
Anesthesia* ; Arterial Pressure ; Bradycardia ; Cardiac Output ; Child* ; Fentanyl* ; Heart Rate ; Hemodynamics ; Humans ; Infant* ; Infant, Newborn* ; Neuromuscular Blockade ; Oxygen ; Pancuronium* ; Pipecuronium* ; Stroke Volume ; Thoracic Surgery ; Thoracic Wall ; Vecuronium Bromide*

BACKGROUND: Long-term phenytoin therapy induces resistance to the neuromuscular blocking effects of metocurine, atracurium, doxacurium, and pipecuronium. This study examine neuromuscu-lar blocking effect and recovery of mivacurium in isolated rat phrenic-hemidiaphragm with two-weeks phenytoin pretreatment. METHOD: After the administration of 14 days of phenytoin 40 mg/kg, administered intraperitoneally twice daily (n=10), ED90, antagonism of neostigmine and 4-aminopyridine on the electrically evoked twitch response and train-of-four (TOF) stimulation were compared to control groups in isolated rat phrenic-hemidiaphragm preparation. RESULTS: ED90 was significantly greater in the phenytoin group than in the control group (319 +/- 39.5 g vs. 209.5 +/- 52.2 g, respectively). After the administration of neostigmine 0.75 M, the recovery of the single twitch and TOF ratio were significantly lesser in the phenytoin group than in the control group (single twitch; 19.6 +/- 6.6% vs. 69.2 +/- 9.4%, TOF ratio; 0.258 +/- 0.149 vs. 0.543 +/- 0.1, respectively). After the administration of 4-aminopyridine 40uM, the recovery of the single twitch and TOF ratio were no significant differrence between the phenytoin group and the control group (twitch; 118.1 +/- 25.3% vs. 122.6 +/- 24.8%, TOF ratio; 0.937 +/- 0.051 vs. 0.949 +/- 0.067, respectively). CONCLUSION: Long-term phenytoin therapy induces resistance to the neuromuscular blocking effects of mivacurium.
4-Aminopyridine ; Animals ; Atracurium ; Drug Interactions ; Neostigmine ; Neuromuscular Blockade* ; Phenytoin* ; Pipecuronium ; Rats*

BACKGROUND: It has been shown that L-type calcium channel blockers increase the muscle relaxation effects of non-depolarizing neuromuscular blocking agents whereas the potentiated neuromuscular blocking effects by L-type calcium channel blocker are resistant to reversal by neostigmine. The aims of this study were 1) to see whether the pretreatment of L-type calcium channel blocker, such as verapamil, aggravates the pipecuronium-induced muscle relaxation, 2) if so, to see whether these effects are reversed by anticholinesterase, such as neostigmine and edrophonium or potassium channel blocker, such as 4-aminopyridine. METHODS: The rat-phrenic nerve-hemidiaphragms (n=60) were prepared. Twenty microgram of pipecuronium was administered to all organ bath. All samples were divided into two groups according to the administration of 10uM of verapamil i.e. verapamil pretreated, non-pretreated group. The amounts of administered pipecuronium were gradually increased by 4ug until the force of twitch decreased to 10% of control value in both groups. Each group was subdivided into three groups according to the administration of 0.75 M of neostigmine, 12.4 uM of edrophonium or 40uM of 4-aminopyridine. RESULTS: The dose of pipecuronium required for the decrease of contractile force to 10% of control value was less in verapamil pretreated group than in non-pretreated group. And, the decrease of contractile force in both groups was more effectively reversed by 4-aminopyridine than neostigmine and edrophonium. CONCLUSIONS: Verapamil potentiates the pipecuronium-induced neuromuscular blockade and 4-aminopyridine is more effective to reverse verapamil pretreated, pipecuronium induced neuromuscular blockade.
4-Aminopyridine* ; Baths ; Calcium Channels, L-Type ; Edrophonium* ; Muscle Relaxation ; Neostigmine* ; Neuromuscular Blockade* ; Neuromuscular Blocking Agents ; Pipecuronium* ; Potassium Channels ; Verapamil*

BACKGROUND: Pipecuronium bromide is a long-acting steroidal neuromuscular blocking drug. This study was designed to evaluate the neuromuscular-blocking action and the cardiovascular effects of pipecuronium in patients under O2-N2 O-enflurane anesthesia, by comparing with those of pancuronium and vecuronium. METHODS: Fifty-one adult patients (ASA class 1 or 2) were randomly received pipecuronium 0.1 mg/kg (n=17), pancuronium 0.12 mg/kg (n=17), or vecuronium 0.1 mg/kg (n=l7) as a single intravenous bolus dose. Anesthesia was induced with thiopental 5 mg/kg, followed by one of the muscle relaxants. Patients were then given O2 (2 L/min) - N2O(2 L/min)-enflurane(1.8 vol%) by face mask. Trachea was intubated, and anesthesia was maintained with O2 (2 L/min)- N2O(2 L/min)-enflurane(1-2.5 vol%) during whole study period. Neuromuscular blocking effect was assessed by response of the adductor pollicis muscle in 2Hz train-of-four(TOF) stimulation of ulnar nerve every 20 seconds. The times from administration of initial dose to loss and reappearance of four twitches to TOF were measured. Systolic and diastolic blood pressure(SAP,DAP) and heart rate(HR) were noninvasively measured. RESULTS: The onset times of pipecuronium, pancuronium, and vecuronium were 278+/-99, 268+/-67, and 208+/-56 seconds, respectively. The duration of action of pipecuronium, pancuronium, and vecuronium were 148+/-99, 145+/-35, and 52+/-12 minutes, respectively. SAP and DAP with pancuronium were significantly greater than those with pipecuronium or vecuronium I minute after the administration. No significant difference in SAP and DAP was found until 5 minutes after the administration among the agents. HR was increased significantly until 20 minutes after the administration of pancuronium. CONCLUSION: Pipecuronium is a long-acting drug suitable for longer operations in which cardiovascular stability is required.
Adult ; Anesthesia ; Blood Pressure ; Heart ; Humans ; Masks ; Neuromuscular Blockade* ; Pancuronium* ; Pipecuronium* ; Thiopental ; Trachea ; Ulnar Nerve ; Vecuronium Bromide*

BACKGROUND: Magnesium sulfate (MgSO4) is widely utilized in the treatment of preeclamptic hyperreflexia. It is well known that magnesium enhances nondepolarizing neuromuscular blockade. Eclamptic convulsions are almost always prevented by magnesium in plasma concentrations of 4 to 7 mEq/L. METHODS: The effects of various concentration of magnesium on the potency and reversibility of pipecuronium were investigated in vitro rat phrenic nerve-hemidiaphragm. The phrenic nerve-hemidiaphragm was dissected and suspended in organ bath containing modified Krebs' solution. Forty samples were divided into 4 groups (n=10 in each group). Group I was studied at the physiologic magnesium concentration(2.4 mEq/L, control group). Group II, III, IV were studied at the concentration of 4, 5.5, and 7 mEq/L, respectively. In each group, we added pipecuronium until twitch height decreased more than 90% of initial level. To compare the recovery, we added neostigmine and calcium, and then, measured TOF ratio. RESULTS: The amounts of added pipecuronium were 73.8+/-15.2 microgram (mean+/-S.D.) in Group I, 38.1+/-5.0 microgram in Group II, 33.0+/-4.1 microgram in Group III and 16.1+/-1.7 microgram in Group IV. The amounts of pipecuronium in Group II, III, IV were significantly less than Group I. After the addition of neostigmine, the values of TOF ratio were under 0.6 in all groups. But after the addition of calcium, all groups were recovered with TOF ratio over 0.85 except Group I. CONCLUSIONS: This study indicated that the increased magnesium concentration potentiated pipecuronium-induced neuromuscular blockade and at higher level, it was more apparent. Neostigmine was not significantly effective to reverse the pipecuronium-induced neuromuscular blockade potentiated with magnesium. But calcium was significantly effective.
Animals ; Baths ; Calcium ; Magnesium Sulfate ; Magnesium* ; Neostigmine ; Neuromuscular Blockade* ; Pipecuronium ; Plasma ; Rats* ; Reflex, Abnormal ; Seizures

The effects and interactions of metabolic and respiratory acid-base changes on electrically-evoked twitch response, train-of-four and tetanic stimulation with pipecuronium (Pip), vecuronium (Vec) and atracurium (Tra) were studied in the isolated rat hemi-diaphragm preparation. pip (3X10(-7) - 4X10(-6) M), Vec (3X10(-6) - 15X10(-6) M) and Tra (10(-6) - 3X10(-5) M) decreased the electrically-evoked (phrenic nerve stimulation, 0.1 Hz, 0.2 ms, 10 V) twitch response in a dose related fashion and Pip was more potent than Vec and Tra. In the alkali state (pH 7.6 or high HCO3 ), the decrements of twitch response, train-of-four and tetanus ratio induced by Pip (1.5uM) were potentiated, but the effects of Vec or Tra were markedly intensified by acid midium (pH 7.2 or low HCO3 ). And also, decreasing pH by increasing PCO2 or by decreasing HCO3 intensified the effects of Vec and Tra, whereas it reversed by Pip. Conversely, increasing pH by decreasing PCO2 or by increasing HCO3 antagonized the effects of Vec and Tra, whereas it potentiated the Pip effect. On the basis of these finding, the result of the present study suggest that neither PCO2 nor HCO3 has a specific action, but that changes in pH may be responsible for the results. In addition, the differences of the above results by each drugs may not be due to the number of quaternary ammonium of the agents. And also, indicate that the effective site of the influence of the acid-base change upon the neuromuscular blocking effects might be prejunctional nerve terminal.
Alkalies ; Ammonium Compounds ; Animals ; Atracurium ; Hydrogen-Ion Concentration ; Neuromuscular Blockade ; Pipecuronium ; Rats* ; Tetanus ; Vecuronium Bromide

There is an evidence that onset time and potency of the non-depolarizing neuromuscular blocking agents are related. However the relationship between onset time and the recovery has not been investigated yet. In this experiment, the onset times of six neuromuscular blocking agents have been compared with their recovery times. The neuromuscular transmission of mivacurium 0.15 mg/kg, atracurium 0.4 mg/kg, vecuronium 0.08 mg/kg, pipecuronium 0.08 mg/kg, pancuronium 0.1 mg/kg and succinylcholine 1 mg/kg were studied in 58 adult healthy patient (ASA I and II) during O2-N2O-isoflurane anesthesia using train-of-four stimulation with Relaxograph. It has been demonstrated that there is a close relationship between onset time and recovery in depolarizing neuromuscular blocking agent but not in non-depolarizing agents. Consequently, it is proposed that the relationships between the onset time and the recovery may hardly expected in clinical practice following systemic administration of non-depolarizing neuromuscular blocking agents.
Adult ; Anesthesia ; Atracurium ; Humans ; Neuromuscular Blockade* ; Neuromuscular Blocking Agents ; Pancuronium ; Pipecuronium ; Succinylcholine ; Vecuronium Bromide