Preventive Effects of Propofol Aganinst the Elevation of Intracellular Ca2+ and Reactive Oxygen Species Induced by Lysophosphatidic Acid in Endothelial Cells / 대한마취과학회지

BACKGROUND: This study was performed to examine 1) whether propofol prevented the increases in intracellular calcium and radical oxygen species (ROS) induced by lysophosphatidic acid (LPA) in endothelial cell; 2) whether these two types of increases were mediated by common underlying mechanisms. METHODS: Intracellular Ca2+ ([Ca2+]i) and H2O2 were measured in endothelial cell line (ECV 304) using a laser scanning confocal microscope. The cells, cultured and serum-starved on round coverslips, were incubated with various concentrations of propofol for 30 minutes, and then stimulated with various concentrations of LPA. The samples were excited by a 488 nm argon laser and images were filtered by a 515 nm longpass emission filter. The results were expressed as relative fluorescence intensity (RFI) and fold stimulation (fold). RESULTS: LPA increased in intracellular ROS in the endothelial cell in a dose-dependent manner. In addition, LPA-induced increase in ROS were alleviated by ROS scavengers such as Aspergillus niger catalase and n-(2-mercaptopropionyl)-glycine (2-MPG). LPA also increased in [Ca2+]i in a dose-dependent fashion. Propofol prevented LPA-induced increase in ROS and [Ca2+]i whereas 2-MPG did not affect the change of calcium level induced by LPA application. CONCLUSIONS: These results suggested that propofol prevented the increases in intracellular calcium and ROS induced by LPA in endothelial cell, and these two types of increases might be mediated by different underlying mechanisms.

Optimal Dosage of Propofol for Prevention of Increase in IOP during Rapid Sequence Induction with Endotracheal Intubation / 대한마취과학회지

BACKGROUND: Operations for patients with eye injuries frequently require rapid sequence induction of general anesthesia with succinylcholine (Sch), but Sch as well as endotracheal intubation produce increases in intraocular pressure (IOP). The purpose of this study was to examine whether the increase in dosage of propofol from a usual dosage would prevent the increase in IOP due to endotracheal intubation with Sch during a rapid sequence induction of general anesthesia. METHODS: Changes in IOP were measured in three groups of 15 patients each. The patients randomly received thiopental 5 mg/kg (group 1, n = 15), propofol 2.5 mg/kg (group 2, n = 15) or propofol 3.0 mg/kg (group 3, n = 15), followed by Sch 1.0 mg/kg and endotracheal intubation. IOP, systolic arterial pressure (SAP) and heart rate (HR) were measured before induction (baseline), just after intubation, 3 minutes and 10 minutes after intubation. RESULTS: IOP and SAP just after intubaton in groups 1 and 2 increased significantly from baseline, but did not increase significantly from baseline in group 3. IOP and SAP at 3 minutes after intubation in group 1 did not decrease significantly from baseline, but decreased significantly from baseline in groups 2 and 3. IOP and SAP at 10 minutes after intubaton in all groups decreased significantly from baseline. HR just after intubaton in groups 1 and 2 increased significantly from baseline, but did not increase significantly from baseline in group 3. HR at 3 minutes and 10 minutes after intubation in all groups did not change significantly from baseline. CONCLUSIONS: The authors concluded that propofol 3.0 mg/kg could prevent the increase in IOP, systolic arterial pressure and heart rate just after intubation during a rapid sequence induction of general anesthesia.

The Neuromuscular Blocking Effect of Mivacurium in Isolated Rat Phrenic-Hemidiaphragm with Long-term Phenytoin Pretreatment / 대한마취과학회지

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.

Pseudoaneurysm following Percutaneous Radial Artery Cannulation in a Diabetes Mellitus Patient: A Case Report / 대한마취과학회지

Insertion of indwelling arterial catheter has become a valuable procedure for blood pressure monitoring and for measurement of blood gas tension during anesthesia. A 34-year-old man with chronic alcoholism and diabetes mellitus was admitted to the hospital because of hyperosm-olar coma. On the first hospital day, percutaneous left radial artery cannulation was carried out for hemodynamic monitoring and arterial blood gas analysis after a modified Allen's test appear-ed to be positive. On the eleventh hospital day, the catheter was removed because of fever and sign of infection at the insertion site. Treatment with vancomycin by sensitivity test was begun on day 13, after continued for 2 weeks. On day 34 a pulsatile mass was noted at the insertion site. During surgery, a pseudoaneurysm of 1X1.2 cm size was found, and liquified hematoma and necrotic material were noted. The aneurysm was removed and end to end anastomosis was successfully completed. We suggest that risk factors for pseudoaneurysm may include abnormal state of vessel wall, multiple attempts at cannulation, increased duration of catheterization, adva-nced age, prolonged hospitalization, hematoma and infection at cannulation site.

Postoperative Sore Throat with Foam Cuffed Endotracheal Tube / 대한마취과학회지

BACKGROUND: Sore throat is a common complaint after endotracheal intubation and affected by several factors. The most important causes that affect the incidence and severity of postoperative sore throat is cuff overexpansion. We evaluate the incidence and severity of postoperative sore throat when foam-filled cuff endotracheal tubes and air-filled cuff endotracheal tubes are used. METHOD: Forty patients undergoing general endotracheal anesthesia were allocated randomly to two groups to receive either foam-filled cuff tubes or air-filled cuff tubes. All patients were interviewed 24 hours postoperatively whether they had experienced a sore throat or not by individuals who did not know which tube was used. RESULTS: Incidence of sore throat was 20% in foam-filled cuff group and 50% in air-filled cuff group. In foam-filled cuff group, sore throat was less severe than air-filled cuff group. In air- filled cuff group, sore throat was more severe as intracuff pressure was increased. CONCLUSION: The incidence and severity of postoperative sore throat could be significantly reduced using the foam-filled cuff tubes.

Optimum Dose of Pipecuronium with a Intravenous Bolus Injection for Endotracheal Intubation in Adults / 대한마취과학회지

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.

The Effects of Magnesium on Pipecuronium-induced Neuromuscular Blockade and its Reversal in the Isolated Rat Phrenic Nerve-Hemidiaphragm / 대한마취과학회지

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.