Rocuronium and Lidocaine Pretreatment for Prevention of Biochemical Changes, Fasciculations and Myalgia following Succinylcholine Administration / 대한마취과학회지

BACKGROUND: The purpose of this study was to assess the changes in serum potassium and creatine kinase concentrations and the incidence of fasciculations and myalgia when rocuronium and lidocaine were used in combination and separately as pretreatment before succinylcholine. METHODS: We studied 60 patients undergoing a minor elective surgery, in a prospective double blinded method. Three groups each with 20 patients were pretreated before a 1.5 mg/kg succinylcholine administration with 0.05 mg/kg rocuronium three min before (group R), 1.5 mg/kg lidocaine 30 sec before (group L), or both rocuronium and lidocaine (group RL). Serum potassium and creatine kinase were respectively measured 5 min after succinylcholine administration and 24 h after the operation. Fasciculations and myalgia on postoperative day 1 and day 2 were evaluated. RESULTS: The increase in creatine kinase and incidence of myalgia on postoperative day 1 was less in the RL group than in the R group and L group. The incidence of fasciculations was higher in the L group than in the R group and RL group. There was no increase in serum potassium in any group. CONCLUSIONS: The combined use of rocuronium and lidocaine was more effective in reducing creatine kinase and postoperative myalgia than when they were used separately. However, the fasciculations were only reduced by the use of rocuronium.

Appropriateness of Administering Rapid Tracheal Intubation with Rocuronium Using the Timing Principle / 대한마취과학회지

BACKGROUND: The "timing principle" utilises a single bolus of nondepolarizing neuromuscular blocking drug followed by an induction drug at the onset of clinical weakness. The purpose of this study was to compare the intubating conditions after succinylcholine or rocuronium and after rocuronium using the timing principle. METHODS: Forty patients were randomly allocated into four groups. Patients in group I received rocuronium 0.6 mg/kg using the timing principle. At the onset of clinical weakness, anesthesia was induced with the thiopental 4-5 mg/kg. Patients in group II, III, and IV received rocuronium 0.6, 0.9 mg/kg, and succinylcholine 1.5 mg/kg respectively using the usual technique. The trachea were intubated 60 s after thiopental induction. Accelerographic response to train-of-four (TOF) stimulation of the ulnar nerve was used for neuromuscular monitoring. Intubating conditions were assessed according to a grading scale. RESULTS: The twitch depression immediately before tracheal intubation in group I, II, III, and IV were 14.5, 28.2, 11.1, and 6.8%, respectively. The TOF count showed no significant differences between groups. The duration of action in group III (45.3 +/- 12.1 min) was significantly prolonged compared to that in group I (31.2 +/- 6.4 min). Intubation conditions were either good or exellent in all patients except one in group II. In group I, three patients recalled shortness of breath or general weakness. CONCLUSIONS: It is concluded that the use of rocuronium 2 X ED95 using the timing principle did not provide additional benefits compared to rocuronium 3 X ED95 using the usual technique except in duration.

The Effect of sium on the Onset Time of Rocuronium-Induced Neuromuscular Blockade in the Isolated Rat Phrenic Nerve-Hemidiaphragm / 대한마취과학회지

BACKGROUND: Magnesium sulfate (MgSO4) is widely used in the treatment of preeclamptic Hyperreflexia. Eclamptic convulsions are almost always prevented by MgSO4 in plasma concentrations of 4 to 7 mEq/L. It is well known that MgSO4 enhances the effect of nondepolarizing neuromuscular blockade. But the onset time of rocuronium is not shortened by MgSO4. METHODS: The effect of magnesium on the onset time of rocuronium-induced neuromuscular blockade was investigated in vitro rat phrenic nerve-hemidiaphragm preparation. The phrenic nerve-hemidiaphragm was dissected and suspended in an organ bath containing modified Krebs' solution and produced single twitch responses under 0.2 ms, 0.1 Hz, electrical stimulation. We added rocuronium until the twitch height decreased more than 95% of the initial level and determined a dose in 95% decrease twitch height as an effective concentration (EC95). After the administration of MgSO4, the onset time of neuromuscular blockade by rocuronium 1 x EC95, 1.5 x EC95, 2 x EC95 was compared with the onset time without MgSO4. RESULTS: EC50 and EC95 of rocuronium was 0.178 and 1.10 mg/dl. After administration of MgSO4, the concentration of Mg2 in the organ bath was 4.38 mEq/L. The onset time of the neuromuscular blockade by 1 x EC95 rocuronium was significantly shortened, but in the case of over 1.5 x EC95, it was not influenced by MgSO4. CONCLUSIONS: The concentration of Mg2 was within the therapeutic range for inhibition of uterine contraction. The onset time of rocuronium-induced neuromuscular blockade was shortened by magnesium but because a high dose of rocuronium was administered for intubation due to low potency and high plasma concentration, the effect of magnesium on the onset time of rocuronium seems to be masked. Therefore clinically, the onset time of rocuronium-induced neuromuscular blockade was not shortened by MgSO4.

Train-of-Four Fade Related to Potency during Recovery from Neuromuscular Block in Isolated Forearm / 대한마취과학회지

BACKGREOUND: The speed of action of nondepolarizing muscle relaxants might be correlated with the drug potency and the receptor-plasma concentration gradient. However, because of dissociation constants (KDs) being masked by plasma concentration following systemic administration, we investigated the degrees C of train-of-four (TOF) fade at various stages of the measured first twitch height of TOF (T1) during recovery related to potency of various muscle relaxants using isolated forearm technique. METHODS: Thirty two volunteers of the conscious healthy adults who were not receiving any medication which might have influence neuromuscular transmission were involved in this study. The electrodes were applied over the ulnar nerve at the wrist and supramaximal transcutaneous single twitch stimulation (0.1 Hz) delivered by a peripheral nerve stimulator (Innervator, Fisher & Paykel, New Zealand) using a 0.2 ms square wave pulses was applied. The twitch response of the thumb adductor was measured mechanomyographically using a 2 kg Load Cell strain gauge (Model No. 505H, RS Components Ltd., UK) with a thumb piece modification. Following a 5 min. period of stabilization, forearm pneumatic tourniquet was inflated to 300 mmHg in order to occlude the systemic circulation. The equipotent dose (ED95 0.1) of various muscle relaxants diluted in 20 ml of saline was injected into a vein on the dorsal hand respectively: rocuronium 30 microgram/kg, atracurium 25 microgram/kg, mivacurium 8 microgram/kg and vecuronium 4 microgram/kg. Eight volunteers received each dose. The forearm tourniquet was released at 3 min after drugs given. The neuromuscular block was allowed to recovery spontaneously, and at 25, 50, 75 and 100% recovery of control twitch height, TOF stimulation (2 Hz for 2 s) was administered in order to compare TOF ratios between musle relaxants. RESULTS: In the aminosteroid compounds, the TOF ratios of rocuronium were greater than those of vecuronium at all of the assessment points during recovery. In the benzylisoquinolium compounds, the TOF ratios of atracurium were greater than those of mivacurium at 25 and 50% recovery of control twitch height. CONCLUSION: The degree of TOF fade during recovery is related to drug potency at presynaptic receptors separated from the effects of plasma drug concentration.

Rocuronium Onset, Recovery and Effects on Blood Pressure and Heart Rates in Children Under O2- Propofol Anesthesia / 대한마취과학회지

BACKGROUND: Rocuronium(ORG 9426) is a new steroid nondepolarizing neuromuscular blocking drug with fast onset and intermittent duration of action. Its effects on vital signs are controversial. We studied onset, clinical duration, recovery index of rocuronium and its effects on blood pressures and heart rates. METHODS: We selected thirty healthy children who would receive inguinal herniorrhaphy and allocated them to 2 groups(control and rocuronium group). Without premedication or with oral medication of PocralTM (20 mg/kg), they administrated propofol(2.5 mg/kg) intravenous for loss of consciousness and we maintained anesthetic states with 20 mg/kg/hr of propofol. After 2 minutes, we checked BP(SBP/ DBP/MBP) and HR at every minutes and checked TOF, T1 height compare to control, T4 to T1 at every twenty seconds. We injected intravenously rocuronium(0.8 mg/kg, 2ED95) to rocuronium group and nothing to control group. We determined intubation time(from injection to 90% depression of maximal block), onset time(to maximal depression or T1=0), clinical duration(to T1=25%) and recovery index(from T1=25% to T1=75%). RESULTS: In children, intubation time was 93.8sec, onset time was 146.2sec, clinical duration was 34.6min, recovery index was 15.4min. SBP, DBP, MBP and HR were not changed independent of injection of rocuronium. CONCLUSION: Rocuronium is a muscle relaxant with rapid onset and intermittent clinical duration in children. It does not affect BP and HR.