Effects on Intubating Conditions of Pretreatment with Remifentanil before Administration of Cisatracurium / 전남의대학술지

Cisatracurium provides superior hemodynamic stability with only minor release of histamine, and its metabolism via Hoffman elimination is independent of organ function. However, use of cisatracurium is limited because of reportedly slower onset and unsatisfactory intubating conditions. Many studies have shown that remifentanil might provide reliable intubating conditions; thus, we hypothesized that pretreatment with remifentanil before administration of cisatracurium might result in acceptable intubating conditions. Sixty healthy patients scheduled for elective surgery were enrolled and randomly divided into three groups: saline (Group I, n=20), remifentanil 0.5 microg/kg (Group II, n=20), and remifentanil 1.0 microg/kg (Group III, n=20). The anesthesia was induced with propofol 2.0 microg/kg given intravenously over 30 s followed by injection over 30 s of a different dose of remifentanil according to the study protocol. We examined the intubating condition by jaw relaxation, vocal cord state, and diaphragmatic response 90 s after administering cisatracurium. We also measured mean blood pressure, heart rate, and the onset time, which is the interval from the end of neuromuscular blocking agent administration until suppression of maximal T1 on a train-of four sequence. The mean values of the intubating condition after endotracheal intubation in Groups II and III were significantly lower than that in Group I (p<0.005), although the overall onset time of cisatracurium did not differ significantly between the three groups. Our results suggest that supplementation with remifentanil in an induction regimen with cisatracurium improves the quality of the intubating condition even though the onset time of cisatracurium is not shortened.

Effects on Intubating Conditions of Pretreatment with Remifentanil before Administration of Cisatracurium / 전남의대학술지

Cisatracurium provides superior hemodynamic stability with only minor release of histamine, and its metabolism via Hoffman elimination is independent of organ function. However, use of cisatracurium is limited because of reportedly slower onset and unsatisfactory intubating conditions. Many studies have shown that remifentanil might provide reliable intubating conditions; thus, we hypothesized that pretreatment with remifentanil before administration of cisatracurium might result in acceptable intubating conditions. Sixty healthy patients scheduled for elective surgery were enrolled and randomly divided into three groups: saline (Group I, n=20), remifentanil 0.5 microg/kg (Group II, n=20), and remifentanil 1.0 microg/kg (Group III, n=20). The anesthesia was induced with propofol 2.0 microg/kg given intravenously over 30 s followed by injection over 30 s of a different dose of remifentanil according to the study protocol. We examined the intubating condition by jaw relaxation, vocal cord state, and diaphragmatic response 90 s after administering cisatracurium. We also measured mean blood pressure, heart rate, and the onset time, which is the interval from the end of neuromuscular blocking agent administration until suppression of maximal T1 on a train-of four sequence. The mean values of the intubating condition after endotracheal intubation in Groups II and III were significantly lower than that in Group I (p<0.005), although the overall onset time of cisatracurium did not differ significantly between the three groups. Our results suggest that supplementation with remifentanil in an induction regimen with cisatracurium improves the quality of the intubating condition even though the onset time of cisatracurium is not shortened.

Comparison of intubating conditions according to different doses of rocuronium during propofol-remifentanil target controlled infusion / 대한마취과학회지

BACKGROUND: Many studies have shown that tracheal intubation can be facilitated by propofol-remifentanil without muscle relaxant. But low dose of rocuronium can improve intubating condition and reduce the requirement of remifentanil. This study evaluated the optimal dose of rocuronium for tracheal intubation according to different doses of rocuronium during propofol-remifentanil target controlled infusion (TCI). METHODS: Sixty, ASA I-II patients were randomly divided into three groups (n = 20). Anesthesia was induced with remifentanil 3.0 ng/ml and propofol 3.5 microgram /ml target controlled infusion. After patients lost consciousness, rocuronium was administrated 0.6 mg/kg (R0.6), 0.45 mg/kg (R0.45), 0.3 mg/kg (R0.3) for each group. Three minutes later, a laryngoscope and tracheal intubation were tried, intubating condition were measured. Also blood pressure and heart rate were measured before induction, preintubation, postintubation. RESULTS: Clinically acceptable intubation condition (excellent or good) were observed 100%, 100%, 85% of patients in the R0.6, R0.45, and R0.3 groups. Eighty five percents of patients in groups R0.6, R0.45 had excellent intubation condition. But only 35% in group R0.3 showed excellent intubating condition (P < 0.05) and 15% in group R0.3 showed poor intubating condition. There were no significant elevation mean blood pressure (MBP), heart rate (HR) after tracheal intubation in all groups. And there were no significant differences among groups. CONCLUSIONS: The optimal dose of rocuronium for clinical acceptable intubating condition could be reduced to 1.5 x ED(95) under total intravenous anesthesia with remifentanil 3.0 ng/ml and propofol 3.5 microgram/ml target controlled infusion.

Effect-site concentration of remifentanil for smooth tracheal intubation without muscle relaxants provokes hypotension under desflurane anesthesia / 대한마취과학회지

BACKGROUND: Many reports with hypnotics and opiates have been published for nonrelaxant tracheal intubation.In addition to its immediate onset and short duration time, remifentanil can well prevent responses against short and strong stimulation like tracheal intubation.However, the high concentration of remifentanil for nonrelaxant tracheal intubation can cause hemodynamic instability, thus we tried to estimate the predicted effect-site concentration of remifentanil for smooth intubation and provoking hypotension. METHODS: Forty three ASA I and II patients were randomly selected to receive an effect-site-controlled infusion of remifentanil 0, 2, 4, 6 ng/ml and propofol 2 mg/kg.Trachea was intubated after 3 minutes of manual breathing support with desflurane 6 vol%. The vital signs, end-tidal concentration of desflurane and responses of patients were recorded before intubation for 3 minutes and until 2 minutes after intubation every minute.The effective effect-site concentration (ECe) was calculated at 95% successful rate of smooth intubation and at 50% of provoking hypotension (equal to or under 55 mmHg). RESULTS: The estimation results of the logistic regression stated that 95% ECe of remifentanil for smooth intubation was 8.0 (5.0-14.3) ng/ml and 50% ECe for provoking hypotension equal to or under 55 mmHg before intubation was 5.0 (2.6-9.7) ng/ml. CONCLUSIONS: Remifentanil at 8.0 ng/ml provided good conditions for smooth intubation without muscle relaxants but could provoked hypotension.Consequently, we recommend the careful observation of the blood pressure with the use of remifentanil and the evaluation of the suitable measures to maintain the blood pressure for nonrelaxant tracheal intubation.

Effect of Storage Temperature of Rocuronium on Intubating Condition and Clinical Duration after Low-dose Technique / 대한마취과학회지

BACKGROUND: Rocuronium bromide is a monoquaternary amino steroidal muscle relaxant. Rocuronium is structurally stable and no metabolites of rocuronium have not been observed in humans. The manufacturer recommends that rocuronium can be stored in room temperature for 12 weeks. The aim of this study was to determine if the storage temperature of rocuronium could influence the pharmacodynamics of rocuronium. METHODS: One hundred of patients with a class I or II ASA physical status were enrolled in this study. It was divided to two groups. One (Group '0', n = 50) consists of those who had intravenously administered the rocuronium which had been stored in refrigerator and the other (Group '14', n = 50) consists of those who had intravenously administered the rocuronium which had been stored in room temperature (20-29degrees C, median 25.1degrees C) for 14 days. Before an anesthesia was induced, TOF-Watch(R) was attached and calibrated. The anesthesia was induced with 1microgram/kg of fentanyl and 1.5 mg/kg of propofol intravenously. While the 0.1 Hz of single twitch was applied, 0.45 mg/kg of rocuronium, which is appointed to each group, was injected. Intubation is performed 90 seconds after injection of rocuronium and evaluated the intubating condition as excellent, good, poor, and impossible. RESULTS: There was a statistically significant difference in intubating condition at 90 seconds between two groups. The onset time to twitch depression of 0% in group '14' was prolonged compared to group '0' (P < 0.05). Clinical duration was also shortened in group '14' (P < 0.05). CONCLUSIONS: Compared with the use of rocuronium stored in refrigerator, that stored at room temperature can be expected to have unfavorable intubating condition at 90 seconds after rocuronium injection. Therefore, the storage temperature has some influences on the efficacy of rocuronium.

Tracheal Intubation without the Use of Muscle Relaxants: Remifentanil in Combination with Propofol / 대한마취과학회지

BACKGROUND: Using alfentanil followed by an anesthetic induction dose of propofol provides adequate conditions for tracheal intubation without neuromuscular blocking drugs in most patients. Providing an option for intense opioid effect without compromising recovery after short operations, remifentanil might offer benefits over alfentanil. In this study intubating conditions after remifentanil-propofol were evaluated. METHODS: Sixty healthy premedicated patients were divided randomly into 3 groups. Anesthesia was intravenously induced with propofol (4 microgram/ml) followed by remifentanil. Group R(2), R(3), R(4) received 2, 3, 4 microgram/kg remifentanil, respectively. Ninety seconds after the administration of remifentanil, laryngoscopy and intubation were attempted. Intubation conditions were assessed as excellent, good or poor. The hemodynamic changes were measured at preinduction (base), preintubation, postintubation (immediately, 3 minute, 5 minute after intubation). RESULTS: Clinically acceptable intubating conditions were observed in 65%, 95%, and 95% of patients in the R(2), R(3), and R(4) groups, respectively. Clinically acceptable intubating conditions were significantly (P < 0.05) less likely to occur in Group R(2). The mean arterial pressure decreased immediately after induction in all groups. There was no significant elevation in heart rate after tracheal intubation in all groups. There were no significant differences among groups. CONCLUSIONS: Healthy, premedicated patients with favorable airway anatomy can be reliably intubated with good or excellent conditions 90 seconds after the administrations of remifentanil 3-4 microgram/kg and propofol.

Intubating Conditions and Hemodynamic Changes according to Induction Agent and Tracheal Intubation Time after Rocuronium / 대한마취과학회지

BACKGROUND: Intubating conditions would be excellent and hemodynamic variables would be relatively stable during rapid- sequence anesthesia induction if tracheal intubation was performed at a proper time. The purpose of this study was to identify the ideal intubation time after rocuronium with either thiopental or propofol. METHODS: 113 patients, ASA physical status I or II, were randomly divided into four groups. Patients in group TR60 (thiopental-rocuronium) and in group PR60 (propofol-rocuronium) were intubated within 60 s, while groups TR90 and PR90 were intubated within 90 s after the administration of rocuronium. Intubating conditions were graded by an experienced anesthesiologist, and hemodynamic variables were noted just before induction (baseline), immediate after induction, immediate after intubation, and 5 min after intubation. RESULTS: Clinically acceptable intubating conditions (good or excellent) were not statistically different among the four groups. However, 55 and 64% of patients in groups TR90 and PR90, respectively, had excellent intubating conditions compared to only 39 and 38% in groups TR60 and PR60 (P < 0.05). Mean arterial pressure and rate pressure product (RPP) immediately after intubation were relatively stable in groups TR90 and PR90 compared to those in groups TR60 and PR60 (P < 0.05). CONCLUSIONS: The intubation time after rocuronium, rather than the choice of induction agent, is the deciding factor affecting intubating conditions and hemodynamic variables during rapid-sequence anesthesia induction. Ninety seconds after the administration of rocuronium with either thiopental or propofol might be an ideal intubation time.

Clinical Study of the Onset Time of Rocuronium / 대한마취과학회지

BACKGROUND: Rocuronium, a new nondepolarizing muscle relaxant, has been reported to develop a rapid onset of action and may be suitable as a component of a rapid-sequence induction of anesthesia. Therefore we have compared rocuronium with pancuronium and vecuronium about the onset time, intubation time, and tracheal intubating conditions. METHOD: Thirty patients were divided into three groups, who were receiving intravenously pancuronium 0.14 mg/kg, vecuronium 0.1 mg/kg and rocuronium 0.6 mg/kg respectively for tracheal intubation during induction of anesthesia. The onset time(Time from drug administration to zero count of PTC) and intubation time were checked using train of four responses of the adductor pollicis muscle after ulnar nerve stimulation(2 Hz, 40mA) every 10 seconds. The intubation conditions were recorded by a "blinded" assessor as excellent, good, fair or not possible. RESULT: The onset time of pancuronium, vecuronium and rocuronium was, 125.0+/-10.0, 256.0+/-18.4 and 90.0+/-22.1 sec. respectivly. The time of intubation was 94.0+/-12.6, 95.3+/-7.9, and 77.0+/-10.6sec.(pancuronium,vecuronium & rocuronium respectively). The onset time of rocuronium was significantly faster than the other two nondepolarizing muscle relaxants. The tracheal intubation with rocuronium was possible earlier than pancuronium or vecuronium but no statistical significance was observed and the condition of intubation was excellent compare to others in all ten patients. CONCLUSION: Rocuronium may have advantages over existing non-depolarizing neuromuscular blocking agents with faster rate of development of neuromuscular block with excellent intubation condition after administraction of a dose 0.6 mg/kg(ED 95 x 2).

Clinical Study of the Onset Time of Rocuronium / 대한마취과학회지

BACKGROUND: Rocuronium, a new nondepolarizing muscle relaxant, has been reported to develop a rapid onset of action and may be suitable as a component of a rapid-sequence induction of anesthesia. Therefore we have compared rocuronium with pancuronium and vecuronium about the onset time, intubation time, and tracheal intubating conditions. METHOD: Thirty patients were divided into three groups, who were receiving intravenously pancuronium 0.14 mg/kg, vecuronium 0.1 mg/kg and rocuronium 0.6 mg/kg respectively for tracheal intubation during induction of anesthesia. The onset time(Time from drug administration to zero count of PTC) and intubation time were checked using train of four responses of the adductor pollicis muscle after ulnar nerve stimulation(2 Hz, 40mA) every 10 seconds. The intubation conditions were recorded by a "blinded" assessor as excellent, good, fair or not possible. RESULT: The onset time of pancuronium, vecuronium and rocuronium was, 125.0+/-10.0, 256.0+/-18.4 and 90.0+/-22.1 sec. respectivly. The time of intubation was 94.0+/-12.6, 95.3+/-7.9, and 77.0+/-10.6sec.(pancuronium,vecuronium & rocuronium respectively). The onset time of rocuronium was significantly faster than the other two nondepolarizing muscle relaxants. The tracheal intubation with rocuronium was possible earlier than pancuronium or vecuronium but no statistical significance was observed and the condition of intubation was excellent compare to others in all ten patients. CONCLUSION: Rocuronium may have advantages over existing non-depolarizing neuromuscular blocking agents with faster rate of development of neuromuscular block with excellent intubation condition after administraction of a dose 0.6 mg/kg(ED 95 x 2).

The Comparison of Vecuronium with Succinylcholine for Endotracheal Intubation / 대한마취과학회지

Depolarizing muscle relaxant, succinylcholine, has a rapid onset of action, allowing early endotracheal intubation. Succinylcholine, however, has a number of undesirable side effects. Therefore, some methods using nondepolarizing muscle relaxants for rapid endotracheal intubation have been tried, i.e. single large bolus, priming principle, timing principle, but their results were not enough to satisfy. In this study, there were administered vecuronium prior to anesthetic induction in order to shorten the intubation time, and compared intubation time and intubating condition in succinylcholine and vecuronium groups respectively. Sixty adult patients were adminstered succinylcholine 1mg/kg(group 1, 30 patients) or vecuronium 0.15 mg/kg(group 2, 30 patients), and measured intubation time and intubating condition. As a result, intubation time and intubation condition was not different in both groups significantly. It is concluded that vecuronium administered prior to induction agent for the endotracheal intubation is a reliable alternative in cases where succinylcholine is contraindicated.

The Comparison of Vecuronium with Succinylcholine for Endotracheal Intubation / 대한마취과학회지

Depolarizing muscle relaxant, succinylcholine, has a rapid onset of action, allowing early endotracheal intubation. Succinylcholine, however, has a number of undesirable side effects. Therefore, some methods using nondepolarizing muscle relaxants for rapid endotracheal intubation have been tried, i.e. single large bolus, priming principle, timing principle, but their results were not enough to satisfy. In this study, there were administered vecuronium prior to anesthetic induction in order to shorten the intubation time, and compared intubation time and intubating condition in succinylcholine and vecuronium groups respectively. Sixty adult patients were adminstered succinylcholine 1mg/kg(group 1, 30 patients) or vecuronium 0.15 mg/kg(group 2, 30 patients), and measured intubation time and intubating condition. As a result, intubation time and intubation condition was not different in both groups significantly. It is concluded that vecuronium administered prior to induction agent for the endotracheal intubation is a reliable alternative in cases where succinylcholine is contraindicated.