Onset time, duration of action, and intubating conditions after mivacurium in elderly and younger patients.

BACKGROUND: The neuromuscular blocking agent mivacurium can be used during anesthesia to facilitate tracheal intubation. Data on onset time, duration of action, and effect on intubating conditions in patients 80 years and older are however limited. We hypothesized that onset time and duration of action of mivacurium would be longer in elderly patients than in younger adults. METHODS: This prospective observational study included 35 elderly (≥80 years) and 35 younger (18-40 years) patients. Induction of anesthesia comprised fentanyl 1-3 µg kg-1 and propofol 1.5-2.5 mg kg-1 and propofol and remifentanil for maintenance. Acceleromyography was used for monitoring neuromuscular blockade. The primary outcome was onset time defined as time from injection of mivacurium 0.2 mg kg-1 to a train-of-four (TOF) count of zero. Other outcomes included duration of action (time to TOF ratio ≥0.9), intubating conditions using the Fuchs-Buder scale and the intubating difficulty scale (IDS), and occurrence of hoarseness and sore throat postoperatively. RESULTS: No difference was found in onset time comparing elderly with younger patients; 219 s (SD 45) versus 203 s (SD 74) (difference: 16 s (95% CI: -45 to 14), p = .30). Duration of action was significantly longer in elderly patients compared with younger patients; 52 min (SD 17) versus 30 min (SD 8) (difference: 22 min [95% CI: 15 to 28], p < .001). No difference was found in the proportion of excellent intubating conditions (Fuchs-Buder); 31/35 (89%) versus 26/35 (74%) (p = .12) or IDS score (p = .13). A larger proportion of younger patients reported sore throat 24 h postoperatively; 34% versus 0%, p = .0002. No difference was found in hoarseness. CONCLUSION: No difference in onset time of mivacurium 0.2 mg kg-1 was found comparing elderly and younger patients. However, elderly patients had significantly longer duration of action. No difference was found in intubating conditions.

Comparison of Intubating Conditions at 60 Seconds with Cisatracurium 4*ED95 Dose and Cisatracurium 2*ED95 Dose Plus Priming Dose and Low Dose Ketamine.

Introduction: To compare the intubating conditions at 60 seconds between 4*ED95 dose of cisatracurium and 2*ED95 dose of cisatracurium in combination with priming and low dose ketamine. Primary Objective: jaw relaxation for laryngoscopy, vocal cord position on laryngoscopy, and coughing or bucking response to intubation. Secondary Objective: To compare the hemodynamic changes up 10 minutes after intubation in the two groups. In this prospective study, a total of 68 patients were undergoing general anesthesia for surgery with placement of endotracheal tube placement. Patients will be divided into two groups comprising 34 patients each. The patients were allocated one of the two groups by computerized randomization. *Group A received bolus dose of cisatracurium which is 0.2 mg/kg (4*ED95). **Group B received cisatracurium in dose of 0.1 mg/kg (2*ED95) with priming (which is 10% of the bolus dose) and low dose ketamine of about 0.5 mg/kg. It was possible to achieve acceptable laryngoscopy and intubating condition in both the groups within 90 seconds. When grades of laryngoscopy and ease of intubation were compared, 2*ED95 dose along with priming plus low dose ketamine produced superior results than 4*ED95 group. When the mean arterial pressure and pulse rate were compared between the two groups, it was observed that mean arterial pressure and pulse rate were only slightly higher in the 2*ED95 along with priming and ketamine.

Tracheal intubating conditions in elderly patients when train-of-four count is zero after rocuronium 0.6 or 0.9 mg/kg. A secondary analysis.

PURPOSE: The neuromuscular blocking agent rocuronium can be administered to facilitate tracheal intubation. We hypothesized that rocuronium 0.9 mg/kg provided a larger proportion of patients with vocal cords in abducted position compared to rocuronium 0.6 mg/kg at train-of-four (TOF) 0. METHODS: This secondary analysis was based on 52 elderly surgical patients of which 36 patients received rocuronium 0.6 mg/kg and 16 patients received rocuronium 0.9 mg/kg. Neuromuscular block was monitored with acceleromyography with TOF stimulation at the ulnar nerve. The primary outcome was the proportion of patients with vocal cords in abducted position at TOF 0. Secondary outcomes were intubating conditions evaluated by the Fuchs-Buder scale, the Intubating Difficulty Score (IDS), onset time, and duration of action of rocuronium. RESULTS: At TOF 0, a significantly larger proportion of patients had vocal cords in abducted position in the rocuronium 0.9 mg/kg group (81%) compared with the rocuronium 0.6 mg/kg group (53%); difference (%) 28, 95% Cl 3-53, P = 0.05. Excellent intubating conditions (Fuchs-Buder) were more common in the rocuronium 0.9 mg/kg group (62.5%); difference (%) 32.5, 95% Cl 4-61), P = 0.03. No significant difference was found in IDS or onset time of rocuronium (difference 19 s, 95% Cl: -5-43). Duration of action was significantly longer (difference 29 min, 95% Cl: 10-47) in the 0.9 mg/kg group. CONCLUSION: The proportion of patients with vocal cords in abducted position was significantly larger after rocuronium 0.9 mg/kg compared to rocuronium 0.6 mg/kg at TOF 0 monitored at the ulnar nerve.

A Comparative Study between Propofol-fentanyl versus Propofol-suxamethonium for Ease of Endotracheal Intubation in Children.

Background: Following propofol induction, suxamethonium tremendously improves intubating conditions in children and has been the gold standard agent for this purpose. However, suxamethonium could be absolutely contraindicated in some patients. Fentanyl, a short acting opioid, has been investigated as a suitable alternative with varying results. Aim and Objectives: This study compares the ease of tracheal intubation between propofol-suxamethonium (1.5 mg/kg) and propofol-fentanyl (3 mcg/kg) during general anaesthesia among children. Patients and Methods: In this double-blind randomised controlled study, 84 ASA I or II patients booked for elective surgery under general anaesthesia requiring tracheal intubation were randomised into two groups (F and S). Induction was with propofol 3 mg/kg over 30 s followed by either fentanyl 3 mcg/kg or suxamethonium 1.5 mg/kg. Two minutes later, there was an attempt at intubation and intubating conditions were assessed using Steyn's modification of Helbo-Hansen's score (ease of laryngoscopy, jaw relaxation, coughing, vocal cord position, and limb movement). Results: All patients in both groups had successful intubation at the first attempt. Patients in group S (suxamethonium) had significantly better overall intubating conditions compared to those in group F (fentanyl) (p=0.0001), 85.7% in group S compared to 21.4% in group F had excellent intubation condition. None of the patients in the two groups demonstrated fair or poor intubation condition. Conclusion: A combination of propofol-fentanyl can be used as an alternative to propofol-suxamethonium to ease intubation in paediatric patients.

Comparison of onset time, duration of action, and intubating conditions after cisatracurium 0.15 mg/kg in young and elderly patients.

INTRODUCTION: Tracheal intubation during anesthesia can be facilitated by the neuromuscular blocking agent cisatracurium. However, limited data exists about onset time, duration of action and effect on intubating conditions in elderly patients above 80 years of age. We hypothesized that elderly patients would present a longer onset time and duration of action compared to younger adults. METHODS: This prospective observational study included 31 young (18-40 years) and 29 elderly (≥ 80 years) patients. Patients were given fentanyl 2 µg/kg and propofol 1.5-2.5 mg/kg for induction of anesthesia and maintained with remifentanil and propofol. Monitoring of neuromuscular function was performed with acceleromyography. Primary outcome was onset time defined as time from injection of cisatracurium 0.15 mg/kg (based on ideal body weight) to a train-of-four (TOF) count of 0. Other outcomes included duration of action (time to TOF ratio ≥ 0.9), intubation conditions using the Fuchs-Buder scale and the Intubating Difficulty Scale (IDS), and occurrence of hoarseness and sore throat postoperatively. RESULTS: Elderly patients had significantly longer onset time compared with younger patients; 297 seconds (SD 120) vs. 199 seconds (SD 59) (difference: 98 seconds (95% CI: 49-147), P < 0.001)). Duration of action was also significantly longer in elderly patients compared with younger patients; 89 minutes (SD 17) vs. 77 minutes (SD 14) (difference: 12 minutes (95% CI: 2.5-20.5) P = 0.01)). No difference was found in the proportion of excellent intubating conditions (Fuchs-Buder); 19/29 (66%) vs 21/31 (68%) (P = 0.86) or IDS score (P = 0.74). A larger proportion of elderly patients reported hoarseness 24 hours postoperatively; 62% vs 34% P = 0.04. CONCLUSION: In elderly patients cisatracurium 0.15 mg/kg had significantly longer onset time and duration of action compared with younger patients. No difference was found in intubating conditions at a TOF count of 0. TRIAL REGISTRATION: Clinicaltrials.gov (NCT04921735, date of registration 10 June 2021).

A blinded randomized study comparing intubating conditions after either rocuronium 0.6 mg·kg-1 or remifentanil 2 µg·kg-1 in elderly patients.

BACKGROUND: To facilitate tracheal intubation, either a neuromuscular blocking agent or a bolus dose of remifentanil can be administered. We hypothesized that rocuronium 0.6 mg·kg-1 provided a larger proportion of excellent intubating conditions compared to remifentanil 2 µg·kg-1 in patients above 80 years. METHODS: A total of 78 patients were randomized to either rocuronium 0.6 mg·kg-1 or remifentanil 2 µg·kg-1 . General anaesthesia was initiated with fentanyl and propofol. Two minutes after the administration of either rocuronium or remifentanil, tracheal intubating conditions were evaluated using the Fuchs-Buder scale by a blinded investigator, and our primary outcome was the proportion of patients presenting intubating conditions deemed as excellent. Further outcomes included the Intubating Difficulty Scale (IDS), hoarseness or sore throat 24 h postoperatively, and intervention against hypotension. RESULTS: No difference in the occurrence of excellent intubating conditions was found comparing the rocuronium group with the remifentanil group; 10 (28%) versus 15 (39%) (p = .29), respectively, relative risk = 0.72. Interventions against hypotension were used in 24 (67%) versus 28 (74%) (p = .51), respectively. Hoarseness and sore throat 24 h postoperatively were found in 37% versus 35% p = .86, and 14% versus 5% p = .20, respectively. The IDS score was 2 versus 2 p = .48. CONCLUSION: No difference in intubating conditions was found 2 min after the administration of either rocuronium 0.6 mg·kg-1 or remifentanil 2 µg·kg-1 in patients aged above 80 years. Intubation conditions were less than optimal in a large proportion of this patient population. CLINICAL TRIALS REGISTRATION: NCT04287426.

High-dose rocuronium-induced paralysis of the adductor pollicis muscle facilitates detection of the timing for tracheal intubation in elderly patients: a randomized double-blind study.

PURPOSE: To prevent coughing related to tracheal intubation and the resultant exposure of intubating staff to the patients' expiratory aerosols, the timing of tracheal intubation needs to be precisely predicted. The aim of this study was to evaluate the hypothesis that the timing for safe tracheal intubation in elderly patients can be determined by acceleromyographically monitoring paralysis of the adductor pollicis muscle when high-dose rocuronium, given to block the respiratory muscles, is administered. METHODS: Forty elderly (65-92 years) patients were enrolled in this study and randomly assigned to two groups, to receive rocuronium 0.6 mg/kg or 1 mg/kg. After induction of anesthesia and observing acceleromyographic train-of-four (TOF) responses of the adductor pollicis muscle to ulnar nerve stimulation, the patients randomly received either dose of rocuronium. The onset times from rocuronium administration to TOF counts of 0 were measured. Soon thereafter, a single anesthesiologist who was blinded to the allocated dose of rocuronium performed laryngoscopy and tracheal intubation, and assessed intubating conditions. Data were analyzed by the unpaired t-test and Chi-squared test. RESULTS: The averaged [SD] onset time of neuromuscular blockade was significantly shorter with 1 mg/kg than 0.6 mg/kg rocuronium (104.3 [30.1] s vs. 186.8 [37.5] s, p < 0.001). Patients who received 0.6 mg/kg rocuronium variously showed either poor (n = 9) or good (n = 11) intubating conditions. However, all patients who received 1 mg/kg rocuronium had excellent intubating conditions. CONCLUSIONS: If 1 mg/kg rocuronium is administered, a TOF count of 0 acceleromyographically observed at the adductor pollicis muscle can reveal the adequate timing for tracheal intubation.

Therapeutic Efficacy of Two Different Doses of Dexmedetomidine on the Hemodynamic Response to Intubation, the Intubating Conditions, and the Effect on the Induction Dose of Propofol: A Randomized, Double-Blind, Placebo-Controlled Study.

CONTEXT: The hemodynamic response associated with laryngoscopy and tracheal intubation is a common concern for the anesthesiologist, especially in high-risk patients. The use of dexmedetomidine has found favor in obtunding this response, in addition to providing better intubating conditions and reducing the dose of other anesthetic drugs. Most of the current literature states a loading dose of 1 µg/kg dexmedetomidine to be superior to lower doses in this regard. However, using a lower dose may be advantageous by reducing incidence of adverse effects such as hypotension and bradycardia which are likelier with the use of higher dose, in addition to being more cost-effective. AIMS: The aim of the study was (1) to evaluate and compare the effect of loading doses of 1 µg/kg and 0.5 µg/kg dexmedetomidine on attenuation of hemodynamic response to laryngoscopy and intubation and (2) to evaluate the efficacy of dexmedetomidine in reducing the induction dose of propofol for achieving better intubating conditions. MATERIALS AND METHODS: A randomized, double-blind, placebo-controlled study was planned on ninety American Society of Anesthesiologists I and II patients scheduled for elective surgery under general anesthesia. Patients were divided into three groups. Two groups received different loading doses of dexmedetomidine infusion before induction and the third group was a control group. The induction dose of propofol required to abolish the verbal response was noted and compared in all the three groups. All patients were assessed for the intubating conditions and hemodynamic response. STATISTICAL ANALYSIS: Nonparametric data were compared using the Chi-square test and parametric data were compared using Student's t-test using SPSS 16.0 software. RESULTS: Both the loading doses of 1 µg/kg and 0.5 µg/kg dexmedetomidine were equally effective in reducing the induction dose of propofol, improving the intubating conditions and blunting the hemodynamic response to laryngoscopy and intubation. The incidence of adverse effects such as hypotension and bradycardia was lesser with the loading dose of 0.5 µg/kg. CONCLUSIONS: Dexmedetomidine when used as infusion in the loading dose of 0.5 µg/kg is therapeutically as effective as when used in the dose of 1.0 µg/kg not only in reducing the induction dose of propofol but also in providing good intubating conditions and blunting the hemodynamic response to intubation. A lower dose is associated with a lesser incidence of adverse effects such as hypotension and bradycardia.

A comparison of haemodynamic responses between clinical assessment-guided tracheal intubation and neuromuscular block monitoring-guided tracheal intubation: A prospective, randomised study.

BACKGROUND AND AIMS: Haemodynamic responses to laryngoscopy and endotracheal intubation and their hazards are well documented. The purpose of the study was to compare the effects of laryngoscopy and intubation on cardiovascular responses when the appropriate moment for intubation was directed by either clinical judgment or train-of-four assessment. METHODS: A total of 68 patients, posted for laparoscopic cholecystectomy, were randomised into two groups. In Group M patients, the trachea was intubated after train of four counts became zero in adductor pollicis muscle, whereas in Group C patients, the trachea was intubated after the clinical judgment of jaw muscle relaxation. Changes in heart rate (HR) and mean arterial pressure, intubating conditions and the time between the administration of a neuromuscular blocking agent and endotracheal intubation were recorded. Results were analysed by the Analysis of variance and chi-square tests. RESULTS: HR and mean arterial pressure were significantly higher in Group C as compared to Group M after laryngoscopy and tracheal intubation (P < 0.05). The mean time required for intubation was significantly shorter in Group C compared to Group M (175 ± 7 s vs. 385 ± 101 s). Excellent and good intubation conditions were observed in all Group M patients, whereas 24 out of 34 patients (70%) in Group C showed excellent and good intubation conditions. CONCLUSION: Haemodynamic responses to laryngoscopy and tracheal intubation can be significantly attenuated if tracheal intubation is performed following complete paralysis of laryngeal muscles, detected by neuromuscular monitoring of adductor pollicis muscle.

Comparison of the trapezius and the adductor pollicis muscle as predictor of good intubating conditions: a randomized controlled trial.

BACKGROUND: Adequate muscle relaxation is important for ensuring optimal conditions for intubation. Although acceleromyography of the adductor pollicis muscle is commonly used to assess conditions for intubation, we hypothesized that acceleromyography of the trapezius is more indicative of optimal intubating conditions. The primary outcome was the difference between both measurement sites with regard to prediction of good or acceptable intubating conditions. METHODS: Neuromuscular blockade after injection of rocuronium 0.3 mg/kg IV was measured simultaneously with acceleromyography of the adductor pollicis muscle and the trapezius muscle in sixty female patients, American Society of Anesthesiologists physical status I to III, undergoing general anesthesia for gynecologic surgery. Exclusion criteria were: expected difficult tracheal intubation (e.g. history of difficult intubation, reduced mouth opening (< 2 cm) and/or Mallampati Score 4), increased risk of pulmonary aspiration (e.g. gastroesophageal reflux or delayed gastric emptying) allergies to drugs used during the study, pregnancy, neuromuscular diseases, medication with potential to influence neuromuscular function (e.g. furosemide, magnesium, cephalosporins) and hepatic or renal insufficiency (serum bilirubin >26 µmol/L, serum creatinine >90 µmol/l). Patients were randomized to 2 groups: group A (n = 30): endotracheal intubation after onset of the neuromuscular block at the adductor pollicis muscle. Group B (n = 30): endotracheal intubation after onset at the trapezius muscle. Intubating conditions were compared between both groups by means of a standardised score (the Copenhagen score) with Fisher's exact test. RESULTS: Onset of the block after rocuronium injection was observed at the adductor pollicis muscle compared to the trapezius with 2.8 (1.1) versus 2.5 (1.1) min (mean ± SD; P = 0.006). Intubating conditions were poor in 2 patients (7%) of group A, and in 1 patient (3%) of group T. They were acceptable (either excellent or good) in 28 patients (93%) in group A, and in 1 patient (97%) in group T (P = 0.82). CONCLUSIONS: Performing acceleromyography at the trapezius muscle reduced the time between injection of neuromuscular blocking agents and intubation by 18 s (11%). Thus, trapezius muscle acceleromyography is an acceptable alternative to adductor pollicis muscle acceleromyography in predicting acceptable intubating conditions, which allows for earlier indication of adequate intubating conditions. TRIAL REGISTRATION: ClinicalTrial.gov Identifier: NCT01849198 . Registered April 29, 2013.

Comparison of Effect of Ephedrine and Priming on the Onset Time of Vecuronium.

BACKGROUND: Succinylcholine has been the neuromuscular blocking drug of choice for laryngoscopy and intubation, but it has several adverse effects. Nondepolarizing neuromuscular blocking drugs are good alternative provided their onset of action is hastened. Priming technique and use of ephedrine or MgSO4 pretreatment is good options. AIMS: To compare the effects of priming and ephedrine pretreatment on the onset time of intubating dose of vecuronium. SETTINGS AND DESIGN: A prospective, randomized comparative study was done at a state-owned tertiary care teaching hospital. MATERIALS AND METHODS: After obtaining the Institutional Ethical Committee approval and written informed consent, sixty patients of either gender aged 18-60 years, the American Society of Anesthesiologists physical status Class I/II, weighing 40-70 kg, were randomly divided into two groups of thirty each. Group E received 70 µg/kg ephedrine, and Group P received 0.01 mg/kg of vecuronium 3 min before intubating dose of vecuronium. Intubation was done after getting a train of four zero. Intubation time, clinical intubation grade using Cooper's scale, and hemodynamic parameters were noted. STATISTICAL ANALYSIS USED: Chi-square test and independent t-test were done with PASW statistics 18 to analyze data. RESULTS: The mean time for intubation in ephedrine group (E) was 104 ± 23.282 s and in the priming group (P), it was 142 ± 55.671 s (P = 0.001). All patients had clinically acceptable intubating conditions, and the grades were comparable among groups (P = 0.791). Hemodynamic parameters were comparable between groups at all time frames (P > 0.05). CONCLUSION: Pretreatment with ephedrine 70 µg/kg shortens the onset time of vecuronium for intubation and is superior to the priming technique. Low-dose ephedrine, when used along with propofol induction, provides hemodynamic stability during induction and intubation.

Comparison of rocuronium at two different doses and succinylcholine for endotracheal intubation in adult patients for elective surgeries.

BACKGROUND: The effects of rocuronium at two different doses, that is, 0.6 mg/kg (2 × ED95) and 0.9 mg/kg (3 × ED95), were compared with succinylcholine (2 mg/kg) when used for endotracheal intubation in adult patients for elective surgeries under general anesthesia. MATERIALS AND METHODS: Ninety patients were divided into three groups of 30 each. Groups A, B received injection rocuronium at 0.6 mg/kg, 0.9 mg/kg respectively and Group C received succinylcholine at 2 mg/kg. Onset of action of relaxant, intubation conditions, time taken to intubate and duration of action were compared. STATISTICAL ANALYSIS USED: To compare the statistical difference in the age, weight, height of the study subjects, onset of action of relaxant, intubation conditions, time taken to intubate, and duration of action analysis of variance and unpaired t-test were used. RESULTS: The onset time was considerably shorter with rocuronium 0.9 mg/kg than 0.6 mg/kg. The onset time of rocuronium 0.9 mg/kg was found to be significantly longer than succinylcholine 2 mg/kg. Time taken to intubate was shortest with succinylcholine 2 mg/kg. The time taken to intubate with the rocuronium 0.9 mg/kg was found to be comparable to that of rocuronium 0.6 mg/kg. Intubation score of rocuronium 0.9 mg/kg was the best (17.75), which was comparable with succinylcholine. However, the intubation score obtained with rocuronium 0.6 mg/kg was inferior. Duration of action was shortest with succinylcholine. The duration of action is prolonged when the dose of rocuronium is increased from 0.6 to 0.9 mg/kg. CONCLUSION: Rapid sequence induction of anesthesia with propofol and fentanyl, succinylcholine allowed a more rapid endotracheal intubation sequence and created superior intubation conditions than rocuronium. However, the technique of using a large dose of rocuronium to achieve perfect conditions for tracheal intubation may have application whenever succinylcholine is relatively contraindicated.

A comparative study of effect of sevoflurane on intubating conditions with rocuronium in neurosurgical patients.

BACKGROUND AND AIMS: Rocuronium may not always be the preferred relaxant for rapid sequence intubation. When 2% sevoflurane is used in conjunction with rocuronium, it may reduce the time required for achieving complete skeletal muscle relaxation with the intubating dose of rocuronium. METHODS: This study was prospective, randomised, double-blind in nature and compared the effect of sevoflurane on intubation time and intubating conditions when used along with rocuronium. Thirty adult patients belonging to American Society of Anesthesiologists physical status Grades 1 and 2, of either gender aged between 30 and 65 years undergoing neurosurgical operations were randomly allocated into two equal groups: Group R received 0.8 mg/kg rocuronium, and Group RS received 0.8 mg/kg of rocuronium with 2% sevoflurane. Onset time of intubation was assessed using train-of-four stimuli. The intubating conditions were compared using the Cooper scoring system and the haemodynamic responses were compared between the two groups. RESULTS: The onset time of intubation was 101.73 ± 10.28 s in Group R and 60.4 ± 4.1 s in Group RS (P < 0.001), with excellent intubating conditions in both groups and without any adverse effects. Significant differences in heart rate and mean arterial pressure were seen immediately after intubation, at 1 and 3 min (P < 0.05) between the two groups. CONCLUSION: Rocuronium 0.8 mg/kg along with 2% sevoflurane provides excellent intubating conditions within 60-66 s from its administration.

Intubating conditions and side effects of propofol, remifentanil and sevoflurane compared with propofol, remifentanil and rocuronium: a randomised, prospective, clinical trial.

BACKGROUND: Tracheal intubation without muscle relaxants is usually performed with remifentanil and propofol or sevoflurane. Remifentanil 1.0 to 4.0 µg·kg(-1) and propofol 2.0-3.0 mg·kg(-1) or sevoflurane up to 8.0 Vol% provide acceptable, i.e. excellent or good intubating conditions. We hypothesized that sevoflurane 1.0 MAC would provide acceptable intubating conditions when combined with propofol and remifentanil. METHODS: Eighty-three patients to be intubated were randomised to two groups. The SEVO group received propofol 1.5 mg kg(-1), remifentanil 0.30 µg kg min(-1) and sevoflurane 1.0 MAC; the MR group received the same doses of propofol and remifentanil plus rocuronium 0.45 mg kg(-1). We evaluated intubation and extubation conditions, mean arterial pressure (MAP), heart rate (HR) and bispectral index (BIS). The vocal cords were examined for injury by videolaryngoscopy before and 24 hours after surgery. RESULTS: ACCEPTABLE INTUBATING CONDITIONS WERE SEEN MORE FREQUENTLY WITH ROCURONIUM THAN WITH SEVOFLURANE: 97% versus 82%; p = 0.03; the subscore for vocal cords was comparable: 100% versus 98%. MAP before intubation decreased significantly compared with the MAP at baseline to the same extent in both groups; ephedrine IV was given in 15 (SEVO) versus 16 (MR) patients; p = 0.93. BIS at tracheal intubation was 27 (13-65) in the SEVO group, 29 (14-62) in the MR group; p = 0.07. Vocal cord injuries (oedema, haematoma) were similar: 4 patients in each group. CONCLUSIONS: Overall intubating conditions were better when rocuronium was used; the subscore for vocal cords was comparable. The incidence of side effects was the same in the two groups. TRIAL REGISTRATION: ClinicalTrials.Gov: NCT 01591031.

Intubating conditions following rapid sequence induction with three doses of succinylcholine.

BACKGROUND: The aim of this prospective, randomized, double-blind study was to compare tracheal intubating conditions and the duration of apnoea following administration of 0.4, 0.6 and 1.0 mg/kg of succinylcholine during simulated rapid sequence induction of anaesthesia. METHODS: Anaesthesia was induced with fentanyl 2 µg/kg and propofol 2 mg/kg followed by application of cricoid pressure. Patients were randomly allocated to three groups according to the dose of succinylcholine administered (0.4, 0.6 or 1.0 mg/kg). Intubating conditions were assessed at 60 s after succinylcholine administration. Time to first diaphragmatic contraction (apnoea time) and time to resumption of regular spontaneous breathing were noted. RESULTS: Excellent intubating conditions were obtained in 52.4%, 95.7% and 100% of the patients after 0.4, 0.6 and 1.0 mg/kg succinylcholine, respectively; P<0.001. Acceptable intubating conditions (excellent and good grade combined) were obtained in 66.7%, 100% and 100% of the patients after 0.4, 0.6 and 1.0 mg/ kg succinylcholine, respectively; P<0.001. Apnoea time and resumption of regular spontaneous breathing were dose-dependent. Apnoea time was 3.8±1.1 min, 4.3±0.9 min and 8.2±3.4 min in groups 0.4, 0.6 and 1.0 mg/kg, respectively; P<0.001. Time to regular spontaneous breathing was 5.3±1.2 min, 5.5±1.1 min and 8.9±3.5 min in groups 0.4, 0.6 and 1.0 mg/kg, respectively; P<0.001. CONCLUSION: A dose of 0.6 mg/kg succinylcholine can be used for rapid sequence induction of anaesthesia as it provides acceptable intubating conditions with a shorter apnoea time compared with a dose of 1 mg/kg.

Comparison of intubating conditions following administration of low-dose rocuronium or succinylcholine in adults: A randomized double blind study.

CONTEXT: Though rocuronium has a rapid onset of neuromuscular blockade like succinylcholine without the latter's adverse effects, its use is limited due to its prolonged action. AIM: Aim was to evaluate whether reducing the intubating dose of rocuronium shortens its duration of action, yet provides clinically acceptable intubating conditions. SETTINGS AND DESIGN: tt was a prospective, randomized, and double blind trial. MATERIALS AND METHODS: 100 American Society of Anaesthesiologists Physical Status (ASAPS) I or II patients aged between 18-65 years scheduled for elective surgery were randomly allotted one of the four rocuronium groups (rocuronium dose of 0.3 mg/kg intubated at 60 s or at 90 s, rocuronium 0.6 mg/kg intubated at 60 s or at 90 s) orsuccinylcholine group (succinylcholine 1.0 mg/kg intubated at 60 s) and intubating conditions were assessed with: Ease of laryngoscopy, vocal cord position, and reaction to insertion of tracheal tube and cuff inflation. STATISTICAL ANALYSIS: Statistical tests used were analysis of variance (ANOVA), Chi-Square test, Repeated measures of ANOVA and Mann-Whitney U test. RESULTS: Rocuronium in dosage of 0.3 mg/kg gaveclinically acceptable intubating conditions in 35% and 60% subjects at 60 s or 90 s, respectively, whereas in dosage of 0.6 mg/kg, intubating conditions were acceptable in 80% and 100% subjects intubated at 60 s and 90 s. CONCLUSION: Rocuronium in dose of 0.3 mg/kg does not give clinically acceptable intubating conditions at 60 or 90 s but has shorter duration of action. Rocuronium in dose of 0.6 mg/kg gives clinically acceptable intubating conditions at 60 or 90 s, comparable to succinylcholine 1 mg/kg.

Comparison of intubating conditions between rocuronium with priming and without priming: Randomized and double-blind study.

BACKGROUND: Rocuronium produces faster neuromuscular blockade compared with other neuromuscular blocking drugs. It produces comparable intubating conditions to that of succinylcholine, but does not have the short intubation time of the latter. Hence, it may not be preferable for rapid sequence intubation, but rocuronium with priming may produce comparable intubating time and conditions to that of succinylcholine. Rocuronium with priming may be an alternative to succinylcholine in rapid sequence intubation in conditions where succinylcholine is contraindicated. The present study was conducted to compare the intubating conditions and intubation time of rocuronium with and without priming. METHODS: Sixty patients of ASA physical status I and II, aged between 18 and 60 years, of both sexes, were divided into priming and control groups of 30 each. Patients in the priming group received 0.06 mg/kg of rocuronium and those in the control group received normal saline. All patients received fentanyl 1 µg/kg, followed by thiopentone 5 mg/kg for induction. Intubating dose of rocuronium 0.54 mg/kg in the priming group and 0.6 mg/kg in the control group were administered 3 min after priming. Onset time of intubation was assessed using a Train of Four stimuli, and the intubating conditions were compared by the Cooper scoring system. RESULTS: The onset time of intubation was 50.67±7.39 s in the priming group and 94.00±11.62 s in the control group, with excellent intubating conditions in both the groups and without any adverse effects. CONCLUSIONS: Priming with rocuronium provides excellent intubating conditions in less than 60 s with no adverse effects.

Comparison of intubating conditions and hemodynamic responses to tracheal intubation with different effect-site concentrations of remifentanil without muscle relaxants during target-controlled infusion of propofol.

BACKGROUND: We compared the effects of different remifentanil effect-site concentrations on intubating conditions, and cardiovascular and bispectral index score (BIS) responses to intubation at a fixed effect-site concentration of propofol without muscle relaxants. METHODS: Sixty-four patients were randomly assigned to one of three groups: remifentanil 2 (group R2, n = 22), 4 (group R4, n = 21), or 6 ng/ml (group R6, n = 21). Anesthesia was induced using target-controlled infusion of propofol 5 microgram/ml and each concentration of remifentanil. Laryngoscopy and intubation was attempted at 2.5 min following induction. Intubating conditions were assessed as excellent, good or poor using a standard scoring system. Mean arterial pressure (MAP), heart rate (HR), and BIS values were assessed. RESULTS: Excellent or good intubating conditions were obtained in 91% of group R4 and 95% of R6, both of which are higher compared with 32% of R2 (P < 0.01). MAP and HR decreased significantly after induction in all groups. After intubation, they recovered to baseline value in group R2 and R4 but were significantly less than baseline values in R6. BIS response to intubation was attenuated in group R4 and R6 but not R2. Hypotension was more frequent in group R6 than R2. CONCLUSIONS: Remifentanil target concentrations of 4 or 6 ng/ml combined with 5 microgram/ml propofol provided good or excellent conditions for tracheal intubation and prevented cardiovascular and BIS response during induction without muscle relaxants. However, the use of 6 ng/ml dose was associated with frequent occurrence of hypotension and bradycardia requiring treatment.

Comparison of intubating conditions and hemodynamic responses to tracheal intubation with different effect-site concentrations of remifentanil without muscle relaxants during target-controlled infusion of propofol / 대한마취과학회지

BACKGROUND: We compared the effects of different remifentanil effect-site concentrations on intubating conditions, and cardiovascular and bispectral index score (BIS) responses to intubation at a fixed effect-site concentration of propofol without muscle relaxants. METHODS: Sixty-four patients were randomly assigned to one of three groups: remifentanil 2 (group R2, n = 22), 4 (group R4, n = 21), or 6 ng/ml (group R6, n = 21). Anesthesia was induced using target-controlled infusion of propofol 5 microgram/ml and each concentration of remifentanil. Laryngoscopy and intubation was attempted at 2.5 min following induction. Intubating conditions were assessed as excellent, good or poor using a standard scoring system. Mean arterial pressure (MAP), heart rate (HR), and BIS values were assessed. RESULTS: Excellent or good intubating conditions were obtained in 91% of group R4 and 95% of R6, both of which are higher compared with 32% of R2 (P < 0.01). MAP and HR decreased significantly after induction in all groups. After intubation, they recovered to baseline value in group R2 and R4 but were significantly less than baseline values in R6. BIS response to intubation was attenuated in group R4 and R6 but not R2. Hypotension was more frequent in group R6 than R2. CONCLUSIONS: Remifentanil target concentrations of 4 or 6 ng/ml combined with 5 microgram/ml propofol provided good or excellent conditions for tracheal intubation and prevented cardiovascular and BIS response during induction without muscle relaxants. However, the use of 6 ng/ml dose was associated with frequent occurrence of hypotension and bradycardia requiring treatment.

A Comparative Study of Different Induction Techniques (Propofol-Placebo, Propofol-Ephedrine and Propofol-Placebo-Crystalloid) on Intubating Conditions after Rocuronium Administration

This was a prospective randomized double blind controlled study to compare intubating conditions at 60 seconds with rocuronium 0.6 mg/kg by using three different induction techniques: propofol-placebo (PP), propofol-ephedrine (PE) and propofol-placebocrystalloid (PC). Ninety patients were included and randomly allocated to receive one of the three combinations. The patients were induced using fentanyl 2 μg/kg, followed by propofol 2.5 mg/kg with normal saline as placebo (Group PP and Group PC) or ephedrine 70 μg/kg (Group PE) given over 30 seconds. Subsequently, rocuronium 0.6 mg/kg was given over five seconds and endotracheal intubations were performed 60 seconds later. Intubating conditions were clinically acceptable in all patients except in four patients in PP group, who had poor intubating conditions. The proportion of excellent intubating conditions was significantly highest in Group PE (94%) followed by Group PC (81%) and lowest in Group PP (50%). In conclusion, induction with propofol-ephedrine and propofol-placebo-crystalloid combinations provided significantly better intubating conditions than propofol alone, when rocuronium 0.6 mg/kg was used for intubation at 60 seconds.