Modified anterior approach versus traditional posterior approach for ultrasound-guided superior laryngeal nerve block in awake endotracheal intubation: a randomized non-inferiority clinical trial.

STUDY OBJECTIVE: This study was undertaken to compare the effect of the modified ultrasound-guided anterior superior laryngeal nerve block (SLNB) with the traditional ultrasound-guided posterior SLNB in providing intubation conditions during awake tracheal intubation (ATI) in patients without difficult airway. DESIGN: Randomized, assessor-blind. Registration number: ChiCTR2200058086. SETTING: West China Hospital of Sichuan University, Chengdu, China. PATIENTS: 104 patients aged 18-65 years, of American Society of Anesthesiologists status I-III, posted for elective general surgery with general endotracheal anesthesia. INTERVENTIONS: The patients were randomized into two groups (modified group, n = 52; traditional group, n = 52). Modified anterior SLNB or traditional posterior SLNB was performed under ultrasound guidance. MEASUREMENTS: The primary outcome was the proportion of acceptable intubation condition (AIC), which was analyzed in both per-protocol (PP) and intention-to-treat (ITT) populations. The prespecified non-inferiority margin was -4.8%. Secondary outcomes included intubation success rate on the first attempt, hemodynamic parameters during ATI, time taken for airway anesthesia and intubation, recall of intubation, patient perception of comfort, and incidence and severity of postoperative complications. MAIN RESULTS: In the PP population, the proportion of AIC in the modified group was 49/49 (100%) and that in the traditional group was 49/49 (100%), absolute difference 0, lower limit of 1-sided 95% CI, -0.3%. In the ITT population, the primary outcomes in the modified and traditional group were 52/52 (100%) and 51/52 (98.1%), respectively, with an absolute difference of 1.9% and a lower limit of 1-sided 95% CI of -1.2%. The non-inferiority of modified ultrasound-guided anterior SLNB was confirmed in both populations. CONCLUSIONS: Among adults without difficult airways during videolaryngoscope-assisted ATI, the modified ultrasound-guided anterior SLNB, compared to the traditional posterior approach, showed a statistically non-inferior effect in terms of providing AIC.

Efficiency of face mask ventilation before and after neuromuscular blockade: A randomised, double-blind controlled study.

Background and Aims: The traditional practice of administrating neuromuscular blocking drugs (NMBDs) after checking face mask ventilation is challenged repeatedly. This study compared the efficiency of face mask ventilation before and after administrating an NMBD in a patient with a normal airway. The secondary outcome measured was the grade of mask ventilation and tracheal intubating conditions. Methods: After ethical approval, patients (n = 120) in the age group of 18-65 years scheduled for elective surgery under general anaesthesia were randomly assigned into two groups. Group 1 received an NMBD before checking face mask ventilation. Group 2 received an NMBD after checking face mask ventilation. Lungs were ventilated for 180 s, during which expiratory tidal volume (Vte) was recorded as the primary outcome. Hans's grading for face mask ventilation was used to grade mask ventilation. The ease of intubation was assessed based on intubating conditions (ease of laryngoscopy, vocal cord movement, and limb movement). SPSS 20.0 software was used for statistical analysis. Results: For a total of 180 seconds of mask ventilation, the mean (standard deviation) Vte measured after apnoea was significantly higher in Group 1 versus Group 2 [471.9 (63.3) vs 434.8 (77.0) mL/breath, P = 0.004]. The intubating condition was either excellent or good in all patients. Conclusion: The administration of NMBDs resulted in a larger mask Vte and shorter intubation time.

Sevoflurane at 1.0 MAC together with remifentanil and propofol produces clinically acceptable intubation conditions at the vocal cords: A prospective randomized study.

Objective The overall intubation conditions after tracheal intubation with remifentanil, propofol, and sevoflurane at 1.0 minimum alveolar concentration (MAC) are worse than with rocuronium at 0.45 mg/kg. Therefore, we compared the intubation conditions and laryngeal morbidity (vocal cord injuries, hoarseness, and sore throat) with sevoflurane at 1.2 and 1.4 MAC versus 1.0 MAC. Methods In this prospective clinical trial, 90 patients were randomized to 3 groups: the sevoflurane 1.0, 1.2, and 1.4 MAC groups. At 3 min, tracheal intubation was performed and the patients' intubation conditions were assessed. The vocal cords were examined for injury by videolaryngoscopy. Additionally, the incidence and severity of laryngeal morbidity were compared between women and men. Results Acceptable intubation conditions were seen in 72% of the patients without significant differences between the groups. Overall, vocal cord injuries (oedema) occurred in three (4%) patients. Women reported sore throat more often than men (51% vs. 21%, respectively). Conclusions Intubation conditions were not improved with higher sevoflurane concentrations. The incidence and severity of sore throat were greater in women than men. TRIAL REGISTRATION: ClinicalTrials.Gov: NCT 01896245.

DOSE RESPONSE RELATIONSHIP OF NEUROMUSCULAR BLOCKADE, INTUBATION CONDITIONS AND CARDIOVASCULAR CHANGES WITH CHANDONIUM IODIDE.

One hundred and forty ASA physical status I and II patients undergoing general or gynaecological surgery were the subjects of this study. Patients were randomly assigned into five groups receiving 100, 150, 180, 200 and 250 µg/kg I.V. of chandonium iodide after induction of general anaesthesia with thiopentone. Neuromuscular blockade was assessed clinically, as well as, with twitch response/train of four using myotest nerve stimulator. Increasing dosage of chandonium iodide decreased the time to onset of jaw relaxation and apnoea (p<0.01) and caused linear increase in the duration of neuromuscular blockade from 10.90 ± 5.31 to 25.18 ± 7.15 min (p<0.01) over the dosage rage of 100 to 250 µg/kg. Intubation conditions also improved with increasing doses of chandonium iodide, so that, although intubation was possible in all the patients, grading of good intubation conditions were achieved in 64, 80, 88, 100 and 100% of patients in groups I to V respectively. 200 µg/kg of chandonium iodide produced ideal intubation conditions. Recovery to spontaneous ventilation was rapid and smooth, further facilitated with neuromuscular antagonists. Short lasting increase in heart rate and blood pressure was seen which was neither dose dependent nor outlasting the duration of neuromuscular blockade.

NEUROMUSCULAR BLOCKADE AND INTUBATION CONDITIONS OF THE SINGLE BOLUS DOSE (2xED90) OF ROCURONIUM BROMIDE.

Rocuronium bromide (2xED90), a new non depolarising neuromuscular blocking drug with rapid onset, intermediate duration of action and cardiostability was studied in open randomised trial in 30 patients. Neuromuscular block was monitored using a Train of Four stimulus by stimulator electrodes placed on the ulnar never close to the wrist. Intubation conditions were assessed subjectively by scoring the jaw relaxation, vocal cord and the response to intubation with same technique of anaesthesia. Clinical recovery (Dur25) of neuromuscular blockade was monitored. Haemodynamic changes were recorded. Intubation conditions were clinically acceptable in 99.6% of patients, (excellent 73%; good 26.6%) at 90s. Time to onset (Lag time) of neuromuscular block was 22.5 ± 12.6 sec and average time for the onset of block (maximum effect) was 90.9 ±10.6 sec. The duration of clinical muscular relaxation (25% recovery of twitch height) was 22.4 ± 8.30 min. Stability of cardiocirculatory system was seen.

Comparing the effects of three different additional doses of propofol infusion on intubation condition and hemodynamic changes during general anesthesia under elective surgery: A randomized, placebo-controlled, double blind clinical trial.

BACKGROUND: Laryngoscopy and endotracheal intubation can induce unfavorable hemodynamic changes as propofol itself can induce hypotension. The aim of this study was to compare the effects of three different additional doses of propofol infusion on intubation conditions and hemodynamic changes occurred after intubation. MATERIALS AND METHODS: This double-blinded prospective study was performed on 140 patients aged 18-60 who received different additional doses of propofol and were randomly allocated into 4 groups as follows: A: Received additional dose of propofol 0.5 mg/kg infused after an initial dose 1.5 mg/kg. B: Received additional dose of propofol 1 mg/kg infused after an initial dose 1 mg/kg. C: Received additional dose of propofol 1.5 mg/kg after an initial dose 1 mg/kg. D: Received propofol 2 mg/kg as a bolus with no additional dose. RESULTS: Intubation conditions were acceptable in 91.4% of Group A patients, 94.2% of Group B patients, 97.1% of Group C patients and 68.5% of Group D patients. There were no significant differences in the mean of heart rate between four groups at any time before and after laryngoscopy. Mean arterial pressure (MAP) 3 min after laryngoscopy was significantly lower in Group D versus Group A (P = 0.015) while MAP was not different at any time between other groups. CONCLUSION: Infusion of propofol 1.5 mg/kg added to initial bolus dose of propofol 1 mg/kg improves intubation conditions significantly without inducing hemodynamic changes.

Optimal dose of succinylcholine for tracheal intubation in patients during inhalation induction with sevoflurane: a randomized controlled trial.

STUDY OBJECTIVE: To determine the dose of succinylcholine during inhalation induction of a patient. DESIGNED: Prospective, double-blind, randomized study. SETTING: Operating room of a university hospital. PATIENTS: 180 adult, ASA physical status 1 and 2 patients with a suspected difficult airway, who were scheduled for surgery. INTERVENTIONS: Nonpremedicated patients were anesthetized with inhalation of 8% sevoflurane, followed by succinylcholine. Group 1 received intravenous (IV) succinylcholine 0.3 mg/kg, Group 2 had IV succinylcholine 0.6 mg/kg, and Group 3 was given IV succinylcholine 1.0 mg/kg. Direct laryngoscopy and tracheal intubation were performed after onset of succinylcholine. MEASUREMENTS: Intubation conditions were scored as excellent, good, or poor. The recovery time of spontaneous respiration, end-tidal carbon dioxide partial pressure (PETCO2), and pulse oxygen saturation (SpO2) were recorded. MAIN RESULTS: Acceptable conditions (excellent and good) for intubation were rated in 80% of Group 1 patients (0.3 mg/kg succhinylcholine), 91.7% of Group 2 patients (0.6 mg/kg), and 93.3% of Group 3 patients (1.0 mg/kg), respectively. Intubation scores were similar in Groups 2 and 3, and were significantly higher than in Group 1 patients (0.3 mg; P < 0.01). Time to recovery of spontaneous respiration in Group 3 was significantly prolonged compared with Groups 1 and 2 (238 ± 59 sec vs 132 ± 43 sec, P < 0.001; 238 ± 59 sec vs 151 ± 47 sec, P < 0.001, respectively). SpO2 in Group 3 did not differ significantly from Group 1 and 2 values. However, PETCO2 in Group 3 was significantly higher than in Groups 1 or 2. CONCLUSIONS: Succinylcholine at a dose of 0.6 mg/kg IV provided intubation conditions similar to succinylcholine at 1.0 mg/kg IV, and recovery of spontaneous respiration following a 0.6 mg/kg dose of succinylcholine was significantly shorter.