Comparison of Pentax Airway Scope and Macintosh laryngoscope for orotracheal intubation in children: A randomised non-inferiority trial.

BACKGROUND: Pentax Airway Scope (AWS) is a recently developed videolaryngoscope for use in both normal and difficult airways, yet its use in paediatric patients has not been established. The purpose of this study was to evaluate the efficacy of the Pentax AWS regarding intubation time, laryngeal view and ease of intubation in paediatric patients with normal airway, compared to Macintosh laryngoscope. METHOD: A total of 136 paediatric patients aged 1-10 with American Society of Anaesthesiologists physical status I or II undergoing general anaesthesia were randomly allocated into two groups: Macintosh laryngoscope (n = 68) and Pentax Airway Scope (n = 68). Primary outcome was intubation time. Cormack-Lehane laryngeal view grade, application of optimal laryngeal external manipulation, intubation difficulty scale, intubation failure rate and adverse events were also measured. RESULT: No significant difference was observed between the two groups regarding intubation time (P = 0.713). As for the laryngeal view grade, the Pentax group resulted in lower graded cases compared to the Macintosh group (P = 0.000). No optimal laryngeal external manipulation application was required in the Pentax group. Intubation difficulty scale resulted in lower values for Pentax group (P = 0.001). Failure rate was not different between the two groups (P = 0.619). There were significantly more teeth injury cases in the Pentax group than Macintosh group (P = 0.042). CONCLUSION: Pentax Airway Scope provided similar intubation time and success rate, while improving laryngeal view, compared to Macintosh laryngoscopy in children with normal airway. When using Pentax AWS in children, however, the risk of teeth injury may increase.

McGrath Video Laryngoscopy Facilitates Routine Nasotracheal Intubation in Patients Undergoing Oral and Maxillofacial Surgery: A Comparison With Macintosh Laryngoscopy.

PURPOSE: The McGrath video laryngoscope (VL) offers excellent laryngoscopic views and increases the success rate of orotracheal intubation in patients with normal and difficult airways. The purpose of this randomized controlled trial was to compare the McGrath VL with the Macintosh laryngoscope to investigate the efficacy of the McGrath VL for routine nasotracheal intubation in patients with an expected normal airway. MATERIALS AND METHODS: To address the research purpose, the efficacy of the McGrath VL for routine nasotracheal intubation was compared with that of the Macintosh laryngoscope. The predictor variable was the laryngoscopic technique (McGrath VL vs Macintosh laryngoscope). The outcome variables were the time to successful intubation, laryngoscopic views before and after optimal external laryngeal manipulation (OELM), use of Magill forceps, ease of intubation, and severity of oropharyngeal bleeding. RESULTS: Data from 35 patients undergoing oral and maxillofacial surgery were assessed. The time to intubation was 10.5 seconds shorter in the McGrath group than in the Macintosh group (34.4 ± 13.7 vs 44.9 ± 15.6 seconds; P = .004). The incidence of grade 1 glottic view before OELM was higher in the McGrath group than in the Macintosh group (83 vs 57%; P = .019). The frequency of Magill forceps use was lower in the McGrath group than in the Macintosh group (6 vs 34%; P = .003). CONCLUSION: McGrath VL facilitates routine nasotracheal intubation in expected normal airways by providing a shorter intubation time and better laryngoscopic views compared with the Macintosh laryngoscope.

Effect of High-Flow Nasal Oxygenation on Gastric Insufflation in Patients Undergoing Laryngeal Microsurgery under Tubeless General Anesthesia with Neuromuscular Blockade.

BACKGROUND: High-flow nasal oxygenation is an oxygen delivery method by which high concentrations of heated humidified oxygen are supplied via the nasal cavity. This study aimed to investigate the effect of high-flow nasal oxygenation on gastric volume change in adult patients undergoing laryngeal microsurgery under tubeless general anesthesia with neuromuscular blockade. METHODS: Patients aged 19-80 years with an American Society of Anesthesiologists physical status 1 or 2 who were scheduled to undergo laryngoscopic surgery under general anesthesia were recruited. Patients received high-flow nasal oxygenation therapy at 70 L/min during surgery under general anesthesia with neuromuscular blockade. The cross-sectional area of the gastric antrum was measured via ultrasound in the right lateral position before and after high-flow nasal oxygenation, and the gastric volume was calculated. The duration of apnea, i.e., the duration of administration of high-flow nasal oxygenation in the paralyzed state, was also recorded. RESULTS: Of the 45 patients enrolled, 44 completed the study. There were no significant differences in the antral cross-sectional area in the right lateral position, gastric volume, and gastric volume per kg between before and after high-flow nasal oxygenation application. The median duration of apnea was 15 (interquartile range, 14-22) min. CONCLUSION: High-flow nasal oxygenation at 70 L/min during apnea with the mouth open did not influence the gastric volume in patients undergoing laryngeal microsurgery under tubeless general anesthesia with neuromuscular blockade.

Comparison of McGrath, Pentax, and Macintosh laryngoscope in normal and cervical immobilized manikin by novices: a randomized crossover trial.

BACKGROUND: The aim of this study was to compare tracheal intubation performance regarding the time to intubation, glottic view, difficulty, and dental click, by novices using McGrath videolaryngoscope (VL), Pentax Airway Scope (AWS) and Macintosh laryngoscope in normal and cervical immobilized manikin models. METHODS: Thirty-five anesthesia nurses without previous intubation experience were recruited. Participants performed endotracheal intubation in a manikin model at two simulated neck positions (normal and fixed neck via cervical immobilization), using three different devices three times each. Performance parameters included intubation time, success rate of intubation, Cormack Lehane laryngoscope grading, dental click, and subjective difficulty score. RESULTS: Intubation time and success rate during first attempt were not significantly different between the 3 groups in normal airway manikin. In the cervical immobilized manikin, the intubation time was shorter (p = 0.012), and the success rate with the first attempt was significantly higher (p < 0.001) when using McGrath VL and Pentax AWS compared with Macintosh laryngoscope. Both VLs showed less difficulty score (p < 0.001) and more Cormack Lehane grade I (p < 0.001) in both scenarios. The incidence of dental clicks was higher with Macintosh laryngoscope compared with McGrath VL in cervical immobilized airway (p < 0.001). CONCLUSIONS: McGrath VL and Pentax AWS did not show clinically significant decrease in intubation time, however, they achieved higher first attempt success rate, easier intubation and better glottis view compared with Macintosh laryngoscope by novices in a cervical immobilized manikin model. McGrath VL may reduce the risk of dental injury compared with Macintosh laryngoscope in cervical immobilized scenario. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03161730), May 22, 2017 https://clinicaltrials.gov/ct2/hom.

CONSORT the effect of intraoperative dexmedetomidine on hemodynamic responses during emergence from nasotracheal intubation after oral surgery.

BACKGROUND: Dexmedetomidine provides smooth emergence with reduced agitation. The authors hypothesized low-dose dexmedetomidine infusion might contribute to hemodynamic stability during and after nasotracheal tube extubation. METHODS: Ninety-three adult patients scheduled for oral and maxillofacial surgery were enrolled in this prospective study. Patients were randomly assigned to receive normal saline (control group, n = 31), dexmedetomidine at 0.2 µg/kg/h (DEX0.2 group, n = 31), or dexmedetomidine at 0.4 µg/kg/h (DEX0.4 group, n = 31). Mean arterial pressure (MAP), heart rate (HR), and response entropy (RE) and state entropy (SE) were recorded during emergence from anesthesia. RESULTS: Extubation times were similar in the 3 groups. Mean MAP was significantly lower at eye opening (T3) and immediately after extubation (T4) in the DEX0.2 (P = .013 and .003, respectively) and DEX0.4 group (P = .003 and .027, respectively) than in the control group. At T3 and T4, mean HR was significantly higher in the control group than in the DEX0.2 (P = .014 and .022, respectively) or DEX0.4 groups (P = .003 and <.001, respectively). In the postanesthetic care unit, mean MAP and HR were significantly lower in the DEX0.2 (P = .03 and .022, respectively) and DEX0.4 groups (P = .027 and <.001, respectively) than in the control group. CONCLUSION: Intraoperative dexmedetomidine infusion at rates of 0.2 or 0.4 µg/kg/h during oral and maxillofacial surgery could provide stable hemodynamic profiles during anesthetic emergence from nasotracheal intubation without delaying extubation times.

Effect of sex differences in remifentanil requirements for the insertion of a laryngeal mask airway during propofol anesthesia: A prospective randomized trial.

BACKGROUND: Remifentanil can improve insertion of a laryngeal mask airway (LMA) during induction with propofol. Recently, it has been suggested that there is a sex difference in opioid requirements for this procedure. The purposes of this study were to determine the effective effect-site concentration (Ce) of remifentanil for the facilitation of LMA insertion in male and female patients during propofol anesthesia without neuromuscular blockade and to evaluate whether there are sex differences in the Ce of remifentanil required for successful LMA insertion. METHODS: Forty-eight patients (24 male, 24 female) with American Society of Anesthesiologists physical status 1 or 2, aged 20 to 60 years, scheduled for minor orthopedic surgery under general anesthesia were enrolled. Anesthesia was induced by target-controlled infusion (TCI) of propofol and remifentanil. The target Ce of propofol was 5 µg/mL initially and was reduced to 3.5 µg/mL after loss of consciousness. The Ce of remifentanil given to each patient was determined by the response of the previously tested patient using 0.5 ng/mL as a step size. The 1st patient was tested at a Ce of 3.0 ng/mL of remifentanil. Successful LMA insertion was defined as smooth insertion without patient movement or significant resistance to mouth opening. RESULTS: The effective Ce of remifentanil required for successful LMA insertion on 50% of occasions (effective effect-site concentration for 50% [EC50]) as estimated by Dixon method was significantly lower in women (2.18 ±â€Š0.35 ng/mL) than in men (2.82 ±â€Š0.53 ng/mL) (P = 0.02). Using the isotonic regression method, the effective Ce of remifentanil required for successful LMA insertion on 95% of occasions (EC95) (95% confidence interval [CI]) was significantly lower in women (3.38 [3.0-3.48] ng/mL) than in men (3.94 [3.80-3.98] ng/mL). CONCLUSION: The Ce of remifentanil required to facilitate successful LMA insertion is higher during propofol induction by TCI in men than in women. When using remifentanil for LMA insertion, patient sex should be taken into account for appropriate dosing.

Predicted EC50 and EC95 of Remifentanil for Smooth Removal of a Laryngeal Mask Airway Under Propofol Anesthesia.

PURPOSE: The purpose of this study was to determine the effect-site concentration (Ce) of remifentanil in 50% of patients (EC50) and 95% of patients (EC95) for smooth laryngeal mask airway (LMA) removal in adults under propofol and remifentanil anesthesia. MATERIALS AND METHODS: Twenty-five patients of ASA physical status I-II and ages 18-60 years who were to undergo minor gynecological or orthopedic surgery were assessed in this study. Anesthesia was induced and maintained with propofol and remifentanil target-controlled infusion (TCI). Remifentanil was maintained at a predetermined Ce during the emergence period. The modified Dixon's up-and-down method was used to determine the remifentanil concentration, starting from 1.0 ng/mL (step size of 0.2 ng/mL). Successful removal of the LMA was regarded as absence of coughing/gagging, clenched teeth, gross purposeful movements, breath holding, laryngospasm, or desaturation to SpO2<90%. RESULTS: The mean±SD Ce of remifentanil for smooth LMA removal after propofol anesthesia was 0.83±0.16 ng/mL. Using isotonic regression with a bootstrapping approach, the estimated EC50 and EC95 of remifentanil Ce were 0.91 ng/mL [95% confidence interval (CI), 0.77-1.07 ng/mL] and 1.35 ng/mL (95% CI, 1.16-1.38 ng/mL), respectively. CONCLUSION: Our results showed that remifentanil TCI at an established Ce is a reliable technique for achieving safe and smooth emergence without coughing, laryngospasm, or other airway reflexes.

Anesthetic management of a patient with pulmonary arteriovenous malformation under total intravenous anesthesia : A case report.

A 23-year-old woman with pulmonary arteriovenous malformation was scheduled for open reduction and internal fixation due to her mandible fracture. Total intravenous anesthesia using propofol and remifentanil was selected as the anesthetic method in order to avoid the inhibition of hypoxic pulmonary vasoconstriction and the exacerbation of intrapulmonary shunting. After the standard monitoring devices were applied, anesthesia was then induced and maintained with a target controlled infusion of propofol and remifentanil in the range of 2.5-3.0 microg/ml and 2-3 ng/ml, respectively. Anesthesia was performed uneventfully and the patient was discharged without complication.