Sayuri Matsunami

Comparison of McGRATH MAC and Macintosh laryngoscopes for double-lumen endotracheal tube intubation by anesthesia residents: a prospective randomized clinical trial.

STUDY OBJECTIVE This study aimed to compare the utility of McGRATH MAC (McG) and Macintosh (McL) laryngoscopes for double-lumen endotracheal tube intubation in patients undergoing elective surgery. DESIGN Randomized clinical trial. SETTING Operating room. PATIENTS Fifty adult patients scheduled for elective surgery under 1-lung ventilation with American Society of Anesthesiologists physical status 1 to 3. INTERVENTIONS Double-lumen endotracheal tube intubation was performed with the McG (McG group; 25 patients) or conventional McL (McL group; 25 patients) laryngoscope by anesthesia residents. MEASUREMENTS The number of attempts to successful intubation, intubation time, percentage of glottis opening score, and subjective difficulty of laryngoscopy and tube passage through the glottis were assessed. MAIN RESULTS The total numbers of intubation attempts were 1 (McG group, 24 patients; McL group, 16 patients), 2 (McG group, 1 patient; McL group, 8 patients), and 3 (McG group, 0 patient; McL group, 1 patient), with significant differences between the two groups (P = .018). Intubation time was significantly shorter in the McG group compared with the McL group (McG: 17.1 ± 4.6 seconds vs McL: 20.8 ± 5.9 seconds, P = .026). The percentage of glottis opening score was significantly higher in the McG group compared with the McL group (McG: 88.4% ± 13.7% vs McL: 71.4% ± 20.4%, P = .004). CONCLUSIONS The McG demonstrated a better intubation profile compared with the McL, possibly due to its ease of use for double-lumen endotracheal tube intubation. Clinical Trial registry number: UMIN000014636.

Comparison of Direct and Indirect Laryngoscopes in Vomitus and Hematemesis Settings: A Randomized Simulation Trial.

Background. Videolaryngoscopes may not be useful in the presence of hematemesis or vomitus. We compared the utility of the Macintosh laryngoscope (McL), which is a direct laryngoscope, with that of the Pentax-AWS Airwayscope (AWS) and McGRATH MAC (McGRATH), which are videolaryngoscopes, in simulated hematemesis and vomitus settings. Methods. Seventeen anesthesiologists with more than 1 year of experience performed tracheal intubation on an adult manikin using McL, AWS, and McGRATH under normal, hematemesis, and vomitus simulations. Results. In the normal setting, the intubation success rate was 100% for all three laryngoscopes. In the hematemesis settings, the intubation success rate differed significantly among the three laryngoscopes (P = 0.021). In the vomitus settings, all participants succeeded in tracheal intubation with McL or McGRATH, while five failed in the AWS trial with significant difference (P = 0.003). The intubation time did not significantly differ in normal settings, while it was significantly longer in the AWS trial compared to McL or McGRATH trial in the hematemesis or vomitus settings (P < 0.001, compared to McL or McGRATH in both settings). Conclusion. The performance of McGRATH and McL can be superior to that of AWS for tracheal intubation in vomitus and hematemesis settings in adults.

Comparison of Pentax-AWS Airwayscope and Glidescope for Infant Tracheal Intubation by Anesthesiologists during Cardiopulmonary Arrest Simulation: A Randomized Crossover Trial

Background. Recent guidelines for infant cardiopulmonary resuscitation emphasize that all rescuers should minimize interruption of chest compressions, even for endotracheal intubation. We compared the utility of the Pentax-AWS Airwayscope (AWS) with the Glidescope (GS) during chest compressions on an infant manikin. Methods. Twenty-four anesthesiologists with more than two years of experience performed tracheal intubation on an infant manikin using the AWS and GS, with or without chest compressions. Results. In GS trials, none of the participants failed without compressions, while three failed with compressions. In AWS trials, all participants succeeded regardless of chest compressions. Intubation time was significantly longer with chest compressions with the GS (P < 0.05), but not with the AWS. Difficulty of operation on a visual analog scale (VAS) for laryngoscopy did not increase significantly with chest compressions with either the GS or the AWS, while the VAS for tube passage through the glottis increased with compressions with the GS, but not with the AWS. Conclusion. We conclude that in infant simulations managed by anesthesiologists, the AWS performed better than the GS for endotracheal intubation with chest compressions.

Utility of a Gum-Elastic Bougie for Difficult Airway Management in Infants: A Simulation-Based Crossover Analysis

Background. Direct laryngoscopy with the Miller laryngoscope (Mil) for infant tracheal intubation is often difficult to use even for skilled professionals. We performed a simulation trial evaluating the utility of a tracheal tube introducer (gum-elastic bougie (GEB)) in a simulated, difficult infant airway model. Methods. Fifteen anesthesiologists performed tracheal intubation on an infant manikin at three different degrees of difficulty (normal [Cormack-Lehane grades (Cormack) 1-2], cervical stabilization [Cormack 2-3], and anteflexion [Cormack 3-4]) with or without a GEB, intubation success rate, and intubation time. Results. In the normal and cervical stabilization trials, all intubation attempts were successful regardless of whether or not the GEB was used. In contrast, only one participant succeeded in tracheal intubation without the GEB in the anteflexion trial; the success rate significantly improved with the GEB (P = 0.005). Intubation time did not significantly change under the normal trial with or without the GEB (without, 12.7 ± 3.8 seconds; with, 13.4 ± 3.6 seconds) but was significantly shorter in the cervical stabilization and anteflexion trials with the GEB. Conclusion. GEB use shortened the intubation time and improved the success rate of difficult infant tracheal intubation by anesthesiologists in simulations.

The effect of extraction angle on endotracheal tube extubation force: Simulation and randomized clinical trial

Objective To evaluate the extraction force generated at different extubation angles using a manikin simulation and a randomized clinical trial. Methods Simulations were performed on a manikin to assess the force generated at extubation angles of 0°, 30°, 45°, 60°, 90° and 120° relative to the ground. The trial compared extraction force and changes in vital signs in patients undergoing general anaesthesia with tracheal intubation followed by extubation at 60° or 90°. Results The simulation study found that the extubation force was significantly lower at 45° and 60° than at all other extraction angles. In the trial, extubation at 60° resulted in significantly lower extraction force and systolic blood pressure elevation (n = 23) than extubation at 90° (n = 23). Conclusion Findings in a manikin simulation were confirmed by those of a randomized clinical trial, where extubation at 60° required less force than 90°, and was accompanied by less SBP elevation. Extubation at 60° is less invasive than extubation at 90°.

Application of a modified intubating laryngeal mask for pediatric lung biopsies.

A 9-year-old girl (height, 127 cm; and weight, 27 kg) with interstitial pneumonia associated with graft versus host disease after bone marrow transplantation was scheduled for a lung biopsy. We first considered intubation with a tracheal tube having an internal diameter of 6.0mm for airwaymanagement. However, because the outer diameter of the bronchofiberscope was 4.9 mm and difficulties were anticipated with ventilation and handling of the bronchofiberscope during the procedure, we decided to use the air-Q laryngeal mask with a shortened shaft (the shaft was cut by ~3 cm) (Figure). Fentanyl and propofol were administered by target-controlled infusion. Rocronium was administered after confirming sufficient ventilation. A size 2.5 air-Q was then inserted, and sufficient sealing pressure confirmed. The procedure was performed uneventfully through the inner lumen of the air-Q while maintaining sufficient mechanical ventilation via the attached connecter. She was extubated in the operation room with no pharyngeal pain or hoarseness.

Air-Q intubating supraglottic device for tracheal tumor resection

[1] Sun DA, Warriner CB, Parsons DG, Klein R, Umedaly HS, Moult M. The GlideScope Video Laryngoscope: randomized clinical trial in 200 patients. Br J Anaesth 2005;94:381-4. [2] Cavus E, Neuman T, Doerges V, Moeller T, Scharf E, Wagner K, et al. First clinical evaluation of the C-MAC D-Blade videolarngoscope during routine and difficult intubation. Anesth Analg 2011;112:382-5. [3] Aziz M, Brambrink A. The Storz C-MAC video laryngoscope: description of a new device, case report, and brief case series. J Clin Anesth 2011;23:149-52.

Worst-case scenario intubation of laryngeal granuloma: a case report

BackgroundIntubation of patients with laryngeal granulomas on the vocal folds are sometimes difficult to manage because of potential airway obstruction. Laryngeal granulomas usually have flexible stalks where they attach to the vocal folds. We report a worst-case scenario of dislocation of the laryngeal granuloma during induction of anaesthesia.Case presentationWe present a case of laryngeal granulomas on the posterior vocal fold. A 20-year-old woman had an approximately 10-mm tumour in the laryngeal arytenoid region. Manual ventilation resulted in the tumour lodging in the subglottis and the inflated cuff of the intubation tube successfully returned it to its original position during tube withdrawal. Images were obtained using an Airway Scope® (Hoya-Pentax, Tokyo, Japan) and a video laryngoscope.ConclusionIn our case, the tumour was benign and relatively small in size; therefore, we did not select tracheotomy as an airway management strategy. The case had a granulomatous tumour arising from the posterior vocal folds on the right side, and the tumour was very flexible. To promptly gain control of the airway in such a case using direct laryngoscopy, thus avoiding tracheotomy, other strategies are suggested, such as bronchoscopic visualization with awake or semi-awake intubation.

Head elevation and lateral head rotation effect on facemask ventilation efficiency: Randomized crossover trials

Purpose: We performed two prospective randomized crossover trials to evaluate the effect of head elevation or lateral head rotation to facemask ventilation volume. Methods: In the first trial, facemask ventilation was performed with a 12‐cm high pillow (HP) and 4‐cm low pillow (LP) in 20 female patients who were scheduled to undergo general anesthesia. In the second trial, facemask ventilation was performed with and without lateral head rotation in another 20 female patients. Ventilation volume was measured in a pressure‐controlled ventilation (PCV) manner at 10, 15, and 20 cmH2O inspiratory pressures. Results: In the first trial evaluating head elevation effect, facemask ventilation volume was significantly higher with a HP than with a LP at 15 and 20 cmH2O inspiratory pressure (15 cmH2O: HP median540 [IQR480–605] mL, LP 460 [400–520] mL, P = 0.006, 20 cmH2O: HP 705 [650–800] mL, LP 560 [520–677] mL, P < 0.001). In the second trial, lateral head rotation did not significantly increase facemask ventilation volume at all inspiratory pressure. Conclusion: Head elevation increased facemask ventilation volume in normal airway patients, while lateral head rotation did not.

Unexpected Collection of Pulmonary Venous Blood from a Pulmonary Artery Catheter: A Case Report

Background Pressure and waveform at the catheter tip are continuously monitored during catheterization of pulmonary artery to ensure accurate catheter placement. We present a case in which pulmonary venous blood was unexpectedly collected from the pulmonary artery catheter despite pulmonary artery pressure and waveform detection at the catheter tip, and describe the measures taken to correct the catheter placement. Case Presentation A 74-year-old male underwent mitral valve plasty for cardiac failure caused by mitral valve regurgitation. Preoperative transthoracic echocardiography showed no septal shunt. The pulmonary artery was catheterized through a sheath introducer in the right jugular vein, and the balloon was inflated after insertion of a 15-cm catheter. The catheter was advanced until a pulmonary artery waveform was detected and the pulmonary artery wedge pressure was 21 mmHg at end-expiration. The balloon was deflated and the catheter tip was pulled back 3 cm. Pulmonary artery waveforms and appropriate a and v waves were detected, and transesophageal echocardiography confirmed the location of the catheter tip in the right pulmonary artery. The first collected blood sample had an oxygen partial pressure of 358.8 mmHg, carbon dioxide partial pressure of 20.1 mmHg, and oxygen saturation of 99%, indicating pulmonary venous blood. The pulmonary artery catheter was pulled back 5 cm, but a second blood sample showed the same results. The catheter was pulled back a further 6 cm while the location of the catheter tip was monitored on X-ray fluoroscopy. Blood gas testing through the catheter tip showed oxygen saturation of 84.4 % and oxygen partial pressure of 41.6 mmHg. Surgery was performed uneventfully. Postoperative chest radiographs showed proper placement of the pulmonary artery catheter, but radiographs on postoperative day 1 showed over-insertion, although the insertion length was unchanged. The catheter was removed. The patient was discharged 2 months postoperatively. Conclusions Our case highlights the fact that the tip of the pulmonary artery catheter can easily advance into a peripheral branch of the pulmonary artery and cause pulmonary venous blood to be sampled instead of pulmonary arterial blood. A variety of monitoring techniques are needed to confirm accurate catheter placement.