Heinz R. Bruppacher

The effects of common airway maneuvers on airway pressure and flow in children undergoing adenoidectomies.

Obstruction of the upper airway occurs frequently in anesthetized, spontaneously breathing children, especially in those with adenoidal hyperplasia. To improve airway patency, maneuvers such as chin lift (CL), jaw thrust (JT), and continuous positive airway pressure (CPAP) are often used. In this study, we examined the comparative efficacy of these maneuvers in children scheduled to undergo adenoidectomy. Sixteen children aged 2–9 yr were anesthetized with sevoflurane. During spontaneous breathing, the flows and pressures in the mask (ma), oropharynx (op), and esophagus (es) were measured simultaneously, and maximal pressure differences during inspiration (&Dgr;P) were calculated. After baseline recording, CL and JT maneuvers were performed in random order without and with CPAP (5 cm H2O). The observed &Dgr;Pma − Pes of 12.3 ± 3.4 cm H2O at baseline decreased with all airway maneuvers (P < 0.05). This resulted from decreases of &Dgr;Pma − Pop (P < 0.05) and &Dgr;Pop − Pes (P < 0.05) in all interventions except CL, in which &Dgr;Pma − Pop remained similar. In contrast, significant improvements of minute ventilation and maximal inspiratory peak flow (P > 0.05) were observed only with JT (with and without CPAP). We conclude that CL may improve airway patency and ventilation, whereas JT with or without CPAP was the most effective maneuver to overcome airway obstruction in children with adenoidal hyperplasia.

High-fidelity simulation demonstrates the influence of anesthesiologists' age and years from residency on emergency cricothyroidotomy skills.

BACKGROUND:Age-related deterioration in both cognitive function and the capacity to control fine motor movements has been demonstrated in numerous studies. However, this decline has not been described with respect to complex clinical anesthesia skills. Cricothyroidotomy is an example of a complex, lifesaving procedure that requires competency in the domains of both cognitive processing and fine motor control. Proficiency in this skill is vital to minimize time to reestablish oxygenation during a “cannot intubate, cannot ventilate” scenario. In this prospective, controlled, single-blinded study, we tested the hypothesis that age affects the learning and performance of emergency percutaneous cricothyroidotomy in a high-fidelity simulated cannot intubate/cannot ventilate scenario. METHODS:Thirty-six staff anesthesiologists (19 aged younger than 45 years and 17 older than 45 years) managed a high-fidelity cannot intubate/cannot ventilate scenario in a high-fidelity simulator before and after a 1-hour standardized training session. The group division cutoff age of 45 years was based on the median age of our sample subject population before enrollment. The scenarios required the insertion of an emergency percutaneous cricothyroidotomy. We compared cricothyroidotomy skills in the older group with those in the younger group using procedural time, 5-point task-specific checklist score, and global rating scale score. Correlation based on age, years from residency, weekly clinical hours worked, previous continuing medical education in airway management, and previous simulation experience was also performed. RESULTS:In both prestandardization and poststandardization, age and years from residency correlated with procedural time, checklist scores, and global rating scores. Baseline, prestandardization variables were all better for the younger group, with a mean age of 37 years, compared with the older group, with a mean age of 58 years. Procedural time was 100 (72–128) seconds versus 152 (120–261) seconds. Checklist scores were 7.0 (6.1–8.0) versus 6.0 (4.8–8.0). Global rating scale scores were 22.0 (17.8–29.8) versus 17.5 (10.4–20.6). After the 1-hour standardized training session, the younger group continued to perform better than the older group with procedural time of 75 (66–91) seconds versus 87 (78–123) seconds, checklist scores of 10.0 (9.1–10.0) versus 9.0 (8.0–10.0), and global rating scale scores of 35.0 (32.1–35.0) versus 32.0 (29.0–33.8). Regression analysis was performed on the poststandardization data. Both age and years from residency independently affected procedural time, checklist scores, and global rating scale scores (all P < 0.05). CONCLUSIONS:Baseline proficiency with simulated emergency cricothyroidotomy is associated with age and years from residency. Despite standardized training, operator age and years from residency were associated with decreased proficiency. Further research should explore the potential of using age and years from residency as factors for implementing periodic continuing medical education.

In reply: Assessing flexible bronchoscopic intubation through the AuraGain™ laryngeal mask versus a slit Guedel tube

To the Editor, We thank Liu et al. for initiating an important discussion regarding the methodology described in our article. We appreciate the opportunity to elaborate on the reasoning for using our methodology. Supraglottic airway (SGA) devices of the newest generation, such as the AuraGain (Ambu A/S; Ballerup, Denmark), allow suction of gastric contents as well as intubation. In our article, we aimed to show that intubation through the AuraGain could be achieved as rapidly and simply as with a slit Guedel device (Johnson & Johnson; Sezanne, France), which is currently considered the gold standard for flexible bronchoscopic intubation (FBI). In our study, although the time for FBI was used as the primary outcome, it did not include the time required for placing the AuraGain. For the patients’ safety, we started the intubation process only when sufficient ventilation had been established with the AuraGain. We used a Unoflex (ConvaTec Ltd, Flintshire, UK) endotracheal tube (ETT) because it easily adapted to the contour of the bronchoscope and the SGA. The intubation process was considered complete once correct ETT placement had been confirmed, the bronchoscope removed, and the ETT connected to the ventilator. We then left the AuraGain (together with the ETT) in situ for the whole surgical procedure. Admittedly, having an AuraGain and an ETT together in place for that length of time could result in side effects (i.e., airway morbidity) due to the additional volume of the laryngeal mask airway. Our outcome measures for airway morbidity were chosen according to previous literature. Three parameters were used to assess airway morbidity: dysphagia, hoarseness, sore throat. Our results showed that there was no difference between having an ETT or an ETT and SGA in situ for the entire surgical procedure, independent of postoperative pain therapy. We agree, however, that the degree of sore throat (neck pain) may be related to the pain treatment. One important reason for leaving both devices (AuraGain and ETT) in situ until extubating criteria are reached is reflected in the recent guidelines for difficult airways. As our research group is currently investigating the use of SGA devices for difficult airway management, we followed the guideline stating that patient safety requires that, once a safe airway has been established, unnecessary manipulation should be avoided. In this first trial in patients without a difficult airway, we showed safe and effective intubation and ventilation with no patient morbidity. This is a critical step for continuing our investigations that include patients with a difficult airway.

Oropharyngeal leak pressure of the LMA Protector™ vs the LMA Supreme™; a prospective, randomized, controlled clinical trial

Clinical characteristics such as oropharyngeal leak pressure (OLP) and ventilation peak pressure are important factors for successful use of supraglottic airway devices in general anaesthesia. We hypothesized that the LMA Protector™ compared to the LMA Supreme™ may develop a higher OLP, which could be of clinical significance.

Fiberoptic intubation of severely obese patients through supraglottic airway: A prospective, randomized trial of the Ambu® AuraGain™ laryngeal mask vs the i-gel™ airway

Airway management in severely obese patients remains a challenging issue for anaesthetists and may lead to life‐threatening situations. Supraglottic airway devices, such as the i‐gel™ or the AuraGain™, were developed, with the possibility to ventilate the patient or use them as a conduit for endotracheal intubation.