Influence of head and neck position on the performance of supraglottic airway devices: A systematic review and meta-analysis

Abstract

Background Changes in head and neck position may significantly affect the performance of supraglottic airway devices (SADs) by altering the pharyngeal structure. Purpose This systematic review and meta-analysis aimed to elucidate the effect of changes in head and neck position on performance of SADs. Data source Bibliographic databases, including PubMed, EMBASE, the Cochrane library, and the Web of Science. Study eligibility criteria Prospective studies investigating the effects of head and neck positions on the performance of SADs. Methods A random effect model was applied in the all analyses. Subgroup analysis was performed according to the type of device and the age of patient. The oropharyngeal leak pressure was the primary outcome measure. Secondary outcome measures included peak inspiratory pressure, fibreoptic view, and ventilation score (PROSPERO, CRD42017076971). Results Seventeen studies met the eligibility criteria. Overall, the oropharyngeal leak pressure significantly increased (mean difference 4.07 cmH 2 O; 95% confidence interval 3.30 to 4.84) during neck flexion with adverse effects on ventilation and fibreoptic view. Conversely, the oropharyngeal leak pressure decreased (mean difference − 4.05; 95% confidence interval − 4.90 to − 3.20) during neck extension with no significant effect on ventilation or fibreoptic view. Rotation of the head and neck did not significantly affect SAD performance. Conclusions The reduced oropharyngeal leak pressure in the extended neck position was not associated with impaired ventilation except with the air-Q self-pressurizing airway. The flexed neck position significantly worsens ventilation and the alignment between the SAD and glottis despite improving the seal except with the air-Q self-pressurizing airway and LMA Proseal.

Canadian Airway Focus Group updated consensus-based recommendations for management of the difficult airway: part 2. Planning and implementing safe management of the patient with an anticipated difficult airway

“…52 With respect to ventilation once placed, a systematic review and meta-analysis by Kim and colleagues compared the performance of a variety of SGAs in the flexed, neutral, and extended positions. 110 Compared with the neutral position, the flexed position improved device seal but impaired ventilation as well as the view of the glottis obtainable with flexible endoscopy. Conversely, compared with the neutral position, the extended position worsened the device seal but had no effect on ventilation effectiveness or endoscopic view.…”

Safety, efficacy and airway complications of the flexible laryngeal mask airway in functional endoscopic sinus surgery: A retrospective study of 6661 patients

“…on supraglottic airway device ventilation [19,20]. In our study, fourteen cases (0.2%) failed after changing the head and neck position; however, forty-six cases (0.7%) failed intraoperatively, when the position of the patient's head was rarely changed.…”

Efficacy of laryngeal mask airway against postoperative pharyngolaryngeal complications following thyroid surgery: a systematic review and meta-analysis of randomized controlled studies

“…Nevertheless, one of the reported disadvantages of LMA compared to ETT was a lower sealing pressure and a higher incidence of gastric insufflation associated with the former 32 . Despite the previous finding that the performance of LMA may be affected by changes in head and neck position that unavoidably alter the pharyngeal structures 48 , 49 , a previous meta-analysis demonstrated no correlation between an extended neck position and an impairment in ventilation in most type of LMA 50 . Furthermore, previous evidence showed no difference in the incidence of desaturation, regurgitation, gastric insufflations, and pulmonary aspiration between LMA and ETT in the general population 15 , 51 , 52 .…”