BACKGROUND: Supraglottic airways, which are easily inserted and minimize interruptions in cardiopulmonary resuscitation manoeuvres, are now widely used in pre- and in-hospital emergencies. However, most studies in these devices do not specify whether they ensure good ventilation during CPR. This systematic review aims to determine whether there is evidence that supraglotic airways enable effective ventilation during resuscitation.
METHODS: The MEDLINE and COCHRANE databases were searched for studies published in English up to 30 November 2018. Eligible studies were all those that objectively evaluated tidal volume during resuscitation maneuvers in patients over 18 years of age using various supraglottic airways.
RESULTS: A total of 3734 articles were identified, of which 252 were duplicates. Only 1 objectively evaluated ventilation during resuscitation maneuvers and presented data relevant to this review. The study included 470 patients, 51 of which underwent spirometry. Only 4.48% of patients survived to hospital discharge; however, the correlation with ventilation effectiveness was not assessed.
CONCLUSIONS: There is no scientific evidence that supraglottic airways provide effective ventilation during resuscitation maneuvers. Evaluation by spirometry, chest impedance and ultrasound may help to determine the ventilatory efficacy of supraglottic airways during CPR, and clarify whether this factor contributes to the difficulties experienced in reversing cardiorespiratory arrest.

To assess the difference in survival and neurological outcomes between endotracheal tube (ETT) intubation and supraglottic airway (SGA) devices used during out-of-hospital cardiac arrest (OHCA).
A systematic search of five databases was performed by two independent reviewers until September 2018. Included studies reported on (1) OHCA or cardiopulmonary resuscitation, and (2) endotracheal intubation versus supraglottic airway device intubation. Exclusion criteria (1) stimulation studies, (2) selectively included/excluded patients, (3) in-hospital cardiac arrest. Odds Ratios (OR) with random effect modelling was used. Primary outcomes: (1) return of spontaneous circulation (ROSC), (2) survival to hospital admission, (3) survival to hospital discharge, (4) discharge with a neurologically intact state.
Twenty-nine studies (n = 539,146) showed that overall, ETT use resulted in a heterogeneous, but significant increase in ROSC (OR = 1.44; 95%CI = 1.27 to 1.63; I2 = 91%; p < 0.00001) and survival to admission (OR = 1.36; 95%CI = 1.12 to 1.66; I2 = 91%; p = 0.002). There was no significant difference in survival to discharge or neurological outcome (p > 0.0125). On sensitivity analysis of RCTs, there was no significant difference in ROSC, survival to admission, survival to discharge or neurological outcome (p > 0.0125). On analysis of automated chest compression, without heterogeneity, ETT provided a significant increase in ROSC (OR = 1.55; 95%CI = 1.20 to 2.00; I2 = 0%; p = 0.0009) and survival to admission (OR = 2.16; 95%CI = 1.54 to 3.02; I2 = 0%; p < 0.00001).
The overall heterogeneous benefit in survival with ETT was not replicated in the low risk RCTs, with no significant difference in survival or neurological outcome. In the presence of automated chest compressions, ETT intubation may result in survival benefits.