Laryngeal mask as an option for positive pressure ventilation of newborns in the delivery room

Abstract

Although the child mortality rate has been decreasing worldwide, the neonatal death rate has remained high. In Brazil, according to official statistics from 2013, neonatal mortality was responsible for 69% of the deaths. According to the Brazilian Pediatric Society, from 2005 to 2010, there were 5 to 6 early deaths daily associated with perinatal asphyxia in low-risk newborns (NB), weighing at least 2.5 kg and without congenital malformation. The majority of these deaths has occurred on the first day of life, suggesting causes related to delivery and birth. At birth, adverse events can cause failure in the transition from intra to extrauterine life, making the NB unable to breathe well thus, increasing the death risk and brain damage by asphyxia. According to literature, 1 out of 10 NB needs resuscitation maneuvers through positive pressure lung ventilation (PPV) to establish effective breathing. The PPV, critical point to a successful resuscitation, is so important and effective at the delivery room resuscitation that 9 out of 10 NB get better and do not require advanced resuscitation maneuvers. This procedure is usually performed with specific ventilation equipment, a self-inflating bag or mechanical ventilator, attached to two kinds of devices, a face mask (FM) or an endotracheal tube (ETT). Both of them have peculiarities as to manipulation, and their efficiency will vary according to the skills and training of the professional in charge. Failure of the PPV often occurs because of the bad adaptation of the FM, with air leak around it, which requires intubation. However, neonatal intubation is a complex and invasive procedure, which demands a higher training level of the professional. If performed inappropriately it may result in unwanted increased PPV time, thus increasing death or morbidity risk. Studies show that such risk grows 16% every 30 seconds of unsuccessful ventilation. Considering these difficulties and limitations, the so-called Laryngeal Mask Airway (LMA) can be a good alternative to PPV, since it is able to provide appropriate lung ventilation. Among its advantages we can name its simple handling, little possibility of air leak, and the fact that it is less invasive than ETT, what is relevant, considering the possibility of neonatal resuscitation being performed by professionals with different levels of experience. The aim of this study is to evaluate the time spent to perform an effective PPV using FM, ETT or LMA, by inexperienced students in neonatal resuscitation. This experimental and prospective study, using simulation dummy to neonatal resuscitation, with voluntary participation of 6th-year medical students with no delivery room neonatal resuscitation training. After a brief training, a simulated neonatal resuscitation situation will be proposed and the participants will be instructed to proceed with a PPV using the 3 devices. The variables studied will be as follows: time to first insufflation (T1), a number of insertion attempts, time to obtain effective PPV (T2) and the respiratory parameters. PPV will be considered effective when the values of inspiratory pressure (IP) and positive end-expiratory pressure (PEEP) are reached and the flow curves and tidal volume (TV) established. Such parameters will be obtained by a pneumotachograph linked to a computerized data acquisition system. The study will be performed at the Neonatal Lung Physiopathology Laboratory of Experimental Research Unity of Botucatu Medical School - UNESP. The project was approved by the Ethics Committee in Research and Medical Graduation Course Council of the Institution. The hypothesis of the study is that the laryngeal mask can be a practical and efficient device, capable of guaranteeing effective PPV in an adequate time, even if it is handled by individuals without experience in neonatal resuscitation.