Research On The Application And Evaluation Of Laryngeal Mask Airway In Neonatal Resuscitation

Objective: To compare the efficacy of laryngeal mask airway(LMA) and bag-mask ventilation(BMV) in neonatal resuscitation, and to study the feasibility, efficiency and safety of LMA in neonatal resuscitation.Methods: Totally, 369 neonates requiring positive pressure ventilation(PPV) at birth were randomized into 2 groups by offering either LMA (205 cases) resuscitation or BMV (164 cases) resuscitation. Apgar score at 5min, successful resuscitation rate, ventilation time, the change of heart rate (HR) and arterial blood gas before and after resuscitation, prognosis, the duration and expense of hospitalization and the incidence of associated complications were observed. In LMA group, the insertion time, the rate of successful insertion at the first attempt and adverse effects were also observed.Results: No significant difference was observed in Apgar scores at 1min between LMA group and BMV group, but Apgar scores at 5min in LMA group were higher than BMV group(P=0.001). The successful resuscitation rate of LMA group was higher than BMV group (99.02% vs 84.15%, P<0.001), the total ventilation time of LMA group was shorter than BMV group (36.4s vs 66.2s, P<0.001). With severe asphyxia 77.78% neonates were successfully resuscitated by LMA while in BMV group the neonates with severe asphyxia were all switched to endotracheal intubation(ETI) and ventilation. In neonates with Apgar score of 4-5 at 1min, the successful resuscitation rate of LMA group was higher than BMV group (100% vs 42.86%,P<0.001), the ventilation time of LMA group was shorter than BMV group (54.6s vs 136.4s, P<0.001). In neonates with Apgar score of 6-7 at 1min, there was no significant difference in the successful resuscitation rate between LMA group and BMV group (100% vs 94.12%,P=0.11), but the ventilation time of LMA group was shorter than BMV group (34.9s vs 78.0s,P<0.001). All neonates with Apgar score of 8 at 1min were successfully resuscitated, either in LMA group or in BMV group (both 100%), but the ventilation time of LMA group was less than BMV group (27.8s vs 40.5s,P<0.001). In neonates with Apgar score of 8 at 1min there was no significant difference in the improvement of neonatal HR between LMA group and BMV group, but in neonates with Apgar score of 4-5 or 6-7 at 1min the improvement of LMA group was better than BMV group (P<0.05). In 40 cases the changes of arterial blood gas, lactic acid(LAC) and glucose level before and after resuscitation were no significant difference between LMA group and BMV group.1All neonates survived in LMA group, only one case was forced to discharge by parents against our advice and given up because of congenital malformation. The curative rate of LMA group was 99.51%, no significant difference with BMV group (98.78%). The duration of hospitalization of LMA group was shorter than BMV group (9 date vs 10 date,P=0.02), but there was no significant difference in the expense of hospitalization between two group. The incidence of central nervous system complication in LMA group was lower than BMV group (1.46% vs 5.49%,P=0.03), the incidence of other complications had no significant difference between two groups.In this study the LMA successful insertion rate at first attempt was 98.54%, the insertion time was 7.8s±2.2s, adverse effects were vomiting in 4 cases and regurgitation in 3 cases. In the BMV group adverse effects were abdominal distention by gastric insufflation in 2 cases and regurgitation in 1 case.Conclusion: Technically speaking, LMA is as easy to operate as BMV. In neonatal resuscitation, LMA can be easily inserted. The successful insertion rate at the first attempt can be easily achieved. Using LMA in neonatal resuscitation can lead to a high successful resuscitation rate and a low incidence of mild adverse effects. It is important to clear the amniotic fluid quickly before insertion LMA to avoid regurgitation and aspiration. LMA should be inserted gently along the posterior pharyngeal wall curvature and not be vertical to the mouth.The resuscitation effect of LMA is far better than BMV, almost equivalent to endotracheal ventilation. Compared to BMV, using LMA in resuscitation is the better choice for neonates with moderate-severe asphyxia (Apgar score of 2-5 at 1min), preferable for the medical staffs unfamiliar with ETI, or even as a substitute of endotracheal ventilation.Further assessment is needed for the effect of LMA on neonates with extremely severe asphyxia (Apgar score of 0-1 at 1min) and very low birth weight infants. Endotracheal suction and inhalation treatment can not be applied to new born via LMA method.