Randomized Controlled Study Of Using Laryngeal Mask Airway In The Premature Resuscitation

[Background]With the development of perinatal medicine and the promotion of neonatal resuscitation, adequate care to newborn infants in the delivery room is essential so as to prevent asphyxia lesions, which cause neonatal death and neurological sequelae in those who survive, impairing their quality of life and of their families as well. Neonatal mortality, amounting to an estimated4million deaths worldwide each year, and intrapartum hypoxia or asphyxia has to be considered as the third most common cause of newborn death (23%) after infections (36%) and preterm birth (28%), especially asphyxia is the major cause of premature death. Most preterm infants need extra inspiration support due to the immature lungs and so on, this makes the resuscitation more important for preterm infants. So to improve the technology of resuscitation not only preventing the asphyxia incidence, but induce the mortality and the morbidity of nervous system sequel.It’s important and far-reaching significant for the overall health development and national health services level.Routine use of bag-mask ventilation and endotracheal intubation both have drawbacks. Recently there are more and more controversies about laryngeal mask airway (LMA). February2010, the committees for neonatal resuscitation of American Academy of Pediatrics and June2011, the Chinese experts group of neonatal resuscitation, developed guidelines for the recommendation the use of LMA. LMA was designed in1981by the British anesthetist Dr Archie Brain as a subglottic airway device, and it can quickly establish the airway for effective ventilation within short time in emergency situations. But the Size1LMA is currently recommended for infants weight≥2kg and gestation age≥34w, but its use in preterm infants or VLBWI are limited. The study about operations feasibility, efficacy and adverse reaction of use LMA ventilation.The study use randomized control trail and discusse the operations details, efficacy and adverse reactions, to assess the feasibility, effectiveness and safety of preterm resuscitation.[Objective and Clinical significance]According to the retrospective survey of80hospitals from22provinces and autonomous regions in China, asphysia is the second direct cause of neonatal mortality and accounting for49.2%of all death had asphyxia. The incidence of asphyxia in preterm infants are higher than fullterm infants. Qiao had reported that the mortality of in-patient is2.7%, and preterm birth is the leading direct cause (43.3%). How to rapidly providing effective assisted ventilation is the emphasis of NICU. And the survival and disability rate also reflects the medical level of the region or even the whole country. We designed study to explore the feasibility, efficacy and safety of utilizing LMA ventilation in preterm infants especially VIB WI.Compare the differences and effects between LMA and face mask. And expect to decrease the resuscilation successful rate and the complications. To promote the use of laryngeal mask in neonatal resuscitation, especially the application in the basic-level hospitals have great significant, not only decrease morbidity of babies, but decrease the cost of family and community. It can promote and implement national policy of eugenic and superior nurture.[Methods]1objectA randomized controlled study of the use of LMA in preterm infants’ resuscitation was conducted for about one and a half years (January2011-September2011) at the Shenzhen Maternal&Child Health Hospital, affiliated to Southern Medical University. Inclusion criteria for the70newborns selected were a gestational age between28～34weeks or an expected birth weight between1.0～2.0kg, and the need for positive pressure ventilation with a heart rate<100beats per min (bpm), gasping or apnea at birth after initial resuscitation measures (providing warmth, positioning, clearing the airway, drying and stimulation) over the first30s, or by the presence of persistent central cyanosis despite receiving supplementary oxygen. Exclusion criteria included still-births, severe prenatal depression (with Apgar score nearly0at1min after birth), major malformations of the respiratory system or cyanotic congenital heart disease.The study was approved by the institutional ethics committee and informed consent was obtained from parents.2GroupingNeonates who meet the inclusion criteria were randomised to the IMA (size-1LMA-ClassicTM The Laryngeal Mask Company Limited, UK) group (35cases) or the FM group (35cases) in advance according to random number table.3ResuscitationThe standard LMA insertion technique described by Brain was used. The LMA was held in place and connected to a self-inflating bag for positive pressure ventilation. During resuscitation, inhaled oxygen concentration close to30～40%can be used in initial, and then the concentration delivered should be guided by oximetry. Positive pressure ventilation was given at40-60breaths per min with oxygen. If heart rate between60～100bpm or increasing trend after30s positive pressure ventilation, it can continuation ventilation. If heat rate less than60bpm, endotracheal ventilation could be used. Endotracheal suctioning could be used in infants born through meconium-stained amniotic fluid, even when the newborn is depressed.4Operation index(1) LMA insertion time:the time insert in the LMA to ventilation;(2) the rate of successful insertion at the first attempt, and the number of attempts required to insert the LMA successfully;(3) Inflation volume:the air inflated in LMA cuff;(4) Insert depth:the top of LMA to the lip. 5Observation indexThe following data was collected during resuscitation:(1) Apgar score at1min and5mins after birth;(2) Successful resuscitation rate of both groups. Failure was defined as when LMA or FM had to be replaced by ET for two groups;(3) Resuscitation response time (the time period from starting LMA resuscitation to achieving an effective response);(4) Ventilation time (the time from the beginning to establish an effective ventilation to recovery spontaneous breathing);(5) Adverse effects during resuscitation;(6)Arterial blood gases, blood sugar level and lactic acid before and after resuscitation from each group;(7) Follow-up:Complications, length of stay, hospitalization costs.6Statistical analysisData was analyzed using SPSS13.0. Test of normality was used for continuous variables. Normally distributed data were reported as means and standard deviations. Skewed distribution data were analyzed after natural logarithmic transformation and reported as median and interquartile range. Independent t-tests were used for normally distributed data, and nonparametric tests for abnormally distributed data and nonparametric variables. chi-square tests were used for categorical data, and exact probability tests were used for categorical data which was not suitable for chi-square test. P≤0.05was considered as a statistically significant difference.Results1There are no statistically significant difference in delivery way, weight, gestational age, sex between two groups.2Rate of successful first insertion was94.3%with an average inserting time of (8.8±1.38) s for LMP group;Mean insert depth is6.7±0.98cm; There are significant difference in inserting time and the rate of successful first insertion between LBW1and VLBW1(P<0.05). 3No significant difference was observed in Apgar scores at1min, but Apgar scores at5min was higher in LMA group (p>0.05).4Successful resuscitation rate of LMA group (88.6%) was higher than FM group(40%), it has significant difference.5Mean response time of the LMA group[(16.9±4.3)s] was shorter than the FM group[(22.6±5.3)s], also ventilation time of LMA group[(56.8±24.7)s] was slightly lower than the ET group[(103.6±43.8) s], but both showed significant statistical differences (P<0.05).6There was no difference between the LMA and FM groups in arterial blood gas values, glucose levels and lactic acid before and after resuscitation, but the D-value of PO2of blood gas in LMA group[(72.1±13.8)mmHg] was higher than FM group [(64.5±10.0)mmHg].7Five points of dynamic monitoring according to Pulse oximeter showed the pulse and oxygen saturation at60s were higher in LMA group, it has significant statistical differences (P<0.05).8Adverse reactions found in LMA group including nausea (1cases) and gastroesophageal reflux (2cases), there is no abdominal distention, while those found in the FM group included gastroesophageal reflux (lcases), abdominal distention (2cases), and there is no nausea. There was no other severe adverse effects (e.g., laryngospasms) in either group.There was no significant difference in the incidence of adverse effects between the two groups.9Follow-up:The LMA Group showed3deaths, and4case unthreated after resuscitation; the FM Group howed3deaths, and6case unthreated after resuscitation. With only6cases in LMA Group and9cases in FM Group have mild or moderate intracranial hemorrhage, all recovered. One HIE cases in FM groups were cured. There are no significant difference in length of stay and hospitalization costs between two groups.[Conclusions]LMA ventilation is much easier to operate, with its effectiveness better than that of FM ventilation on resuscitation for preterm infants especially for VLBWI. Infact it even seems safer and greatly decreased the intubation rate. Its reliability when used by multiple users or inexperienced and might be the routine resuscitation method in preterm infants, especially for primary hospital doctors in emergency cases.