Present Situation Of Admission Hypothermia And Its Relationship With Outcome In Both Very Low And Extremely Low Birth Weight Infants In Shandong Province:a Multicenter Survey

ObjectiveTo study the current situation of admission hypothermia in very low birth weight infants(VLBW)and extremely low birth weight infants(ELBW)in multicenter neonatal intensive care units(NICU)of Shandong province and to further analysis its risk factors and relationship with infants’ outcome,and then to provide clinical evidence for quality improvement in reducing the incidence of admission hypothermia in NICU.MethodsFirstly,a retrospective questionnaire survey was conducted in VLBW/ELBW infants admitted to NICUs of 24 tertiary hospitals in Shandong province from January 1 to December 31,2017.Information on distribution and methods of measuring temperature on admission,and the implementation of 20 measures to prevent hypothermia were collected.The correlation between the preventive measures of hypothermia and the incidence of admission hypothermia was analyzed by descriptive statistical methods and Spearman analysis.Meanwhile,since January 1,2018,neonatal homogeneous cooperative research platform of Ningbeixin(http://www.ningbx.com/index/login/login.html)were established.The admission temperature of inborn VLBW/ELBW infants in 24 NICUs in Shandong province and their incidence of mortality and morbidity data was collected prospectively.Temperature criteria were based on the World Health Organization(WHO)classifications of hypothermia and associations between predictor variables and hypothermia were tested in a univariate analysis,followed by stepwise logistic regression with division into normothermic and hypothermic infants.Separate models were constructed for combined severe/moderate and mild hypothermia.We then studied the potential contribution of hypothermia to neonatal outcomes.Outcome parameters were compared by using the x2 test for categorical variables.Multivariate analyses were performed using the logistic regression model to identify the implications of hypothermia with respect to outcomes,for example respiratory distress syndrome(RDS),intraventricular hemorrhage(IVH)(Papile grade 3 or higher),necrotizing enterocolitis(NEC)(Bell stage 2 or higher),late onset neonatal sepsis(LOS),bronchopulmonary dysplasia(BPD)(defined as oxygen dependency at 36 weeks’corrected gestational age or the time of transfer to a level 2 center),retinopathy of prematurity(ROP)(stage 3 or higher),extrauterine growth retardation(EUGR)and so on.Associations between mortality and hypothermia were tested in a univariate analysis,followed by stepwise logistic regression with division into survival group and the death group.Results1.The 24 recruited hospitals included 16 general hospitals and eight maternal and child health care hospitals with an average beds in Neonatology Department and NICU of 59 and 40,respectively.A total of 50 445 newborns in NICUs were enrolled,of which 17 312(34.3%)premature infants.The 2 693 VLBW/ELBW infants were included in this analysis,of which 2 279 VLBW infants(13.2%)with birth weight≥1000-1500 g and 414(2.4%)ELBW infants with birth weight<1000 g.The incidence of admission hypothermia was 89.3%(2 406/2 693)in VLBW/ELBW infants in the 24 NICUs,in which VLBW infants and ELBW infants were 89.3%(2035/2 279)and 89.6%(371/414),respectively.The median number[M(P25-P75)]of the measures implemented to prevent hypothermia was 10.5(8.3-14.0)in the 24 NICUs.Only less than 50%of the 24 NICUs carried out the following measures:wrapping newborns in plastic film(three pieces for head,body and lower limbs respectively),putting on a pre-warmed hat,quick weighing after the newborns being placed in a pre-warmed blanket,measuring and recording body temperature 10 min after birth,transferring newborns from delivery room to NICU in transport incubator,reporting chart on hypothermia in preterm infants on admission to NICU monthly,implementing the quality improvement project to reduce hypothermia in preterm infants on admission to NICU.Axillary temperature tested with mercury thermometer on admission was the most common method used in the 24 hospitals[79.2%(19/24)];mostly was measured under the arm for 5 min accompanying by nurses with mercury thermometer[45.8%(11/24)].There was a negative correlation between the incidence of admission hypothermia and the number of quality improvement measures implemented to prevent hypothermia(r=-0.262,P<0.05).2.We established the neonatal homogeneity platforms(http://www.ningbx.com/index/login/login.html).The data of all inborn infants with birth weight<1500 g from January 2018 and December 2018 were prospectively collected in the 24 level III NICUs.A total of 1642 VLBW and ELBW infants enrolled,of which 109 infants were excluded owing to not born at oneself hospital.Additionally,93 infants with missing temperature data were excluded.The remaining 1440 infants were included in this analysis,of which 1203 VLBW infants(83.5%)with birth weight≥1000-1500 g and 237(16.5%)ELBW infants with birth weight<1000 g,and 237(16.5%)cases of deaths and 1203(83.5%)cases of survivals.Those infants had a mean(±s.d.)birth weight,gestational age and admission temperature of 1210 ± 216 g,29,5 ± 2.7 weeks and 35.8 ± 0.6℃,respectively.There were 181 infants(12.6%)in the normothermia group and 1259 infants(87.4%)in the hypothermia group,including 610 infants(42.4%)in the mild hypothermia group,and 649 infants(45.1%)in the moderate/severe hypothermia group.There were no other clinical signs of hyperthermia in this study.Multivariate Logistic regression analysis of the risk factors for admission hypothermia showed that compared with the normal body temperature group,SGA(OR 0.5,95%CI 0.3-0.9;P=0.03),Multiple birth(twin and above)(OR 0.6,95%CI 0.4-0.9);P=0.03),cesarean section(OR 0.6,95%CI 0.4-0.9;P=0.01),Antenatal steroids(OR 0.5,95%CI 0.3-0.7;P=0.001),5min Apgar scores(OR 0.7,95%CI 0.6-0.9);P=0.001),gestational hypertension(OR 0.6,95%CI 0.4-1.0;P=0.04)were statistically significant.Further subgroup analysis showed that compared with normal body temperature group,the incidence of RDS(OR 0.6,95%CI0.4-0.9;P=0.03)、IVH(OR 0.3,95%CI 0.2-0.7;P<0.001)、LOS(OR 3.2,95%CI 1.9-5.6:P<0.001)和 EUGR(OR 0.5,95%CI 0.3-0.7;P<0.001)were statistically significant in moderate/severe hypothermia group,but the difference between mild body temperature group and normal body temperature group was not statistically significant(P>0.05).VLBW/ELBW infants were divided into death group and survival group.Multivariate logistic regression analysis identified moderate/severe hypothermia(OR 0.7,95%CI 0.5-0.9,P = 0.03),severe asphyxia(OR 0.5,95%CI 0.3-0.8;P=0.006),RDS(OR 0.5,95%CI 0.3-0.9;P=0.01),IVH(OR 0.4,95%Cl 0.2-0.6;P<0.001),EOS(OR 0.5,95%CI 0.4-0.8;P=0.002),LOS(OR 0.6,95%CI 0.4-1.0;P=0.03)and NEC(OR 0.3,95%CI 0.2-0.6;P=0.001)were associated with death.Conclusionsl.The incidence of admission hypothermia was higher(89.3%of 2017 vs 87.4%of 2018,respectively).There was a negative correlation between the incidence of admission hypothermia and the number of quality improvement measures implemented to prevent hypothermia and suggested that the effective implementation of measures to prevent hypothermia can promote the improvement of the quality of admission hypothermia of NICU,which is expected to reduce the incidence of admission hypothermia of VLBW/ELBW infants2.Perinatal factors such as Multiple birth(twin and above),cesarean section,Antenatal steroids,5min Apgar scores,gestational hypertension carried higher odds of hypothermia and suggested that warm keeping measures should be actively taken to maintain normal admission temperature in infants with these high risk factors.3.The incidence of admission hyperthermia was 87.4%in VLBW/ELBW infants,among which the incidence of mild hypothermia and moderate/severe hypothermia were 42.4%and 45.1%respectively.Moderate/severe hypothermia was associated with mortality rates and poor outcomes,such as RDS,IVH,LOS,and so on.