Systematic review of preterm infants′ body temperature at admission and its effects on the clinical outcome

Abstract

Objective To study the distribution of preterm infants′ body temperature at admission and its effects on the clinical outcome. Method The distribution of preterm infants′ body temperature at admission and its effects on their clinical outcome were searched in the Cochrane library, PubMed, Embase, Wanfang, CNKI, VIP from the initial establishment of these databases to June 2018. The quality of the included studies were assessed. STATA 12.0 software was used for statistical analysis. The odds ratio (OR) and 95% confidence interval(CI) were used for continuous variables. Result A total of 16 studies (including 15 clinical trials) with 47 113 cases were included. The incidences of different admission temperatures were as follows:<35℃: 10.3% (7.6%~13.1%), <36℃: 45.3% (35.0%~55.5%), <36.5℃: 63.5% (51.8%~75.2%), 36.5~37.4℃: 35.1% (25.6%~44.7%), ≥37.5℃: 4.2% (2.6%~5.7%). Compared with normothermia (36.5~37.4℃), hypothermia (<35℃, 35~35.9℃, 36~36.4℃) increased the mortality, with the OR and 95%CI as follows: 6.10(4.88~7.62), 1.96(1.45~2.66), 1.31(1.16~1.48); hyperthermia (≥37.5℃) was not associated with higher mortality (OR=0.98, 95%CI 0.73~1.32, P=0.91). Compared with normothermia (36.5~37.4℃), hypothermia (<36℃) increased the risks of severe retinopathy of prematurity (ROP), necrotizing enterocolitis (NEC), sepsis, periventricular leukomalacia (PVL) and intraventricular hemorrhage (IVH), with the OR and 95%CI as follows: ROP: 1.70(1.45~2.00), NEC: 1.27(1.08~1.49), sepsis: 1.44(1.28~1.61), PVL/IVH: 1.26(1.07~1.48), but not the risk of bronchopulmonary dysplasia (BPD, OR=1.03, 95%CI 0.76~1.38, P=0.87). Compared with normothermia (36.5~37.4℃), the temperature between 36~36.4℃ did not increase the risk of severe ROP, NEC, BPD, sepsis, PVL/IVH, with the OR and 95%CI as follows: 1.19(0.92~1.54), 1.01(0.86~1.18), 0.91(0.68~1.22), 1.02(0.91~1.14), 0.98(0.85~1.14). Conclusion Admission temperature of <35℃, 35~35.9℃,and 36~36.4℃ increased the mortality risk compared with 36.5~37.4℃, and the lower admission temperature, the higher mortality risk. Admission hypothermia (<36℃) increased the risk of severe ROP, NEC, sepsis, PVL/IVH compared with normothermia (36.5~37.4℃). Key words: Infant, premature; Body temperature; Mortality; Complications; Meta-analysis