For the critical outcome of mortality, there is evidence from 36 observational studies of increased risk of mortality associated with hypothermia at admission (Buetow 1964, 163; Stanley 1978, 300; Levi 1984, 975; Obladen 1985, 181; Bhoopalam 1991, 57; Daga 1991, 53; Hazan 1991, 111; Bateman 1994, 147; Harms 1994, 126; Costeloe 2000, 659; Pal 2000, F46; da Mota Silveira 2003, 115; Kambarami 2003, 103; Manji 2003, 23; Wyckoff 2004, 191; Acolet 2005, 1457; Mathur 2005, 341; Zayeri 2005, 1367; Laptook 2007, e643; Kent 2008, 325; Lee 2008, 754; Ogunlesi 2008, 40; Sodemann 2008, 980; Mullany 2010, 650; Jones 2011, 181; Miller 2011, S49; A Abd-El Hamid 2012, 104; Costeloe 2012, e7976; Shah 2012, e000792; Singh 2012, 33; Boo 2013, 447; Manani 2013, 8; de Almeida 2014, 271; Garcia-Munoz Rodrigo 2014, 144) (F Nayeri 2006, 48; Kalimba 2013, 13) (low-quality evidence but upgraded to moderate-quality evidence due to effect size, dose effect, and single direction of evidence). There is evidence of a dose effect on mortality, suggesting an increased risk of at least 28% for each 1° below 36.5°C body temperature at admission (Laptook 2007, e643; Mullany 2010, 650) and dose-dependent effect size. (Laptook 2007, e643; Mullany 2010, 650; Miller 2011, S49; Boo 2013, 447) One small randomized clinical trial (Meyer 2001, 395) (very-low-quality evidence, downgraded for indirectness and serious imprecision) showed a reduction in adverse events, including death, intracranial hemorrhage, necrotizing enterocolitis, and oxygen dependence with improved temperature management, but 3 randomized controlled trials (Vohra 1999, 547; Vohra 2004, 750; Reilly 2015, 262) (low-quality evidence, downgraded for indirectness and imprecision) did not show any significant improvement in mortality with significantly improved temperature control. Four observational studies (Kent 2008, 325; Lee 2008, 754; Billimoria 2013, 455; Manani 2013, 8) (very-low-quality evidence, downgraded for indirectness and imprecision) did not find any improvement in mortality with improved admission temperatures, but they were not sufficiently powered for this outcome.For the critical outcome of IVH, 8 observational studies (very-low-quality evidence, downgraded for risk of bias and indirectness) show hypothermia (temperature less than 36°C) in preterm infants is associated with an increased likelihood of developing IVH.(Van de Bor 1986, 1125; Herting 1992, 26; Gleissner 2000, 104; Bartels 2005, F53; Carroll 2010, 9; Miller 2011, S49; Boo 2013, 447; Garcia-Munoz Rodrigo 2014, 144) Eight observational studies (low-quality, downgraded for indirectness) found no association between hypothermia and IVH. (Levene 1982, 410; Szymonowicz 1984, 13; Dincsoy 1990, 245; Laptook 2007, e643; Kent 2008, 325; Lee 2008, 754; Audeh 2011, 373; Rong 2012, 2077)For the important outcome respiratory issues, there is evidence from 9 observational studies(Harms 1997, 258; Costeloe 2000, 659; Bartels 2005, F53; Zayeri 2005, 1367; A Abd-El Hamid 2012, 104; Boo 2013, 447; DeMauro 2013, e1018; Lee 2014, e1378; Russo 2014, e1055) (low-quality evidence) showing an association between hypothermia and respiratory disease. One large randomized controlled trial (Reilly 2015, 262-268) (low-quality evidence, downgraded for imprecision and risk of bias) found a reduction in pulmonary hemorrhage associated with improved admission temperature (OR, 0.57; 95% CI, 0.35–0.94). Eight observational studies (very-low-quality evidence) have shown an improvement in respiratory outcomes after improved admission temperature maintenance. (Buetow 1964, 163; Carroll 2010, 9; A Abd-El Hamid 2012, 104; Costeloe 2012, e7976; Singh 2012, 33; DeMauro 2013, e1018; Manani 2013, 8; Lee 2014, e1378) Two of these have shown a decrease in respiratory support with improved temperature maintenance. (DeMauro 2013, e1018; Russo 2014, e1055) Two observational studies (very-low-quality evidence, downgraded for indirectness and imprecision) did not show any association. (Laptook 2007, e643; Kent 2008, 325)For the serious outcome of hypoglycemia, there were seven observational studies (very-low-quality, downgraded for risk of bias and indirectness) showing a significant association between hypothermia (less than 36°C) and hypoglycemia.(Anderson 1993, 273; Pal 2000, F46; Lenclen 2002, 238; Sasidharan 2004, 110; Zayeri 2005, 1367; Lazic-Mitrovic 2010, 604; A Abd-El Hamid 2012, 104) Two of these studies, using historical controls, showed improved glycemic control with improved normothermia.(Lenclen 2002, 238; A Abd-El Hamid 2012, 104)For the serious outcome of late sepsis, 2 observational studies (very-low-quality evidence, downgraded for risk of bias and indirectness) indicated an association between hypothermia on admission and late sepsis.(Laptook 2007, e643; Mullany 2010, 426) One observational study (low-quality, downgraded for risk of bias and indirectness) found no association after multivariate analysis.(Miller 2011, S49)For the serious outcome of survival to admission, there is no published evidence addressing any effect of delivery room hypothermia upon survival to admission.For the serious outcome of admission hyperthermia, there is no published evidence about newborn hyperthermia at admission. |