Burden of hypoxia and intraventricular haemorrhage in extremely preterm infants

Abstract

ObjectiveThresholds of cerebral hypoxia through monitoring of near-infrared spectroscopy tissue oxygenation index (TOI) were used to investigate the relationship between intraventricular haemorrhage (IVH) and indices of hypoxia.DesignProspective observational study.SettingA single-centre neonatal intensive care unit.PatientsInfants <28 weeks’ gestation with an umbilical artery catheter.MethodsThresholds of hypoxia were determined from mean values of TOI using sequential Χ2 tests and used alongside thresholds from existing literature to calculate percentage of time in hypoxia and burden of hypoxia below each threshold. These indices were then compared between IVH groups.Results44 infants were studied for a median of 18.5 (range 6–21) hours in the first 24 hours of life. Sequential Χ2 analysis yielded a TOI threshold of 71% to differentiate between IVH (16 infants) and no IVH (28 infants). Percentage of time in hypoxia was significantly higher in infants with IVH than those without, using thresholds of 60%–67%. Burden of hypoxia was significantly higher in infants with IVH than without, using thresholds of 62%–80%. With the threshold of 71%, percentage of time in hypoxia was lower by 12.2% with a 95% CI of (−25.7 to 1.2) (p=0.073), and the burden of hypoxia was lower by 29.2% hour (%h) (95% CI −55.2 to −3.1)%h (p=0.012) in infants without IVH than those with IVH.ConclusionsUsing defined TOI thresholds, infants with IVH spent higher percentage of time in hypoxia with higher burden of cerebral hypoxia than those without, in the first 24 hours of life.

Cardiovascular and cerebrovascular responses to cardio‐respiratory events in preterm infants during the transitional period

“…A significantly lower cerebral oxygenation has been previously reported by several near-infrared spectroscopy studies in preterm infants with a hsPDA compared to those with a non-significant PDA or a closed duct (Lemmers et al 2008;Chock et al 2016;Dix et al 2016;Poon & Tagamolila, 2019), reflecting reduced cerebral blood flow as a result of the significant left-to-right transductal shunting (Kluckow & Lemmers, 2018). These findings suggest that, in infants with a hsPDA, CRE more probably result in a greater degree of cerebral hypoxia, which has been recently proposed as a possible risk factor for IVH development over the first days of life (Ng et al 2019;Vesoulis et al 2019). Moreover, both hsPDA (Shortland et al 1990) and intermittent hypoxia (Juliano et al 2015;Darnall et al 2017) have been associated with a higher risk of periventricular leukomalacia.…”

“…These findings suggest that, in infants with a hsPDA, CRE more probably result in a greater degree of cerebral hypoxia, which has been recently proposed as a possible risk factor for IVH development over the first days of life (Ng et al . 2019; Vesoulis et al . 2019).…”

“…This, in turn, may worsen the impact of CRE on cerebral haemodynamics throughout this period, with possible impairment of cerebrovascular autoregulation. This is suggested by recent evidence of the association between early hypoxic burden and higher rates of intraventricular haemorrhage (IVH) (Ng et al 2019;Vesoulis et al 2019).…”

“…This is suggested by recent evidence of the association between early hypoxic burden and higher rates of intraventricular haemorrhage (IVH) (Ng et al . 2019; Vesoulis et al . 2019).…”

The hidden consequence of intraventricular hemorrhage: persistent cerebral desaturation after IVH in preterm infants

“…This injury may progress in two stages; first from ischemia during the hemodynamically turbulent period following birth and second from prolonged cerebral hypoxia. Previous studies have linked the burden of systemic and cerebral hypoxia to the development of IVH ( 11 , 48 ) and white matter injury ( 49 – 51 ); persistently altered autoregulation may be the common link between the two.…”