Effect of rewarming in oxygenation and respiratory condition after neonatal exposure to moderate therapeutic hypothermia.

BACKGROUND

To assess changes in clinical condition and oxygenation in neonates after rewarming following moderate therapeutic hypothermia (MTH) for neonatal encephalopathy.

METHODS

Retrospective study of 28 neonates receiving MTH in a tertiary neonatal intensive care unit in Israel. We compared pre-and 24 h post-rewarming arterial oxygen saturation (SaO) as measured by the blood gases analyzer, pulse-oximetry saturation (SpO), and cardio-respiratory condition.

RESULTS

The SpO declined from 96.9% (±2.9) before rewarming to 95.2% (±2.6) after rewarming (p < 0.001). Twelve neonates (42.9%) had clinical respiratory impairment (needing higher respiratory support or had new onset desaturations). In 16 neonates (57.1%) with no change in respiratory support after rewarming, SpO decreased from 98.3 ± 1.9% to 95.6 ± 3.0% (p < 0.001) and SaO decreased from 97.1 ± 1.7% to 96.0 ± 2.3% (p = 0.002). The mean SpO decrease was greater than mean SaO decrease (2.63 ± 1.8 and 1.1 ± 1.3 respectively, p = 0.021).

CONCLUSION

Neonates who underwent MTH showed reduction in oxygenation after rewarming either by decreasing SpO or increasing FiO requirements. The SpO decline was larger than the SaO decline. We suggest careful monitoring of neonates after rewarming.