Cerebrovascular autoregulation and preterm brain injury: a systematic review and meta-analysis.

BACKGROUND

Preterm neonates are vulnerable to impaired cerebrovascular autoregulation (CAR), with a risk of developing cerebral injury (intraventricular hemorrhage or periventricular leukomalacia). In this meta-analysis, we evaluate the association between the degree of CAR and cerebral injury in preterm neonates, using various CAR assessment techniques mainly based on near-infrared spectroscopy.

METHODS

We systematically searched PubMed and EMBASE between 01-05-2023 and 31-01-2024. We included original articles published between 2000-2023, reporting CAR and cerebral injury in preterm neonates. The study was registered in PROSPERO (ID: 427323). We assessed the standardized mean difference in degree of CAR in groups with and without cerebral injury, with a subgroup analysis of CAR measurement techniques.

RESULTS

Seventeen articles were included, encompassing 742 patients. The overall standardized mean difference of 0.59 (95%CI 0.30, 0.88) indicates more impaired CAR in neonates with cerebral injury. Time-domain analysis produced the least heterogeneous and most significant difference of 0.61 (95%CI 0.24, 0.98). Limitations include differences in measurement techniques and a lack of randomized controlled trials.

CONCLUSION

This meta-analysis showed an association between CAR and cerebral injury, highlighting the clinical relevance of CAR assessment in preterm neonates. Future randomized studies using standardized measurement techniques should assess the feasibility of CAR-guided hemodynamic management.

IMPACT

Cerebral injury and adverse neurological outcomes are prevalent in preterm neonates. Historically, immature cerebrovascular autoregulation was thought to be one of the main causes of cerebral injury in this patient population. This is the first study to systematically review and synthetize robust evidence on the relation between cerebrovascular autoregulation and preterm brain injury. This meta-analysis further adds to the existing literature by comparing different cerebrovascular autoregulation measurement techniques. The findings can help to standardize cerebrovascular autoregulation assessment and implement it in clinical practice using large, randomized trials.