Eiby Yvonne A, Lingwood Barbara E, Wright Ian M R
Faculty of Medicine, Perinatal Research Centre, Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia.
Department of Neonatology, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.
Front Neurol. 2021 Aug 2;12:636740. doi: 10.3389/fneur.2021.636740. eCollection 2021.
Preterm infants are at high risk of death and disability resulting from brain injury. Impaired cardiovascular function leading to poor cerebral oxygenation is a significant contributor to these adverse outcomes, but current therapeutic approaches have failed to improve outcome. We have re-examined existing evidence regarding hypovolemia and have concluded that in the preterm infant loss of plasma from the circulation results in hypovolemia; and that this is a significant driver of cardiovascular instability and thus poor cerebral oxygenation. High capillary permeability, altered hydrostatic and oncotic pressure gradients, and reduced lymphatic return all combine to increase net loss of plasma from the circulation at the capillary. Evidence is presented that early hypovolemia occurs in preterm infants, and that capillary permeability and pressure gradients all change in a way that promotes rapid plasma loss at the capillary. Impaired lymph flow, inflammation and some current treatment strategies may further exacerbate this plasma loss. A framework for testing this hypothesis is presented. Understanding these mechanisms opens the way to novel treatment strategies to support cardiovascular function and cerebral oxygenation, to replace current therapies, which have been shown not to change outcomes.
早产儿因脑损伤面临着高死亡风险和残疾风险。心血管功能受损导致脑氧合不足是这些不良后果的重要原因，但目前的治疗方法未能改善预后。我们重新审视了有关血容量不足的现有证据，并得出结论：在早产儿中，循环中血浆流失会导致血容量不足；这是心血管不稳定进而导致脑氧合不足的重要驱动因素。高毛细血管通透性、改变的流体静压和胶体渗透压梯度以及淋巴回流减少共同作用，增加了毛细血管处血浆从循环中的净流失。有证据表明，早产儿会出现早期血容量不足，且毛细血管通透性和压力梯度的变化均会促使毛细血管处血浆快速流失。淋巴流动受损、炎症以及一些当前的治疗策略可能会进一步加剧这种血浆流失。本文提出了一个验证该假设的框架。了解这些机制为支持心血管功能和脑氧合的新治疗策略开辟了道路，以取代目前已证明无法改变预后的治疗方法。
