Socarras Jorge Luis Alvarado, Martin Delia Edith Theurel, Hernández Edgar Fabian Manrique
Pediatrics Department, Fundación Cardiovascular de Colombia, Neonatal Intensive Care Unit, Bucaramanga, Colombia.
Epidemiology Department, Fundación Cardiovascular de Colombia, Floridablanca, Colombia.
Curr Drug Discov Technol. 2022;19(5):e200522205067. doi: 10.2174/1570163819666220520112220.
Adequate oxygenation is essential for sick newborns. Each disease determines the target of oxygenation. Nevertheless, hyperoxia and hypoxia are related to adverse outcomes. Most studies related to this aspect have been conducted in preterm infants or term babies with pulmonary pathology.
Congenital heart diseases may also require careful oxygenation control and management of oxygen supply.
Presurgical stabilization of complex heart diseases (CHD) may be difficult, especially after the physiological decrease of pulmonary resistance, which generates pulmonary edema (due to overcirculation) and systemic hypoperfusion. Several strategies have been described to avoid this phenomenon, such as prostaglandin, vasodilators, inotropes, positive airway pressure, and even hypoxic mixture (inspired fraction of oxygen (FiO2) below 21%).
The latter therapy is mainly used in single ventricular physiology heart diseases, such as the hypoplasic left heart syndrome (HLHS) or systemic ductus-dependent flow CHD (interruption of the aortic arch and coarctation of the aorta). Alveolar oxygen affects pulmonary vascular resistance modifying lung flow. This modification could help the stabilization during the presurgical period of complex CDH. Many centers use hypoxic therapy to avoid hypotension, metabolic acidosis, coronarycerebral ischemia, and liver, renal and intestinal injury. Despite the theoretical benefits, there are doubts about how tissue oxygen supply would change during hypoxic gas ventilation. It is worrisome that FiO < 21% causes a decrease in brain oxygenation, adding neurological injury as a complication to the already established disease of CHD and other not modifiable factors. Brain monitoring through near-infrared spectroscopy (NIRS) during hypoxic gas therapy is mandatory. Recent studies have shown that hypoxic gas ventilation therapy in patients with HLHS in the preoperative period decreases the ratio between systemic and pulmonary circulation (Qp/Qs) but does not improve regional oxygenation delivery. The use of hypoxic gas ventilation therapy continues to be controversial. It could be an option in some complex CHD, mainly HLHS.
充足的氧合对于患病新生儿至关重要。每种疾病都决定了氧合的目标。然而，高氧和低氧均与不良结局相关。大多数关于这方面的研究是在患有肺部疾病的早产儿或足月儿中进行的。
先天性心脏病也可能需要仔细控制氧合并管理氧气供应。
复杂心脏病（CHD）术前的稳定可能很困难，尤其是在肺阻力生理性降低之后，这会导致肺水肿（由于过度循环）和全身灌注不足。已经描述了几种避免这种现象的策略，例如使用前列腺素、血管扩张剂、强心剂、气道正压通气，甚至是低氧混合气（吸入氧分数（FiO2）低于21%）。
后一种疗法主要用于单心室生理的心脏病，如左心发育不全综合征（HLHS）或依赖体循环导管的血流CHD（主动脉弓中断和主动脉缩窄）。肺泡氧会影响肺血管阻力，从而改变肺血流。这种改变有助于复杂CHD术前的稳定。许多中心使用低氧疗法来避免低血压、代谢性酸中毒、冠状动脉和脑缺血以及肝、肾和肠损伤。尽管有理论上的益处，但对于低氧气体通气期间组织氧供应将如何变化仍存在疑问。令人担忧的是，FiO < 21%会导致脑氧合下降，使神经损伤成为已确诊的CHD疾病以及其他不可改变因素之外的一种并发症。在低氧气体治疗期间，通过近红外光谱（NIRS）进行脑监测是必不可少的。最近的研究表明，术前对HLHS患者进行低氧气体通气治疗会降低体循环与肺循环的比率（Qp/Qs），但不会改善局部氧输送。低氧气体通气治疗的使用仍然存在争议。它可能是某些复杂CHD（主要是HLHS）的一种选择。
