Zhou Wei, Liu Wen
Department of Neonatology, Guangzhou Children's Hospital, Guangzhou Medical College, Guangzhou 510120, China.
World J Pediatr. 2008 Aug;4(3):192-6. doi: 10.1007/s12519-008-0035-5.
The arterial partial pressure of carbon dioxide (PaCO2) represents the balance between CO2 production and consumption. Abnormal increase or decrease in PaCO2 can affect the body's internal environment and function. Permissive hypercapnia has aroused more attention as a novel ventilatory therapy. The aim of this study was to elucidate the effects of hypercapnia and hypocapnia on the functions of such neonatal organs as the lung and brain.
The PubMed database was searched with the keywords "hypocapnia", "hypercapnia" and "newborn".
Hypocapnia is a risk factor for potential damage to the central nervous system, such as periventricular leukomalacia, intraventricular hemorrhage, cerebral palsy, cognition developmental disorder, and auditory deficit. Hyperventilation can lessen pulmonary artery hypertension to certain extent, but hypocapnia can aggravate ischemia/reperfusion-induced acute lung injury. Severe hypercapnia can induce intracranial hemorrhage, even consciousness alterations, cataphora, and hyperspasmia. Permissive hypercapnia can improve lung injury caused by diseases of the respiratory system, lessen mechanical ventilation-associated lung injury, reduce the incidence of bronchopulmonary dysplasia and protect against ventilation-induced brain injury. In addition, permissive hypercapnia plays a role in expanding cerebral vessels and increasing cerebral blood flow.
Severe hypercapnia and hypocapnia can cause neonatal brain injury and lung injury. Permissive hypercapnia can increase the survival of neonates with brain injury or respiratory system disease, and lessen the brain injury and lung injury caused by mechanical ventilation. However, the mechanism of permissive hypercapnia needs further exploration to confirm its safety and therapeutic utility.
动脉血二氧化碳分压（PaCO2）代表二氧化碳产生与消耗之间的平衡。PaCO2异常升高或降低会影响机体的内环境和功能。允许性高碳酸血症作为一种新型通气治疗方法已引起更多关注。本研究旨在阐明高碳酸血症和低碳酸血症对新生儿肺和脑等器官功能的影响。
在PubMed数据库中以“低碳酸血症”“高碳酸血症”和“新生儿”为关键词进行检索。
低碳酸血症是潜在中枢神经系统损伤的危险因素，如脑室周围白质软化、脑室内出血、脑瘫、认知发育障碍和听觉缺陷。过度通气可在一定程度上减轻肺动脉高压，但低碳酸血症会加重缺血/再灌注诱导的急性肺损伤。严重高碳酸血症可诱发颅内出血，甚至意识改变、昏迷和抽搐。允许性高碳酸血症可改善呼吸系统疾病所致的肺损伤，减轻机械通气相关肺损伤，降低支气管肺发育不良的发生率，并预防通气诱导的脑损伤。此外，允许性高碳酸血症在扩张脑血管和增加脑血流量方面发挥作用。
严重高碳酸血症和低碳酸血症可导致新生儿脑损伤和肺损伤。允许性高碳酸血症可提高脑损伤或呼吸系统疾病新生儿的存活率，并减轻机械通气所致的脑损伤和肺损伤。然而，允许性高碳酸血症的机制需要进一步探索，以确认其安全性和治疗效用。
