Lazić Zorica, Cekerevac Ivan, Novković Ljiljana, Cupurdija Vojislav
Klinicki centar, Centar za plućne bolesti, Interna klinika, Kragujevac, Srbija.
Vojnosanit Pregl. 2008 Jul;65(7):521-4. doi: 10.2298/vsp0807521l.
BACKGROUND/AIM: Oxygen therapy is a necessary therapeutic method in treatment of severe chronic respiratory failure (CRF), especially in phases of acute worsening. Risks which are to be taken into consideration during this therapy are: unpredictable increase of carbon dioxide in blood, carbonarcosis, respiratory acidosis and coma. The aim of this study was to show the influence of oxygen therapy on changes of arterial blood carbon dioxide partial pressure.
The study included 93 patients in 104 admittances to the hospital due to acute exacerbation of CFR. The majority of the patients (89.4%) had chronic obstructive pulmonary disease (COPD), while other causes of respiratory failure were less common. The effect of oxygenation was controlled through measurement of PaO2 and PaCO2 in arterial blood samples. To analyse the influence of oxygen therapy on levels of carbon dioxide, greatest values of change of PaO2 and PaCO2 values from these measurements, including corresponding PaO2 values from the same blood analysis were taken.
The obtained results show that oxygen therapy led to the increase of PaO2 but also to the increase of PaCO2. The average increase of PaO2 for the whole group of patients was 2.42 kPa, and the average increase of PaCO2 was 1.69 kPa. There was no correlation between the initial values of PaO2 and PaCO2 and changes of PaCO2 during the oxygen therapy. Also, no correlation between the produced increase in PaO2 and change in PaCO2 during this therapy was found.
Controlled oxygen therapy in patients with severe respiratory failure greately reduces the risk of unwanted increase of PaCO2, but does not exclude it completely. The initial values of PaO2 and PaCO2 are not reliable parameters which could predict the response to oxygen therapy.
背景/目的：氧疗是治疗重度慢性呼吸衰竭（CRF）的必要治疗方法，尤其是在急性加重期。该治疗过程中需考虑的风险包括：血液中二氧化碳不可预测的增加、二氧化碳麻醉、呼吸性酸中毒和昏迷。本研究的目的是显示氧疗对动脉血二氧化碳分压变化的影响。
本研究纳入了93例因CRF急性加重而住院104次的患者。大多数患者（89.4%）患有慢性阻塞性肺疾病（COPD），而其他呼吸衰竭原因则较少见。通过测量动脉血样本中的PaO2和PaCO2来控制氧合效果。为分析氧疗对二氧化碳水平的影响，取这些测量中PaO2和PaCO2值变化的最大值，包括同一血液分析中相应的PaO2值。
所得结果表明，氧疗导致PaO2升高，但也导致PaCO2升高。整个患者组的PaO2平均升高2.42 kPa，PaCO2平均升高1.69 kPa。氧疗期间PaO2和PaCO2的初始值与PaCO2的变化之间无相关性。此外，在该治疗过程中，PaO2的升高与PaCO2的变化之间也未发现相关性。
对重度呼吸衰竭患者进行控制性氧疗可大大降低PaCO2意外升高的风险，但不能完全排除这种情况。PaO2和PaCO2的初始值不是可预测对氧疗反应的可靠参数。
