Neonatal Intensive Care Unit, Policlinico S. Maria alle Scotte, Azienda Ospedaliera Universitaria Senese, Siena, Italy. claudiodefelix @ hotmail.it
Neonatology. 2010 Jun;98(1):18-22. doi: 10.1159/000262482. Epub 2009 Dec 2.
Emerging evidence indicates that hyperoxia is a risk factor for bronchopulmonary dysplasia, a common multifactorial long-term complication of prematurity. To date, the equivalence between set and delivered oxygen (O(2)) in ventilated preterm infants has not been rigorously studied.
To test the hypothesis of systematic underestimation of O(2) delivery in extremely low birth weight (ELBW) infants during long-term ventilation.
Actually achieved O(2) concentrations were measured and compared to the set inspired oxygen fraction (FiO(2)). A total of 108 O(2) measurements were carried out during the ventilation of 54 ELBW infants: O(2)-Delta error (i.e., the difference between O(2) concentrations achieved by the ventilator and set FiO(2)) was the main study outcome measure.
Systematic O(2)-Delta errors were found, with mean values of +9.52% (FiO(2) 0.21-0.40), +2.10 (FiO(2) 0.41-0.60), +2.86% (FiO(2) 0.61-0.80), and +0.016% (FiO(2) 0.81-1.0; p < 0.0001). Theoretical simulations from the observed data indicate that, if not corrected, systematic O2-Delta errors would lead to a non-intentional total O(2) load of 1,202.9 (FiO(2) 0.21-0.40), 252.46 (FiO(2) 0.41-0.60), 342.85 (FiO(2) 0.61-0.80), and 2 (FiO(2) 0.81-1.0) extra liters/kg body weight/100 ventilation hours.
Systematic underestimation of the O(2) delivered by infant ventilators can potentially lead to surprisingly large increases in total O(2) load during long-term ventilation of ELBW infants, especially in the lower FiO(2) range (i.e., 0.21-0.40). Underestimation of true O(2) delivery can potentially lead to unrecognized high O(2) loads, and more pronounced and prolonged hyperoxia.
新出现的证据表明，高氧是支气管肺发育不良的一个危险因素，支气管肺发育不良是早产儿常见的多因素长期并发症。迄今为止，通气早产儿设定和输送的氧气（O(2)）之间的等效性尚未经过严格研究。
检验极低出生体重（ELBW）儿长期通气时系统低估 O(2)输送的假设。
测量实际达到的 O(2)浓度，并与设定的吸入氧分数（FiO(2)）进行比较。在对 54 名 ELBW 婴儿进行通气期间，共进行了 108 次 O(2)测量：O(2)-Delta 误差（即呼吸机实际达到的 O(2)浓度与设定的 FiO(2)之间的差异）是主要的研究结果测量指标。
发现存在系统的 O(2)-Delta 误差，平均值分别为+9.52%（FiO(2)0.21-0.40）、+2.10（FiO(2)0.41-0.60）、+2.86%（FiO(2)0.61-0.80）和+0.016%（FiO(2)0.81-1.0；p<0.0001）。根据观察数据进行的理论模拟表明，如果不进行校正，系统的 O2-Delta 误差将导致非故意的总 O(2)负荷增加 1202.9（FiO(2)0.21-0.40）、252.46（FiO(2)0.41-0.60）、342.85（FiO(2)0.61-0.80）和 2（FiO(2)0.81-1.0）额外升/公斤体重/100 通气小时。
婴儿呼吸机输送的 O(2)被系统低估，这可能导致极低出生体重儿长期通气时总 O(2)负荷显著增加，尤其是在较低的 FiO(2)范围内（即 0.21-0.40）。对真实 O(2)输送的低估可能导致未被识别的高 O(2)负荷，并导致更明显和更持久的高氧血症。
