Airway obstruction is a cause of apnea in preterm infants. The activity of protective respiratory reflexes was determined in 18 preterm infants with apnea (mean of 32 episodes of more than 20 seconds duration per day) and in 18 neonates without apnea used as control subjects. This was done in order to elucidate the role of respiratory reflexes in apnea of prematurity. The infants were matched for birth weight (1,068 g v 1,065 g), gestational age (30.2 weeks v 30.2 weeks), and postnatal age (8.6 days v 8.3 days). The airway occlusion technique was used to determine the inspiratory prolongation of the occluded breath and the effective elastance of the respiratory system. Inspiratory prolongation is a measure for the reflex influence on inspiratory duration, and effective elastance reflects load compensating ability. Inspiratory prolongation was 7.3% ± 33.5% in infants with apnea and 30.6% ± 22.7% in the control group ( P .025). Effective elastance was 1.1 ± 0.5 cm H2O/mL in the apneic group and 1.5 ± 0.5 cm H2O/mL in the infants without apnea ( P .025). The results indicate that during exposure to respiratory loads, the infants with apnea maintained inspiratory effort poorly and had a decreased ability for load compensation. Their respiratory reflexes were significantly more immature than the reflex activity of the infants without apnea. This functional immaturity of respiratory reflexes may be a contributing factor in the etiology of apnea of prematurity.
展开▼
机译：气道阻塞是早产儿呼吸暂停的原因。在18名患有呼吸暂停的早产儿（平均每天持续超过20秒的32次发作）和18例无呼吸暂停的新生儿中，确定了保护性呼吸反射的活动。这样做是为了阐明呼吸反射在早产呼吸暂停中的作用。对婴儿的出生体重（1,068 g v 1,065 g），胎龄（30.2周v 30.2周）和产后年龄（8.6天v 8.3天）进行匹配。气道阻塞技术用于确定阻塞性呼吸的吸气时间延长和呼吸系统的有效弹性。吸气时间延长是反射对吸气时间影响的一种量度，有效弹性反映了负荷补偿能力。呼吸暂停婴儿的吸气时间延长为7.3％±33.5％，对照组为30.6％±22.7％（P <.025）。窒息组的有效弹性为1.1±0.5 cm H2O / mL，无呼吸暂停的婴儿为1.5±0.5 cm H2O / mL（P <.025）。结果表明，在暴露于呼吸负荷的过程中，呼吸暂停婴儿的吸气力维持较差，负荷补偿能力下降。他们的呼吸反射比没有呼吸暂停的婴儿的反射活动还明显不成熟。呼吸反射的这种功能不成熟可能是早产呼吸暂停的病因学中的一个促成因素。
展开▼
