Neonatal Intensive Care Unit, University Hospital of Patras, Rio, Greece.
Department of Pediatrics, Pediatric Respiratory Unit, University Hospital of Patras, Rio, Greece.
Pediatr Pulmonol. 2024 May;59(5):1274-1280. doi: 10.1002/ppul.26899. Epub 2024 Feb 14.
We aimed to assess diaphragmatic function in term and preterm infants with and without history of bronchopulmonary dysplasia (BPD), before and after the application of inspiratory flow resistive loading.
Forty infants of a median (range) gestational age of 34 (25-40) weeks were studied. BPD was defined as supplemental oxygen requirement for >28 days of life. Seventeen infants were term, 17 preterm without history of BPD, and six preterm with a history of BPD. The diaphragmatic pressure-time index (PTIdi) was calculated as the mean to maximum trans-diaphragmatic pressure ratio times the inspiratory duty cycle. The PTI was calculated before and after the application of an inspiratory-flow resistance for 120 s. Airflow was measured by a pneumotachograph and the transdiaphragmatic pressure by a dual pressure catheter.
The median (interquartile range [IQR]) pre-resistance PTIdi was higher in preterm infants without BPD (0.064 [0.050-0.077]) compared with term infants (0.052 [0.044-0.062], p = .029) and was higher in preterm infants with BPD (0.119 [0.086-0.132]) compared with a subgroup of preterm infants without BPD (0.062 [0.056-0.072], p = .004). The median (IQR) postresistance PTIdi was higher in preterm infants without BPD (0.101 [0.084-0.132]) compared with term infants (0.067 [0.055-0.083], p < .001) and was higher in preterm infants with BPD [0.201(0.172-0.272)] compared with the preterm subgroup without BPD (0.091 [0.081-0.108],p = .004). The median (IQR) percentage change of the PTIdi after the application of the resistance was higher in preterm infants without BPD (65 [51-92] %) compared with term infants (34 [20-39] %, p < .001).
Preterm infants, especially those recovering from BPD, are at increased risk of diaphragmatic muscle fatigue under conditions of increased inspiratory loading.
我们旨在评估患有和不患有支气管肺发育不良（BPD）的足月和早产儿的膈肌功能，在应用吸气流量阻力负荷前后。
研究了 40 名中位（范围）胎龄为 34（25-40）周的婴儿。BPD 定义为需要补充氧气>28 天。17 名婴儿为足月，17 名早产儿无 BPD 史，6 名早产儿有 BPD 史。膈肌压力-时间指数（PTIdi）计算为平均最大跨膈肌压力比乘以吸气工作周期。在应用吸气流量阻力 120 秒后，计算 PTI。气流通过气动计测量，跨膈肌压力通过双压力导管测量。
无 BPD 的早产儿的中位（四分位距 [IQR]）预阻力 PTIdi 高于足月婴儿（0.064[0.050-0.077]比 0.052[0.044-0.062]，p=0.029），BPD 的早产儿（0.119[0.086-0.132]）高于无 BPD 的早产儿亚组（0.062[0.056-0.072]，p=0.004）。无 BPD 的早产儿的中位（IQR）后阻力 PTIdi 高于足月婴儿（0.101[0.084-0.132]比 0.067[0.055-0.083]，p<0.001），BPD 的早产儿[0.201（0.172-0.272）]高于无 BPD 的早产儿亚组（0.091[0.081-0.108]，p=0.004）。无 BPD 的早产儿应用阻力后的 PTIdi 中位（IQR）变化百分比高于足月婴儿（65[51-92]%比 34[20-39]%，p<0.001）。
早产儿，特别是从 BPD 中恢复的早产儿，在吸气负荷增加的情况下，膈肌肌肉疲劳的风险增加。
