Intrapulmonary Volume Changes during Hiccups versus Spontaneous Breaths in a Preterm Infant

Rescue nasopharyngeal tube for preterm infants non-responsive to initial ventilation after birth

BACKGROUND

Physiological changes during the insertion of a rescue nasopharyngeal tube (NPT) after birth are unclear.

METHODS

Observational study of very preterm infants in the delivery room. Data were extracted at predefined timepoints starting with first facemask placement after birth until 5 min after insertion of NPT. End-expiratory lung impedance (EELI), heart rate (HR) and SpO2/FiO2-ratio were analysed over time. Changes during the same time span of NIPPV via facemask and NIPPV via NPT were compared.

RESULTS

Overall, 1154 inflations in 15 infants were analysed. After NPT insertion, EELI increased significantly [0.33 AU/kg (0.19-0.57), p < 0.001]. Compared with the mask period, changes in EELI were not significantly larger during the NPT period [median difference (IQR) = 0.14 AU/kg (-0.14-0.53); p = 0.12]. Insertion of the NPT was associated with significant improvement in HR [52 (33-96); p = 0.001] and SpO2/FiO2-ratio [161 (69-169); p < 0.001] not observed during the mask period.

CONCLUSIONS

In very preterm infants non-responsive to initial facemask ventilation after birth, insertion of an NPT resulted in a considerable increase in EELI. This additional gain in lung volume was associated with an immediate improvement in clinical parameters. The use of a NPT may prevent intubation in selected non-responsive infants.

IMPACT

After birth, a nasopharyngeal tube may be considered as a rescue airway in newborn infants non-responsive to initial positive pressure ventilation via facemask. Although it is widely used among clinicians, its effect on lung volumes and physiological parameters remains unclear. Insertion of a rescue NPT resulted in a considerable increase in lung volume but this was not significantly larger than during facemask ventilation. However, insertion of a rescue NPT was associated with a significant and clinically important improvement in heart rate and oxygenation. This study highlights the importance of individual strategies in preterm resuscitation and introduces the NPT as a valid option.

Early prediction of pulmonary outcomes in preterm infants using electrical impedance tomography

Introduction

Electrical impedance tomography (EIT) allows assessment of ventilation and aeration homogeneity which may be associated with respiratory outcomes in preterm infants.

Methods

This was a secondary analysis to a recent randomized controlled trial in very preterm infants in the delivery room (DR). The predictive value of various EIT parameters assessed 30 min after birth on important respiratory outcomes (early intubation <24 h after birth, oxygen dependency at 28 days after birth, and moderate/severe bronchopulmonary dysplasia; BPD) was assessed.

Results

Thirty-two infants were analyzed. A lower percentage of aerated lung volume [OR (95% CI) = 0.8 (0.66-0.98), p = 0.027] as well as a higher aeration homogeneity ratio (i.e., more aeration in the non-gravity-dependent lung) predicted the need for supplemental oxygen at 28 days after birth [9.58 (5.16-17.78), p = 0.0028]. Both variables together had a similar predictive value to a model using known clinical contributors. There was no association with intubation or BPD, where numbers were small.

Discussion

In very preterm infants, EIT markers of aeration at 30 min after birth accurately predicted the need for supplemental oxygen at 28 days after birth but not BPD. EIT-guided individualized optimization of respiratory support in the DR may be possible.