Case 1
The patient was a 0-day-old male neonate with left isolated CDH. The diagnosis of CDH was made prenatally, and 46, XY, der(21)t(1;21)(q42.3;q22.2) was diagnosed via examination using the amniotic fluid. Fetal ultrasonic testing showed a lung thorax transverse area (LT) ratio of 0.10. He was born at full term, 38 weeks and 2 days, through vaginal delivery in the delivery room. The birth weight was 2105 g. After birth, intubation (uncuffed endotracheal tube, 3.5 mm, Smiths Medical, USA) was performed immediately. After admission to the neonatal intensive care unit (NICU), the piston HFOV (calliope-alpha, Metran, Japan) was started as the initial ventilation. At the initial settings, the MAP was 14 cmH2O, the stroke volume (SV) 20 ml, and the frequency 12 Hz. Inhaled nitric monoxide (iNO) was used at 20 ppm because of the persistent pulmonary hypertension of the newborn (PPHN) (Fig. 1). Fourteen hours after birth, PPHN increased and Lipo-prostaglandin E1 (Lipo-PGE1) was administered to keep the arterial duct open and maintain blood flow to the pulmonary artery. After administration of Lipo-PGE1, the level of saturation was increased both pre-ductally and post-ductally, and the saturation was kept around 95% for the next 30 h. The level of saturation decreased, and the dissociation of pre-ductal and post-ductal saturation re-occurred 44 h after birth. Increasing the iNO concentration and MAP was ineffective. Blood gas analysis revealed an alveolar-arterial oxygen difference (AaDO2) of 500 Torr, and oxygenation index (OI) of 20. The PaO2/FiO2 (P/F) ratio was 58.8 (Fig. 3a–c), which required considering the introduction of extra-corporeal membrane oxygenation (ECMO) to save the patient’s life. Before introducing the ECMO, we inspected the pulmonary function tests results. The static pulmonary function was measured by occlusion method using ARFEL III (Aivision, Japan), which adapted a Fleischer type of pneumotachograph. Because under HFOV, pulmonary function tests cannot be performed accurately, we changed ventilator mode from HFOV to CMV, and used muscle relaxant to rule out the effects of spontaneous breathing just before running the test. The occlusion valve operation was measured with 4–5 breaths to confirm reproducibility. The respiratory-system compliance (Crs) level was 0.29 ml/cmH2O/kg and the respiratory-system resistance (Rrs) level was 515 cmH2O·kg/L/s. Because the Rrs level was elevated, we made the decision to shift the ventilator mode from HFOV to CMV at the ventilator settings of PIP 20 cmH2O, PEEP 5 cmH2O, and ventilator rate of 40/min. After switching to CMV, the patient’s heart rate rose from 159 bpm to 169 bpm, and saturation rose from 89 to 96% immediately. Thirty minutes after switching to CMV, blood gas tests revealed that the AaDO2 dropped to 275 and the OI to 7.3, while the P/F ratio increased (Fig. 3a–c). At 55 h after birth, the operation for repairing the diaphragm was performed. The patient was then discharged from our hospital at 1 month of age with an uneventful course of treatment.
Case 2
The patient was a 0-year-old male neonate with left isolated CDH. The diagnosis of CDH was made prenatally. Fetal ultrasonic testing showed a LT ratio of 0.16. The liver was not in the thoracic cavity, and the stomach was in the abdomen. He was born at full term, 39 weeks and 5 days, through caesarean section. The birth weight was 3145 g. After birth, intubation (uncuffed endotracheal tube, 3.5 mm, Smiths Medical, USA) was performed immediately, and piston HFOV (calliope-alpha, Metran, Japan) was started as the initial ventilation method. The patient’s MAP was 15 cmH2O, SV 35 ml, and frequency 12 Hz for the initial settings. iNO was used at 20 ppm due to PPHN (Fig. 2). The level of saturation gradually rose to 98%. Facial features suggested Pallister-Killian syndrome, and a chromosome test revealed mos 47, der(12)(pter→q10)[13]/46, XY[17]). At 30 h after birth, the level of post-ductal saturation decreased to 85% and dissociation of pre-ductal and post-ductal saturation occurred. Increasing iNO and alkalizing was ineffective. Blood gas analysis showed an AaDO2 of 608 Torr, and an OI of 32. The F/P ratio was 45, which indicated the introduction of ECMO (Fig. 3a–c). Pulmonary function tests at this time revealed that the level of Crs was 0.26 ml/cmH2O/kg, and Rrs was 403 cmH2O·kg/L/s. The level of Rrs was clearly rising, thus, we decided to switch the ventilator mode from HFOV to CMV at the ventilator settings of PIP 25 cmH2O, PEEP 5 cmH2O, and ventilator rate of 40/min. After switching the mode, the heart rate rose from 97 bpm to 160 bpm and post-ductal saturation rose from 92 to 97% immediately. Thirty minutes after switching to CMV, blood gas showed that AaDO2 dropped to 339 Torr, and OI dropped to 6.4, while the P/F ratio rose (Fig. 3a–c). Five days after birth, the diaphragm was repaired via a surgical procedure. The patient was then discharged from our hospital at the age of 2 months with an uneventful course of treatment.