Bronchopulmonary dysplasia and carbon dioxide retention.

AIM: The aim of this study was to determine the pre-discharge carbon dioxide (CO2 ) levels of preterm neonates with bronchopulmonary dysplasia (BPD) requiring ongoing nasal cannulae oxygen therapy and who were ready for discharge home. METHODS: We studied a retrospective cohort of infants born <30 weeks gestational age (GA) at ≥36 weeks corrected GA who had established BPD requiring ongoing nasal cannulae oxygen therapy and were ready for discharge home. Neonates were born and admitted between May 2014 and December 2018. Demographic data at the time of birth and at the time of the last blood gas sampled were collected. RESULTS: One hundred five neonates had median GA of 26.1 weeks and birth weight of 775 g. Median (IQR) CO2 level was 54 (49-58) mmHg. Ninety-nine (94%) neonates had CO2 levels exceeding the normal range and 91 (87%) neonates had a CO2 between 45 and 65 mmHg. CONCLUSION: Ninety-four per cent of neonates <30 weeks GA at ≥36 weeks corrected GA requiring ongoing nasal cannulae oxygen therapy for established BPD, who were ready for discharge home, have CO2 levels outside of normocapnia (35-45 mmHg), with 87% having CO2 levels between 45 and 65 mmHg.

Factors associated with successful extubation following the first course of systemic dexamethasone in ventilator-dependent preterm infants with or at risk of developing bronchopulmonary dysplasia.

OBJECTIVES: We aimed to identify factors present at the start of an initial course of systemic dexamethasone that would be associated with successful extubation in mechanically ventilated neonates <30 weeks gestational age (GA) with or at risk of developing bronchopulmonary dysplasia (BPD). METHODS: We studied a retrospective cohort of neonates (23+0 -29+6 weeks GA), with or at risk of developing BPD, prescribed their first course of systemic dexamethasone to aid in extubation from mechanical ventilation. The data collected only pertained to the first course of dexamethasone. Neonates given dexamethasone for airway edema were not included. The primary outcome of interest was successful extubation (i.e., extubated within 14 days of starting dexamethasone and remaining extubated for at least 7 days). Binary logistic regression was employed. RESULTS: A total of 287 neonates were included. Each additional week of GA at birth led to a 1.53 increase in the odds of successful extubation (95% CI: 1.122-2.096, p < 0.01). Higher average fraction of inspired oxygen (FiO2 ) requirements in the preceding 24 h resulted in a 0.94 decrease in the odds of successful extubation (p < 0.05) and higher mean airway pressure (MAP) resulted in 0.76 decrease in odds of successful extubation (p < 0.01). CONCLUSIONS: Mechanically ventilated neonates with or at risk of developing BPD, born at <30 week GA and initiated on dexamethasone to facilitate extubation, had a lower likelihood of successful extubation by Day 14 if they had younger GA at birth, and at the time of commencing steroids had higher MAPs and had higher oxygen requirements.

Ventilation settings in preterm neonates with ventilator-dependant, evolving bronchopulmonary dysplasia.

OBJECTIVE: The only guidance in the literature on which tidal volumes to use when ventilating babies with, or at high risk of, bronchopulmonary dysplasia (BPD) suggests using very large volume breaths of around 8-12 mL/kg and low rates (10-20 breaths per min) to achieve adequate gas exchange, whilst acknowledging there are no data to validate these strategies. The aim of this retrospective, observational, cohort study was to identify the mechanical ventilation settings that are used, and what carbon dioxide (CO2) levels were achieved, in neonates with ventilator-dependant evolving BPD. METHODS: This retrospective cohort study included neonates born <30 weeks GA admitted to the Grantley Stable Neonatal Unit between May 2014 and December 2018. Included ventilator-dependant neonates with evolving BPD ventilated on either or all days 28, 42 and 56 of life. RESULTS: A total of 105 neonates were included, all were between 23 and 28.5 weeks GA. The median (IQR) GA was 25.1 (24.2-26.5) weeks and BW 708 (608-809) grams. Neonates who required conventional mechanical ventilation (CMV) at each of the three time-points had median tidal volumes ranging between 4.5 and 4.7 mL/kg, median ventilator rates of 35-50 and MAPs of 10-11 cmH2O. For those neonates requiring HFOV, median MAPs ranged from 14 to 18 cmH2O and tidal volumes from 1.4 to 2.2 mL/kg to achieve adequate ventilation and oxygenation. CONCLUSIONS: Neonates with ventilator-dependant evolving BPD were ventilated either with CMV using tidal volumes of around 4-5 mL/kg, or HFOV using tidal volumes around 1-2 mL/kg, which achieves adequate ventilation and blood gas results.