INTENSIVE CARE

Table 1. Summary of Blood Gas in conjunction with Interventions.
cbg abg Abg Abg Abg Abg Abg cbg cbg cbg
Age 0 hrs 12 hrs DOL 2 DOL 3 DOL6 DOL 7 DOL 9 DOL 12 DOL 18 DOL 31
pH 7.19/ 7.30 7.25 7.26 7.41 7.39 7.387 7.387 7.369 7.34
PCO2 (mmHg) 78 42 57 59 50 48 55 52 60 51
pO2
(mmHG)
57 118 66 52 92 70 62 57 48 58
Bicarb 29.7 20.0 23.5 26.0 30.8 28.2 32 31 34 27
Base Excess -1.0 -5.7 -3.8 -1.8 5.4 3.0 6 4.8 6.9 1.2
Intervention: iNO started Switch to
HFOV
Max settings
HFOV
Steroids
Started
Weaning
iNO
Conv. Vent Post ext iNO Off Ncpap RA
Echocardiogram was completed at 12 hours of life and summary
showed evidence of PPHN with bidirectional shunting through
the PDA, right ventricular hypertrophy with right ventricular
dilation flattened ventricular septum, and tricuspid regurgitation
with estimated mean PA pressure at 65 mmHg. Systemic Blood
Pressure was 63/48 mmHg with a mean of 53.
HFOV settings were: MAP (mean airway pressure) 17 cmH2O,
Amplitude 40, Hz 10, Inspiratory time 33%, Bias Flow 15 Lpm.
OI is +25. After a discussion with pediatric cardiology to discuss
the echo findings, inhaled nitric oxide was started in line with
the conventional ventilator, at 20 ppm. Difference between pre
and post ductal oximeters was 3% prior to intiating inhaled nitric
oxide. Infant also presents with relative hypotension requiring
two boluses of normal saline and a Dopamine drip.
Seven hours after starting iNO, the PaO2 climbed to 118 on ABG
(7.30/pCO2 42 mmHg /PaO2 118 mmHg /20.0 mmol/L/-5.7 (base
excess)). The Oxygen Index improved to 11.5 with ventilator
settings: PIP: 28 cmH2O, PEEP: 7 cmH2O, inspiratory time: 0.35
seconds, 50 breaths per minute, pressure support: 10 cmH2O, but
FiO2 remained around 0.80.
At 24 hours of life, despite iNO and increased ventilator settings,
FiO2 requirements was greater than 0.80. Nebulizers were
started in line with the ventilator for secretion management.
(Aerogen was placed on the inlet to the heater chamber, below
the injector module; the sample line filter was changed every
four hours to protect the iNO system monitor from aerosol
contamination). Albuterol (2.5MG/3ML) was ordered at a
dose of 1.25 mg every 12 hours. The Albuterol was mixed with
hypertonic with Sodium Chloride 7% at a dose of 1.1 ml (we
added 0.4 ml sterile water + 3% NaCl neb with 1.25 mg albuterol).
Due to worsening secretions nebulizer frequency was increased
to every 6 hour.
Over the next 24 hours the FiO2 was weaned to 0.57. However,
ventilator settings remained high. The highest conventional
settings recorded were: Assist Control Mode, 50 breaths per
minute, PIP: 30 cmH2O, PEEP: 7 cmH2O, Inspiratory time 0.32
seconds. Despite these significant settings the PaCO 2 remained
in the mid-50s mmHg. Physician’s goal was to achieve PaCO 2
around 40 mmHg. OI ranged from 12-15.6.
At two days of age, the infant had an episode requiring manual
ventilation using high peak airway pressures. SpO2 dropped into
the low 40s. Recovery was very slow. Following this event an
ABG showed PaCO2 increasing to 57mmHg PaO2 66 mmHg, pH
7.25, 23.5 mmol/L, -3.8 (base excess). iNO was continued at 20
ppm and the infant was switched to high frequency oscillatory
ventilation (HFOV). Nebulizers were held while on HFOV. Initial
DOL 2: Slightly worsened bilateral predominantly central patchy opacities,
which may represent a combination of superimposed worsened atelectasis
and central vascular congestion.
Echocardiogram was repeated at two days of age. There was
evidence of severe pulmonary artery hypertension, no PDA,
patent foramen ovale, mainly left to right with normal pulmonary
venous return, dilated hypertrophied right ventricle, and with
mildly decrease LV systolic function.
Over the next 12 hours HFOV settings continuously increased
reaching a maximum of: Mean Airway Pressure 20 cmH2O,
Amplitude 52, Hertz 9, Bias flow 20 Lpm, and FiO2 of 1.00. OI is
greatly elevated at 38.5. ABG showed 7.26/pCO2 59 mmHg /PaO2
52 mmHg /26.0 mmol/L/-1.8 (base excess). The baby remained
on Dopamine. Total fluids were increased due to concern for
intravascular volume depletion with high HFOV limiting venous
return.
At this time there was a family conference to discuss two
possible options: a transfer to an ECMO center including the risk
associated with transporting the infant and the actual risks of
ECMO, or starting systemic steroids which have their own risks.
The family and hospital team chose to start the glucocorticoid
dexamethasone due to ventilator failure, severe secretions, and
bradycardia/desaturation events.
At three days of age, dexamethasone was started at 0.1 mg/kg IV,
Q6 hours, to reduce lung inflammation.
neonatal INTENSIVE CARE Vol. 29 No. 4 • Fall 2016 29