Rescue of Term Infant with Refractory Airleak Using High-Frequency
Jet Ventilation
Steve Greubel, RRT, St. Mary's Medical Center, Evansville IN.
Baby boy J was a term 3450 gram male born to a 35 year old who was gravida
5, para 2. He was born by C-section at an outlying hospital with APGARS of
9 and 10 at one and five minutes respectively. Baby J developed respiratory
distress shortly after birth and his oxygen requirement increased to 70%.
In spite of the increased oxygen he remained tachypneic and was transferred
to St. Mary's Medical Center for evaluation and treatment.
Shortly after admission an echocardiogram revealed suprasystemic pulmonary
artery pressures, evidence of moderate to sever pulmonary hypertension. Chest
x-ray showed bilateral atelectasis and consolidation. The infant was intubated
and placed on mechanical ventilation at a Rate of 60 bpm, PIP of 25 cm H2O,
PEEP of 5 cm H2O, I-time of 0.37 sec. with
a MAP of 15 cm H2O. While on conventional
ventilation he was given 8 ml of Survanta®. At the end of one hour Baby
J was still requiring 100% oxygen. The decision was made to switch him to
HFOV (SensorMedics 3100A) at a frequency of 10 Hz, amplitude of 32 cm H2O,
MAP of 16 cm H2O. He was started on Dopamine
at 5 mcg/kg/min and transfused with fresh frozen plasma due to poor perfusion.
He was also sedated with Morphine and Phenobarb due to prolonged irritability.
The first ABG on HFOV at 40% oxygen was PO2
64, PCO2 36, pH 7.42 and HCO3
23.
By the afternoon of day two Baby J had been weaned to 25% oxygen on a MAP
of 18 cm H2O and was reasonably stable.
Then his oxygen saturation began to fall suddenly and the FiO2
had to be increased to 0.45. A stat chest x-ray revealed a right pneumothorax,
which required the placement of a thoracotomy tube. Following the procedure
the HFOV MAP was increased to 22 cm H2O
and the amplitude was raised from 30 to 34 cm H2O.
He also received another transfusion of plasma, at this time, to stabilize
his blood pressure. Due to increasing oxygen requirements and growing difficulty
managing his cardio respiratory status, Baby J received a second dose of Survanta
and was paralyzed using Pavulon.
On the morning of day four, HFOV settings were frequency of 10 Hz, amplitude
of 34 cm H2O, MAP of 16 cm H2O
and oxygen of 46%. Capillary gases were PO2
60, PCO2 73, pH 7.28 and HCO3
33. A chest x-ray showed a re-accumulation of the right pneumothorax. After
several unsuccessful attempts to reposition the thoracotomy tube, it was determined
that it was occluded and it was replaced. Deep tracheal suctioning was also
performed that produced a significant amount of clear mucus. Baby J remained
on HFOV and attempts were made to optimize the settings in lieu of the pneumothorax
and high PCO2. When the amplitude was increased
to lower the PCO2 the chest tube activity
would increase and when the amplitude was lowered to limit chest tube activity
the PCO2 would increase. As a result, the
decision was made to initiate a trial of high-frequency jet ventilation using
the Bunnell Life Pulse™. Ventilating effectively at a lower peak and mean
airway pressure, might give the pneumo a chance to resolve.
The Jet was started at 420 bpm, PIP 24 cm H2O,
PEEP of 5 cm H2O, FiO2
of 0.50 with the conventional vent set on a background rate of 6 bpm. These
settings produced a MAP of 9.8 cm H2O, significantly
lower than the MAP of 16 cm H2O on HFOV.
The first capillary blood gas results were PO2
55, PCO2 42, pH 7.49 and HCO3
32. The chest x-ray showed slight under-expansion so PEEP was increased to
6 cm H2O. Baby J slowly improved during
the night and his oxygen was weaned to 30%. The AM chest film showed extensive
clearing with even aeration and no free air. Capillary blood gases were PO2
48, PCO2 46, pH 7.44 and HCO3
31.
During the next several hours Baby J was weaned back to conventional ventilation,
which he tolerated well. He continued to wean that day and by the morning
of day six he was on CPAP. By mid-day he was extubated and that same evening
his chest tube was removed. Baby J had no further cardio respiratory distress
or other problems during the remainder of his hospitalization.
Life Pulse is a trademark of Bunnell, Inc.
Survanta is a trademark of Abbott Laboratories.
