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EARLY INTERVENTION WITH HFOV
AND APRV FOR A PEDIATRIC PATIENT WITH ASPIRATION PNEUMONITIS: A CASE STUDY.
Roberta L. Hales BS, RRT, RN,
Suzanne M. Durning BS, RRT, Karen Bonn AS, CRT, Vinay Nadkarni MD; The Children?s
Hospital of Philadelphia, Philadelphia, PA
A 9-month s/p 30-week premature infant
presented with fever, vomiting, diarrhea and circulatory shock. He required
volume resuscitation and tracheal intubation in the emergency department. He
was noted to have formula beneath the vocal cords on tracheal intubation with
a 4.0 uncuffed tracheal tube. Twenty four hours later, the patient was supported
with a Siemens Servo 300, Pressure Regulated Volume Control (PRVC), FiO2 35-50%, Vt 100, RR 25, PEEP 6cmH20, Ti .75 seconds and a peak inflating
pressure of 38-41 cmH20. He was on a pancuronium and fentanyl infusion,
with intermittent lorazepam sedation and managed with permissive hypercapnea
target of PCO2 50-60 torr. In addition, he required 10 mcg/kg/min
dopamine, crystalloid boluses, and 10 ml/kg PRBC?s in a 24-hour period to treat
low blood pressure/hypoperfusion. CXR was consistent with aspiration pneumonitis
and ARDS. During the course of the day, the patient had an increasing oxygen
and ventilation requirement. He was ventilated using a protective lung strategy
of 6ml/kg Vt to limit the peak inflating pressure to 35 cmH2O. PEEP
maneuvers determined a best PEEP of 10 cmH2O.
Blood gas
results were as follows:
| PRVC Settings |
pH |
PCO2 |
PaO2 |
HCO3 |
B.E. |
SpO2 |
| Vt 100ml,
RR 25, PEEP 6cmH2O, FiO2 1.00, PIP 38-41 cmH2O |
7.24 |
62 |
84 |
25.6 |
-3.0 |
94 |
| Vt 85ml, RR
22, PEEP 10 cmH2O, FiO2 .35, PIP 35-37 cmH2O |
7.15 |
83 |
70 |
28.4 |
-2.8 |
89 |
| Vt 85ml, RR
28, Peep 10 cmH2O, FiO2 35, PIP 35-37 cmH2O |
7.32 |
65 |
83 |
34 |
+7 |
90 |
Despite the ability to achieve acceptable
blood gases on conventional ventilation, we transitioned the patient to the
Sensormedic HFOV 3100A, as an early intervention, rather than a rescue strategy.
This decision was made in anticipation of the need for increasing ventilatory
support and V/Q mismatching, in an attempt to minimize iatrogenic lung injury.
| HFOV settings |
pH |
PCO2 |
PaO2 |
HCO3 |
B.E. |
SpO2 |
| Paw 25, Delta
P 55 cmH2O, Frequency 7 Hz, FiO2 .40, Ti 33% |
7.30 |
73 |
81 |
36 |
+8 |
94% |
| Paw 25, Delta
P 55 cmH2O, Frequency 6 Hz, FiO2 .40, Ti 33% |
7.44 |
53 |
114 |
34.7 |
9.1 |
95% |
Blood gas results on the HFOV were
as follows:
The patient was maintained paralyzed
and sedated on the Sensormedic HFOV for four days and subsequently transitioned
to the Drager Evita 4 in APRV, Phigh 35, Plow 12, Thigh 2.5 seconds, Tlow 1.5 seconds. Following transition to APRV, paralysis
was discontinued.
| APRV settings |
pH |
PCO2 |
PaO2 |
HCO3 |
B.E. |
SpO2 |
| Phigh 35, Plow 12,Thigh 2sec.,Tlow 1 sec,FiO2 .45,Vtexh 110ml |
7.38 |
49 |
111 |
29 |
3.3 |
100 |
| Phigh 35,Plow 12, Thigh 2sec, Tlow 1 sec, FiO2.25,
Vtexh 140 ml |
7.56 |
30 |
104 |
26 |
4.6 |
100 |
| Phigh 30, Plow 12,Thigh 2 sec,Tlow 1sec, FiO2 .25 Vtexh 120 ml |
7.50 |
34 |
121 |
27 |
4.3 |
100 |
| Phigh 26, Plow 9 Thigh 2 sec, Tlow 1sec,
FiO2 .30, Vtexh 100 ml |
7.48 |
42 |
122 |
30 |
5.8 |
100 |
| Phigh 24 , Plow 9, Thigh 2sec, Tlow 1 sec, FiO2.30,
Vtexh 98 ml |
7.42 |
46 |
140 |
29 |
4.4 |
100 |
Blood gas results were as follows:
The patient was transitioned to
SIMV with AutoFlow per physician preference and subsequently weaned to extubation
in three days. The patient was weaned from oxygen one day following extubation.
Discussion: Many strategies
can minimize iatrogenic lung injury associated with aspiration pneumonitis and
ARDS. Early intervention with alternative modes of ventilation (HFOV and APRV)
can be effective. HFOV with paralysis/sedation facilitates lung recruitment
and early transition to APRV allows return to spontaneous ventilation without
paralysis and derecruitment of alveoli. This ventilatory strategy resulted in
a positive patient outcome and may be a useful management strategy.
OF-02-165
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