EXPERIENCE WITH HIGH FREQUENCY OSCILLATORY VENTILATION IN THE MANAGEMENT OF ADULT SURGICALTRAUMA PAT

1
EXPERIENCE WITH HIGH FREQUENCY OSCILLATORY
VENTILATION IN THE MANAGEMENT OF ADULT
SURGICAL/TRAUMA PATIENTS WITH ARDS Stuart M.
Lowson, MD, Daniel D. Rowley, BS, RRT-NPS, RPFT,
Linda Clarke, RRT, Jeffrey S. Young, MD, Roy
Hostetter, RRT Surgical/Trauma ICU
INTRODUCTION After participating in the
Multicenter Oscillatory Ventilation for Acute
Respiratory Distress Syndrome II (MOAT II) study
1, we hypothesized that early application of HFOV
would improve outcomes in surgical/trauma
patients with ARDS.
RESULTS Of the 17 patients we entered into the
MOAT II trial, 6-month mortality was 50 in CMV
group -vs- 29 in the HFOV group. We have used
HFOV in 65 patients to date. Minor changes in
our management strategies include 1. Earlier
initiation of HFOV when P/F ratios fail to
improve with conventional lung recruitment
strategies. 2. Aggressive use of ?P, increased
It, decreased oscillating frequency, and
maximized BF (50-60 LPM) to optimize ventilation.
3. Earlier discontinuation of NMBs and
scrupulous titration of sedation to permit
patient tolerance of HFOV. Our current 28-day
mortality in surgical/trauma patients with ARDS,
using the above approach, is 20 (30 day
mortality in the ARDS Network trials low Vt
group was 312).
METHOD We identified patients at risk of
ALI/ARDS by the following criteria chest trauma,
gt 10L of initial volume resuscitation, developing
infiltrates on roentgenograms, P/F ratio lt 200
mmHg, and airway Pplateau gt 30 cmH20 despite
using low Vts. Patients were sedated,
administered a neuromuscular blocking (NMB)
agent, and placed on HFOV (SensorMedics 3100B).
Initial FIO2 is set at 100, frequency 3 Hz,
It 50, MAP 5-8 cmH2O gt CMV level, Bias Flow
(BF) 50-60 LPM, and Delta-P (?P) is set to
achieve adequate chest wall wiggle. Our goals
of HFOV are to obtain an arterial pH 7.25, SaO2
90, and FIO2 50 at the lowest MAP.
Patients are returned to CMV when MAP is lt 22
cmH2O or if HFOV fails to achieve adequate
ventilation.
CONCLUSION The open lung model of ARDS
management strongly suggests that HFOV should be
an effective technique to use in this patient
population. This hypothesis is supported by the
results of HFOV in animal models of ARDS, and by
our outcome data in both the MOAT II study and
surgical/trauma patients with ARDS. Studies by
Gattinoni and others suggest that patients with
secondary lung injury may respond better to
recruitment maneuvers vs- those patients with
primary lung injury.3 This may partly explain
why our 6 month mortality rate with HFOV in the
Moat II study was less than that of the study
population as a whole (47 with HFOV).
REFERENCES 1.Derdak, S, Mehta S, Stewart T, et
al. High frequency oscillatory ventilation for
acute respiratory distress syndrome in adults. Am
J Resp Crit Care Med 2002166801-8. 2.The Acute
Respiratory Distress Syndrome Network.
Ventilation with lower tidal volumes as compared
with traditional tidal volumes for acute lung
injury and the acute respiratory distress
syndrome. N Eng J Med 20003421301-8. 3.
Gattinoni L, Pelosi P, Suter P, et al. Acute
respiratory distress syndrome caused by pulmonary
and extrapulmonary disease. Different syndromes?
Am J Resp Crit Care Med 1998 1583-11.