Extracorporeal decarboxylation in patients with severe traumatic brain injury and ARDS enables effective control of intracranial pressure
Care 2015, 19:381
Munoz-Bendix, c. et al
respiratory distress syndrome (ARDS) with concomitant impairment of oxygenation
and decarboxylation represents a complex problem in patients with increased
intracranial pressure (ICP). Permissive hypercapnia is not an option to obtain
and maintain lung-protective ventilation in the presence of elevated ICP.
Pumpless extracorporeal lung assist (pECLA) devices (iLA Membrane Ventilator;
Novalung, Heilbronn, Germany) can improve decarboxylation without aggravation
associated with invasive ventilation. In this pilot series, we analyzed the
safety and efficacy of pECLA in patients with ARDS and elevated ICP after severe
traumatic brain injury (TBI).
Methods: The medical records of ten patients
(eight male, two female) with severe ARDS and severe TBI concurrently managed
with external ventricular drainage in the neurointensive care unit (NICU) were
retrospectively analyzed. The effect of pECLA on enabling lung-protective
ventilation was evaluated using the difference between plateau pressure and
positive end-expiratory pressure, defined as driving pressure (ΔP), during the
3 days preceding the implant of pECLA devices until 3 days afterward. The ICP
threshold was set at 20 mmHg. To evaluate effects on ICP, the volume of daily
cerebrospinal fluid (CSF) drainage needed to maintain the set ICP threshold was
compared pre- and postimplant.
Results: The ΔP values after pECLA implantation
decreased from a mean 17.1 ± 0.7 cm/H 2 O to 11.9±0.5 cm/H 2 O (p = 0.011). In
spite of this improved lung-protective ventilation, carbon dioxide pressure
decreased from 46.6 ± 3.9 mmHg to 39.7 ± 3.5 mmHg (p = 0.005). The volume of
daily CSF drainage needed to maintain ICP at 20 mmHg decreased significantly
from 141.5 ± 103.5 ml to 62.2 ± 68.1 ml (p = 0.037). Conclusions: For selected
patients with concomitant severe TBI and ARDS, the application of pECLA is safe
and effective. pECLA devices improve decarboxylation, thus enabling
lung-protective ventilation. At the same time, potentially detrimental
hypercapnia that may increase ICP is avoided. Larger prospective trials are
warranted to further elucidate application of pECLA devices in NICU patients.