Acute respiratory distress syndrome in traumatic brain injury: how do we manage it?

Abstract

Traumatic brain injury (TBI) is an important cause of morbidity and mortality worldwide. TBI patients frequently suffer from lung complications and acute respiratory distress syndrome (ARDS), which is associated with poor clinical outcomes. Moreover, the association between TBI and ARDS in trauma patients is well recognized. Mechanical ventilation of patients with a concomitance of acute brain injury and lung injury can present significant challenges. Frequently, guidelines recommending management strategies for patients with traumatic brain injuries come into conflict with what is now considered best ventilator practice. In this review, we will explore the strategies of the best practice in the ventilatory management of patients with ARDS and TBI, concentrating on those areas in which a conflict exists. We will discuss the use of ventilator strategies such as protective ventilation, high positive end expiratory pressure (PEEP), prone position, recruitment maneuvers (RMs), as well as techniques which at present are used for 'rescue' in ARDS (including extracorporeal membrane oxygenation) in patients with TBI. Furthermore, general principles of fluid, haemodynamic and hemoglobin management will be discussed. Currently, there are inadequate data addressing the safety or efficacy of ventilator strategies used in ARDS in adult patients with TBI. At present, choice of ventilator rescue strategies is best decided on a case-by-case basis in conjunction with local expertise.

Keywords: Traumatic brain injury (TBI); acute respiratory distress syndrome (ARDS); extra corporeal membrane oxygenation (ECMO); positive end expiratory pressure (PEEP).

Figure 1

Computed tomography (left panel), and chest X-ray (right side) of a patient with ARDS.

Figure 2

Computed tomography in two patients with traumatic brain injury (TBI). (A) diffuse brain swelling with traumatic subarachnoidal haemorrage; (B) devastating traumatic brain injury with multiple intracerebral haemorrages after decompressive craniectomy.

Figure 3

Invasive (through ICP Bolt) and non invasive ICP (through optic nerve sheath diameter) monitoring in a patient with TBI and ARDS during recruitment manoeuvres and increased levels of PEEP. Initially, ICP is below 20 mmHg (mean ONSD =5.2), with PEEP =8, with stable arterial blood pressure (ABP) and cerebral perfusion pressure (CPP). After recruitment manoeuvres and setting PEEP at 16, ICP spikes up >20 mmHg, with ABP and CPP increase (ONSD =7 mm). PaCO₂ remained constant during the procedure and the patients remained haemodynamically stable.