Predicting decline and survival in severe acute brain injury: the fourth trajectory

Three illness trajectories have been proposed to conceptualise how function declines as diseases advance to death: a short decline as with cancer; an episodic decline as with heart failure; and a prolonged decline as with dementia (fig 1 double down arrow).(1 2) These frameworks allow patients, family members, providers, and healthcare planners to prepare for next steps as they confront the limits of modern medicine and to develop compassionate healthcare systems that allow patients to live, age, and die with self respect and grace. None of the existing trajectories is suitable for patients with severe acute brain injury,(3) a distinct group of neurological catastrophes for which the patient and their families are typically unprepared. Examples include vascular brain injury (both focal as with stroke and global as after cardiac arrest); inflammatory brain injury (infectious and non-infectious); and traumatic brain injury. Patients present acutely neurologically devastated and face a trajectory that often results in either early death or a more uncertain prognosis that may resemble the chronic disease trajectory with prolonged dwindling. Although the exact number of patients affected by this heterogeneous group of diseases is unknown, the numbers of deaths worldwide every year from stroke (6.7 million), sudden cardiac arrest (3.7 million), and traumatic brain injury (>1 million) suggest that their contribution to both death and adult disability are large enough to warrant attention. (4-6) Improved emergency response services and advances in acute and critical care management across all of these conditions, are likely to increase the numbers of patients surviving the initial period. Adopting a fourth trajectory for these patients (fig 2 double down arrow) could help prepare providers, patients, and their families to make more informed and critical decisions about care.