Pulmonary complications of aneurysmal subarachnoid hemorrhage

Pulmonary complications challenge the medical management of patients who have sustained aneurysmal subarachnoid hemorrhage (SAH). We assessed the frequency and types of pulmonary complications after aneurysmal SAH and analyzed the impact of pulmonary complications on patient outcome.

We reviewed the records of all patients with acute SAH treated at our institution between 1990 and 1997. Three hundred five consecutive patients with an aneurysmal hemorrhage source documented by angiography and treated within 7 days of ictus were analyzed. Outcomes at longest follow-up (mean, 16 mo) were measured by use of the Glasgow Outcome Scale.

Pulmonary complications were documented in 66 patients (22%). The pulmonary complications were nosocomial pneumonia in 26 patients (9%), congestive heart failure in 23 (8%), aspiration pneumonia in 17 (6%), neurogenic pulmonary edema in 5 (2%), pulmonary embolus in 2 (<1%), and other pulmonary disorders in 4 (1%); 11 patients had two pulmonary complications. The incidence of symptomatic vasospasm was greater in patients with pulmonary complications (63%) than in patients without pulmonary complications (31%) (P = 0.001), and this association was independent of age and clinical grade at admission (odds ratio, 3.68; P < 0.001). Overall clinical outcomes were worse in patients with pulmonary complications (mean Glasgow Outcome Scale score, 3.3) than in patients without pulmonary complications (mean Glasgow Outcome Scale score, 4.0; P = 0.0001), but pulmonary complications were not an independent predictor of worse outcome when adjusted for age and clinical grade at admission (odds ratio, 1.38; P = 0.315).

Patients who experience pulmonary complications after aneurysmal SAH have a higher incidence of symptomatic vasospasm than do patients without pulmonary complications. This most likely reflects both the failure to maintain aggressive hypervolemic and hyperdynamic therapy in patients with pulmonary compromise and the possible precipitation of congestive heart failure by hypervolemic therapy in patients with preexisting delayed ischemic neurological deficit. Although patients with pulmonary complications have worse overall clinical outcomes than do patients without pulmonary complications, this is attributable to older age and worse clinical grades at admission.