Pain medication at ictus of subarachnoid hemorrhage-the influence of one-time acetylsalicylic acid usage on bleeding pattern, treatment course, and outcome: a matched pair analysis.

Acetylsalicylic acid (ASA) is a well-known and widely used analgesic for acute pain. Patients with acute headache due to subarachnoid hemorrhage (SAH) are inclined to take ASA in this situation. Due to the antithrombotic effects, ASA intake is related to higher bleeding rates in case of hemorrhage or surgical treatment. Between January 2006 and December 2016, 941 patients without continuous antithrombotic or anticoagulant medication were treated due to SAH in our institution. Fourteen of them (1.5%) had taken ASA as a single dose because of headache within 24 h before hospital admission. A matched pair analysis was performed. Admission status was good in 93% of patients with one-time use of ASA (OTA), but only in 59% of all other patients (p < 0.01). Bleeding pattern did not differ, but half of the patients with OTA had no identifiable bleeding source; this rate was significantly lower in the rest of the patients (p < 0.005). Aneurysm treatment and related complications did not differ between both groups. Cerebral vasospasm was more often only mild and rates of cerebral infarctions were lower in the OTA group but not on a significant level. Eighty-six percent of the OTA group and 84% (p = 0.8) of the matched pair control group reached favorable outcome according to mRS 6 months after SAH. Patients with OTA in case of SAH are usually in good clinical condition and bleeding pattern does not differ. In half of the patients with OTA, no bleeding source was detectable. In the case of aneurysm treatment, related complications did not differ and most of the patients reached favorable outcome. In the case of aneurysm treatment procedure, OTA does not influence treatment course and should not influence treatment decisions.