Investigation of suspected aneurysmal subarachnoid haemorrhage: a single-centre quality improvement project

Introduction Aneurysmal subarachnoid haemorrhage (aSAH) has a global incidence of 6/100,000 person-years, affects people of working age and is associated with a high case fatality rate. 1,2 Between 10% and 43% of cases present with a sentinel headache, which necessitates investigation including a non-contrast computed tomography (CT) head and lumbar puncture (LP). 3 The Ottawa SAH rule is sensitive but only 15% specific, resulting in many people being investigated. 4 This project assessed the investigation of suspected aSAH at the Royal Liverpool University Hospital to guide service improvements, with reference to National Institute of Health and Care Excellence (NICE) guidelines. 5 Materials and Methods Cases were identified by searching the Telepath laboratory management system for all cerebrospinal fluid (CSF) samples that underwent xanthochromia analysis in 2024. Acute medicine clinicians screened the electronic patient records, only included cases where suspected aSAH was the primary reason for undertaking the LP, and extracted clinical, laboratory and radiological data. Statistical analyses were conducted using R v 4.4.2. Results and Discussion There were 187 CSF samples evaluated for xanthochromia, of which 107 (57.2%) were cases where aSAH was the primary reason for investigation and were included in this analysis. Ottawa SAH Rules were fulfilled as follows: thunderclap headache, 63.6%; age ≥40, 59.8%; neck pain or stiffness, 33.6%; onset during exertion, 17.8%; limited neck flexion, 13.1%; and loss of consciousness, 12.1%. There were 6 (5.6%) cases that underwent LP where all Ottawa criteria were either negative or not documented. The median time interval from admission to LP was 23.0 h (IQR 12.7–36.9 h; Fig 1). There were 15 (14%) cases who were triaged within 5 h of headache onset, for whom NICE guidelines advise that aSAH can be excluded based on a non-contrast computed tomography (CT) head performed within 6 h of headache onset, without the need for LP. Nine (60%) of these cases had a non-contrast CT within 6 h of headache onset, yet all proceeded to LP, which were all negative for xanthochromia. Patients admitted or streamed to the same-day emergency care (SDEC) unit had a significantly lower time to LP, compared with cases admitted to the emergency department and transferred to a ward (median 20.2 h vs 44.5 h; Mann-Whitney U, p<0.001). Clotting studies were undertaken for 101 (94.4%) cases, which were unnecessary in 90 (89.1%) cases. The xanthochromia result was positive in 3 (2.8%) cases, negative in 99 (92.5%), inconclusive in 3 (2.8%), and invalid in 2 (1.9%). Among the three cases with a positive xanthochromia, one had an aneurysm identified, which was coiled. Serious LP-related complications were post-LP headaches, which resulted in a prolonged hospital stay (n=2) or re-admission (n=3). Conclusion Multiple adaptations to provide timely diagnosis, and reduce cost and reduce length of hospital stay were identified, including: better adherence to Ottawa SAH rules; when possible, undertaking an urgent CT head within 6 h of headache onset; appropriate use of clotting studies; and streaming appropriate cases to SDEC. Our aSAH pathway is being updated to reflect these recommendations and NICE guidelines. 5

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.