Poor-grade aneurysmal subarachnoid hemorrhage complications
These patients more often present with acute hydrocephalus, severe intraventricular hemorrhage, microcirculatory disturbances, and even multi-organ failure after ictus 1) 2).
Mortality
A systematic literature review showed a mortality rate of 60% in patients with WFNS IV and V and, of these, about 29% died before any aneurysm treatment 3).
1)
Hutchinson PJ, Power DM, Tripathi P, Kirkpatrick PJ. Outcome from poor grade aneurysmal subarachnoid haemorrhage–which poor grade subarachnoid haemorrhage patients benefit from aneurysm clipping? Br J Neurosurg. 2000 Apr;14(2):105-9. doi: 10.1080/02688690050004516. PMID: 10889881.
2)
Wartenberg KE, Sheth SJ, Michael Schmidt J, Frontera JA, Rincon F, Ostapkovich N, Fernandez L, Badjatia N, Sander Connolly E, Khandji A, Mayer SA. Acute ischemic injury on diffusion-weighted magnetic resonance imaging after poor grade subarachnoid hemorrhage. Neurocrit Care. 2011 Jun;14(3):407-15. doi: 10.1007/s12028-010-9488-1. PMID: 21174171.
3)
de Oliveira Manoel AL, Mansur A, Silva GS, Germans MR, Jaja BN, Kouzmina E, Marotta TR, Abrahamson S, Schweizer TA, Spears J, Macdonald RL. Functional Outcome After Poor-Grade Subarachnoid Hemorrhage: A Single-Center Study and Systematic Literature Review. Neurocrit Care. 2016 Dec;25(3):338-350. doi: 10.1007/s12028-016-0305-3. PMID: 27651379.