> [!References]- > - on BP mgmt controversy; first two links are 2023 updates on SAH mgmt .from AHA/stroke and neurointensive care, respectively: [2023 Guideline for the Management of Patients With...](cubox://card?id=7124828344629070399) > - [Blood Pressure Targets for the Prevention of Reble...](cubox://highlight?id=7124833961750040230) > - [Blood Pressure Management After Intracerebral and ...](cubox://card?id=7124820175462860849) > > Fellowship resources: > - [Rosen SAH](x-devonthink-item://1781B09F-B327-4348-AA6F-F427FF97CA97?page=5) > - [Dunn SAH](x-devonthink-item://FC2A2A08-65F0-4CE6-A466-C44756664E22), [ Dunn investigation of suspected SAH](x-devonthink-item://7E6AD08C-BDB2-4128-86B6-90E833EE7E96), [Dunn management of SAH](x-devonthink-item://1F87C478-B735-4707-95B0-4E9D2C021903) > - [Core radiology - Subarachnoid Hemorrhage](x-devonthink-item://C1EF00FD-576C-4C41-AE08-CA966611F572?page=690) > - [Radiology Case studies - Subarachnoid Hemorrhage](x-devonthink-item://2A71AF1A-4715-4D5F-9841-03401D8E6C4E?page=461) > > NZ study on CTB timing: [[Multisclice CT for SAH]] > - single centre > - MSCT identified 253 (97.3%) of all aneurysmal SAH and 332 (95.7%) of all SAH. > - Sensitivity of MSCT was 99.6% (95% CI 97.6 to 100) for aneurysmal SAH and 99.0% (95% CI 97.1 to 99.8) for all SAH at 48 hours after headache onset. > - At 24 hours after headache onset, the sensitivity for aneurysmal SAH was 100% (95% CI 98.3 to 100). > - ==single-centre retrospective study suggests that it may be possible to extend the timeframe from headache onset in which modern MSCT can be used to rule out aneurysmal SAH== > > UK study on CTB timing: [[SHED]] > - prospective, observational, multicentre cohort study > > Nimodipine meta analysis: [Calcium antagonists for aneurysmal subarachnoid haemorrhage - cochrane 2007](https://www.cochranelibrary.com/web/cochrane/content?templateType=full&urlTitle=/cdsr/doi/10.1002/14651858.CD000277.pub3&doi=10.1002/14651858.CD000277.pub3&type=cdsr&contentLanguage=) > - “Calcium antagonists reduce the risk of poor outcome and secondary ischaemia after aneurysmal SAH. The results for 'poor outcome' depend largely on a single large trial of oral nimodipine; the evidence for other calcium antagonists is inconclusive. The evidence for nimodipine is not beyond all doubt, but given the potential benefits and modest risks of this treatment, oral nimodipine is currently indicated in patients with aneurysmal SAH. Intravenous administration of calcium antagonists cannot be recommended for routine practice on the basis of the present evidence. Magnesium sulphate is a promising agent but more evidence is needed before definite conclusions can be drawn.” > [!Key Points] > - nimodipine 60mg Q4h oral or ngt > - See also: [[Head trauma radiology#Traumatic Subarachnoid haemorrhage]] # causes - 70% ruptured berry aneurysm - 85% anterior circle of willis - 30% junction of anterior cerebral artery and ACOM - 25% junction of ICA and PCA ~ 3.5-7% of general population of asymptomatic aneurysms - F>M Isolated perimesencephalic SAH - 15% of cases - good prognosis - neurologic complications rare - recurrence rare ## risk factors - prior SAH - female > M - smoking - HTN - FMx - connective tissue disease: - autosomal dominant polycystic disease - marfans - NF1 - a-1-antitrypsin def - fibromuscular dysplasia - hereditary haemorrhagic telangiectasia - tuberous sclerosis - others - finish or japanese ethnicity - ethanol binges # history - headache - reaches peak intensity within 10 min - 1 hour - may improve spontaneously or with treatment; however, complete resolution within hours is rare - ==20% of pts with SAH also have a history of migraine== - occipital or neck pain suggests aneurysm of PICA or AICA - eye or temple pain suggests MCA aneurysm - other sx - vomiting common - transient LOC → due to cerebral perfusion pressure fall at onset as ICP approaches MAP. highly specific for SAH. a/w worse prognosis ## DDx for "thunderclap headache" - idiopathic - [[carotid and vertebral artery dissection|carotid or vertebral artery dissection]] - [[intracerebral haemorrhage|ICH]] - cerebral venous sinus thrombosis - although usually more gradual in onset - benign post coital sudden onset headache - benign post exertional sudden onset HA - pituitary apoplexy - RCVS # complications **immediate complications** - myocardial dysfunction - [[STEMI mimics]] / [[#ecg changes|cerebral t waves]] - APO **delayed complications** - re-bleeding - vasospasm and delayed neuro deficit - 30% - usually btn days 4-14 - occurs in response to breakdown of blood products in subarachnoid space - ==may be prevented by nimodipine== - hydrocephalus - may require ventricular drainage - [[hyponatremia]] (cerebral salt wasting) - [[Seizures]] # Decision tools ## Hunt and Hess clinical grading for SAH | Grade | condition | outcomes <br>(independent / death) | | ----- | ----------------------------------------------------------------------------------- | ---------------------------------- | | 0 | unruptured aneurysm | | | 1 | asymptomatic or minimal HA and slight nuchal rigidity | 90-95% /<br>1-2% | | 2 | mod or severe HA, nuchal rigidity, no neuro deficity other than cranial nerve palsy | | | 3 | drowsiness, confusion, or mild focal deficit | | | 4 | stupor, moderate to severe hemiparesis | 10% /<br>80% | | 5 | deep coma, decerebrate posturing, moribund appearance | | ## Ottawa SAH clinical decision rule - age ≥ 40 - neck pain or stiffness - loss of consciousness - onset during exertion - thunderclap (instantly peaking) HA - limited neck flexion on exam if 0 of these, SAH ruled out # ecg changes See also: [[T inversion DDx]] - [Cerebral t waves LITFL](https://litfl.com/raised-intracranial-pressure-ecg-library/) - [[Long QT]] - Bradycardia SAH ECG - Widespread, giant T-wave inversions (“cerebral T waves”) secondary to subarachnoid haemorrhage. The QT interval is also grossly prolonged: ![[75E40827-3E23-4520-BE51-86EEEB982EF1.jpeg]] Severe [[traumatic brain injury|TBI]] with ↑ ICP: ![[B390B53F-CEA5-4C8C-AA6E-59B9EC24099D.jpeg]] # CTB distributions of blood location of blood suggests the cause - aneurysmal/AVM/dissection -- diffuse: blood in basal cisterns, sylvian fissure, interhemispheric fissure - isolated convexity SAH near cortex : - young RCVS - older cerebral amyloid angipathy or traumatic - permesencephalic pre-pontine - venous bleeding origin, better prognosis # sensitivity of CT <6 hours? ~ 95-98% in first 24 hours can demonstrate presence of SAH blood in >95% of cases. <6 hours closer to 98%. do LP if high clinical index of concern in spite of negative CTB. per Dunn, multi-detector CTB (most common in Aus/Nz) negative within 48-72 hours mostly rules out SAH; claim LP following negative plain CT in ED has a true positive yield of 0.4% overall, and 1:2000 if new generation CT within 6 hours.   *factors that may decrease sensitivity of non-con CTB?* - HCT <30 - small vol bleed - posterior fossa bleed - increased time from sx onset - radiology reporting from non-neurospecialist radiologist # Treatment - ==nimodipine 60mg Q4H oral or NGT== - analgesia - maintain cerebral perfusion pressure while avoiding excess rise in MAP - BP 110-160 systolic - [[labetalol]] (esmolol would also work) - [[Nicardipine]] - [[hydralazine]] - reduce raised ICP - head up 30 deg - [[traumatic brain injury#Hypertonic saline|hypertonic saline]] 3mL/kg over 10 min (or 100mL 3%) or manitol 0.5-1mg/kg IV if ↑ ICP - keppra loading dose 60mg/kg - may need EVD if interventricular blood or high grade SAH (risk of obstructive hydrocephalus > do NOT use GTN or sodium nitropruside; these vasodilate and can cause increased intracranial pressure # Related Questions ## collapse - [x] 2Q: [Collapse, cause unclear](x-devonthink-item://8AAAF35C-CCF4-4157-9551-5B05727AA0CD?page=13) -- [Answer](x-devonthink-item://FDFBA3A1-6207-4204-AB6D-7483D80C5B5C?page=13) ## confusion - [x] 3Q: [Confused patient with VP shunt](x-devonthink-item://4BE7EDE1-1843-4BA0-B8D2-0DCEF50784D4?page=1) -- [Answer](x-devonthink-item://15F8F701-8EC8-4F9A-8DEC-5220C8561C8A?page=1) - [x] 4Q: [Cirrhosis and Confusion](x-devonthink-item://C4CCEB12-61D5-4308-AA41-5078F3D96CC0?page=10) -- [Answer](x-devonthink-item://75D8E35B-EE77-4D1B-A665-438451C976AE?page=16) - [ ] 5Q: [Confused Adult](x-devonthink-item://7061D1B4-0AB9-4963-B3B0-23BDD975B2CD?page=24) -- [Answer](x-devonthink-item://3F30C77E-E23E-4200-89FE-48A41618E0C2?page=16) ## headache - [ ] 11Q: [Possible meningitis](x-devonthink-item://554C45F7-8661-4467-BD61-8A79B6ECABF4?page=34) -- [Answer](x-devonthink-item://554C45F7-8661-4467-BD61-8A79B6ECABF4?page=36) - [ ] 12Q: [Headache](x-devonthink-item://F0498813-9350-484C-AD5B-6FF7C3AE9015?page=46) -- [Answer](x-devonthink-item://A491A3F6-FD6D-492F-BCBE-7F7BAE101EDF?page=50) - [ ] 13Q: [VP Shunt Complication](x-devonthink-item://7FCD3940-4BB4-45FE-86A6-E5707E82D5B5?page=28) -- [Answer](x-devonthink-item://3263A68A-96A6-43EC-985B-43260C3509BF?page=9) ## sah - [ ] 15Q: [Subarachnoid haemorrhage](x-devonthink-item://FE3157C2-07B3-43F2-9ECE-AFACE1355E13?page=2) -- [Answer](x-devonthink-item://DDC959EB-0C1E-448A-8380-C397BF734322?page=0) - [ ] 16Q: [Headache and Collapse with Abnormal CT](x-devonthink-item://3D57C3FE-3B52-42E0-9FBD-E4034F60C5B7?page=11) -- [Answer](x-devonthink-item://75D8E35B-EE77-4D1B-A665-438451C976AE?page=25) ## subarachnoid haemorrhage - [x] 17Q: [Severe headache and confusion](x-devonthink-item://554C45F7-8661-4467-BD61-8A79B6ECABF4?page=43) -- [Answer](x-devonthink-item://554C45F7-8661-4467-BD61-8A79B6ECABF4?page=45) - [x] 18Q: [Subarachnoid haemorrhage](x-devonthink-item://4134DDB3-6E12-474A-9F6F-64135C0C6048?page=25) -- [Answer](x-devonthink-item://AC92B5F1-8EE6-461A-B03E-F70AE7DC1275?page=25) - [x] 19Q: [Subarachnoid haemorrhage](x-devonthink-item://310EEEDE-D794-4365-8865-5B3DD1C20510?page=4) -- [Answer](x-devonthink-item://6D5125AD-DE4D-435B-8D13-6EA35DB8E785?page=4) - [x] DUPLICATE Q: [Subarachnoid haemorrhage](x-devonthink-item://FE3157C2-07B3-43F2-9ECE-AFACE1355E13?page=2) -- [Answer](x-devonthink-item://DDC959EB-0C1E-448A-8380-C397BF734322?page=0) - [x] DUPLICATE Q: [Headache and Collapse with Abnormal CT](x-devonthink-item://3D57C3FE-3B52-42E0-9FBD-E4034F60C5B7?page=11) -- [Answer](x-devonthink-item://75D8E35B-EE77-4D1B-A665-438451C976AE?page=25) - [ ] 20Q: [Collapse and Reduced GCS](x-devonthink-item://09CFA1A7-00F1-4151-979E-8F3984924D54?page=19) -- [Answer](x-devonthink-item://CF5E9C2B-42F9-4F9C-AC29-877E20134927?page=12) ## ottawa SAH - [ ] [question](x-devonthink-item://09493372-578D-4C97-972A-EEC617B38B53?page=4) -- [Answer](x-devonthink-item://A0D348CE-FCD4-4ECD-BE21-6CA73F6DE8CD?page=1)