Table 2.
Parameters studied, timeframe on sampling, outcome definitions, and factors adjusted
| First author (year) | Inflammatory parameters studied | Time from ictus to sampling | Exclusion criteria | Poor outcome | Factors adjusted in multivariate analysis | |
|---|---|---|---|---|---|---|
| Criteria used | Time point of evaluation | |||||
| Al-Mufti (2019) | WBC, RDW, NLR, NC, LC, PLT, % neutrophil, % lymphocyte | < 72 h (on admission) | NA | NA | NA | WFNS, APACHE-II, thick SAH on admission CT, smoking status, clipping repair |
| Wu (2019) | WBC, NC, LC, NLR | < 72 h (on admission) | Traumatic SAH, recent infectious diseases, prior neurological conditions including ischemic and hemorrhagic stroke, or brain trauma | NA | NA | Age, sex, Hunt and Hess, hydrocephalus, hypertension |
| Sokół (2018) | WBC, CRP | < 72 h (on admission) | Infection within 2 weeks before admission, nosocomial infection with the first week after admission, e.g., ventilator-associated pneumonia, chronic neurological disease, active chronic inflammatory disease, recurrent SAH, pregnancy | GOS 1 | 3 months | Age, Hunt and Hess |
| Frontera (2017) | CRP, %Neutrophil, Platelet activation | < 72 h (on admission) | Secondary SAH, ultra-early vasospasm or DCI, use of irreversible platelet inhibitors within 7 days or reversible platelet inhibitors within 4 half-lives of the first blood draw, intrinsic platelet dysfunction, thrombocytopenia, platelet transfusion, use of immunosuppressant drugs, known immunocompromised state | mRS 4–6 | 3 months | NA |
| Siegler (2017) | WBC, RDW, PLT | Early phase (days 1–14 mean) | Traumatic SAH, ischemic or hemorrhagic stroke, vascular malformation, coagulopathy or other secondary causes, as with perimesencephalic SAH | mRS 4–6 | At discharge | Age, sex, race, high Hunt and Hess, prior coronary artery disease, clipping, cerebral infarction, VTE |
| Tao (2017) | WBC, NC, LC, NLR, PLR | < 24 h (on admission) | Acute or chronic infection, history of autoimmune disease, previous stroke and recent cardiocerebrovacular disease, previous use of anticoagulant /anti-platelet medication, other prior systemic disease including malignancy, uremia, liver cirrhosis, chronic heart or lung disease | mRS 3–6 | 3 months | Intracerebral hemorrhage, hydrocephalus, admission glucose level |
| Chugh (2015) | CRP, WBC, RDW, PLT, fibrinogen, ESR, | < 24 h (on admission) | Antecedent head trauma, ischemic or hemorrhagic stroke, vascular malformation, or other secondary causes, perimesencephalic SAH | mRS 3–6 | 3 months | Age, Hunt&Hess, CBC and blood biomarkers |
| Csajbok (2015) | CRP | < 48 h (on admission) | NA | GOSE 1–4 | 1 year | Age, sex, infectious status during observation, WFNS, Fisher |
| Turner (2015) | CRP, WBC | < 96 h (on admission) | Taking statin, pregnancy, no reasonable prospect of survival, renal or hepatic impairment, not fully independent before bleed, strong suspicion of drug or alcohol misuse, unlikely to be amenable to follow-up, taking warfarin-type drugs or contraindicated medications, suspected additional life-threatening disease | mRS 3–6 | At discharge | Age, race, WFNS, Fisher, statin, infection and sepsis |
| Romero (2014) | CRP | < 24 h (on admission) | Concomitant or recent acute myocardial infarction, surgery within last 30 days, clinical or laboratory evidence of chronic systemic infection or acute infection | NA | NA | Hunt and Hess, Fisher grade, number of aneurysms, hemodynamic changes in Transcranial Doppler |
| McMahon (2013) | CRP, WBC, IL-6 | On admission | NA | NA | NA | Age, sex |
| Muroi (2013) | CRP, WBC, IL-6, Procalcitonin | Early phase (days 1–14) | Uncertain time of ictus, death within 3 days after admission, conservative or delayed aneurysm treatment | GOS 1–3 | 3 months | Infection, hypothermia, WFNS |
| Jeon (2012) | CRP | Postoperative days 1–2 | Prior clipping or coiling in other hospitals, overt or suspicious acute infection from admission until 7 days after surgery, chronic inflammatory diseases, chronic neurological diseases, or surgery of any kind within the last 4 weeks before admission | mRS 4–6 | At discharge | Ventilation, infarction, hydrocephalus, surgical decompression |
| Juvela (2012) | CRP | < 48 h (postoperative day 1) | Died before or soon after hospital admission, space-occupying ICH | GOS 1–3 | 3 months | Age, intraventricular bleeding, WFNS |
| Kasius (2009) | CRP, WBC, PLT, ESR | < 72 h (on admission) | Death on admission, DCI developed before admission | mRS 4–6 | 3 months | Infection, loss of consciousness at ictus, admission WFNS, amount of ventricular blood, signs of acute ischemia at ictus |
CRP C-reactive protein, WBC white blood cell count, NC neutrophil count, LC lymphocyte count, NLR neutrophil-to-lymphocyte ratio, PLR platelet-to-lymphocyte ratio, PLT platelet count, ESR erythrocyte sedimentation rate, RDW red blood cell distribution width, DCI delayed cerebral ischemia, mRS modified Rankin Scale, GOS Glasgow outcome scale, GOSE extended Glasgow outcome scale, WFNS World Federation of Neurosurgical Societies, NA not applicable