Hypothesis: We hypothesize that PCT can be used to define normal (SIRS without infection) and abnormal values SIRS with infection (i.e., blood, lung, urinary, spinal fluid) in a population of patients with aneurysmal subarachnoid hemorrhage (SAH).
Specific Aim 1.) To establish normal values of PCT in patients with aneurysmal subarachnoid hemorrhage and SIRS.
Specific Aim 2.) Derive the sensitivity and positive predictive value of abnormal PCT values in patients with aneurysmal SAH, SIRS with true systemic infection.
Stroke is the third leading cause of death in the United States (AHA), A ruptured brain aneurysm leads to subarachnoid hemorrhage (SAH) which is a common but deadly stroke subtype (8% of all strokes). SAH one-month mortality is at least 30-40% from a combination of complications, being either cerebral (seizures, re-bleeding, hydrocephalus, herniation, coma, brain death) or extra-cerebral (pulmonary edema, myocardial stunning/infarction, hyponatremia, and SIRS). SIRS after subarachnoid hemorrhage is common, and is associated with the increased mortality of SAH (Yoshimoto Y). The pathogenesis remains of SIRS after SAH remains poorly understood, but theorized to be a results of catecholamines (e.g., adrenaline) and interleukins leading to increased heart and respiratory rate, increased peripheral white blood cell count and fever (Wartenberg K). Therefore SIRS after SAH mimics true systemic infection (e.g., sepsis) even when no true infection exists. Lack of treatment of true infection in SAH patients for presumptive non-infective SIRS can lead to missed sepsis and death.
- A prospective, observational study is proposed
- PCT levels will be obtained with daily intensive care unit laboratory values on the initial day (day #1), day 3, 5, 7, 9, 11, and 13.
- Patients with presumed infection will have the following comprehensive assessment per ICU standard of care when a SAH patient has a fever (i.e., temperature 38.5 oral or greater or 38.0 core temperature or greater): two sets of peripheral blood cultures, one cerebrospinal fluid (CSF) culture,
- All adult patients admitted for an expected ICU stay of more than 24 hrs over a 6-month period
- Patients with known hyper-bilirubinemia (>0.4 mg/ml) or hypertriglyceridemia (>10 g/l) will be excluded since this can interfere with measurements of PCT
Last updated: 06/06/2011