CTA in acute stroke assessment

Transcription

1 CTA in acute stroke assessment Assumptions: It is more efficient to cancel an unnecessary CTA than to order a CTA after the fact It is more efficient to make 1 trip to the CT scanner Even if no LVO, CTA still gives useful information for stroke workup e.g. presence of carotid stenosis, intracranial stenosis, cervical dissection Optimized protocol: CTA is ordered automatically with code stroke activation CTA can be cancelled if: It is a stroke mimic based on ED physician or neurologists assessment Minor deficits that endovascular therapy would not be indicated ICH on initial CT Known contrast allergy **No waiting for labs unless known renal failure

2 Decision about creatinine testing and CTA Ask about Chronic Kidney Disease If no history of chronic kidney disease If patient is unable to give history and no family is available, or if already on hemodialysis If patient is known to have chronic kidney disease or renal transplant Check Creatinine and egfr Perform CTA without waiting for the creatinine Normal Creatinine and egfr Perform CTA High Creatinine egfr <35mL/min MD judgment on risk vs. benefit of CTA

3 Study design, patient population Number of scans CIN in no baseline Creatinine group CIN in Creatinine group or no CTA group Chronic renal failure, dialysis risk Comment Author, year patients, CTA, CTP, 150ml contrast 1075 Creatinine rise in 3.7% CIN in 0.37% Not applicable 2 patients 0.19% required temporary <6 days dialysis (both had pre-existing CRF), one of these had acute shock due to CABG and hypotension and shock liver. The other due to CIN. *Josephson SA, et al. Neurology patients, CTA Retrospective, Stroke/TIA, CTA, CTP, 140ml contrast or ICH patients, CTA, CTP Retrospective, Stroke, CTA/CTP, CIN in 2% within 3 days Raised Cr n 11% longterm CIN in 2% of all patients No CTA group: - CIN in 4% within 3 days - Raised Cr in 14% longterm 0, no dialysis Combination with catheter angiogram didn t increase CIN risk 0, no dialysis Calculated CIN risk score was low in the majority (83%) of patients. 25% of patients had abnormal Cr at baseline *Krol AL, et al Stroke Dittrich R, et al. J Neurol CIN in 2% Not applicable 0, no dialysis CIN in 2.9% of all patients *Hopyan JJ, et al. AJNR CIN in 2.6% Not applicable 0, no dialysis CRF history was not assessed! All patients were scanned unless history of anaphylactic reaction to iodinated contrast **Ang TE, et al. Int J Stroke Prospective dataset, retrospective study, stroke, CTA/CTP, 731 Baseline Cr. In everyone. Acute nephropathy in 3.7% overall - Occurred in 4.3% of patients without baseline renal dysfunction - 0ccured in 1.3% of patients with baseline renal dysfunction 0, no dialysis Renal dysfunction on admission was 21.2%, Baseline renal dysfunction had a paradoxical relationship with CIN suggesting other factors may be more important. Luitse MJ, et al (DUST). Int J Stroke * Creatinine if history of CRF ** only withheld CTA/CTP if there is a known anaphylactic reaction to iodinated contrast

4 Contrast Induced Nephropathy CIN Defined as: A 25% or more increase in baseline creatinine levels within 72 hours of contrast administration and maintained for =or>48hrs Or increase of the creatinine-level of > 0.5 mg/dl within 72 hours of contrast administration and maintained for =or>48hrs Typically levels peak around days 2 3 and then normalize within 2 weeks Risk factors: History of Chronic Kidney Disease, this is the dominant risk factor Hypotension/Hypovolemia/decreased cardiac output: This is an important risk factor in acute MI patients Diabetes mellitus: inconsistent evidence in stroke patients (but is a risk factor in MI patients undergoing PCI) Intra-aortic balloon pump, congestive heart failure and anemia: less common in stroke patients Volume of contrast: >2ml/kg, weak risk factor with heterogenous results in the literature Type of contrast: weak risk factor, non-ionic low osmolar agents being better

5 Stroke and CIN- Summary Stroke patients are at low risk of CIN ~2%, with none going on to long-term dialysis. Creatinine testing in acute stroke can be safely omitted if no history of chronic renal failure. Baseline renal dysfunction has an inconsistent relationship with CIN in stroke patients. LVO stroke patients have different CIN risk than MI patients undergoing PCI: Much less need for intra-aortic balloon pump Much lower incidence of hypotension, hypovolemia, cardiogenic shock and septic shock in stroke patients Nephropathy after stroke is more likely due to non-contrast issues than to contrast with CTA