title: Tissue plasminogen activator for acute ischemic stroke: calculation of dose based on estimated patient weight can increase the risk of cerebral bleeding.
abstract: A dose of 0.9 mg/kg of intravenous tissue plasminogen activator (t-PA) has proven to be beneficial in the treatment of acute ischemic stroke (AIS). Dosing of t-PA based on estimated patient weight (PW) increases the likelihood of errors. Our objectives were to evaluate the accuracy of estimated PW and assess the effectiveness and safety of the actual applied dose (AAD) of t-PA. We performed a prospective single-center study of AIS patients treated with t-PA from May 2010 to December 2011. Dose was calculated according to estimated PW. Patients were weighed during the 24 h following treatment with t-PA. Estimation errors and AAD were calculated. Actual PW was measured in 97 of the 108 included patients. PW estimation errors were recorded in 22.7 % and were more frequent when weight was estimated by stroke unit staff (44 %). Only 11 % of patients misreported their own weight. Mean AAD was significantly higher in patients who had intracerebral hemorrhage (ICH) after t-PA than in patients who did not (0.96 vs. 0.92 mg/kg; p = 0.02). Multivariate analysis showed an increased risk of ICH for each 10 % increase in t-PA dose above the optimal dose of 0.90 mg/kg (OR 3.10; 95 % CI 1.14-8.39; p = 0.026). No effects of t-PA misdosing were observed on symptomatic ICH, functional outcome or mortality. Estimated PW is frequently inaccurate and leads to t-PA dosing errors. Increasing doses of t-PA above 0.90 mg/kg may increase the risk of ICH. Standardized weighing methods before t-PA is administered should be considered.
authors.affiliation: Stroke Unit, Neurology Department, Hospital General Universitario Gregorio Marañón, C/Dr. Esquerdo 46, 28007, Madrid, Spain, angarpas@yahoo.es.
authors.forename: Andrés
authors.initials: A
authors.lastname: García-Pastor
authors.forename: Fernando
authors.initials: F
authors.lastname: Díaz-Otero
authors.forename: Carmen
authors.initials: C
authors.lastname: Funes-Molina
authors.forename: Beatriz
authors.initials: B
authors.lastname: Benito-Conde
authors.forename: Sandra
authors.initials: S
authors.lastname: Grandes-Velasco
authors.forename: Pilar
authors.initials: P
authors.lastname: Sobrino-García
authors.forename: Pilar
authors.initials: P
authors.lastname: Vázquez-Alén
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Fernández-Bullido
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Villanueva-Osorio
authors.forename: Antonio
authors.initials: A
authors.lastname: Gil-Núñez
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D001835:Body Weight; D002545:Brain Ischemia / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006801:Humans; D020300:Intracranial Hemorrhages / Q000097:blood / Q000139:chemically induced / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000188:drug therapy*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D010959:Tissue Plasminogen Activator