Abstract T P298: Impact of Accurate Weight Based Dosing of IV tPA in Acute Ischemic Stroke Patients

Abstract

Background: Accurate weight-based dosing is essential for efficacy and safety of thrombolysis in acute ischemic stroke (AIS). Stroke patients may be unable to communicate correct body weight (BW). Dosing may be estimated which can lead to error. Objective: To assess accuracy of weight estimation and the effect of weight and dosing discrepancy on outcome of patients with AIS Methods: 94 patients receiving IV tpa for AIS in a CSC registry between Feb, 2013 and Jul, 2014 were reviewed. All were given estimated weight based tPA- per patient input or agreement of 2 providers in ER. Accurate weights were obtained and recorded later. Actual weight was used to calculate the ideal TPA doses and compared to the weights and doses used. The cohort was separated into two groups based on weight discrepancy to those 10 kg (non forgiven) discrepancy. Rate of hemorrhage, NIHSS and hospice/mortality were assessed. Difference between categorical variables was tested using the chi-square and Fisher’ Exact Test. Differences between continuous variables were tested using Wilcoxon Rank Sum test and presented with median and IQ range. Results: 86.1% (forgiven cohort) were given the optimal tPA dose despite estimation. There was a significant difference in stroke severity based on admission NIHSS between the cohorts (33.3% in forgiven vs. 69.2% non-forgiven. P=0.04). Stroke severity based on discharge NIHSS did not reach statistical significance (mild: 71.8% vs 63.6%, moderate: 16.9% vs 9.1% and severe: 11.3% vs 27.3%, p = 0.32). 30 days modified Rankin Scale (mRS) was available for 52 pts without any significant difference (good outcome 44.4% vs 57.1%, poor outcome 35.6 % vs 28.6 %, p = 0.82). Statistically non significance toward higher rate of hemorrhagic conversion (6.4% vs 7.7%, p = 0.41), and higher mortality in non-forgiven group (7.41% vs 15.38%, p= 0.33). Conclusion: Accurate BW measurement prior tPA still remains challenging. In this study, weight estimation by 2 providers is fairly accurate. 14 % of the patients with discrepancy of > 10 kg had higher rate of mortality and hemorrhage although this was not statistically significant. Further studies with larger sample sizes are needed to examine the safety of weight estimation in AIS patients who receive IV tpa