Vasopressors and Inotropes

Abstract

Medication errors and adverse drug events occur more frequently in the intensive care unit compared to general care units.¹ Adverse drug events become more likely as patients receive more medications. Sentinel events and medication errors are more common as the number of failing organs increases.^2,3 Vasopressors are frequently associated with adverse drug events and they are considered high-alert drugs by the Institute of Safe Medication Practices due to their increased potential to cause harm.^4-6 Vasopressors and inotropes are used in patients with the highest acuity and under stressful situations which adds to the potential for errors. In addition, dosing guidelines, ranges and units are not always standardized across agents at specific institutions or for a certain agent across institutions. The literature is disparate with respect to dosing recommendations. With the exception of vasopressin, we report the dosing of these agents in a weight-based manner. This should enhance dosing consistency to help minimize errors. We encourage institutions to adopt this dosing scheme to reduce discrepancies associated with their administration. Moreover, using a weight based dosing strategy in an era of increasing obesity raises the question of whether actual, adjusted or ideal body weight should be used when administering vasopressors. No data are available to select an appropriate weight and trials evaluating the use of vasopressors rarely report the body weight used in cases of obesity. With the exception of milrinone, we encourage the use of ideal body weight for all weight-based dosing strategies because these agents possess short half-lives, rapid onsets, and low volumes of distribution but may be associated with severe adverse events when higher weights are used resulting in higher doses in heavier patients. Moreover, these agents are rapidly titrated to clinical response, so starting at lower doses based on ideal body weight is prudent.