Dosing of Vasopressin in Critically Ill Children: Implications for Medication Safety.

To the Editor: We read with great interest two recent studies published in Pediatric Critical Care Medicine regarding the use of vasopressin to augment cardiac output in neonates and children following cardiac surgery (1, 2). In our review of these studies, we noted that there is an inconsistency in vasopressin dosing units reported by the authors. Alten et al (1) describes their experience with vasopressin dosing in U/kg/min. In contrast, Davalos et al (2) describe their dosing in mU/kg/min. This inconsistency in vasopressin dosing was also noted in three medication references, which are provided in Table 1 (3–5). This highlights a need to address the inconsistency in dosing units, with specific regard to patient safety. It is our opinion that this discrepancy in dosing has the potential to compromise patient care. First, there is a potential for miscommunication of dosing between providers depending upon the medication reference used and the provider’s background and training. Second, these different dosing discrepancies can cause significant programming issues when using smart pump technology. There could be significant medication errors in institutions that allow programming for various dosing units versus programming a standard dosing unit in the medication infusion pump. This may be further complicated because many medication references provide different dosing and dosing units based on different indications (e.g., diabetes insipidus and gastrointestinal bleeding) (Table 1). Third, these dosing discrepancies could result in calculation errors, specifically during emergencies or emergent calculations at the bedside. Fourth, there could also be additional discrepancies with interhospital transport. Based on the discrepancy in medication references, it is likely that many facilities have adopted different preferred dosing units, thus leading to further confusion. Our recommendation would be for each facility to adopt one standard dosing unit for shock, diabetes insipidus, and gastrointestinal bleeding. It is our opinion that adopting one standard dosing unit would lead to less confusion among providers, pharmacists, and nursing staff and reduce dosing errors. To illustrate this point, Table 1 provides a summary of dosing for all three indications based on the various dosing units. Some institutions have universally adopted mU/kg/min for all indications. The primary reason for this is that if U/kg/min was used, the dosing need for a child with diabetes insipidus may not be programmable in a smart pump due to the requirement of doses with greater than four significant digits after the decimal point (e.g., 0.000008 U/kg/min). Although it should be noted, most of the recent publications with vasopressin infusions in children with septic or cardiogenic shock describe dosing in U/kg/min. So, institutions that implement one standard dosing unit should provide education to providers, pharmacists, and nursing staff to ensure successful implementation. Drs. Johnson and Miller have received support from the American Society of Health-System Pharmacists for the development of educational presentations for the Pediatric Pharmacy Board Certification program. Dr. Miller is on the speaker’s bureau for Chiesi, USA, Inc. Dr. Johnson has received seed grant funding from the University of Oklahoma Colleges of Pharmacy and Medicine. Dr. Ranallo has disclosed that she does not have any potential conflicts of interest.