Emergency clinicians’ interpretation and application of Anti-D guidelines

Objective: The objective of this study was to audit the use of anti-D immunoglobulin (anti-D) against the current Australian guidelines in one large inner-city referral hospital over three years and critique the practice identified. Background: Pregnant patients who have a D-negative (RhD negative) blood type are at risk of D alloimmunisation if a potentially sensitising event occurs during pregnancy or birth. The administration of anti-D Ig can prevent complications related to alloimmunisation. Potentially sensitising events commonly present to the emergency department requiring the administration of anti-D Ig in line with current guidelines. Study Design and Methods: This is a retrospective cohort study of all patients who received anti-D Ig in a large inner-city emergency department (ED) over three years (July 2014 – June 2017). Indications for administration were scrutinised against current guidelines by experienced clinicians. Results: A total of 228 patients received anti-D Ig, with the majority being less than twelve weeks in gestation (169, 74.1%). Anti-D Ig was administered without support from the guidelines in 81 (35.5%) patients, with a lack of documented sensitising event in 77 (95%) of these cases. Discussion and Conclusion: There were inconsistencies amongst clinicians who prescribe anti-D Ig in the ED, and a lack of the application of current guidelines. This may stem from a lack of empirical evidence about the need for anti-D Ig in the most common group presenting to EDs, those under twelve weeks in gestation. Current guidelines also fail to take into consideration future need, which could be incorporated in future, ED specific anti-D Ig guidelines. Implications for research, policy, and practice: This audit identified overuse of anti-D Ig in the ED. This may stem from the absence of evidence for its use in pregnant patients under 12 weeks in gestation. To reduce unsupported use, further data on alloimmunisation rates following potentially sensitising events in early pregnancy would be helpful. Additional guidelines specific to patients under 12 weeks in gestation, and presenting to the emergency department may reduce some unsupported usage. What is already known about the topic? • Pregnant patients who have an D-negative blood type are at risk of D alloimmunisation when a sensitising event occurs. • It is common for patients to present to the emergency department with complications in early pregnancy • Previous work has shown that there is variation in anti-D Ig administration in the emergency department. What this paper adds: • There is significant use of anti-D Ig in the emergency department that is outside of current guidelines. • The current guidelines may not serve the needs of the majority of presentations in the emergency department. • Further data on alloimmunisation rates following potentially sensitising events in patients less then twelve weeks of gestation would be useful.