Potassium Chloride

This document serves as a revision to the Society of Family Planning's 2010 guidelines, integrating literature on new techniques and research and addressing the clinical, medical, and sociolegal questions surrounding the induction of fetal asystole. Insufficient evidence exists to recommend routine induction of fetal asystole before previable medication and procedural abortion. However, at periviable gestations and after fetal viability, inducing fetal asystole before abortion prevents the infrequent but serious occurrence of unanticipated expulsion of a fetus with cardiorespiratory activity (Best Practice). Defining viability is complicated as it represents a physiological continuum impacted by gestational duration along with multiple other individual clinical factors and circumstances; therefore, the exact gestational duration to offer fetal asystole will depend on the setting and clinical circumstances. If induction of fetal asystole before abortion is available, we recommend engaging in patient-centered counseling regarding the risks and benefits of induction of fetal asystole in the setting of each unique pregnancy scenario and the patient's beliefs and priorities (Best Practice). We recommend that clinicians identify the optimal pharmacologic agent to administer for a given clinical scenario based on factors such as availability of each agent; the time frame in which fetal asystole needs to be established; and clinicians' technical ability, preferences, and practice (Best Practice). Potassium chloride, lidocaine, and digoxin are all acceptable pharmaceutical agents to induce fetal asystole before abortion. To establish asystole rapidly, we suggest the use of potassium chloride (via intracardiac or intrafunic injection) or lidocaine (via intracardiac or intrafunic injection) (GRADE 2C), although intrathoracic administration of lidocaine may be acceptable. We recommend potassium chloride not be used if intracardiac or intrafunic location cannot be achieved to avoid the risk of accidental administration to the pregnant individual and because insufficient data support its efficacy via other intrafetal locations (GRADE 1C). When using digoxin, we recommend intrafetal administration (GRADE 1C), although intraamniotic administration may be acceptable depending on a clinician's technical ability and setting. Because digoxin may take several hours to induce asystole, an alternative agent should be considered in settings where fetal asystole must be confirmed rapidly.