Case report Immediate control of life-threatening digoxin intoxication in a child by use of digoxin-specific antibody fragments (Fab) P. HUSBY MD, P MD, PhD *, M. FARSTAD MD MD *, J.G. BROCK-UTNE MD, P MD, PhD †, M.E. KOLLER MD, P MD, PhD *, L. SEGADAL MD, P MD, PhD ‡, T. LUND MD, P MD, PhD * AND O.J. OHM MD, P MD, PhD ‡ *Department of Anesthesia and Intensive Care, University of Bergen, Haukeland University Hospital, 5021 Bergen, Norway, †Department of Anesthesia, Stanford University Medical Center, Stanford University School of Medicine, Stanford, CA, USA and ‡Department of Cardiology, University of Bergen, Haukeland University Hospital, 5021 Bergen, Norway Summary Digoxin-immune antibody fragments (Fab) for treatment of digitalis intoxication was introduced in 1976. Many reports have been published concerning this therapy for children, but few have focused on its immediate reversal of cardiac as well as extracardiac life- threatening manifestations of digoxin toxicity. We present a case of life-threatening digitalis intoxication in a child with postoperative renal insufficiency, after a Sennings procedure for transposition of the great arteries. Digoxin administration according to the nationally recommended dosage and intervals unexpectedly resulted in serum levels in the toxic range. Severe cardiac arrhythmias, haemodynamic instability and a rapid-increasing serum potassium level resulted. This report demonstrates how administration of Fab according to the manufacturer’s dosage recommendation reversed the tachyarrhyth- mia immediately and re-established a normal level of serum potas- sium within minutes. Keywords: digitalis poisoning; arrhythmias; hyperkalaemia; drug interaction; digoxin-immune antibody fragments Introduction Digoxin is, like other cardiac glycosides, a toxic drug with a narrow therapeutic window. It is therefore not surprising that toxicity is a common occurrence (1,2). One of the predisposing factors for digitalis poisoning is prerenal and renal failure together with the use of a series of drugs such as verapamil, phenytoin, spironolacton, thiazides and nonsteroidal anti-inflammatory drugs. These drugs all lead to increased bioavailability of cardiac glycosides, including digoxin (3). The difficulty in diagnosing digitalis intoxication arises from the nonspecificity of its associated signs and symptoms. Electrocardiographic findings of cardiac manifestations are also nonspecific. In addi- tion, the serum digoxin concentration does not always correlate with toxicity (4). Hyperkalaemia and refractory hypotension are often seen, but are Correspondence to: Paul Husby, Department of Anaesthesia and Intensive Care, University of Bergen, N-5021 Haukeland Hospital, Bergen, Norway (email: paul.husby@kir.uib.no). Paediatric Anaesthesia 2003 13: 541–546 Ó 2003 Blackwell Publishing Ltd 541