Pediatric emergency medicine trisk 3071 3071
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (48.95 KB, 1 trang )
single digoxin overdoses. In fact, children with acute digoxin intoxication rarely
develop life-threatening illness if their peak SDC remains below 10 ng/mL.
The management of the patient with digoxin intoxication begins with
evaluation of hemodynamic status. Perform an EKG and provide continuous
cardiac monitoring. If significant cardiac arrhythmias are already present, treat
initially according to advanced cardiac life support protocols.
GI decontamination should include administration of activated charcoal.
Clinical assessment typically includes an EKG, electrolytes (including
magnesium and calcium) level, urinalysis, and SDC. Treat electrolyte
disturbances aggressively because they will aggravate any digoxin-induced
arrhythmias.
Digoxin-specific antibody fragments have become specific antidotal therapy
for reversing toxicity. This low–molecular-weight antibody fragment is capable of
avidly binding free digoxin, resulting in a gradient that favors digoxin removal
from receptor sites into interstitial water. This restores sodium–potassium ATPase
function. The digoxin–antibody complex is then rapidly excreted in the urine. Of
note, after digoxin-antibody fragments are administered, SDC increases
dramatically, reflecting bound, inactive digoxin that has diffused into the vascular
compartment.
These antibody fragments are indicated in the following circumstances after
digoxin poisoning: (i) Progressive signs and symptoms of intoxication, (ii) lifethreatening cardiac arrhythmias, or (iii) severe hyperkalemia (defined as a serum
potassium level of 5.5 mEq/L or higher). The dose of antibody fragments is
calculated on the basis of ingested digoxin dose (in the case of acute intoxication)
or on the basis of SDC (in the case of chronic intoxication). Each 40-mg vial of
digoxin-Fab will bind 0.6 mg of digoxin. The total dose of Fab needed (in vials)
may be estimated by dividing a known ingested dose by 0.6, or calculated for the
steady-state context as body load of digoxin:
Complications from the administration of antibody fragments include allergic
reaction (in approximately 0.6% of patients), precipitation of congestive heart
failure (secondary to the abrupt loss of digoxin’s inotropic action), and rebound
hypokalemia. These complications should be anticipated and treated accordingly.
Infuse over 30 minutes. If the patient is in cardiac arrest, the antibody fragments
may be infused over 5 minutes.
