Pediatric emergency medicine trisk 2736 2736
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (71.68 KB, 1 trang )
(thorazine), and thiethylperazine (Torecan); and butyrophenones such as droperidol
and haloperidol. Since more effective antiemetics, such as serotonin-receptor
antagonists, have become available, the use of these drugs has decreased along with
the incidence of this side effect. If an extrapyramidal reaction is suspected,
management should include diphenhydramine 1 mg/kg IV (maximum dose 50 mg).
If symptoms are refractory to diphenhydramine, benztropine (Cogentin) should be
given at a dosage of 0.02 mg/kg IV (maximum 1 mg).
CARDIOVASCULAR COMPLICATIONS
Cancer treatment can affect cardiac function in patients during treatment and long
after completion of therapy. Anthracycline-induced cardiomyopathy is the most
common cause of cardiac damage in pediatric oncology patients although only a
small percentage are affected. Anthracycline chemotherapy, most commonly with
doxorubicin (Adriamycin) and daunorubicin (Daunomycin), is widely used in the
treatment of leukemia, lymphoma, sarcoma, and embryonal tumors such as
neuroblastoma and Wilms tumor. These drugs injure and potentially kill individual
cardiomyocytes and can cause acute cardiomyopathy during and up to 1 year after
the end of treatment. Late cardiomyopathy may develop 8 or more years after
completion of therapy. Typical findings on echocardiogram include decreased
shortening fraction/ejection fraction and/or increased afterload. Specific risk factors
include high total dose (greater than 300 mg/m2), high-dose rate, very young age at
treatment, and trisomy 21. Most regimens today are designed to minimize the risk of
cardiomyopathy by limiting total dose and dose rate and/or giving dexrazoxane, a
cardioprotectant.
Patients exposed to substantial doses of anthracycline are screened with
echocardiograms to look for early cardiac dysfunction. Early-onset cardiomyopathy
usually presents as acute cardiac failure or cardiac dysfunction out of proportion to a
stressor such as sepsis. Late-onset cardiomyopathy is generally a slowly progressive
process that may be detected on screening. Both forms may be associated with
arrhythmias. The initial management of this problem follows the standard regimen
for cardiac failure (see Chapter 86 Cardiac Emergencies ).
Radiation to the heart can cause long-term injury to the endothelial surfaces
leading to early-onset atherosclerotic vessel and/or valve disease. The heart is
exposed in mantle radiation for Hodgkin disease and total body irradiation as part of
a transplant preparative regimen.
Hypertension may occur in pediatric oncology patients due to steroid exposure,
salt overload, and renal injury from treatment. Most hypertension is not an
emergency and is better addressed by the treating oncologist as part of long-term
management. Hypertensive emergencies (see Chapter 37 Hypertension ) are rare in
pediatric oncology patients.
