RESUMO
UNLABELLED: Cardiotoxicity is a well recognized complication of anthracycline (AC) therapy. Subtle abnormalities in myocardial function that become apparent only after exercise may exist in survivors of childhood cancer who have previously received AC, yet have normal resting cardiac function. To evaluate if anesthesia-induced changes in cardiac function differ in pediatric patients with previous AC therapy from healthy children and adolescents, we evaluated in a prospective study 43 patients, of whom 42 were analyzed. Twenty-one patients (AC-group), mean age 9.6 yr (range, 3-16 yr), who had received 193 (30-490) mg/m(2) of AC as a mean cumulative dose with normal resting cardiac function (shortening fraction [SF] 0.34, normal value > 0.30) underwent removal of a Hickman catheter under general anesthesia. Twenty-one patients, mean age 10.9 yr (range, 4-17 yr), who underwent placement of a Hickman catheter before chemotherapy served as the control. All children were premedicated with midazolam 0.5 mg/kg orally. Anesthesia was induced by sodium thiopental (5 mg/kg), fentanyl (3 micro g/kg), and rocuronium (0.6 mg/kg) and maintained with isoflurane (1 MAC) in N(2)O/O(2) (70/30). Before induction (baseline), 5 and 20 min after intubation (T1 and T2), and 20 min after extubation (control), cardiac function was assessed by transthoracic (baseline, control) and transesophageal (T1, T2) echocardiography. Compared with baseline (SF: 34.9 +/- 3.7 [AC], 34.1 +/- 3.7 [C] [not significant]; stroke volume index [SVI] 36 +/- 6 mL/m(2)[AC], 35 +/- 4 mL/m(2)[C] [not significant]; cardiac index [CI] 3.6 +/- 0.6 L/min/m(2)[AC], 3.2 +/- 0.5 L/min/m(2)[C] [not significant]), we found a significant decrease in SF and SVI in both groups at T1 (SF: 26.2 +/- 3.6 [AC] versus 28.6 +/- 3.6 [C] [P < 0.05]; SVI: 26 +/- 4 mL/m(2) [AC] versus 30 +/- 46 mL/m(2) [C] [P < 0.05]) and T2 (SF: 24.1 +/- 3.2 [AC] versus 28.2 +/- 2.5 [C] [P < 0.01], SVI: 26 +/- 6 mL/m(2) [AC] versus 31 +/- 5 mL/m(2) [C] [P < 0.01]), which was significantly greater in the AC group. There were no significant changes of variables of diastolic function (E/A ratio, isovolumetric relaxation time) between both groups. Previous treatment with AC may enhance the myocardial depressive effect of anesthetics even in patients with normal resting cardiac function. IMPLICATIONS: Previous treatment with anthracylines, a group of chemotherapeutic drugs in use for childhood cancer, may enhance the myocardial depressive effect of anesthetics even in children and adolescents with normal resting cardiac function.
