***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: BACKGROUND Triiodothyronine ( T(3 ) ) supplementation may be a useful adjunct in the management of patients after cardiopulmonary bypass . Limited data are available regarding the use and pharmacokinetics of T(3 ) in children . The present study was performed to evaluate T(3 ) pharmacokinetics in a cohort of children undergoing the modified Fontan procedure . METHODS AND RESULTS A total of 28 patients were enrolled in this r and omized , prospect i ve study . The patients were divided into 4 groups : 1 group received a placebo and 3 groups received intravenous T(3 ) at dosages of 0.4 , 0.6 , and 0.8 microg/kg , respectively . All 28 patients survived their operative procedures . Two patients developed low cardiac output , and 3 patients had pleural effusions . The median length of hospital stay was 7 days . The mean free T(3 ) level was 316+/-67 pg/dL after then administration of a placebo . Patients who received T(3 ) had mean peak free T(3 ) levels of 972+/-88 , 1351+/-299 , and 1869+/-281 pg/dL for the dosages of 0.4 , 0.6 , and 0.8 microg/kg , respectively . The calculated half-life of T(3 ) was 7 hours . CONCLUSIONS The half-life of intravenous T(3 ) in children is approximately one-third of that reported for adults . These results provide a framework for study ing the efficacy of T(3 ) supplementation in children undergoing open-heart surgery Epinephrine and calcium possess both cardiac inotropic and vasopressor activity . In addition , epinephrine 's cardiovascular effects are mediated via increases in intracellular calcium . As a result , many clinicians administer the two agents together in an attempt to augment their effects . Although this approach seems rational , it has never been proven effective . We evaluated the cardiovascular and hyperglycemic actions of epinephrine ( 10 and 30 ng/kg/min ) , with and without calcium chloride administration ( 10 mg/kg bolus followed by 2 mg/kg/hr infusion ) , in a prospect i ve , r and omized , blinded , crossover design ed study . Twelve adult patients were studied 1 day after aortocoronary bypass surgery . Calcium chloride raised ionized calcium levels from 1.06 + /- 0.03 ( mean + /- SEM ) to 1.44 + /- 0.05 mM ( p less than 0.05 ) . Calcium raised mean arterial pressure from 85 + /- 1 to 94 + /- 2 mm Hg ( p less than 0.05 ) but had no significant effect on cardiac index .  Epinephrine alone at 10 and 30 ng/kg/min significantly raised cardiac index from 2.7 + /- 0.2 to 3.0 + /- 0.2 ( p less than 0.05 ) and 3.6 + /- 0.3 ( p less than 0.05 ) l/min/m2 . After calcium , epinephrine failed to significantly increase cardiac index .  Epinephrine at 30 ng/kg/min significantly increased mean arterial pressure from 87 + /- 1 to 95 + /- 2 mm Hg ( p less than 0.05 ) . After calcium , epinephrine had no significant effect on blood pressure . In addition , epinephrine 's hyperglycemic effect was blunted by calcium . Plasma epinephrine levels were similar during control and calcium infusions . We conclude that calcium blunts epinephrine 's beta-adrenergic actions in postoperative cardiac surgery patients Thyroid hormone status was assessed in 132 children with congenital heart defects undergoing cardiac surgery ( median age 3.1 y ; range 2 d to 16.2 y ) .  Plasma TSH , thyroxine ( T4 ) , free thyroxine ( fT4 ) , triiodothyronine ( T3 ) , reverse triiodothyronine ( rT3 ) , thyroglobulin ( Tg ) , and urinary iodine excretion  were measured before and every other day after cardiac surgery ( d 1 - 21 ) . After surgery we observed strikingly low plasma concentrations of TSH ( 0.4 mU/L ; 0.2 - 1.3 ) , T3(0.6 nmol/L ; 0.3 - 1.2 ) , T4 ( 48.9 nmol/L ; 12.9 - 82.4 ) , fT4 ( 12.9 pmol/L ; 5.1 - 19.3 ) , and Tg ( 9.4 μg/L ; 1.5 - 20.6 ) , whereas rT3 plasma concentrations increased ( 0.13 pmol/L ; 0.05 - 0.3 ; n = 40 ) . The maximal postoperative changes of TSH and rT3 preceded changes of T3 , T4 , fT4 , and Tg . Postoperative urinary iodine excretion increased significantly ( n = 109 ) . Thyroid hormone plasma concentrations were lowest after cardiopulmonary bypass operations and in patients treated with dopamine . In patients with postoperative T3 plasma concentrations less than 0.6 nmol/L ( n = 52 ) the period of mechanical ventilation and intensive care treatment was significantly prolonged . Furthermore , the cumulative doses of inotropic and vasoactive catecholamines and furosemide were significantly higher in this patient group . Our results demonstrate transient secondary hypothyroidism  in children after cardiac surgery that may contribute to postoperative cardiac and respiratory dysfunction and may delay recovery . Possible benefits of thyroid hormone replacement therapy need to be thoroughly examined Purpose To compare the effectiveness of levosimendan and dobutamine in reducing pulmonary artery pressure ( PAP ) and increasing cardiac output for children undergoing cardiac surgery . Patients and methods The study included 50 patients with high systolic pulmonary artery pressure ( PAP ) undergoing surgical repair of cardiac septal defects . Patients were r and omly allocated to two equal groups : group L received levosimendan and group D received dobutamine .  PAP was measured preoperatively , by use of transthoracic echocardiography ( baseline ) , intraoperatively , directly , by use of a 22-gauge catheter inserted in the pulmonary artery , and postoperatively , by use of transesophageal echocardiography ( TEE ) . Cardiac index ( CI ) was recorded by use of a transesophageal 4-MHz Doppler probe . Results Both drugs significantly reduced PAP compared with the level at the time of induction of anesthesia . Mean PAP measurement before chest closure , 1 and 20 h after ICU admission were significantly lower for patients who received levosimendan ( 32.7 ± 4.1 , 25.8 ± 2.8 , 19.8 ± 2 mmHg , respectively ) than for those who received dobutamine ( 37.6 ± 2.75 , 32.8 ± 2.36 , 26.5 ± 2.2 mmHg , respectively ) . Both drugs significantly improved CI compared with its level at the time of induction of anesthesia . Mean CI measurements 5 min after weaning from cardiopulmonary bypass ( CPB ) until 20 h after ICU admission were significantly higher for patients who received levosimendan than for those who received dobutamine ( 3.55 ± 0.35 , 3.8 ± 0.36 , 3.81 ± 0.34 , respectively , in group L vs. 3.4 ± 0.36 , 3.6 ± 0.33 , 3.66 ± 0.29 , respectively , in group D ) . Conclusion Levosimendan is better than dobutamine for treatment of pulmonary hypertension of children undergoing cardiac surgery OBJECTIVES To compare the effectiveness and safety of amrinone and a combination of dopamine and nitroglycerin in infants after reconstructive surgery for congenital heart disease . DESIGN A prospect i ve , r and omized , double-blind study . SETTING Pediatric intensive care unit in a university hospital . PARTICIPANTS Thirty-two infants with complete atrioventricular septal defect . INTERVENTIONS Amrinone loading dose , 2 mg/kg , followed by a maintenance infusion , 7.5 micrograms/kg/min , was given to 17 infants before separation from cardiopulmonary bypass . The remaining 15 patients received a combination of dopamine , 5 micrograms/kg/min , and nitroglycerin , 1 microgram/kg/min . MEASUREMENTS AND MAIN RESULTS The circulatory state of the patients was evaluated from 4 to 18 hours after cardiopulmonary bypass . The systemic blood flow index , calculated using the Fick principle , was higher in the amrinone group ( 2.5 + /- 0.7 L/min/m2 ) compared with the dopamine-nitroglycerin group ( 2.0 + /- 0.6 L/min/m2 , mean + /- SD ) . The pulmonary blood flow index in the amrinone group was higher ( 2.9 + /- 0.6 L/min/m2 ) than in the dopamine-nitroglycerin group ( 2.2 + /- 0.6 L/min/m2 ) ; no significant difference was noted in the mean pulmonary artery pressure . The oxygen extraction ratio was higher in the dopamine-nitroglycerin group ( 0.41 + /- 0.07 ) compared with the amrinone group ( 0.34 + /- 0.08 ) . Despite lower platelet counts in the amrinone group , no hemorrhagic complications were seen in any patient . CONCLUSIONS With this dosage regimen , amrinone provides a higher cardiac output , more favorable oxygen dynamics , and lower pulmonary vascular resistance than dopamine and nitroglycerin BACKGROUND Milrinone , a phosphodiesterase inhibitor , enhances cardiac contractility by increasing intracellular levels of cyclic AMP , but the long-term effect of this type of positive inotropic agent on the survival of patients with chronic heart failure has not been determined . METHODS We r and omly assigned 1,088 patients with severe chronic heart failure ( New York Heart Association class III or IV ) and advanced left ventricular dysfunction to double-blind treatment with  ( 40 mg of oral milrinone daily ( 561 patients ) or placebo ( 527 patients ) . In addition , all patients received conventional therapy with digoxin , diuretics , and a converting-enzyme inhibitor throughout the trial . The median period of follow-up was 6.1 months ( range , 1 day to 20 months ) . RESULTS As compared with placebo , milrinone therapy was associated with a 28 percent increase in mortality from all causes ( 95 percent confidence interval , 1 to 61 percent ; P = 0.038 ) and a 34 percent increase in cardiovascular mortality ( 95 percent confidence interval , 6 to 69 percent ; P = 0.016 ) . The adverse effect of milrinone was greatest in patients with the most severe symptoms ( New York Heart Association class IV ) , who had a 53 percent increase in mortality ( 95 percent confidence interval , 13 to 107 percent ; P = 0.006 ) . Milrinone did not have a beneficial effect on the survival of any subgroup . Patients treated with milrinone had more hospitalizations ( 44 vs. 39 percent , P = 0.041 ) , were withdrawn from double-blind therapy more frequently ( 12.7 vs. 8.7 percent , P = 0.041 ) , and had serious adverse cardiovascular reactions , including hypotension ( P = 0.006 ) and syncope ( P = 0.002 ) , more often than the patients given placebo . CONCLUSIONS Our findings indicate that despite its beneficial hemodynamic actions , long-term therapy with oral milrinone increases the morbidity and mortality of patients with severe chronic heart failure . The mechanism by which the drug exerts its deleterious effects is unknown Nineteen children , aged 2 - 54 months , requiring high-dose inotropic support after cardiac surgery , were given either dopamine or dobutamine in a blinded , double crossover , study . Using a pulmonary artery thermistor , right and left atrial cannulae , and pulmonary and femoral arterial catheters , conventional haemodynamic variables were measured hourly over three consecutive 4 h dopamine-dobutamine-dopamine or dobutamine-dopamine-dobutamine exchanges . No significant differences in haemodynamics occurred during dopamine therapy compared with the same dose of dobutamine in 14 patients receiving phenoxybenzamine 2 mg kg-1 , four of whom had also received enoximone . In five patients , neither enoximone nor phenoxybenzamine was used and significant increases in pulmonary artery pressure and pulmonary vascular resistance ( P = 0.04 ) occurred when patients were given dopamine rather than dobutamine . We conclude that dobutamine and dopamine are equipotent inotropes in children and that dopamine in doses > 7 micrograms kg-1 min-1 , caused pulmonary vasoconstriction , an effect mediated by alpha adrenergic receptors Objectives : Persistent pulmonary hypertension of the newborn is a common problem with significant morbidity and mortality .  In 
    Output:
    
A systematic review of the literature failed to show compelling evidence with regard to the benefit of inotropes .
Conclusions : Despite the lack of sufficient evidence , milrinone is used by the vast majority of caregivers following congenital heart surgery