Inhaled iloprost and nitric oxide for pediatric pulmonary hypertension after congenital heart operation

Abstract

Objective To investigate the hemodynamic effects and mechanisms of aerosolized iloprost in children with pulmonary hypertension(PAH)after congenital heart surgery,in the setting of early ventilation and continuous nitric oxide(NO)inhalation were administered.To observe the outcomes of the patients after iloprnst therapy.Methods From April 2008 to April 2009,all postoperative children with PAH in ICU,Fuwai hospital had regularly been given ventilation and NO inhalation at a dose of 10 ppm for 2 hours since they were leaving the operation room,and then ultrasonic cardiography was used to evaluate the systolic pulmonary arterial pressure(sPAP=4×TIVmax+RAP).Thirty children were diagnosed as having postoperative PAH for sPAP/sBP≥0.5.They were divided into two groups(group T and group C)randomly,with ventilation and NO inhalation administered continuously,and were given inhaled iloprost at a dose of 100 ng·kg-1·min-1*10 min and inhaled 0.9% NaCl 4ml respectively,once every 4 hours for 48 hours.We used the 24-hour cardiac monitors and ultrasonic cardiography for hemodynamic monitoring in the patients of two groups at the six time points:baseline(t1),20 min later after the first inhalation(t2),120 min later after the first inhalation(t3),24 hours later after the treatment(t4),48 hours later after the treatment(t5) and 24 hours after ceasing the last inhalation(t6).We examine the blood cAMP and cGMP by ELISA assay before and after the first inhalation.We observed the blood coagulation,the liver and kidney function of these patients.The outcomes of these patients were also investigated.Results At t1,the sPAP and sPAP/sBP had no differences between the two groups.At t2,the sPAP(43.23±11.72)mmHg and sPAP/sBP(0.48±0.13)in group T were both lower than the sPAP(53.13±13.60)mmHg and sPAP/sBP(0.60±O.15)in group C(P<0.05).At t3,the sPAP/sBP of group T was also lower than that of group C(0.48±0.09 vs 0.59±0.14,P<0.05).At t4 and t5,the sPAP in group T were (39.84±12.87)and(34.99±12.98)mm Hg,with sPAP/sBP(0.42±0.15)and(0.36±0.14),were much lower than those in group C(P<0.01).From t1 to t2,the cAMP level increased sharply from(406.64±179.18)to(578.68±193.05)pg/dl in group T(P<0.01),and was also obviously higher than that in group C at t2(392.26±94.46)pg/dl(P<0.01).HR,BP and RAP showed no notable difference between two groups at every time point.So did the PIP.There were no differences in coagulation,liver and kidney function at t6.2 patients died from pulmonary hypertension crisis(PAH)in group C and no one in group T.One patient showed flush during the treatment in group T and recovered spontaneously after the inhalation.Nevertheless,none in group C.Conclusiou Inhaled iloprost significantly improved pulmonary hemodynamics in children with PAH after congenital heart operation even thongh they were ventilated and inhaling NO.Increased blood cAMP level was considered to be a contributing factor.Howeve,systemic BP remain unaffected after iloprost inhalation.Aerosolized iloprost may be associated with improvement in the survival and deczeased PHC. Key words: Heart defects,congenital; Hypertension,pulmonary; Iloprost; Nitric oxide; Child