The Application Of Perioperative Inhaled Iloprost For Adoult Patients With Moderate/severe Pulmonary Artery Hypertension Secondary To Congenital Heart Disease

Background:Clinical experience suggests that pulmonary artery hypertension(PAH) is one of the common complications of left to right shunt congenital heart disease (CHD) and also a negative risk factor for outcome following surgical repairy in CHD. During the radical operation, the damage of cardiopulmonary bypass (CPB) on pulmonary vascular endothelium and reperfusion after CPB may increase the pulmonary pressure, which would make a volatility in hemodynamics and affact the surgery prognosis. We took some measures to reduce the intervention and disruption of surgery perioperative of CHD (particularly in pulmonary circulation), to these patients. We maintained the hemodyna mics in a stable level perioperative and improved the surgical results and prognosis.Objective:We used inhaled iloprost and nitroglycerin in patients with moderate/ severe PAH secondary to CHD in adults duirng the perioperative period, and the differences between iloprost and nitroglycerin in hemodynamics, prognosis and surgical effect were observed and recorded.Methods:Case inclusion criteria: Patients,who were older than 18 years, suffered from left to right shunt CHD, and preoperatively cardiac catheterization via the right pulmonary showing:mean pulmonary arterial pressure(MPAP)≥31mmHg, pulmonary vascular resistance(PVR)>240dyne·sec·cm-5, and pulmonary capillary wedge pressure (PCWP)≤15mmHg.Selected patients were divided into two groups randomly, respectively inhaled iloprost and nitroglycerin.All patients were given morphine 0.2mg/kg, phenergan 25mg, scopolamine 0.3mg preoperatively. Radial artery puncture was prepared for monitoring the arterial blood pressure before the induction of anesthesia ,and the six-cavity floating catheter was placed via the jugular vein or subclavian vein, from which we got hemodynamic parameters. For induction of anesthesia,midazolam 0.1-0.2mg/kg, Pipecuronium bromide 0.1-0.2mg/kg and fentanly10-15μg/kg were given. Mechanical ventilation went work after intubation.The VT was setted at 10-12ml/kg and oxygen concentration was controlled at 60-70% to make end-tidal carbon dioxide be maintained at 30-35mmHg. During the whole operation ,Fentanly maintain at the total of 30-50μg/kg,Pipecuronium bromide 0.1mg/kg/h, and also inhaled sevoflurane at 0.5%-2% interruptionly.Hemodynamic parameters should be recorded incluing: MPAP, PVR, systemic vascular resistance (SVR),mean blood pressure(MBP), cardiac output(CO), mixed venous oxygen saturation(SVO2),PCWP,center venous pressure(CVP),right ventricular end-diastolic-volume(RVEDV),right ventricular eject fraction(RVEF).Drug dose:iloprost 20μg/4ml, nitroglycerin 25μg/kg diluted to 4ml,and every inhalation holding for 10-15min/time.The two drugs were given at these 5 points:after inducement, when CPB ended,2h,6h and 12h postoperatively.And also,those hemodynamic parameters were recorded before and after each inhaling. And also the CPB time, operative time and the time stayed in ICU of each patient's were recorded.Results:There was no significant difference in preoperative general, CPB time and operation time between the two groups (P>0.05).The MPAP,PVR and RVEDV decreased significantly after inhalation iloprost than those in pre-inhalation baseline(P<0.05), and the CO and RVEF was significantly increased compared with before inhalation (P <0.05): the MPAP showed a significant decreace from (50.4±9.65) mmHg at the baseline to (32.2±7.45)mmHg, there was a same change in PVR,from (595.13±126.57) dynes·sec·cm-5at baseline reduced abviously to (427.66±130.95) dynes·sec·cm-5, and the CO after CPB also improved apparently, increased from (3.67±1.09) L/min to (4.78±1.23) L/min;the SVO2 from(68.23±1.73)% to(73.35±4.20)%;the RVEDV from(263.53±80.2)ml to(193.52±53.82)ml;the RVEF from (18.37±3.25)% to (27.35±4.85)%.The MPAP and PVR of nitroglycerin group decreased significantly after inhalation than those in pre-inhalation baseline (P<0.05),but the CO,RVEDV and RVEF got no significant change (P>0.05):the MPAP descended to (40.29±7.62) mmHg from (49.98±9.23) mmHg, and the PVR also made a falling from(595.93±126.57) dynes·sec·cm-5 to (517.67±88.92) dynes·sec·cm-5 responded to nitroglycerin, and the CO after CPB increased to (3.96±0.67) L/min from the (3.45±0.65) L/min; RVEF improved from(17.62±4.36)% to(23.11±4.62)%,and the RVED descended from(261.66±75.47)ml to(226.27±34.57)ml,SVO2 improved from(69.24±3.32)% to(72.46±3.13)%,We can see the changes of inhaled iloprost group are more significant than nitroglycerin,s(P<0.05).The MBP,SVR,HR,MAP,CVP and PCWP were rarely changed in all time (P>0.05). The Two groups of patients stayed in ICU respectively for (22.53±11.94) h (iloprost group) and (31.07±10.72) h (nitroglycerin group)separately( P <0.05).Conclusion: Inhaled iloprost can effectively and selectivity reduce the MPAP,PVRand RVEDV,and enhance the CO and RVEF obviously,from which we can see that inhaled iloprost aslo improved heart function in patients with moderate/severe pulmonary hypertension,but the systemic circulation be influenced rarely.So patients inhaled iloprost can savive the perioperative period safetly.So we convinceed that rational application of inhaled iloprost let down the pulmonary hypertension and improve the success rate of surgery,so it has great significance in improving the prognosis of the adult CHD with pulmonary hypertension. We think inhaled iloprost have a guiding role in the treatment of pulmonary hypertension secondary to CHD for adults.