Effects Of Remifentanil On Haemodynamics And NPY In Infants Undergoing Congenital Heart Surgery For Left-to-Right Shunt Lesions During Induction

Objective:To investigate the effects of remifentanil on haemodynemics and neuropeptide Y(NPY) in infant undergoing congenital heart surgery for left to right shunt lesions during anaesthesitic induction, and to determine the optimum doses for infants,thus providing evidence for the clinical practace. Methods:Forty congenital heart desease infants undergoing ASD or VSD neoplasty requiring cardiopulmonary bypass(CPB )were selectived. They were randomized to enter in four different remifentanil groups (D1: 0.25 ug/kg , D2: 0.5 ug/kg, D3: 1.0 ug/kg,D4: 2.0 ug/kg) to receive anesthesia induction. Blood samples were obtained at T1 (before administration ) ,T2,T3,T4 (2,5 and 10 min after tracheal intubation) for blood gas analysis and plasma levels of NPY. HR,SBP,DBP were also recorded. Results:Haemodynemics: (l)Compared with before administration (Tl),there was no statistical significant changes of SBP,DBP,HR were identified(P>0.05) in infants of D1(0.25 ug/kg) and D2(0.5 ug/kg) groups.In group D3(1.0 ug/kg),there was reduced SBP,HR (p<0.01) at T2.In group D4(2.0 ug/kg) there was reduced SBP,DBP,HR (p<0.01) at T2 and T3.(2) No statistical significent changes of SBP,DBP,HR were identified(P>0.05) in infants of the four groups at T1.There was reduced SBP,DBP,HR(P<0.01) in group D3(1.0 ug/kg) and D4(2.0 ug/kg) compared with D1(0.25 ug/kg) and D2(0.5 ug/kg) groups at T2, and SBP,DBP,HR were obviously decreased (P<0.01) in group D4.However, SBP,DBP,HR were obviously decreased (P<0.01 ) in group D4 than other three groups at T3. One infant receiving lug/kg remifentanil need treated with metaradrine (50ug,iv) for severe hypotension(SBP<70mmHg), one minute later, blood presure advanced to 90/50mmHg. and three infants receiving 2ug/kg need treated with metaradrine (50-100ug,iv) for severe hypotension(SBP<70mmHg). Blood gas analysis: There was significant increase(P<0.01) of PaO₂ and decrease(P<0.01) of PaCO₂ in all infants after tracheal intubation,but no statistical significant changes of PH,SaO₂.NPY: (1)Compared with before administration (T1),there was no statistical significant changes of NPY were identified(P>0.05) in infants of D1(0.25 ug/kg) and D2(0.5 ug/kg) groups.In group D3(1.0 ug/kg),there was reduced NPY(p<0.05) at T2. In group D4(2.0 ug/kg) there was reduced NPY(p<0.01～0.05) at T2 and T3.(2) There was reduced NPY (P<0.01) in group D3(1.0 ug/kg) and D4(2.0 ug/kg) compared with D1(0.25 ug/kg) and D2(0.5 ug/kg) groups at T2, and NPY were obviously decreased (P<0.01 ) in group D4. However,there was no statistical significant changes(P>0.05) of NPY were identified in the four groups at T3 and T4. Conclusion:It is well feasibility to use remifentanil in infants undergoing congenital heart surgery for left to right shunt lesions during induction,the remifentanil doseages of 0.25 and 0.50ug/kg are fine. Suitable doseage of remifentanil and propofol for tracheal intubation without the use of muscle relaxants can suppress the Plasma NPY increase and maintain stable haemodynamics.