Effects of different volume therapies on hemodynamics and oxygen supply-demand balance in pigs after pulmonary lobectomy

Objective To observe the effects of three different volume therapies on hemodynamics and oxygenation in pigs after pulmonary lobectomy,so as to provide evidence for clinical volume management.Methods Twenty adult Guizhou miniature pigs were randomly assigned to 3 groups: volume restriction group(group S,n=7),normal volume group(group M,n=6) and volume expansion group(group L,n=7).Group S received continuous Ringer's solution administration(5 mL·kg-1·h-1);group M requirement was determined according to basic requirement,preoperative fast,intraoperative loss and third space loss.The basic requirement and preoperative fast were administered with Ringer's solution according to rule 4-2-1.The third space loss was adminstered with Ringer's solution at 5 mL·kg-1·h-1.Group L was administered with of hydroxyethyl starch 130/0.4(Voluven) at 10 mL·kg-1·h-1 in addition to the regimen of M group.Perioperative hemodynamics data were recorded at 10 min after invasive operation(T1),one-lung ventilation 1 hour(T2),one-lung ventilation 2 hour(T3),one-lung ventilation 3 hour(T4) and resumption of bilateral pulmonary ventilation 1 hour(T5).Arterial and venous blood gas parameters were determined,and the oxygen supply(DO2) and oxygen consumption(VO2) were calculated.Results Heart rate(HR) in group L was increased at T3-T5 compared with that at T1(all P0.05);and central venous pressare(CVP),cardiac index(CI) were increased at T2-T5 compared with that at T1(P0.05,0.01);pulmonary artery pressure(PAP) was increased at T4-T5 compared with that at T1(all P0.05);and systemic vascular resistance(SVR) was decreased at T3-T5 compared with that at T1(P0.05,0.01).Mean arterial pressure(MAP) at T2-T4 in group L was significantly higher than that of group M(P0.05,0.01);CVP and CI at T2-T5 was significantly higher than those of group M(P0.05,0.01);PAP at T4-T5 was significantly higher than that of Group M(P0.05,0.01);and CI at T2-T5 was significantly higher than that of Group M(P0.05,0.01).MAP,CVP,PAP,and CI at T2-T5 in group L were significantly higher than those of group S(P0.05,0.01);SVR at T3-T5 was significantly lower than that of group S(P0.05,0.01).Pressure of oxygen in arterial blood(PaO2) at T2-T5 in group L was markedly lower than that at T1,and that in group L at T5 was significantly lower than those in group S and M(P0.05,0.01).PaO2 at T2-T4 in group S and M was significantly lower than that at T1(P0.05,0.01).DO2 at T2-T5 in group L was significantly higher than that at T1(P0.05,0.01).Conclusion Both volume restriction and normal volume therapies can maintain the stability of Hemodynamics and oxygen supply-demand balance in healthy pigs receiving pulmonary lobectomy.Volume expansion therapy may lead to hyperfunction in circulation and lung tissue oxygenation dysfunction after fluid infusion.