title: [Effects of extracorporeal membrane oxygenation on hemodynamics in acute right heart failure in dogs].
abstract: OBJECTIVE
  To investigate the effects of extracorporeal membrane oxygenation (ECMO) on the hemodynamics in dogs with acute right heart failure.
  
  
  METHODS
  Ten healthy adult male dogs (weighted 20-25 kg) were randomly divided into two groups: acute right heart failure group (n = 5) and ECMO group (n = 5). Under anesthesia, dogs  were underwent thoracotomy, then the catheters were placed in the right atrium, right ventricle, and pulmonary artery, for measuring the relevant pressures, including right arterial pressure (RAP), right ventricular pressure (RVP), and pulmonary artery pressure (PAP). The vascular ultrasound probe were placed on the aorta and pulmonary artery for measuring the cardiac output (CO) and pulmonary artery flow rate (QPA). Then, a baseline measurement was acquired. The femoral artery and femoral vein were cannulated and used for the venoarterial extracorporeal membrane oxygenation (VA-ECMO), and then connected to extracorporeal circuit, which was initially primed. The pulmonary artery was progressively ligated to decrease blood flow until QPA was 60%, 40%, and 0% of baseline in both groups. The above flow conditions were respectively maintained for 30 minutes, after which hemodynamic data were collected.
  
  
  RESULTS
  The baseline hemodynamic measurements were not different between acute right heart failure group and ECMO group. After ligating the pulmonary artery, compared with baseline, CO (L/min) decreased significantly at 60% and 40% QPA in acute right heart failure group (1.80 ± 0.19, 1.48 ± 0.22  vs.  3.24 ± 0.23, both P < 0.05), and significantly lower than that of ECMO group (60%QPA: 1.80 ± 0.19  vs.  3.24 ± 0.35; 40%QPA: 1.48 ± 0.22  vs.  3.20 ± 0.37, both P < 0.05). CO was not significantly different from baseline in ECMO group at 60%, 40% and 0% QPA (3.24 ± 0.35, 3.20 ± 0.37, 3.12 ± 0.28  vs.  3.44 ± 0.32, all P>0.05). PAP, RAP and RVP (all mm Hg, 1 mm Hg = 0.133 kPa) were significantly elevated in acute right heart failure group at 60% and 40% QPA compared with baseline (PAP: 36.2 ± 5.3, 39.8 ± 5.4  vs.  17.4 ± 2.7; RAP: 11.2 ± 2.8, 12.8 ± 2.6  vs.  4.4 ± 1.7; RVP: 25.6 ± 4.9, 27.8 ± 4.5  vs.  11.6 ± 1.8, all P < 0.05), and significantly higher than those of ECMO group (60%QPA: PAP 36.2 ± 5.3  vs.  23.2 ± 5.2, RAP 11.2 ± 2.8  vs.  6.2 ± 2.3, RVP 25.6 ± 4.9  vs.  15.2 ± 3.5; 40%QPA: PAP 39.8 ± 5.4  vs.  24.4 ± 4.8, RAP 12.8 ± 2.6  vs.  7.0 ± 2.4, RVP 27.8 ± 4.5  vs.  16.8 ± 4.2, all P < 0.05), whereas mean artery pressure (MAP, mm Hg) was significantly lowered compared with that of baseline (81.2 ± 15.8, 62.2 ± 14.4  vs.  128.6 ± 16.4, both P < 0.05), and it was lower than that of ECMO group (60%QPA: 81.2 ± 15.8  vs.  128.0 ± 26.5; 40%QPA: 62.2 ± 14.4  vs.  124.6 ± 25.4, both P < 0.05). At 60%, 40% and 0% QPA in ECMO group, whereas heart rate (HR, beats/min), PAP, RAP and RVP were slightly increased compared with those of baseline (HR: 161.4 ± 14.8, 160.6 ± 13.1, 157.6 ± 11.9  vs.  152.6 ± 14.5; PAP: 23.2 ± 5.2, 24.4 ± 4.8, 25.2 ± 6.2  vs.  18.8 ± 3.4; RAP: 6.2 ± 2.3, 7.0 ± 2.4, 7.6 ± 4.2  vs.  4.6 ± 1.5; RVP: 15.2 ± 3.5, 16.8 ± 4.2, 16.2 ± 3.3  vs.  12.2 ± 2.3), but MAP was slightly decreased (128.0 ± 26.5, 124.6 ± 25.4, 121.2 ± 21.4  vs.  135.8 ± 22.2), however, all differences were not statistically significant (all P>0.05).
  
  
  CONCLUSIONS
  These findings demonstrate that VA-ECMO could be helpful in improving cardiac function, and maintaining stability of hemodynamics in dogs with acute right heart failure.
authors.affiliation: Intensive Care Unit, the Second Affiliated Hospital of Harbin Medical University, Harbin 150086, Heilongjiang, China.
authors.forename: Jun-bo
authors.initials: JB
authors.lastname: Zheng
authors.forename: Kai-jiang
authors.initials: KJ
authors.lastname: Yu
authors.forename: Ming
authors.initials: M
authors.lastname: Ye
authors.forename: Hong-liang
authors.initials: HL
authors.lastname: Wang
authors.forename: Xue-song
authors.initials: XS
authors.lastname: Jiang
authors.forename: Hai-tao
authors.initials: HT
authors.lastname: Liu
mesh_terms: D000818:Animals; D004285:Dogs; D015199:Extracorporeal Membrane Oxygenation; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006439:Hemodynamics; D008297:Male; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology / Q000628:therapy