title: Coronary versus carotid blood flow and coronary perfusion pressure in a pig model of prolonged cardiac arrest treated by different modes of venoarterial ECMO and intraaortic balloon counterpulsation.
abstract: BACKGROUND
  Extracorporeal membrane oxygenation (ECMO) is increasingly used in cardiac arrest (CA). Adequacy of carotid and coronary blood flows (CaBF, CoBF) and coronary perfusion pressure (CoPP) in ECMO treated CA is not well established. This study compares femoro-femoral (FF) to femoro-subclavian (FS) ECMO and intraaortic balloon counterpulsation (IABP) contribution based on CaBF, CoBF, CoPP, myocardial and brain oxygenation in experimental CA managed by ECMO.
  
  
  METHODS
  In 11 female pigs (50.3 ± 3.4 kg), CA was randomly treated by FF versus FS ECMO ± IABP. Animals under general anesthesia had undergone 15 minutes of ventricular fibrillation (VF) with ECMO flow of 5 to 10 mL/kg/min simulating low-flow CA followed by continued VF with ECMO flow of 100 mL/kg/min. CaBF and CoBF were measured by a Doppler flow wire, cerebral and peripheral oxygenation by near infrared spectroscopy. CoPP, myocardial oxygen metabolism and resuscitability were determined.
  
  
  RESULTS
  CaBF reached values > 80% of baseline in all regimens. CoBF > 80% was reached only by the FF ECMO, 90.0% (66.1, 98.6). Addition of IABP to FF ECMO decreased CoBF to 60.7% (55.1, 86.2) of baseline, P = 0.004. FS ECMO produced 70.0% (49.1, 113.2) of baseline CoBF, significantly lower than FF, P = 0.039. Addition of IABP to FS did not change the CoBF; however, it provided significantly higher flow, 76.7% (71.9, 111.2) of baseline, compared to FF + IABP, P = 0.026. Both brain and peripheral regional oxygen saturations decreased after induction of CA to 23% (15.0, 32.3) and 34% (23.5, 34.0), respectively, and normalized after ECMO institution. For brain saturations, all regimens reached values exceeding 80% of baseline, none of the comparisons between respective treatment approaches differed significantly. After a decline to 15 mmHg (9.5, 20.8) during CA, CoPP gradually rose with time to 68 mmHg (43.3, 84.0), P = 0 .003, with best recovery on FF ECMO. Resuscitability of the animals was high, both 5 and 60 minutes return of spontaneous circulation occured in eight animals (73%).
  
  
  CONCLUSIONS
  In a pig model of CA, both FF and FS ECMO assure adequate brain perfusion and oxygenation. FF ECMO offers better CoBF than FS ECMO. Addition of IABP to FF ECMO worsens CoBF. FF ECMO, more than FS ECMO, increases CoPP over time.
authors.affiliation: 2nd Department of Medicine - Department of Cardiovascular Medicine, First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, U Nemocnice 2, Prague 2, 128 00, Czech Republic. jan.belohlavek@vfn.cz
authors.forename: Jan
authors.initials: J
authors.lastname: Bělohlávek
authors.forename: Mikuláš
authors.initials: M
authors.lastname: Mlček
authors.forename: Michal
authors.initials: M
authors.lastname: Huptych
authors.forename: Tomáš
authors.initials: T
authors.lastname: Svoboda
authors.forename: Stěpán
authors.initials: S
authors.lastname: Havránek
authors.forename: Petr
authors.initials: P
authors.lastname: Ošt'ádal
authors.forename: Tomáš
authors.initials: T
authors.lastname: Bouček
authors.forename: Tomáš
authors.initials: T
authors.lastname: Kovárník
authors.forename: František
authors.initials: F
authors.lastname: Mlejnský
authors.forename: Vratislav
authors.initials: V
authors.lastname: Mrázek
authors.forename: Marek
authors.initials: M
authors.lastname: Bělohlávek
authors.forename: Michael
authors.initials: M
authors.lastname: Aschermann
authors.forename: Aleš
authors.initials: A
authors.lastname: Linhart
authors.forename: Otomar
authors.initials: O
authors.lastname: Kittnar
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D002339:Carotid Arteries / Q000502:physiology*; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000502:physiology*; D004195:Disease Models, Animal; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D005260:Female; D006323:Heart Arrest / Q000503:physiopathology*; D006439:Hemodynamics; D007423:Intra-Aortic Balloon Pumping; D011897:Random Allocation; D013552:Swine