title: Hypertonic saline hydroxyethylstarch restores right ventricular-arterial coupling after normovolemic hemodilution in piglets.
abstract: BACKGROUND
  Normovolemic hemodilution is known to inhibit hypoxic pulmonary vasoconstriction. How the coupling between the pulmonary arterial (PA) circulation and the right ventricle (RV) is affected by normovolemic hemodilution and by the composition of replacement solutions remains unknown. Therefore, the effects of isotonic and hypertonic saline hydroxyethylstarch solutions on the pulmonary circulation and RV, in control and hypoxic conditions, were compared.
  
  
  METHODS
  Anesthetized piglets (n = 14) were equipped with manometer-tipped catheters in the RV and main PA and an ultrasonic flow probe around the main PA. The pulmonary circulation was assessed by pressure-flow relations and vascular impedance, RV afterload by effective arterial elastance (Ea), RV contractility by end-systolic elastance (Ees), and RV-PA coupling by the Ees/Ea ratio. Measurements were done in control (Fio2 0.40) and hypoxic (Fio2 0.12) conditions before and after acute normovolemic hemodilution with either 20 ml/kg isotonic saline hydroxyethylstarch (hydroxyethylstarch 130/0.4 6% in NaCl 0.9%, Voluven, Fresenius-Kabi, Sevres, France) or 5 ml/kg hypertonic saline hydroxyethylstarch (hydroxyethylstarch 200/0.5 6% in NaCl 7.2%, HyperHES, Fresenius-Kabi) solutions.
  
  
  RESULTS
  Hypoxic pulmonary vasoconstriction was associated with proportional increases in Ea and Ees and did not affect RV-PA coupling. Hemodilution attenuated the hypoxic response. Hemodilution with isotonic saline hydroxyethylstarch did not affect the RV-PA coupling, whereas hemodilution with hypertonic saline hydroxyethylstarch increased Ees and the Ees/Ea ratio.
  
  
  CONCLUSIONS
  In experimental normovolemic hemodilution, both in control and in hypoxic conditions, RV-PA coupling is unaffected by isotonic saline hydroxyethylstarch but improved by hypertonic saline hydroxyethylstarch, mainly because of an increase in RV contractility.
authors.affiliation: Service d'Anesthésie-Réanimation Adultes, Hôpital La Timone, Marseille, France. francois.kerbaul@ap-hm.fr
authors.forename: François
authors.initials: F
authors.lastname: Kerbaul
authors.forename: Benoît
authors.initials: B
authors.lastname: Rondelet
authors.forename: Vincent
authors.initials: V
authors.lastname: Bénas
authors.forename: Dominique
authors.initials: D
authors.lastname: Grisoli
authors.forename: Arnaud
authors.initials: A
authors.lastname: De Waroquier
authors.forename: Pierre
authors.initials: P
authors.lastname: Fesler
authors.forename: Thierry
authors.initials: T
authors.lastname: Fusai
authors.forename: Serge
authors.initials: S
authors.lastname: Brimioulle
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects; D006438:Hemodilution; D006454:Hemoglobins / Q000378:metabolism; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D006982:Hypertonic Solutions / Q000494:pharmacology*; D000860:Hypoxia / Q000378:metabolism; D009200:Myocardial Contraction / Q000187:drug effects; D010952:Plasma Substitutes / Q000494:pharmacology*; D011652:Pulmonary Circulation / Q000502:physiology; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects; D016278:Ventricular Function, Right / Q000187:drug effects
chemical_list: D006454:Hemoglobins; D006895:Hydroxyethyl Starch Derivatives; D006982:Hypertonic Solutions; D010952:Plasma Substitutes