title: Cardio-cerebral and metabolic effects of methylene blue in hypertonic sodium lactate during experimental cardiopulmonary resuscitation.
abstract: BACKGROUND
  Methylene blue (MB) administered with a hypertonic-hyperoncotic solution reduces the myocardial and cerebral damage due to ischaemia and reperfusion injury after experimental cardiac arrest and also increases short-term survival. As MB precipitates in hypertonic sodium chloride, an alternative mixture of methylene blue in hypertonic sodium lactate (MBL) was developed and investigated during and after cardiopulmonary resuscitation (CPR).
  
  
  METHODS
  Using an experimental pig model of cardiac arrest (12 min cardiac arrest and 8 min CPR) the cardio-cerebral and metabolic effects of MBL (n=10), MB in normal saline (MBS; n=10) or in hypertonic saline dextran (MBHSD; n=10) were compared. Haemodynamic variables and cerebral cortical blood flow (CCBF) were recorded. Biochemical markers of cerebral oxidative injury (8-iso-PGF2alpha), inflammation (15-keto-dihydro-PGF2alpha), and neuronal damage (protein S-100beta) were measured in blood from the sagittal sinus, whereas markers of myocardial injury, electrolytes, and lactate were measured in arterial plasma.
  
  
  RESULTS
  There were no differences between groups in survival, or in biochemical markers of cerebral injury. In contrast, the MBS group exhibited not only increased CKMB (P<0.001) and troponin I in comparison with MBHSD (P=0.019) and MBL (P=0.037), but also greater pulmonary capillary wedge pressure 120 min after return of spontaneous circulation (ROSC). Lactate administration had an alkalinizing effect started 120 min after ROSC.
  
  
  CONCLUSIONS
  Methylene blue in hypertonic sodium lactate may be used against reperfusion injury during experimental cardiac arrest, having similar effects as MB with hypertonic saline-dextran, but in addition better myocardial protection than MB with normal saline. The neuroprotective effects did not differ.
authors.affiliation: Department of Surgical Sciences/Anaesthesiology, Faculty of Medicine, Uppsala University, S-751 85 Uppsala, Sweden. adriana.miclescu@akademiska.se
authors.forename: Adriana
authors.initials: A
authors.lastname: Miclescu
authors.forename: Samar
authors.initials: S
authors.lastname: Basu
authors.forename: Lars
authors.initials: L
authors.lastname: Wiklund
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D002560:Cerebrovascular Circulation / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D006323:Heart Arrest / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy; D006982:Hypertonic Solutions / Q000008:administration & dosage; D008751:Methylene Blue / Q000008:administration & dosage / Q000494:pharmacology*; D009206:Myocardium / Q000378:metabolism; D019354:Sodium Lactate / Q000008:administration & dosage; D013552:Swine
chemical_list: D004791:Enzyme Inhibitors; D006982:Hypertonic Solutions; D008751:Methylene Blue; D019354:Sodium Lactate