title: Failure of nitroglycerin (glyceryl trinitrate) to improve villi hypoperfusion in endotoxaemic shock in sheep.
abstract: OBJECTIVE
  To evaluate the effects of nitroglycerin (glyceryl trinitrate) on intestinal microcirculation during endotoxaemic shock.
  
  
  METHODS
  Controlled experimental study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  20 anaesthetised, mechanically ventilated sheep.
  
  
  METHODS
  Septic shock was induced by endotoxin infusion. After 60 minutes without resuscitation, sheep received fluid resuscitation and were randomised to control or nitroglycerin groups. Nitroglycerin was infused at a rate of 0.2 µg/kg/min for 90 minutes.
  
  
  METHODS
  Improved villi microcirculation.
  
  
  RESULTS
  Endotoxin lowered arterial blood pressure, cardiac output and intestinal blood flow, which were improved by fluid resuscitation. Mean (SD) ileal intramucosal-arterial PCO2 gradient increased during shock and remained elevated after resuscitation in control and nitroglycerin groups (8 [8], 15 [9] and 17 [9], and 6 [6], 13 [11] and 14 [9]mmHg, respectively; P < 0.05, baseline v shock and resuscitation for both groups). Villi microvascular flow index was reduced during shock and remained lower than baseline after the resuscitation in both groups (3.0 [0.0], 2.5 [0.2] and 2.7 [0.2], and 3.0 [0.0], 2.3 [0.3] and 2.6 [0.3], respectively; P < 0.05, baseline v shock and resuscitation for both groups). The red blood cell velocity behaved similarly (859 [443], 553 [236] and 670 [276], and 886 [440], 447 [124] and 606 [235] µm/s, respectively; P < 0.05, baseline v shock and resuscitation for both groups).
  
  
  CONCLUSIONS
  In endotoxaemic sheep, low doses of nitroglycerin failed to improve the subtle but persistent villi hypoperfusion that remains present after fluid resuscitation.
authors: Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina.
authors: Vanina S Kanoore
authors: VS
authors: Edul
authors: Gonzalo
authors: G
authors: Ferrara
authors: Mario O
authors: MO
authors: Pozo
authors: Gastón
authors: G
authors: Murias
authors: Enrique
authors: E
authors: Martins
authors: Carlos
authors: C
authors: Canullén
authors: Héctor S
authors: HS
authors: Canales
authors: Elisa
authors: E
authors: Estenssoro
authors: Can
authors: C
authors: Ince
authors: Arnaldo
authors: A
authors: Dubin
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D006439:Hemodynamics; D019344:Lactic Acid / Q000097:blood; D008833:Microcirculation; D009569:Nitric Oxide / Q000502:physiology; D005996:Nitroglycerin / Q000627:therapeutic use*; D012756:Sheep; D012772:Shock, Septic; D014655:Vascular Resistance / Q000502:physiology; D014665:Vasodilator Agents / Q000627:therapeutic use*
chemical_list: D014665:Vasodilator Agents; D009569:Nitric Oxide; D019344:Lactic Acid; D005996:Nitroglycerin