Vasopressin decreases intestinal mucosal perfusion: a clinical study on cardiac surgery patients in vasodilatory shock.
BACKGROUND
Low to moderate doses of vasopressin have been used in the treatment of cathecholamine-dependent vasodilatory shock in sepsis or after cardiac surgery. We evaluated the effects of vasopressin on jejunal mucosal perfusion, gastric-arterial pCO2 gradient and the global splanchnic oxygen demand/supply relationship in patients with vasodilatory shock after cardiac surgery.


METHODS
Eight mechanically ventilated patients, dependent on norepinephrine to maintain mean arterial pressure (MAP) > or = 60 mmHg because of septic/post-cardiotomy vasodilatory shock and multiple organ failure after cardiac surgery, were included. Vasopressin was sequentially infused at 1.2, 2.4 and 4.8 U/h for 30-min periods. Norepinephrine was simultaneously decreased to maintain MAP at 75 mmHg. At each infusion rate of vasopressin, data on systemic hemodynamics, jejunal mucosal perfusion, jejunal mucosal hematocrit and red blood cell velocity (laser Doppler flowmetry) as well as gastric-arterial pCO2 gradient (gastric tonometry) and splanchnic oxygen and lactate extraction (hepatic vein catheter) were obtained.


RESULTS
The cardiac index, stroke volume index and systemic oxygen delivery decreased and systemic vascular resistance and systemic oxygen extraction increased significantly, while the heart rate or global oxygen consumption did not change with increasing vasopressin dose. Jejunal mucosal perfusion decreased and the arterial-gastric-mucosal pCO2 gradient increased, while splanchnic oxygen or lactate extraction or mixed venous-hepatic venous oxygen saturation gradient were not affected by increasing infusion rates of vasopressin.


CONCLUSIONS
Infusion of low to moderate doses of vasopressin in patients with norepinephrine-dependent vasodilatory shock after cardiac surgery induces an intestinal and gastric mucosal vasoconstriction.
Nygren
A
A
Department of Cardiothoracic Anesthesia and Intensive Care, Sahlgrenska University Hospital, Göteborg, Sweden.
Thorén
A
A
Ricksten
S-E
SE
D000368:Aged; D002245:Carbon Dioxide / Q000097:blood; D006348:Cardiac Surgical Procedures; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006490:Hemostatics / Q000627:therapeutic use*; D006801:Humans; D007413:Intestinal Mucosa / Q000098:blood supply*; D007583:Jejunum / Q000098:blood supply / Q000187:drug effects; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects; D011183:Postoperative Complications / Q000188:drug therapy*; D012039:Regional Blood Flow / Q000187:drug effects; D012769:Shock / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D013152:Splanchnic Circulation / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D014667:Vasopressins / Q000627:therapeutic use*
D006490:Hemostatics; D014667:Vasopressins; D002245:Carbon Dioxide