Catecholamines and splanchnic perfusion.

Abstract

For supportive therapy in sepsis adequate volume loading is probably the first, and possibly the most important step in the treatment of patients with septic shock. An elevated global O2-supply (DO2) may be necessary and beneficial in most of these patients, but the increase in DO2 should be guided by measurement of parameters assessing global and regional oxygenation. Routine strategies for elevating DO2 by the use of very high dosages of catecholamines cannot be recommended. Vasopressors should be used to achieve adequate perfusion pressure. With noradrenaline, no negative effects on regional perfusion have been demonstrated when the patient is adequately volume-resuscitated and the DO2 is normal or even slightly elevated. In contrast, adrenaline should be avoided because it appears to redistribute blood flow away from the splanchnic region. There is controversy as to whether dopamine should still be used as a first-line drug in patients with septic shock, since some clinical and experimental data indicate unfavourable effects on mucosal perfusion of the gut. To date there are no convincing data to support the routine use of low-dose dopamine or dopexamine in patients with sepsis. Neither low-dose dopamine nor dopexamine have been proved to prevent renal failure in septic patients. Furthermore, there is evidence that low-dose dopamine may reduce mucosal perfusion in the gut in some patients. Dopexamine has been suggested for improvement of splanchnic perfusion, but since these effects remain somewhat controversial there are no current grounds for a general recommendation in favour of dopexamine in septic patients. These recommendations are currently limited by the lack of sufficient outcome studies and studies evaluating regional perfusion. Until the various catecholamine regimes are more fully examined, recommendations for catecholamine support in sepsis must be considered "conditional".