Circulatory optimization of the patient with or at risk for shock

Prevention of Acute Renal Failure: Role of Vaso-Active Drugs, Mannitol and Diuretics

Evidence exists that acute renal failure (ARF) independently increases mortality risk in critically-ill patients. Therefore prevention of ARF seems of paramount importance. Preservation of renal blood flow and (sufficient) perfusion pressure favourably influences the prevention of renal function deterioration in the critically-ill septic patient. The first step to achieve this is infusion of fluids, either crystalloids or colloids, with the aim of optimal fluid resuscitation. Although “optimal fluid resuscitation” is poorly defined, in clinical practice it can be considered as the point where a certain preload is obtained, after which no further increase of cardiac output is observed with further fluid infusion. Vasoactive drugs can be added to this regimen in case of insufficient restoration of flow and especially perfusion pressure. The addition of norepinephrine can be of value if high doses of dopamine fail to restore perfusion pressure. No evidence exists that low-dose dopamine prevents renal failure and, therefore, dopamine should not be given for this indication. The use of diuretic agents can be harmful, as indicated by observational and cohort studies. Although mannitol flushes out intratubular casts and increases tubular flow, which is favorable in myoglobinuria or hemoglobinuria, so far no well designed clinical studies have demonstrated its efficacy in ARF. In conclusion, there is currently no convincing evidence for any benefit from diuretic agents and/or (low dose) dopamine in the prevention of ARF. High quality intenisve care and avoidance of harm is, therefore, the current standard of the prevention of ARF.

Pharmacological treatment of sepsis

The incidence of sepsis, the combination of a systemic inflammatory response syndrome and documented infection, is as high as up to 95 cases per 100,000 people per year. The understanding of the pathophysiology of sepsis has much increased over the last 20 years. However, sepsis combined with shock is still associated with a high mortality rate varying from 35 to 55%. Causative treatment, source control and antibiotics started as soon as possible, are the cornerstone of therapy in combination with symptomatic treatment in the ICU. The pharmacological interventions, including fluid resuscitation, vasoactive drugs and adjunctive drugs such as steroids, activated protein C are discussed. The possible beneficial role of strict glucose control is also addressed. Since many drug intervention studies were negative, lessons should be learned from earlier experiences for future trials. Source control and level of intensive care should be eliminated as confounders.