Sepsis is more common and more dangerous in elderly persons, individuals with a compromised immune system, and persons who are already critically ill. Patients with sepsis require prompt medical attention and are usually treated in the intensive care unit with intravenous fluids and antibiotics. Due to complications of sepsis, patients may need specific medications to maintain blood pressure, and artificial ventilation or dialysis may be needed to support function of the lungs or kidneys. Central venous catheters (tubes) and arterial catheters may be needed to help guide therapy. Patients with sepsis require preventive measures for deep vein thrombosis, stress ulcers, and pressure ulcers. Mortality rates are high, with 20% for sepsis, 40% for severe sepsis, and more than 60% for septic shock. Those who recover may have some permanent organ damage. Recently, physicians have been using activated protein C (a natural protein that inhibits inflammation) to treat some cases of severe sepsis and septic shock. Overall, it reduces risk of dying of severe sepsis slightly, but it increases the risk of bleeding, is expensive, and many patients do not benefit from it.