UWORLD NCLEX RATIONALES/INFORMATION TO KNOW-2021

Hypovolemic shock most commonly occurs from blood loss but can occur in any condition that reduces intravascular volume. Hypovolemia is classified as either an absolute (ex. hemorrhage, surgery, gastrointestinal bleeding, vomiting, diarrhea) or a relative (ex. pancreatitis, sepsis) fluid loss. Reduced intravascular volume results in decreased venous return, decreased stroke volume and cardiac output, inadequate tissue perfusion, and impaired cellular metabolism. Clinical manifestations of hypovolemic shock are associated with inadequate tissue perfusion and include: • Change in mental status • Tachycardia with thready pulse • Cool, clammy skin • Oliguria • Tachypnea Decreased urine output (0.5 mL/kg/hr) despite fluid replacement indicates inadequate tissue perfusion to the kidneys and is a manifestation of hypovolemic shock in a client with normal renal functionElevated estrogen levels (ex. oral contraceptive use, pregnancy, hormone replacement therapy) make blood hypercoagulable. However, elevated estrogen levels are more likely to form thrombi in veins than in arteries due to lower venous pressure and slower blood flow (ex. venous stasis). Unlike chronic venous insufficiency, in which vessels ineffectively return blood from the feet to the central circulation, standing is not a risk factor for PAD, as standing facilitates blood flow by gravity to the lower extremities. In peripheral artery disease, arteries in the extremities become atherosclerotic (progressive thickening and hardening due to chronic damage). Peripheral tissue perfusion is impaired, causing pain with exercise (ex. intermittent claudication) and at rest. Risk factors include hypertension, diabetes mellitus, hyperlipidemia, and smoking