Oxygenation & Perfusion: Hypovolemic Shock
Pathophysiology/Causes
Risk Factors
Labs/Diagnostics
Complications
Collaborative Treatment
Symptoms
Tachycardia
Thirst
Rapid shallow respirations
Etiology: Loss of fluid volume externally (trauma, surgery) or internally (hemorrhage, burns)
Fluid replacement therapy
Large amounts of crystalloid solutions (LR, NS)
Blood products
Albumin
Treat underlying causes
Stop bleeding, rehydration, medications for N/V/D
Position in modified Trendelenburg (passive leg raising) to promote venous blood return
Oxygen therapy to maintain O2 concentration in remaining volume
External or internal fluid loss causes decreased intravascular volume
Venous return to heart is impaired. Decreases ventricular filling, stroke volume, and cardiac output. Arterial pressure decreases in response to lower CO and hypotension occurs.
Baroreceptors on aorta detect decreased pressure, activates sympathetic nervous system to compensate. Release of catecholamines, vasopressin, and RAAS activation.
Decreased systemic fluid volume and sympathetic diversion of blood from nonessential organs causes hypoperfusion of tissues. Hypoxic cells switch to anaerobic metabolism in absence of oxygen. Release of lactic acid causes metabolic acidosis as blood pH decreases.
Peripheral vasoconstriction to increase venous tone, increases BP to maintain vascular resistance against remaining fluid volume. Capillary damage and vascular leakage causes tissue edema and circulatory stasis.
HR and contractility increase to help heart meet workload demands. Impaired ventricular filling worsens SV and CO, further exacerbating cardiac workload until failure occurs.
Impaired tissue perfusion & hypoxia
Cyanosis
Anxious --> Confusion
Hypotension
Cells death occurs due to lack of oxygen and impaired metabolism, releases toxic components into circulation. Organs are dysfunctional as a result of cell death. Loss of compensatory measures leads to hemodynamic instability, progresses to multiorgan failure and death.
Infants and elderly are sensitive to fluid volume depletion and may refuse fluids
Decreased urine output
Kidney disease causing impaired reabsorption of salt and water, loss of fluid through urine
Cool extremities, delayed cap refill
Patients with trauma, injury, burns or postsurgical
ABGs consistent with metabolic acidosis (can be alkalotic too)
Lactate levels from lactic acid release by cells
Electrolytes showing sodium and potassium imbalances (high or low)
Cross-match blood in preparation for transfusion
Increased BUN, creatinine due to kidney failure
Prothrombin time to assess coagulopathy
CBCs alterations -- low hematocrit and hemoglobin due to hemorrhage, or hemoconcentration of blood components from fluid loss causes high values
Renal failure
Acute respiratory distress syndrome (ARDS)
Multiple organ dysfunction syndrome