Hypovolemic Shock Nursing Care Management and Study Guide

In hypovolemic shock, reduced intravascular volume drops cardiac output and starves tissues of perfusion. On the floor your job is early recognition (hypotension with narrowed pulse pressure, tachycardia, oliguria, cool clammy skin), rapid volume replacement, controlling the source of loss, and watching for the organ failure that follows. Catch it before compensation breaks down.

What is Hypovolemic Shock?

Reduced intravascular blood volume causes circulatory dysfunction and inadequate tissue perfusion. Vascular fluid loss drives extreme tissue hypoperfusion.

Pathophysiology

Fluid loss, internal or external, drops arterial blood pressure and triggers compensatory mechanisms that try to restore intravascular volume. Falling pressure diminishes venous return, which reduces preload (filling pressure) and lowers stroke volume. Cardiac output falls with stroke volume, and mean arterial pressure drops as cardiac output declines. As perfusion falls, oxygen and nutrient delivery to the cells decreases, which can end in multiple organ dysfunction syndrome.

Causes

Hypovolemic shock usually results from acute blood loss of about one-fifth of total volume. Internal losses come from hemorrhage or third-space fluid shifting. External losses come from severe bleeding, diarrhea, diuresis, or vomiting. Inadequate vascular volume drops venous return and cardiac output.

Clinical Manifestations

Hypovolemic shock produces hypotension with a narrowed pulse pressure and decreased sensorium. The body compensates with tachycardia and with rapid, shallow respirations as oxygen delivery falls. Urine output drops below 25 mL/hour, and the skin turns cool, clammy, and pale.

Prevention

Recognize patients whose conditions reduce blood volume as at-risk. Keep accurate intake and output, estimate fluid loss, and replace it to prevent shock.

Complications

Untreated shock leads to acute respiratory distress syndrome (fluid building in the alveoli), acute tubular necrosis (tubule cell damage progressing to acute kidney failure), disseminated intravascular coagulation (widespread clotting cascade activation forming clots in small vessels), and multiple organ dysfunction syndrome as the end result.

Assessment and Diagnostic Findings

No single symptom or test establishes the diagnosis or severity. Labs show elevated potassium, serum lactate, and BUN. Urine specific gravity and osmolality are increased. Blood gases show decreased pH and partial pressure of oxygen with increased partial pressure of carbon dioxide.

Medical Management

Emergency treatment is prompt, adequate fluid and blood replacement to restore intravascular volume and raise blood pressure. Saline or lactated Ringer's solution, then possibly plasma proteins or other plasma expanders, provides volume until whole blood can be matched. A pneumatic antishock garment counters bleeding and hypovolemia by slowing arterial bleeding, forcing available blood from the lower body to the brain, heart, and vital organs, and preventing pooling in the legs. Treat the underlying cause: stop hemorrhage, or give medication for diarrhea or vomiting. Position the patient to assist fluid redistribution; modified Trendelenburg is recommended in hypovolemic shock.

Pharmacologic Therapy

If fluids fail to reverse the shock, give vasoactive drugs to prevent cardiac failure. Insulin is given if dehydration is secondary to hyperglycemia, and desmopressin (DDAVP) for diabetes insipidus. Antidiarrheal drugs are given for dehydration from diarrhea, and antiemetics for vomiting.

Nursing Management

Primary prevention of shock is the essential focus.

Nursing Assessment

History is vital for identifying causes and guiding the workup. Note vital signs taken before arrival at the emergency department. In trauma, determine the mechanism of injury and any detail that raises suspicion for specific injuries.

Nursing Diagnosis

Common diagnoses include risk for metabolic acidosis related to decreased capillary blood, deficient fluid volume related to active fluid loss, ineffective tissue perfusion, self-care deficit related to physical weakness, and anxiety.

Nursing Care Planning & Goals

Goals: maintain fluid volume at a functional level, report understanding of the causes of fluid volume deficit, maintain normal blood pressure, temperature, and pulse, and maintain elastic skin turgor, moist tongue and mucous membranes, and orientation to person, place, and time.

Nursing Interventions

For safe blood administration, draw specimens quickly, obtain a baseline CBC, and type and crossmatch in anticipation of transfusion. For safe fluid administration, monitor closely for cardiovascular overload, difficulty breathing, pulmonary edema, jugular vein distention, and abnormal labs. Monitor daily weight for sudden decreases, especially with falling urine output or active loss. Monitor vital signs every 15 minutes to 1 hour for the unstable patient and every 4 hours for the stable patient. Give oxygen to increase the amount carried by available hemoglobin.

Evaluation

Expected outcomes: maintained fluid volume at a functional level, reported understanding of the causes of fluid volume deficit, maintained normal blood pressure, temperature, and pulse, and maintained elastic skin turgor, moist tongue and mucous membranes, and orientation to person, place, and time.

Documentation Guidelines

Document the degree of deficit and current sources of fluid intake; intake and output, fluid balance, weight changes, edema, urine specific gravity, and vital signs; diagnostic results; functional level and limitations; needed resources and adaptive devices; availability and use of community resources; the plan and teaching plan; patient responses to interventions and teaching; progress toward outcomes; and modifications to the plan.