Hypovolemic/Hemorrhagic Shock

DRG Category:	640
Mean LOS:	4.7 days
Description:	MEDICAL: Nutritional and Miscellaneous Metabolic Disorders With Major CC

Hypovolemic shock results from a decreased effective circulating volume of water, plasma, or whole blood and is the most common type of shock in adults and children. External, sudden blood loss resulting from penetrating trauma and severe gastrointestinal bleeding are common causes of hemorrhagic shock. A significant loss of greater than 30% of circulating volume results in a decrease in venous return, which in turn diminishes cardiac output, decreases perfusion to vital organs, and causes the symptoms associated with shock. When there is insufficient oxygen available to the cells, metabolism shifts from aerobic to anaerobic pathways. In this process, lactic acid accumulates in the tissues, and the patient develops metabolic acidosis. In addition, the tissues do not receive adequate glucose, and they cannot accomplish the removal of carbon dioxide. This disruption in normal tissue metabolism results initially in cellular destruction and, if left uncorrected, death. Significant hypovolemic shock (< 40% loss of circulating volume) lasting several hours or more is associated with a fatal outcome.

The American College of Surgeons separates hypovolemic/hemorrhagic shock into four classifications: Stage I occurs when up to 15% of the circulating volume, or approximately 750 mL of blood, is lost. These patients often exhibit few symptoms because compensatory mechanisms support bodily functions. Stage II occurs when 15% to 30%, or up to 1,500 mL of blood, of the circulating volume is lost. These patients have subtle signs of shock, but vital signs usually remain normal. Stage III occurs when 30% to 40% of the circulating volume, or from 1,500 to 2,000 mL of blood, is lost. This patient looks acutely ill. The most severe form of hypovolemic/hemorrhagic shock is stage IV. This patient has lost more than 40% of circulating volume, or least 2,000 mL of blood, and is at risk for exsanguination. Complications of hypovolemic shock include adult respiratory distress syndrome, sepsis, acute renal failure, disseminated intravascular coagulation, cerebrovascular accident, and multiple organ dysfunction syndrome.

Causes

The loss of circulating volume can result from a number of conditions. Hemorrhage caused by active blood loss that results from trauma is a frequent source of hypovolemia. Active bleeding or rupture of internal organs, such as the bowel or the fallopian tube when caused by an ectopic pregnancy, can quickly result in hypovolemia even without obvious bleeding. Profound decreases in circulating fluid volume can be caused by the plasma shifts seen in burns and ascites. Other sources of hypovolemia include decreases in fluid intake (dehydration) and increases in fluid output (vomiting, diarrhea, excessive nasogastric drainage, draining wounds, and diaphoresis). Excessive diuresis from diuretic overuse, diabetic ketoacidosis, and diabetes insipidus can also cause hypovolemia. Pregnancy-related disorders that can lead to hypovolemic shock include ruptured ectopic pregnancy, placenta previa, and abruption of the placenta.

Genetic considerations

No clear genetic contributions to susceptibility have been defined.

Gender, ethnic/racial, and life span considerations

Hypovolemic shock can occur at any age and in both sexes. Chronic illness can alter an individual’s compensatory abilities in the setting of hypovolemia. The most common cause of hypovolemic shock in children and elders is dehydration. In comparison, although trauma can occur at any age, in young adults the major cause of hypovolemic shock is hemorrhage from multiple trauma. Hypovolemic shock related to an ectopic pregnancy is fairly common in females of childbearing age, and gastrointestinal bleeding disorders are common in adults. There are no specific racial and ethnic considerations.

Global health considerations

The World Health Organization has identified motor vehicle crashes (MVCs) as a growing epidemic in developing regions of the world. Both blunt and penetrating traumatic injury resulting in excessive bleeding can result from MVCs. In regions at war or with civil or political strife, traumatic injuries also lead to hemorrhagic shock. Gastrointestinal bleeding is a source of hypovolemic/hemorrhagic shock around the world.

Assessment

History

If the patient is actively bleeding or is severely compromised, the history, assessment, and early management merge together into the primary survey. The primary survey is a rapid (30- to 60-second) head-to-toe assessment that encompasses the emergency management of threats to airway, breathing, and circulation (ABCs) or life. If the patient’s condition is stable enough to warrant a separate history, ask questions about allergies, current medications, preexisting medical conditions, and the factors that surround the hypovolemic/hemorrhagic condition.

Generally, patients who are experiencing hypovolemia because of trauma have either obvious bleeding or a history of injury to a vascularized area. Elicit information from the patient, emergency medical personnel, or the family as to how much blood was lost or how long the bleeding has continued. In the case of traumatic blood loss, it is important to remember that the most obvious injury site may not be the cause of the evolving hypovolemic shock.

Explore the possibility of a mechanism of injury, such as a burn or crush injury, leading to plasma fluid shifts extravascularly. Likewise, a history of either recent alterations in fluid volume intake or excessive loss—as in vomiting, diarrhea, excessive diaphoresis, or diuresis—is a potential indicator. In addition, obtain a subjective history of thirst, lethargy, and decreased urinary output.

Physical examination

Early signs include restlessness, anxiety, agitation, confusion, weakness, lightheadedness, and tachycardia. The patient may appear either stable and alert or critically ill depending on the phase of hypovolemic shock. If the patient can maintain the ABCs, assess the patient’s level of consciousness. Mental status changes may be indicators of diminished cerebral perfusion and are among the early signs of hypovolemic shock. Other early indicators include a decreased urinary output of less than 30 mL/hour, delayed capillary blanching, and signs of sympathetic nervous system stimulation (tachycardia, piloerection [gooseflesh]). Monitor vital signs, including heart and respiratory rate, blood pressure, and temperature. Changes in blood pressure (particularly hypotension) are a late rather than an early sign; pulse pressure, however, does initially widen and then narrow in the first two stages of shock. Orthostatic blood pressure changes also indicate hypovolemia. Inspect the patient’s neck veins and palpate them for the quality of carotid pulse and neck vein appearance. Inspect the patient’s abdomen for possible sites of fluid loss or compartmenting.

Percuss the chest and lung fields for the presence of fluid. Auscultate the patient’s bilateral breathing and note the patient’s respiratory effort. Auscultate the patient’s heart and note any new murmurs or other adventitious heart sounds. When you auscultate the patient’s abdomen, note the absence of bowel sounds, which may indicate a paralytic ileus, internal gastrointestinal bleeding, or peritonitis. If bowel sounds are hypoactive, bleeding may be causing blood to shunt to other more vital organs. Palpate the patient’s peripheral pulses and note signs of decreased blood flow and inadequate tissue perfusion (cold, clammy skin; weak, rapid pulses; delayed capillary refill), but remember that these signs are late indicators of hypovolemic shock and may not be present until the patient reaches stage III.

Four areas are considered to be life-threatening: (1) chest (auscultate for decreased breath sounds), (2) abdomen (examine for tenderness or distention), (3) thighs (check for deformities and bleeding into soft tissues), and (4) external bleeding.

Psychosocial

If the patient has a decreased level of consciousness, attempt to identify a family member or significant other to discuss the patient’s psychosocial history. Expect family members to be frightened, anxious, and in need of support. Of particular concern are the parents of young trauma patients who have to deal with a sudden, life-threatening event that may lead to the death of a child. Spouses of critically injured patients deal with role reversals, economic crises, and the fear of loss. Expect the family and partner of critically injured patients to express a range of emotions from fear and anxiety to grief and guilt.

Diagnostic highlights

General Comments: No one specific diagnostic test identifies the degree of hypovolemic shock state. Several laboratory indicators do provide valuable information on the status of the patient, however. These include arterial blood gases, hemodynamic parameters (cardiac output and cardiac index, oxygen delivery, oxygen consumption, central venous pressure, pulmonary capillary wedge pressure, and systemic vascular resistance), blood lactate level, hemoglobin, and hematocrit. Radiographic and imaging studies are important depending on the location of interest and might include chest and abdominal x-rays, transesophageal echocardiography, aortography, computed tomography, magnetic resonance imaging, or focused abdominal sonography for trauma. A pregnancy test should be completed for females of childbearing years, and if positive, followed by pelvic sonography.

Primary nursing diagnosis

Diagnosis

Fluid volume deficit related to active bleeding or fluid loss

Outcomes

Fluid balance; Circulation status; Cardiac pump effectiveness; Hydration

Interventions

Bleeding reduction; Fluid resuscitation; Blood product administration; Intravenous (IV) therapy; Circulatory care; Shock management

Planning and implementation

Collaborative

The initial care of the patient with hypovolemic shock follows the ABCs of resuscitation. Measures to ensure adequate oxygenation and tissue perfusion include establishing an effective airway and a supplemental oxygen source, controlling the source of blood loss, and replacing intravascular volume. The American College of Surgeons recommends crystalloid fluids such as normal saline solution or lactated Ringer’s solution for stages I and II and crystalloids plus blood products for stages III and IV. Although vasopressors, such as norepinephrine or dopamine, do increase blood pressure in the setting of hypovolemic shock, they should never be started if there is insufficient intravascular fluid or if tissues remain underperfused despite an adequate blood pressure.

The objective of fluid replacement is to provide for adequate cardiac output to perfuse the tissues. Generally, any fluid transiently improves perfusion, but only red blood cells (RBCs) can carry enough oxygen to maintain cellular function. Three milliliters of crystalloid solutions should be infused for every 1 mL of blood loss. It is currently recommended to use caution in replacing fluids after trauma because the low flow state may protect the patient from further bleeding until the traumatic injury is repaired. After repair, fluid resuscitation can be used aggressively. RBCs or whole blood should be considered when fluid resuscitation with crystalloids is not successful. RBCs are preferred because they contain an increased percentage of hemoglobin per volume. Type-specific blood is preferred, although O-negative blood can be used if type-specific blood is not immediately available.

Pharmacologic highlights

Medication or Drug Class	Dosage	Description	Rationale
Somatostatin (Zecnil)	250 mcg IV bolus, followed by a 250–500 mcg/hr continuous infusion; maintain for 2–5 days	Naturally occurring peptide from hypothalamus, gastrointestinal tract, and pancreas	Increases reabsorption of water from the kidney tubules

Other Drugs: Octreotide (Sandostatin)

Independent

After initial stabilization of airway and breathing, the most important nursing intervention is to ensure timely fluid replacement. Fluid resuscitation is most efficient through a short, large-bore peripheral IV catheter in a large peripheral vein. The IV line should have a short length of tubing from the bag or bottle to the IV site. If pressure is applied to the bag, fluid resuscitation occurs more rapidly. If fluids can be warmed before infusion, the patient has a lower risk of hypothermia.

Positioning the patient can also increase perfusion throughout the body; place the patient in a modified Trendelenburg’s position to facilitate venous return and to prevent excessive abdominal viscera shift and restriction of the diaphragm that occurs with the head-down position.

Patients and their families are often frightened and anxious. If the patient is awake, provide a running explanation of the procedures to reassure him or her. Hold the patient’s hand to offer reassurance when possible. Explain the treatment alternatives to the family and keep them updated as to the patient’s response to therapy. If blood component therapy is essential, answer the patient’s and family’s questions about the risks involved.

Evidence-Based Practice and Health Policy

Corradi, F., Brusasco, C., Vezzani, A., Palermo, S., Altomonte, F., Moscatelli, P., & Pelosi, P. (2011). Hemorrhagic shock in polytrauma patients: Early detection with renal Doppler resistive index measurements. Radiology, 260(1), 112–118.

Early detection of shock is critical to effective management and mortality risk reduction.
Investigators conducted a study among 52 hemodynamically stable patients who were admitted to the emergency room following multiple traumas in order to determine the effectiveness of the renal Doppler resistive index (RI) to predict hemorrhagic shock. To calculate the renal Doppler RI, three Doppler measurements were taken in three renal areas and then averaged to derive an index.
Twenty-nine of the patients who developed hemorrhagic shock were compared to the 23 patients who did not. The mean renal Doppler RI was higher among patients who developed hemorrhagic shock compared to those who did not (0.80 versus 0.63; p < 0.01).
A renal Doppler RI greater than 0.7 compared to equal or less than 0.7 was associated with a 57.8 increased odds of hemorrhagic shock (95% CI, 10.5 to 317; p < 0.001). Renal Doppler RI greater than 0.7 demonstrated 90% sensitivity to predict hemorrhagic shock and 87% specificity to rule out patients without hemorrhagic shock (p < 0.001).

Documentation guidelines

Adequacy of airway: Patency of airway, ease of respiration, chest expansion, respiratory rate, presence of stridor or wheezes
Cardiovascular assessment: Capillary blanch, quality of peripheral pulses, presence of gooseflesh, changes in vital signs (blood pressure and heart rate), skin color, cardiac rhythm, signs of uncorrected bleeding
Body temperature
Fluid balance: Intake and output, patency of IV lines, speed of fluid resuscitation

Discharge and home healthcare guidelines

Provide a complete explanation of all emergency treatments and answer the patient’s and family’s questions. Explain the possibility of complications to recovery, such as poor wound healing, infection, and anemia. Explain the risks of blood transfusion and answer any questions about exposure to blood-borne infections. As required, provide information about any follow-up laboratory procedures that might be needed after the patient is discharged.