Shock is a condition in which there is a progressive loss of blood volume responsible for maintaining effective systemic blood circulation throughout the body’s interlacing and interdependent organ systems. Insufficient organ and tissue perfusion occurs when not enough blood reaches the capillary circulation which ultimately leads to cellular metabolic disarray and if not promptly managed almost always results in death.
In any emergency situation, the onset of shock should always be anticipated by comprehensively assessing and evaluating all injured victims as soon as possible. The underlying cause of shock (hypovolemic, cardiogenic, septic, neurogenic or anaphylactic) must be narrowed down as promptly as possible in order to give the most appropriate definitive treatment for the specific cause of shock. Of the above mentioned classification of shock, hypovolemic shock is the most common one.
Common causes of Hypovolemia
The most common causes of hypovolemia include the following:
- Excessive loss of blood (external or internal bleeding).
- Excessive loss of plasma component of the blood (full-thickness burns).
- Excessive loss of the body’s electrolytes (sodium and potassium) from excessive sweating, vomiting or diarrhea.
- Vasodilatory nerve dysfunction due to trauma to the vasomotor center in the brain which causes disorganized inhibition and stimulation of the blood vessels.
Emergency care for victims with hypovolemia is normally started by ensuring a patent air passageway and maintaining breathing if the victim is still not under the care of emergency medical services. Once emergency help arrives or the individual is rushed to the emergency department, additional ventilatory assistance is initiated and a quick but comprehensive physical assessment is done to determine the cause of shock.
Usually, the initial goal of the health team tending the individual for hypovolemia is restoring the adequate blood volume by rapidly infusing intravenous fluids, blood products or blood replacements based on the assessment findings, taking special precautions if the individual has preexisting cardiac and kidney dysfunctions. Blood component therapy or blood transfusion can significantly assist in optimizing cardiac preload, correcting hypotension and increasing tissue perfusion.
Until such time the prerequisite tests for blood transfusion is carried out (blood typing and cross-matching) and completed, IV fluids are infused at a rapid rate until systolic blood pressure increases above acceptable levels or until there is improvement in the individual’s current clinical condition. Infusion of IV fluids specifically Lactated Ringer’s solution is an effective initial treatment for hypovolemia since it approximates the remaining blood’s plasma electrolyte compositions and osmolality which consequently allows for the required blood tests to be completed. Moreover, the solution serves as an adjunct to blood transfusion therapy.
Blood transfusion or blood component therapy is almost always included as a definitive treatment for hypovolemic shock especially if blood loss has been severe or if the individual is currently hemorrhaging. Measures to control hemorrhage are instigated primarily because hemorrhage compounds the state of shock. When blood transfusion is initiated, the legs should be slightly elevated to promote venous return to the heart and to improve perfusion cerebral tissues. However, this is highly contraindicated for individuals with diagnosed and/or suspected head injuries since it can aggravate and further increase intracranial pressure.