Most common cause of hypotension in trauma patients?

AIIMS Delhi NO - 2017

Medical & Surgical Nursing

Easy

Appeared in: AIIMS Delhi NO - 2017

Explanation

Excessive blood loss (hemorrhage) is the leading cause of hypotension in trauma, resulting in a state known as hypovolemic shock.
The loss of circulating blood volume reduces the amount of blood returning to the heart (preload), which in turn decreases cardiac output and leads to a fall in arterial blood pressure.
Traumatic shock is primarily due to hypovolemia from either hemorrhage or plasma loss into tissues.
Hypotension is often a later sign of shock; initial compensatory signs include tachycardia and cool, clammy skin.

Option B: Fear and pain associated with trauma trigger a sympathetic nervous system response ('fight or flight'), which typically causes vasoconstriction and a temporary increase in heart rate and blood pressure.
Option C: IV fluid infusion is a primary treatment for hypotension caused by volume loss. It works by increasing the intravascular volume, which helps to raise blood pressure.
Option D: This option is incorrect because two of the choices (Fear and IV fluid infusion) do not cause hypotension in this context. Fear typically raises blood pressure initially, and IV fluids are a treatment to correct hypotension.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology of Shock in Trauma Patients as background academic context rather than a clinical decision trigger.
Nurses must prioritize assessing for and controlling hemorrhage in trauma patients. This includes looking for both obvious external bleeding and subtle signs of internal bleeding (e.g., abdominal distension, pelvic instability, bruising).
Hypotension is a late and ominous sign of decompensated shock. Early recognition of compensatory signs like tachycardia and tachypnea is critical for timely intervention and improved patient outcomes.
What if? If a trauma patient with a head injury develops hypotension and bradycardia (part of Cushing's triad), the cause is more likely to be increased intracranial pressure (ICP) causing brainstem compression, rather than hypovolemia. This requires different management, such as osmotic diuretics, instead of just fluid resuscitation.

How to Approach the Question

First, identify the core of the question: it asks for the most common cause of low blood pressure specifically in trauma patients.
Analyze the physiological effect of each option on blood pressure.
Evaluate 'Excessive blood loss'. Trauma frequently causes bleeding. A significant loss of blood volume directly reduces the pressure within the circulatory system. This is a direct and common link.
Evaluate 'Fear'. Fear activates the sympathetic nervous system (the 'fight or flight' response), which initially increases heart rate and blood pressure through vasoconstriction. This is the opposite of what the question asks.
Evaluate 'IV fluid infusion'. This is a medical intervention used to treat low blood pressure by adding volume to the circulation. It is a solution, not a cause.
Since 'Fear' and 'IV fluid infusion' are incorrect, the 'All of the above' option is also incorrect. This leaves 'Excessive blood loss' as the only logical and medically correct answer.

Concept Tested & Keywords

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E6 Physiology Guyton 4SAE Part 2A p. 26-28

E6 Medicine Davidson Principles Practice 24e p. 226-228