Workers’ Compensation Claims of Physiological Shock


Physiological shock[1], also known as circulatory shock or simply shock, is a failure of the circulatory system to provide adequate amounts of blood to the vital organs and peripheral tissues for introduction of oxygen and nutrients and removal of metabolic wastes.  Shock is typically caused by significant blood loss and a concomitant reduction in cardiac and pulmonary performance and efficiency.   This article briefly outlines the symptoms of physiological shock and the medicolegal and administrative considerations for determining whether an injured worker may suffer from compensable physiological shock.

  Symptoms of Shock

The following are typical symptoms of physiological shock.

Increased Heart Rate

A decrease in the volume of blood will activate the baroreceptors[2] in the heart and carotid vessels, which will cause an increase in the heart rate to provide sufficient blood supply to the vital organs.  A rapid, weak pulse suggests an increase in contraction rate of the heart and a corresponding weak pulse indicates reduced blood in the vessels.

Pale, Cold, Clammy Skin

The skin aids in regulation of body temperature.  A decrease in blood volume will result in vasoconstriction of the peripheral vessels, restricting heat exchange with the external environment, and diverting blood flow from the skin and least priority tissues to the vital organs.   As a result, the skin becomes pale, cool, and clammy and the internal body temperature increases.

Rapid, Shallow Breathing

The pulmonary and circulatory systems are interconnected.   Blood pumped from the heart through the arteries provide nutrients and oxygen to the organs and tissues.  Blood then returns though the veins to the lungs, where the blood is reoxygenated, and then to the heart.  Reduced blood to the lungs will shorten the pace and depth of breathing.

Claims for Physiological Shock

A worker may allege a traumatic industrial accident or exposure to injurious occupational conditions that impedes the body’s circulatory system’s ability to provide adequate circulation to the vital organs, such as the brain, heart and lungs.  A claim for physiological shock may be a direct result of the alleged industrial injury or occupational disease, or it may be a consequential condition of the workplace incident or exposures.[3]

Medical evidence is necessary to assess whether the alleged physiological or circulatory shock is medically and proximately caused by a specific traumatic workplace event or incident (industrial injury) or occupational exposures/repetitive conditions (occupational disease).  Objective medical evidence should reveal whether the worker suffers from physiological shock and, if so, the specific type of circulatory shock.  Such evidence should assist to determine compensability – whether the worker’s purported shock was proximately caused by an industrial injury or occupational disease.

Questions should be posed to the treating physicians and/or independent medical examiners to aid in determining whether symptoms, such as rapid heart rate or pale, cool and clammy skin, are signs of physiological shock.  If the symptoms suggest circulatory compromise, the physicians should be asked to identify the specific type of shock in addition to its cause(s).

Classification of Shock

Physiological shock is classified as hypovolemic, distributive, or cardiac shock.  While each type of is an independent form of physiological shock, they are not mutually exclusive and may overlap with one another.

Hypovolemic Shock

Hypovolemia (also hypovolaemia) is a state of decreased blood volume, typically in excess of 20 percent of the body’s blood supply.  The condition is caused by hemorrhage, rupture of internal organ(s), and/or severe dehydration.  As a result, the heart is unable to pump a sufficient supply of blood to the vital organs, which will cause overwhelming catastrophic failure.  It is a life-threatening condition that demands emergency medical attention to survive.

Distributive Shock

Distributive shock low blood pressure (hypotension) and generalized oxygen deprivation of tissue (hypoxia) caused by vasodilation.  The most common causes ate septic shock from overwhelming infection and anaphalyctic shock, a severe allergic reaction.

Cardiogenic Shock

Cardiogenic shock is a condition in which the heart is unable to pump enough blood to meet the body’s needs.  Causes cardiogenic shock include acute mycardial infarction, arrhythmia such as ventricular fibrillation, and cardiac valve insufficiency.


Physiological shock, a failure of the body’s circulatory system to provide sufficient blood to the vital organs and tissues, may be a direct or an indirect consequence of a traumatic workplace incident (industrial injury) or exposure to injurious conditions of employment (occupational disease).  A basic understanding of the symptoms and types of circulatory shock will assist in posing proper questions for treating physicians and/or independent medical examiners to address issues of etiology and causation.  Such assessments should aid in determining whether the worker suffers from physiological shock caused by or otherwise related to an industrial injury or occupational disease.

If you have general or specific questions how to address a claim for physiological or circulatory shock, please contact one of our attorneys to discuss claims management, administrative action plans, advice and/or representation on behalf of an employer and/or insurer.

[1] Physiological shock should not be confused with the emotional state of shock, which is an acute stress reaction in response to a terrifying or traumatic event.
[2] Baroreceptors are sensory nerve endings in the walls of the heart, and vascular walls of the vena cava, carotid sinus and aortic arch, sensitive to stretching or contracting due to a change in pressure.
[3] See, Workers’ Compensation: Basic Elements of a Compensable Claim in Washington and Oregon, by Michael H. Weier, 8/01/2013, and Causation and The Doctrine of Compensable Consequences, by Michael H. Weier, 9/17/2013.