SHOCK

The term “shock” may refer to a psychologic or a physiologic type of shock. Physiologic shock

is insufficient blood supply to organs and tissues. Psychologic shock is caused by a traumatic

event and is also known as acute stress disorder. This type of shock causes a strong emotional

response and may cause physical responses as well. Shock discussed below is according to Kahn

(2019)

Types of physiologic shock

There are four major types of shock based on the cause of the shock

Hypovolemic Shock

Hypovolemic shock, the most common type, is caused by insufficient circulating volume,

typically from hemorrhage although severe vomiting and diarrhea are also potential causes.

Hypovolemic shock is graded on a four-point scale depending on the severity of symptoms and

level of blood loss. Typical symptoms include a rapid, weak pulse due to decreased blood flow

combined with tachycardia, cool, clammy skin, and rapid and shallow breathing.

Grading scale for hypovolemic shock

Four-point scale for grading hypovolemic shock according to Hooper and Armstrong (2022) in a

70kg adult male

Class 1: Volume loss up to 15% of total blood volume, approximately 750 mL. Heart rate is

minimally elevated or normal. Typically, there is no change in blood pressure, pulse pressure, or

respiratory rate.
Class 2: Volume loss from 15% to 30% of total blood volume, from 750 mL to 1500 mL. Heart

rate and respiratory rate become elevated (100 BPM to 120 BPM, 20 RR to 24 RR). Pulse

pressure begins to narrow, but systolic blood pressure may be unchanged to slightly decreased.

Class 3: Volume loss from 30% to 40% of total blood volume, from 1500 mL to 2000 mL. A

significant drop in blood pressure and changes in mental status occurs. Heart rate and respiratory

rate are significantly elevated (more than 120 BPM). Urine output declines. Capillary refill is

delayed.

Class 4: Volume loss over 40% of total blood volume. Hypotension with narrow pulse pressure

(less than 25 mmHg). Tachycardia becomes more pronounced (more than 120 BPM), and mental

status becomes increasingly altered. Urine output is minimal or absent. Capillary refill is delayed

Cardiogenic Shock

Cardiogenic shock is caused by a failure of the heart to pump correctly, either due to damage to

the heart muscle due to myocardial infarction (also called heart attack is the blockage of blood

flow to the heart), cardiac valve problems, congestive heart failure ( this is a disease that occurs

when the heart is unable to pump blood through out the body efficiently), or dysrhythmia.

Obstructive Shock

Obstructive shock is caused by an obstruction of blood flow outside of the heart. This typically

occurs due to interruption to blood flow that results in a reduction in venous return. It may also

be caused by blockage of the aorta. Conditions that can cause a buildup of air or fluid in the chest

cavity can also lead to obstructive shock. These include:

Pneumothorax (collapsed lung)

Cardiac tamponade (blood or fluids fill the space between the sac that surrounds the heart and the

heart muscle)

Distributive Shock

Distributive shock is caused by an abnormal supply of blood to tissues and organs. This includes

septic, anaphylactic, and neurogenic causes. Drug toxicities and brain injuries can also lead to

distributive shock.

Septic shock

Septic shock is the most common cause of distributive shock and is caused by an overwhelming

systemic infection that cannot be cleared by the immune system, resulting in vasodilation and

hypotension.

Anaphylactic shock

Anaphylactic shock is caused by a severe reaction to an allergen, leading to the release of

histamine that causes widespread vasodilation and hypotension. Anaphylactic shock is a

complication of a severe allergic reaction known as anaphylaxis. Allergic reactions occur when

the body mistakenly treats a harmless substance as harmful. This triggers a dangerous immune

response. Anaphylaxis is usually caused by allergic reactions to food, insect venom, medications,

or latex.

Neurogenic shock
Neurogenic shock arises due to damage to the central nervous system, which impairs cardiac

function by reducing heart rate and vasodilation, resulting in severe hypotension.

Clinical Manifestation

The signs and symptoms of shock include

 Rapid, weak, or absent pulse

 Irregular heartbeat

 Rapid, shallow breathing

 Lightheadedness

 Cool, clammy skin

 Dilated pupils

 Lackluster eyes

 Chest pain

 Nausea

 Confusion

 Anxiety

 Decrease in urine

 Thirst and dry mouth

 Low blood sugar

 Loss of consciousness
First aid treatment

If you suspect someone has gone into shock, call for help. Then follow these steps:

If they are re unconscious, check to see if they are still breathing and have a heartbeat.

If there is no breathing or a heartbeat, begin CPR.

Lay them down on their back.

Elevate their feet at least 12 inches above the ground (Trendelenburg’sposition). This position,

known as the shock position, helps direct blood to their vital organs where it’s most needed.

Cover them with a blanket or extra clothing to help keep them warm.

Check their breathing and heart rate regularly for changes.

If you suspect the person has injured their head, neck, or back, avoid moving them.

Apply first aid to any visible wounds. If you suspect the person is experiencing an allergic

reaction, ask them if they have an epinephrine auto-injector (EpiPen). People with severe

allergies often carry this device. It contains an easy-to-inject needle with a dose of hormone

called epinephrine. You can use it to treat anaphylaxis.

If they begin to vomit, turn their head sideways. This helps prevent choking. If you suspect

they’ve injured their neck or back, avoid turning their head. Instead, stabilize their neck and roll

their entire body to the side to clear the vomit out.

Management

The management plan for shock will depend on the cause of your condition. Different types of

shock are treated differently. For example, your doctor may use:

epinephrine and other drugs to treat anaphylactic shock

blood transfusion to replace lost blood and treat hypovolemic shock

medications, heart surgery, or other interventions to treat cardiogenic shock

Factors that affects from recovery and long-term outlook of shock include

the cause of shock

the length of time you were in shock

the area and extent of organ damage that you sustained

the treatment and care that you received

your age and medical history

Prevention

Some forms and cases of shock are preventable. Measures to prevent shock include

Those with severe allergies should avoid triggers, carry an epinephrine auto-injector, and use it

at the first sign of an anaphylactic reaction.

To lower the risk of blood loss from injuries, wear protective gear when taking part in contact

sports, riding your bike, and using dangerous equipment. Wear a seatbelt when traveling in motor

vehicles.

To lower your chances of heart damage, eat a well-balanced diet, exercise regularly, and avoid

smoking and secondhand smoke.

Stay hydrated by drinking plenty of fluids. This is especially important when you’re spending

time in very hot or humid environments.

Complications
The complications of shock include

Unconsciousness

Respiratory failure

Cardiac arrest

Liver failure

Kidney failure