Question

Discuss different types of shock including pathophysiology, symptoms, and treatment?

Answer 1

Definition: Shock is a life threatening condition that occurs when the body is not getting enough blood flow which leads to reduced amount of oxygen and nutrients to the organs to function properly. Due to shock many organ are damaged.

Types of shock:

• Cardiogenic shock (due to heart problems)
• Hypovolemic shock (caused by too little blood volume)
• Anaphylactic shock (caused by allergic reaction)
• Septic shock (due to infections)
• Neurogenic shock (caused by damage to the nervous system)

Cardiogenic shock:

It is when the heart is damaged and thus cannot or unable to supply enough blood to the organs of the body.

Causes:

• A large section of heart muscle that no longer moves well or does not move at all
• Breaking open (rupture) of the heart muscle due to damage from the heart attack
• Dangerous heart rhythms, such as ventricular tachycardia, ventricular fibrillation, or supraventricular tachycardia
• Pressure on the heart due to a build up of fluid around it (pericardial tamponade)
• Tear or rupture of the muscles or tendons that support the heart valves, especially the mitral valve
• Tear or rupture of the wall (septum) between the left and right ventricles (lower heart chambers)
• Very slow heart rhythm (bradycardia) or problem with the electrical system of the heart (heart block)

Pathophysiology:

When there is reduced oxygen supply, there will be increase in the heart rate. This leads to myocardial infarction which causes critical decrease in LV systolic and diastolic function, reduced cardiac output. This reduced the arterial blood pressure and there is systemic hypoxia. This leads to LV failure and death.

Symptoms:

• Chest pain or pressure
• Coma
• Decreased urination
• Fast breathing
• Fast pulse
• Heavy sweating, moist skin
• Light headedness
• Loss of alertness and ability to concentrate
• Restlessness, agitation, confusion
• Shortness of breath
• Skin that feels cool to the touch
• Pale skin color or blotchy skin
• Weak (thready) pulse

Diagnostic tests:

• Cardiac catheterization
• Chest x-ray
• Coronary angiography
• Echocardiogram
• Electrocardiogram
• Nuclear scan of the heart
• Arterial blood gas
• Blood chemistry (chem-7, chem-20, electrolytes)
• Cardiac enzymes (troponin, CKMB)
• Complete blood count (CBC)
• Thyroid stimulating hormone (TSH)

Treatment:

• Dobutamine
• Dopamine
• Epinephrine
• Levosimendan
• Milrinone
• Norepinephrine
• Electrical "shock" therapy (defibrillation or cardioversion)
• Implanting a temporary pacemaker
• Medicines given through a vein (IV)
• Pain medicine
• Oxygen
• Fluids, blood, and blood products through a vein (IV)
• Cardiac catheterization with coronary angioplasty and stenting
• Heart monitoring to guide treatment
• Heart surgery (coronary artery bypass surgery, heart valve replacement, left ventricular assist device)
• Intra-aortic balloon counterpulsation (IABP) to help the heart work better
• Pacemaker
• Ventricular assist device or other mechanical support

Hypovolemic shock:

It is an emergency condition in which severe blood or fluid loss makes the heart unable to pump enough blood to the body. This causes many organs to stop working.

Pathophysiology:

Due to hypovolemia that is severe blood or fluid loss from the body causes reduced venous return. This causes reduced preload which again causes reduced cardiac output. Due to reduced cardiac output the patient will have low blood pressure; this causes perfusion failure and tissue hypoxia which causes organ dysfunction and multi-organ failure.

Causes:

• Bleeding from cuts
• Bleeding from other injuries
• Internal bleeding, such as in the gastrointestinal tract
• Burns
• Diarrhea
• Excessive perspiration
• Vomiting

Symptoms

• Anxiety or agitation
• Cool, clammy skin
• Confusion
• Decreased or no urine output
• General weakness
• Pale skin color (pallor)
• Rapid breathing
• Sweating, moist skin
• Unconsciousness
• Low blood pressure
• Low body temperature
• Rapid pulse, often weak and thready

Diagnostic tests:

• Blood chemistry, including kidney function tests and those tests looking for evidence of heart muscle damage
• Complete blood count (CBC)
• CT scan, ultrasound, or x-ray of suspected areas
• Echocardiogram: sound wave test of heart structure and function
• Endoscopy: tube placed in the mouth to the stomach (upper endoscopy) or colonoscopy (tube placed through the rectum to the large bowel)
• Right heart (Swan-Ganz) catheterization
• Urinary catheterization (tube placed into the bladder to measure urine output)

Treatment

• Keep the person comfortable and warm (to avoid hypothermia).
• Have the person lie flat with the feet lifted about 12 inches (30 centimeters) to increase circulation. However, if the person has a head, neck, back, or leg injury, do not change the person's position unless they are in immediate danger.
• Do not give fluids by mouth.
• If person is having an allergic reaction, treat the allergic reaction, if you know how.
• If the person must be carried, try to keep them flat, with the head down and feet lifted.
• Stabilize the head and neck before moving a person with a suspected spinal injury.
• An intravenous (IV) line will be put into the person's arm to allow blood or blood products to be given.
• Medicines such as dopamine, dobutamine, epinephrine, and norepinephrine may be needed to increase blood pressure and the amount of blood pumped out of the heart (cardiac output).

Anaphylactic shock:

It is a life-threatening type of allergic reaction.

Causes:

• Drug allergies
• Food allergies
• Insect bites/stings
• Pollen and other inhaled allergens rarely cause anaphylaxis.
• Some people have an anaphylactic reaction with no known cause.

Pathophysiology:

When the patient is exposed to any allergic agents, the antigen enters into the blood stream. The antigen attacks B cell. The IgE antibody binds to surface of mast cells via the receptors. Calcium influx develops into the mast cells which releases chemical mediators, this effects the lungs, heart, skin and causes anaphylactic reactions.

Symptoms:

• Abdominal pain
• Feeling anxious
• Chest discomfort or tightness
• Diarrhea
• Difficulty breathing, coughing, wheezing, or high-pitched breathing sounds
• Difficulty swallowing
• Dizziness or lightheadedness
• Hives, itchiness, redness of the skin
• Nasal congestion
• Nausea or vomiting
• Palpitations
• Slurred speech
• Swelling of the face, eyes, or tongue
• Unconsciousness

Diagnostic test:

• Examination
• Tests for the allergen

Treatment:

1. Call 911.
2. Calm and reassure the person.
3. If the allergic reaction is from a bee sting, scrape the stinger off the skin with something firm (such as a fingernail or plastic credit card). Do not use tweezers. Squeezing the stinger will release more venom.
4. If the person has emergency allergy medicine on hand, help the person take or inject it. Do not give medicine through the mouth if the person is having difficulty breathing.
5. Take steps to prevent shock. Have the person lie flat, raise the person's feet about 12 inches (30 centimeters), and cover the person with a coat or blanket. Do not place the person in this position if a head, neck, back, or leg injury is suspected, or if it causes discomfort.

DO NOT:

• Do not assume that any allergy shots the person has already received will provide complete protection.
• Do not place a pillow under the person's head if they are having trouble breathing. This can block the airways.
• Do not give the person anything by mouth if they are having trouble breathing.
• Paramedics or other providers may place a tube through the nose or mouth into the airways.
• Or emergency surgery will be done to place a tube directly into the trachea.

Septic shock:

It is a serious condition that occurs when a body-wide infection leads to dangerously low blood pressure.

Pathophysiology:

The bacterial infection causes excessive host response. These host factors leads to cellular damage thus leading to organ damage and death.

Causes:

• Very old and the very young people
• People with weakened immune systems.
• Bacterial infection
• Fungi and (rarely) viruses may also cause the condition.

Risk factors:

• Diabetes
• Diseases of the genitourinary system, biliary system, or intestinal system
• Diseases that weaken the immune system, such as AIDS
• Indwelling catheters (those that remain in place for extended periods, especially intravenous lines and urinary catheters, and plastic and metal stents used for drainage)
• Leukemia
• Long-term use of antibiotics
• Lymphoma
• Recent infection
• Recent surgery or medical procedure
• Recent use of steroid medicines
• Solid organ or bone marrow transplantation

Symptoms:

• Cool, pale arms and legs
• High or very low temperature, chills
• Light headedness
• Little or no urine
• Low blood pressure, especially when standing
• Palpitations
• Rapid heart rate
• Restlessness, agitation, lethargy, or confusion
• Shortness of breath
• Skin rash or discoloration
• Decreased mental status

Diagnostic tests:

• Complete blood count (CBC) and blood chemistry
• Low blood oxygen level
• Disturbances in the body's acid-base balance
• A chest x-ray to look for pneumonia or fluid in the lungs (pulmonary edema)
• A urine sample to look for infection

Treatment:

• Breathing machine (mechanical ventilation)
• Dialysis
• Drugs to treat low blood pressure, infection, or blood clotting
• Fluids given directly into a vein (intravenously)
• Oxygen
• Sedatives
• Surgery to drain infected areas, if needed
• Antibiotics

Neurogenic shock:

It is a life-threatening condition caused by irregular blood circulation in the body. Trauma or injury to the spine can cause this disruption. Neurogenic shock is extremely dangerous because it can cause your blood pressure to drop drastically and suddenly, and can leave irreversible damage to your body tissues. If left untreated, neurogenic shock can be fatal.

Pathophysiology:

There is disruption of sympathetic nervous system which causes loss of sympathetic tone, venous and arterial vasodilatation. This causes decreased venous return, decreased stroke volume, decreased cardiac output, decreased cellular oxygen supply and thus causes impaired tissue perfusion and impaired cellular metabolism.

Symptoms:

• Dizziness
• Nausea
• Vomiting
• Blank stares
• Fainting
• Increased sweating
• Anxiety
• Pale skin
• Difficulty breathing
• Chest pain
• Weakness from irregular blood circulation
• Bradycardia, or a slower heart rhythm
• Faint pulse
• Cyanosis, or discolored lips and fingers
• Hypothermia, or decreased body temperature

Causes:

• Car accidents that cause central nervous system damage or spinal cord injury
• Sport injuries causing trauma to the spine
• Gunshot wounds to the spine
• Medications that affect the autonomic nervous system, which regulates breathing and other automatic bodily functions
• Improper administration of anesthesia to the spinal cord

Diagnostic test:

• CT scan
• MRI

Treatment:

• Norepinephrine
• Epinephrine
• Dopamine
• Vasopressin