Shock

Shock is a life-threatening condition in which blood flow to your body organs is hindered for different reasons, resulting in deprivation of the organs with oxygen and nutrition that may cause severe damage to the organs, causing organ failure. If untreated, it can result in death. Anything that affects the circulatory system (blood flow system) can cause a shock, like heart defects, blood loss, allergic reaction, severe infection, trauma, severe burns, heatstroke, etc.

Your body organs depend on oxygen to work properly. In shock, the oxygen demand exceeds the supply, affecting the functions of the organs. Different conditions cause different types of shock. Treatment depends on the underlying cause and correction of the hydration status, blood flow, medications, etc.

Four major types of shock are described below;

1.       Hypovolemic shock: It’s the most common type. It results from insufficient blood volume that may result from severe blood loss (hemorrhage), diarrhea, or vomiting (especially in children), or may also be caused by excess urine production and excretion as in diabetic ketoacidosis and diabetes insipidus.

2.       Cardiogenic shock: The conditions that can adversely affect the heart and its functions, causing failure to pump enough blood, resulting in cardiogenic shock. Most commonly heart is damaged by myocardial infarction. Other causes are arrhythmias, cardiomyopathy, valvular heart disease, congestive heart failure.

3.       Obstructive shock: This shock results from obstructing the blood flow either in the great blood vessel or the pulmonary circulation. The blood is unable to flow due to obstruction and does not reach the whole body. Some conditions that can cause obstructive shock are; cardiac tamponade, tension pneumothorax, pulmonary embolism.

4.       Distributive shock: In this type, the blood vessels dilate, i.e., losing their tone and increasing in diameter resulting in the lack of pressure to pump the blood ahead, causing blood stasis and inability to distribute blood where needed. It can be caused by a severe allergic reaction (anaphylactic shock), severe infection (septic shock), or damage to the nervous system resulting in the loss of tone of the blood vessels (neurogenic shock).

There are several causes that may result in shock;

·         Severe Hemorrhage (blood loss)

·         Severe vomiting or diarrhea

·         Excessive urine loss

·         Myocardial infection

·         Cardiac tamponade

·         Heart failure

·         Trauma to the nervous system

·         A severe allergic reaction

·         A severe infection causing sepsis

·         Pneumothorax

·         Drug toxicities

The factors that can increase your chances of having a shock are;

·         Any disease affecting the heart

·         Any severe infection for which you may be hospitalized

·         Accident or trauma resulting in blood loss

·         If you are allergic to different things like food, medicines, sting bites, etc

·         Suffering from conditions like diabetes Mellitus that can cause diabetic ketoacidosis or diabetes insipidus

·         Suffering from endocrine disorders like hypothyroidism, hyperthyroidism, adrenal insufficiency

·         Suffer from accident or trauma affecting the nervous system

The hypovolemic shock was one of the most common types of shock. However, recent data focuses more on septic shock, which seems to be becoming commoner than hypovolemic shock. 1-2 % of trauma cases result in hypovolemic shock.

Shock accounts for one-third of the patients admitted to the ICU. Among them, around 20% of the cases are cardiogenic shock, 20% are hypovolemic shock, and 60% are septic shock.

Different types of shock result in a different set of symptoms. But the most common symptoms are;

·         Weak or absent pulse

·         Increased heart rate

·         Low blood pressure

·         Increased thirst, decreased urine

·         Low body temperature

·         Cold skin but maybe warm in cases of distributive shock

·         Confusion

·         Nausea

·         Chest pain

·         Breathing problems can be shortness of breath or rapid shallow breathing

·         Loss of consciousness

Diagnosis is made based on signs and symptoms, supported by various blood tests and imaging studies;

Patients may present to the physician's clinic or the emergency department with the mentioned signs and symptoms. The doctors will examine the patient for blood pressure, pulse rate, oxygen levels. The patient would be given first aid to maintain the airway, circulation, and breathing. Blood tests and other investigations would be ordered to make a cause-related diagnosis and treated accordingly.

• Blood tests: Blood tests can give a lot of information. Complete blood count (CBC), differentials leucocyte can show infections, low platelets, blood urea nitrogen (BUN), electrolytes, CRP, drug levels. 

• Imaging: Radiographs, ultrasounds, CT scans of different regions can show additional details like fractures of bone, growths or tumors, organs ruptures, etc., to find the underlying cause.

·         Systemic inflammatory response syndrome (SIRS)

·         Pulmonary embolism

·         Adrenal crisis

·         Burns

·         Anaphylaxis

·         Insect bite

·         Drug reaction

·         Aortic dissection

Patients suffering from shock usually come to the emergency department. They are given the first steps of medical care to stabilize them, like opening their airway and maintaining breathing and circulation. During the process, tests are ordered to find the underlying cause and start the focused treatment.

Treatment depends on the underlying cause of the shock.

·         IV fluids, blood products, medicines are given to maintain the blood pressure

·         Antibiotics are given for infections leading to sepsis

·         Heart treatment and catheterization is performed for the shock caused by the cardiac conditions

·         For the anaphylactic reaction, epinephrine is given.

Shock is a life-threatening condition but is vitally treatable. However, the cure rates depend on the types of shock. Hypovolemic, anaphylactic, and neurogenic shock have good outcomes if managed well on time. The mortality rate for septic shock is between 30% to 80%, while it is around 70-90% for cardiogenic shock.

Some cases of shock can be prevented by taking care of the following things;

·         You should know if you are allergic to anything. Keep a note and avoid those things.

·         Use protective gear while driving or playing sports.

·         Take proper care of your medicines if you have a heart condition. Take regular follow-ups.

·         Drink adequate amounts of fluid if you plan to go out in hot, humid temperatures.

·         To stay healthy and away from diseases, you should eat a well-balanced diet, perform regular exercise, maintain good sleep hygiene, avoid excessive alcohol and smoking.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 29, 2023.

References

Shock - StatPearls - NCBI Bookshelf (nih.gov)

https://www.ncbi.nlm.nih.gov/books/NBK531492/

Shock: First aid - Mayo Clinic

https://www.mayoclinic.org/first-aid/first-aid-shock/basics/art-20056620