SHOCK
Shock is a medical condition that arises when the tissues in the body do not receive sufficient blood flow as a result of problems with the circulatory system
- Lack of blood flow means a lack of oxygen and nutrients to allow the cells in the body function properly.
- This leads to cellular death, progressing to organ failure, and finally if not treated, complete body failure and even death.
- Medical shock is a medical emergency that requires immediate treatment as symptoms can worsen rapidly.
- Treating shock immediately can be life-saving.
- Medical shock is totally different from an emotional or psychological shock that can occur from a traumatic or frightening emotional event.
- There are four stages of shock: initial stage, the compensatory stage, progressive stage, and the refractory stage.
- At the initial stage, cells begin to change as a result of perfusion and oxygenation. Perfusion refers to the process by which the veins deliver blood to the capillary beds within the body tissues. This further results in the cells using anaerobic (without oxygen) metabolism to function instead of the aerobic (with oxygen) metabolism. Lactic acid and pyruvic acid are formed as a by-product of anaerobic metabolism. This initial stage of shock is reversible but does not show any obvious symptom that would signal that the body is entering a stage of shock.
- During the compensatory stage, the body employs physiological mechanisms including a neural, hormonal, and biochemical mechanism to reverse the result of the initial stage. Hyperventilation is one of these mechanisms. During hyperventilation, there is an increased rate of breathing which improves oxygen flow to the cells. This helps to neutralize the acidic condition and to raise the pH of the blood. Another mechanism used by the body is referred to as the catecholamine response. Catecholamines are hormones that are released by the adrenal gland and are triggered by low blood pressure caused by the reduced volume of blood flow. These hormones aim to increase the heart rate in order to increase blood pressure. The renin-angiotensin response is another mechanism used by the body. During this response, vasopressin is released into the bloodstream to help conserve fluid via the kidneys and triggers vasoconstriction of the kidneys, GI tract and other organs to divert blood to the heart, lungs, and brain.
- At the progressive stage, damage done to the body is more severe and may be irreversible, if the cause of the crisis is yet to be successfully treated. As anaerobic mechanism continues, the body’s metabolic acidosis increases, cellular function deteriorates, and the compensatory mechanism begins to fail and is not able to maintain the balance needed to protect the organs.
- During the refractory stage, the body enters the last stage of shock, the organs fail and death may follow.
CAUSES
The underlying cause has been divided into four main parts:
The cardiogenic shock which may be due to damage to the heart from myocardial infarction, dysrhythmias, congestive heart failure, cardiomyopathy, or valvular heart disease.
Hypovolemic shock is the most common type and results from severe external or internal bleeding, dehydration, kidney failure, inflammation of the pancreas, extensive burns, or diabetes insipidus.
The distributive shock which may include:
- Septic shock caused by bacteria such as Escherichia coli, Proteus species, Klebsiella pneumonia.
- Anaphylactic shock caused by reactions to allergens, antigen, drug or foreign protein that causes the release of histamine.
- The neurogenic shock that occurs from high spinal cord injuries/ trauma.
The obstructive shock that may result from conditions such as cardiac tamponade, tension pneumothorax, aortic stenosis, pulmonary embolism.
SYMPTOMS
- Pale skin
- Rapid pulse
- Rapid breathing
- Weakness or fatigue
- Dizziness
- Nausea or vomiting
- Enlarged pupils
- Cool, clammy skin
- Thirst and dry mouth
- Feeling anxious, agitated, or confused
- Profuse sweating
DIAGNOSIS AND TREATMENT
Diagnosis is generally based on a combination of symptoms, physical examination and laboratory tests (X-ray, blood tests, EKGs) to determine the underlying cause of the shock and the severity of your illness.
TREATMENT
Treatment is based on the underlying cause.
The first course of action is to give fluid resuscitation. This means that a large amount of water is given with an IV whether in an ambulance or emergency room to raise the blood pressure.
Medications such as epinephrine, dopamine may be administered along with the fluid to try to raise blood pressure to ensure blood flows to the vital organs.
Treatment may also include securing the airway if necessary to decrease the work of breathing and to guard against respiratory arrest.
Septic shock is treated with quick administration of antibiotics depending on the source and type of the infection causing the shock.
In minor cases, hypovolemic shock is treated with fluids but may require multiple blood transfusion in severe cases.