Now many of our people out there have lost their loved ones in a way they call “abrupt death”, where someone was very fine just a few minutes/hours ago but died just like that. I know for sure you reading this article you may be a victim of such a situation. Now of you are ready to know about how it came about and how you will avoid it to happen on you and your other loved ones, read below: –
Circulatory shock, commonly known as shock, is a life-threatening medical condition of low blood perfusion to tissues resulting in cellular injury and inadequate tissue function
Shock is defined as a state of cellular and tissue hypoxia due to reduced oxygen delivery and/or increased oxygen consumption or inadequate oxygen utilization. This most commonly occurs when there is circulatory failure manifested as hypotension (i.e. reduced tissue perfusion).
OR: It may refer to circulatory system failure which happens when oxygenated blood is not provided in sufficient amounts for every body part.
The damage caused by shock depends on which body part is deprived of oxygen and for how long. For example, without oxygen, the brain will be reparably damaged in 4-6minutes, the abdominal organs in 45-90minutes and the skin & muscle cells in 3-6hours.
To understand shock, think about the circulatory system as having three components; the heart (working pump), the blood vessels (network of pipes), the blood (which is the adequate amount of fluids pumped through the pipes.) (Thygerson & Gulli, 2005).
Shock is initially reversible, but must be recognized and treated immediately to prevent progression to irreversible organ dysfunction. “Undifferentiated shock” refers to the situation where shock is recognized but the cause is unclear.
Shock is a life-threatening condition of circulatory failure. The effects of shock are initially reversible, but rapidly become irreversible, resulting in multi organ failure (MOF) and death. When a patient presents with undifferentiated shock, it is important that the clinician immediately initiate therapy while rapidly identifying the etiology so that definitive therapy can be administered to reverse shock and prevent MOF and death. Circulatory shock is not related to the emotional state of shock.
CLASSIFICATION AND ETIOLOGY
Four types of shock are recognized. That is; Distributive, Cardiogenic, Hypovolemic, and Obstructive. However, these are not exclusive, and many patients with circulatory failure have a combination of more than one form of shock (multifactorial shock). There are many etiologies within each class.
Distributive shock is due to impaired utilization of oxygen and thus production of energy by the cell. It is characterized by loss of blood vessel tone, enlargement of the vascular compartment and displacement of the vascular volume away from the heart and central circulation.
It occurs in 3 other forms of shock which include;
- Neurogenic shock
- Anaphylactic shock
- Septic shock.
Septic shock, a form of distributive shock and is the most common form of shock among patients admitted to the intensive care unit, followed by cardiogenic and hypovolemic shock; obstructive shock is rare. Septic shock results from bacteria multiplying in the blood and releasing toxins Caused by an overwhelming systemic infection resulting in vasodilatation hence leading to hypotension. Common causes of this are pneumonia, urinary tract infection, skin infections (cellulitis), and intra-abdominal infections (such as a ruptured appendix and meningitis.
SIGNS AND SYMPTOMS OF SEPTIC SHOCK
- Systemic leukoyte adhesion to endothelial tissue
- Reduced contractility of the heart
- Activation of the coagulation pathways, resulting in disseminated intravascular coagulation (DIC)
- Increased levels of neutrophils
Main manifestations are produced due to massive release of histamine which causes intense vasodilatation. The most generally accepted treatment for these patients is early recognition of symptoms, and early administration of broad spectrum and organism specific antibiotics.
Anaphylactic shock is a type of severe hypersensitivity or allergic reaction. Causes include allergy to insect stings, medicines, or foods (nuts, berries, and seafood). Anaphylactic shock is caused by a severe anaphylactic reaction to an allergen, antigen, drug or foreign protein causing the release of histamine which causes widespread vasodilatation, leading to hypotension and increased capillary permeability.
Neurogenic shock is caused by spinal cord injury, usually as a result of a traumatic accident or injury.
How do you know it’s shock. See below;
SIGNS AND SYMPTOMS
- Low blood pressure
- Rapid heart rate
- Weak pulses
- Signs of poor end-organ perfusion (i.e. low urine output, confusion, or loss of consciousness),
MANAGEMENT OF DISTRIBUTIVE SHOCK
All patients with distributive shock should be admitted to an intensive care unit (ICU). Vital signs and fluid intake and output should be measured and charted on an hourly basis. Daily weights should be obtained, and adequate intravascular access should be secured. A central venous access device should be considered if vasoactive drug support is required. Placement of pulmonary artery (PA) and arterial catheters should be considered. Most patients should have an indwelling urinary catheter.
Oxygen should be administered immediately by mask. In patients with altered mental status, respiratory distress, or severe hypotension, elective endotracheal intubation and mechanical ventilation should be considered; these avoid emergent intubation in the event of subsequent respiratory arrest. Mechanical ventilation can also aid in hemodynamic stabilization, by decreasing the demands posed by the respiratory muscles on the circulation (as much as 40% of the cardiac output during respiratory distress).
All patients should be treated prophylactically against thromboembolic disease, gastric stress ulceration, and pressure ulcers.
The typical signs of shock are The shock index (SI), defined as heart rate divided by systolic blood pressure, is an accurate diagnostic measure that is more useful than hypotension and tachycardia in isolation. Under normal conditions, a number between 0.5 and 0.8 is typically seen. Should that number increase so does suspicion of an underlying state of shock? Blood pressure alone may not be a reliable sign for shock, as there are times when a person is in circulatory shock but has a stable blood pressure.
Cardiogenic shock happens when the heart is damaged and unable to supply sufficient blood to the body. This can be the end result of a heart attack or congestive heart failure.
OR: Is defined by circulatory (pump) failure despite adequate intravascular volume.
Causes of cardiogenic shock
- Myocardio infarction
- Cardiac temponade. (Prevents adequate filling)
- Tension pneumothorax. (causes kinking of the venacava)
- Pulmonary embolus. (Obstructs the cardiac outflow)
Signs and symptoms of cardiogenic shock include:
- Distended jugular veins due to increased jugular venous pressure
- Weak or absent pulse
- The pulse pressure may be low, and patients are usually tachycardic
- Arrhythmia often tachycardia.
- Patients show signs of hypo perfusion, such as; altered mental status and decreased urine output.
- Reduced blood pressure
- Patients in shock usually appear cyanotic and have cool skin and extremities.
- Peripheral pulses are rapid and faint and may be irregular if arrhythmias are present
- Jugular venous distention
- Crackles in the lungs are usually (but not always) present.
- Peripheral edema also may be present.
- Heart sounds are usually distant, and third and fourth heart sounds may be present.
MANAGEMENT OF PATIENTS WITH CARDIOGENIC SHOCK.
- Critical/ Immediate management.
Untreated shock is usually fatal. Even with treatment, mortality from cardiogenic shock after MI (60 to 65%) and septic shock (30 to 40%) is high. Prognosis depends on the cause, preexisting or complicating illness, time between onset and diagnosis, and promptness and adequacy of therapy.
- Call for help
- Take quick history following the patient’s ill condition.
- Keep the patient warm.
- Connect the patient on monitors
- Control hemorrhage. In case it’s present. This is common in hemorrhagic shock.
- Check for ABC’s.
Hypovolemic shock is caused by severe blood and fluid loss, such as from traumatic bodily injury, which makes the heart unable to pump enough blood to the body, or severe anemia where there is not enough blood to carry oxygen through the body.
Hypovolemia leads to:
- A rapid, weak, thready pulse due to decreased blood flow combined with tachycardia
- Cool, clammy skin due to vasoconstriction.
- Rapid and shallow breathing due to sympathetic nervous system stimulation and acidosis
- Hypothermia due to decreased perfusion
- Thirst and dry mouth, due to fluid depletion
- Cold skin, especially extremities, due to insufficient perfusion of the skin.
MANAGEMENT OF HYPOVOLEMIC SHOCK
- Ensure that the patient has an adequate airway.
- Patient is ventilating appropriately. Some patients may require intubation.
- Replace volume losses. With Blood products, colloids, crystalloids.
- Address the etiology. For instance hemorrhage by arresting bleeding in all affected sites.
Obstructive shock is due to obstruction of blood flow outside of the heart. Several conditions can result in this form of shock.
- Cardiac tamponade in which fluid in the pericardium prevents inflow of blood into the heart (venous return).
- Constructive pericarditis, in which the pericardium shrinks and hardens, is similar in presentation.
- Tension pneumothorax through increased intrathoracic pressure, blood flow to the heart is prevented (venous return).
- Pulmonary embolism is the result of a thromboembolic incident in the blood vessels of the lungs and hinders the return of blood to the heart.
- Aortic stenosis hinders circulation by obstructing the ventricular outflow tract