Hemorrhage circulatory, shock and heart failure
Hemorrhage, Circulatory Shock and Heart Failure
Hemorrhage • Circulatory Shock • Syncope or Fainting • Heart Failure
Hemorrhage
Definition
Hemorrhage is defined as excess loss of blood due to rupture of blood vessels.
Types and Causes of Hemorrhage
Hemorrhage occurs because of various reasons. Based on cause, hemorrhage is classified into five categories.
1. Accidental Hemorrhage
Accidental hemorrhage occurs during road accidents and industrial accidents.
2. Capillary Hemorrhage
Capillary hemorrhage is the bleeding due to rupture of capillaries.
It is very common in brain and heart during cardiovascular diseases.
3. Internal Hemorrhage
Internal hemorrhage is the bleeding in viscera.
It is caused by rupture of blood vessels in the viscera.
4. Postpartum Hemorrhage
Postpartum hemorrhage is the excess bleeding that occurs immediately after labor.
5. Hemorrhage Due to Premature Detachment of Placenta
In some cases, the placenta is detached from uterus of mother before the due date of delivery causing severe hemorrhage.
Effects of Hemorrhage
Many effects are observed during and after hemorrhage. Effects are different in acute hemorrhage and chronic hemorrhage.
Acute Hemorrhage
Acute hemorrhage is the sudden loss of large quantity of blood.
It occurs in conditions like accidents.
Decreased blood volume in acute hemorrhage causes hypovolemic shock.
Chronic Hemorrhage
Chronic hemorrhage is the loss of blood either by internal or by external bleeding over a long period of time.
Internal bleeding occurs in conditions like ulcer.
External bleeding occurs in conditions like hemorrhoids and excessive vaginal bleeding (menorrhagia).
Chronic hemorrhage produces different effects such as anemia.
Compensatory Effects
After hemorrhage, a series of compensatory reactions develop in the body to cope up with the blood loss.
Some of the compensatory reactions develop immediately after hemorrhage and others at a later period.
Circulatory Shock
Definition
Shock is a general term that refers to depression or suppression of body functions produced by any disorder.
Circulatory shock is the shock developed by inadequate blood flow throughout the body.
Circulatory shock is a life-threatening condition and if the affected person is not treated immediately, it may result in death.
Manifestations of Circulatory Shock
1. Cardiovascular System
Common feature of circulatory shock is fall in arterial blood pressure which results in decreased blood flow to all organs.
2. Respiratory System
Breathing becomes rapid and shallow resulting in hypoventilation.
Some persons may develop respiratory distress syndrome.
3. Kidneys
Initially, urinary output is reduced.
Later tubular necrosis develops resulting in acute renal failure.
4. Skin
Because of stagnant hypoxia skin becomes pale and cold.
Cyanosis develops in many parts of the body, particularly in earlobes and fingertips.
There is excessive sweating.
5. Vital Organs
Vital organs such as liver and endocrine glands fail to function due to necrosis.
6. Brain
Lack of blood flow to brain tissues produces ischemia resulting in fainting and irreversible damage of brain tissues.
Finally, the brain damage and cardiac arrest cause death of the victim.
Types of Circulatory Shock
Circulatory shock is classified into four types:
I. Shock Due to Decreased Blood Volume: Hypovolemic Shock
Shock due to decreased blood volume is called hypovolemic shock.
It occurs when there is a loss of at least 10 to 15% of blood.
Important manifestations of hypovolemic shock are decrease in cardiac output, decrease in blood pressure, increase in respiratory rate, and restlessness or lethargy.
Common Types of Hypovolemic Shock
1. Hemorrhagic Shock
Hemorrhagic shock is the shock that occurs due to hemorrhage.
Acute hemorrhage as in the case of accident causes shock.
2. Traumatic Shock
Traumatic shock is developed due to trauma (serious injury or wound caused by some external force).
3. Surgical Shock
It is caused by internal hemorrhage, external hemorrhage or dehydration that occur during or after surgical procedures.
4. Burn Shock
Burn shock is produced by the effects of burn.
5. Dehydration Shock
Shock which is developed during severe dehydration is called dehydration shock.
II. Shock Due to Increased Vascular Capacity: Vasogenic Shock
Shock occurs because of inadequate blood supply to the tissues due to increased vascular capacity.
Capacity of the vascular system increases by extensive dilation of blood vessels.
It is also known as vasogenic shock.
Common Types of Vasogenic Shock
1. Neurogenic Shock
Neurogenic shock is the type of shock characterized by sudden depression of nervous system due to extensive vasodilatation caused by loss of vasomotor tone.
Common feature of neurogenic shock is syncope.
2. Anaphylactic Shock
Anaphylaxis means exaggerated allergic reaction to a foreign protein or antigen or any other substance to which the person has been previously sensitized.
Shock that develops during anaphylactic reactions is called anaphylactic shock.
3. Septic Shock
Sepsis is a condition characterized by the presence of pathogenic organisms or their toxins in blood or tissues.
Shock developed during sepsis is known as septic shock or blood poisoning.
III. Shock Due to Cardiac Diseases: Cardiogenic Shock
Shock due to cardiac diseases is also called cardiogenic shock.
Types of Cardiogenic Shock
- Shock due to arrhythmia (abnormal heart beat).
- Shock due to myocardial ischemia.
- Shock due to congestive heart failure.
IV. Shock Due to Obstruction of Blood Flow: Obstructive Shock
Shock developed due to the obstruction to blood flow through circulatory system is called obstructive shock.
Causes of Obstructive Shock
- Tumor in myocardium.
- Cardiac tamponade (compression of heart due to accumulation of fluid in pericardial space).
- Obstruction of blood vessels in lungs due to embolism.
Syncope or Fainting
Syncope or fainting is the sudden and transient (short-time) loss of consciousness and postural tone with spontaneous recovery.
It occurs due to temporary inadequate cerebral blood flow.
Common Types of Syncope
1. Vasovagal Syncope or Emotional Fainting
Fainting is caused by sudden stimulation of vagus nerve.
It is also called neurocardiogenic syncope.
Vasovagal syncope is common in conditions such as severe emotional distress and exertion.
2. Postural Syncope
Postural syncope is the loss of consciousness caused by prolonged standing.
It occurs due to pooling of blood in lower limbs during prolonged standing resulting in decreased blood supply to the brain.
3. Micturition Syncope
It is the fainting during micturition.
It is common in patients who suffer from orthostatic hypotension.
4. Effort Syncope
Fainting caused during exercise or any other strain is called effort syncope.
It is the common symptom in patients with stenosis of semilunar valves.
5. Cough Syncope
This is the fainting while coughing.
Severe cough increases intrathoracic pressure, which reduces the venous return and cardiac output leading to fainting.
6. Carotid Sinus Syncope
Fainting in persons wearing tight collar dress.
Tight collar of the dress exerts pressure over the region of carotid sinus.
This leads to reduction in heart rate, vasodilation and fainting.
Heart Failure
Definition
Heart failure or cardiac failure is defined as a condition during which heart loses the ability to pump sufficient quantity of blood to all parts of the body.
Heart failure may involve left ventricle or right ventricle or both.
Types of Heart Failure
Heart failure may be acute or chronic.
Acute Heart Failure
Acute heart failure is the sudden and rapid onset of signs and symptoms of abnormal heart functions.
Symptoms last for a very short time and the condition improves rapidly.
Chronic Heart Failure
Chronic heart failure is the heart failure characterized by symptoms that appear slowly over a period of time and become worse gradually.
Congestive Heart Failure
It is the heart failure resulting in accumulation of fluid in lungs and other tissues.
When heart is not able to pump blood through aorta, the blood remains in heart.
It results in dilatation of the chambers and accumulation of blood in veins (vascular congestion).
This condition is also manifested by fluid retention and pulmonary edema.
Common Causes of Heart Failure
- Coronary artery disease.
- Defective heart valves.
- Arrhythmia.
- Cardiac muscle disease such as cardiomyopathy.
- Hypertension.
- Congenital heart disease.
- Diabetes.
- Hyperthyroidism.
- Anemia.
- Lung disorders.
- Myocarditis (inflammation of cardiac muscle due to viral infection, drugs, alcohol, etc.).
Signs and Symptoms of Heart Failure
Signs and Symptoms of Chronic Heart Failure
- Fatigue and weakness.
- Rapid and irregular heartbeat.
- Shortness of breathing.
- Fluid retention and weight gain.
- Loss of appetite, nausea and vomiting.
- Cough.
- Chest pain, if developed by myocardial infarction.
Signs and Symptoms of Acute Heart Failure
Signs and symptoms of acute heart failure may be same as chronic heart failure.
But the signs and symptoms appear suddenly and severely.
When heart starts to fail suddenly, the fluid accumulates in lungs causing pulmonary edema.
It results in sudden and severe shortness of breath, cough with pink, foamy mucus and heart palpitations.
It may lead to sudden death, if not attended immediately.
Compensated and Decompensated Heart Failure
Compensated Heart Failure
Compensated heart failure is the heart failure with adequate cardiac output.
Heart tries to maintain cardiac output by normal compensatory mechanisms such as increase in heart rate, increase in force of ventricular contraction and ventricular hypertrophy.
Symptoms are stable and features of fluid retention and pulmonary edema are absent.
Eventually, in most of the patients, heart can no longer meet the demand even by compensatory mechanisms and this condition leads to decompensated heart failure.
Decompensated Heart Failure
Decompensated heart failure is the heart failure with inadequate cardiac output.
It is characterized by deterioration of cardiac function, and sudden and drastic worsening of cardiac function resulting in death.
Stages of Heart Failure
Heart failure occurs in four stages:
Physical activities can be performed without any symptom.
Heart has no structural changes but there is high risk of heart failure.
Structural changes develop in heart muscle without any symptom.
Characterized by heart disease with symptoms.
Physical activities are limited.
Patients have advanced heart disease with severe symptoms even during resting conditions.
This is the final stage of heart failure.
Quick Revision
Hemorrhage
- Excess loss of blood due to rupture of blood vessels.
- Five categories are described in the source.
- Acute hemorrhage → sudden loss of large quantity of blood.
- Chronic hemorrhage → loss of blood over a long period.
- Acute hemorrhage may cause hypovolemic shock.
- Chronic hemorrhage may produce anemia.
Circulatory Shock
- Developed by inadequate blood flow throughout the body.
- Life-threatening condition.
- Four types are described.
- Hypovolemic shock.
- Vasogenic shock.
- Cardiogenic shock.
- Obstructive shock.
Syncope
- Sudden and transient loss of consciousness and postural tone.
- Occurs due to temporary inadequate cerebral blood flow.
- Vasovagal syncope.
- Postural syncope.
- Micturition syncope.
- Effort syncope.
- Cough syncope.
- Carotid sinus syncope.
Heart Failure
- Heart loses ability to pump sufficient blood to all parts of body.
- May be acute or chronic.
- May involve left ventricle, right ventricle or both.
- Congestive heart failure involves fluid accumulation.
- Heart failure occurs in four stages.