Understanding Lupus

Systemic lupus erythematosus is a chronic inflammatory autoimmune disorder of the connective tissue affecting multiple organs. It is characterized by recurring remissions and exacerbations which predominantly affecting women.

How it happens?

• Immune dysregulation in the form of autoimmunity 
• B-cell hyperactivity 
• Causing body to produce antibodies against its own cell components 
• Activation of immune response by formed antigen-antibody complexes 
• Production of antibodies against many different tissue components (RBCs, neutrophils, platelets, lymphocytes) or almost any organ or body tissue 
• Widespread degeneration of connective tissue 
• Possible cardiovascular, renal, and neurologic complication 
• Severe bacterial infections

Understanding Lyme Disease

Lyme disease is a multi-systemic disorder caused by Borrelia burgdorferi, a spirochete transmitted through tick bite. This primarily occurs in areas inhabited by small deer ticks (Ixodes dammini). The disease typically manifests in three stages: early localized stage is characterized by a distinctive red rash accompanied by flulike symptoms; early disseminated stage is characterized by neurologic and cardiac abnormalities; and the late stage is characterized by arthritis, chronic neurologic problems.

How it happens? 

• Tick injects spirochete-laden saliva into host’s bloodstream 
• After 3 to 32 days of incubation 
• Spirochetes outward causing characteristic red macule or papule rash (erythema chronicum migrans) 
• Spirochetes disseminate to other skin sites or organs through bloodstream or lymph system 
• Spirochetes may survive for years in joint, or they may trigger inflammatory response in host and die.

Understanding Pulmonary Embolism

Pulmonary embolism is the obstruction of pulmonary arterial bed by dislodged thrombus, heart valve growth, or foreign substance. This is considered as the common pulmonary complication in hospitalized patients, usually fatal with massive embolism.

How does pulmonary embolism happen?

• Blood clot forms in the deep venous system 
• Clot dislodges and travels through the systemic venous system, right chambers of the heart, and into the pulmonary circulation 
• Clot lodges in a branch of the circulatory system 
• Blood flow distal to obstruction is blocked 
• Embolus prevents alveoli from producing enough surfactant to maintain alveolar integrity 
• Alveoli collapse and atelectasis develops 
• Large clot can cause tissue death.

Understanding Hypovolemic Shock

In hypovolemic shock, there is a reduced intravascular blood volume which causes circulatory dysfunction and inadequate tissue perfusion. This requires early recognition and prompt treatment to improve prognosis.

How does this happen?

• Internal or external fluid loss 
• Decreased intravascular fluid volume 
• Diminished venous return 
• Reduced preload (filling pressure) 
• Decreased stroke volume 
• Lowered cardiac output 
• Reduced mean arterial blood pressure 
• Decreased tissue perfusion 
• Reduced oxygen and nutrient delivery to cells 
• Multiple-organ-dysfunction syndrome.

Understanding Heart Failure

Heart failure is a syndrome that occurs when heart can’t pump enough blood to meet the body’s metabolic needs. This results in intravascular and interstitial volume overload and poor tissue perfusion. It may be classified according to side of heart affected, either left-sided or right-sided heart failure, or cardiac cycle involved (systolic or diastolic dysfunction).

How does this happen?

LEFT-SIDED HEART FAILURE

• Ineffective left ventricular contractility 
• Reduced left ventricular pumping ability 
• Decreased cardiac output to body 
• Blood backup into left atrium and lungs 
• Pulmonary congestion, dsypnea, activity intolerance 
• Pulmonary edema and right-sided heart failure.

RIGHT-SIDED HEART FAILURE

• Ineffective right ventricular contractility 
• Reduced right ventricular pumping ability 
• Decreased cardiac output to lungs 
• Blood backup into right atrium and peripheral circulation 
• Weight gain, peripheral edema, engorgement of kidneys and other organs.

Understanding Hyperthyroidism

Hyperthyroidism is a metabolic imbalance which results from overproduction of thyroid hormones. It is also known as thyrotoxicosis. In Grave’s disease, which is its common form, there is an increase of thyroxine (T4) production that causes an enlargement of the thyroid gland (goiter) and multiple system changes. In thyroid storm, which is the acute and sever exacerbation of thyrotoxicosis (which is a medical emergency), possible life-threatening cardiac, hepatic, or renal consequences occur.

How does this happen?

• T-cell lymphocytes become sensitized to thyroid antigens and stimulate B-cell lymphocytes to secrete autoantibodies 
• Thyroid-stimulating antibodies bind and stimulate thyroid-stimulating hormone (TSH) receptors of the thyroid gland 
• The stimulation increases production of thyroid hormone and cell growth

UNDERSTANDING FOLIC ACID DEFICIENCY ANEMIA

This type of anemia is a common and slow progressive megaloblastic anemia which is marked by a production of few, large, and deformed Red Blood Cells. This is prevalent in infants, adolescents, pregnant and lactating females, alcoholics, elderly, and those with malignant or intestinal disease.

How it happens?

• Insufficient folic acid intake of less than 50 mcg/day, or impairment of intestinal absorption
• Depleted body stores in liver à Inhibition of Red Blood Cells 
• Production of few, deformed Red Blood Cells with shortened life span.

UNDERSTANDING CARDIOGENIC SHOCK

Cardiogenic shock is a condition of diminished cardiac output that severely impairs tissue perfusion. Sometimes it is called pump failure.

How it happens? Occurs in two parts:

• Initial insult 
• Decreased myocardial contractility 
• Decreased stroke volume 
• Decreased left ventricular emptying 
• Left ventricular dilation and backup of blood 
• Increased preload 
• Pulmonary congestion

AND...

• Initial insult 
• Decreased myocardial contractility 
• Decreased stroke volume 
• Increased heart rate 
• Decreased coronary artery perfusion and collateral blood flow 
• Myocardial hypoxia 
• Decreased cardiac output 
• Compensation 
• Decompensation and death.

UNDERSTANDING CHRONIC RENAL FAILURE

Chronic renal failure is the usual end result of gradual tissue destruction and loss of renal function. It may also result from the rapid progressing disease of sudden onset that destroys nephrons and causes irreversible kidney damage. There are manifestations of few symptoms from less than ¼ of glomerular filtration remains. This consists of normal parenchyma then deteriorates rapidly then symptoms worsen as renal function decreases. This is very fatal without treatment and only dialysis or kidney transplant can sustain life.

How does this happen?

• Decreasing number of functioning nephrons 
• Increased solute load from each nephrons à Alteration in GFR 
• Reduced renal reserve: GFR of 35% to 50% of normal (No signs of impaired renal function) 
• Renal insufficiency: GFR of 20% to 35% of normal (Possible hypertension, azotemia, and anemia) 
• Renal failure: GFR of 20% to 25% of normal (Uremia, neurologic, cardiovascular, and GI symptoms) 
• End-stage renal failure: GFR less than 20% of normal (Atrophy and fibrosis in renal tubules).

UNDERSTANDING ALS

Are you a Doctor House fan, or perhaps a Gray’s Anatomy fanatic? If you have seen a couple of those movie series, then probably you’ve encountered some of the characters in the movie mentioning ALS. What is ALS? Amyotrophic lateral sclerosis (ALS) is a chronic progressively debilitating disease – also known as Lou Gehrig disease, which is the most common form of motor neuron disease causing muscular atrophy. This usually occurs to ages between 40 and 60, and twice as common in men than in women.

ALS progressively destroys upper and lower neurons including anterior horn cells of the spinal cord, upper motor neurons of the cerebral cortex, and the motor nuclei of the brain.

How does ALS happen?

• ALS may begin when glutamate accumulates to toxic levels at synapses 
• Affected motor units are no longer innervated 
• Progressive degeneration of axons causes loss of myelin 
• Non-functional scar tissue replaces normal neuronal tissue 
• Denervation leads to muscle fiber atrophy and motor neuron degeneration.

Note: Glutamate is the primary excitatory neurotransmitter of central nervous system.

UNDERSTANDING PERICARDITIS

Pericarditis is also known as the inflammation of the pericardium. 

In acute pericarditis, the pericardium can be fibrous or effusive with purulent, serous, or hemorrhagic exudates. In chronic pericarditis, it is seen as dense, thick, and fibrous pericardium.

How it happens?

• Bacteria or other substances damage pericardial tissue 
• Bradykinins, histamines, prostaglandins, and serotonin are released into the surrounding tissue, thus commencing the inflammatory process  
• Inflamed pericardial layers rub against each other causing friction
• Histamines and other chemical mediators dilate vessels and increase vessel permeability
• Vessel walls leak fluids and protein into tissue causing extracellular edema 
• Macrophages starts to phagocytise invading bacteria joined by neutrophils and monocytes 
• Area fills with exudates composed of necrotic tissue and dead and dying bacteria, neutrophils, and macrophages
• Pericardial effusion develops if fluid accumulates in pericardial cavity.

UNDERSTANDING RHABDOMYOLYSIS

Rhabdomyolysis is characterized by the breakdown of muscle fibers. There is a good prognosis of rhabdomyolysis if the contributing causes are alleviated or the disease is treated before damage becomes irreversible. If this is unchecked, it can cause renal failure.

How does it happen?

• Direct injury to muscle fibers (sarcolemma) 
• Increased intracellular sodium ion concentration 
• Enhanced enzyme activity and interaction between actin and myosin 
• Further muscle damage 
• Leakage of myoglobin, potassium, and creatine kinase into the bloodstream 
• Myoglobin trapped in renal capillaries or tubule 
• Acute renal failure.

A leakage of myoglobin may alter kidney filtration.