PNLE Review: Shock, Burns, and More

• PNLE study notes covering shock, burns, liver failure, GI bleeding, CRF, DM1-2, MI, ARF, ARDS, pulmonary HTN, pneumothorax, pulmonary embolism, pneumonia, and COPD.

Shock

• Shock is inadequate tissue perfusion leading to cellular hypoxia.
• Cardiogenic shock occurs due to heart failure and reduced cardiac output.
• Hypovolemic shock results from decreased intravascular volume.
• Anaphylactic shock is a severe allergic reaction causing vasodilation and increased permeability.
• Septic shock is triggered by infection, leading to systemic inflammation and vasodilation.
• Neurogenic shock results from loss of sympathetic tone, causing vasodilation.

Burns

• Burns are tissue damage resulting from heat, chemicals, electricity, or radiation.
• First-degree burns affect the epidermis, causing redness and pain.
• Second-degree burns involve the dermis, resulting in blisters and intense pain.
• Third-degree burns destroy the epidermis and dermis, often painless due to nerve damage.
• The Rule of Nines estimates the total body surface area (TBSA) affected by burns.
• Fluid resuscitation is crucial in burn management to prevent hypovolemic shock.

Liver Failure

• Liver failure is the liver's inability to perform its normal functions.
• Cirrhosis is a common cause, marked by fibrosis and scarring of the liver.
• Ascites, the accumulation of fluid in the peritoneal cavity, often occurs.
• Hepatic encephalopathy results from the buildup of toxins in the brain.
• Jaundice, yellowing of the skin and eyes, indicates impaired bilirubin metabolism.
• Coagulopathy, impaired blood clotting, is due to decreased production of clotting factors.

GI Bleeding

• GI bleeding is hemorrhage in the gastrointestinal tract.
• Upper GI bleeds often result from peptic ulcers, varices, or Mallory-Weiss tears.
• Lower GI bleeds may be caused by diverticulosis, colitis, or hemorrhoids.
• Hematemesis is vomiting blood.
• Melena is black, tarry stools.
• Hematochezia is bright red blood in the stool.

Chronic Renal Failure (CRF)

• CRF (Chronic Renal Failure), also known as Chronic Kidney Disease (CKD), is the gradual loss of kidney function.
• Common causes include diabetes and hypertension.
• Anemia results from decreased erythropoietin production.
• Electrolyte imbalances, like hyperkalemia and hyperphosphatemia, are common.
• Uremia is the buildup of waste products in the blood.
• Dialysis or kidney transplantation becomes necessary in end-stage renal disease (ESRD).

Diabetes Mellitus (DM) Type 1 and Type 2

• DM1 is an autoimmune destruction of pancreatic beta cells, leading to insulin deficiency.
• DM2 is insulin resistance and progressive loss of beta cell function.
• Hyperglycemia is elevated blood glucose levels.
• Polydipsia is excessive thirst.
• Polyuria is frequent urination.
• Polyphagia is increased hunger.
• Long-term complications include neuropathy, nephropathy, and retinopathy.

Myocardial Infarction (MI)

• MI is a heart attack due to blocked blood flow to the heart muscle.
• Chest pain, often described as crushing or squeezing, is a common symptom.
• ECG changes, such as ST-segment elevation, indicate myocardial injury.
• Cardiac enzymes, like troponin, are elevated in the blood.
• Prompt treatment with thrombolytics or angioplasty is crucial to restore blood flow.

Acute Renal Failure (ARF)

• ARF, also known as Acute Kidney Injury (AKI), is a sudden loss of kidney function.
• Prerenal ARF is due to decreased blood flow to the kidneys.
• Intrarenal ARF is caused by direct damage to the kidneys.
• Postrenal ARF results from obstruction of urine flow.
• Oliguria is decreased urine output.
• Hyperkalemia is a dangerous complication.

Acute Respiratory Distress Syndrome (ARDS)

• ARDS is a severe form of acute lung injury.
• It is characterized by widespread inflammation and increased permeability of the alveolar-capillary membrane.
• Hypoxemia, low blood oxygen levels, is a hallmark of ARDS.
• Pulmonary edema is fluid accumulation in the lungs.
• Mechanical ventilation is often required to support breathing.

Pulmonary Hypertension

• Pulmonary HTN is elevated blood pressure in the pulmonary arteries.
• It leads to right ventricular heart failure (cor pulmonale).
• Shortness of breath and fatigue are common symptoms.
• Diagnosis involves right heart catheterization.
• Treatment includes pulmonary vasodilators and oxygen therapy.

Pneumothorax

• Pneumothorax is air accumulation in the pleural space.
• It causes lung collapse.
• Tension pneumothorax is a life-threatening condition where air accumulates and compresses the heart and great vessels.
• Symptoms include chest pain and shortness of breath.
• Treatment involves chest tube insertion to remove air.

Pulmonary Embolism (PE)

• PE is a blood clot that lodges in the pulmonary arteries.
• It often originates from deep vein thrombosis (DVT) in the legs.
• Symptoms include sudden shortness of breath, chest pain, and cough.
• Diagnosis involves CT angiography or V/Q scan.
• Treatment includes anticoagulants or thrombolytics.

Pneumonia

• Pneumonia is an infection of the lungs.
• It can be caused by bacteria, viruses, or fungi.
• Symptoms include cough, fever, and shortness of breath.
• Chest X-rays show lung infiltrates.
• Treatment involves antibiotics for bacterial pneumonia.

Chronic Obstructive Pulmonary Disease (COPD)

• COPD is a chronic inflammatory lung disease that causes obstructed airflow from the lungs.
• Emphysema, destruction of alveoli, and chronic bronchitis, inflammation of the airways, are common components.
• Smoking is the leading cause.
• Symptoms include chronic cough, sputum production, and shortness of breath.
• Pulmonary function tests are used for diagnosis.
• Treatment includes bronchodilators, inhaled corticosteroids, and oxygen therapy.