Medical Emergencies CEN Study Guide

Medical Emergencies CEN Study Guide

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CEN Study Guide often emphasizes prioritization and delegation, skills that are crucial for safe and effective nursing care.

Medical Emergencies CEN Study Guide

Allergic reactions and anaphylaxis

  1. Atopic and allergic reactions fall under type 1 hypersensitivity reactions, which are mediated by the IgE immune response.
  2. Examples of atopic disorders include atopic dermatitis, urticaria, angioedema, latex allergies, allergic rhinitis, etc.
  3. Anaphylaxis is an acute and life-threatening form of the IgE-mediated hypersensitivity reaction.
  • The causes include allergens in drugs such as insulin, beta-lactam antibiotics, and streptokinase, foods such as nuts, eggs, and seafood, latex, animal venom, any blood transfusion.
  • Clinical features range from urticaria, flushing, pruritus, rhinorrhea, diarrhea, dizziness, syncope and wheezing to serious complications like shock, angioedema, cyanosis and respiratory failure.
  • Treatment: Start with IV epinephrine. Provide acute resuscitation using IV fluids, oxygen, and vasopressors as needed. For itching (pruritus), give oral antihistamines. Use nebulized beta-agonists to address respiratory symptoms.

Hematologic Disorders

Hemophilia

  • Von Willebrand Disease: This is a bleeding disorder caused by a deficiency in the Von Willebrand factor. It is different from hemophilia. The initial screening may reveal a slightly extended PTT with a normal platelet count.
  • Diagnosis: It is confirmed by low Von Willebrand factor levels.
  • Treatment:

Hemophilia A: It is treated with factor VIII replacement.
Hemophilia B: It is treated with factor IX replacement.
Von Willebrand Disease: The options include desmopressin and Von Willebrand factor concentrates.

  • Other Coagulation Disorders: Examples are hemophilia A and B, which are genetic bleeding disorders that result from deficiencies in factor VIII or IX. Diagnostic indicators include an extended PTT but normal prothrombin time and platelet count. The deficiency is confirmed by the lack of clotting factor/IX. The primary treatment is the replacement of the missing clotting factor.

Thrombocytopenia

This refers to a diminished platelet count in the blood. The causes are diverse and include reduced or absent megakaryocytes (as observed in myelosuppressive and chemotherapy drugs), leukemias, paroxysmal nocturnal hemoglobinuria, decreased platelet production (as seen in alcohol-induced thrombocytopenia, folate and cobalamin deficiency), myelodysplastic syndromes, and HIV-associated thrombocytopenia.

It also arises due to platelet sequestration in the spleen (as seen in cirrhosis, sarcoidosis and Gaucher disease), myelofibrosis, immunologic platelet destruction (as observed in connective tissue disorders), antiphospholipid antibody syndrome, drug-induced thrombocytopenia, lymphoproliferative disorders, non-immunologic-mediated platelet destruction (as seen in systemic diseases like hepatitis, DIC and pregnancy), hemolytic uremic syndrome, and dilutional causes like massive RBC transfusion.

Leukemia

This includes acute and chronic lymphocytic leukemia and acute and chronic myeloid leukemia.

  1. These malignancies predominantly involve white blood cells.
  2. The risk factors include exposure to ionizing radiation, atomic bombs, chemicals

like pesticides and benzene, previous treatment with antineoplastic drugs, certain genetic conditions like Fanconi anemia, Down syndrome, Bloom syndrome, ataxia-telangiectasia, viral infections with Epstein-Barr, and a history of hematologic disorders like myelodysplastic and myeloproliferative syndromes.

Sickle cell crisis

Sickle cell disease is a hemoglobinopathy that is indicated by chronic hemolytic anemia. A sickle cell crisis refers to episodes of pain and other symptoms that are caused by the disease.

  • Sickle cell disease is an autosomal recessive condition that results in the formation of sickle-shaped red blood cells that adhere to each other and cause blood vessel occlusion. These red blood cells are prone to hemolysis, which causes chronic hemolytic anemia in patients.
  • Clinical features include chronic anemia, vaso-occlusive crisis, organ ischemia and significant systemic complications.
  • The diagnosis is made through electrophoresis and sickling tests.

The treatment is done with blood transfusion, proper hydration, antibiotics, effective pain relief and prophylactic hydroxyurea use. The definitive treatment is through bone marrow transplantation.

Electrolyte and Fluid Imbalance

  1. Hyperkalemia- This occurs due to acute kidney injury, chronic kidney injury, the use of potassium-sparing diuretics, rhabdomyolysis, burns, and hemolysis.
  2. Hypokalemia- This results from causes like gastroenteritis, laxative abuse, malabsorption, fistula, colostomy, hyperglycemia, hyperaldosteronism, renal tubular acidosis, metabolic alkalosis, total parenteral nutrition, dialysis, and plasmapheresis.
  3. Hypernatremia- This develops due to dehydration, iatrogenic causes, excessive sodium intake, Cushing syndrome, hyperaldosteronism, peritoneal dialysis, vomiting, diarrhea, fistula, diabetes insipidus, and osmotic diuresis (as seen in alcohol intoxication, burns, etc.).
  4. Hyponatremia- This results from conditions like chronic kidney diseases, cirrhosis, heart failure, diuretic therapy, mineralocorticoid deficiency, SIADH, burns, and pancreatitis.
  5. Hypercalcemia- This is usually caused by primary hyperparathyroidism, multiple myeloma, exogenous vitamin D, immobility, thyrotoxicosis, Paget’s disease, vitamin A toxicity, and adrenal insufficiency.
  6. Hypocalcemia- This is associated with vitamin D insufficiency, hypoparathyroidism, malabsorption syndromes, insufficient calcium intake and other causes.
  7. Dehydration- This is classified as mild, moderate, or severe. The causes include metabolic acidosis, hypernatremia, gastroenteritis, hyperpyrexia, burns, and" heatstroke.
  8. Edema- This occurs due to conditions such as congestive heart failure, liver failure, kidney diseases, and nephrotic syndrome.

Endocrine Disorders

A. Adrenal

  • Primary Adrenal Insufficiency- This disorder is also known as Addison’s disease.
  1. It usually results from inadequate cortisol secretion by the adrenal cortex.
  2. Clinical features include hypotension, adrenal crisis, hyperpigmentation, fatigue, anorexia, vomiting, and diarrhea. The diagnosis relies on clinical assessment and is confirmed through cortisol and ACTH assay. The treatment is done by treating the underlying cause.
  • Cushing Syndrome- This includes a group of clinical features that are caused by prolonged elevated levels of corticosteroids/cortisol. Cushing’s disease is a subset of Cushing's syndrome.
  1. Excess ACTH secretion from a pituitary adenoma causes Cushing’s disease, while exogenous corticosteroid intake is one of the many causes of Cushing's syndrome.
  2. Clinical features include truncal obesity, moon face, striae, easy bruising, hyperglycemia, and thin extremities.
  3. The diagnosis is based on clinical evaluation and confirmed by serum cortisol assay.
  4. The treatment addresses the underlying cause.

B. Glucose-Related Conditions

  • Type l Diabetes Mellitus- This condition is also known as insulin-dependent diabetes mellitus.
  1. It results from the progressive destruction of B cells in the endocrine pancreas.
  2. Clinical features include hyperglycemia, polyuria, polydipsia, polyphagia, cachexia, glucosuria and ketonuria. Diabetic ketoacidosis is a commbn complication.
  3. The treatment involves exogenous insulin administration.
  • Type 2 Diabetes Mellitus- It is often referred to as noninsulin-dependent diabetes mellitus.
  1. It is caused by reduced insulin sensitivity, increased insulin resistance, hyperinsulinemia and endocrine pancreas burnout.
  2. It is predominantly seen in adults but is increasingly prevalent in younger populations due to obesity.
  3. The management strategies include glucose monitoring, education, dietary changes, exercise and medications.

C. Thyroid

  • Hyperthyroidism- This occurs when there is excessive thyroid hormone secretion due to intrinsic thyroid gland dysfunction (primary hyperthyroidism) or hypothalami-pituitary pathway dysfunction (secondary hyperthyroidism).
  1. The main causes include thyroiditis, Graves’ disease and multinodular goiter.
  2. The secondary causes include TSH-secreting adenoma, choriocarcinoma, hydatidiform moles, stroma ovarii, and testicular carcinoma.
  3. The symptoms are weight loss, fatigue, diarrhea, palpitations, and tremors.
  4. The diagnosis is confirmed by thyroid function tests.
  5. The treatment varies based on the underlying cause.
  • 2. Hypothyroidism- This is basically reduced thyroid hormone secretion.
  1. The primary causes include Hashimoto’s thyroiditis, iodine deficiency and lithium use.
  2. Secondary hypothyroidism results from insufficient thyrotropin-releasing hormones and thyroid-stimulating hormone secretion.
  3. Clinical features include dry skin, weight gain, constipation, and hoarseness.

Immunodeficiency

  1. Primary Immunodeficiency- This is genetically driven and is often evident in infancy or early childhood. It results from inborn metabolic errors that impact cellular immunity, humoral immuriity, complement proteins, and phagocytes.
  2. Secondary Immunodeficiency- This stems from systemic disorders such as diabetes, HIV infections, malnutrition, immunosuppressant usage, and chronic illnesses. Other cases may arise after transplantation or chemotherapy.

Renal Failure

  • Acute Kidney Injury- AKI is identified by specific changes in kidney function that occur over a short period of time. There is an increase in serum creatinine (sCr) levels by >0.3 mg/dL (or >26.5 pmol/L) within a 48-hour timeframe. Alternatively, AKI can be indicated by an elevation of Cd levels to >1.5 times the baseline, which is believed to have occurred within the past seven days. Another indicator of AKI is reduced urine output, specifically if it is less than 0.5 mL/kg/hr for a duration of 6 hours.
  • Chronic Kidney Disease (CKD)- This is characterized by five stages:
  1. Stage 1: Normal or high GFR >90 mL/min.
  2. Stage 2: Mild CKD, GFR 60-89 mL/min.
  3. Stage 3A: Moderate CKD, GFR 45-59 mL/min.
  4. Stage 3B: Moderate CKD, GFR 30-44 mL/min.
  5. Stage 4: Severe CKD, GFR 15-29 mL/min.
  6. Stage 5: End-stage CKD, GFR <15 mL/min.
  • End-Stage Renal Disease- ESRD is the final stage of chronic kidney disease (stage 5 CKD). The management of ESRD usually involves hemodialysis, a process that utilizes a dialyzer to filter the patient’s blood. This dialysis can be administered either continuously or intermittently. Continuous hemodialysis is particularly beneficial for patients with acute kidney injury as it reduces the risk of hypotension. 

The main objectives of hemodialysis are to correct electrolyte and fluid imbalances, remove toxins and wastes from the bloodstream, and extend the patient’s survival. Additionally, hemodialysis helps to prevent complications from uremia and improves blood pressure.

  • Peritoneal Dialysis- This dialysis uses the peritoneum as a permeable membrane for blood filtration. This is less taxing for patients compared to hemodialysis since it allows mobility, and home-based performance and has no intravascular access requirement.
  • Renal Transplant- A renal transplant is a medical procedure that is often recommended for patients who have end-stage renal disease. After the transplant, the survival rate during the first year is notably high. Specifically, transplants that are sourced from living donors have a post-first-year survival rate of 98%. In contrast, those from deceased donors have a slightly lower survival rate of 95%.

Sepsis

  1. Sepsis is a life-threatening organ dysfunction that is caused by an overwhelming infection. It reduces tissue perfusion and causes multi-organ failure. The signs of septic shock include fever, hypotension, oliguria, and altered sensorium.
  2. Immunocompetent patients are commonly infected by gram-negative and gram-positive bacteria.
  3. Immunocompromised patients face atypical bacterial and fungal infections.
  4. Septic shock is a severe condition that arises from sepsis. It is characterized by persistent hypotension that necessitates the use of vasopressors. Even after resuscitation, patients with septic shock often exhibit lactate levels that are greater than 2mg/dL.
  5. The treatment options include aggressive resuscitation, antibiotics, fluids, supportive therapy, pus drainage, and debridement.

Hypovolemic and Distributive Shock

Hypovolemic shock occurs when blood loss impedes adequate heart pumping, which puts many organs at risk. Distributive shock is related to uneven blood vessel distribution, which limits the blood that can reach organs.

Substance Use and Abuse

  1. Substance-Induced Disorders- These disorders include intoxication, overdose, withdrawal and substance-related psychiatric disorders.
  2. Substance Abuse Disorders- This category covers disorders that manifest as addiction, tolerance, and both physical and psychological dependence on substances.

Withdrawal Syndrome

Opioid

  1. Clinical Features- Patients may have symptoms like anxiety, tachypnea, diaphoresis, rhinorrhea, diarrhea, tremors, tachycardia, hypertension, and cramps. It is usually nonfatal.
  2. Treatment- Medicines such as methadone, clonidine, and naltrexone are used for symptomatic management.

Alcohol

  • Clinical Features- Lots of alcohol consumption can cause a range of clinical symptoms. Mild manifestations include headaches, tremors, weakness, tachycardia, hypertension, gastrointestinal issues, and hyperreflexia. Ifleft untreated, these symptoms can escalate. A condition known as alcoholic hallucinosis may develop, where the patient may experience visual and auditory hallucinations, along with distressing nightmares. The most severe stage is delirium tremens, where the individual may experience anxiety, depression, alterations in personality, a fast heart rate, and an increased body temperature. Severe alcohol withdrawal can cause death.
  • Treatment- Supportive care is necessary for individuals who undergo alcohol withdrawal. Ensure adequate hydration with fluids, provide proper nutrition, and manage the body temperature if it is too high. Furthermore, benzodiazepines can be administered to help with sedation during the withdrawal process.

Anxiolytic

  1. Clinical features- Withdrawal symptoms from benzodiazepines are non-life-threatening. Barbiturate withdrawal can mimic life-threatening symptoms like delirium tremens. Benzodiazepine withdrawal features include tachycardia, tachypnea, hyperpyrexia, and seizures. Barbiturate withdrawal features include restlessness, increasing anxiety, hyperreflexia, muscle weakness, delirium, seizures that progress to status epilepticus, insomnia, auditory/visual hallucinations, and death.
  2. Treatment- The treatment usually involves supportive care in the ICU. Administer long-acting benzodiazepines to manage symptoms.

Nicotine

  • Clinical features- Nicotine causes strong physical dependence, irritability, poor concentration, anxiety, depression, insomnia, hunger, GI disturbances, headaches, and weight gain.
  • Treatment- The most common treatment options are Bupropion SR, varenicline, and nicotine replacement therapy.

Cannabis

  • Although the withdrawal symptoms of cannabis are generally mild, this is attributed to its limited profound physical dependence. The main dependence on cannabis tends to be more psychological in nature.
  • Clinical features- Those who attempt to reduce or cease their cannabis use may experience symptoms like insomnia, nausea, irritability, anorexia, and depression.
  • Treatment- Most cases only require supportive management, and intensive treatments are reserved for severe cases.

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