Comprehensive

Allergy Pathophysiology and Diagnostic Testing

Allergies are characterized by an overactive immune response accompanied by excessive inflammation, initiated by an allergen. These allergens may be inhaled, ingested, injected, or come into direct contact with the skin. A Type 1 allergic response is a classic anaphylactic reaction triggered by substances such as latex, bee venom, peanuts, iodine, and shellfish. Angioedema is a specific Type 1 response involving blood vessels and affects all layers of the skin, mucous membranes, and subcutaneous tissue, most prominently appearing in the lips, face, tongue, larynx, and neck. Anaphylaxis is a severe Type 1 response where bronchiolar smooth muscles and blood vessels are affected, causing widespread blood vessel dilation, decreased cardiac output, and bronchoconstriction. This leads to respiratory compromise, which is the primary emergency concern.

Diagnostic testing for allergies involves skin or blood tests. The intradermal test involves injecting a small amount of antigen; notably, the patient must be off all medications for a period of $7.0\,\text{days}$ prior to the test. Results are evaluated by measuring the size of wheals, which are graded on a scale up to $+4.0$ . Signs and symptoms associated with these responses include rhinorrhea, syncope, urticaria (hives), sneezing, itchy and watery eyes, congestion, excess mucus production, GI symptoms, dyspnea, swelling, hoarseness, a rapid but weak pulse, bronchospasm, stridor, and voice changes.

Nursing interventions for angioedema require asking when the reaction started and if any drugs were taken, as this is an acute emergency. Oxygen ( $O_2$ ) is administered to facilitate gas exchange, and intubation may be necessary if the patient exhibits stridor or an inability to swallow. For anaphylaxis, the nurse must initiate a rapid response, obtain IV access, and prepare intubation equipment. Epinephrine is the $1^{st}$ intervention and can be repeated every $5.0$ to $15.0\,\text{mins}$ . If three doses of intramuscular (IM) epinephrine are ineffective, IV epinephrine is administered. Additional treatments include applying $O_2$ via a non-rebreather mask (NRB), infusing normal saline ( $NS$ ), and elevating the patient's feet. Medications for angioedema include epinephrine and corticosteroids; however, if drugs that shrink edema are stopped, the condition can redevelop. Anaphylaxis treatment involves epinephrine and antihistamines.

Lupus Erythematosus (SLE) Pathophysiology and Management

Lupus is a chronic, progressive autoimmune disorder categorized as a Type 3 allergy. It is inflammatory in nature, with the immune system attacking multiple tissues and organs, leading to a loss of tissue integrity. The disease follows a pattern of exacerbations (flares) and remissions. Diagnostic tests focus on the presence of autoantibodies and conditions that accompany Systemic Lupus Erythematosus (SLE), such as anemia, leukopenia, and kidney dysfunction. Useful tests include Erythrocyte Sedimentation Rate ( $ESR$ ), Complete Blood Count ( $CBC$ ), electrocardiogram ( $ECG$ ), Computed Tomography ( $CT$ ), and Magnetic Resonance Imaging ( $MRI$ ). Risk factors contributing to SLE include viral infections, drugs, hormones, sun exposure (UV rays), and chemotherapy.

Signs and symptoms of lupus include chronic fatigue, alopecia, vasculitis, cardiovascular impairment, muscle aches, osteoporosis, vision changes, anemia, and oliguria. A characteristic butterfly rash is often observed. Joint pain is generalized but most commonly affects the feet, ankles, knees, wrists, and fingers, typically occurring bilaterally. Fever is the first sign of an exacerbation. Proteinuria occurs when the glomerulus is damaged, causing protein to filter into and remain in the urine. Other symptoms include pericarditis, friction rubs, and seizures. Complications can include Chronic Kidney Disease ( $CKD$ ) and osteonecrosis.

Nursing interventions involve noting physical changes over the past $5.0\,\text{years}$ , assessing for painful or swollen joints, and monitoring blood pressure, heart rate, and pulse quality. Patients should avoid large crowds to reduce infection risk. Medications include acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen, ibuprofen, indomethacin, and celecoxib, which are used daily for pain and inflammation. Aspirin is also used. Corticosteroids are utilized during flares; if a patient already takes them daily, the dose is increased and then tapered down once the flare ends. Short-term side effects of steroids include acne, hypertension ( $HTN$ ), fluid retention, and anxiety, while long-term use leads to weight gain, fragile skin, thin hair, and stretch marks. Patients on corticosteroids should take calcium to prevent osteoporosis. Antimalarial drugs like hydroxychloroquine provide immunomodulatory and anti-clotting effects; patients on this drug require eye exams before starting and every $6.0\,\text{months}$ thereafter. Belimumab is another option, though patients must not receive live vaccines for $30.0\,\text{days}$ prior to treatment. Education for lupus patients includes ensuring proper rest, avoiding stress, engaging in low-impact activities, limiting sun exposure with sunscreen and protective clothing, and using moist heat for pain. Patients are advised not to get pregnant.

Lyme Disease Stages and Prevention

Lyme disease is characterized by chronic inflammation triggered by the release of cytokines following a tick bite from a spirochete. Stage $1$ (early localized) presents with a bull's eye rash and low-grade fever within $3.0$ to $30.0\,\text{days}$ post-bite. Stage $2$ (early disseminated) occurs $3.0$ to $12.0\,\text{weeks}$ later if treatment is ineffective, presenting with pain in the ankles, knees, and wrists, as well as dysrhythmias, palpitations, dyspnea, and flu-like symptoms. Stage $3$ (late stage) involves arthritis, continued dysrhythmias, heart block, and cognitive deficits.

Prevention and nursing interventions include using $DEET$ , avoiding heavily wooded areas, and wearing light-colored clothing with long sleeves and pants. Closed-toe shoes should be worn, and individuals should bathe immediately after a tick is removed. Ticks should be disposed of with alcohol or by flushing. Medications for Lyme disease include doxycycline, amoxicillin, or cefuroxime for a duration of $14.0$ to $21.0\,\text{days}$ . In some cases, IV antibiotics are necessary.

HIV and AIDS Pathophysiology and Clinical Care

Human Immunodeficiency Virus (HIV) is a retrovirus that inserts viral RNA into a host cell, converting it into viral DNA. It utilizes $CD4$ cells to replicate, producing up to $10.0 \times 10^9$ particles per day. This causes $CD4$ counts to decrease while the viral load increases, weakening the immune system. Transmission occurs through all bodily fluids. HIV is classified in stages based on $CD4$ counts: Stage $1$ (Acute) is confirmed HIV with $CD4 > 500.0$ ; Stage $2$ (Chronic) is confirmed HIV with $CD4$ between $200.0$ and $499.0$ ; Stage $3$ (AIDS) is confirmed HIV with $CD4 < 200.0$ or a documented AIDS-defining illness. Diagnostic tests include the ELISA to detect HIV antibodies, which must be confirmed with a Western blot. Together, these tests are $99.9\,\%$ accurate. Viral load and CBC are also monitored; a high viral load indicates high transmission risk.

Signs and symptoms of acute HIV include fever, chills, headache, night sweats, muscle aches, rash, and sore throat. Opportunistic infections commonly seen include Candidiasis (thrush, mouth pain, difficulty swallowing), Cryptosporidiosis (severe intestinal infection, diarrhea, electrolyte monitoring), Toxoplasmosis (from cat feces or undercooked meat, causes altered mental status and seizures), Pneumocystis jirovecii pneumonia (PCP/PJP, dry cough, tachypnea, fatigue, crackles), Histoplasmosis (respiratory infection, dyspnea, fever), and Tuberculosis ( $TB$ ). Kaposi's Sarcoma (KS) presents as pink, red, purple, or brown lesions with a yellow halo.

Nursing interventions include collecting a thorough history in private, assessing for opportunistic infections (e.g., lung sounds for PCP, Level of Consciousness ( $LOC$ ) and Head of Bed ( $HOB$ ) at $30.0^{\circ}$ for Toxoplasmosis), and implementing airborne precautions for $TB$ . Infection prevention is critical: patients should wash hands, avoid crowds, take their temperature daily, and avoid digging in dirt. Dietary requirements include high protein and high calorie intake, with supplements as needed. Fruits and vegetables must be washed and food properly refrigerated. For thrush, the tongue should be brushed with a soft toothbrush. Antiretroviral medications control viral replication but do not kill the virus; side effects include appetite loss, diarrhea, fatigue, increased cholesterol, mood changes, nausea, and insomnia. Skipping doses can lead to drug resistance. Other medications include gabapentin for pain, bronchodilators, glucocorticoids, and Trimethoprim/Sulfamethoxazole for prophylaxis.

Thermal Emergencies: Heat Stroke and Hypothermia

Heat stroke is a medical emergency where the body temperature may exceed $104.0^{\circ}F$ . Thermoregulation fails and cannot adjust for the elevation in temperature. Signs include hot/dry skin, tachypnea, tachycardia, hypotension, anxiety, confusion, coma, seizures, and abnormal clotting. Lab values may show electrolyte imbalances and renal dysfunction. Nursing interventions include ensuring a patent airway, removing the patient from the heat and removing clothes, spraying the patient with cold water, fanning, and placing cold packs. In the hospital, oxygen is given, an IV started, and a cooling blanket used. No aspirin or antipyretics should be given. Continuous temperature monitoring via catheter is required, along with ABGs and I/Os. Cooling must stop once the temperature reaches $102.0^{\circ}F$ .

Hypothermia occurs when the core temperature is $95.0^{\circ}F$ or lower, often caused by cold water, acute illness, shock, or hypothyroidism. It is staged as Mild ( $90.0^{\circ}F$ – $95.0^{\circ}F$ : shivering, slurred speech, confusion), Moderate ( $82.4^{\circ}F$ – $90.0^{\circ}F$ : muscle weakness, loss of coordination, impaired cognition, diuresis), and Severe ( $< 82.4^{\circ}F$ : bradycardia, hypotension, dysrhythmias, decreased neuro-responsiveness). Labs may show acid-base and electrolyte imbalances, clotting issues, and renal failure. Interventions include positioning the patient supine, monitoring temperature, and administering drugs with caution due to unpredictable metabolism. Passive and active rewarming includes heated blankets, warm liquids with high carbohydrates, warm IV fluids, heated $O_2$ , and heated bladder/GI lavage. Drugs (except pressors) should be withheld until the temperature exceeds $86.0^{\circ}F$ . The trunk must be warmed before the extremities.

Frostbite occurs when body tissue freezes. It presents with a white-waxy appearance. At the scene, jewelry and constricting items should be removed, and the area placed in a warm spot (like underarms). In the hospital, rapid rewarming is performed, and IV pain relief is administered. The area should be handled gently and elevated above the heart. Dry heat and massage are strictly avoided. Tetanus vaccines are given, and loose, non-adherent sterile dressings are applied without compression.

Lightning and High Altitude Injuries

Lightning injuries can occur via direct strikes, splashing off objects, or traveling through the ground. Symptoms include confusion, coma, temporary paralysis, cardiac arrest, and CNS abnormalities. At the scene, spinal stabilization and airway management are priorities; victims are not electrically charged. In the hospital, management includes advanced life support ( $ALS$ ), a $12$ -lead $ECG$ , $CT$ scans, and wound assessment. A major complication is rhabdomyolysis, the circulation of by-products from skeletal muscle destruction, which leads to renal failure and tea-colored urine. Prevention involves crouching on the balls of the feet and tucking the head if lightning is imminent, staying away from metal and plumbing, and turning off electrical equipment.

High altitude illness ( $1500.0\,\text{meters}$ or more) is managed by acclimatization, where the body adapts to lower $O_2$ pressure through a hypoxia-ventilatory response. This increases heart rate and cardiac output ( $CO$ ), and kidneys excrete excess bicarbonate ( $HCO_3^{-}$ ) to manage respiratory alkalosis within $24.0$ to $48.0\,\text{hours}$ . Common conditions include Acute Mountain Sickness (AMS: headache, nausea), High Altitude Cerebral Edema (HACE: ataxia, confusion, seizures, coma), and High Altitude Pulmonary Edema (HAPE: poor exercise tolerance, persistent dry cough, cyanosis, crackles, pink frothy sputum). Treatments include moving to a lower altitude and administering $O_2$ . Medications include Acetazolamide to treat AMS, Dexamethasone for cerebral edema, and Phosphodiesterase inhibitors (tadalafil, sildenafil) or Nifedipine for pulmonary edema.

Organ Transplantation Protocols

Organ-specific preservation times outside the body vary: lung ( $4.0$ – $6.0\,\text{hours}$ ), heart ( $4.0$ – $5.0\,\text{hours}$ ), liver ( $24.0$ – $30.0\,\text{hours}$ ), and kidney ( $48.0$ – $72.0\,\text{hours}$ ).

Lung transplant candidates must have severe irreversible damage but otherwise be healthy. Exclusions include cancer, HIV, or irreversible damage to other organs. Post-op, patients are usually intubated for at least $48.0\,\text{hours}$ with chest tubes. Immediate antirejection drugs are required for life, though corticosteroids are avoided for the first $10.0$ to $14.0\,\text{days}$ . Heart transplant candidates must have a life expectancy $< 1.0\,\text{year}$ , be $< 65.0\,\text{years}$ old, and have stable psychosocial status. The new heart is denervated, making it unresponsive to vagal stimulation. Atropine and digoxin are avoided; Isoproterenol supports heart rate. Orthostatic hypotension is common. Biopsies are performed regularly.

Liver transplant is commonly for cirrhosis. Complications include rejection (tachycardia, fever, RUQ pain, jaundice, increased bilirubin) and obstruction. Nursing interventions include monitoring temp, abdominal pain, and neuro status. Kidney transplant candidates require dialysis within $24.0\,\text{hours}$ of surgery and may receive a transfusion. Post-op, urine may be pink or bloody; hourly I/O monitoring is vital. Rejection is diagnosed through symptoms, ultrasound, or biopsy. Hyperacute rejection occurs within $48.0\,\text{hours}$ (necrosis); Acute rejection occurs within the first $3.0\,\text{months}$ (fever, fatigue, tenderness) and is treated with rescue therapy (high-dose steroids).

Cancer Types, Warning Signs, and Prevention

Cancer involves malignant cells that are migratory, allowing for metastasis. Primary tumors are identified by the tissue of origin; secondary tumors are metastatic. Risk factors include chemical, physical (UV, radiation), viral (DNA breakdown), and dietary factors (excess animal fat, nitrates, red meat). Primary prevention includes smoking cessation, removing "at-risk" tissue (moles, polyps), chemoprevention (Tamoxifen), and vaccinations (HPV). Secondary prevention involves screenings: mammograms (yearly if $> 40.0$ or $45.0$ – $54.0$ ), Pap smears (every $3.0\,\text{years}$ for ages $21.0$ – $29.0$ ), colonoscopy (starting at $50.0$ every $10.0\,\text{years}$ ), and fecal occult blood tests annually. The "CAUTION" warning signs are: Change in bowel habits, A sore that doesn't heal, Unusual bleeding, Thickening/lumps, Indigestion, Obvious change in mole, and Nagging cough.

Treatment modalities include surgery (prophylactic, diagnostic, debulking, curative, palliative, or reconstructive) and radiation. External beam radiation involves marking the skin. Brachytherapy is internal radiation where the source directly contacts the tumor; while the source is in place, the patient is radioactive. Skin care for radiation involves washing with mild soap and water daily, patting dry, and avoiding friction or sun exposure for $1.0\,\text{year}$ . Chemotherapy is used to improve survival but is not a cure for metastatic disease. It must not be given through a peripheral IV. Side effects include cardiac damage and neutropenia. For neutropenia, patients must avoid crowds, take temperature daily (report $> 100.4^{\circ}F$ ), and wash fruits/veg. For thrombocytopenia (platelets $< 50,000.0$ ), avoid trauma, IM injections/venipunctures, and use soft toothbrushes.

Specific Cancers and Oncologic Emergencies

Head and Neck cancers are typically slow-growing squamous cell carcinomas. Warning signs include oral lesions not healing in $2.0\,\text{weeks}$ , persistent ear pain, and neck lumps. Colorectal cancer commonly metastasizes to the liver; the most common sign is rectal bleeding. Breast cancer screening includes mammograms and monthly self-exams $7.0\,\text{days}$ after a period. Cervical cancer is often linked to HPV and presents as painless vaginal bleeding. Prostate cancer is associated with advanced age; screening includes PSA (glycoprotein) and rectal exams. Testicular cancer is common in younger men and presents as painless enlargement.

Oncologic emergencies include:

Hypercalcemia: From bone metastasis; treated with IV hydration and loop diuretics (avoid thiazides). BISphosphonates provide relief.
Spinal Cord Compression: Symptoms include back pain, weakness, and loss of sensation; treated with high-dose steroids and radiation.
Superior Vena Cava (SVC) Syndrome: Edema of the face and engorged vessels; treated with stents, anticoagulants, and chemo.
Tumor Lysis Syndrome: Rapid cell destruction leads to high potassium and high uric acid (blocking kidneys). Patients must drink at least $3000.0\,cm^3/\text{day}$ . Allopurinol is used to promote uric acid excretion.

Emergency Nursing and Triage

Emergency department (ED) nurses may specialize in forensics (SANE) or psychiatric crisis. The interprofessional team includes EMTs (basic life support) and Paramedics (advanced life support: intubation, IV access, needle decompression). Patient safety priorities include ID bracelets (two unique identifiers), fall prevention, and skin protection. Staff safety concerns focus on violence and disease transmission.

Triage is a system used to prioritize patients:

Emergent: Immediate threat to life/limb (chest pain, stroke, respiratory distress).
Urgent: Needs quick treatment but not immediately life-threatening (abdominal pain, fractures, renal colic).
Non-urgent: Can wait several hours (simple fractures, rashes, UTIs).

The Primary Survey follows A-B-C-D-E: Airway (protect cervical spine, intubate if GCS $< 8.0$ ), Breathing (assess sounds, chest wall trauma), Circulation (monitor vitals, vascular access, pressure for bleeding), Disability (evaluate LOC with GCS), and Exposure (remove clothes, prevent hypothermia).