Respiratory and Fluid-Electrolyte Nursing Review

Asthma and Lower Respiratory Pathophysiology

• Asthma Overview: A chronic inflammatory lung disease causing airway narrowing, inflammation, and excessive mucus production. It is characterized by reversibility, although the absence of wheezing (a "silent chest") indicates severe obstruction and impending respiratory failure.

• Pathophysiology Details:

  • Bronchi and bronchioles undergo chronic inflammation.

  • Smooth muscle constriction occurs alongside excessive mucus secretion from goblet cells.

  • Airflow reduction leads to air trapping in the alveoli.

  • Carbon Dioxide Retention: Can result in respiratory acidosis ($CO_2$ is acidic).

  • Airway Hyperresponsiveness: Minor triggers incite immediate bronchoconstriction.

• Common Triggers:

  • Allergens: Dust mites, pollen, pet dander.

  • Irritants: Smoke, pollution, cold air.

  • Others: Respiratory infections, exercise, and stress.

• Symptom Severity:

  • Mild-Moderate: Wheezing, shortness of breath (worsened by activity), nocturnal cough, chest tightness, tachycardia, and tachypnea.

  • Severe: Difficulty speaking in full sentences, use of accessory muscles, cyanosis, and altered mental status.

• Nursing Interventions:

  • Monitor peak flow, oxygen saturation ($SpO_2$), and respiratory rate.

  • Positioning: Use Semi-Fowler's or upright sitting to facilitate breathing.

  • Oxygen Therapy: Administer as prescribed to maintain SpO_2 > 92\%.

  • Medication Management:

  • Short-acting beta-agonists ($SABA$) like albuterol for acute relief.

  • Long-acting beta-agonists ($LABA$) or combinations (e.g., salmeterol + fluticasone) for maintenance.

  • Use a spacer with a mask for better delivery and to reduce the risk of oral thrush.

• Acute Bronchiectasis: A sudden exacerbation involving permanent dilation, thickening, and destruction of the bronchi.

  • Characterized by large amounts of thick, foul-smelling sputum and hemoptysis.

  • Physical findings include crackles and finger clubbing.

  • Treatment ($TX$): Antibiotics ($ATB$), $O_2$, and bronchodilators.

Chronic Obstructive Pulmonary Disease (COPD)

• Definition: A progressive, not fully reversible lung disease caused by long-term exposure to irritants (e.g., cigarette smoke, pollution). It typically combines chronic bronchitis and emphysema.

• Chronic Bronchitis ("Blue Bloaters"):

  • Defined as a chronic productive cough for at least $3$ months in $2$ consecutive years.

  • Symptoms: Cyanosis, fluid retention, hypoxia, and frequent infections.

• Emphysema ("Pink Puffers"):

  • Long-term damage to the thin walls of the alveoli.

  • Symptoms: Dyspnea, barrel chest, weight loss, and prolonged expiration.

• Nursing Assessment and Care:

  • Accessory muscle use and tripod positioning are common.

  • Education: Pursed-lip breathing and smoking cessation.

• Pharmacology Note - Fluticasone:

  • A corticosteroid nasal spray ($2$ sprays per nostril daily) or inhaler.

  • Used for allergy symptoms and nasal polyps.

  • Side Effects: Vasodilation may cause nosebleeds. Inhaled versions require rinsing the mouth after use to prevent thrush.

Venous Thromboembolism (DVT and PE)

• Deep Vein Thrombosis (DVT): A blood clot in deep veins (peroneal, posterior tibial, popliteal, femoral).

• Virchow’s Triad (Risk Factors):

  1. Stasis of Venous Circulation: Immobility, surgery, long travel, heart failure, varicose veins.

  2. Endothelial Injury: Trauma, IV catheters, surgery.

  3. Hypercoagulability: Pregnancy, oral contraceptives, cancer, clotting disorders.

• Clinical Presentation:

  • Unilateral leg swelling, warmth, redness, and calf pain (especially with dorsiflexion).

  • Homans' Sign: Pain with dorsiflexion; however, it is unreliable for screening.

  • Diagnostic Significance: A difference in calf circumference > 2\,cm is significant.

• Diagnostics & Interventions:

  • Tests: Duplex ultrasound (confirmation) and D-dimer (screening).

  • Prevention: Early ambulation, sequential compression devices ($SCDs$), compression stockings, and anticoagulants like enoxaparin.

  • Contraindication: Never massage the affected leg as it may dislodge the clot.

• Pulmonary Embolism (PE): Follows the dislodgement of a DVT.

  • Symptoms: Acute onset of dyspnea, pleuritic chest pain, cough, hemoptysis, and palpitations.

  • Signs: Tachypnea, crackles, tachycardia, and an $S_4$ heart sound.

  • Management: Anticoagulation (Heparin bridge to Warfarin), bed rest in the acute phase, and elevation of the affected extremity.

Acute Respiratory Distress Syndrome (ARDS)

• Definition: A life-threatening condition where fluid builds up in the alveoli, causing refractory hypoxemia (low oxygen despite high-flow oxygen therapy).

• Stages of ARDS:

  1. Exudative Stage: Initial fluid accumulation and inflammation.

  2. Proliferative Stage: Partial recovery and lung tissue repair.

  3. Fibrotic Stage: Formation of scar tissue; necessitates prolonged ventilation.

• Clinical Features: Severe dyspnea, tachypnea, anxiety, and crackles on auscultation.

• Intervention: Prone positioning is frequently used to improve oxygenation.

Tuberculosis (TB)

• Pathogen: Mycobacterium tuberculosis.

• Transmission: Airborne droplets. Requires negative-pressure rooms and $N95$ respirators.

• Symptoms: Persistent cough (> 3 weeks), hemoptysis, night sweats, low-grade fever, weight loss, and fatigue.

• Risk Factors: HIV/immunocompromised status, malnutrition, substance abuse, and crowded living conditions.

• Treatment Protocol: Multiple antibiotics for several months.

  • Rifampin: Causes orange-red discoloration of body fluids.

  • Isoniazid: Risk of peripheral neuropathy; often administered with Vitamin $B_6$.

Laryngeal Cancer and Laryngectomy

• Laryngeal Cancer: Affects the larynx and pharynx; risk factors include smoking and alcohol.

  • Symptoms: Persistent hoarseness, difficulty swallowing, chronic cough, and ear pain.

• Laryngectomy: Surgical removal of the voice box.

  • Nursing Priority: Airway management. The patient breathes through a permanent stoma in the neck.

  • Care: Humidification is vital because the nose (which normally humidifies air) is bypassed.

Wound and Post-Anesthesia Care

• Wound Dehiscence: Surgical incision reopens ($5-10$ days post-op). Higher risk in obesity, diabetes, or with excessive straining.

• Evisceration: Internal organs protrude through a dehisced wound.

  • Emergency Action: Stay with the patient, notify the provider, cover the organs with sterile normal saline ($NS$) dressings, and place the patient in Low Fowler's with knees bent.

• PACU Priorities: Stabilization post-anesthesia. Monitoring for respiratory depression (often due to opioids), bleeding, and low blood pressure ($VBP$).

Pain Management and Opioids

• Pain Types:

  • Acute: Short-term; serves as a warning signal (e.g., fractures). Signs include tachycardia ($THR$), increased BP, and guarding. Patient self-report is the most reliable.

  • Chronic: Lasts > 3 months (e.g., arthritis). Goal is quality of life ($QOL$) and function.

• Opioids: Examples include morphine, fentanyl, hydromorphone, and oxycodone.

  • Side Effects: Respiratory depression, constipation, urinary retention, and nausea/vomiting.

  • Monitoring: Hold if respiratory rate is < 12 breaths per minute.

  • PCA Pump: Patient-controlled analgesia. Only the patient should press the button.

• Metastatic Bone Cancer: Leads to deep, persistent pain and pathologic fractures. Can cause hypercalcemia (confusion, constipation, and decreased reflexes).

Fluids, Electrolytes, and Acid-Base Balance

• Respiratory Alkalosis: pH > 7.45 and PaCO_2 < 35\,mm\,Hg. Caused by hyperventilation (anxiety, fever, sepsis). Symptoms include tingling around the mouth and lightheadedness.

• Dehydration (Fluid Volume Deficit):

  • Signs: Thirst, dry membranes, poor turgor, tachycardia, and orthostatic hypotension.

  • Labs: Elevated Hematocrit ($Hct$), $BUN$, and urine specific gravity due to hemoconcentration.

• Hypervolemia (Fluid Volume Excess):

  • Pathophysiology: Isotonic expansion of extracellular fluid ($ECF$) due to sodium and water retention. Secondary to heart failure ($HF$) or kidney failure.

  • Signs: Edema, $JVD$, crackles, weight gain, and increased central venous pressure ($CVP$).

  • Labs: Decreased $Hct$ and $BUN$ (hemodilution).

  • Interventions: Sodium and fluid restriction, diuretics (Furosemide for severe cases; Thiazides for mild), and monitoring for pulmonary edema.

  • Weight Conversion: $2.2\,lb\, (1\,kg) = 1\,L$ of fluid.

• Hypocalcemia: Serum calcium < 8.5\,mg/dL.

  • Signs: Tetany, hyperactive reflexes, muscle cramps.

  • Tests: Positive Chvostek's (facial twitching) and Trousseau's (carpal spasm with BP cuff).

  • Emergency: Monitor for laryngospasm and seizure.

• Heart Failure: Clinical syndrome with elevated natriuretic peptide levels and systemic/pulmonary congestion.