Respiratory Diagnostics & Procedures — Quick Reference
Arterial Blood Gases (ABG)
ABGs indicate how the lungs are functioning and guide treatments.
Key metrics: (oxygen content, blood pH, and carbon dioxide). Interventions are based on these values (ventilator vs nasal cannula).
Diagnostic and Monitoring Techniques
Bronchoscopy: visual examination of the bronchi; potential sampling.
Pulmonary Function Tests (PFTs): determine lung volumes and capacities; help distinguish disorders like COPD vs asthma.
Full PFTs (lab): performed in a body box; bedside spirometry for quick checks.
Polysomnography: sleep study for suspected sleep apnea; records breathing during sleep.
Auscultation: listening to lungs and heart with a stethoscope.
Imaging: CT and MRI used to visualize the lungs.
Adventitious Breath Sounds
Stridor: harsh, high-pitched sound from the upper airway; suggests obstruction or inflammation (e.g., croup, post-extubation).
Wheezes: continuous high-pitched whistling sounds from narrowed airways; common in asthma; can be heard on inspiration, expiration, or biphasic.
Rhonchi: gurgling sounds from secretions in the airways (bronchi); often improved with coughing; suction if needed.
Pleural rub: grating sound from inflamed or poorly lubricated pleural surfaces.
Medical and Surgical Procedures
Tracheostomy: creates an opening in the trachea for long-term airway protection or when intubation is not possible; may be temporary or permanent.
Speaking valve (PMV, Passy Muir Valve) enables phonation with a trach.
Thoracentesis (thoracocentesis): surgical puncture to remove pleural fluid and relieve pleural effusion.
Tube thoracostomy (chest tube): drains blood, fluid, or air in pneumothorax; connected to a drainage system and suction to re-expand the lung.
Takeaways
Understand diagnostic procedures used for respiratory disorders.
Recognize adventitious breath sounds and their clinical implications.
Know common medical and surgical interventions for respiratory conditions and their clinical context.
Arterial Blood Gases (ABG)
ABGs provide critical information about a patient's oxygenation, ventilation, and acid-base balance, indicating how the lungs are functioning and guiding treatments.
Key metrics include:
(Partial pressure of arterial oxygen): Measures the amount of oxygen dissolved in arterial blood. Normal range is typically . Values below this can indicate hypoxemia, which may necessitate oxygen therapy (e.g., nasal cannula) or mechanical ventilation.
(Partial pressure of arterial carbon dioxide): Measures the amount of carbon dioxide dissolved in arterial blood, reflecting the adequacy of ventilation. Normal range is typically . Elevated levels (hypercapnia) suggest hypoventilation, while decreased levels (hypocapnia) suggest hyperventilation.
: Measures the acidity or alkalinity of the blood. Normal range is typically . Values below indicate acidosis, and values above indicate alkalosis. The and bicarbonate () levels help differentiate between respiratory and metabolic causes of pH imbalance.
Interventions are based on these values, such as adjusting ventilator settings, initiating or discontinuing oxygen therapy, or administering medications to correct acid-base disturbances.
Diagnostic and Monitoring Techniques
Bronchoscopy: A procedure involving the insertion of a thin, lighted tube (bronchoscope) through the nose or mouth into the trachea and bronchi for direct visualization of the airway.
Indications: Diagnostic (e.g., biopsy for suspected tumors, culture for infection, removal of foreign bodies) or therapeutic (e.g., suctioning thick secretions, laser therapy for tumors).
Procedure: Patients are typically sedated. Local anesthesia may be applied to the throat.
Nursing considerations: NPO status before the procedure, monitoring vital signs and respiratory status during and after, assessing for gag reflex return post-procedure before allowing oral intake, and watching for complications (e.g., bleeding, pneumothorax, bronchospasm).
Pulmonary Function Tests (PFTs): A group of non-invasive tests that measure lung volumes, capacities, rates of flow, and gas exchange. They are essential for diagnosing and differentiating various respiratory disorders.
Full PFTs (lab): Conducted in a specialized lab within a body plethysmograph (body box) to measure static lung volumes, including:
Forced Vital Capacity (FVC): The total amount of air exhaled forcefully and rapidly after a maximal inspiration. Reduced in restrictive lung diseases.
Forced Expiratory Volume in 1 second (FEV1): The volume of air exhaled in the first second during the FVC maneuver. Reduced in obstructive lung diseases.
FEV1/FVC ratio: A key indicator to distinguish between obstructive (ratio < ) and restrictive (ratio normal or increased) lung diseases.
Total Lung Capacity (TLC): The total volume of air in the lungs after a maximal inspiration. Reduced in restrictive disorders.
Residual Volume (RV): The volume of air remaining in the lungs after a maximal exhalation. Increased in obstructive disorders.
Bedside spirometry: A simpler version often used for quick checks or monitoring, primarily measuring FVC and FEV1.
Polysomnography (Sleep Study): A comprehensive test used to diagnose sleep disorders, most commonly sleep apnea.
Procedure: Performed overnight in a sleep lab or at home. Sensors record multiple physiological parameters, including:
Electroencephalogram (EEG) for brain activity.
Electrooculogram (EOG) for eye movements.
Electromyogram (EMG) for muscle activity.
Electrocardiogram (ECG) for heart rate and rhythm.
Airflow through the nose and mouth.
Respiratory effort (chest and abdominal movement).
Oxygen saturation (SpO2) and carbon dioxide levels.
The data helps identify episodes of apnea (cessation of breathing) or hypopnea (shallow breathing) and their impact on oxygen levels and sleep architecture.
Auscultation: The act of listening to body sounds with a stethoscope, particularly the lungs and heart.
Normal breath sounds:
Vesicular: Soft, low-pitched sounds heard over most of the lung fields, longer on inspiration.
Bronchial: Loud, high-pitched, harsh sounds heard over the trachea; shorter on inspiration.
Bronchovesicular: Medium-pitched, moderatelty loud sounds heard between the scapulae and beside the sternum.
Imaging: Advanced imaging techniques used to visualize lung structures and identify abnormalities.
Computed Tomography (CT) scan: Provides detailed cross-sectional images of the lungs and surrounding structures, excellent for identifying pulmonary emboli, tumors, interstitial lung disease, and bronchiectasis.
Magnetic Resonance Imaging (MRI): Offers high-resolution images, particularly useful for soft tissue differentiation, evaluating mediastinal structures, and some vascular issues, though less commonly used for primary lung parenchyma assessment compared to CT.
Adventitious Breath Sounds
Stridor: A harsh, high-pitched, musical sound typically heard on inspiration, but can be biphasic if severe. It originates from turbulent airflow through a narrowed upper airway (larynx or trachea).
Clinical implication: Critical sign of impending airway obstruction, often indicating conditions like croup, epiglottitis, foreign body aspiration, severe laryngeal edema (e.g., post-extubation), or tracheal stenosis. Requires immediate assessment and intervention.
Wheezes: Continuous, high-pitched, squeaking or whistling sounds, typically louder on expiration but can be heard on inspiration or biphasic. Caused by air attempting to pass through narrowed or obstructed lower airways (bronchioles and bronchi).
Clinical implication: Characteristic of asthma, COPD, bronchitis, or foreign body obstruction. Worsening wheezing or a sudden absence of wheezing (silent chest) can indicate severe bronchospasm and critically compromised airflow.
Rhonchi: Low-pitched, gurgling, rumbling, or snoring sounds, often continuous and heard primarily on expiration. Produced by air passing through larger airways partially obstructed by thick secretions, mucus, or fluid.
Clinical implication: Commonly heard in conditions like bronchitis, pneumonia, or cystic fibrosis. Often clears or changes significantly after coughing or suctioning, which helps differentiate them from wheezes.
Crackles (Rales): Brief, discontinuous, popping, or crackling sounds, like hair rubbing together or velcro opening. They are classified as fine (high-pitched, short) or coarse (low-pitched, longer).
Clinical implication: Generated by the sudden opening of collapsed small airways or by air bubbling through fluid in the alveoli. Causes include pneumonia, heart failure (pulmonary edema), atelectasis, and pulmonary fibrosis.
Pleural rub: A grating, creaking, or squeaky sound, synchronous with respiration, best heard at the end of inspiration and beginning of expiration. It sounds like two pieces of leather rubbing together.
Clinical implication: Occurs when inflamed or poorly lubricated pleural surfaces (visceral and parietal pleura) rub against each other during breathing. Indicates pleurisy, pleural effusion (early stages before fluid separation), or pneumonia.
Medical and Surgical Procedures
Tracheostomy: A surgical procedure that creates a direct opening (stoma) into the trachea through the neck, bypassing the upper airway.
Indications:
Long-term airway protection: For patients requiring prolonged mechanical ventilation (e.g., spinal cord injury, comatose patients).
Upper airway obstruction: Due to tumors, trauma, or severe edema.
Inability to manage secretions: When a patient cannot effectively clear their own airway.
Ventilator weaning: Facilitates easier weaning from mechanical ventilation compared to prolonged endotracheal intubation.
Types:
Cuffed trach: Has an inflatable cuff that seals the airway, primarily used for mechanical ventilation to prevent air leakage and aspiration.
Uncuffed trach: Used in patients who do not require mechanical ventilation and are at low risk of aspiration, allowing for easier speaking and breathing.
PMV (Passy Muir Valve) or Speaking valve: A one-way valve that allows air to enter through the tracheostomy tube but diverts exhaled air past the vocal cords and out through the upper airway, enabling phonation. Proper cuff deflation is crucial before PMV placement.
Nursing considerations: Meticulous stoma care to prevent infection, regular suctioning, monitoring for complications like hemorrhage, dislodgement, or pneumothorax.
Thoracentesis (thoracocentesis): A procedure involving the surgical puncture of the chest wall into the pleural space with a needle to remove pleural fluid.
Indications:
Diagnostic: To analyze pleural fluid for infection, malignant cells, protein content, or other causes of pleural effusion.
Therapeutic: To relieve symptoms (e.g., dyspnea) caused by a large pleural effusion by removing fluid.
Procedure: Performed under local anesthesia, typically with ultrasound guidance. The patient is usually seated upright.
Nursing considerations: Informed consent, positioning, monitoring vital signs, assessing for pain, and observing for complications such as pneumothorax, bleeding, or infection post-procedure.
Tube thoracostomy (Chest Tube Insertion): The insertion of a hollow, flexible tube into the pleural space to drain air, fluid (e.g., blood, pus), or both.
Indications:
Pneumothorax: Air in the pleural space, causing lung collapse.
Hemothorax: Blood in the pleural space.
Pleural effusion: Excess fluid in the pleural space (e.g., malignant, empyema).
Chylothorax: Lymphatic fluid in the pleural space.
Drainage system: Connected to a sealed drainage system with three main chambers:
Collection chamber: Gathers fluid or blood from the pleural space.
Water seal chamber: Acts as a one-way valve, allowing air to escape from the pleural space but preventing atmospheric air from entering the lung. Intermittent bubbling indicates air leak from the lung, while bubbling cessation indicates resolution or obstruction. Tidaling (fluctuation of water level with respiration) is expected and indicates patency.
Suction control chamber: Regulates the amount of suction applied to the pleural space, either water-based (usually ) or dry suction.
Nursing care: Maintaining a closed system, monitoring drainage amount and characteristics, ensuring tube patency, assessing respiratory status and pain, keeping the drainage system below chest level, changing dressings, and knowing emergency procedures (e.g., taping all four sides of a sterile dressing if the tube dislodges).
Takeaways
Develop a thorough understanding of diagnostic procedures used for respiratory disorders, including their indications and patient care considerations.
Enhance the ability to recognize and interpret adventitious breath sounds, understanding their clinical implications and potential underlying pathologies.
Acquire detailed knowledge of common medical and surgical interventions for respiratory conditions, including their purpose, types, and crucial nursing management.