NLE Respiratory Nursing — Respiratory Assessment & DiagnosticsSummary

The foundation of respiratory nursing is the classic four-step physical assessment performed side-to-side for comparison. Inspection evaluates rate (normal 12–20 breaths/min), rhythm, depth, and effort, noting red flags such as accessory muscle use, nasal flaring, retractions, pursed-lip breathing, and tripod positioning—all indicators of increased work of breathing (WOB). Cyanosis (blue lips/tongue) is a LATE sign requiring approximately 5 g/dL deoxygenated haemoglobin and indicates severe hypoxaemia. Clubbing (bulbous finger-tips) signals chronic hypoxia, while barrel chest (increased anteroposterior diameter) reflects chronic air trapping in COPD/emphysema. Palpation assesses tactile fremitus (vibration when patient says 'ninety-nine'), which INCREASES over consolidation (pneumonia) and DECREASES over pleural effusion, pneumothorax, or air trapping. Percussion yields resonance (normal lung), dullness (fluid/consolidation), or hyperresonance (trapped air). Auscultation identifies normal breath sounds (vesicular, bronchovesicular, bronchial) and adventitious sounds critical to diagnosis.

Crackles (formerly called rales) are discontinuous, popping sounds from fluid-filled or collapsed alveoli reopening; they indicate pneumonia, pulmonary oedema, and acute decompensated heart failure. Wheezes are continuous, musical, high-pitched sounds from narrowed airways—classic findings in asthma (often expiratory) and COPD. Rhonchi are low-pitched, snoring-quality sounds from secretions in large airways and may clear with coughing. Stridor is a high-pitched, crowing sound heard WITHOUT a stethoscope, indicating upper-airway obstruction (epiglottitis, croup, foreign body)—this is a respiratory EMERGENCY requiring immediate intervention and preparation of airway equipment. Pleural friction rub is a grating sound from inflamed pleura, seen in pleurisy. Each sound carries specific diagnostic weight and directs nursing interventions.

ABGs measure oxygenation (PaO2, SaO2), ventilation (PaCO2), and acid–base balance (pH, HCO3). Normal values are: pH 7.35–7.45, PaCO2 35–45 mmHg, HCO3 22–26 mEq/L, PaO2 80–100 mmHg, SaO2 95–100%. The ROME mnemonic guides systematic interpretation: (1) Assess pH—<7.35 = acidosis, >7.45 = alkalosis. (2) Identify the PRIMARY problem using 'Respiratory Opposite' (pH and PaCO2 move opposite: high CO2 with low pH = respiratory acidosis) and 'Metabolic Equal' (pH and HCO3 move together: low HCO3 with low pH = metabolic acidosis). (3) Check compensation—has the non-primary system shifted to normalise pH? Full compensation returns pH to normal; partial compensation moves pH toward normal; uncompensated leaves pH abnormal. Example: pH 7.30, PaCO2 50, HCO3 24 = respiratory acidosis (uncompensated, as in COPD hypoventilation). Example: pH 7.50, PaCO2 30, HCO3 24 = respiratory alkalosis (hyperventilation, anxiety, early sepsis). Example: pH 7.30, PaCO2 40, HCO3 16 = metabolic acidosis (DKA, diarrhoea, shock).

Pulse oximetry provides non-invasive, continuous monitoring of oxygen saturation; normal is 95–100%. However, SpO2 reflects oxygenation (saturation) ONLY, NOT ventilation. A patient can have normal SpO2 while retaining CO2 and developing respiratory acidosis—always confirm with ABG when respiratory status is unclear. Pulse oximetry readings are unreliable with poor perfusion (shock, vasoconstriction), hypothermia, motion, nail polish, dark skin pigmentation (may underestimate), and crucially, carbon monoxide poisoning (which falsely elevates SpO2 because CO binds haemoglobin and reads as 'saturation'). In pulse oximetry, SpO2 of 92% corresponds roughly to a PaO2 of 60 mmHg on the oxygen–haemoglobin dissociation curve; below this point the curve becomes steep and small changes in SpO2 reflect large drops in PaO2. Use SpO2 as a screening and trending tool, not as a definitive measure of gas exchange.

PFTs classify lung pathology into obstructive and restrictive patterns. Key values are FEV1 (forced expiratory volume in 1 second), FVC (forced vital capacity), and the FEV1/FVC ratio. In OBSTRUCTIVE disease (asthma, COPD, bronchiectasis), airflow out of the lungs is limited; the FEV1 drops more than FVC, resulting in a REDUCED FEV1/FVC ratio (<70%). Asthma obstruction is REVERSIBLE after bronchodilators; COPD obstruction is only PARTIALLY reversible. In RESTRICTIVE disease (pulmonary fibrosis, chest-wall deformity, obesity, pneumonectomy), lung volumes shrink; FVC is REDUCED but the FEV1/FVC ratio is NORMAL or INCREASED because the small volume is expelled quickly. Peak expiratory flow rate (PEFR) is a simple home-monitoring tool used in asthma; patients record their personal best and respond to traffic-light zones: green (≥80% of best) = good control, yellow (50–79%) = caution/use reliever inhaler, red (<50%) = emergency.

The chest X-ray (CXR) is the most frequently ordered thoracic imaging test. Nursing responsibilities include removing metal objects and jewellery, confirming no pregnancy (or arranging shielding), and explaining the procedure—no fasting or special prep is required. The X-ray is done in multiple views (PA, lateral, apical-lordotic) to detect pathology. Common findings by condition: pneumonia shows infiltrates/consolidation (white density); COPD/emphysema show hyperinflation with flattened diaphragms; pneumothorax shows a collapsed lung with visible pleural line and possible mediastinal shift (in tension, this is an emergency); pleural effusion blunts the costophrenic angles (fluid obscures the normal sharp angle); heart failure shows pulmonary oedema with bilateral infiltrates and a widened cardiac silhouette. Routine uses include confirming endotracheal tube (ETT) placement (tip should be 2–3 cm above the carina) and central line position. After the X-ray, review results with the team and communicate abnormal findings to the physician promptly.

Oxygen is a medication and requires a physician/advanced practice order. Low-flow systems deliver oxygen MIXED with ambient air, so FiO2 varies with the patient's breathing pattern and minute ventilation. NASAL CANNULA delivers ~24–44% O2 at 1–6 L/min; it is comfortable, allows eating and talking, and is first-line for stable patients. Flows >6 L/min do NOT increase FiO2 meaningfully and cause mucosal drying—add humidification above 4 L/min. SIMPLE FACE MASK delivers ~40–60% O2 at 5–10 L/min; a MINIMUM of 5 L/min is required to flush exhaled CO2 from the mask (without this, CO2 rebreathing occurs). PARTIAL REBREATHER MASK (mask + non-vented reservoir bag) delivers ~60–80% O2 at 6–11 L/min; keep the bag from fully collapsing during inspiration. NON-REBREATHER MASK (highest low-flow delivery) provides ~80–95% O2 at 10–15 L/min using a reservoir bag with one-way valves; this is the device of choice for severe hypoxaemia and emergencies (shock, severe pneumonia). Ensure the bag stays at least 1/3 full during inspiration. The VENTURI MASK is a HIGH-FLOW, FIXED-PERFORMANCE system delivering precise FiO2 (typically 24%, 28%, 31%, 35%, 40%) REGARDLESS of breathing pattern. This is the DEVICE OF CHOICE FOR COPD because it allows controlled, low-concentration oxygen delivery.

In advanced COPD, chronic hypercapnia (elevated CO2) desensitises the respiratory centre to CO2 as a breathing stimulus. Instead, these patients rely on a HYPOXIC DRIVE—their respiratory drive is triggered by low PaO2, not high CO2. If you give these patients unrestricted, high-concentration oxygen (titrating to the 'normal' 94–98% SpO2 target), their PaO2 rises, the hypoxic drive disappears, and they stop breathing effectively. The result is worsening hypoventilation, CO2 retention, and possibly respiratory failure. Therefore, in COPD, titrate oxygen to a TARGET SpO2 OF 88–92% only, using the lowest FiO2 needed (often nasal cannula at 1–2 L/min or Venturi mask at 24–28% FiO2). Monitor closely with ABG; watch for signs of CO2 narcosis (drowsiness, headache, confusion, asterixis). NEVER withhold oxygen from a hypoxic COPD patient, but titrate carefully and recheck SpO2 and ABG 15–30 minutes after any change. This nuanced approach prevents both hypoxaemia (which causes tissue damage and organ failure) and CO2 narcosis (which impairs consciousness and protective reflexes).

Oxygen is a gas under pressure and is FLAMMABLE. Establish fire safety: NO SMOKING / NO OPEN FLAME near oxygen therapy; post 'oxygen in use' signage conspicuously; secure oxygen cylinders upright in wall mounts to prevent falling and rupture. Keep cylinders away from heat sources. During oxygen administration, humidification becomes important at flows >4 L/min because dry oxygen causes mucosal irritation, epistaxis (nosebleeds), and inflammatory responses that worsen gas exchange. Use bubble humidifiers for nasal cannula and face masks, or heated humidifiers for non-rebreather masks at high flows. Monitor for skin breakdown behind the ears (from mask pressure) and over the bridge of the nose; reposition and pad masks to prevent breakdown. Encourage oral hygiene and lip moisturising. In long-term oxygen therapy (LTOT), educate patients on safe home storage, cylinder handling, and avoiding trips/falls from tubing.

A chest tube evacuates air (pneumothorax), fluid (pleural effusion), blood (haemothorax), or pus (empyema) from the pleural space to re-expand the lung and restore negative intrapleural pressure. The traditional three-chamber system consists of: (1) COLLECTION CHAMBER—collects all drainage; mark the level externally with a time/date marker to monitor amount, colour (clear/serosanguineous/purulent), and rate (continuous vs intermittent). (2) WATER-SEAL CHAMBER—acts as a one-way valve allowing air to exit the pleural space but preventing backflow of air. TIDALING (gentle fluctuation of fluid with respiration) is NORMAL and expected—it indicates communication between the pleural space and the system. (3) SUCTION-CONTROL CHAMBER—regulates the amount of suction applied (determined by water level in wet systems, or a dial in dry systems). The nurse must keep the entire system BELOW chest level at all times to prevent backflow of fluid into the chest. Never clamp the tube routinely unless specifically ordered. Do not milk or strip the tube unless ordered, as this can generate high pressures within the pleural space.

Sudden loss of tidaling may indicate LUNG RE-EXPANSION (positive finding—the lung has fully expanded and is no longer compressing the pleural space) OR obstruction (kink, clog)—assess the patient and tubing to differentiate. Intermittent bubbling in the water-seal chamber is NORMAL during early air evacuation (as in pneumothorax) or with patient coughing and expiration. However, CONTINUOUS BUBBLING IN THE WATER-SEAL CHAMBER indicates an AIR LEAK—either in the patient's lung/at the chest-wall insertion site, or in the tubing/system connections. To locate the leak: (1) Check all connections and tighten if loose. (2) Briefly and gently clamp the tube near the chest wall; if bubbling stops, the leak is in the patient/insertion site; if it continues, the leak is downstream in tubing/system. Place the unit in a sterile water bath if needed. Report the finding to the physician. If the CHEST TUBE PULLS OUT of the chest, immediately cover the site with a sterile occlusive dressing TAPED ON THREE SIDES (creates a flutter-valve allowing air out but not in); taping all four sides traps air and risks tension pneumotharax. Notify the physician immediately. If the tube DISCONNECTS from the drainage system, submerge the tube end in sterile water or saline to re-establish a seal, then obtain a new sterile system. Keep sterile water and clamps at the bedside for emergencies.

Tension pneumotharax is a MEDICAL EMERGENCY. It occurs when air accumulates in the pleural space faster than it can exit, building positive pressure that compresses the lung, shifts the mediastinum, and compromises venous return and cardiac output. Classic signs are: sudden severe dyspnoea, tachycardia, hypotension, tracheal deviation (away from the affected side), absent breath sounds on the affected side, and distended neck veins (JVD). The patient may deteriorate to shock and cardiovascular collapse within minutes. Immediate actions: (1) Elevate the patient's head to 45 degrees if tolerate; (2) Apply high-flow oxygen (non-rebreather mask, 15 L/min); (3) Prepare emergency equipment—suction, bag-valve-mask, intubation tray; (4) Notify the physician/team STAT. (5) Needle decompression (large-bore needle to the 2nd intercostal space, midclavicular line) may be performed by a physician as a temporary bridge to chest-tube insertion. (6) Have the physician insert a chest tube. Never clamp the tube once inserted; keep it patent and monitor drainage. The NLE often presents scenario questions where a student must recognise tension pneumotharax and distinguish it from simple pneumotharax or other emergencies.

Respiratory patients present with multiple NANDA nursing diagnoses, prioritised using Maslow's hierarchy. At the physiologic base: INEFFECTIVE AIRWAY CLEARANCE (related to excess secretions, inflammation, obstruction; evidenced by adventitious sounds, dyspnoea, cyanosis)—interventions include positioning, suctioning, deep breathing/coughing. IMPAIRED GAS EXCHANGE (related to ventilation/perfusion mismatch, alveolar hypoventilation; evidenced by low SpO2, tachycardia, restlessness)—monitor ABG, titrate oxygen, promote breathing exercises. INEFFECTIVE BREATHING PATTERN (related to pain, anxiety, muscle fatigue; evidenced by rapid/shallow breathing, use of accessory muscles)—manage pain, teach breathing techniques, reduce anxiety. At safety level: RISK FOR ASPIRATION (especially in post-operative/sedated patients); RISK FOR INFECTION (chest-tube site, ventilator-associated); RISK FOR FALLS (from oxygen-related tubing, CNS effects of hypoxia/CO2 narcosis). Psychosocial level: ANXIETY (from dyspnoea, fear of suffocation); DEFICIENT KNOWLEDGE (about disease, oxygen use, activity restrictions). Interventions are evidence-based and individualised; nursing-sensitive outcomes are monitored (SpO2, ABG values, respiratory rate, breath-sound clarity, ability to expectorate, patient/family knowledge). Documentation is thorough and timely, supporting continuity of care under RA 9173 standards.