3.1 The ABCDE Systematic Assessment Approach in Irish Practice
Key Takeaways
- The ABCDE framework is the standardized, chronological algorithm endorsed by the HSE and NMBI for evaluating critically ill or deteriorating adult patients.
- Respiratory rate is the most sensitive early physiological indicator of clinical deterioration; tachypnoea (RR ≥ 25/min) frequently precedes respiratory or cardiac arrest.
- Target oxygen saturation is 94%–98% for most acute patients, but must be titrated to 88%–92% in patients at confirmed risk of hypercapnic respiratory failure using controlled delivery devices.
- Basic airway adjuncts must be matched to patient consciousness: oropharyngeal airways require an absent gag reflex, while nasopharyngeal airways are strictly contraindicated in suspected basilar skull fractures.
- Urine output below 0.5 mL/kg/hour in an adult is a primary clinical marker of inadequate systemic organ perfusion and early acute kidney injury.
2.1 The ABCDE Systematic Assessment Approach in Irish Practice
In acute healthcare settings throughout Ireland, the ABCDE (Airway, Breathing, Circulation, Disability, Exposure) framework serves as the gold-standard systematic assessment methodology. Endorsed by the Health Service Executive (HSE), the National Clinical Effectiveness Committee (NCEC), and the Nursing and Midwifery Board of Ireland (NMBI), this structured, hierarchical approach ensures that life-threatening physiological derangements are rapidly identified and managed in order of clinical priority.
[!IMPORTANT] The Golden Rule of ABCDE: Always treat immediate life threats before moving to the next step. If the patient deteriorates at any point, or after delivering an intervention (e.g., suctioning, oxygen administration, fluid bolus), recommence the assessment immediately from Airway (A).
1. Airway (A): Assessment and Immediate Management
Airway compromise is an immediate emergency. Hypoxia leads to irreversible cerebral cellular death within 4 to 6 minutes. The registered general nurse (RGN) must confirm patency within seconds of patient contact.
Clinical Evaluation of Airway Patency
- Verbal Response: If the patient speaks in clear, unlaboured, full sentences, the airway is patent, breathing is sufficient to support phonation, and brainstem perfusion is preserved.
- Abnormal Airway Sounds:
- Snoring: Indicates partial pharyngeal occlusion, typically caused by the tongue falling back against the posterior pharyngeal wall due to reduced consciousness (loss of pharyngeal muscle tone).
- Gurgling: Indicates liquid secretions, blood, vomitus, or pulmonary edema fluid pooling in the upper airway.
- Stridor: A high-pitched, harsh inspiratory sound signifying severe upper airway narrowing or laryngeal oedema (e.g., anaphylaxis, foreign body aspiration, severe epiglottitis).
- Wheezing: An expiratory musical sound indicating lower airway bronchospasm or mucosal oedema.
- Silent Airway: In a struggling patient with paradoxical chest movements ("see-saw" breathing) and no audible air entry, complete airway obstruction is present.
Basic Airway Interventions & Positioning
- Simple Manual Maneuvers:
- Head-Tilt / Chin-Lift: Used in non-trauma cases to lift the tongue away from the posterior pharynx.
- Jaw-Thrust: The mandatory maneuver if cervical spine trauma is suspected (e.g., fall from height, road traffic accident). This lifts the mandible forward without extending the neck.
- Suctioning: Under direct visualization using a rigid wide-bore Yankauer suction catheter. Limit suction passes to <10–15 seconds to prevent suction-induced hypoxia and vagal bradycardia.
Basic Airway Adjuncts: Sizing, Insertion & Contraindications
| Adjunct | Sizing Method | Insertion Technique | Clinical Precautions & Contraindications |
|---|---|---|---|
| Oropharyngeal Airway (OPA / Guedel) | Measure vertically from the center of the patient's incisors (or corner of the mouth) to the angle of the mandible. | Insert with the concave curve pointing upwards toward the hard palate; advance until junction of hard and soft palate is reached, then rotate 180° into the pharynx. | Contraindicated in conscious or semi-conscious patients with an intact gag reflex. May induce vomiting, aspiration, or laryngospasm. |
| Nasopharyngeal Airway (NPA) | Measure from the tip of the patient's nose to the tragus of the ear. Diameter should approximate the patient's little finger (Size 6–7 mm for adult females; 7–8 mm for adult males). | Lubricate with water-soluble gel. Insert bevel facing the nasal septum gently along the floor of the nasal cavity perpendicular to the face. | Tolerated in semi-conscious patients with an intact gag reflex. <br/>STRICTLY CONTRAINDICATED in suspected basilar skull fracture (risk of intracranial passage). |
[!CAUTION] Basilar Skull Fracture Warning: Look for clinical signs: periorbital ecchymosis ("raccoon eyes"), mastoid ecchymosis ("Battle's sign"), haemotympanum, or clear cerebrospinal fluid (CSF) rhinorrhoea/otorrhoea. Never insert an NPA or nasogastric tube if these signs are present.
2. Breathing (B): Ventilation, Gas Exchange, and Oxygen Therapy
Once airway patency is assured, assess the adequacy of ventilation and oxygenation.
Respiratory Rate: The Most Sensitive Vital Sign
According to NCEC National Clinical Guideline No. 1, the respiratory rate is the single most sensitive marker of acute physiological deterioration. Tachypnoea (respiratory rate ≥ 25 breaths/min) is frequently the earliest sign of impending respiratory failure, metabolic acidosis (Kussmaul breathing), sepsis, or cardiovascular collapse, often preceding arrest by 24 to 72 hours.
Step-by-Step Breathing Assessment
- Effort and Work of Breathing: Observe for tracheal tug, sternocleidomastoid contraction, intercostal and subcostal indrawing, and paradoxical abdominal movements.
- Depth and Pattern: Shallow rapid breathing indicates respiratory fatigue; deep rapid breathing indicates metabolic acidosis or severe pain; Cheyne-Stokes indicates severe heart failure or central neurological dysfunction.
- Symmetry: Inspect chest expansion. Unilateral reduced expansion suggests pneumothorax, massive pleural effusion, lobar collapse, or flail chest.
- Auscultation: Systematically listen to bilateral lung fields (anterior, lateral, posterior). Assess for vesicular breath sounds, bronchial breathing (consolidation), coarse crackles (pulmonary edema or pneumonia), or wheeze.
- Pulse Oximetry ($SpO_2$): Measure peripheral arterial oxygen saturation. Interpret cautiously in severe peripheral vasoconstriction, hypothermia, carbon monoxide poisoning, or nail polish.
Target Oxygen Saturations in Irish Practice
- Standard Acute Inpatients (No hypercapnic risk): Target $SpO_2$ is 94%–98%.
- Patients at Risk of Hypercapnic Respiratory Failure: Target $SpO_2$ is 88%–92%.
- At-risk groups: Severe Chronic Obstructive Pulmonary Disease (COPD), cystic fibrosis, severe chest wall deformities (kyphoscoliosis), neuromuscular disease, or morbid obesity hypoventilation.
- Mechanism: Uncontrolled high-flow oxygen blunts the hypoxic respiratory drive, increases ventilation-perfusion ($V/Q$) mismatch, and worsens hypercapnia through the Haldane effect, potentially inducing carbon dioxide narcosis, coma, and respiratory arrest.
Oxygen Delivery Devices
| Device | Flow Rate | Delivered $FiO_2$ | Primary Indications |
|---|---|---|---|
| Nasal Cannulae | 1–4 L/min | 24%–36% | Mild hypoxaemia in stable patients; comfortable, allows eating and talking. |
| Simple Face Mask | 5–10 L/min | 40%–60% | Moderate hypoxaemia. Flow rate must be ≥5 L/min to flush exhaled $CO_2$ and prevent rebreathing. |
| Venturi Mask | Specific fixed flow per valve (2–12 L/min) | 24%, 28%, 35%, 40%, 60% | Gold standard for COPD / hypercapnic risk. Colour-coded entrainment valves provide exact, fixed $FiO_2$ independent of patient ventilatory pattern. |
| Non-Rebreather Mask (NRM) | 12–15 L/min | 60%–90% | Critical emergencies: Severe hypoxaemia, shock, sepsis, trauma. Ensure the reservoir bag is fully pre-inflated before placing on the patient. |
3. Circulation (C): Hemodynamic Perfusion and Fluid Balance
Circulation assessment determines the adequacy of tissue and end-organ perfusion.
Step-by-Step Circulation Assessment
- Pulse and Heart Rate: Assess rate, rhythm (regular vs irregularly irregular), and volume. Compare central (carotid/femoral) with peripheral (radial) pulses. Weak, thready pulses indicate hypovolaemia or cardiogenic shock; bounding pulses suggest hyperdynamic septic shock.
- Blood Pressure: Manual auscultation remains the gold standard if automated oscillometric devices report extreme values. Narrow pulse pressure (<30 mmHg) indicates severe vasoconstriction or hypovolaemia.
- Capillary Refill Time (CRT): Apply firm pressure to the distal phalanx of a finger (or sternum) for 5 seconds; release and count the seconds until baseline colour returns.
- Normal CRT: < 2 seconds.
- Prolonged CRT (≥ 2 seconds): Reflects peripheral microcirculatory hypoperfusion, hypovolaemic shock, or peripheral vascular collapse.
- Peripheral Skin Assessment: Check peripheral temperature and colour. Cool, clammy, mottled, pale skin indicates sympathetic compensatory vasoconstriction in shock.
- Hydration and Fluid Balance: Inspect oral mucosa, assess skin turgor over the sternum, check for raised jugular venous pressure (JVP) at 45°, and evaluate sacral and pedal edema.
- Urinary Output Monitoring:
- Normal physiological threshold: > 0.5 mL/kg/hour for an adult.
- Oliguria (< 0.5 mL/kg/hour for 2 consecutive hours) is one of the earliest signs of acute renal hypoperfusion and impending Acute Kidney Injury (AKI).
- Example: For a 70 kg patient, minimum acceptable urine output is $70 \times 0.5 = 35\text{ mL/hour}$.
4. Disability (D): Neurological Function
A rapid assessment of central nervous system function identifies acute intracranial pathology, metabolic encephalopathy, and drug-induced depression.
The ACVPU Scale
In Irish practice under INEWS Version 2, the enhanced ACVPU scale is standard:
- A (Alert): Fully conscious, spontaneously tracks and responds appropriately.
- C (New Confusion): Acute disorientation, delirium, or altered mental status in a patient who was previously alert.
- V (Voice): Responds only to verbal stimulation.
- P (Pain): Responds only to central physical pressure (e.g., trapezius squeeze).
- U (Unresponsive): No motor or vocal response to painful stimuli.
Pupillary Reflexes
- Assess size (in millimeters), equality, and light reactivity (direct and consensual).
- Unilaterally dilated, unreactive ("blown") pupil points to ipsilateral oculomotor nerve (CN III) compression caused by uncal herniation from raised intracranial pressure (ICP).
- Bilateral pinpoint pupils suggest opioid toxicity or pontine haemorrhage.
Limb Motor Assessment
- Rapid bilateral motor check: assess hand-grip strength, arm drift (pronator drift), and leg movements. Asymmetrical weakness indicates an acute focal neurological deficit (e.g., stroke).
Capillary Blood Glucose (CBG)
- "Four is the floor": Blood glucose must be checked in every deteriorating patient or anyone with altered consciousness.
- Hypoglycaemia (< 4.0 mmol/L): Must be treated immediately to prevent irreversible neuronal damage. Administer 15–20 g rapid-acting carbohydrate orally if conscious, or 100 mL of 10% IV Glucose / 1 mg IM Glucagon if unconscious.
5. Exposure (E): Complete Examination and Thermal Integrity
Expose the patient to perform a thorough examination, while preserving privacy and maintaining normothermia.
Step-by-Step Exposure Assessment
- Skin Inspection: Carefully inspect all skin surfaces, including the back, axillae, groin, and perineum. Look for:
- Petechial or purpuric non-blanching rashes: Cardinal sign of meningococcal septicaemia or severe disseminated intravascular coagulation (DIC). Perform the "tumbler/glass test".
- Urticaria or angioedema: Suggests an acute anaphylactic reaction.
- Pressure Injury / Moisture Lesions: Check sacrum, heels, and greater trochanters.
- Surgical Sites, Lines, and Drains:
- Surgical wounds: erythema, dehiscence, purulent discharge, hematoma formation.
- Drains: volume, colour, patency, air leaks.
- Intravenous cannulae: check insertion sites for phlebitis using the Visual Infusion Phlebitis (VIP) score.
- Temperature Measurement:
- Record core temperature (tympanic or urinary sensor).
- Hypothermia (< 35.0°C): Impairs platelet function, disrupts coagulation cascades, and triggers lethal cardiac arrhythmias. Implement active warming (forced-air warming blankets, warmed IV fluids).
- Hyperpyrexia (> 38.0°C): Increases metabolic demand and oxygen consumption.
- Dignity and Thermal Comfort: Expose only one anatomical area at a time and recover promptly.
6. Clinical Pitfalls in ABCDE Practice
| Common Clinical Pitfall | Pathophysiological Consequence | Correct Irish Nursing Action |
|---|---|---|
| Relying solely on $SpO_2$ while ignoring a respiratory rate of 30/min. | A patient can maintain normal oxygen saturation (e.g., 97%) while in profound respiratory distress through compensatory hyperventilation, before crashing abruptly when respiratory muscles exhaust. | Recognize tachypnoea as an ominous red flag; calculate INEWS immediately and escalate for medical review. |
| Inserting a Nasopharyngeal Airway in head trauma with CSF leak. | The airway can pass through a fractured cribriform plate into the anterior cranial vault, causing intracranial infection or brain parenchymal trauma. | Strictly avoid NPA insertion in facial/cranial trauma. Use jaw-thrust and Guedel (if unconscious) or prepare for emergency endotracheal intubation. |
| Attributing acute confusion to baseline dementia without checking blood glucose. | Severe neuroglycopenia causes permanent cognitive disability or death within hours if untreated. | Mandate point-of-care capillary blood glucose checking (<4.0 mmol/L requires emergency treatment) in all patients with altered mental state. |
| Administering diuretics for oliguria without assessing volume status. | Giving loop diuretics to a patient with hypovolaemic shock precipitates severe intravascular depletion, circulatory collapse, and acute tubular necrosis. | Assess CRT, heart rate, blood pressure, and mucous membranes. Treat hypovolaemia with crystalloid fluid resuscitation, not diuretics. |
A 68-year-old male with a severe acute exacerbation of COPD and known chronic hypercapnia is admitted to the medical ward. On room air, his vital signs are: respiratory rate 26 breaths/min, SpO2 86%, heart rate 102 bpm, and blood pressure 138/84 mmHg. Which oxygen therapy regimen is most appropriate for this patient?
A 24-year-old polytrauma patient following a high-speed motor vehicle collision is brought into resuscitation. He is unconscious (GCS 6), has snoring respirations, visible blood and secretions in the mouth, bilateral periorbital ecchymosis ('raccoon eyes'), and clear fluid leaking from his right nostril. What is the priority nursing intervention for managing his airway?
A 72-year-old postoperative female weighing 70 kg has had an indwelling urinary catheter drain a total of 42 mL over the past 3 hours. Her current vital signs are: blood pressure 94/58 mmHg, heart rate 108 bpm, respiratory rate 20 breaths/min, and core temperature 37.1°C. How should the registered nurse interpret these clinical findings?