A client's ABG results are: pH 7.28, PaCO₂ 58 mmHg, HCO₃ 26 mEq/L, PaO₂ 68 mmHg. How does the nurse interpret this?

ABG INTERPRETATION uses a systematic four-step approach: STEP 1 — pH: 7.28 is BELOW 7.35 → ACIDOSIS; STEP 2 — Identify the cause: PaCO₂ 58 mmHg is ABOVE 45 mmHg → RESPIRATORY cause (CO₂ is an acid; elevated CO₂ causes acidosis); STEP 3 — Check compensation: HCO₃ 26 mEq/L is within normal range (22-26) → NOT COMPENSATED (kidneys haven't retained bicarb yet); STEP 4 — Oxygenation: PaO₂ 68 mmHg is BELOW 80 mmHg → MILD HYPOXAEMIA. INTERPRETATION: Uncompensated Respiratory Acidosis with mild hypoxaemia. COMMON CAUSES of respiratory acidosis: COPD exacerbation; opioid-induced respiratory depression; neuromuscular disease (Guillain-Barré, myasthenia gravis); severe pneumonia; atelectasis. NURSING PRIORITIES: Assess airway and breathing immediately; prepare for possible intubation and mechanical ventilation if severe; administer supplemental oxygen; for COPD patients, target SpO₂ 88-92% (avoid hypoxic drive suppression); if opioid-induced: naloxone; stimulate patient to breathe, reposition; treat underlying cause. THE ROME MNEMONIC: Respiratory Opposite (pH and CO₂ move in opposite directions); Metabolic Equal (pH and HCO₃ move in the same direction).