A mixed acid-base disorder exists when two or more primary disturbances occur simultaneously — not a single disorder with compensation. Compensation never fully corrects pH and never overshoots; when pH is further from normal than expected for a single disorder, a mixed pattern is present. Missing a mixed disorder means treating one component while the other worsens, risking fatal pH extremes. Top 3 nursing priorities: 1. Obtain ABG + electrolytes simultaneously and apply stepwise analysis before calling the physician 2. Identify life-threatening pH (<7.20 or >7.60) requiring urgent intervention 3. Treat the underlying causes of BOTH disorders concurrently Common NCLEX trap: Assuming a normal pH means no acid-base problem — a patient with concurrent metabolic acidosis AND metabolic alkalosis can have a pH of 7.40 with dramatically abnormal bicarbonate and anion gap. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or role, reread that line; scope errors are classic trap answers even when the clinical topic is familiar. Run a 60-second scan: breathing work and oxygenation,...