9–15% of the exam. This category is about seeing trouble coming — knowing normal lab values, preparing clients for diagnostic tests, and recognizing the early signs of a complication before it becomes an emergency.
Lab values as red flags
You aren’t memorizing numbers for their own sake — you’re learning which results demand action. Anchor on the values that change what you do next: a potassium of 6.8 means hold potassium-raising drugs and get an ECG; a platelet count under 50,000 means bleeding precautions; an INR of 5 on warfarin means hold the dose and expect vitamin K.
The complete, exam-focused table is on the lab values page — study it until the ranges are automatic.
Before and after procedures
Diagnostic-test questions usually hinge on preparation and post-care. General rules:
- Consent and allergies — confirm both; ask specifically about iodine/shellfish before contrast studies and check renal function (creatinine) first.
- NPO status — many scopes and contrast studies require it; verify how long.
- After a scope or biopsy — monitor vitals, watch for bleeding, and for anything entering the airway (bronchoscopy) confirm the gag reflex returns before food or drink.
- Post-angiography/cardiac cath — keep the extremity straight, monitor the site for bleeding, and check distal pulses.
Early complication signs
- Post-op hemorrhage — rising pulse and falling BP before obvious bleeding; check under the client and dressings.
- Pulmonary embolism — sudden dyspnea, pleuritic chest pain, tachycardia, anxiety; a known risk after immobility or surgery.
- Infection — rising temperature, tachycardia, and rising WBC; in older adults, new confusion may be the first sign.
- Compartment syndrome — pain out of proportion, especially with passive stretch, under a cast. An emergency.
Trend, don’t snapshot. NGN “trend” items give you vitals or labs over time. A single value can be normal while the direction screams deterioration — read the change, not just the latest number.
Lines, tubes, and drains
- Central lines — sterile technique; for air-embolism risk, position and clamping matter.
- Chest tubes — keep the system below the chest, watch for tidaling; continuous bubbling in the water seal signals an air leak.
- NG tubes — confirm placement (pH, X-ray) before use; keep the head of bed elevated to prevent aspiration.
Practice it: reinforce this category with explained questions in the question bank, and see how much of your exam it fills on the test plan page.
