Free NGN Case Study: Chest Tube Prioritization — Full Walkthrough

The NGN case study is the hardest part of the new NCLEX. One unfolding scenario, six interconnected questions, and partial credit scoring that rewards clinical judgment over rote memory.

Here's a real case study walkthrough — the kind you get for free on ClarityNCLEX every day.

The Scenario

You are the nurse on a medical-surgical unit. At 07:00, you receive report on four patients. At 07:15, the charge nurse asks you to prioritize rounds based on the following situations.

**Patient A:** 58-year-old male, post-op day 1 thoracotomy with chest tube to water seal. The previous nurse reports the drainage chamber has 100 mL of serosanguinous fluid over the past 8 hours. No air leak noted. Vital signs: BP 138/76, HR 82, RR 16, SpO2 97% on room air.

**Patient B:** 72-year-old female admitted with pneumonia. IV antibiotics running at 50 mL/hr. Reports productive cough with green sputum. Vital signs: BP 142/84, HR 94, RR 20, SpO2 94% on 2L nasal cannula.

**Patient C:** 45-year-old male admitted for dehydration. Receiving IV fluids at 150 mL/hr. Reports feeling "much better." Vital signs: BP 110/68, HR 74, RR 14, SpO2 99% on room air.

**Patient D:** 66-year-old female awaiting placement at a long-term care facility. History of CHF. Vital signs: BP 128/72, HR 70, RR 16, SpO2 97% on room air.

Understanding NGN Scoring

NGN case studies use partial credit scoring. Each question is scored independently, and some have multiple correct selections (SATA-style).

The test isn't testing your ability to memorize. It's testing your ability to prioritize under realistic time pressure.

Question 1: First Patient to Assess

**Correct Answer: Patient A — the chest tube patient.**

Rationale:

• Post-op day 1 thoracotomy is the highest-acuity patient
• The chest tube was placed for re-expansion of the lung — any dislodgement or malfunction is immediately life-threatening
• While Patient B has pneumonia, the vital signs are stable
• Patients C and D are stable or improving

NCLEX principle: When in doubt, prioritize the post-op patient with an invasive device. Chest tubes, central lines, and surgical drains all carry immediate risk.

Question 2: Chest Tube Assessment

You assess Patient A. The chest tube dressing is intact with no leaks. The drainage system shows 100 mL serosanguinous fluid over 8 hours. Which findings require immediate intervention?

A. Drainage of 100 mL over 8 hours

B. Continuous bubbling in the water seal chamber

C. Gentle fluctuation (tidaling) in the water seal chamber

D. Subcutaneous emphysema around the insertion site

E. Patient reports pain at 4/10 on movement

Rationale:

• B: Continuous bubbling in the water seal chamber indicates an air leak — could be a disconnection or leak from the lung
• D: Subcutaneous emphysema (crepitus under the skin) can indicate the tube has partially pulled out
• A: 100 mL over 8 hours is within expected range for post-op day 1
• C: Tidaling (fluctuation with respiration) is normal — it means the system is patent
• E: 4/10 pain on movement is expected post-thoracotomy

Question 3: Immediate Action

The water seal chamber shows continuous bubbling. What is your priority action?

A. Replace the drainage system

B. Notify the surgeon immediately

C. Check all connections and tape them securely

D. Increase suction pressure

Rationale: The most common cause of continuous bubbling is a loose connection. Before escalating, trace the tubing from patient to drainage unit, check each connection, and reinforce with tape. If bubbling continues after taping, then notify the surgeon.

The Clinical Judgment Model

This case study tests all four layers of the NCSBN Clinical Judgment Model:

Why This Matters

The NGN isn't a knowledge test. It's a judgment test. Two students can know the same facts, but the one who recognizes subtle decompensation faster scores higher on the case study.

That clinical judgment is exactly what ClarityNCLEX builds with daily NGN case studies — free, every day, with full rationales.

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