Case studyClinical reasoning

Four Principles of Clinical Reasoning Discussion

The framework asks you to trend data, not list it. A BMI of 17.6 in a 45-year-old man is the finding most students record and never interpret.

Editorial process

Last reviewed · August 23, 2026

Written by

Maren Caldwell

MSN, RN, CNE

Medical-surgical nursing, pharmacology and NCLEX preparation

Reviewed by

Dr. Tessa Redmond

DNP, RN, CNE

Evidence-based practice and clinical education

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Interpret the task
Assignment instructions
Deliverables
Proposed outline
Research plan
Reference shortlist
Final review

Trending is the step students skip

The second principle is the one that distinguishes a good submission. Identifying relevant data is recognition and most students manage it; trending means asking what direction each value is moving and what it implies about whether this patient is compensating or failing. A pulse of 110 with a respiratory rate of 20 after three days of vomiting is not an isolated abnormal number, it is early compensation for volume loss, and the significance of a normal blood pressure alongside it is that compensation is still working, which is exactly the situation that deteriorates without warning. The temperature of 100.5 adds an inflammatory or infective process to a picture that vomiting alone would not explain. None of that is visible in an isolated reading, which is why the principle is called trending rather than measuring, and why a table of values with no direction attached scores badly. Compensation is a warning.

The body mass index is the finding most often recorded and least often interpreted. A six-foot man weighing 150 pounds is underweight, and combined with a month of poor appetite and fatigue this is chronic rather than acute, which reframes the presentation: something has been happening for weeks and the three days of vomiting is the acute exacerbation on top of it. The drinking history is the thread that ties it together, and note how it is phrased, since denying intake in the past week while admitting weekend binges is a pattern, not an absence. That makes alcohol-related pathology the essence of this situation: pancreatitis, alcoholic hepatitis, gastritis, and withdrawal as a complication of a week without drinking. Let your nursing priority follow from that rather than from the pain, because volume status, electrolyte derangement and withdrawal risk all outrank analgesia in the first hour.

Likely learning objectives

Trend clinical data rather than listing abnormal values.
Read compensated vital signs as a warning rather than reassurance.
Interpret body mass index as evidence of a chronic process.
Derive nursing priority from the essence of the situation rather than from the complaint.

Assignment instructions

Read the full question

Review every instruction before using the planning guidance that follows.

1. Identify and interpret RELEVANT clinical data. 2. TREND relevant clinical data to determine current status (stable vs. unstable). 3. Grasp the “essence” of the current clinical situation. 4. Determine nursing PRIORITY and plan of care. History of Present Problem: John Richards is a 45-year-old male who presents to the emergency department (ED) with abdominal pain and worsening nausea and vomiting the past three days that have not resolved. He is feeling more fatigued and has had a poor appetite the past month. He denies any ETOH (alcohol) intake the past week, but admits to episodic binge drinking on most weekends. John weighs 150 pounds (68.2 kg) and is 6’0″ (BMI 17.6). You are the nurse responsible for his care. What data from the PRESENT PROBLEM are RELEVANT and must be interpreted as clinically significant by the nurse? RELEVANT Data from Present Problem: Clinical Significance: Patient Care Begins: Orthostatic BP’s: What VS data are RELEVANT and must be recognized as clinically significant by the nurse? RELEVANT VS Data: Rationale: Current VS: P-Q-R-S-T Pain Assessment (5th VS): T: 100.5 F/38.1 C (oral) Provoking/Palliative: Nothing/nothing P: 110 (regular) Quality: Ache R: 20 Region/Radiation: RUQ/epigastric BP: 128/88 Severity: 6/10 O2 sat: 95% RA Timing: Continuous Position: HR: BP: Lying 110 128/8 Standing 132 124/80 © 2016 Keith Rischer/www.KeithRN.com What assessment data are RELEVANT and must be recognized as clinically significant by the nurse? RELEVANT Assessment Data: Rationale: Lab Results: What lab results are RELEVANT and must be recognized as clinically significant by the nurse? RELEVANT Lab(s): Clinical Significance: TREND: Improve/Worsening/Stable: Current Assessment: GENERAL APPEARANCE: Appears uncomfortable, body tense, occasional facial grimacing RESP: Breath sounds clear with equal aeration bilaterally, non-labored respiratory effort CARDIAC: Pink, warm & dry,1+ pitting edema lower extremities, heart sounds regular–S1S2, pulses strong, equal with palpation at radial/pedal/post-tibial landmarks NEURO: Alert & oriented to person, place, time, and situation (x4) GI: Abdomen distended, large–rounded–firm to touch, bowel sounds audible per auscultation in all 4 quadrants GU: Voiding without difficulty, urine clear/light orange, loss of pubic hair SKIN: Skin integrity intact, color normal for patient, sclera of eyes light yellow in color, lips and oral mucosa tacky dry, softball-sized ecchymosis on abdomen Complete Blood Count (CBC:) Current: High/Low/WNL? Previous: WBC (4.5–11.0 mm 3) 12.8 9.5 Hgb (12–16 g/dL) 10.2 11.2 Platelets (150-450 x103/µl) 98 122 Neutrophil % (42–72) 88 75 Band forms (3–5%) 3 0 Basic Metabolic Panel (BMP:) Current: High/Low/WNL? Previous: Sodium (135–145 mEq/L) 135 138 Potassium (3.5–5.0 mEq/L) 3.5 3.8 Glucose (70–110 mg/dL) 78 88 BUN (7–25 mg/dl) 38 25 Creatinine (0.6–1.2 mg/dL) 1.5 1.1 © 2016 Keith Rischer/www.KeithRN.com What lab results are RELEVANT and must be recognized as clinically significant by the nurse? RELEVANT Lab(s): Clinical Significance: TREND: Improve/Worsening/Stable: RELEVANT Lab(s): Clinical Significance: TREND: Improve/Worsening/Stable: What lab results are RELEVANT and must be recognized as clinically significant by the nurse? RELEVANT Lab(s): Clinical Significance: TREND: Improve/Worsening/Stable: Put it All Together to THINK Like a Nurse! 1. What is the primary problem that your patient is most likely presenting? Four Principles of Clinical Reasoning Discussion 2. What nursing priority(ies) will guide your plan of care? (if more than one-list in order of PRIORITY) Coags: Current: High/Low/WNL? Previous: PT/INR (0.9–1.1 nmol/L) 1.5 1.2 Liver Function Test (LFT:) Current: High/Low/WNL? Previous: Albumin (3.5–5.5 g/dL) 2.5 2.9 Total Bilirubin (0.1–1.0 mg/dL) 4.2 2.2 Alkaline Phosphatase male: 38–126 U/l female: 70–230 U/l 285 155 ALT (8–20 U/L) 128 65 AST (8–20 U/L) 124 85 Misc. Labs: Ammonia (11–35 mcg/dL) 35 28 © 2016 Keith Rischer/www.KeithRN.com 3. What interventions will you initiate based on this priority? Nursing Interventions: Rationale: Expected Outcome: 4. What educational/discharge PRIORITIES will be needed to develop a teaching plan for this patient and/or family? RELEVANT Data from Present ProblemRow1: Clinical SignificanceRow1: Current VS: PQRST Pain Assessment 5th VS: Nothingnothing: P 110 regular: Quality: Ache: R 20: RUQepigastric: BP 12888: Severity: 610: O2 sat 95 RA: Timing: Continuous: BP: Lying: RELEVANT VS DataRow1: RationaleRow1: Current Assessment: GENERAL APPEARANCE: Appears uncomfortable body tense occasional facial grimacing: RESP: CARDIAC: NEURO: Alert oriented to person place time and situation x4: GI: GU: SKIN: RELEVANT Assessment DataRow1: RationaleRow1_2: Current: Previous: WBC 45110 mm 3: HighLowWNL128: Four Principles of Clinical Reasoning Discussion

What the clinical reasoning case requires

01Identification and interpretation of relevant clinical data from the present problem.
02Identification of the relevant vital sign data and its clinical significance.
03A trending judgement about whether the patient is stable or unstable.
04A statement of the essence of the current clinical situation.
05The nursing priority and plan of care.