Type 2 Diabetes Clinical Reasoning Case Study (Harding & Snyder Case Study 91): Nursing Guide with Model Answers

How to use this guide: the textbook case and its questions are copyrighted, so they are not reproduced here. Instead, this guide explains the clinical content the case tests and walks through an original practice case with model answers. Use it to study and to check your reasoning, then answer the questions in your textbook in your own words. It is not an answer key.

Type 2 diabetes: what the case tests

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease marked by insulin resistance in muscle, fat and liver tissue and a progressive decline in beta-cell function. At first the pancreas compensates by making more insulin. Over time beta cells cannot keep up, the liver releases too much glucose, and blood glucose rises (Harding et al., 2023). Major risk factors include overweight and obesity, physical inactivity, family history, age, history of gestational diabetes, prediabetes and certain racial and ethnic backgrounds.

Clinical reasoning cases on T2DM usually test whether you can interpret glucose and A1C values, recognize hyperglycemia and hypoglycemia, manage oral agents and insulin safely during acute illness, prevent complications such as foot ulcers and teach self-management. The American Diabetes Association’s Standards of Care in Diabetes is updated every year and is the main practice guideline (American Diabetes Association Professional Practice Committee [ADA], 2026).

Original practice case

Clinical reasoning questions and model answers

1. What explains Mr. Ortiz’s high glucose and symptoms?

Insulin resistance and reduced insulin secretion cause chronic hyperglycemia. Acute infection makes it worse because stress hormones (cortisol, epinephrine, glucagon) raise glucose further. When glucose exceeds the kidney’s threshold, glucose spills into the urine and pulls water with it (osmotic diuresis), causing polyuria, polydipsia, fatigue and dehydration. High glucose also impairs white blood cell function and wound healing, which helps explain the infected ulcer.

2. Interpret the laboratory results.

3. Should metformin be continued in the hospital?

Usually no. Metformin is typically held during acute illness, dehydration, worsening kidney function or before iodinated contrast studies because of the rare risk of lactic acidosis. It is contraindicated when eGFR is below 30 mL/min/1.73 m². Most hospitalized patients with high glucose are managed with insulin instead, and oral agents are resumed before discharge when it is safe (ADA, 2026). The nurse should clarify the order with the provider rather than give the dose automatically.

4. What insulin regimen is preferred, and why not a sliding scale alone?

For noncritically ill patients who are eating, the preferred regimen is scheduled basal insulin (for example, glargine), prandial (mealtime) insulin and a correction dose for high readings. Sliding-scale insulin alone only reacts to high glucose after it happens and is discouraged as the only treatment (ADA, 2026). A typical hospital glucose target is 100–180 mg/dL. Nursing responsibilities include checking glucose before meals and at bedtime, coordinating rapid-acting insulin with meal tray delivery, and holding or clarifying mealtime insulin if the patient is NPO or not eating.

5. At 0300 on day 2, Mr. Ortiz is sweaty, shaky and confused. His glucose is 58 mg/dL. What should the nurse do?

This is hypoglycemia (below 70 mg/dL). Act immediately:

• If he can swallow safely, give 15 g of fast-acting carbohydrate (for example, 4 oz of juice or glucose tablets).
• Recheck glucose in 15 minutes and repeat treatment if it is still below 70 mg/dL (the “rule of 15”).
• Once glucose is normal, give a snack or meal containing protein and complex carbohydrates if the next meal is more than an hour away.
• If he cannot swallow or is unresponsive, give glucagon or IV dextrose per protocol. Never give oral fluids to a patient who cannot protect the airway.
• Notify the provider, document, and look for the cause: a basal dose that is too high, a missed bedtime snack or reduced eating because of illness.

6. What foot assessments and care are needed?

Peripheral neuropathy and poor circulation make people with diabetes prone to unnoticed injuries. Assess the ulcer (size, depth, drainage, odor, surrounding redness), pedal pulses, capillary refill, skin temperature and sensation (monofilament testing). Elevate the foot, offload pressure, follow wound care orders and give antibiotics on time. Teach daily foot inspection with a mirror, washing and drying carefully between toes, never walking barefoot, wearing well-fitted shoes and getting regular podiatry care (ADA, 2026).

7. Which tasks can be delegated to unlicensed assistive personnel (UAP)?

Depending on agency policy, UAP can measure capillary blood glucose, take vital signs, record intake and output, and help with hygiene. They should report results and any symptoms to the nurse right away. Assessing hypoglycemia, giving insulin, evaluating the wound and teaching remain registered nurse responsibilities.

8. What should discharge teaching include?

• Medications: how and when to take each drug; insulin pen technique, site rotation and storage if insulin continues at home.
• Glucose monitoring: how often to check and what to do with high or low readings. Continuous glucose monitoring (CGM) may be recommended (ADA, 2026).
• Hypoglycemia: symptoms, the rule of 15 and carrying a carbohydrate source.
• Sick-day rules: keep taking insulin, check glucose more often, drink fluids and call the provider if he cannot eat or glucose stays high.
• Nutrition and activity: referral to diabetes self-management education and a dietitian; consistent carbohydrate intake; regular physical activity once the foot heals.
• Complication prevention: yearly eye and kidney checks, blood pressure and cholesterol control and daily foot care.

Use teach-back to confirm understanding. For a broader look at patient teaching, see our guide to the nurse’s role as health educator.

9. Which long-term medications might be added?

For people with T2DM and established cardiovascular disease, heart failure or chronic kidney disease, the ADA recommends medications with proven organ protection, such as SGLT2 inhibitors (empagliflozin, dapagliflozin) and GLP-1 receptor agonists (semaglutide, liraglutide), regardless of A1C (ADA, 2026). Nurses teach about side effects: genital yeast infections and dehydration with SGLT2 inhibitors, and nausea and reduced appetite with GLP-1 receptor agonists.

Sample nursing care plan

Frequently asked questions

Related reading: another type 2 diabetes case study, diabetic data analysis for nurse informaticists, subjective vs. objective nursing data and teach-back in daily practice.

Conclusion

Type 2 diabetes cases ask nurses to connect pathophysiology with safe action: recognize how illness raises glucose, interpret A1C and kidney function, hold metformin when it is unsafe, use basal-bolus insulin, treat hypoglycemia quickly and protect the feet. The work does not end at discharge. Clear, tailored teaching and follow-up are what prevent the next admission.

References

American Diabetes Association Professional Practice Committee. (2026). Standards of care in diabetes—2026. Diabetes Care, 49(Suppl. 1).

Harding, M. M., Kwong, J., Hagler, D., & Reinisch, C. (2023). Lewis’s medical-surgical nursing: Assessment and management of clinical problems (12th ed.). Elsevier.

Harding, M. M., & Snyder, J. S. (2019). Clinical reasoning cases in nursing (7th ed.). Elsevier Mosby.