Med-Surg · Endocrine
Diabetes, DKA & HHS
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Prepared for Pass the Shift (owner: Kristina, RN). Always follow your facility’s protocols, provider orders, and current drug references.
1. Overview and Pathophysiology
Diabetes mellitus is chronic hyperglycemia from insulin deficiency, resistance, or both.
| Type | Core problem |
|---|---|
| Type 1 | Autoimmune beta-cell destruction → absolute insulin deficiency |
| Type 2 | Insulin resistance + relative insulin deficiency; progressive |
| Gestational / other | Pregnancy hormones or secondary causes |
(more common in T1): insulin lack → lipolysis → ketones → metabolic acidosis + hyperglycemia + dehydration.
(more common in T2 older adults): extreme hyperglycemia and hyperosmolarity with profound dehydration; minimal ketones/acidosis.
Hypoglycemia kills faster than hyperglycemia in the short term—treat promptly.
2. Causes and Risk Factors
- T1: autoimmune, genetic predisposition
- T2: obesity, inactivity, family history, age, metabolic syndrome, certain ethnic groups
- DKA/HHS triggers: infection, missed insulin, new diagnosis, MI/stroke, steroids, SGLT2-associated euglycemic DKA
- Hypoglycemia: too much insulin/secretagogue, skipped meals, exercise, alcohol
3. Signs and Symptoms
- Hyperglycemia: polyuria, polydipsia, polyphagia, blurred vision, fatigue, infections, poor wound healing
- Hypoglycemia: shakiness, diaphoresis, tachycardia, hunger, irritability, confusion, seizure/coma
- DKA: Kussmaul respirations, fruity breath, abdominal pain, vomiting, dehydration, altered LOC
- HHS: profound dehydration, neurologic changes (coma possible), often no Kussmaul/fruity breath
4. Diagnostics and Labs
Lab reference ranges vary by laboratory. Always use your facility’s ranges.
| Test | Typical / diagnostic notes | Nursing relevance |
|---|---|---|
| Fasting glucose | 70–99 mg/dL typical; ≥ 126 diabetes (repeat) | Monitor trends |
| Random / OGTT | ≥ 200 with symptoms / 2-h ≥ 200 | Diagnosis per ADA |
| HbA1c | < 5.7% normal; ≥ 6.5% diabetes; many goals < 7% | 2–3 month average |
| Capillary glucose | — | Point-of-care decisions |
| ABG / bicarbonate / anion gap | Acidosis + gap in DKA | Track resolution |
| Serum ketones | Elevated in DKA | Bedside beta-hydroxybutyrate when available |
| Osmolality | Markedly high in HHS | Neurologic risk |
| Potassium | May look “normal” while total body K⁺ is low | Insulin drives K⁺ intracellular—replace carefully |
5. Priority Nursing Assessments
- Bedside glucose; neuro status; hydration (skin, mucosa, VS, urine output)
- Respiratory pattern (Kussmaul); GI symptoms
- ECG / K⁺ before and during insulin infusions
- Feet/skin inspection; infection signs
- Hypoglycemia risk around peak insulin times
- Teaching barriers: vision, literacy, cost, fear of needles
6. Priority Nursing Interventions
Hypoglycemia (conscious, can swallow): 15 g fast-acting carb → recheck 15 min → repeat as needed, then complex snack if meal not soon. Unconscious / NPO: IV dextrose or glucagon per protocol.
DKA (typical sequence—follow protocol):
- ABCs and IV access; continuous monitoring
- IV fluids first (usually NS bolus then per protocol)
- Check/replace K⁺—if K⁺ is critically low, replace before insulin
- IV regular insulin infusion
- Add dextrose to fluids when glucose approaches ~200–250 mg/dL to avoid hypoglycemia while clearing ketones
- Treat precipitant (infection, etc.)
HHS: aggressive fluids, careful insulin, electrolyte replacement, neurologic monitoring; slower osmolality correction.
General: sick-day rules (never skip all insulin), rotate injection sites, foot care, vaccine support.
7. Medications
| Class / examples | Role | Nursing considerations |
|---|---|---|
| Rapid insulin (lispro, aspart) | Prandial / correction | Eat with dose; peak ~1 h |
| Regular insulin | IV infusions; prandial | Only regular routinely IV |
| NPH | Intermediate basal | Peak risk hypoglycemia mid-day/night |
| Long-acting (glargine, degludec) | Basal | Usually don’t mix with others |
| Mixing rule | Clear before cloudy | Regular then NPH when combining |
| Metformin | T2 first-line | Hold around contrast/AKI risk; GI side effects; lactic acidosis rare |
| Sulfonylureas | Increase insulin release | Hypoglycemia risk |
| GLP-1 RAs | Glucose + weight | Nausea; boxed warning considerations per agent |
| SGLT2 inhibitors | Glucose / cardio-renal benefit | Genital infections; euglycemic DKA; hold perioperatively per order |
8. Patient Education
- Glucose targets and when to call (per care team)
- Rule of 15; always carry carbs; medical ID
- Insulin storage, site rotation, sharps disposal
- Foot care: daily inspection, closed shoes, professional nail care if neuropathy
- Sick days: check glucose/ketones more often; take basal insulin; sip fluids; call if vomiting
- HbA1c meaning; eye/dental/kidney screening schedule
9. Complications
- Acute: hypoglycemia, DKA, HHS, infection
- Chronic: retinopathy, nephropathy, neuropathy, CVD, PAD, gastroparesis, foot ulcers/amputation
- Treatment-related: lipohypertrophy, weight gain, euglycemic DKA on SGLT2i
10. Memory Aids
- “15 grams, 15 minutes”
- “DKA = Dig Fast Ketones Acid; HHS = Hot Heavy Sugar”
- “Fluids, then K check, then insulin” (protocol-guided)
- “Clear before cloudy”
- “Only regular IV”
11. NCLEX-Style Practice Questions
1. Fingerstick glucose 58 mg/dL; client alert and can swallow. First action?
A. Give IM glucagon immediately
B. Give ~15 g fast-acting carbohydrate and recheck in 15 minutes
C. Give scheduled glargine early
D. Recheck in 2 hours without treating
Answer: B. Rule of 15 for a conscious client.
2. DKA client ordered for insulin infusion; K⁺ is 3.1 mEq/L. Best action?
A. Start insulin immediately
B. Notify provider—replace potassium before insulin per guidelines/protocol
C. Give IV potassium push
D. Restrict all fluids
Answer: B. Insulin lowers serum K⁺ further; critically low K⁺ is replaced first.
3. Which finding better supports HHS than DKA?
A. Fruity breath and Kussmaul respirations
B. Glucose > 600 mg/dL with minimal ketones in an older adult with T2DM
C. Anion-gap metabolic acidosis with large ketones
D. Rapid onset in a child with T1DM
Answer: B. HHS features extreme hyperglycemia/hyperosmolarity without significant ketoacidosis.
4. Correct teaching about metformin and CT with IV contrast?
A. Always double the metformin dose the day of contrast
B. Follow protocol—often hold around contrast if eGFR risk, then restart when renal function OK
C. Metformin dissolves contrast
D. No interaction exists ever
Answer: B. Concern is lactic acidosis if contrast-related AKI occurs.
5. Which insulin can be given IV?
A. Glargine
B. NPH
C. Regular
D. Detemir only
Answer: C. Regular insulin is the standard IV insulin.
References
American Diabetes Association. (2026). Standards of care in diabetes—2026. https://diabetesjournals.org/care
MedlinePlus. (n.d.). Diabetes. National Library of Medicine. Retrieved October 15, 2026, from https://medlineplus.gov/diabetes.html
National Council of State Boards of Nursing. (2026). 2026 NCLEX-RN test plan. https://www.nclex.com/test-plans.page
Lizzo, J. M., Goyal, A., & Gupta, V. (2023). Adult diabetic ketoacidosis. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK560723/
Adeyinka, A., & Kondamudi, N. P. (2023). Hyperosmolar hyperglycemic syndrome. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK482142/