Diabetes, Hypoglycemia, DKA, and HHS
Key Takeaways
- CMSRN questions often hinge on whether glucose problems are urgent because of neuroglycopenia, dehydration, potassium shifts, or acidosis.
- Insulin safety requires matching type, peak, meal timing, glucose trend, renal function, and NPO status.
- DKA usually presents with acidosis and ketosis; HHS usually presents with profound dehydration and very high glucose with minimal ketosis.
- Do not delay treatment of symptomatic hypoglycemia while waiting for a meal tray or routine provider rounding.
- Education should connect sick-day rules, foot care, medication timing, and when to seek help.
Diabetes, Hypoglycemia, DKA, and HHS
Case anchor
A 64-year-old adult with type 2 diabetes is admitted with pneumonia, glucose 438 mg/dL, dry mucous membranes, heart rate 116/min, potassium 4.0 mEq/L, creatinine 1.6 mg/dL, and new confusion. The CMSRN priority is not just lowering glucose. The nurse assesses perfusion, mental status, hydration, infection severity, medication history, and whether this is uncomplicated hyperglycemia, diabetic ketoacidosis (DKA), or hyperosmolar hyperglycemic state (HHS).
Focused assessment
Diabetes assessment starts with the patient, not the number. Check level of consciousness, speech, diaphoresis, tremor, weakness, nausea, abdominal pain, Kussmaul respirations, fruity breath, orthostatic blood pressure, skin turgor, urine output, weight change, and recent intake. Ask about missed insulin, steroids, infection symptoms, alcohol use, pump problems, vomiting, renal disease, and last meal. In older adults, hypoglycemia may present as confusion, behavior change, dizziness, or falls rather than classic shakiness.
Lab patterns
| Problem | Expected pattern | Nursing concern |
|---|---|---|
| Hypoglycemia | Usually glucose less than 70 mg/dL, symptoms may occur higher if rapid drop | Seizure, fall, aspiration, neurologic injury |
| DKA | Hyperglycemia, anion gap metabolic acidosis, ketones, dehydration | Potassium shift, cerebral edema risk, shock |
| HHS | Very high glucose, high osmolality, severe dehydration, minimal ketones | Thrombosis, seizures, coma, renal injury |
Potassium deserves special attention. A patient in DKA may have a normal or high serum potassium while total body potassium is depleted. When insulin therapy begins, potassium moves into cells and serum potassium can fall quickly. The nurse verifies current potassium, cardiac monitoring orders, replacement fluids, and urine output before and during insulin infusion.
Nursing interventions
For symptomatic hypoglycemia in an awake patient who can swallow, give 15 g rapid carbohydrate, recheck glucose in 15 minutes, and repeat per protocol. Once recovered, provide longer-acting carbohydrate or a meal if the next meal is not soon. If the patient is NPO, unable to swallow, seizing, or has decreased consciousness, use IV dextrose or glucagon per protocol and protect the airway.
For DKA or HHS, expect large-volume isotonic fluids first unless contraindicated, then insulin infusion after potassium safety is addressed. Monitor glucose hourly if on infusion, strict intake and output, vital signs, neuro status, telemetry when indicated, and serial electrolytes. Report declining mental status, hypotension, chest pain, potassium abnormalities, worsening acidosis, or urine output less than expected. With HHS, dehydration may be extreme, so watch for fluid overload in heart failure or CKD while still recognizing that under-resuscitation is dangerous.
Medication risks
Insulin errors are high-risk events. Confirm insulin name, concentration, route, timing, pump status, and whether orders are basal, correctional, prandial, or infusion. Do not hold basal insulin automatically for type 1 diabetes without clarification, even when NPO, because lack of basal insulin can precipitate DKA. Sulfonylureas can cause prolonged hypoglycemia, especially in older adults and renal impairment. Steroids raise glucose and often require planned monitoring rather than reactive correction alone.
SGLT2 inhibitors can be associated with euglycemic DKA; report nausea, abdominal pain, tachypnea, ketones, or acidosis even when glucose is not severely elevated.
Education and safety
Case-based teaching is most effective: If sick with fever or vomiting, continue diabetes monitoring, follow the prescribed sick-day plan, check ketones if instructed, maintain fluids, and call early for persistent vomiting, moderate or large ketones, confusion, or glucose that remains high despite correction. Teach foot inspection, footwear, skin care, medication timing, hypoglycemia treatment, carrying glucose, and medical identification. Before discharge, confirm the patient can obtain insulin, supplies, strips, food, and follow-up. A perfect plan that the patient cannot afford is unsafe.
Escalation cues
Escalate for altered mental status, seizure, inability to swallow during hypoglycemia, suspected DKA or HHS, persistent glucose extremes, potassium less than 3.3 or rapidly falling during insulin therapy, hypotension, chest pain, acute kidney injury, or signs of sepsis. On CMSRN-style questions, choose the action that prevents immediate harm: airway protection, rapid glucose treatment, fluid resuscitation, potassium verification, and timely provider notification.
A patient with type 1 diabetes is NPO for a procedure. The bedtime glucose is 146 mg/dL, and the MAR includes basal insulin glargine. What is the best nursing action?
A patient on an insulin infusion for DKA has a potassium of 3.1 mEq/L. Which action has priority?
An older adult with type 2 diabetes becomes diaphoretic and confused before lunch. The bedside glucose is 52 mg/dL, and the patient is awake and able to swallow. What should the nurse do first?