Telling the three emergencies apart
Diabetes emergencies are among the most reliably testable topics because the three presentations are genuinely distinct once you know what to look for. Speed of onset is the first discriminator. Hypoglycaemia develops in minutes. Diabetic ketoacidosis develops over hours to a day. Hyperglycaemic hyperosmolar state develops over days, which is why those clients arrive so profoundly dehydrated.
The second discriminator is the client. DKA classically affects clients with type 1 diabetes, because absolute insulin deficiency forces fat breakdown and ketone production. HHS classically affects older clients with type 2 diabetes, who retain enough insulin to suppress ketogenesis but not enough to control glucose, and who often have an infection or illness as the trigger.
The third discriminator is the acid-base picture. DKA produces a metabolic acidosis with Kussmaul respirations, which are deep rapid breaths compensating by blowing off carbon dioxide, plus the fruity acetone breath odour. HHS produces hyperosmolality and neurological change without significant acidosis. If the stem mentions Kussmaul breathing or fruity breath, you are in DKA territory.
- •Minutes = hypoglycaemia; hours = DKA; days = HHS
- •Type 1 with ketones = DKA; older type 2 without ketones = HHS
- •Kussmaul respirations and fruity breath are DKA signatures
- •Neurological change dominates HHS presentations
Recognition and treatment sequences
Hypoglycaemia is treated by the rule of fifteen. Give fifteen grams of a fast-acting carbohydrate such as four ounces of juice, regular soft drink or glucose tablets; wait fifteen minutes; recheck the glucose; repeat if still below the target. Once the level is corrected, provide a longer-acting snack containing protein and carbohydrate if a meal is not imminent. If the client is unconscious or cannot swallow safely, nothing is given by mouth; use intramuscular or subcutaneous glucagon or intravenous dextrose.
DKA management follows a sequence that appears repeatedly as an ordered-response item. Fluids come first, because these clients are severely volume depleted and perfusion must be restored. Then insulin by continuous infusion to close the ketone gap. Then electrolytes, especially potassium, which must be checked before insulin is started and monitored continuously because insulin drives potassium into the cells and can precipitate dangerous hypokalaemia even when the initial level looked normal or high.
HHS management is similar in structure but even more fluid-focused, since the fluid deficit is larger. Insulin requirements are typically lower, correction is slower to avoid rapid osmolality shifts and cerebral oedema, and the precipitating cause — commonly infection — must be identified and treated.
| Feature | Hypoglycaemia | DKA | HHS |
|---|---|---|---|
| Onset | Minutes | Hours | Days |
| Typical client | Any, often after missed meal or excess insulin | Type 1 diabetes | Older adult with type 2 diabetes |
| Glucose | Below 70 mg/dL | Usually 250–600 mg/dL | Often above 600 mg/dL |
| Ketones and acidosis | Absent | Present, metabolic acidosis | Minimal or absent |
| Breathing | Normal or rapid | Kussmaul, fruity odour | Usually normal |
| First action | 15 g fast carbohydrate | IV fluids, then insulin | Aggressive IV fluids |
Insulin, sick days and self-management teaching
Teaching items dominate the non-emergency half of diabetes content. Sick-day rules are heavily tested: never omit insulin during illness even if eating less, check glucose more frequently, check ketones when glucose is persistently high in type 1 diabetes, maintain fluid intake, use carbohydrate-containing fluids if unable to eat solid food, and contact the provider for persistent vomiting, ketones or glucose that will not come down.
Foot care is a guaranteed teaching topic. Inspect the feet daily including between the toes, wash with lukewarm water and dry thoroughly, moisturise but not between the toes, cut nails straight across or have them cut professionally, never walk barefoot, never use heating pads or hot water bottles on the feet, and wear well-fitting shoes checked for foreign objects before wearing.
Exercise teaching is a frequent source of distractors. Check glucose before, during prolonged activity and after; carry a fast-acting carbohydrate; avoid exercising at the peak action time of insulin; and do not exercise when glucose is very high with ketones present, because exercise then worsens ketosis rather than lowering glucose.
- •Never omit insulin during illness — requirements often increase
- •Foot care: daily inspection, no barefoot walking, no heat sources
- •Carry fast-acting carbohydrate during exercise
- •Do not exercise with high glucose plus ketones
Studying diabetes efficiently
Diabetes appears in adult health, pharmacology, maternity, paediatrics and management of care, making it one of the highest-frequency topics on the exam. Build a single comparison table of the three emergencies, rehearse it weekly, and separately drill insulin onset, peak and duration, since timing questions are common and objectively scorable.
When reviewing questions, distinguish assessment items from action items. A stem asking what the nurse observes is testing recognition; a stem asking what the nurse does first is testing the treatment sequence. Candidates who blur the two lose marks on questions they actually understood.
Pair this guide with the insulin and diabetes article for medication timing detail, and with the fluid balance guide, since both DKA and HHS are fundamentally fluid and electrolyte emergencies wearing an endocrine label.