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Diabetic Emergencies
DKA & HHS

Recognizing and treating two life-threatening hyperglycemic crises: diabetic ketoacidosis and hyperosmolar hyperglycemic state.

NCLEX-RN

What Is a Diabetic Emergency?

A diabetic emergency happens when blood glucose moves dangerously outside the normal range. The two hyperglycemic crises are DKA (diabetic ketoacidosis) and HHS (hyperosmolar hyperglycemic state).

Key Terms

DKA
Insulin deficiency leads to fat breakdown, producing ketones and metabolic acidosis. Common in type 1 diabetes.
HHS
Severe hyperglycemia with profound dehydration but minimal ketones. Common in type 2 diabetes.
Ketones
Acidic byproducts of fat metabolism that lower blood pH and cause fruity breath.

The Pathophysiology Chain

Insulin lack (absolute/relative) High blood glucose Osmotic diuresis Dehydration & electrolyte loss DKA path: fat broken down → ketones → acidosis HHS path: extreme glucose, no major ketones, severe fluid loss

Diagnostic Criteria

DKAHHS
Glucose\( > 250 \text{ mg/dL} \)\( > 600 \text{ mg/dL} \)
Arterial pH\( < 7.30 \)\( > 7.30 \)
Bicarbonate\( < 18 \text{ mEq/L} \)\( > 18 \text{ mEq/L} \)
KetonesPositiveNegative / trace
OsmolalityVariable\( > 320 \text{ mOsm/kg} \)

The Serum Osmolality Rule

Osmolality measures particle concentration in blood. It rises sharply in HHS, explaining the profound dehydration and altered mental status.

DKA vs HHS: Key Distinction

DKA Hallmarks
Rapid onset (hours), Kussmaul breathing, fruity acetone breath, abdominal pain, positive ketones, acidosis.
HHS Hallmarks
Slow onset (days), extreme thirst, severe dehydration, altered mental status, very high glucose, no significant ketosis.

Treatment Sequence

1
Fluids first. IV normal saline (\( 0.9\% \text{ NaCl} \)) to correct dehydration and restore perfusion.
2
Insulin. Continuous IV regular insulin infusion to lower glucose gradually.
3
Potassium. Monitor and replace potassium before and during insulin therapy.
4
Add dextrose. When glucose falls to \( \approx 200-250 \text{ mg/dL} \), add dextrose to prevent hypoglycemia.

Why Potassium Matters

As insulin drives glucose into cells, it also pulls potassium into cells, dropping serum potassium quickly. Insulin can cause life-threatening hypokalemia.

Example 1: Identify the Crisis

Example 2: Identify the Crisis

Example 3: Calculate Osmolality

Common Mistakes

✕ Insulin before fluids
Fluids restore perfusion first. Insulin alone can worsen shock and drop potassium dangerously.
✕ Ignoring potassium
Forgetting to check and replace potassium can trigger fatal cardiac arrhythmias.
✕ Lowering glucose too fast
Rapid drops risk cerebral edema. Lower glucose gradually and add dextrose at \( \approx 200-250 \).

Summary Comparison

DKAHHS
Typical typeType 1Type 2
OnsetHoursDays
KetonesPresentAbsent
BreathingKussmaulNormal
HallmarkAcidosisDehydration
First treatmentIV fluidsIV fluids

Don't Forget Hypoglycemia

Low blood glucose (\( < 70 \text{ mg/dL} \)) is also an emergency: shakiness, sweating, confusion, and rapid heart rate appear quickly.

Question 1 of 5

A client with type 1 diabetes presents with glucose \( 410 \text{ mg/dL} \), \( \text{pH } 7.16 \), positive ketones, and fruity breath. What is the priority crisis?

Question 2 of 5

Which intervention should the nurse perform first for a client in DKA?

Question 3 of 5

Before starting an insulin infusion, the nurse notes serum potassium of \( 3.1 \text{ mEq/L} \). What action is appropriate?

Question 4 of 5

A 75-year-old with type 2 diabetes has glucose \( 750 \text{ mg/dL} \), \( \text{pH } 7.35 \), negative ketones, and confusion. This best describes:

Question 5 of 5

During DKA treatment, glucose drops to \( 220 \text{ mg/dL} \). What does the nurse anticipate adding?