DKA Nursing Guide 2026: Diabetic Ketoacidosis Assessment & Management
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This article was created with AI assistance.
DKA is a life-threatening emergency. Mortality is 1–5% and higher in elderly or delayed presentations. Early aggressive fluid resuscitation and insulin therapy are key.
Pathophysiology (Simplified)
DKA occurs when insulin is severely deficient (or absent) and counter-regulatory hormones (glucagon, cortisol, catecholamines) are elevated:
- No insulin → cells cannot uptake glucose → hyperglycemia
- Body thinks it is starving → breaks down fat → free fatty acids → ketones
- Ketones are acids → metabolic acidosis (anion gap)
- Hyperglycemia → osmotic diuresis → profound dehydration + electrolyte loss
- Total body K+ is depleted (even though serum K+ may be normal or high initially due to acidosis shifting K+ out of cells)
DKA Diagnostic Criteria
| Parameter | Mild DKA | Moderate DKA | Severe DKA |
|---|
| Plasma glucose | >250 mg/dL | >250 mg/dL | >250 mg/dL |
| Arterial pH | 7.25–7.30 | 7.00–7.24 | <7.00 |
| Serum bicarb | 15–18 mEq/L | 10–15 mEq/L | <10 mEq/L |
| Urine/serum ketones | Positive | Positive | Positive |
| Anion gap | >10 | >12 | >12 |
| Mental status | Alert | Alert/drowsy | Stupor/coma |
Anion gap = Na − (Cl + HCO3). Normal is 8–12. Elevated AG = unmeasured anions (ketones, lactate, etc.).
Nursing Assessment
Classic DKA Presentation
- Polydipsia, polyuria, polyphagia (the 3 Ps) — often preceding days
- N/V, abdominal pain — hallmark symptoms
- Kussmaul respirations — deep, rapid breathing to blow off CO2 (respiratory compensation)
- Fruity/acetone breath — ketone exhalation
- Dehydration signs: dry mucous membranes, poor skin turgor, tachycardia, hypotension
- Altered mental status in severe cases
Precipitating Causes (the 6 I's)
- Infection (most common — UTI, pneumonia, cellulitis)
- Inadequate insulin (missed doses, pump failure)
- Ischemia/Infarction (MI can precipitate DKA)
- Inflammation (pancreatitis)
- Intoxication (alcohol, cocaine)
- Iatrogenic (steroids, atypical antipsychotics)
Fluid Resuscitation
Fluids FIRST, then insulin. Never start insulin without replacing volume first — insulin drives K+ into cells, worsening hypokalemia. Also, dehydration must be addressed to help clear ketones.
- 0.9% NS (normal saline): 1–1.5 L IV bolus in first hour; then 250–500 mL/hr based on hemodynamics
- When glucose falls to ~200–250 mg/dL: switch to D5 0.45% NS (to allow continued insulin without hypoglycemia)
- Total fluid deficit is typically 3–6 liters — replace over 24–48 hours
- Monitor for fluid overload in elderly or cardiac patients
Insulin Therapy
| Step | Action | Key Nursing Checks |
|---|
| 1. Check K+ FIRST | Hold insulin if K+ <3.5 mEq/L | K+ must be ≥3.5 before starting insulin — replace K+ first |
| 2. Insulin bolus (optional) | Regular insulin 0.1 units/kg IV bolus | Confirm weight; use per institution protocol |
| 3. Insulin drip | Regular insulin 0.1 units/kg/hr continuous infusion | Infuse via dedicated IV line or port; never piggyback with fat emulsions |
| 4. Titrate drip | Goal: glucose drop 50–75 mg/dL/hr | If glucose drops <50/hr — double rate; if drops >75/hr — reduce rate |
| 5. Switch to D5 fluid | When glucose reaches 200–250 mg/dL | Continue insulin until ketosis resolved; don't stop drip when glucose normalizes |
| 6. Transition to SubQ | When pH >7.30, bicarb >18, AG <12 | Give first SubQ dose 1–2 hrs BEFORE stopping drip (prevents rebound) |
Common mistake: Stopping insulin drip when glucose normalizes but ketosis persists. Continue drip with D5 fluids until BOTH glucose AND acidosis resolve.
Electrolyte Management
Potassium — Most Critical
| Serum K+ Level | Action |
|---|
| <3.5 mEq/L | HOLD insulin. Replace K+ first (40 mEq/hr max peripherally; >10 mEq/hr central). Recheck before starting insulin. |
| 3.5–5.0 mEq/L | Add 20–40 mEq KCl to each liter of IV fluid. Proceed with insulin. |
| >5.0 mEq/L | Start insulin. Do NOT add K+ to fluids yet. Recheck K+ q1h. |
Why does K+ drop so dramatically? Insulin drives K+ into cells. As acidosis corrects, K+ shifts back in. Total body K+ is depleted regardless of initial serum level.
Other Electrolytes
- Phosphate: Usually low; replace if <1.0 mg/dL or symptomatic (hemolytic anemia, respiratory weakness)
- Magnesium: Check and replace; needed for K+ repletion to work
- Sodium: Corrected Na = measured Na + 1.6 × [(glucose – 100) / 100]; hyperglycemia falsely lowers Na
Monitoring Protocol
| Parameter | Frequency | Target |
|---|
| Blood glucose | q1h | Decrease 50–75 mg/dL/hr; goal 150–200 until ketosis resolved |
| Basic metabolic panel | q2–4h | K+ 3.5–5.0; bicarb trending up; AG closing |
| Urine output | Hourly (Foley preferred) | ≥0.5 mL/kg/hr |
| Vital signs | q1h minimum | HR and BP normalizing with fluids |
| Neuro status | q1–2h | Any mental status change = priority reassessment |
| Ketones (urine or serum) | q4h | Trending negative |
Cerebral edema is a rare but fatal complication, primarily in pediatric DKA. Signs: sudden headache, altered consciousness, pupil changes during treatment. Risk factor: too-rapid glucose correction or excess free water. Notify MD immediately.
DKA Resolution Criteria
All three must be met before transitioning off insulin drip:
- Blood glucose <200 mg/dL
- Serum bicarb ≥18 mEq/L (or venous pH >7.30)
- Anion gap ≤12 (or urine/serum ketones negative/trace)
SubQ Insulin Transition
- Give first SubQ insulin dose 1–2 hours BEFORE stopping insulin drip
- Patient must be tolerating PO fluids before SubQ transition
- Reassess and adjust home insulin regimen — DKA often signals the need for titration
- Identify and treat precipitating cause before discharge
- Diabetes education before discharge (sick day rules, when to call 911)
NCLEX High-Yield Points
- Check K+ BEFORE starting insulin — NEVER start insulin with K+ <3.5
- Kussmaul respirations = respiratory compensation for metabolic acidosis
- Fruity breath = ketone exhalation
- Switch IV fluid to D5 when glucose hits 200–250 — do NOT stop insulin drip
- Total body K+ is DEPLETED in DKA even if serum K+ is initially normal or high
- DKA resolution = glucose <200 + bicarb ≥18 + anion gap normal
- Most common precipitating cause = infection
- Give SubQ insulin 1–2h BEFORE stopping drip to prevent rebound
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