# Resolution Criteria and Transition to Subcutaneous Insulin — ADA 2024

## DKA Resolution Criteria

DKA is considered resolved when **all** of the following are met:

| Parameter | Target |
|---|---|
| **Beta-hydroxybutyrate** | < 0.6 mmol/L |
| **Venous pH** | >= 7.3 |
| **OR Bicarbonate** | >= 18 mmol/L |
| **Blood glucose** | Ideally < 200 mg/dL |

### Key Principles

- Beta-hydroxybutyrate is the **preferred marker** for monitoring DKA resolution, replacing the use of urine ketones or anion gap closure.
- Resolution is defined by ketone clearance and acid-base normalization, **not** by glucose normalization alone.
- If beta-hydroxybutyrate is unavailable, resolution may be assessed by pH >= 7.3 AND bicarbonate >= 18 mmol/L AND anion gap closure.
- Continue IV insulin infusion until resolution criteria are met, even if glucose has normalized (use dextrose-containing fluids to prevent hypoglycemia).

## HHS Resolution Criteria

HHS is considered resolved when **all** of the following are met:

| Parameter | Target |
|---|---|
| **Serum osmolality** | < 300 mOsm/kg |
| **Plasma glucose** | < 250 mg/dL |
| **Urine output** | > 0.5 mL/kg per hour |
| **Cognitive status** | Improved to baseline |

### Rate of Correction Targets (HHS)

| Parameter | Maximum Rate |
|---|---|
| **Glucose decline** | <= 90-120 mg/dL per hour |
| **Sodium decline** | <= 10 mmol/L per 24 hours |
| **Osmolality decline** | 3.0-8.0 mOsm/kg per hour |

Overly rapid correction increases the risk of cerebral edema.

## Transition From IV to Subcutaneous Insulin

### Prerequisites for Transition

Before transitioning from IV to subcutaneous insulin, the following conditions must be met:

1. DKA or HHS resolution criteria are met (see above)
2. Patient is able to eat
3. Patient is hemodynamically stable
4. No immediate surgical procedures planned

### Total Daily Dose (TDD) Calculation

| Method | Dose | When to Use |
|---|---|---|
| **Weight-based (insulin-naive)** | 0.5-0.6 units/kg per day | Patients with no prior insulin use |
| **Weight-based (high hypoglycemia risk)** | 0.3 units/kg per day | Elderly, renal impairment, low BMI, or history of hypoglycemia |
| **Prior home regimen** | Resume previous TDD | Patients previously well-controlled on known insulin regimen |
| **IV insulin requirement-based** | Extrapolate from last stable IV rate | Calculate 24-hour equivalent; reduce by 20-30% for safety |

### Basal-Bolus Regimen (Preferred)

- **Basal insulin:** 0.15-0.3 units/kg administered once daily (or divided twice daily).
  - Long-acting analogs preferred: insulin glargine or insulin degludec.
  - Intermediate-acting (NPH) may be used if analogs unavailable.
- **Bolus insulin:** Rapid-acting analog (lispro, aspart, glulisine) before meals.
  - Divide the remaining TDD (total minus basal) into pre-meal doses.

### Critical Overlap Period

- **Must overlap IV insulin infusion by 1-2 hours** after administering the first dose of subcutaneous basal insulin before discontinuing the IV infusion.
- Abrupt discontinuation of IV insulin without subcutaneous overlap leads to rebound hyperglycemia and risk of recurrent DKA.

### Transition Algorithm

```
DKA/HHS resolution criteria met AND patient tolerating oral intake?
  --> Calculate TDD
      --> Insulin-naive: 0.5-0.6 units/kg/day
      --> High hypoglycemia risk: 0.3 units/kg/day
      --> Known regimen: resume prior TDD

  --> Administer first dose of subcutaneous basal insulin
      --> Continue IV insulin for 1-2 hours after SC basal dose
      --> Then discontinue IV insulin infusion

  --> Start rapid-acting insulin with first meal
  --> Monitor glucose before meals and at bedtime
      --> Adjust doses as needed over next 24-48 hours

  --> If patient not yet eating:
      --> Continue IV insulin at current rate
      --> Reassess ability to eat every 4-6 hours
```

## Discharge Planning and Prevention

### Discharge Readiness Criteria

- Stable subcutaneous insulin regimen for at least 12-24 hours
- Blood glucose consistently 100-250 mg/dL on SC insulin
- Patient (or caregiver) trained on insulin administration technique
- Precipitating factor identified and addressed (or plan in place)

### Prevention of Recurrence

The consensus report emphasizes that discharge planning and prevention are critical components of DKA/HHS management:

| Intervention | Details |
|---|---|
| **Follow-up appointment** | Within 2-4 weeks post-discharge |
| **Insulin education** | Training on proper insulin administration, storage, and dose adjustment |
| **Sick day rules** | Written instructions for managing diabetes during illness (increase monitoring, never omit insulin, hydration, when to seek emergency care) |
| **Ketone monitoring** | Educate on blood (preferred) or urine ketone testing; provide supplies |
| **CGM consideration** | Continuous glucose monitoring offered to all patients post-discharge to reduce risk of recurrent crises |
| **Mental health screening** | Screen for depression (PHQ-9), disordered eating, and diabetes distress; psychological factors are common in recurrent DKA |
| **Social determinants** | Address socioeconomic barriers, food insecurity, insurance coverage, and medication affordability |
| **SGLT2 inhibitor review** | Discontinue if SGLT2 inhibitor contributed to DKA; not routinely recommended for reinitiation post-DKA |
| **Insulin pump assessment** | Review pump settings, infusion set practices, and alarm responses if pump-related DKA |

### Risk Factors for Recurrent DKA

- Psychological stress and psychiatric comorbidity
- Low socioeconomic status
- Younger age
- Substance abuse
- Prior history of recurrent DKA
- Inadequate follow-up care

## Special Considerations

### Insulin Pump Users

- After DKA resolution and transition to SC insulin, pump therapy may be resumed if:
  - The pump was not the cause of DKA (or the cause has been corrected)
  - Patient demonstrates competency in pump management
  - Appropriate follow-up with endocrinology is arranged

### Type 2 Diabetes Patients With DKA

- Consider whether ongoing insulin therapy is necessary or if the patient can transition to non-insulin agents after the acute episode resolves.
- Some patients with T2D who present with DKA (ketosis-prone diabetes) may eventually transition to oral agents, but this decision requires outpatient endocrinology follow-up.

### Checkpoint Inhibitor-Associated Diabetes

- Approximately 1-2% of patients receiving checkpoint inhibitors develop new-onset autoimmune diabetes with rapid progression and high DKA risk.
- These patients typically require lifelong insulin therapy.

## Limitations

- The optimal duration of overlap between IV and SC insulin (1-2 hours) is based on pharmacokinetic principles of long-acting insulin analogs rather than randomized trials.
- TDD calculations are initial estimates; significant dose adjustments are often required in the first 48-72 hours post-transition.
- The recommendation for CGM post-discharge is supported by evidence in T1D but has limited evidence specifically in post-DKA populations.
- Discharge readiness criteria are expert consensus-based and may need to be adapted based on local resources and patient circumstances.
