Insulin Management on Med-Surg: Sliding Scale, Basal-Bolus, Hypoglycemia Protocol

Insulin Management on Med-Surg: Sliding Scale, Basal-Bolus, Hypoglycemia Protocol

A practical guide for nurses, clinicians, and students.

What Is This?

Insulin management in medical-surgical (med-surg) units ensures safe glycemic control for hospitalized patients with diabetes or stress-induced hyperglycemia. You’ll use sliding-scale insulin (SSI), basal-bolus regimens, and hypoglycemia protocols to prevent complications like infections, delayed wound healing, or life-threatening hypoglycemia.

Why use it today? - ~30% of hospitalized patients have diabetes or hyperglycemia, increasing risks of morbidity and mortality. - Poor glucose control prolongs hospital stays and raises healthcare costs. - Standardized protocols reduce errors and improve patient outcomes.

Why It Matters

Real-World Impact

1. Prevents complications: Hyperglycemia (>180 mg/dL) impairs immune function, delays healing, and increases infection risk (e.g., post-op wounds, sepsis).
2. Reduces mortality: Tight glycemic control (140–180 mg/dL) lowers in-hospital death rates by ~20% in ICU patients (NICE-SUGAR trial).
3. Avoids hypoglycemia: Severe hypoglycemia (<40 mg/dL) causes seizures, coma, or cardiac arrest—a "never event" in hospitals.
4. Standardizes care: Protocols reduce variability in insulin dosing, a leading cause of medication errors.

Core Concepts

1. Types of Insulin in Hospital Settings

2. Key Protocols

• Sliding-Scale Insulin (SSI): Reactive dosing based on current blood glucose (BG) levels. Problem: Treats hyperglycemia after it occurs; doesn’t prevent it.
• Basal-Bolus Regimen: Proactive approach with basal (long-acting) + bolus (rapid-acting) insulin. Mimics natural insulin secretion.
• Hypoglycemia Protocol: Standardized steps to treat BG <70 mg/dL (or <54 mg/dL if severe).

3. Glycemic Targets in Hospitalized Patients

How It Works

1. Sliding-Scale Insulin (SSI)

How it works: - BG is checked before meals and at bedtime (ACHS). - Insulin dose is determined by a pre-set scale (e.g., "give 2 units if BG 150–200 mg/dL"). - Only uses short-acting insulin (e.g., Regular).

Example Scale (Hospital Standard): | BG (mg/dL) | Insulin Dose (Regular) | |----------------|----------------------------| | <70 | Hold insulin; treat hypoglycemia. | | 70–150 | 0 units | | 151–200 | 2 units | | 201–250 | 4 units | | 251–300 | 6 units | | 301–350 | 8 units | | >350 | Call provider. |

Limitations: - Reactive, not preventive: Doesn’t account for meals or basal needs. - Risk of "rollercoaster" BG: Peaks and crashes common.

2. Basal-Bolus Regimen

How it works:
1. Basal insulin: Long-acting (e.g., Glargine) covers 24-hour needs (like a pancreas at rest).
2. Bolus insulin: Rapid-acting (e.g., Lispro) covers meals (carb counting) + corrections (sliding scale).
3. Total Daily Dose (TDD): - New patients: 0.3–0.5 units/kg/day (adjust for obesity, steroids, stress). - Known diabetics: Use 50–80% of home dose (hospital stress increases insulin resistance).

Example Calculation: - Patient weight: 70 kg - TDD: 70 kg × 0.4 units/kg = 28 units/day - Basal: 50% of TDD = 14 units Glargine at bedtime. - Bolus: 50% of TDD = ~5 units Lispro before each meal (adjust for carb intake).

Correction Dose (Sliding Scale): - Add to bolus if BG is high before meals. - Example: 1 unit per 50 mg/dL over 150 mg/dL.

3. Hypoglycemia Protocol

When to act: BG <70 mg/dL (or <54 mg/dL if severe).

Step-by-Step Treatment:
1. Check BG (confirm with lab if possible).
2. Administer fast-acting carbs: - Alert patient: 15–20g glucose (e.g., 4 oz juice, 3–4 glucose tabs). - Unconscious/NPO: 25g IV dextrose (D50) or 1mg glucagon IM.
3. Recheck BG in 15 minutes: - If still <70 mg/dL, repeat treatment. - If >70 mg/dL, give complex carb (e.g., crackers, milk) if next meal is >1 hour away.
4. Notify provider if: - BG remains <70 mg/dL after 2 treatments. - Patient is NPO or unable to swallow.

Prevention: - Hold insulin if patient is NPO or eating poorly. - Adjust basal/bolus if hypoglycemia recurs.

Hands-On / Getting Started

Prerequisites

• Knowledge: Basic diabetes pathophysiology, insulin types, and BG monitoring.
• Tools: Glucometer, insulin syringes/pens, IV dextrose, glucagon kit.
• Patient data: Weight, home insulin regimen, diet status (NPO vs. eating).

Step-by-Step: Basal-Bolus Order Set

Scenario: 65-year-old male with T2DM, weight 80 kg, NPO for surgery tomorrow.

1. Calculate TDD:
2. 0.3 units/kg/day (conservative for NPO) = 24 units/day.
3. Basal insulin:
4. 50% of TDD = 12 units Glargine at 21:00.
5. Bolus insulin:
6. Hold (patient is NPO).
7. Correction scale:
8. 1 unit per 50 mg/dL over 150 mg/dL (e.g., 2 units if BG 250 mg/dL).
9. Monitoring:
10. Check BG Q6H (since NPO).
11. Treat hypoglycemia per protocol.

Expected Outcome: - BG 140–180 mg/dL with minimal hypoglycemia.

Common Pitfalls & Mistakes

Best Practices

1. Use basal-bolus for most patients:
2. SSI alone is only for short-term use (e.g., perioperative).
3. Check BG before insulin:
4. Never give insulin without a recent BG (risk of hypoglycemia).
5. Adjust for stress, steroids, or diet changes:
6. Increase TDD by 20–50% for stress hyperglycemia.
7. Document everything:
8. BG trends, insulin doses, hypoglycemia treatments.
9. Educate patients:
10. Teach signs of hypoglycemia and how to respond.

Tools & Frameworks

Real-World Use Cases

1. Post-Op Hyperglycemia:
2. Scenario: Patient with T2DM undergoes CABG; BG spikes to 250 mg/dL.

3. Action: Start basal-bolus (Glargine + Lispro) + correction scale. Monitor Q4H.

4. Steroid-Induced Hyperglycemia:

5. Scenario: Patient on high-dose prednisone for COPD; BG 300 mg/dL.

6. Action: Increase TDD by 50%; use rapid-acting corrections.

7. Hypoglycemia in NPO Patient:

8. Scenario: Patient with T1DM is NPO for endoscopy; BG 50 mg/dL.
9. Action: Hold insulin; give 25g IV D50; recheck in 15 min.

Check Your Understanding (MCQs)

Question 1

A 70 kg patient with T2DM is admitted for pneumonia. His home insulin is 30 units Glargine daily. What is the most appropriate hospital insulin regimen?

A) Continue 30 units Glargine + sliding scale Regular insulin. B) Hold all insulin; check BG Q6H. C) Reduce Glargine to 24 units + add Lispro 4 units before meals. D) Use sliding-scale Regular insulin only.

Correct Answer: C Explanation: Hospital stress increases insulin resistance. Reduce home basal by 20% (30-24 units) and add bolus insulin for meals. Why the distractors are tempting: - A: Continuing full home dose risks hypoglycemia (hospital stress may decrease needs). - B: Holding insulin risks hyperglycemia (infection worsens glucose control). - D: SSI alone is reactive and not ideal for long-term management.

Question 2

A patient on a basal-bolus regimen has a BG of 60 mg/dL before lunch. They are alert and able to swallow. What is the first action?

A) Give 1mg glucagon IM. B) Administer 4 oz orange juice. C) Hold the lunch bolus insulin. D) Recheck BG in 30 minutes.

Correct Answer: B Explanation: For alert patients, give 15–20g fast-acting carbs (e.g., juice). Glucagon is for unconscious patients. Why the distractors are tempting: - A: Glucagon is overkill for an alert patient. - C: Correct to hold insulin, but treatment comes first. - D: Delaying treatment risks worsening hypoglycemia.

Question 3

A nurse gives 8 units of Regular insulin for a BG of 320 mg/dL at 08:00. At 10:00, the patient’s BG is 50 mg/dL. What is the most likely cause?

A) The patient ate a high-carb breakfast. B) The insulin dose was too high for the patient’s sensitivity. C) The patient’s basal insulin was held. D) The glucometer was malfunctioning.

Correct Answer: B Explanation: Regular insulin peaks at 2–4 hours—the 10:00 BG drop suggests the dose was excessive for the patient’s insulin sensitivity. Why the distractors are tempting: - A: High-carb meals cause hyperglycemia, not hypoglycemia. - C: Basal insulin (e.g., Glargine) wouldn’t cause a rapid drop. - D: Possible, but less likely than an insulin dosing error.

Learning Path

1. Beginner:
2. Learn insulin types, onset/peak/duration.
3. Practice calculating TDD and basal-bolus splits.

4. Memorize hypoglycemia protocol steps.

5. Intermediate:

6. Compare SSI vs. basal-bolus regimens.
7. Adjust insulin for NPO, steroids, or stress.

8. Interpret BG trends and modify orders.

9. Advanced:

10. Design hospital insulin protocols.
11. Manage IV insulin infusions (ICU setting).
12. Teach patients insulin self-management at discharge.

Further Resources

Books

• Insulin Therapy: A Pocket Guide (ADA) – Quick reference for dosing.
• Greenspan’s Basic & Clinical Endocrinology – Pathophysiology of diabetes.

Courses

• ADA’s "Insulin Management in the Hospital" (link)
• AACN’s "Glycemic Control in Critical Care" (link)

Tools

• Yale Insulin Infusion Protocol (PDF)
• Glucose Management Apps: Glytec, EndoTool.

Communities

• r/diabetes (Reddit) – Patient/nurse discussions.
• ADA Professional Forums (link)

30-Second Cheat Sheet

1. Basal-bolus > SSI: Use Glargine (basal) + Lispro (bolus) for most patients.
2. Hypoglycemia rule: 15g carbs-recheck in 15 min.
3. NPO patients: Hold bolus; reduce basal by 20%.
4. Steroids: Increase TDD by 20–50%.
5. Never mix long-acting insulin (e.g., Glargine) with other types.

Related Topics

1. IV Insulin Infusions – For ICU or perioperative tight control.
2. Di