Inpatient Basal-Bolus Insulin Protocol

Seventeen pathways: starting insulin, titrating it, infusions, feeding, dialysis and discharge · v2.0

  • Enter the baseline once: age, weight, diabetes type, HbA1c where you have it, and the renal and dialysis status.
  • Then pick a pathway from the five groups: start, adjust, switch, feeding or special.
  • You get the total daily dose split into basal and prandial, with a correction scale built from this patient's insulin sensitivity factor.
  • The renal adjustment is applied for you, and the dialysate and feed glucose loads that drive the requirement are carried into the total.
  • Watch for the U-500 flag, which fires once the projected total passes 200 units a day.

  • Diabetic ketoacidosis and the hyperosmolar hyperglycaemic state, which have their own fluid, potassium and fixed-rate insulin protocols in the Ketoacidosis and Hyperosmolar State Pathway.
  • Children and adolescents. Every figure here is derived for adults of 18 years and above.
  • Insulin pumps and continuous subcutaneous insulin infusion. A patient admitted on a pump keeps it running under a diabetology opinion, or is converted using the conversion pathway with the total daily basal rate as the basal dose.
  • The choice of oral agent for a patient going home. See Outpatient Diabetes Management, and Diabetes Classification where the type is genuinely in doubt.
  • The illness that put the patient in the bed. Sepsis, the steroid course and the missed meals are what move the numbers, and glycaemic control is the supporting act.

1. Patient Baseline & Renal Status

2. Clinical Pathway

Pick a pathway. Only the fields that pathway needs will appear below.

Action Profiles of Common Insulins

Insulin Type Onset Peak Duration
Rapid-Acting (Lispro, Aspart) 10-15 mins1-2 hours3-5 hours
Short-Acting (Regular / Actrapid) 30-60 mins1-2 hours6-8 hours
Intermediate (NPH / Insulatard) 1-2 hours4-8 hours12-18 hours
Long-Acting (Glargine / Lantus) 1-2 hoursPeakless20-24 hours
Ultra-Long (Degludec / Tresiba) 1-2 hoursPeaklessAbove 42 hours
U-500 Regular (Concentrated) 30 mins4-8 hours13-24 hours (behaves as a bolus and an intermediate at once)

1. Timing of Insulin vs. Meals

  • Rapid-Acting (Lispro/Aspart/Glulisine): Give 10 to 15 mins before eating. May be given immediately after eating if oral intake is unpredictable.
  • Short-Acting (Regular): is given 30 to 45 minutes before the meal. Giving it at the time of eating causes a post-prandial spike, before the insulin peaks, followed by delayed hypoglycaemia.
  • Intermediate (NPH) / Premix: Give 30 mins before breakfast and dinner.
  • Basal (Glargine/Degludec): Can be given at any time of day, but must be given at the exact same time every day.

2. Hypoglycaemia, the Somogyi Effect and the Dawn Phenomenon

Hypoglycaemia begets hypoglycaemia unawareness.
Repeated hypoglycaemic events blunt the autonomic warning signs of sweating, palpitations and tremor. Patients may develop severe neuroglycopenia, meaning confusion, seizures or coma, without any prior symptoms. Action: if unawareness is suspected, avoid hypoglycaemia strictly for 2 to 3 weeks by raising the target GRBS, which restores the autonomic warning.

A high morning GRBS has two opposite explanations, and the 3 AM reading separates them.

Somogyi effect, rebound hyperglycaemiaDawn phenomenon
CauseAn undetected nocturnal hypoglycaemic event, usually around 3 AM, which triggers glucagon, cortisol and adrenaline and drives the sugar upThe normal early-morning surge of growth hormone and cortisol, creating insulin resistance
3 AM sugarLowNormal or high
TreatmentDecrease the night NPH or premix dose, or give a bedtime snackIncrease the night NPH or premix, or shift it closer to bedtime
Rule of 15: if the GRBS is below 70 mg/dL, give 15 g of fast-acting carbohydrate: 3 level teaspoons of sugar in water, 150 mL of fruit juice, or one sachet of glucose powder. Recheck the GRBS in exactly 15 minutes. Repeat if still below 70. Once above 70, follow with a complex carbohydrate snack or the next meal, to stop it recurring.

3. The Intravenous Insulin Infusion

Prime the line, or the first hour is wasted. Insulin adsorbs onto the plastic of the giving set. Flush 20 mL of the prepared solution through the tubing and discard it before connecting, otherwise the first 30 to 60 minutes deliver a fraction of the dose set on the pump, and the sugar that does not move gets read as resistance.
  • Preparation used here. 50 units of soluble insulin (Actrapid or Huminsulin R) in 50 mL of 0.9% sodium chloride, giving 1 unit per mL, run through a syringe pump. That is 0.5 mL of a 100 IU/mL vial, or 1.25 mL of a 40 IU/mL vial. Read the strength on the vial before drawing up, and prepare it fresh every 24 hours.
  • Check the potassium before the first unit and every 4 to 6 hours while it runs. Insulin drives potassium into the cell, and an infusion started at a potassium below 3.3 mEq/L will drive it lower.
  • Titrate on the rate of change, not on the reading alone. A glucose of 250 falling by 80 mg/dL an hour and a glucose of 250 sitting still need opposite decisions, and a scale that reads only the current number cannot tell them apart.
  • Hourly capillary glucose until four consecutive readings are in the target band, then every 2 hours.
  • In shock or on vasopressors, use a venous or arterial sample, because peripheral capillary readings are unreliable when the fingertip is underperfused.

4. Insulin in Chronic Kidney Disease and on Dialysis

  • Haemodialysis days are different from other days. Glucose is removed across the membrane while the session runs, meals are often missed for it, and insulin sensitivity improves as uraemia clears. The commonest pattern is hypoglycaemia during the session and for up to 6 hours after it. Reduce the dose that acts across the session, check the glucose at the end of it, and check again 2 hours later.
  • CAPD dialysate is a continuous glucose infusion, and it is easy to forget. A 2 L exchange of 1.5% dextrose instils 30 g, 2.5% instils 50 g, and 4.25% instils 85 g, and roughly 60% is absorbed over a standard dwell. Four exchanges of 2.5% therefore deliver about 120 g of glucose a day, spread flat across it, which favours a basal-heavy or premix regimen over a meal-linked one. Intraperitoneal insulin is no longer recommended, for peritonitis risk and hepatic subcapsular steatosis.
  • HbA1c is unreliable on dialysis and it reads falsely low. Red cell survival is shortened, transfusions dilute the glycated fraction, and erythropoietin increases the young red cell population. A patient with an HbA1c of 6.5% on haemodialysis may be running 250 mg/dL. Judge control from the capillary profile, or from glycated albumin or fructosamine where available, and not from the HbA1c.
Oral AgentAction as eGFR Falls
MetforminHalve the dose below 45. Stop below 30. Hold during any acute illness, contrast study or dehydration.
GlibenclamideAvoid below 60. Renally cleared active metabolites cause prolonged, relapsing hypoglycaemia.
GlimepirideStart at 1 mg and titrate slowly. Avoid below 30.
Gliclazide MRThe preferred Sulfonylurea in renal impairment. Hepatic metabolism, inactive metabolites.
SGLT2 inhibitorsContinue for kidney and cardiac protection down to an eGFR of 20. Below about 45 they lower glucose very little, which is a reason to add something else, not a reason to stop them.
LinagliptinNo dose change at any eGFR, including dialysis. Biliary excretion.
Sitagliptin50 mg below 45, 25 mg below 30 and on dialysis.
PioglitazoneNo renal dose change, but fluid retention limits it in advanced disease and in heart failure.

5. Converting Between Insulins

The unit ratio is the easy half. The timing is the half that causes harm.

  • Regular to a rapid analogue is unit for unit, but the timing moves. Regular must go 30 to 45 minutes before the meal and the analogue 10 to 15 minutes before. Swapping the vial and leaving the timing alone produces a post-meal spike followed by a hypoglycaemic episode before the next meal, and the chart then reads as though the dose is wrong.
  • Glargine to NPH is not one for one. Glargine is peakless and covers 24 hours from a single dose. NPH peaks at 4 to 8 hours and covers 12 to 18, so it must be split, and two overlapping doses stack. Convert at 80% of the glargine dose, split two thirds in the morning and one third at night. Going the other way, from twice-daily NPH to glargine, again use 80% of the NPH total as a single daily dose.
  • Check that the syringe graduation matches the insulin strength. Insulin syringes are sold in both 40 IU/mL and 100 IU/mL graduations, and the vial and the syringe must agree. A U-100 vial drawn up in a 40 IU syringe delivers two and a half times the intended dose. Ask to see both, together, rather than asking what the patient takes.

6. Specialised Inpatient Scenarios

ScenarioWhat to do
Continuous tube feedNPH q6h or basal q24h, each covering about 1 unit per 10 to 15 g of carbohydrate.
Bolus tube feedsRegular insulin subcutaneously 30 min before each feed, at 1 unit per 10 to 15 g.
Cyclic or nocturnal feedsNPH at feed start, then stop or taper it 1 h before the feed ends, or the patient goes low after the feed stops. If a feed is interrupted for more than 2 h, run 10% dextrose intravenously at the prior feed rate until it resumes.
Total parenteral nutritionInsulin goes into the TPN bag, starting at 0.1 U Regular per g of dextrose, so 250 g of dextrose takes 25 U. Add a separate subcutaneous correction scale for breakthrough hyperglycaemia. Never use a separate intravenous insulin infusion alongside TPN. If the TPN stops abruptly, profound hypoglycaemia follows: run 10% dextrose intravenously at the prior TPN rate for 1 to 2 h.
U-500 Regular for severe insulin resistanceIndicated when the TDD exceeds 200 U/day, or 2 U/kg/day. U-500 is 5 times more concentrated than U-100, so it is dosed in volume units: 200 U of U-100 equals 40 volume units of U-500. Dosing errors here are serious. Use only dedicated U-500 syringes or U-500 pens, never standard U-100 syringes. An endocrine opinion is required. Avoid it in the intensive care unit and in critical illness, where a U-100 infusion is used instead.
The postpartum dropWithin 1 to 2 hours of delivery of the placenta, insulin requirements fall by about 50%, as human placental lactogen, cortisol and oestrogen are withdrawn. Continuing pregnancy-era doses is the commonest cause of postpartum ketoacidosis in Type 1 diabetes. Reduce the basal to 50% of the pre-pregnancy TDD immediately. Breastfeeding lowers the requirement by a further 10 to 20%. In gestational diabetes most patients normalise within 24 to 48 h and can stop insulin entirely, with monitoring.
Sick days in Type 1 diabetesNever stop basal insulin during illness, even when the patient is not eating. Fever raises the requirement rather than lowering it: counter-regulatory hormones add 10 to 20% to the daily need. Check ketones if the GRBS is above 250 mg/dL, or if the patient is unwell with a normal GRBS. Correct every 3 to 4 h with Regular insulin. Vomiting with moderate or large ketones means hospital admission. That is impending ketoacidosis.
Active labourMaintain the capillary glucose at 70 to 110 mg/dL throughout labour, using an intravenous insulin infusion with 5% dextrose in normal saline at 100 to 125 mL/h, with capillary glucose hourly. Tight intrapartum control reduces neonatal hypoglycaemia at delivery. For an elective caesarean section, hold all subcutaneous insulin on the morning of surgery and use the intravenous protocol until she is eating.

7. What This Tool Does Not Cover

  • Diabetic ketoacidosis and the hyperosmolar hyperglycaemic state. Those have their own fluid, potassium and fixed-rate insulin protocols. Use the Ketoacidosis and Hyperosmolar State Pathway.
  • Children and adolescents. Every figure here is derived for adults of 18 years and above.
  • Insulin pumps and continuous subcutaneous insulin infusion. A patient admitted on a pump should keep it running under a diabetology opinion, or be converted to a subcutaneous regimen using the conversion pathway with the total daily basal rate as the basal dose.
  • Choosing the oral agent itself for a patient going home. See Outpatient Diabetes Management, and Diabetes Classification where the type is genuinely in doubt.
  • The illness that put the patient in the bed. Glycaemic control is a supporting act. Sepsis, the steroid course and the missed meals are what move the numbers.
Abbreviations: AM (Morning, Ante Meridiem) · BD (Twice Daily) · BMI (Body Mass Index) · CAPD (Continuous Ambulatory Peritoneal Dialysis) · CKD (Chronic Kidney Disease) · CRRT (Continuous Renal Replacement Therapy) · DM (Diabetes Mellitus) · DPP-4 (Dipeptidyl Peptidase-4) · eGFR (Estimated Glomerular Filtration Rate) · GLP-1 (Glucagon-Like Peptide-1) · GRBS (Glucometer Random Blood Sugar) · HbA1c (Glycated Haemoglobin) · HD (Haemodialysis) · HDU (High Dependency Unit) · ICU (Intensive Care Unit) · IU (International Unit) · IV (Intravenous) · MR (Modified Release) · NPH (Neutral Protamine Hagedorn) · OAD (Oral Antidiabetic Drug) · OD (Once Daily) · RRP (Regular-Regular-Premix) · SC (Subcutaneous) · SGLT2 (Sodium-Glucose Cotransporter-2) · TDD (Total Daily Dose) · TPN (Total Parenteral Nutrition) · U-100 (Standard-Strength Insulin, 100 Units per mL) · U-500 (Concentrated Regular Insulin, 500 Units per mL)
References
  1. American Diabetes Association Professional Practice Committee. Standards of Care in Diabetes - 2026. Section 16: Diabetes Care in the Hospital. Diabetes Care. 2026;49(Suppl 1). [Current edition]
  2. Umpierrez GE, Smiley D, Zisman A, et al. Randomised study of basal-bolus insulin therapy in the inpatient management of patients with type 2 diabetes (RABBIT 2 trial). Diabetes Care 2007;30(9):2181-2186.
  3. Goldberg PA, Siegel MD, Sherwin RS, et al. Implementation of a safe and effective insulin infusion protocol in a medical intensive care unit (the Yale protocol). Diabetes Care 2004;27(2):461-467.
  4. Joint British Diabetes Societies for Inpatient Care. The Use of Variable Rate Intravenous Insulin Infusion in Medical Inpatients (JBDS 04). JBDS-IP; revised 2022.
  5. Joint British Diabetes Societies for Inpatient Care. Management of Hyperglycaemia and Steroid (Glucocorticoid) Therapy (JBDS 08). JBDS-IP; revised January 2023. [Supersedes Roberts A, James J, Dhatariya K, et al. Diabet Med 2018;35(8):1011-1017.
  6. McMahon MM, Nystrom E, Braunschweig C, et al. A.S.P.E.N. Clinical Guidelines: Nutrition Support of Adult Patients with Hyperglycemia. JPEN J Parenter Enteral Nutr 2013;37(1):23-36.
  7. Kidney Disease: Improving Global Outcomes (KDIGO) Diabetes Work Group. KDIGO 2022 Clinical Practice Guideline for Diabetes Management in Chronic Kidney Disease. Kidney Int 2022;102(5S):S1-S127.
  8. Research Society for the Study of Diabetes in India. RSSDI Clinical Practice Recommendations for the Management of Type 2 Diabetes Mellitus. Int J Diabetes Dev Ctries 2022;42(Suppl 1):1-143.
  9. Gangopadhyay KK, Bantwal G, Talwalkar PG, Muruganathan A, Das AK. Consensus evidence-based guidelines for in-patient management of hyperglycaemia in non-critical care setting as per Indian clinical practice. J Assoc Physicians India. 2014;62(7 Suppl):6-15. PMID 25668932.
  10. American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 201: Pregestational Diabetes Mellitus. Obstet Gynecol 2018;132(6):e228-e248.
  11. Joint British Diabetes Societies for Inpatient Care. The Hospital Management of Hypoglycaemia in Adults with Diabetes Mellitus (JBDS 01). JBDS-IP; revised 2023.
  12. Lane WS, Cochran EK, Jackson JA, et al. High-dose insulin therapy: Is it time for U-500 insulin? Endocr Pract 2009;15(1):71-79.
How to Cite This Tool

AMA Style:
Umakanth S. Inpatient Basal-Bolus Insulin Protocol. MEDiscuss. Published 2026. Accessed .

Vancouver Style:
Umakanth S. Inpatient Basal-Bolus Insulin Protocol [Internet]. MEDiscuss.org; 2026 [cited ]. Available from:

Disclaimer and scope
Disclaimer: This decision-support system is written for healthcare professionals. It does not substitute clinical judgment, and the treating physician retains absolute responsibility for every diagnostic, dosing and therapeutic decision. The algorithms are built on the evidence as it stands, and the evidence moves. Verify the output against your current institutional protocol, and against the patient in front of you.
© 2026 MEDiscuss.org. All rights reserved. This CDSS Module was designed and developed by Dr Shashikiran Umakanth from the published evidence. Provided free of charge for clinical use. Unauthorised reproduction or redistribution is strictly prohibited. Keep this system on your phone's home screen
Category Therapeutic & Management PathwaysProtocol
Specialties Internal Medicine, Endocrinology
Written and maintained by Dr Shashikiran Umakanth.
Last revised: 24 August 2026
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Further Reading on MEDiscuss
Daily insulin titration: the crossover methodThe method behind the titration table, including the TDD per kg safety check