Tresiba Dosing and Carb Ratio in Post-Operative Type 1 Diabetes with Ketosis
Hold Tresiba entirely and continue the insulin drip until ketones clear and the patient is eating consistently, then restart Tresiba at 50% of the pre-operative dose (6 units daily) with a starting carb ratio of 1:15.
Immediate Management Priority
Continue the insulin drip until ketosis resolves completely. This patient has elevated ketones (1.43 mmol/L) with an anion gap of 13 and bicarbonate of 22, indicating mild ketosis that requires ongoing IV insulin therapy 1. During acute illness and post-operative stress in type 1 diabetes, insulin requirements continue and often increase due to counter-regulatory hormones 1.
Critical Action Steps:
- Do not give any basal insulin while on insulin drip - the drip provides continuous basal coverage and adding Tresiba risks dangerous overlap given its 42-hour duration of action 2, 3
- Monitor ketones every 4-6 hours until they normalize (<0.6 mmol/L) 1
- Continue D5 at 100 mL/hr to provide 150-200g carbohydrate daily (24g/hr × 24 = 576g dextrose = ~240g carbohydrate absorbed), which prevents starvation ketosis during NPO status 1
- Check blood glucose every 1-2 hours while on insulin drip 4, 2
Transitioning Off Insulin Drip
Only transition when ALL of the following are met:
- Ketones <0.6 mmol/L 1
- Patient tolerating oral intake consistently 2
- Insulin drip rate ≤0.5 units/hour 2
- Blood glucose stable at 140-180 mg/dL 2
Calculating Tresiba Dose:
The patient required 3-12 units/hour on the drip (average ~7.5 units/hour = 180 units/24 hours), which is dramatically higher than their pre-operative 12 units daily due to surgical stress 2. However, do not base the new Tresiba dose on drip requirements - this leads to severe hypoglycemia once stress resolves 2.
Start Tresiba at 50% of pre-operative dose = 6 units once daily 2. This accounts for:
- Ongoing post-operative insulin resistance (first 3-5 days) 4, 2
- Reduced oral intake initially 1
- Safety margin to prevent hypoglycemia as stress resolves 2
Timing: Give Tresiba at the same time daily, ideally evening, and overlap with insulin drip for 2 hours before stopping the drip 2.
Carbohydrate Ratio Calculation
Start with 1:15 ratio (1 unit rapid-acting insulin per 15g carbohydrate) 1.
Rationale:
- Pre-operative weight 84 kg suggests total daily insulin ~0.5-0.6 units/kg = 42-50 units/day for type 1 diabetes 4
- With 6 units basal, this leaves ~36-44 units for boluses
- Assuming 150-200g carbohydrate daily post-operatively = ~50g per meal × 3 meals 1
- 50g ÷ 3 units = 1:17 ratio, rounded to 1:15 for simplicity
Adjust based on 2-hour post-meal glucose:
Critical Pitfalls to Avoid
Never stop the insulin drip abruptly without overlapping basal insulin - this causes rebound hyperglycemia and worsening ketosis in type 1 diabetes 2. However, in this case with persistent ketones, the drip must continue until ketosis clears regardless of timing 1.
Do not use pre-operative Tresiba dose (12 units) immediately - the patient is not eating normally and this will cause severe hypoglycemia 4, 2. The 50% reduction (6 units) provides safety while maintaining basal coverage 2.
Do not rely on sliding scale insulin alone - type 1 diabetes requires basal-bolus therapy with carb counting, not reactive corrections 1, 2.
Monitor for recurrent ketosis - post-operative stress, poor oral intake, and recent insulin drip use create ongoing risk for ketosis even after initial resolution 1, 5. Check ketones daily for the first 3-5 post-operative days 1.
Ongoing Adjustment
Increase Tresiba by 2 units every 3 days if fasting glucose consistently >140 mg/dL once oral intake is stable 4, 2. Target return to pre-operative dose (12 units) by post-operative day 7-10 as surgical stress resolves 4, 2.
Reassess carb ratio weekly based on post-meal glucose patterns, aiming for 2-hour post-meal glucose 140-180 mg/dL 1, 2.