Intraop Glucose — Insulin Protocols, DKA, Pump Management

The tighter 80-110 mg/dL target was tested in NICE-SUGAR (NEJM 2009, 6,104 ICU patients) and produced MORE deaths than 140-180, largely from severe hypoglycemia (<40 mg/dL in 6.8% vs 0.5%).

Hyperglycemia >200 mg/dL is independently associated with surgical site infection (especially cardiac, colorectal, joint replacement), delayed wound healing, and worse stroke outcomes.

Below 140 risks unrecognized hypoglycemia in an anesthetized patient — the brain can't signal.

Check q1h with a point-of-care meter on long cases or any insulin infusion.

Bolus 0.1 U/kg only for glucose >250 mg/dL with adequate K.

Rule of thumb: divide glucose by 100 for starting rate (e.g., 240 → 2.4 U/hr).

Long-acting basal (glargine, detemir, degludec) is given SC and continues to act for 12-24+ hours — do NOT stop the home basal dose entirely; reduce to 50-80% the night before.

Stop short-acting agents (lispro, aspart) the morning of surgery.

Hold metformin, SGLT2 inhibitors (3-day hold — DKA risk even at normal glucose), and sulfonylureas day-of.

DKA presenting urgently in the OR (often appendicitis or sepsis triggering): FLUID FIRST — 1-2 L NS in the first hour, then 0.45% NS at 250-500 mL/hr; the deficit is typically 5-10 L.

Check potassium BEFORE starting insulin: if K <3.3, hold insulin and replete K first (insulin drives K intracellular → can precipitate arrest).

When K is 3.3-5.3, give insulin 0.1 U/kg/hr infusion (no bolus needed) + KCl 20-40 mEq/L in fluids.

Bicarbonate only if pH <6.9 (controversial; can worsen intracellular acidosis).

When glucose drops to ~250 mg/dL, add D5 to the IV fluids — keep insulin running until the anion gap closes; bridge to SC long-acting insulin 1-2 hr BEFORE stopping the gtt.

Hyperosmolar hyperglycemic state (HHS) is the T2DM cousin of DKA: glucose often >600 mg/dL, osmolality >320, minimal ketones, pH >7.3, profound dehydration (often 8-12 L deficit), altered mental status from hyperosmolarity.

Correction is SLOWER than DKA — too-rapid sodium/osmolality correction precipitates cerebral edema.

Drop osmolality no faster than 3 mOsm/kg/hr; drop glucose no faster than 50-75 mg/dL/hr.

Insulin rates are lower (0.05 U/kg/hr); fluid + potassium are the main therapies.

Mortality 10-20%, higher than DKA, because patients are older with more comorbidities.

Periop plan: continue the pump at its basal rate for short cases (<2 hr), supplement IV regular insulin boluses for hyperglycemia.

For long, complex, or high-cautery cases — switch to IV insulin gtt and stop the pump.

MRI: REMOVE the pump (ferromagnetic components + electronics) before entry to Zone 4. Ensure the infusion site is well away from the surgical field, cautery pad, and prep solution.

CGM sensors should also be removed for MRI; for OR cases they can stay if the site is protected, but accuracy drops with vasopressors and hypothermia — confirm with fingerstick before any insulin dose.

Communicate the plan with endocrinology preoperatively.

Clinically significant in diabetics — anticipate and check.

Chronic steroid users need stress-dose coverage for major surgery: hydrocortisone 50-100 mg IV at induction then 50 mg q8h × 24-48 hr for moderate-major surgery (less for minor procedures per Salem/Liu protocol).

Skip stress-dose if patient is on <5 mg prednisone/day or has been off steroids >3 months.