What intra‑operative fluid regimen should be used for a diabetic patient undergoing surgery?

Intraoperative Fluid Management for Diabetic Patients Undergoing TAH-BSO

Use balanced crystalloid solutions (Ringer's lactate or Plasmalyte) at 2-6 mL/kg/h, aiming for a slightly positive fluid balance of 1-2 liters by the end of surgery, while maintaining blood glucose between 90-180 mg/dL (5-10 mmol/L) with IV insulin infusion plus IV glucose (4 g/h) and electrolytes. 1, 2

Fluid Type Selection

Balanced crystalloids are the preferred choice over 0.9% normal saline for diabetic surgical patients. 1, 2

• All solutes may be used in the perioperative period for diabetic patients, including Ringer's lactate. 1
• Balanced crystalloids (Hartmann's or Ringer's lactate, Plasmalyte) should be preferred over 0.9% saline to avoid hyperchloremic acidosis, renal vasoconstriction, and acute kidney injury. 1, 2
• Normal saline causes hyperchloremic metabolic acidosis and reduced renal cortical perfusion when used excessively. 1
• Avoid dextrose-containing maintenance fluids (such as D5NS) as they cause significant hyperglycaemia even in non-diabetic patients—a 500 mL infusion of 5% dextrose in normal saline elevated plasma glucose to 11.1 mmol/L in 72% of non-diabetic patients. 3

Fluid Volume Strategy

Target a near-zero to mildly positive fluid balance (+1-2 L) by the end of surgery. 1, 2

• Administer balanced crystalloids at 2-6 mL/kg/h during surgery (for a 70 kg patient: 140-420 mL/h). 2
• Excessive fluid overload (>2.5 kg perioperative weight gain) increases complications including wound infections, cardiac complications, delayed bowel function, and anastomotic leaks. 1, 2
• Both insufficient fluid (causing hypovolemia) and excessive fluid (causing overload) worsen outcomes and prolong hospital stay. 1, 2
• Use vasopressors rather than excessive fluids to manage epidural-induced hypotension in normovolemic patients. 1

Glucose Management During Fluid Administration

Administer IV insulin continuously with concurrent IV glucose (equivalent of 4 g/h) and electrolytes throughout the intraoperative period. 1

• Target blood glucose between 90-180 mg/dL (5-10 mmol/L), with therapeutic adjustment if glucose exceeds 180 mg/dL (10 mmol/L). 1
• Avoid tight glycemic control (80-120 mg/dL) as this increases severe hypoglycemia risk and possibly mortality without improving outcomes. 1
• Moderate glycemic control (140-180 mg/dL or 7.7-10 mmol/L) provides the best balance of reduced morbidity/mortality without hypoglycemia risk. 1
• Monitor blood glucose every 1-2 hours using arterial or venous blood samples (not capillary fingerstick, which overestimates values especially with vasoconstriction). 1
• Monitor potassium every 4 hours to avoid insulin-induced hypokalemia. 1

Hemodynamic Monitoring Considerations

Consider goal-directed fluid therapy with stroke volume monitoring in high-risk diabetic patients or those with significant comorbidities. 2

• Trans-oesophageal Doppler (TOD) or other flow-guided monitoring reduces complications and length of stay when used to optimize cardiac output with fluid boluses. 1
• In diabetic patients with heart failure or renal disease, use the lower end of the fluid range (2-4 mL/kg/h) and implement hemodynamic monitoring. 2
• Treat hypotension with vasopressors rather than fluid boluses when stroke volume variation is <10% or fluid responsiveness is absent. 2

Critical Pitfalls to Avoid

• Never use dextrose-containing crystalloids as maintenance fluids intraoperatively, as they cause hyperglycemia even in non-diabetics and worsen outcomes in diabetics. 3
• Never rely on capillary glucose readings alone—a fingerstick value of 70 mg/dL (3.8 mmol/L) should be considered hypoglycemia and verified with laboratory measurement. 1
• Never administer IV insulin without concurrent IV glucose (4 g/h) and electrolytes, as this increases hypoglycemia risk. 1
• Never use 0.9% saline as the primary fluid when balanced crystalloids are available, as saline causes hyperchloremic acidosis and renal dysfunction. 1, 2
• Never aim for "zero balance" fluid strategy, as this increases acute kidney injury risk compared to a moderately positive balance. 2