What are the recommendations for intravenous (IV) fluids in spine surgery?

Intravenous Fluid Management in Spine Surgery

General Recommendations

For spine surgery, balanced crystalloid solutions (such as Ringer's Lactate or Plasmalyte) should be used as the primary intravenous fluid rather than 0.9% saline to minimize the risk of hyperchloremic metabolic acidosis and adverse renal events. 1

Key principles for IV fluid management in spine surgery include:

• Balanced crystalloids are preferred over 0.9% saline for most spine surgery patients due to their lower risk of hyperchloremic metabolic acidosis and adverse renal outcomes 1
• A near-zero fluid balance approach is recommended during spine surgery to minimize complications 2
• Crystalloids should be used as the primary fluid for intraoperative volume replacement rather than colloids 2
• Intraoperative fluid administration rates of 1-2 ml/kg/h are recommended to minimize the risk of postoperative complications 1

Special Considerations for Spine Surgery

Fluid Type Selection

• Balanced crystalloid solutions (Ringer's Lactate, Plasmalyte) should be the first choice for most spine surgery patients 1, 3
• 0.9% saline should be avoided for large volume replacement due to the risk of hyperchloremic metabolic acidosis 1, 4
• Hypotonic solutions should be strictly avoided in spine surgery patients due to the risk of cerebral edema 2
• Synthetic colloids (hydroxyethyl starch, gelatin) are not recommended due to increased risk of renal failure and lack of outcome benefit 2, 1
• Albumin is not recommended for routine use in spine surgery, particularly in patients with traumatic brain injury 2

Volume Management

• Maintain a near-zero fluid balance during spine surgery to minimize complications 2
• Avoid excessive fluid administration as it can lead to organ dysfunction, pulmonary complications, and poor wound healing 1
• Monitor hemoglobin or hematocrit values periodically during surgery in high-risk patients experiencing substantial blood loss 2
• Use transfusions of blood products as deemed appropriate based on hemoglobin levels and clinical status 2

Monitoring and Administration

• Oliguria should not automatically trigger fluid therapy as low urine output is a normal physiological response during surgery 2
• Intraoperative fluid administration should be guided by objective measures of hypovolemia rather than fixed formulas 1
• Adrenergic agonists (vasopressors) may be used on a case-by-case basis when necessary to correct hypotension rather than administering excessive fluids 2
• Discontinue intravenous fluids as early as possible postoperatively and transition to oral intake 2, 1

Specific Clinical Scenarios

Spine Surgery with Significant Blood Loss

• For procedures with anticipated significant blood loss (>800 mL), monitor hemoglobin/hematocrit values periodically 2
• Use blood transfusions as appropriate rather than excessive crystalloid administration 2
• Maintain adequate intravascular volume without causing fluid overload 1

Spine Surgery in Patients with Traumatic Brain Injury

• 0.9% saline is recommended as first-line fluid therapy in patients with traumatic brain injury 2
• Avoid hypotonic solutions in neurosurgical patients 2
• Albumin is contraindicated in patients with traumatic brain injury 2
• Maintain euvolemia to ensure adequate cerebral perfusion while avoiding cerebral edema 2

Prolonged Prone Position Spine Surgery

• Brimonidine eye drops may help reduce intraocular pressure during prolonged prone positioning 5
• Maintaining adequate blood pressure might play a more important role than fluid type in preventing increased intraocular pressure 5
• Goal-directed fluid therapy should be considered for complex spine procedures with prolonged operative times 1

Potential Complications and Prevention

• Hyperchloremic metabolic acidosis: Avoid large volumes of 0.9% saline and prefer balanced solutions 4, 3
• Postoperative respiratory acidosis: Monitor for this complication particularly with large volume infusion of lactated Ringer's solution 4
• Cerebral edema: Avoid hypotonic solutions in spine surgery patients, particularly those with traumatic brain injury 2
• Renal dysfunction: Maintain adequate intravascular volume without excessive fluid administration 2, 1
• Increased intraocular pressure: Consider brimonidine eye drops for prolonged prone positioning and maintain adequate blood pressure 5

By following these evidence-based recommendations for IV fluid management in spine surgery, clinicians can optimize patient outcomes while minimizing complications.