Management of Mild Hyponatremia in Hip Fracture Patients

Immediate Assessment and Workup

The American College of Surgeons recommends that hyponatremia is common (17%) in hip fracture patients on admission and typically indicates infection or medication effects (particularly thiazide diuretics) 1
The American Society of Anesthesiologists suggests assessing volume status clinically to categorize as hypovolemic, euvolemic, or hypervolemic hyponatremia—this guides treatment, and checking for signs of infection (chest, urine) as leukocytosis may indicate infection, which commonly causes hyponatremia 1
The American Geriatrics Society recommends reviewing medications immediately, especially thiazide diuretics, which are a frequent culprit, and obtaining urea and electrolytes to assess for other abnormalities (hypokalaemia, hyperkalaemia) 1

The American College of Cardiology suggests that if hypovolemic: administer normal saline IV to restore volume—many patients are hypovolaemic before surgery, although the strength of evidence is moderate 2
The Neurosurgery society recommends that if euvolemic (SIADH suspected): implement fluid restriction to 1L/day, but do NOT use aggressive fluid restriction in hip fracture patients as this increases cerebral infarction risk, with high strength of evidence 3
The American Society of Anesthesiologists recommends prescribing pre-operative IV fluids routinely as cardiac output-guided fluid administration reduces hospital stay, with moderate strength of evidence 2

The American College of Clinical Pharmacy recommends that if medication-induced (thiazides): discontinue the offending agent immediately, with high strength of evidence 1
The Infectious Diseases Society of America suggests that if infection-related: treat infection promptly with antibiotics, supplemental oxygen, and IV fluids, with moderate strength of evidence 4
The Endocrine Society recommends considering fludrocortisone 0.1 mg three times daily if cerebral salt wasting is suspected (reduces urinary sodium excretion), with low strength of evidence 3

The American Academy of Orthopaedic Surgeons recommends that surgery should proceed within 48 hours regardless of mild hyponatremia (Na 129 mmol/L), as delaying surgery beyond 48 hours significantly increases mortality, pneumonia, pressure sores, and thromboembolic complications, with high strength of evidence 2
The American Society of Anesthesiologists suggests that regional anesthesia (spinal or epidural) is strongly preferred as it reduces sympathetic hyperactivity, allows early mobilization, and improves outcomes, with moderate strength of evidence 2

The American College of Surgeons recommends maintaining adequate hydration with goal-directed fluid therapy using cardiac output monitoring, with moderate strength of evidence 2
The American Geriatrics Society suggests that early mobilization is critical despite hyponatremia—improves outcomes and reduces complications, with high strength of evidence 2
The Neurosurgery society recommends that do not aggressively fluid-restrict hip fracture patients with hyponatremia—this increases cerebral infarction risk, with high strength of evidence 3