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Completed

NCT Number: NCT02727686

Post-Operative Water Load Following Transsphenoidal Pituitary Surgery

Delayed post-operative hyponatremia occurs in 5-20% of patients following pituitary surgery and typically occurs on post-operative day 5-10.This decline in sodium can occur rapidly and have serious consequences such as altered mental status, seizures, coma, and even death. Despite significant research into patient demographics and risk factors, the investigators have not been able to predict which patients will suffer from delayed post-operative hyponatremia to date. At the Barrow Neurological Institute, physicians currently utilize an outpatient screening protocol to monitor patients' sodium levels after surgery, but this has yet to be effective for reducing readmissions following pituitary surgery. The etiology of delayed post-operative hyponatremia has been linked to water and sodium dysregulation in the post-operative period. It has been shown that post-operative day 1-2 sodium levels are statistically lower in patients who develop delayed hyponatremia, however, the numerical differences are not large enough to guide clinical management. The investigators propose that a water load on post-operative day 1 may expose underlying sodium/water dysregulation in the early post-operative period. This would improve physicians' understanding of the pathophysiology of post-operative hyponatremia, and it may help to serve as a screening tool for these patients in the future.

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Key information

Conditions

Hyponatremia Brain Diseases Brain Neoplasms Central Nervous System Diseases Central Nervous System Neoplasms Endocrine Gland Neoplasms Endocrine System Diseases Hypothalamic Diseases Hypothalamic Neoplasms Metabolic Diseases Neoplasms Neoplasms by Site Nervous System Diseases Nervous System Neoplasms Nutritional and Metabolic Diseases Pituitary Adenoma Pituitary Diseases Pituitary Neoplasms Supratentorial Neoplasms Water-Electrolyte Imbalance

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Barrow Brain and Spine

Phoenix, Arizona, 85013, United States

About this study

Current standards are for screening of all post-operative transsphenoidal pituitary patients for sodium abnormalities in the POD(post-operative day)7-14 window. At the Barrow Neurological Institute, physicians have instituted a universal screening protocol for all post-operative patients wherein all patients have a serum sodium level drawn on POD5-7 and attempts are made to manage mild to moderate hyponatremia on an outpatient basis.This screening protocol has effectively identified delayed post-operative hyponatremia, however, it has yet to reduce readmissions for hyponatremia in these patients. The researchers propose that implementing a water load test on POD1 may facilitate outpatient screening in three ways: 1) The water load may identify a subset of patients who have appropriate water and sodium regulation after surgery and do not require close monitoring of outpatient sodium levels. 2) The water load may identify a subset of patients who are at risk for delayed hyponatremia and would benefit from strict counseling and closer outpatient monitoring. 3) The water load may identify a subset of patients with a moderate to severe reduction in serum sodium in response to the water load, and these patients may benefit from further monitoring in the hospital prior to discharge. If any of these scenarios hold true, this may change the way physicians monitor and treat patients following transsphenoidal surgery in the future. Furthermore, this protocol could be readily expanded to other neurosurgery practices and could facilitate care for future patients undergoing transsphenoidal pituitary surgery.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 18-80 years of age
  • Functioning or non-functioning pituitary adenoma
  • Sodium level 135-145 prior to surgery

Exclusion criteria

  • Enrolled in a separate pituitary research study
  • Unable to provide his/her own consent
  • Unable to take PO water
  • Renal insufficiency
  • Require maintenance corticosteroids pre-operatively
  • TSH secreting tumor
  • Patients who the treating surgeon deems a poor candidate for the water challenge
  • Prisoners
  • Pregnant women

Treatment and study plan

Water Load (WL) Post-Operative Day 1

Other

Patient will have normonatremic 0600 hr sodium level (Serum Sodium = 135 - 145 mmol/L), ability to safely take water by mouth, and cleared to continue by treating surgeon. WL will be calculated (20 mL/kg body weight) and supplied at the bedside. Vasopressin level will be determined. Patient will have 30 minutes to consume WL, or will be excluded. Included patients will have data collected as follows: 1 hour - serum sodium, urine output; 2 hour - serum sodium, urine output, vasopressin level; 6 hours - serum sodium, urine output.

Primary outcomes

  1. POD1 Response Serum Sodium

    Time frame: Post-Operative Day 1

    Evaluate patients' responses to water load on the morning of post-operative day 1: serum sodium (normal range 135-145 mmol/L)

  2. POD1 Response Serum Osmolality

    Time frame: Post-Operative Day 1

    Evaluate patients' responses to water load on the morning of post-operative day 1: serum osmolality (normal range 275-300 mOsm/kg)

  3. POD1 Response Urine Output

    Time frame: Post-Operative Day 1

    Evaluate patients' responses to water load on the morning of post-operative day 1: urine output (normal range > 0.5 ml/kg/hr)

  4. POD1 Response Vasopressin

    Time frame: Post-Operative Day 1

    Evaluate patients' responses to water load on the morning of post-operative day 1: vasopressin level (normal range 0.0 - 6.9 pg/ml)

Secondary outcomes

  1. Post-Discharge Response

    Time frame: Post-Operative Day 2-7

    Follow patients' serum sodium levels after discharge from the hospital and assess for any correlation in water load response and outpatient sodium levels. This is not done with a mathematical calculation but by observation of lab results. Hypothetically, normal water load response (serum sodium =135-145) will equate to normal outpatient sodium levels (135-145). Likewise, an abnormal water load response (sodium < 135 or >145) will equate to possible abnormal outpatient sodium levels (< 135, >145).

Sponsors and collaborators

Lead sponsor

St. Joseph's Hospital and Medical Center, Phoenix

Other

Collaborators

  • Barrow Brain and Spine
  • Barrow Neurological Institute

Registry information

Important dates

Study start
2016
Primary completion
2018
Study completion
2018
First posted
Apr 5, 2016
Registry last updated
Nov 25, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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