Clinical Trial: Post-Operative Water Load Following Transsphenoidal Pituitary Surgery

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Post-Operative Water Load Following Transsphenoidal Pituitary Surgery

Brief Summary: 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.

Detailed Summary: 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.
Sponsor: St. Joseph's Hospital and Medical Center, Phoenix

Current Primary Outcome:

• 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)
• 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)
• 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)
• 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)

Original Primary Outcome: Same as current

Current Secondary Outcome: Post-Discharge Response [ Time Frame: Post-Operative Day 2-7 ]

Original Secondary Outcome: Same as current

Information By: St. Joseph's Hospital and Medical Center, Phoenix

Dates:
Date Received: March 23, 2016
Date Started: April 2016
Date Completion: January 2018
Last Updated: October 10, 2016
Last Verified: October 2016