Furosemide vs Placebo for Brain Relaxation

Overview

Increased brain bulk may be problematic during brain surgery for tumors because it may limit surgical exposure and access to the surgical site. Mannitol, an osmotic diuretic, is commonly given to alleviate brain bulk, and sometimes furosemide in a small dose is added if mannitol alone is insufficient. It is unclear if adding this furosemide truly helps to diminish brain bulk, and it is possible that furosemide may cause too much diuresis, leading to dehydration and its side effects (e.g., low blood pressure). Our purpose is to investigate what the effects of furosemide are in the setting of brain surgery for tumors, specifically with regards to decreasing brain bulk and/or causing dehydration. Study Hypothesis: The addition of furosemide to mannitol will result in improved brain relaxation in human subjects undergoing craniotomy for brain tumor resection than that seen with mannitol alone. However, the combination of mannitol and furosemide will also lead to more significant intravascular volume depletion than that seen with mannitol alone.

Full Title of Study: “The Effect of Furosemide Versus Placebo on Brain Relaxation and Incidence of Significant Intravascular Volume Depletion in Human Subjects Receiving Mannitol”

Study Type

• Study Type: Interventional
• Study Design
  • Allocation: Randomized
  • Intervention Model: Parallel Assignment
  • Primary Purpose: Treatment
  • Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
• Study Primary Completion Date: March 2012

Detailed Description

Rating of brain relaxation will be on a 4-point scale: 0 = brain very relaxed under dura, acceptable 1. = brain adequately relaxed under dura, acceptable 2. = brain slightly tense under dura, acceptable 3. = brain very tense under bulging dura, unacceptable

Interventions

• Drug: Furosemide
  • Furosemide 0.3 mg/kg
• Drug: Placebo
  • Placebo (up to 5mL)

Arms, Groups and Cohorts

• Active Comparator: Furosemide
  • Furosemide 0.3 mg/kg
• Placebo Comparator: Placebo
  • Up to 5 mL saline

Clinical Trial Outcome Measures

Primary Measures

• Acceptable vs. Unacceptable Brain Relaxation at Dural Opening
  • Time Frame: just prior to dural opening for each subject
  • Rating of brain relaxation will be on a 4-point scale: 0 = brain very relaxed under dura, acceptable = brain adequately relaxed under dura, acceptable = brain slightly tense under dura, acceptable = brain very tense under bulging dura, unacceptable

Participating in This Clinical Trial

Inclusion Criteria

Inclusion criteria include:

• ASA PS I-III – Age 18 or older – Presenting for elective resection of primary or metastatic supratentorial brain tumor(s) Exclusion Criteria:

• • ASA PS IV or V – Age less than 18 – Emergency surgery due to severely elevated ICP/impending brainstem herniation – Concurrent use of diuretics for any indication – Infratentorial/posterior fossa/cerebellar tumor resection – Moderate/severe cardiac disease with limitation in contractility as measured by preoperative echocardiogram (EF < 30%) – Severe pulmonary hypertension as measured and/or observed by preoperative studies – Preoperative use of steroids (within 6 months, including those on standing doses) – Pregnancy

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

• Lead Sponsor
  • Northwestern University
• Provider of Information About this Clinical Study
  • Principal Investigator: John Bebawy, Assistant Professor of Anesthesiology & Neurological Surgery – Northwestern University
• Overall Official(s)
  • John F Bebawy, MD, Principal Investigator, Northwestern University
  • Dhanesh K Gupta, MD, Study Director, Northwestern University

References

Thenuwara K, Todd MM, Brian JE Jr. Effect of mannitol and furosemide on plasma osmolality and brain water. Anesthesiology. 2002 Feb;96(2):416-21. doi: 10.1097/00000542-200202000-00029.

Todd MM, Cutkomp J, Brian JE. Influence of mannitol and furosemide, alone and in combination, on brain water content after fluid percussion injury. Anesthesiology. 2006 Dec;105(6):1176-81. doi: 10.1097/00000542-200612000-00017.

Rudehill A, Lagerkranser M, Lindquist C, Gordon E. Effects of mannitol on blood volume and central hemodynamics in patients undergoing cerebral aneurysm surgery. Anesth Analg. 1983 Oct;62(10):875-80.

Todd MM, Warner DS, Sokoll MD, Maktabi MA, Hindman BJ, Scamman FL, Kirschner J. A prospective, comparative trial of three anesthetics for elective supratentorial craniotomy. Propofol/fentanyl, isoflurane/nitrous oxide, and fentanyl/nitrous oxide. Anesthesiology. 1993 Jun;78(6):1005-20. doi: 10.1097/00000542-199306000-00002.

Rozet I, Tontisirin N, Muangman S, Vavilala MS, Souter MJ, Lee LA, Kincaid MS, Britz GW, Lam AM. Effect of equiosmolar solutions of mannitol versus hypertonic saline on intraoperative brain relaxation and electrolyte balance. Anesthesiology. 2007 Nov;107(5):697-704. doi: 10.1097/01.anes.0000286980.92759.94.