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Completed

NCT Number: NCT05233566

Ketamine for Postoperative Avoidance of Depressive Symptoms: The K-PASS Feasibility Trial

This protocol describes a feasibility trial that will evaluate the feasibility of conducting a full-scale phase 3 trial testing the hypothesis that a postoperative sustained, low-dose ketamine infusion can prevent postoperative depressive symptoms when administered to a targeted population of neurosurgical patients with a history of depression.

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Key information

Conditions

Postoperative Depression

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

Washington University School of Medicine

St Louis, Missouri, 63110, United States

About this study

This protocol describes a feasibility trial that will evaluate the feasibility of conducting a full-scale phase 3 trial. Both the feasibility trial and the full-scale trial will follow a randomized, placebo-controlled, double-blinded, parallel design. The trial will follow a superiority design. This trial will take place at a single site (Washington University in St. Louis School of Medicine/Barnes-Jewish Hospital).

Following extubation, patients will be randomized to the intervention (ketamine group) or to control (control group). Patients in the ketamine group will receive a bolus of ketamine 0.5 mg/kg intravenously over 10 minutes, followed by an infusion at 0.3 mg/kg/h for an additional 2 hours 50 minutes. Patients in the control group will receive an equal volume of normal saline. Patients, research staff performing assessments, and research staff performing data analysis will be blinded to treatment allocation.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Able to provide written, informed consent
  • Aged 18 or older
  • Scheduled for non-ambulatory surgery scheduled to last at least 2 hours at Barnes-Jewish Hospital
  • Past medical history of depression, defined as one or more of the following criteria
  • Previous diagnosis by a psychiatrist or primary care physician in an outpatient or inpatient setting, by patient report or chart documentation
  • Prescription of an oral antidepressant by a psychiatrist or primary care physician for a mood disorder

Exclusion criteria

  • Bipolar depression
  • Concurrent use of a medication contraindicated with ketamine
  • Emergent surgery
  • Known or suspected elevation in intracranial pressure
  • Current subarachnoid hemorrhage
  • Carotid endarterectomy or arteriovenous malformation repair
  • Allergy to ketamine
  • Any condition in which a significant elevation of blood pressure would constitute a serious hazard (e.g., aortic dissection, pheochromocytoma)
  • Known history of dementia
  • Pregnancy or lactation
  • Inability to converse in English
  • Concurrent enrollment in another interventional trial

Treatment and study plan

ketamine

Drug

NMDA antagonist

Other names: Ketalar

normal saline

Drug

IV fluid acting as a placebo

Primary outcomes

  1. Fraction of Approached Patients Who Enroll and Are Randomized

    Time frame: 3 days after surgery

    The numerator will include all patients who are randomized to receive either ketamine or placebo.

    The denominator will include all patients who are approached by the research team to evaluated eligibility and offer consent.

  2. Fraction of Randomized Patients Who Complete the Study Infusion

    Time frame: 3 days after surgery

    The numerator will include all participants who received the entire study medication infusion as planned.

    The denominator will include all participants who are randomized to receive either ketamine or the placebo.

  3. Fraction of Randomized Patients With Depression Rating Scale Scores at All Specified Time Points

    Time frame: 14 days after the intervention

    Depression will be measured using the Montgomery-Asberg Depression Rating Scale (MADRS) at pre-operative baseline and on post-infusion days 1, 2, 4, 7, and 14. MADRS scores range 0 to 60, with higher scores representing worse depression.

    The numerator will include all patients with MADRS scores documented at all 6 time points.

    The denominator will include all participants who are randomized to receive either ketamine or the placebo.

Secondary outcomes

  1. Depressive Symptoms on Day 4

    Time frame: 4 days after the intervention

    Depression will be measured using the Montgomery-Asberg Depression Rating Scale (MADRS) at pre-operative baseline and on post-infusion days 1, 2, 4, 7, and 14. MADRS scores range 0 to 60, with higher scores representing worse depression.

    The distribution of MADRS scores in the population will be assessed for normality using visual analysis of histograms and using the Kolmogorov-Smirnoff test. If the MADRS scores are normally distributed, then the mean scores in the two groups on post-infusion day 4 will be compared using linear regression, adjusting for preoperative score. If the MADRS scores are not normally distributed, then the median delta scores in the two groups will be compared using median regression, adjusting for preoperative score.

    Participants with missing MADRS scores at either time point (preoperative baseline or post-infusion day 4) will be excluded.

  2. Delta Sleep Ratio on Night 1 Following Study Medication

    Time frame: 2 days after intervention

    Electroencephalograms (EEG) will be captured during sleep using the Dreem headband (DREEM, Rhythm, New York, NY), a consumer-grade wireless device using dry electrodes. Sleep stages (e.g., non-rapid eye movement [NREM], rapid eye movement, wakefulness) will be detected using the Dreem headband's built-in automated sleep scoring algorithm. During each time epoch, slow wave activity will be defined as the EEG power in the range 1-4 Hz. The delta sleep ratio (DSR) will be defined as the ratio of slow wave activity during the first NREM epoch to slow wave activity during the second NREM epoch.

    Because it is a ratio, the DSR is a dimensionless number. In normal sleep, slow wave activity is greatest at the beginning of the night and decreases throughout the night. Therefore, higher DSR values reflect a more normal sleep architecture.

Sponsors and collaborators

Lead sponsor

Washington University School of Medicine

Other

Registry information

Acronym: K-PASS

Important dates

Study start
2022
Primary completion
2023
Study completion
2023
First posted
Feb 10, 2022
Registry last updated
Feb 12, 2026

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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