Ketamine Infusions Administered Solely by Psychiatric Staff

Abstract

Even though intravenous ketamine is not an FDA-approved depression treatment, multiple studies have shown a robust antidepressant effect which has led to an increase in clinical practices implementing its use to manage treatment-resistant depression. Traditionally, this therapy has been provided in both outpatient and inpatient settings, with anesthesia specialists and psychiatrists working collaboratively on most cases. Several studies have been conducted in various psychiatric settings to study the effects of ketamine in depression, mostly in a collaborative manner. Thorough search of the literature found no published reports on the use of ketamine infusions merely for clinical purposes in a psychiatric hospital setting, implemented solely by a psychiatric-based team without collaboration from anesthesia specialists. In an effort to explore the utilization of ketamine infusions, the Missouri University Psychiatric Center (MUPC), an acute mental inpatient facility, formed a ketamine infusion team composed solely of mental health clinicians and staff to investigate the use of ketamine infusions by a psychiatric team. To our knowledge, this is the first-time ketamine infusions have been administered by a clinically based psychiatric team in a psychiatric hospital. The MUPC ketamine team has proved that ketamine infusions may provide a unique intervention safely and efficaciously without the need for collaboration with other medical specialties since initiating this pilot program.

Introduction

Ketamine is an intravenous anesthetic that has acquired acceptance as an off-label treatment for acute suicidality and treatment-resistant depression in both inpatient and outpatient settings. Ketamine, as compared to conventional antidepressants, is a quick acting agent for mood improvement in critically ill patients. With this in mind, in an effort to expand treatment options available to inpatient psychiatric teams, MUPC developed a pilot study psychiatric ketamine infusion team to evaluate utilization of ketamine infusions in the acute psychiatric hospital setting. Since implementation in 2018, the team has safely and efficiently administered over 80 infusions to severely ill patients without the assistance of other medical disciplines, with excellent results.

Ketamine’s Utility in Psychiatry

Ketamine is a glutamate N-methyl-D-aspartate (NMDA) antagonist derived from phencyclidine (PCP) that has fewer negative effects and a lower potential for addiction.¹ It is a mild anesthetic with little effect on respiratory function.^2,3 Ketamine can induce an increase in blood pressure, heart rate, and cardiac output, as well as cause sensory changes, a decrease in mental sharpness, dissociation and memory problems.^1,3 Ketamine’s antagonistic effect on NMDA receptors has been shown to have antidepressant effects in animal models.⁴ In multiple investigations involving persons with both unipolar and bipolar depression, ketamine has shown to ameliorate depressive symptoms, notably suicidal ideation.^5,6

The ketamine infusion team at MUPC consists of an attending psychiatrist, a psychiatric physician assistant (PA), a board-certified psychiatric pharmacist, and a mental health registered nurse (Figure 1). A strategy for adequate physical and mental health screening, inclusion and exclusion criteria, dosing, and patient monitoring for the procedure was devised in collaboration with an inpatient psychiatrist, the hospital pharmacy, and patient safety officials. To ensure therapy appropriateness, an attending psychiatrist must evaluate the patient and assess the severity of depression with either the Patient Health Questionnaire (PHQ-9) or Quick Inventory of Depressive Symptomology (QIDS) and perform a cognitive assessment using the Mini-Mental Status Examination (MMSE) prior to treatment. A urine drug screen and pregnancy test (if necessary) are also performed.

Figure 1.

MUPC ketamine infusion team of all psychiatric staff (left to right): Muaid Ithman MD, Carolyn Kundert PA-C CAQ-Psychiatry, Michelle Jelinek RN, Robert Sobule PA-C CAQ-Psychiatry, Austin Campbell Pharm D BCPP.

The attending psychiatrist or PA prescribed each patient a series of two or three infusions, separated by at least 48 hours, with a target dose of 0.5 mg/ kg to be administered over 40 minutes. Infusions are given in a private room with blood pressure, heart rate, cardiac rhythm, respiratory rate, and oxygen saturation monitored at regular intervals throughout the treatment.

Efficacy of Treatment

Between 2018 and 2021, the team delivered more than 80 infusions (Figure 2). Treatment outcomes were favorable in terms of improved mood, decreased suicidal thoughts, patient tolerability, and minimal adverse effects (Table 1). The majority of individuals responded positively to the treatment, with considerable improvements in their depressive symptoms. The procedure has been well tolerated, with no patients requiring premature discontinuation of therapy. The most prevalent adverse effect was dissociation, which was addressed with a brief halt in infusion and, at times, intravenous lorazepam delivery. Other reported side effects included nausea and/or vomiting, excessive exhilaration, sedation, and an elevation in blood pressure. There were no major adverse effects that necessitated immediate life-saving measures. The data sample set revealed a 65.5 percent reduction from baseline of depressed symptoms. It should be emphasized that there were some differences in the depressed screening process, with some patients receiving the QIDS and others receiving the PHQ9. The two screenings are comparable but not interchangeable. The lack of follow-up screening after discharge complicates the analysis even more. To increase data accuracy, all patients are assessed simply with the PHQ-9 prior to infusion and again two weeks later (contacted via telephone by RN if discharged).

Figure 2.

Between 2018 and 2021, the MUPC all psychiatric team successfully and safely delivered more than 80 ketamine infusions. No other medical specialists were present.

Table 1.

MUPC IV Ketamine Infusion Data

Total Patients	32
Male	15
Female	17
Dosing	0.5mg/kg adjusted body weight infused over 40 minutes
Average Baseline Depression Screening (PHQ9 or QIDS)*	20.8
Average Baseline Follow Up Screening (PHQ9 or QIDS)*	7.5
Average Change in Screening Score (PHQ9 or QIDS)*	−14.1
% Change from Baseline in Screening Score (PHQ9 or QIDS)*	65.5%
Adverse Events Documented	Dissociation 5(15.6%); Nausea/Vomiting 3(9%); Extreme Euphoria 2(6%); Sedation 1(3%); BP Increase 1(3%)

^*Confounders affecting accuracy of data collected. When ketamine trials began, screening questionnaires varied between patients and not all patients participated on follow up screening. The QIDS and PHQ9 questionnaires are comparable but not interchangeable.

Conclusion

In view of the recent research on ketamine’s favorable impact on mental health and the early success of the MUPC ketamine infusion team, further research on ketamine’s utility in psychiatry is warranted. Results from this MUPC study, with particular respect to the robust effect and relative safety profile, indicate that intravenous ketamine can be used in an inpatient psychiatric setting under the supervision of a psychiatric team without the involvement of another specialty. This approach lays the groundwork for ongoing research into various intravenous drugs that psychiatric units can use to broaden and develop treatment modalities.