The Sedative and Haemodynamic effects Of Continuous Ketamine infusions on Intensive Care Unit patients (SHOCK-ICU): Investigating key outcomes, resource utilisation and staff decision-making: Clinical feasibility study protocol

Background: Between April 2022 and March 2023, 43.8% (88,259) patients admitted to Intensive Care Units (ICU) in the United Kingdom (UK) required breathing support through a ventilator, the majority require sedation. Unfortunately, mechanical ventilation is associated with high mortality and morbidity, and sedative agents currently used have significant side effects including hypotension and delirium. They are also implicated in long-term psychological sequelae such as major depression and posttraumatic stress disorder. Ketamine has been utilised in anaesthesia for over 50 years and has an excellent safety profile. The diverse properties of ketamine are the focus of much research currently, including its properties as a potent antidepressant. Ketamine has not been fully investigated in the context of ICU, and there are gaps in the evidence that warrant further investigation through a large randomised controlled trial. Preparatory work for such a study includes refining study designs, identifying key clinical and patient centred outcomes and exploring barriers to implementation, which is the focus of this work. Methods: SHOCK-ICU is a single centre, non-randomised, feasibility study assessing the feasibility of continuous ketamine infusions for the provision of sedation for 30 patients undergoing mechanical ventilation on the ICU. Data will be collected at baseline, daily until >48 h without mechanical ventilation, ICU discharge, and 90-days from enrolment. Data collection will include trial aspects such as expected recruitment, refusal, and follow-up rates, ability to collect data, and exploratory assessment of clinical efficacy markers. Primary outcome: The primary outcome is study feasibility; this will be assessed using pre-defined progression criteria that will aid design of future ketamine sedation studies.