ABSTRACT
Introduction: Patients undergoing Deep brain stimulator (DBS) insertion require a high-resolution MRI for treatment planning prior to DBS surgery. This group of patients has movement disorders therefore traditionally the planning MRI is done under General anaesthesia to ensure patient immobility and to obtain good quality MRI images. Providing sedation/anaesthesia for MRI procedure during COVID-19 pandemic was challenging. When we restarted elective surgery during Covid-19 pandemic we were worried about aerosol generating procedures, therefore we looked at the feasibility of using Dexmedetomidine-Propofol sedation for treatment planning MRI as an alternative to General anaesthesia to prevent aerosol generating procedure. Method(s): We conducted retrospective review of anaesthetic records of all patients who underwent MRI under sedation for DBS planning from August 2020 to July 2021. We collected the data on patient demographics, Indication & target site for DBS, duration of sedation, complications during the scan, cardiovascular side effects like hypotension and bradycardia during scan, quality of image, duration of PACU stay and post scan complications. The quality of MRI imaging was assessed by the neurosurgeon who did the treatment planning. Sedation protocol: sedation was commenced with Propofol target controlled infusion (TCI) using Schneider model with effector site concentration (Cet) of 2 to 3 and Dexmedetomidine bolus dose of 1 microgram per kilogram was infused over 10 minutes. All the patients were induced to a Ramsay Sedation Scale of at least 5 or 6. Sedation was maintained with Dexmedetomidine infusion at 0.5 mcg/kg/hr and Propofol TCI (Schneider model Cet of 2 mcg/mL). Result(s): During our study period 15 patients underwent MRI under sedation with Propofol-Dexmedetomidine for DBS treatment planning. Of this 7 were males and 8 were females. Age range was from 39 to 75 years. The target site was Subthalamic nucleus in 9 patients, Thalamic nuclei in 4 patients and Globus pallidus internus in 2 patients. Duration of sedation ranged from 40 minutes to 100 minutes with a median of 45 minutes. 2 patients developed movement artefacts during scanning and were converted to GA, 3 patients developed hypotension (20% reduction from pre-induction blood pressure) requiring treatment with ephedrine. Five patients had sinus bradycardia (20% reduction from pre-induction heart rate) but did not require treatment. The qualities of images were classified as good in 11 patients and acceptable in 2 patients by the neurosurgeon involved in treatment planning. None of the patients needed repeat MRI scanning. Patient's stay in PACU ranged from 20-50 minutes with a mean of 26.5 minutes. Discussion(s): Dexmedetomidine-Propofol sedation has been widely used for sedation to perform MRI scans in paediatric patients, its use in adult patients is not well documented in the literature. Propofol enables smooth induction of sedation and rapid recovery however it may cause hypotension, decreased respiratory drive and upper airway obstruction. Dexmedetomidine has been used as a single sedative agent for MRI however its onset of action is slow and when used as a sole sedative agent large dose of dexmedetomidine is required and this may contribute to delayed recovery after sedation. Propofol-Dexmedetomidine combination has synergistic effects and is advantageous. Propofol can induce sedation smoothly, Dexmedetomidine can reduce dose required for sedation and suppression of motor response in healthy subjects (1). Combination of Dexmedetomidine- Propofol infusion reduced total Propofol dose and decreased the incidence of airway complications in a paediatric study (2). During our study period 2 patients sedation were converted to General anaesthesia, both patients had raised BMI and had laboured breathing under sedation causing transmitted head movement, therefore patient selection is important for successful scan under sedation. Propofol-Dexmedetomidine sedation can be used safely for treatment planning MRI in selective movement disorder patients.
ABSTRACT
Introduction: The COVID-19 pandemic led to mass redeployment of the clinical workforce to support intensive care units. Many junior doctors and nurses have little to no experience of dealing with patients with a tracheostomy. Tracheostomies are common in the critically unwell, with approximately 12,500 performed each year in England. Indications may include upper airway obstruction, airway protection, weaning, long-term ventilation, or secretion management;the clinical course of COVID-19 means more patients than ever are receiving a tracheostomy as part of their standard care. Complications are common, and the nature of harm may depend on the clinical environment and level of staff training. Despite difficult airway guidelines becoming widely accepted, tracheostomy emergencies were historically managed by relying on individually acquired skills. NAP41 highlighted a number of significant tracheostomy complications. As a consequence, national guidelines for emergency tracheostomy were published in 2012.2 The National Tracheostomy Safety Project advocates for improved care and safety for patients with a tracheostomy. Objectives: To establish the confidence and competence at dealing with tracheostomy emergencies in a cohort of existing and redeployed general intensive care staff. Methods: We devised and disseminated a survey to all clinical staff working on the general ICU in a single tertiary university hospital during the COVID-19 second wave.We received 40 responses from a diverse group including doctors of varying grades, ACCPs and nurses of ICU and non-ICU background. Results: The majority of respondents had looked after a patient with a tracheostomy within the last week. Most had experience with dealing with an emergency and were aware of the national tracheostomy safety project. Despite this, the majority were not confident at dealing with tracheostomy emergencies. Of concern, the majority had received no formal training on dealing with tracheostomy emergencies. The overwhelming majority would like further training. Conclusion: The clinical course of COVID-19 means many more patients than normal are receiving a tracheostomy as part of their standrad care. There is a clear need and want for further training for clinical staff on dealing with tracheostomy emergencies, especially in the event of a repeat mass redeployment.