Intravenous sedation for adults with profound acquired brain injury undergoing dental treatment – a seven-year service evaluation

Intravenous (IV) sedation with midazolam is a widely accepted, safe, and effective technique for delivering dental care [1]. There is research available on the use of IV sedation with midazolam in ASA 1 and 2 individuals and a moderate amount of studies for those with intellectual disabilities [1,2,3]. There is, however, limited evidence regarding IV sedation for medically complex patients, including those who are ASA grade 3 or have a profound acquired brain injury [4, 5].

An acquired brain injury (ABI) is an injury to the brain acquired after birth and can be divided into two main categories – traumatic and non-traumatic injuries. Traumatic brain injury is an external traumatic event in which damage to the brain is sustained. Common causes of traumatic brain injury include road traffic accidents, falls, sports-related injuries, violence resulting from concussions and skull fractures, or skull penetrating injuries. Non-traumatic brain injury occurs due to internal damage to the brain, often as a result of a stroke, cancer, infection or inflammation, leading to anoxia of the brain [6]. Recovery of patients after sustaining an ABI will depend on their age, pre-injury health and degree of damage to the brain tissues. Profound ABI can lead to severe lifelong impairments impacting daily activities, memory problems, communication difficulties, multimorbidity, seizures, depression, and behaviours that challenge [6]. Some patients will have a significant disorder of consciousness (DOC). Disorders of consciousness is a state of prolonged altered consciousness, categorised into coma, vegetative, or minimally conscious state based on neurobehavioral function [7]. These patients will appear awake or asleep but have minimal or no level of consciousness and are, therefore, often unable to cooperate with mouth opening during dental examination or treatment.

One or a combination of these impairments can lead to challenges in undertaking comprehensive dental assessments, capacity assessment and safe delivery of dental treatments. Mobility issues, either due to paralysis or involuntary movements, lead to reliance on wheelchairs and mobility aids, increasing barriers to accessing dental care in general dental practice [8]. People with profound ABI often have a chin-to-chest posture, making access to the oral cavity difficult. Oral hypersensitivity, where patients resist mouth opening when touched around the face, and powerful bite reflexes often make it impossible to examine inside the mouth [9, 10]. Cognitive impairments that fluctuate may increase barriers to undertaking pain histories, assessing capacity and obtaining consent [11]. Augmentative and alternative communication aids such as whiteboards, eye-gaze-based technologies, gestures, and symbols can support communication with those with limited verbal communication or severe aphasia [12].

The Royal Hospital of Neurodisability (RHN) is a specialised care facility in southwest London, home to 250 patients with profound ABI. Specialised wards are available for patients with behavioural changes, Huntington’s disease and those on ventilators. Around 75% of residents are fully or partially fed via an enteral route due to an inability to swallow safely. 30% have a tracheostomy tube in situ, which can be temporary or long-term when patients have poor airway reflexes and pharyngeal tone, leading to a higher risk of aspiration. 98% of people use wheelchairs, often customised to provide specific head support, and most can recline [13].

An onsite dental service is commissioned to provide National Health Service (NHS) dental care to all residents and is situated within the hospital’s grounds. The clinic is staffed by three part-time consultants in special care dentistry and a dental nurse manager. Rather than hoisting patients into a dental chair, a wheelchair recliner is used to treat patients in their wheelchairs.

For this patient cohort, dental management under local anaesthetic alone may not be possible due to limited mouth opening, behaviours that challenge the provision of care (henceforth referred to as ‘challenging behaviour’), anxiety, and uncontrolled movements [14]. Therefore, undertaking dental care under general anaesthetic (GA) or conscious sedation can be beneficial [15]. GA will allow completion of dental treatment in one treatment episode but comes with added risks of morbidity/mortality, requires transfer to an acute hospital, and often inpatient admissions for this patient group due to their medical complexities [16]. Transferring patients who require frequent medication and those with tracheostomies and enteral nutrition takes significant planning and requires specialised nurses to accompany them to external appointments. It is also more stressful for patients with an ABI to recover in a hospital setting with unfamiliar staff. Waiting lists for dental general anaesthesia have increased since the COVID-19 pandemic, with competing demands for theatre access from other surgical specialities, which could result in delays in care for this cohort.

Providing dental treatment under conscious sedation, in the form of IV sedation with midazolam onsite, offers many benefits. The dentist can administer the midazolam and undertake the dental treatment working with a sedation-trained dental nurse [17]. Appointment waiting times are shorter and can be planned around the patient’s schedule, which may include physiotherapy, occupational therapy, psychology, speech and language therapy, personal care, etc. Patients often have complex medical issues, so treatment can be planned to coincide with times when they are medically optimised and postponed if they become unwell.

Midazolam, a short-acting benzodiazepine, is most widely used for its anxiolytic, sedative, muscle relaxant, amnesic, and anticonvulsant properties [18]. During sedation with midazolam, cardio-respiratory patient monitoring is carried out using pulse oximetry and the patient is monitored clinically to assess their level of sedation. To determine the depth of sedation, the clinician subjectively assesses the patient’s speech (if verbal), responsiveness, cognition, change in facial expression, muscle tone and acceptance of treatment. The main disadvantage of midazolam is respiratory depression. People with an ABI often have compromised respiratory function [19], some with lower target oxygen saturation ranges, so midazolam must be titrated slowly, and the patients monitored carefully.

This evaluation aimed to review the IV sedation service within the dental department for patients with a profound brain injury at the RHN.

The objectives of this retrospective service evaluation include;

1. 1.

   To assess the effectiveness of sedation (Ellis sedation scoring and successful completion of exam/treatment) [18]

2. 2.

   To determine the level of sedation-related complications within this group