Susan Parkinson HEA3004

SEDATION PRACTICE IN CRITICAL CARE

The Department of Health (DoH), 2011 published statistics derived from a bi-annual census of adult critical care beds in The United Kingdom. The results show that on the census day 2,075 intensive care beds were occupied by level 3 patients, defined by The Comprehensive Critical Care document (DoH, 2000) as ‘patients who need advance/basic respiratory support and other organ support and complex care for multi organ failure’. Due to the complexity of patient’s illnesses at this level in a critical care setting (DoH, 2000) most patients who require sedation, defined as a ‘drug –induced depression of the level of consciousness.’ (The British Society of Gastroenterology, 2003), are often ventilated via an endotracheal tube, to promote effective ventilation and tube tolerance, (Rowe and Fletcher 2008), and to relieve anxiety, pain and to promote comfort and sleep’ (Punn and Dunn, 2007). It is widely acknowledged that the practice of sedation within this area can be complex and difficult and there are many different elements to be considered, (Woodrow, 2006).

During the care management of critically ill patient’s sedative and opioid medications are often a typical part of care, (Jacobi et al., 2002) This is mainly to improve comfort and to assist mechanical ventilation, but also to minimise physical and psychological stress, (Woodrow, 2006), however Bray et al., 2004, argues that ‘sedative drugs can be seen as a chemical restraint and should only be justified when there is a specific indication of the administration of them’. Delvin and Nasaway (2003), state that ‘delivering patients with the ideal level of sedation is a difficult intervention – under sedated patients remain anxious, may not ventilate properly and can develop posttraumatic stress disorder’, whist Ouimet et al (2007) highlighted a higher incidence of delirium and death in patients who were over sedated, furthermore an editorial by Petty (1998) suggested “ that over sedation is an conspiracy between the requirements of high dependency care and the available sedative agents and that an anxious patient requires more nursing intervention than an over sedated patient”. The American College of Critical Care Medicine, 2002 (ACCM), pain and sedation guidelines emphasised the significance of monitoring sedation therapy and titrating it to maintain patients in a slightly sleepy state, research highlights that this is not happening, (Chanques,et al, 2006). A prospective observational study by Salgado et al; (2010) concluded that the benefits of a minimal sedation regime reduced the length of hospital stay and costs, reduced mechanical ventilation times and improved patient outcomes. Punn and Dunn (2007) state ‘that the ideal sedative is one that works rapidly, provides anxiolysis, sedation and amnesia’ and Delvin (2008) endorses this by further suggesting ‘that the sedative that is effective is one that provides a rapid recovery, a predictable dose response, a lack of accumulation and non-toxic.’ However a systematic review by Ostermann et al; (2000) raised concerns that no current medications met the criteria and more recently, Regan & Boyd (2008) suggest that although sedation practice has evolved over the years, the ideal sedative agent has yet to be found,

The ACMM (2002) published guidelines on sedation and analgesic practice endorsed the use of Fentanyl or Morphine for pain relief and Midazolam or Propofol (appendix one), for short-term sedation and the use of Lorazepam (appendix one) for longer term sedation. Alternatively, a national survey on sedation practice in the United Kingdom by Reschreiter, et al; (2008) shows that sedation practice in the UK is significantly different using Alfentananil (appendix one) and Propofol for short term sedation and Morphine and Propofol for patients requiring sedation greater than 24 hours, and Lorazepam is seldom used. Research shows that during the past years there has been international debate over the choice of sedation agents in mechanically ventilated patients. A study by Walder, et al, (2002) concluded that both Propofol and Midazolam were effective agents but the duration of adequate sedation was longer with Propofol, conversely a German pharmacoeconomic trial by Muellejans et al; (2006) established that Remifentanil ( appendix one). and Propofol reduced ventilator days, shortened the length of hospital stay in comparison to the traditional treatment of midazolam and fentanyl. A more recent study assessed the viability of using minimal sedation (Salgado et al; 2010), the results shown that only 10% of 335 patients received sedation for more than 24 hours and furthermore 80% of the time on mechanical ventilation was without continuous sedation, also concluding that a minimal sedation regime is viable in reducing ventilation time, associated complications, a shorter stay in critical care, bed availability and related costs. A German survey by Martin et al; (2007) noted a trend away from a hypnosis-based approach with the traditional benzodiazepines ( appendix one) towards a more analgesia-based approach, however it was also in agreement with Ostermann et al; (2000) and Regan & Boyd (2008) that the ideal sedative has yet to be found. However, studies have shown that dexmedetomidine (appendix one) is a unique drug as it has a sedative; analgesic and anxiolysis affect and provides sedation without affecting the respiratory function, (Riker, et, al., 2009), however data on the safety of this drug are limited although a recent randomised controlled trial shown that compared to midazolam it reduced ventilation days, delirium and physiological factors, furthermore patients receiving it required less Propofol and morphine, (Martin, et al, 2003), the trial further concluded it would be an useful sedative medication, the factor of its significant cost limits its use in an critical care setting, (Martin, et, al.,2003) Studies have shown that there is a lack of nationally randomised controlled trials into sedative agents used in a critical care setting shown by the varying degree of agents used in different settings and countries.

Sedation holding – defined by Rowe and Fletcher, (2008) ‘as a daily interruption of sedative medications’ was researched as early as 2000 by Kress et al; they concluded that the daily holding of sedative agents led to reduced ventilation time, shortened lengths of stay, fewer complications and less neurological investigations, This was further endorsed by Rowe and Fletcher (2008) who found that sedation levels were lower in patient’s that had daily sedation holds allowing for assessment of neurological status and less accumulation of medications in the body; Furthermore evidence has shown that a reduction of complications such as ventilator-acquired-pneumonia, barotrauma (damage to the lungs) and bacteraemia were significantly lower in patients who received a daily sedation hold than those who did not (Schweickert et al ;2004). The National Institute of Clinical Guidelines (NICE, 2008), recommends a daily sedation hold to decrease the rates of infection in ventilated patients, Despite these recommendations and evidence-based-practice, research still shows that the incidence of VAP can vary from 9% - 68% in mechanically ventilated patients. Kress, (2002) further argue that daily interruption of sedatives alleviates these problems, but the impact of this practice on long-term psychological had not been studied well, their study concluded the practice of sedative interruption did not
Susan Parkinson HEA3004 result in adverse psychological outcomes, but reduced symptoms of post-traumatic stress disorder. A survey into sedation practice in the UK by Rechiercher, et, al., (2008) recorded that 78% of critical care settings stated that daily sedation holding is common practice, compared to Canada is 40%, Denmark 31% and Germany 34%, however the study also argues that only 53% of units in the UK audit the practice so in reality the percentage in the UK could possibly be lower. Delvin, et al (2002) concluded from an American survey in 2004 that many critical care settings were not using sedation holding due to a lack of staff training and acceptance of this practice, potential self-harm to the patient, respiratory problems and concern for the comfort of the patient. whereas Chan, et, al., (2001), demonstrated that using a multi-disciplinary approach to implement change, provided motivation and compliance in the development of their weaning protocol. Martin, et al., (2007), suggests it takes time for the impact of clinical research to be incorporated into practice as this was demonstrated in their reports between 2002 and 2006 that show 34% of ICU’s in Germany had developed the use of sedation holding into practice and sedation protocols had rapidly increased through these years, ( Martin,et, al.,2007).

The Ramsay Sedation Scoring tool was first introduced in 1974 ( Fullwood and Sargent, 2010), its main principle being to ensure the chosen agent of sedation gave the desired effect (Sessler, 2004), to adjust medication dosing, duration and to assess for over-sedation, its implementation at the time was controversial do to reported problems with a lack of validity and reliability, despites this and recommendations from the ACCM guidelines (2002) to use validated tools such as the Motor activity assessment tool, the Riker sedation tool and numerous others, surveys do show that this is still the most commonly used one, not only in the UK but also in Europe. In comparison, the

Susan Parkinson HEA3004
Richmond Agitation Sedation Scale was recommended for use by the ACCM (2002) and although its reliability and validity were excellent and its ability to detect changes in a patient over time its use has remained slow. However, regardless of the scale, patients should be able to maintain a level of wakeful, quiet comfort; have adequate control over pain and agitation; and be able to tolerate mechanical ventilation, (Kress, et, al., 2002). Although numerous sedation scales exist and are simple in concept, research shows that in the UK evidence based approach is still not universally followed, however it concluded that the practice of sedation scoring is higher in the UK than the other participating European countries, (Rechiercher, et, al., 2008).