Sedation and delirium in the intensive care unit

Sedation is an important aspect of intensive care practice. Utilized effectively it can reduce suffering on the intensive care unit. Strategies for providing sedation and the various pharmacological options are discussed in this article. Delirium is common in the intensive care unit and is important to recognize because of the association with increases in both morbidity and mortality. Various strategies exist for identifying and managing delirium. This article examines how delirium can be identified and both pharmacological and non-pharmacological treatment strategies.     

Sedation and delirium in the intensive care unit

Sedation is a widely used technique in critical care, and delirium is a common and serious complication of hospital stay. An understanding of drug choice and administration for safe use of sedation is important. Equally, an understanding of the mechanisms of delirium, along with preventative factors and treatments is an essential part of caring for many patients admitted to hospital. This article will cover these aspects of the subject.     

Sedation in the intensive care unit

Analgesics and sedatives are commonly prescribed in the ICU environment for patient comfort, however, recent studies have shown that these medications can themselves lead to adverse patient outcomes. Interventions that facilitate a total dose reduction in analgesic and sedative medications e.g. the use of nurse controlled protocol guided sedation, the combination of spontaneous awakening and breathing trials, and the use of short acting medications, are associated with improved outcomes such as decreased time of mechanical ventilation and ICU length of stay. This purpose of this review is to provide an overview of the pharmacology of commonly prescribed analgesics and sedatives, and to discuss the evidence regarding best prescribing practices of these medications, to facilitate early liberation from mechanical ventilation and to promote animation in critically ill patients.     

Sedation in the neurologic intensive care unit

Opinion statement Providing adequate sedation in the neurologic intensive care unit (ICU) depends on determination of proper goals for sedation, adequate assessment of the level of sedation, and appropriate choice of drug based on the patient’s physiology. The management of sedation in the ICU will influence long-term outcome. Delirium, anxiety, and pain must be identified and treated separately. The use of protocols can improve compliance with published evidence-based recommendations. Propofol and dexmedetomidine may be used for rapidly titratable sedation, benzodiazepines for anxiolysis, neuroleptics for treatment of delirium, and opiates for analgesia. Unique aspects of patients with acute brain disease, such as elevated intracranial pressure or status epilepticus, require adaptation of sedative regimens. Processed EEG monitoring and volatile anesthetic agents have not yet proven beneficial or practical for use in the ICU.     

Sleep and delirium in the intensive care unit

Intensive Care Unit (ICU) patients almost uniformly suffer from sleep disruption. Even though the role of sleep disturbances is not still adequately understood, they may be related to metabolic, immune, neurological and respiratory dysfunction and could worsen the quality of life after discharge. A harsh ICU environment, underlying disease, mechanical ventilation, pain and drugs are the main reasons that underlie sleep disruption in the critically ill. Polysomnography is the gold standard in evaluating sleep, but it is not feasible in clinical practice; therefore, other objective (bispectral index score [BIS] and actigraphy) and subjective (nurse and patient assessment) methods have been proposed, but their adequacy in ICU patients is not clear. Frequent evaluation of neurological status with validated tools is necessary to avoid excessive or prolonged sedation in order to better titrate patient-focused therapy. Hypnotic agents like benzodiazepines can increase total sleep time, but they alter the physiological progression of sleep phases, and decrease the time spent in the most restorative phases compared to the phases normally mediated by melatonin; melatonin production is decreased in critically ill patients, and as such, exogenous melatonin supplementation may improve sleep quality. Sleep disruption and the development of delirium are frequently related, both because of sleep scarcity and inappropriate dosing with sedatives. Delirium is strongly related to increased ICU morbidity and mortality, thus the resolution of sleep disruption could significantly contribute to improved ICU outcomes. An early evaluation of delirium is strongly recommended because of the potential to resolve the underlying causes or to begin an appropriate therapy. Further studies are needed on the effects of strategies to promote sleep and on the evaluation of better sleep in clinical outcomes, particularly on the development of delirium.     

Sedation and analgesia in the paediatric intensive care unit

Sedation and analgesia are a constant challenging issue in paediatric intensive care units, for ethical reasons among others. Basically, goals and available treatments in that context do not differ from those in adults. For instance, while we propose midazolam as the first choice benzodiazepine, there is no evidence for encouraging the use of one morphinomimetic rather than others in children. On the other hand, numerous paediatric specificities do exist: understanding and expression of pain both different and difficult, presence and involvement of the parents, pain assessment methods, pharmacology, pathologies. It is therefore mandatory to know these specificities to ensure a proper use of evaluation tools and therapeutics. The paucity of strong evidence from the literature does not allow producing definitive consensus guidelines. However, some practices can be highlighted such as the use of written protocol on pain/sedation evaluation and therapeutics adapted to children, literature data and local habits, the training of medical/nursing staff and the constitution of local referring team. A particular attention should be paid to propofol: its use longer than several hours should be strongly discouraged in infants and children due to the risk of Propofol Infusion Syndrome. Further clinical studies should be conducted in an attempt to provide answers to routine, daily issues and questions, for example, how to tailor the level of sedation to the needs of the patient, how to stop it, which drug must be preferred or what place for non-pharmacological approaches.     

Antimicrobial utilisation in 37 Australian and New Zealand intensive care units

This multi-centre point prevalence study reports on antimicrobial dosing patterns, including dose, mode of administration and type of infection, in 37 Australian and New Zealand intensive care units. Of 422 patients admitted to an intensive care unit on 8 May 2007, 195 patients (46%) received antimicrobial treatment, 123 patients (29%) received no antimicrobials and 104 patients (25%) received prophylactic antimicrobials only. Dosing data were available for 331 antimicrobials used to treat 225 infections in 193 patients. Respiratory (40%), abdominal (13%) and blood stream (12%) infections were most common. For adult patients, ticarcillin/clavulanate (23% or 40/177), meropenem (20% or 35/177) and vancomycin (18% or 32/177) were the most frequently used antibiotics; vancomycin was most commonly used in children (31% or 5/16). The majority of antimicrobials were administered as bolus doses or infusions of less than two hours (98% or 317/323); only six patients received extended or continuous infusions. The mode of administration was unknown in eight cases (4.1%). The total defined daily dose for adult patients receiving antimicrobial therapy was 2051 defined daily doses per 1000 patient days. Our results confirm that the use of continuous infusions remains rare, despite increased interest in continuous infusions for time-dependent antibiotics.     

Pain,agitation and delirium in the intensive care unit

Pain, agitation and delirium are common during critical illness and are associated with many adverse consequences. A key aim of critical care is the facilitation of a calm, comfortable patient who can interact with their family and staff. Intensive care unit (ICU) patients frequently have pain from a variety of sources, many of which are not readily appreciated or actively managed. This article explores the challenges of assessing pain in the ICU and outlines methods that can be used to better identify and manage pain in this patient group. Agitation in ICU is often multifactorial, with many of its sources under-recognized. We will discuss the potential reasons that ICU patients become agitated, methods for measuring agitation and the actions that can be taken to alleviate it. Although the use of sedative and anxiolytic drugs is common in ICU, their use is not without risks. This article will outline these risks, the variety of drugs available and how to use these drugs to a targeted effect. We will also explore delirium, its risk factors, precipitants and associated morbidity and mortality. This article will discuss how to diagnose delirium and the methods used to prevent and manage it.     

Pain,agitation and delirium in the intensive care unit

Pain, agitation and delirium are common during critical illness and are associated with many adverse consequences. A key aim of critical care is the facilitation of a calm, comfortable patient who can interact with their family and staff. Intensive care unit (ICU) patients frequently have pain from a variety of sources, many of which are not readily appreciated or actively managed. This article explores the challenges of assessing pain in the ICU and outlines methods that can be used to better identify and manage pain in this patient group. Agitation in ICU is often multifactorial, with many of its sources under-recognized. We will discuss the potential reasons that ICU patients become agitated, methods for measuring agitation and the actions that can be taken to alleviate it. Although the use of sedative and anxiolytic drugs is common in the ICU, their use is not without risks. This article will outline these risks, the variety of drugs available and how to use these drugs to a targeted effect. We will also explore delirium, its risk factors, precipitants and associated morbidity and mortality. This article will discuss how to diagnose delirium and the methods used to prevent and manage it.     

ICU-acquired neuromyopathy, delirium and sedation in intensive care unit

ICU-acquired neuromyopathy (NMAR) and delirium are the two most frequent and severe neurological complications of intensive care medicine. Their mechanisms still remain to be elucidated. The objective of this review is to address the potential role of sedation in occurrence of these complications. There is no evidence that sedation is involved in NMARs. However, the hypothesis that muscle inactivity induced by sedation fosters NMAR is an argument to discontinue or reduce sedatives infusion whenever possible. It is also recommended not to administer propofol more than 48 h at an infusion rate above 5 mg/kg per hour in patients with systemic inflammatory response syndrome, because of the risk of propofol infusion syndrome, which includes notably rhabdomyolysis. The relationship between delirium and sedation are controversial because in most studies, patients were considered delirious though being still sedated and multivariate analysis was lacking. One study showed that lorazepam given continuously was an independent risk factor for daily transition to delirium 24 h later with a 20% increase risk of every unit dose (expressed as log(e)mg). The impact of deepness, daily interruption or titration of sedation on the prevalence of delirium has never been assessed but it seems that deep sedation has to be avoided.     

Importance of recognizing and managing delirium in intensive care unit

Delirium is an acute and fluctuating change in mental status, with inattention and altered levels of consciousness. It is a common comorbidity in intensive care units (ICU), resulting in delayed withdrawal of mechanical ventilation, prolonged length of stay in ICU, increased ICU mortality and impaired long-term cognitive function of the survivors.     

Use of propofol infusion in Australian and New Zealand paediatric intensive care units

Despite the risk of propofol infusion syndrome, a rare but often fatal complication of propofol infusion in ventilated children and possibly adults, propofol infusion remains in use in paediatric intensive care units (PICU). This questionnaire study surveys the current pattern of use of this sedative infusion in Australian and New Zealand PICUs. Thirty-three of the 45 paediatric intensive care physicians surveyed (73%), from 12 of the 13 intensive care units, returned completed questionnaires. The majority of practitioners (82%) use propofol infusion in children in PICU, the main indication being for short-term sedation in children requiring procedures. 39% of respondents consider propofol infusion useful in ventilated children requiring longer-term sedation. 67% of paediatric intensivists use maximum infusion doses that may be considered dangerously high (> or = 10 mg/kg/h). Nineteen per cent use propofol infusion for prolonged periods (> 72 hours). A smaller proportion (15%) of respondents indicate that they may use both higher doses and prolonged periods of infusion, a practice likely to lead to a greater chance of serious adverse events. Knowledge of local protocols for the use of propofol infusion is associated with a significantly greater level of monitoring for possible adverse events. We suggest that national guidelines for the use of propofol infusion in children should be developed. These should include clear indications and contraindications to its use, a maximum dose rate and maximum period of infusion, with a ceiling placed on the cumulative dose given and clearly stated minimum monitoring requirements.