الفهرس 
PATHOPHYSIOLOGY OF AGITATIONOnly 14 pages are availabe for public view
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Abstract
The term ‘agitation’ describes a syndrome of excessive motor activity, usually non-purposeful and associated with internal tension. Agitation is a frequent, challenging problem in intensive care units (ICUs) and affects at least 71% of patients, both young and old. Contributing factors include underlying illness, pain, anxiety, and delirium. Dangerous consequences range from poorly tolerated invasive therapy to self-destructive behavior (Siegel, 2003).
The highly stressful environment of the ICU may lead to a loss of orientation to time and place. Monotonous sensory input such as repetitive and noisy monitoring equipment, prolonged immobilization, especially with indwelling life support hardware, frequently interrupted sleep patterns and social isolation eventually contribute to the onset of brain dysfunction. However, this high-tech habitat is capable of reversing multiple organ-system insufficiency if the patient is able to tolerate the inherent stress of the environment. Therefore, normally beneficial responses to stress act to the patient’s harm in the artificial ICU environment and it is necessary to block them as selectively as possible (Crippen, 2003).
The list of causes and risk factors for agitation is really quite long. In practical terms, the causes and the risk factors of agitation in a critically ill patient in the ICU can fall into one of two categories: life threatening etiologies that necessitates immediate targeted interventions that could be life saving, and some problems that could cause significant discomfort but may need simple solutions (Honeiden and Seigel, 2010).
And so, when considering the differential diagnosis of agitation in critically ill patient, the intensivist should first seek immediately life-threatening causes e.g. hypoxia, hypoglycemia, hypotension, acute myocardial infarction, and sepsis. Common causes of delirium include infections, insufficiency of any major organ, medication or substance use or withdrawal, electrolyte or metabolic derangements and dehydration (Nassisi et al., 2006).
Patients in the ICU typically demonstrate complex disease states with a rapidly changing hemodynamic status, making their requirements for treatment of agitation fluctuate over time. These constantly changing requirements necessitate the need for bedside clinicians to reassess and redefine the goals of therapy frequently (Cohen et al., 2002).
The methods that are suitable for assessing the depth of sedation can be considered under two categories, objective or subjective assessment, depending on whether the techniques require the application of an index that’s derived from a quantifiable physiological variable (measurement system) or of a scoring system, respectively (Hole, 1993).
Non-pharmacological treatment must be considered first, common sense and good clinical practice being the rule, e.g. to avoid light anxiety in ICU patients. When simple measures are not sufficient to treat agitation, a pharmacological approach must be undertaken (Chevrolet and Jolliet, 2007).
An abundant literature is available on the treatment of agitation and behavioral disturbances, but only a small amount of information is specifically related to the ICU setting. Only a few classes of drugs have been sufficiently evaluated in the ICU to be mentioned here, that is, benzodiazepines, propofol, as well as classic and atypical neuroleptics (Chevrolet and Jolliet, 2007).
In 2010, Honeiden and Seigel suggested as a protocol for treatment of an agitated patient in the intensive care unit. They suggested first to review possible causes of agitation and try to correct reversible. If the patient is still agitated after excluding these reversible causes -that could be life threatening themselves- an approach to differentiate if the patient is suffering from pain, anxiety or delirium. And then treatment can be according to the situation using opioids, benzodiazepines or antipsychotics respectively (Honeiden and Seigel, 2010).