one of the few well - understood features of intensive care unit ( icu ) delirium is its association with poor patient outcome .
risk factor stratification is essential to the understanding , prevention and treatment of any disorder , and is a cornerstone of scientific endeavor in clinical research .
the largest study on icu delirium risk factors to date is published in the previous issue of critical care .
delirium in the critical care setting is said to occur in 22% to over 80% of patients .
such broad variations in delirium incidence may be partly attributable to differences in predisposing risk factors , which may differ between icus .
co - morbidities present prior to icu admission have particularly seldom been considered in icu delirium studies ; several of them are discussed in the paper by van rompaey and colleagues .
physicians hold opinions on the risks and benefits of environmental factors ( for example , physical restraints ) affecting the patient once in the icu ; however , little is known about these factors .
human interaction , such as the effect visitors may have on delirium , remains unexplored in the critically ill patient .
these environmental features , discussed in van rompaey and colleagues ' paper , are important not only because they are inexpensive but also perhaps because they less likely to harm patients than poorly studied pharmacological interventions .
the patients described in the study were no longer intubated and thus were perhaps less ill ; in addition , not all centers collected all risk factor data . van rompaey and
colleagues nevertheless provide confirmation that several previously identified risk factors remain significant in this multicenter study , challenge other risk factors , and add several risk factors not previously described .
alcohol use is not screened for routinely , validated alcohol withdrawal scales remain under - used , and intervention for withdrawal is seldom incorporated into treatment plans .
this knowledge is all the more surprising because the relevant studies   identify alcohol abuse as a significant risk factor for developing delirium .
whether alternatives to routine care ( that is , benzodiazepines titrated to symptoms , rather than antipsychotics ) in these high - risk patients are of any benefit is unknown .
age has been considered a risk factor for delirium in non - icu populations and by some icu investigators .
when van rompaey and colleagues consider pre - existing cognitive dysfunction , tobacco use and alcohol , age does not appear to confer an additional risk for delirium .
if dementia is a risk factor but age is not  and studies considering pre - icu admission co - morbidities would indicate this is true    prevention or prophylaxis of this common and morbid disorder in the icu should consider different interventions than , say , similar initiatives on the wards .
several previously described predisposing factors ( psychoactive drugs , sedatives and opiates ) are revisited and their relative contribution to the risk of icu delirium is tempered by the case mix , and the addition of other variables .
the most novel elements in this study , however , are the environmental risks for icu delirium .
visible daylight , visitors and not being physically restrained seem to result in a lower incidence of delirium .
it is refreshing to know that in the high - tech environment of icus , someone still asks the question ' which inexpensive and nonmorbid approach is useful ? '
combinations of pharmacotherapy and nonpharmacologic interventions such as psychotherapy are used in a broad range of psychiatric disorders . in some situations ,
mental health is purportedly based on the ' functioning of a high - order nervous system in constant and complex relation with the personal and social environment ' .
several of the points raised by the authors ( such as the benefit of company ) offer simple venues for nonpharmacologic intervention .
the rise in odd ratios for delirium in physically restrained patients    yet make sense when one considers how fearful delirious patients are .
other reports have recently corroborated that nonpharmacologic interventions may impact on delirium ; early physiotherapy and ambulation appears to be associated with a decrease in delirium days in a recently conducted randomized , controlled study .
all recommended or clinically used antipsychotic drugs have been validated for the treatment of schizophrenia in young populations over short periods of time .
the potential for harm with these drugs is all the more worrisome given that their effectiveness and side effect profiles in older or critically ill populations are largely unknown .
there is an urgent need for carefully conducted studies differentiating cognitively intact patients from those with subsyndromal delirium   or frank delirium , which will integrate stratification based on risk factors such as those described by the authors .
only then can we move forward with the disorder , which arguably causes patients , their families and their caregivers the most distress during critical illness .
 icu delirium is associated with poor patient outcome . 
 risk factor stratification is essential to the understanding , prevention and treatment of this disorder . 
 alcohol consumption , smoking and prior cognitive impairment appear strongly correlated with delirium risk . 
 several potentially modifiable associations deserve prospective study : these include administration of sedatives and opiates ; multiple catheters ; as well as minimizing physical restraints and enabling visitors . 
None
Abbreviations
Competing interests