Key Point #8: Expect "Confusion" Regarding the Role of Antipsychotic Medications
Some of the more surprising changes in the new PAD guidelines are the statements and recommendations regarding the role haloperidol plays in the prophylaxis and treatment of ICU delirium. In the 2002 guidelines, haloperidol was recommended as the preferred agent for the treatment of delirium in critically ill patients. This recommendation, as the authors acknowledge, was based on a series of case reports that suggested utility in the management of acutely agitated or delirious patients. The 2013 PAD guidelines provide no recommendation (for or against) haloperidol and concludes that there is "no published evidence that treatment with haloperidol reduces the duration in adult ICU patients." Although no studies have shown that haloperidol is effective in decreasing the duration of delirium, one pilot study reported a 20% reduction in delirium duration in patients who received the atypical antipsychotic quetiapine, when compared with placebo. This evidence resulted in a summary statement in the guideline that "atypical antipsychotics may reduce the duration of delirium in adult ICU patients." It may be that quetiapine or one of the other atypical antipsychotics would be helpful in treating delirium, but more studies are needed to confirm this. This is a big change from the 2002 guidelines, in that there are no recommendations to use any medication for the treatment of delirium.
If the clinical team decides to treat delirious patients with antipsychotics, it will be necessary to monitor patients for arrhythmias and QTc prolongation. The guideline suggests against using antipsychotic medications in patients who are at risk for torsades de pointes. Routine electrocardiography/telemetry monitoring for patients receiving these medications should be added to the institution's delirium management protocol. It may also be helpful to educate your colleagues on common QT-prolonging conditions and medications in which antipsychotics should be used, avoided, or given cautiously, to highlight just how ubiquitous these conditions are in the critical care setting.
The 2013 PAD guidelines now specifically address delirium prevention. According to the new guideline, the only recommended strategy for preventing ICU delirium is the use of early mobilization (see Key Point #10). Additionally, the PAD guidelines suggests against the prophylactic use of haloperidol or any atypical antipsychotics for the prevention of delirium.
Although an in-depth discussion regarding delirium management can be found in the article "Pharmacological Management of Sedation and Delirium in Mechanically Ventilated ICU Patients" in this issue, it is important to highlight a few things that pertain to guideline implementation. The lack of a clear pharmacological treatment strategy could leave many bedside clinicians asking how they are supposed to treat delirium. To prevent this, it is vital to provide education to the critical care team regarding the proper approach to delirium management. The cornerstone of delirium management is to identify and remove the etiology, if possible. Delirium can occur as a direct physiological consequence of a new medical condition (e.g., infection, pneumonia, sepsis). The patient with delirium may have a new medical problem that the ICU team has not yet identified. Delirium can also occur due to substance intoxication or withdrawal or as a side effect of medications. Benzodiazepines have been identified as an iatrogenic risk factor for the development of ICU delirium and thus serve as a potential modifiable treatment for patients found to be delirious. In fact, the guidelines suggest that "continuous intravenous infusions of dexmedetomidine rather than benzodiazepine infusions be administered for sedation in order to reduce the duration of delirium in these patients" except in patients receiving benzodiazepines for alcohol or benzodiazepine withdrawal. When educating staff on identifying etiology of delirium it may be helpful to use tools such as the THINK delirium mnemonic (as discussed in the article "Delirium Monitoring in the ICU: Strategies for Initiating and Sustaining Screening Efforts" in this issue), which lists potential causes such as toxic situations and new organ failures, hypoxemia, infection and sepsis, nonpharmacological interventions, and potassium (i.e., K+) and other electrolyte abnormalities.
There are no double-blind, randomized, placebo-controlled trials that teach us specifically what to do when a patient is delirious in our critical care setting. It may be most important to reorient staff that our reaction to delirium should be to stop benzodiazepine use (except in alcohol withdrawal), identify the etiology and correct it if possible, implement nonpharmacological delirium management strategies, use light sedation to maintain capacity for early mobility, and, lastly, medicate (with caution).