- Open Access
Gender differences in the use of atypical antipsychotic medications for ICU delirium
Critical Care volume 22, Article number: 220 (2018)
Intensive care unit (ICU) delirium, an acute fluctuating disturbance of cognition associated with critical illness, is associated with increased mortality, ICU length of stay, mechanical ventilation, and hospital costs [1,2,3]. Despite a link to increased long-term mortality, atypical antipsychotic medications (AAP) are frequently administered for the treatment of ICU delirium. Males have a higher risk of being diagnosed with ICU delirium (63% vs 36%) and being initiated on AAP (44% vs 40%) compared to females [4, 5].
In this retrospective investigation, we hypothesized that male gender was more likely to be associated with hyperactive symptoms of ICU delirium, and that males were more likely to be discharged on AAP after an ICU stay. After obtaining approval from the Institutional Review Board, we performed a retrospective analysis on patients admitted to the adult ICUs at the Penn State Health Milton S. Hershey Medical Center between January 2012 and December 2014. Charts were reviewed for the following inclusion criteria: age older than 18 years and AAP initiation in the ICU. Patients were excluded if they were on AAP prior to ICU admission. Documentation was analyzed for symptoms associated with AAP initiation based on the previously described Intensive Care Delirium Checklist Worksheet (ICDSC), pre-existing psychiatric diagnoses, and ICU type. Analyses were performed using SAS (v. 9.4; SAS, NC, USA) and significance was set at p < 0.05.
Of 12,984 patients admitted between 2012 and 2014, 346 (2.6%) patients were newly initiated on an AAP during their ICU stay, and 32 (8.6%) patients expired prior to discharge. In total, 346 patients and 314 patients were analyzed for initial and discharge-related variables, respectively (Table 1). No gender differences were observed in the concurrent psychiatric diagnoses of major depression (p = 0.13), bipolar disorder (p = 0.54), or schizophrenia (p = 0.99). However, males had a higher length of ICU stay compared to females (p = 0.002) but not total hospital stay (p = 0.07). As previously observed, males had higher rates of initiation of AAP (p = 0.0001) and continuation after discharge (p = 0.034). We demonstrated that males were more likely to have documentation of agitation (p = 0.032), hallucinations (p = 0.018), impulsiveness (p = 0.033), and combativeness (p = 0.001) compared to females. No differences were found in documentation of restlessness (p = 0.251), confusion (p = 0.60), insomnia (p = 0.70), lethargy (p = 0.34), or depressed affect (p = 0.62).
Prior studies have demonstrated higher rates of AAP initiation and continuation in male ICU patients. To our knowledge, our investigation is the first to show an association between male gender symptoms of hyperactive delirium and initiation of AAP in the ICU. As hyperactive symptoms are more visible and more likely to invoke safety concerns, we suspect that this leads to a higher rate of initiation and continuation of AAP in male patients. Thus, hyperactive symptoms drive the gender differences observed in AAP administration in the ICU. Further research is required to substantiate these findings and assess their clinical implications.
Atypical antipsychotic medications
Intensive care unit
Ely EW, Gautam S, Margolin R, et al. The impact of delirium in the intensive care unit on hospital length of stay. Intensive Care Med. 2001;27(12):1892–900.
Ely EW, Shintani A, Truman B, et al. Delirium as a predictor of mortality in mechanically ventilated patients in the intensive care unit. JAMA. 2004;291(14):1753–62.
Milbrandt EB, Deppen S, Harrison PL, et al. Costs associated with delirium in mechanically ventilated patients. Crit Care Med. 2004;32(4):955–62.
Marshall J, Herzig SJ, Howell MD, et al. Antipsychotic utilization in the intensive care unit and in transitions of care. J Crit Care. 2016;33:119–24.
Aldemir M, Ozen S, Kara IH, Sir A, Bac B. Predisposing factors for delirium in the surgical intensive care unit. Crit Care. 2001;5(1):265–70.
Availability of data and materials
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
Ethics approval and consent to participate
This study was approved by the Penn State College of Medicine IRB (STUDY00000628).
Consent for publication
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Karamchandani, K., Schoaps, R.S., Printz, J. et al. Gender differences in the use of atypical antipsychotic medications for ICU delirium. Crit Care 22, 220 (2018). https://doi.org/10.1186/s13054-018-2143-5