Delirium post-cardiac surgery: Incidence and associated factors

Abstract

Background: Post-operative delirium among cardiac surgery patients is a prevalent complication that associated with multiple negative outcomes.

Aim: This study aimed to assess delirium incidence, associated factors, and outcomes for adult patients who underwent elective cardiac surgery.

Design: An exploratory prospective cohort design was used for this study.

Methods: Delirium was diagnosed by the Confusion Assessment Method for the Intensive Care Unit. Incidence, preoperative, intraoperative, and post-operative variables for 245 patients during 3-month period were collected and analysed.

Results: Delirium developed in 9% (n = 22) of the sample. Patients with delirium were significantly older (mean age = 65.7, SD = 8.1), t (243) = -3.66, P < .05); had longer surgery time (mean time = 286.3, SD = 82.2), t (243) = -2.25, P < .05); received more blood post-surgery (t (243) = -3.86, P < .05); spent more time on mechanical ventilation (t [21.6] = -2.2, P < .05); had longer critical care unit stay (t [21.7] = -4.0, P < 0.05); and had longer hospitalization than patients without delirium.

Conclusions: The risk factors associated with development of delirium were advanced age and increased duration of surgery. Negative outcomes associated with delirium were increased duration of mechanical ventilation, increased volume of post-operative infused colloids and blood/products, increased critical care unit stay, and increased hospitalization. A multifactorial model for delirium risk factors should be considered to detect and work on potentially preventable delirium factors.

Relevance to clinical practice: Post-cardiac surgery delirium leads to longer mechanical ventilation time, increased ICU stay, and prolonged hospitalization. Delirium post-cardiac surgery is potentially preventable with appropriate identification of risk factors by nurses.

Keywords: associated factors; cardiac surgery; delirium; incidence; post-operative delirium.