Person:

Marcantonio, Edward

Background— Delirium is a common outcome after cardiac surgery. Delirium prediction rules identify patients at risk for delirium who may benefit from targeted prevention strategies, early identification, and treatment of underlying causes. The purpose of the present prospective study was to develop a prediction rule for delirium in a cardiac surgery cohort and to validate it in an independent cohort.

Methods and Results— Prospectively, cardiac surgery patients ≥60 years of age were enrolled in a derivation sample (n=122) and then a validation sample (n=109). Beginning on the second postoperative day, patients underwent a standardized daily delirium assessment, and delirium was diagnosed according to the confusion assessment method. Delirium occurred in 63 (52%) of the derivation cohort patients. Multivariable analysis identified 4 variables independently associated with delirium: prior stroke or transient ischemic attack, Mini Mental State Examination score, abnormal serum albumin, and the Geriatric Depression Scale. Points were assigned to each variable: Mini Mental State Examination ≤23 received 2 points, and Mini Mental State Examination score of 24 to 27 received 1 point; Geriatric Depression Scale >4, prior stroke/transient ischemic attack, and abnormal albumin received 1 point each. In the derivation sample, the cumulative incidence of delirium for point levels of 0, 1, 2, and ≥3 was 19%, 47%, 63%, and 86%, respectively (C statistic, 0.74). The corresponding incidence of delirium in the validation sample was 18%, 43%, 60%, and 87%, respectively (C statistic, 0.75).

Conclusions— Delirium occurs frequently after cardiac surgery. Using 4 preoperative characteristics, clinicians can determine cardiac surgery patients’ risk for delirium. Patients at higher delirium risk could be candidates for close postoperative monitoring and interventions to prevent delirium.

OBJECTIVES: To determine whether patients who developed delirium after cardiac surgery were at risk of functional decline.

DESIGN: Prospective cohort study.

SETTING: Two academic hospitals and a Veterans Affairs Medical Center.

PARTICIPANTS: One hundred ninety patients aged 60 and older undergoing elective or urgent cardiac surgery.

MEASUREMENTS: Delirium was assessed daily and was diagnosed according to the Confusion Assessment Method. Before surgery and 1 and 12 months postoperatively, patients were assessed for function using the instrumental activities of daily living (IADL) scale. Functional decline was defined as a decrease in ability to perform one IADL at follow-up.

RESULTS: Delirium occurred in 43.1% (n=82) of the patients (mean age 73.7±6.7). Functional decline occurred in 36.3% (n=65/179) at 1 month and in 14.6% (n=26/178) at 12 months. Delirium was associated with greater risk of functional decline at 1 month (relative risk (RR)=1.9, 95% confidence interval (CI)=1.3–2.8) and tended toward greater risk at 12 months (RR=1.9, 95% CI=0.9–3.8). After adjustment for age, cognition, comorbidity, and baseline function, delirium remained significantly associated with functional decline at 1 month (adjusted RR=1.8, 95% CI=1.2–2.6) but not at 12 months (adjusted RR=1.5, 95% CI=0.6–3.3).

CONCLUSION: Delirium was independently associated with functional decline at 1 month and had a trend toward association at 12 months. These findings provide justification for intervention trials to evaluate whether delirium prevention or treatment strategies might improve postoperative functional recovery.

Background: Delirium is associated with many negative health outcomes. Postoperative sedation and opioid administration may contribute to delirium. We hypothesize that the use of dexmedetomidine and Intravenous acetaminophen (IVA) may lead to reduced opioid consumption and decreased incidence of postoperative delirium. This pilot study aims to assess feasibility of using dexmedetomidine and IVA in cardiac surgical patients, and estimate the effect size for incidence and duration of delirium. Methods: A total of 12 adult patients >60 years of age undergoing cardiac surgery were recruited and randomized into 4 groups: Propofol only (P), Propofol with IVA (P+A), Dexmedetomidine only (D), Dexmedetomidine with IVA (D+A). Preoperative baseline cognition and postoperative delirium was assessed daily until discharge. The feasibility was assessed by the number of patients who completed the study. Results: All patients completed the study successfully. The total incidence of delirium in the study population was 42% (5/12): 67% (2/3) in the group P, and 67% (2/3) in the group D, 33% (1/3) in D+A group and 0%(0/3) P+A group. The incidence of delirium was 17% (1/6) in the group receiving IVA compared to 67% (4/6) that did not receive IVA. The mean range of duration of delirium was 0-1 days. One patient expired after surgery, unrelated to the study protocol. One patient in the D group experienced hypotension (systolic blood pressure <90 mm of Hg.) Conclusions: The feasibility of performing a project is ascertained by the study. Patients receiving IVA had lower incidence of delirium compared to patients not receiving IVA which suggests that IVA may have a role in reducing the incidence of delirium. A prospective randomized, placebo-controlled trial will be the next step in investigating the role of dexmedetomidine and IVA in reducing the incidence of delirium.