Incidence and risk factors of delirium in patients after cardiac surgery: Modifiable and non-modifiable factors

Risk factors of postoperative delirium after cardiac surgery: a meta-analysis

Background

Postoperative delirium is a frequent event after cardiac surgery. This meta-analysis aimed to identify relevant risk factors.

Method

In this meta-analysis, all original researches regarding patients undergoing mixed types of cardiac surgery (excluding transcatheter procedures) and postoperative delirium were evaluated for inclusion. On July 28th 2020, we searched PubMed, Embase, Web of Science and Scopus. Data about name of first author, year of publication, inclusion and exclusion criteria, research design, setting, method of delirium assessment, incidence of delirium, odds ratio (OR) and corresponding 95% confidence interval (CI) of risk factors, and other information relevant was collected. OR and 95% CI were used as metrics for summarized results. Random effects model was applied.

Results

Fourteen reports were included with a total sample size of 13,286. The incidence of delirium ranged from 4.1 to 54.9%. Eight risk factors were identified including aging, diabetes, preoperative depression, mild cognitive impairment, carotid artery stenosis, NYHA functional class III or IV, time of mechanical ventilation and length of intensive care unit stay.

Conclusion

In this study several risk factors associated with postoperative delirium after cardiac surgery were identified. Utilizing the information may allow us to identifying patients at high risk of developing postoperative delirium prior to delirium onset.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01496-w.

Delirium is associated with high mortality in older adult patients with acute decompensated heart failure

BACKGROUND

Delirium is associated with high mortality after cardiac surgery. However, evidence on the epidemiology of delirium in patients with acute decompensated heart failure (ADHF) is limited. This study aimed to assess the incidence and prognostic impact of delirium in patients with ADHF.

METHODS

This single-center prospective observational study enrolled 132 consecutive patients with ADHF. We utilized the Diagnostic and Statistical Manual of Mental Disorders, fifth edition and classified the patients into two groups according to the presence or absence of delirium. The primary endpoint was 90-day all-cause mortality. The prognostic impact and risk factors of delirium were evaluated using multivariable Cox and logistic regression analyses, respectively.

RESULTS

The median patient age was 83 (interquartile range, 75-87) years. Approximately 51.5% were men. Delirium occurred in 36 (27.3%) patients, and hyperactive delirium was the most frequent type (86.1%). The 90-day all-cause mortality was higher in the patients with delirium than in those without (21.6% versus 3.9%, log-rank p = 0.002). Delirium was associated with higher mortality with an adjusted hazard ratio of 6.8 (95% confidence interval, 1.1-42.6, p = 0.042). The risk factors associated with delirium included advanced age, male sex, higher clinical frailty scale score, and dementia.

CONCLUSIONS

Delirium was associated with a higher 90-day all-cause mortality in the older adult patients with ADHF. Hyperactive delirium was the most common subtype.

The Effect of Massage With and Without Aromatic Oil on Delirium After Open-Heart Surgery: A Randomized Controlled Trial

Objective

The current study aimed to determine the effect of massage with and without aromatic oil on the delirium of patients hospitalized in the cardiac intensive care unit.

Methods

This study was a single-blind, randomized, controlled trial. Using a convenience method, 150 patients were selected and assigned into 3 groups: control, massage with aroma, and massage without aroma using the minimization method. Only routine care was provided for the control group. Brown massage with 4% rose oil in the base of sweet almond oil was given to the massage group with aroma 1 day after the surgery. The same steps and massage techniques with sweet almond oil were performed for the massage group without aroma. The incidence and severity of delirium were evaluated at the end of each day using the Neelon and Champagne Confusion Scale.

Results

Delirium scores were not significantly different among the 3 groups on the first, second, and third days (P > .05). Also, the incidence of delirium significantly decreased in all 3 groups from day 1 to day 3.

Conclusion

The results of this study could not prove the beneficial effects of massage with and without aroma on delirium incidence. Further studies are suggested to determine the best intervention to reduce delirium in patients undergoing coronary artery surgery.

Intraoperative xenon for prevention of delirium after on-pump cardiac surgery: a randomised, observer-blind, controlled clinical trial

BACKGROUND

Older patients undergoing cardiac surgery have a 40-60% risk of developing postoperative delirium (POD), which is associated with increased morbidity and mortality. In animals, xenon has been found to be neuroprotective. Little is known about its neuroprotective effects in humans. We evaluated whether xenon anaesthesia prevents POD in patients undergoing cardiac surgery.

METHODS

We conducted a randomised, observer-blind, controlled trial in which 190 patients 65 yr or older undergoing on-pump cardiac surgery were randomly allocated to xenon or sevoflurane anaesthesia. During cardiopulmonary bypass, propofol infusion was used for anaesthetic maintenance. Subjects were screened for POD daily during the first 5 postoperative days using the 3-Minute Diagnostic Interview for Confusion Assessment Method (CAM) or with a CAM version for patients in ICU (CAM-ICU). Other methods to detect delirium, such as chart review, were also used. Secondary outcomes included the duration and severity of POD, and postoperative cognitive function.

RESULTS

The overall incidence of POD was 41% (78/190). There was no statistically significant difference in the POD incidence between the xenon and sevoflurane groups (42.7% [41/96] vs 39.4% [37/94], P=0.583). The odds ratio for POD when comparing xenon with sevoflurane was 1.18 (95% confidence interval, 0.65-2.16).

CONCLUSIONS

In older patients undergoing cardiac surgery, xenon anaesthesia did not result in a significant reduction in POD. Based on these results alone, use of xenon cannot be recommended for this purpose.

CLINICAL TRIAL REGISTRATION

EudraCT: 2014-005370-11 (May 13, 2015; https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-005370-11).

Delirium post-cardiac surgery: Incidence and associated factors

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.

Clinical outcomes of automated anastomotic devices: A metanalysis

Background and Aims

We investigated neurological events, graft patency, major adverse cardiovascular events (MACEs), and mortality at 1 year following coronary artery bypass grafting (CABG) surgery using automated proximal anastomotic devices (APADs) and compared the overall rates with the current literature.

Methods

A systematic review of all available reports of APADs use in the literature was conducted. Cumulative incidence and 95% confidence interval (CI) were the main statistical indexes. Nine observational studies encompassing a total of 718 patients were included at the end of the selection process.

Results

The cumulative event rate of neurological complications was 4.8% (lower‐upper limits: 2.8‐8.0, P < .001; I² = 72.907%, P = .002; Egger's test: intercept = –2.47, P = 0.16; Begg and Mazumdar test: τ = −0.20, p = 0.57). Graft patency was 90.5% (80.4 to 95.7, P < .001; I² = 76.823%, P = .005; Egger's test: intercept = –3.04, P = .10; Begg and Mazumdar test: τ = −0.67, P = .17). Furthermore, the overall incidence of MACEs was 3.7% (1.3‐10.4, P < .001; I² = 51.556%, P = .103; Egger's test: intercept = –1.98, P =  < .11; Begg and Mazumdar test: τ = −0.67, P = .17). Finally, mortality within 1 year was 5% (3.5‐7, P < .001; I² = 29.675%, P = .202; Egger's test: intercept = –0.91, P = .62; Begg and Mazumdar test: τ = −0.04, P = .88).

Conclusions

APADs do not seem to be correlated with a reduction of either neurological events or mortality. By contrast, these tools showed satisfactory one‐year graft patency and a low incidence of MACEs. Further research on this topic is warranted.

Effect of organisational factors on the variation in incidence of delirium in intensive care unit patients: A systematic review and meta-regression analysis

BACKGROUND

Delirium occurs frequently in intensive care unit (ICU) patients and is associated with numerous deleterious outcomes. There is a large variation in reported delirium occurrence rates, ranging from 4% to 89%. Apart from patient and treatment-related factors, organisational factors could influence delirium incidence, but this is currently unknown.

OBJECTIVE

To systematically review delirium incidence and determine whether or not organisational factors may contribute to the observed delirium incidence in adult ICU patients.

METHODS

Systematic review of prospective cohort studies reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Included articles were independently assessed by two researchers. Quality of the articles was determined using the Strengthening the Reporting of Observational Studies in Epidemiology checklist. Subsequently, apart from patient characteristics, a meta-regression analysis was performed on available organisational factors, including hospital type, screening method and screening frequency.

DATA SOURCES

PubMed, Embase, CINAHL, and Cochrane Library databases were searched from inception to 27 January 2017, without language limitation.

RESULTS

A total of 9357 articles were found, of which 19 articles met the inclusion criteria and were considered as true delirium incidence studies. The articles were of good methodological quality (median [interquartile range] 32/38 [30-35] points), published between 2005 and 2016, originated from 17 countries. A total of 9867 ICU patients were included. The incidence rate of delirium varied between 4% and 55%, with a mean ± standard deviation of 29 ± 14%. Data relating to three organisational factors were included in the studies, but they were not significantly associated with the reported delirium incidence: hospital type (p 0.48), assessment methods (p 0.41), and screening frequency (p 0.28).

CONCLUSIONS

The mean incidence of delirium in the ICU was 29%. The organisational factors found including methods of delirium assessment, screening frequency, and hospital type were not related to the reported ICU delirium incidence.