Preoperative physical activity in relation to postoperative delirium in elective cardiac surgery patients

Intraoperative Glycemic Variability and Mean Glucose are Predictors for Postoperative Delirium After Cardiac Surgery: A Retrospective Cohort Study

Purpose

Postoperative delirium (POD) is a common but serious complication after cardiac surgery and is associated with various short- and long-term outcomes. In this study, we investigated the effects of intraoperative glycemic variability (GV) and other glycemic variables on POD after cardiac surgery.

Patients and Methods

A retrospective single-center cohort analysis was conducted using data from electronic medical record from 2018 to 2020. A total of 705 patients undergoing coronary artery bypass graft surgery and/or valve surgery, and/or aortic replacement surgery were included in the analysis. Intraoperative GV was assessed with a coefficient of variation (CV), which was defined as the standard deviation of five intraoperative blood glucose measurements divided by the mean. POD assessment was performed three times a day in the ICU and twice a day in the ward until discharge by trained medical staff. POD was diagnosed if any of the Confusion Assessment Method for the Intensive Care Unit was positive in the ICU, and the Confusion Assessment Method was positive in the ward. Multivariable logistic regression was used to identify associations between intraoperative GV and POD.

Results

POD occurred in 306 (43.4%) patients. When intraoperative glycemic CV was compared as a continuous variable, the delirium group had higher intraoperative glycemic CV than the non-delirium group (22.59 [17.09, 29.68] vs 18.19 [13.00, 23.35], p < 0.001), and when intraoperative glycemic CV was classified as quartiles, the incidence of POD increased as intraoperative glycemic CV quartiles increased (first quartile 29.89%; second quartile 36.67%; third quartile 44.63%; and fourth quartile 62.64%, p < 0.001). In the multivariable logistic regression model, patients in the third quartile of intraoperative glycemic CV were 1.833 times (OR 1.833, 95% CI: 1.132–2.967, p = 0.014), and patients in the fourth quartile of intraoperative glycemic CV were 3.645 times (OR 3.645, 95% CI: 2.235–5.944, p < 0.001) more likely to develop POD than those in the first quartile of intraoperative glycemic CV.

Conclusion

Intraoperative blood glucose fluctuation, manifested by intraoperative GV, is associated with POD after cardiac surgery. Patients with a higher intraoperative GV have an increased risk of POD.

Prehabilitation to prevent complications after cardiac surgery - A retrospective study with propensity score analysis

Background

The rising prevalence of modifiable lifestyle-related risk factors (e.g. overweight and physical inactivity) suggests the need for effective and safe preoperative interventions to improve outcomes after cardiac surgery. This retrospective study explored potential short-term postoperative benefits and unintended consequences of a multidisciplinary prehabilitation program regarding in-hospital complications.

Methods

Data on patients who underwent elective cardiac surgery between January 2014 and April 2017 were analyzed retrospectively. Pearson’s chi-squared tests were used to compare patients who followed prehabilitation (three times per week, at a minimum of three weeks) during the waiting period with patients who received no prehabilitation. Sensitivity analyses were performed using propensity-score matching, in which the propensity score was based on the baseline variables that affected the outcomes.

Results

Of 1201 patients referred for elective cardiac surgery, 880 patients met the inclusion criteria, of whom 91 followed prehabilitation (53.8% ≥ 65 years, 78.0% male, median Euroscore II 1.3, IQR, 0.9–2.7) and 789 received no prehabilitation (60.7% ≥ 65 years, 69.6% male, median Euroscore II 1.6, IQR, 1.0–2.8). The incidence of atrial fibrillation (AF) was significantly lower in the prehabilitation group compared to the unmatched and matched standard care group (resp. 14.3% vs. 23.8%, P = 0.040 and 14.3% vs. 25.3%, P = 0.030). For the other complications, no between-group differences were found.

Conclusions

Prehabilitation might be beneficial to prevent postoperative AF. Patients participated safely in prehabilitation and were not at higher risk for postoperative complications. However, well-powered randomized controlled trials are needed to confirm and deepen these results.

The role of physical exercise and rehabilitation in delirium

PURPOSE

This article aims to analyze the intersections between delirium, physical exercise and rehabilitation, to better understand their interrelation and to visualize future lines of research.

METHODS

In this narrative review, after an overview of brain neurophysiology and function, as common substrates to understand the relationship between delirium and physical function, we explore the scientific evidence in: (1) physical dysfunction as a risk factor for delirium; (2) physical dysfunction as a symptom of delirium and (3) functional consequences related to delirium. Later, we analyze the physical therapy as one of the main strategies in multicomponent interventions to prevent delirium, by examining intervention studies including rehabilitation, which have shown to be effective in managing delirium. Finally, we analyze how frailty, delirium and physical exercise interact with each other.

RESULTS

This review confirms the close relationship between delirium and physical dysfunction; therefore, it is not surprising that physical exercise is widely used in delirium preventive strategies. Although delirium is catalogued as a neurocognitive disorder, scientific evidence shows that it is also a motor disorder, which is to be expected, since a vast body of literature already supports an interaction between motor and cognitive function.

CONCLUSION

The motor component of delirium should be taken into account when designing interventions or strategies to address delirium. These interventions may have a special importance in frail older adults.

Effect of perioperative administration of dexmedetomidine on delirium after cardiac surgery in elderly patients: a double-blinded, multi-center, randomized study

Objective

Postoperative delirium (POD) is a serious complication in elderly patients undergoing cardiac surgery. This study was aimed at investigating the effect of perioperative administration of dexmedetomidine for general anesthesia maintenance on occurrence and duration of POD in elderly patients after cardiac surgery.

Methods

One hundred and sixty-four patients were enrolled after cardiac surgery between June 2009 and December 2016. Patients were assigned by a computer-generated randomization sequence in a 1:1 ratio to receive dexmedetomidine general anesthesia maintenance or propofol general anesthesia maintenance. POD was assessed every day with confusion assessment method for intensive care units (ICU) during the first 5 postoperative days.

Results

There was no significance in incidence of POD between the dexmedetomidine group and the propofol group (P=0.0758). In patients treated with dexmedetomidine, the median onset time of delirium was delayed (second day vs first day) and the duration of delirium reduced (2 days vs 3 days) when compared with propofol-treated patients. The dexmedetomidine-treated patients also displayed a lower VAS score and less opiate analgesic consumption. No difference was observed in respect to other postoperative outcomes.

Conclusion

For elderly patients, perioperative administration of dexmedetomidine reduced incidence, delayed onset and shortened duration of POD after cardiac surgery.

Early delirium after cardiac surgery: an analysis of incidence and risk factors in elderly (≥65 years) and very elderly (≥80 years) patients

Introduction

Postoperative delirium is a common complication of cardiac surgery associated with increased mortality, morbidity, and long-term cognitive dysfunction. The aim of this study was to identify incidence and risk factors of delirium in elderly (≥65 years) and very elderly (≥80 years) patients undergoing major cardiac surgery.

Materials and methods

We performed a retrospective cohort analysis of prospectively collected data from a register of the cardiac surgery department of a tertiary referral university hospital between 2014 and 2016. Analysis was performed in two groups, ≥65 years and ≥80 years.

Results

We analyzed 1,797 patients ≥65 years, including 230 (7.24%) patients ≥80 years. Delirium was diagnosed in 21.4% (384/1,797) of patients above 65 years, and in 33.5% (77/230) of octogenarians. Early mortality did not differ between patients with and without delirium. Intensive care unit (ICU) stay (p<0.001), hospital stay (p<0.001), and intubation time (p=0.002) were significantly longer in patients undergoing cardiac surgery ≥65 years with delirium. According to multivariable analysis, <65 years, age (odds ratio [OR] 1.036, p=0.002), low ejection fraction (OR 1.634, p=0.035), diabetes (1.346, p=0.019), and extracardiac arteriopathy (OR 1.564, p=0.007) were found to be independent predictors of post-cardiac surgery delirium. Postoperative risk factors for developing delirium ≥65 years were atrial fibrillation (1.563, p=0.001), postoperative pneumonia (OR 1.896, p=0.022), elevated postoperative creatinine (OR 1.384, p=0.004), and prolonged hospitalization (OR 1.019, p=0.009).

Conclusion

Patients above 65 years of age with postoperative delirium have poorer outcome and are more likely to have prolonged hospitalization and ICU stay, and longer intubation times, but 30-day mortality is not increased. In our study, eight independent risk factors for development of post-cardiac surgery delirium were age, low ejection fraction, diabetes, extracardiac arteriopathy, postoperative atrial fibrillation, pneumonia, elevated creatinine, and prolonged hospitalization time.

Preoperative exercise capacity is associated with the prevalence of postoperative delirium in elective cardiac surgery

BACKGROUND

Postoperative delirium (POD) is a critical complication that is closely associated with mortality and major morbidity in elective cardiac surgery. The identification of patients at risk for POD is crucial but has not been fully explored.

AIMS

The aim of this study was to determine the predictive value of the assessment of preoperative exercise capacity for POD.

METHODS

We enrolled 313 consecutive patients (mean age, 68.6 ± 14.8 years) undergoing elective cardiac surgery. We measured physical functions such as the 6-minute walking distance (6MWD) and Timed Up-and-Go test (TUG) before surgery. The assessment of delirium was conducted every 8 h from the day of surgery to 5 days after surgery using the Intensive Care Delirium Screening Checklist.

RESULTS

POD occurred in 46 patients (14.6%). Age, 6MWD, TUG, serum hemoglobin, estimated glomerular filtration rate, and length of intensive care unit stay were significantly different based on the presence or absence of POD (p < 0.05 for each). After multivariate analysis, 6MWD remained a statistically significant indicator for developing POD (OR 0.98; p = 0.02). The cut-off value of 6MWD for predicting POD was 345 m (AUC = 0.75; p = 0.001).

CONCLUSIONS

Poor exercise capacity was found to be an independent predictor of POD following elective cardiac surgery. This finding suggests the importance of preoperative functional evaluation in the prevention and management of POD in cardiac surgery patients.