Postoperative delirium: perioperative assessment, risk reduction, and management

Association of postoperative delirium with cognitive outcomes: A meta-analysis

STUDY OBJECTIVE

To determine the association between postoperative delirium (POD) and cognitive outcomes at least 1 month after surgery in elderly patients, and synthesize the dynamic risk trajectory of cognition impairment after POD.

DESIGN

Meta-analysis searching PubMed, Cochrane and EMBASE from inception to November 1, 2020. The terms postoperative delirium, delirium after surgery, postsurgical delirium, postoperative cogniti*, postoperative cognitive dysfunction, postoperative cognition decline, cognitive decline, cognitive impair* and dement* were searched alone or in combination.

MEASUREMENTS

Inclusion criteria were prospective cohort studies investigating the association between POD and cognitive outcomes in patients aged ≥60 years underwent surgery. The primary outcome was the association between POD and cognitive outcomes at 1 or more months after surgery. We considered cognitive outcomes measured up to 12 months after surgery as short-term and beyond 12 months as long-term. Two authors performed the study screening, data extraction and quality assessments. Effect sizes were calculated as Hedges g or Odds ratio (OR) based on random- and fixed-effects models. Meta-regression was conducted to analyze the role of potential contributors to heterogeneity.

MAIN RESULTS

Eighteen studies were included. Our result showed a significant and medium association between POD and cognitive outcomes after at least 1 month postoperatively (g = 0.61 95% CI 0.43-0.79; I² = 65.1%), indicating that patients with POD were associated with worse cognitive outcomes. The association of POD with short- and long-term cognitive impairment were also both significant (short-term: g = 0.46 95% CI 0.24-0.68; I² = 53.1%; and long-term: g = 0.82 95% CI 0.57-1.06; I² = 57.1%). A multivariate meta-regression suggested that age and measure of delirium were significant sources of heterogeneity. POD was also associated with the significant risk for dementia (OR = 6.08 95% CI 3.80-9.72; I² = 0) as well as attention (OR = 1.74 95% CI 1.13-2.68; I² = 0), executive (OR = 1.33 95% CI 1.00-1.80; I² = 0) and memory impairment (OR = 1.59 95% CI 1.20-2.10; I² = 43.0%). Additionally, our results showed that the risk trajectory for cognitive decline associated with POD within five years after surgery revealed exponential growth.

CONCLUSIONS

This is the first meta-analysis quantifying the association between POD and cognitive outcomes. Our results showed that POD was significantly associated with worse cognitive outcomes, including short- and long-term cognitive outcomes following surgery.

Effects of general versus subarachnoid anaesthesia on circadian melatonin rhythm and postoperative delirium in elderly patients undergoing hip fracture surgery: A prospective cohort clinical trial

BACKGROUND

Circadian rhythm disturbance is common postoperatively in older patients with hip fractures, which may contribute to the development of postoperative delirium (POD). As a reliable biomarker of endogenous circadian rhythms, melatonin regulates the sleep-wake cycle and environmental adaptation, and its secretory rhythm may be modified by anaesthesia and surgery. This study compared the impact of subarachnoid anaesthesia (SA) and general anaesthesia (GA), on the peak of melatonin secretion (primary outcome), the circadian rhythm of melatonin, cortisol and sleep, and the POD incidence (secondary outcome).

METHODS

In this prospective cohort observational study, hip fracture surgery patients were enrolled and assigned to receive either SA or GA. Postoperative plasma melatonin and cortisol levels were dynamically measured every six hours on seven time-points, and the circadian rhythm parameters including mesor, amplitude, and acrophase were calculated. Subjective and objective sleep assessments were performed by sleep diaries and sleep trackers, respectively. The Confusion Assessment Method was used twice daily by a specific geriatrician to screen for POD occurrence.

FINDINGS

In a cohort of 138 patients who underwent hip fracture surgery, the circadian rhythm disruption of the patients in the GA group (n=69) was greater than the SA group (n=69). Compared with SA, GA provided the lower peak concentration, mesor, and amplitude of melatonin secretion on postoperative day 1 (p < 0.05). Patients in the GA group experienced higher awakenings, more sleep deprivation, and poor sleep quality on surgery day (p < 0.05). A proportion of 12 patients in the SA group (17.4%) and 24 patients in the GA group (34.8%) experienced POD (p = 0.020).

INTERPRETATION

These results suggest that SA may be superior to GA in elderly patients undergoing hip fracture surgery as SA is associated with less impairment of the melatonin rhythm and sleep patterns, and fewer POD occurrences.

FUNDING

The study was supported by the National Natural Science Foundation of China (81971012, 81873726, 81901095, 81701052, and 81801070), Key Clinical Projects of Peking University Third Hospital (BYSYZD2019027), and Peking University "Clinical Medicine plus X" Youth Project (PKU2020LCXQ016).

Development and validation of a risk score for predicting postoperative delirium after major abdominal surgery by incorporating preoperative risk factors and surgical Apgar score

STUDY OBJECTIVE

To develop and validate a simple delirium-predicting scoring system in patients undergoing major abdominal surgery by incorporating preoperative risk factors and intraoperative surgical Apgar score (SAS).

DESIGN

Observational retrospective cohort study.

SETTING

A tertiary general hospital in China.

PATIENTS

1055 patients who received major abdominal surgery from January 2015 to December 2019.

MEASUREMENTS

We collected data on preoperative and intraoperative variables, and postoperative delirium. A risk scoring system for postoperative delirium in patients after major open abdominal surgery was developed and validated based on traditional logistic regression model. The elastic net algorithm was further developed and evaluated.

MAIN RESULTS

The incidence of postoperative delirium was 17.8% (188/1055) in these patients. They were randomly divided into the development (n = 713) and validation (n = 342) cohorts. Both the logistic regression model and the elastic net regression model identified that advanced age, arrythmia, hypoalbuminemia, coagulation dysfunction, mental illness or cognitive impairments and low surgical Apgar score are related with increased risk of postoperative delirium. The elastic net algorithm has an area under the receiver operating characteristic curve (AUROC) of 0.842 and 0.822 in the development and validation cohorts, respectively. A prognostic score was calculated using the following formula: Prognostic score = Age classification (0 to 3 points) + arrythmia + 2 * hypoalbuminemia + 2 * coagulation dysfunction + 4 * mental illness or cognitive impairments + (10-surgical Apgar score). The 22-point risk scoring system had good discrimination and calibration with an AUROC of 0.823 and 0.834, and a non-significant Hosmer-Lemeshow test P = 0.317 and P = 0.853 in the development and validation cohorts, respectively. The bootstrapping internal verification method (R = 1000) yielded a C-index of 0.822 (95% CI: 0.759-0.857).

CONCLUSION

The prognostic scoring system, which used both preoperative risk factors and surgical Apgar score, serves as a good first step toward a clinically useful predictive model for postoperative delirium in patients undergoing major open abdominal surgery.

A clinical risk analysis of early post-operative delirium after laparoscopic colorectal cancer surgery in elderly patients: a retrospective study

PURPOSE

Early post-operative delirium (EPOD) is a frequent complication following colorectal surgery. The present study investigated the risk factors for EPOD after laparoscopic colorectal surgery in elderly patients.

METHODS

A retrospective study was conducted among 208 patients ≥70 years old who underwent laparoscopic colorectal surgery. Univariate and multivariate analyses were performed to determine the clinicopathological factors associated with the EPOD.

RESULTS

The overall incidence of EPOD was 10.1% (21/208). The univariate analysis showed that an older age (≥80 years old; P=0.002), sleeping pill medication before surgery (P=0.037), a history of dementia (P=0.030) and cerebrovascular disease (P=0.017), elevated levels of D-dimer (P=0.016), maximum intraoperative temperature ≥37 °C (P=0.036), and non-continuous usage of droperidol with analgesia (P=0.005) were associated with EPOD. The multivariate logistic regression analysis revealed an older age (≥80 years old; odds ratio [OR]: 6.26, 95% confidence interval [CI]: 1.94-20.15, P=0.002), sleeping pill medication before surgery (OR: 5.39, 95% CI: 1.36-21.28, P=0.016), history of cerebrovascular disease (OR: 3.91, 95% CI: 1.12-13.66, P=0.033), and maximum intraoperative temperature ≥37 °C (OR: 5.10, 95% CI: 1.53-16.92, P=0.008) to be independent risk factors. When the patients were divided into groups according to the number of positive risk factors, the prevalence rate was 6.5%, 16.0%, and 63.6% for patients with 1, 2, and 3 positive risk factors, respectively.

CONCLUSION

Our findings suggest that an older age, sleeping pill medication before surgery, history of cerebrovascular disease, and maximum intraoperative temperature ≥37 °C are independent risk factors of EPOD after laparoscopic colorectal surgery in elderly patients.

The risk factors of postoperative delirium in general anesthesia patients with hip fracture: Attention needed

Delirium is a common postoperative complication of patients with hip fracture, yet the risk factors for postoperative delirium in patients with hip fracture remain unclear. We aimed to evaluate the associated risk factors of postoperative delirium in patients with hip fracture, to provide evidence for formulating coping measures of postoperative delirium prevention and treatment in clinical practice.Patients undergoing surgery for hip fracture from March 1, 2018 to September 30, 2020 in our hospital were included. The related characteristics and related lab examination results were reviewed and collected. The univariate and logistic regression analyses were performed to identify the potential risk factors.A total of 462 patients were included, the incidence of postoperative delirium in patients with hip fracture was 16.02%. Logistic regression analyses indicated that history of delirium (OR = 4.38, 1.15-9.53), diabetes mellitus (OR = 5.31, 1.23-10.75), hypoalbuminemia (OR = 4.97, 1.37-9.86), postoperative hypoxemia (OR = 5.67, 2.24-13.42), and body mass index (BMI) (kg/m2) (OR = 3.03, 1.36-6.18) were the independent risk factors for the delirium in patients with hip fracture surgery (all P < 0.05). The cutoff value of postoperative blood sugar, albumin, and BMI for delirium prediction was 8.05 (mmol/L), 32.26 (g/L), and 19.35 (kg/m2), respectively, and the area under curve of postoperative blood sugar, albumin, and BMI was 0.792, 0.714, and 0.703, respectively.Those patients with a history of delirium, postoperative hypoxemia, blood glucose ≥8.05 mmol/L, albumin ≤32.26 g/L, and BMI ≤19.35 kg/m2 particularly need the attention of healthcare providers for the prevention of delirium.

Perioperative Vascular Biomarker Profiling in Elective Surgery Patients Developing Postoperative Delirium: A Prospective Cohort Study

Background: Postoperative delirium (POD) ranks among the most common complications in surgical patients. Blood-based biomarkers might help identify the patient at risk. This study aimed to assess how serum biomarkers with specificity for vascular and endothelial function and for inflammation are altered, prior to or following surgery in patients who subsequently develop POD. Methods: This was a study on a subcohort of consecutively recruited elective non-cardiac as well as cardiac surgery patients (age > 60 years) of the single-center PROPDESC trial at a German tertiary care hospital. Serum was sampled prior to and following surgery, and the samples were subjected to bead-based multiplex analysis of 17 serum proteins (IL-3, IL-8, IL-10, Cripto, CCL2, RAGE, Resistin, ANGPT2, TIE2, Thrombomodulin, Syndecan-1, E-Selectin, VCAM-1, ICAM-1, CXCL5, NSE, and uPAR). Development of POD was assessed during the first five days after surgery, using the Confusion Assessment Method for ICU (CAM-ICU), the CAM, the 4-‘A’s test (4AT), and the Delirium Observation Scale (DOS). Patients were considered positive if POD was detected at least once during the visitation period by any of the applied methods. Non-parametric testing, as well as propensity score matching were used for statistical analysis. Results: A total of 118 patients were included in the final analysis; 69% underwent non-cardiac surgery, median overall patient age was 71 years, and 59% of patients were male. In the whole cohort, incidence of POD was 28%. The male gender was significantly associated with the development of POD (p = 0.0004), as well as a higher ASA status III (p = 0.04). Incidence of POD was furthermore significantly increased in cardiac surgery patients (p = 0.002). Surgery induced highly significant changes in serum levels of almost all biomarkers except uPAR. In preoperative serum samples, none of the analyzed parameters was significantly altered in subsequent POD patients. In postoperative samples, CCL2 was significantly increased by a factor of 1.75 in POD patients (p = 0.03), as compared to the no-POD cohort. Following propensity score matching, CCL2 remained the only biomarker that showed significant differences in postoperative values (p = 0.01). In cardiac surgery patients, postoperative CCL2 serum levels were more than 3.5 times higher than those following non-cardiac surgery (p < 0.0001). Moreover, after cardiac surgery, Syndecan-1 serum levels were significantly increased in POD patients, as compared to no-POD cardiac surgery patients (p = 0.04). Conclusions: In a mixed cohort of elective non-cardiac as well as cardiac surgery patients, preoperative serum biomarker profiling with specificity for vascular dysfunction and for systemic inflammation was not indicative of subsequent POD development. Surgery-induced systemic inflammation—as evidenced by the significant increase in CCL2 release—was associated with POD, particularly following cardiac surgery. In those patients, postoperative glycocalyx injury might furthermore contribute to POD development.

Platelet aggregometry for hip fracture surgery in patients treated with clopidogrel: a pilot study

Surgery for hip fractures should be performed within 48 h from patient's admission. However, several factors including chronic antiplatelet therapy could delay operation. Among the totality of patients taking clopidogrel, up to 30% are resistant to the drug and have a normal platelets reactivity. We propose thromboelastography (TEG) with an ADP Platelet Mapping assay kit to assess platelet aggregation, a safe tool that could help to avoid surgery delay in those patients treated with antiplatelet therapy. A patient's blood sample was collected for aggregometry. If MA-ADP and platelets aggregation (%) were within normal values, the patient was fit for immediate surgery with neuraxial anesthesia and ultrasound-guided nerve block. If one of the two parameters or both were deranged, a mortality risk assessment was estimated. In the low risk category, the patients waited till normalization of the parameters, whereas in the high-risk group a general anesthesia and peripheral antalgic block was carried out. Nine patients were enrolled. Four of them showed normal aggregometry and surgery was performed within 24 h from admission. Two patients were classified as high mortality risk and surgery was carried out under general anesthesia. Three patients awaited operation till normalization of parameters. No peri or post-operative complications were reported. An aggregometry-guided protocol can safely expedite hip fracture surgery in patients taking clopidogrel. Nonetheless, in presence of a normal platelets function, clinician can opt for a neuraxial instead of general anesthesia reducing the incidence of postoperative delirium and cognitive dysfunction.Trial registration: prospectively registered at clinicaltrials.gov (NCT04642209; date of registration: 23rd November 2020).

Are dexmedetomidine and olanzapine suitable to control delirium in critically ill elderly patients? A retrospective cohort study

BACKGROUND

The efficacy and safety of dexmedetomidine and olanzapine for delirium control in critically ill elderly patients without ventilation or surgery are not known.

METHODS

The efficacy and safety of dexmedetomidine and olanzapine for controlling delirium were evaluated in a retrospective cohort of critically illness by assessing the sedation level, drug dose/duration, combination rate with other sedatives, adverse effects, intubation rate and prognosis.

RESULT

The maximum (1.61 ± 1.56 vs. 2.70 ± 1.01, p < 0.001), average (-0.57 ± 0.88 vs. 0.88 ± 0.73, p < 0.001), and minimum (-1.67 ± 1.04 vs. -1.37 ± 1.01, p = 0.014) RASS scores of 263 patients were lower after treating with dexmedetomidine than treating with olanzapine. Drug use duration (4.83 ± 2.67 days vs. 5.87 ± 3.14 days, p = 0.005) and sedative combination rates (13.56% vs. 40.00%, p = 0.003) were lower when treating with dexmedetomidine than that with olanzapine. A comparison of adverse effects between dexmedetomidine and olanzapine revealed respiratory depression (16.95% vs. 2.84%, p < 0.001), hypoxia (13.56% vs. 2.76%, p < 0.001) and hypotension (11.02% vs. 3.45%, p = 0.007). Intubation rates (22.88% vs. 12.41%, p = 0.023) and the length of hospital stay (9.30 ± 4.90 days vs. 8.83 ± 3.34 days, p < 0.001) were higher in patients treated with dexmedetomidine than that with olanzapine. Mortality rates, cognitive prognosis, and delirium recurrence rates were similar between groups. Age, severe cardiopulmonary disease, APACHE II scores, dexmedetomidine dose, minimum RASS score and sedative combination were significantly (p < 0.05) associated with the adverse effects of dexmedetomidine. Respiratory depression, hypoxia and hypotension in the olanzapine group all occurred during combination with benzodiazepines.

CONCLUSIONS

Dexmedetomidine achieved more satisfactory sedative effects on delirium control, but olanzapine was safer.

Effects of comprehensive geriatric care models on postoperative outcomes in geriatric surgical patients: a systematic review and meta-analysis

Background

The elderly population is highly susceptible to develop post-operative complications after major surgeries. It is not clear whether the comprehensive geriatric care models are effective in reducing adverse events. The objective of this systematic review and meta-analysis is to determine whether the comprehensive geriatric care models improved clinical outcomes, particularly in decreasing the prevalence of delirium and length of hospital stay (LOS) in elderly surgical patients.

Method

We searched Medline, PubMed, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Emcare Nursing, Web of Science, Scopus, CINAHL, ClinicalTrials. Gov, and ICTRP between 2009 to January 23, 2020. We included studies on geriatric care models in elderly patients (≥60 years) undergoing elective, non-cardiac high-risk surgery. The outcomes were the prevalence of delirium, LOS, rates of 30-days readmission, and 30-days mortality. We used the Cochrane Review Manager Version 5.3. to estimate the pooled Odds Ratio (OR) and Mean Difference (MD) using random effect model analysis.

Results

Eleven studies were included with 2672 patients [Randomized Controlled Trials (RCTs): 4; Non-Randomized Controlled Trials (Non-RCTs): 7]. Data pooled from six studies showed that there was no significant difference in the prevalence of delirium between the intervention and control groups: 13.8% vs 15.9% (OR: 0.76; 95% CI: 0.30–1.96; p = 0.57). Similarly, there were no significant differences in the LOS (MD: -0.55; 95% CI: − 2.28, 1.18; p = 0.53), 30-day readmission (12.1% vs. 14.3%; OR: 1.09; 95% CI: 0.67–1.77; p = 0.73), and 30-day mortality (3.2% vs. 2.1%; OR: 1.34; 95% CI: 0.66–2.69; p = 0.42). The quality of evidence was very low.

Conclusions

The geriatric care models involved pre-operative comprehensive geriatric assessment, and intervention tools to address cognition, frailty, and functional status. In non-cardiac high-risk surgeries, these care models did not show any significant difference in the prevalence of delirium, LOS, 30-days readmission rates, and 30-day mortality in geriatric patients. Further RCTs are warranted to evaluate these models on the postoperative outcomes.

Trial registration

PROSPERO registration number - CRD42020181779.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01337-2.

Post-operative delirium in older hip fracture patients: a new onset or was it already there?

PURPOSE

Hip fractures are a worldwide health issue primarily for older patients, conditioning major morbidity and mortality. An experienced multidisciplinary team is essential to manage surgery and peri-operative implications, to enable rapid functional and cognitive recovery. Delirium is a recognizable problem associated with negative outcomes. Our study aims to determine the influence of pre-operative delirium in the incidence of post-operative delirium, and to evaluate the association between other known peri-operative risk factors with both conditions.

METHODS

A single-center, retrospective cohort study, conducted at a Level II trauma center over a 14-month period, included 241 patients with 65 years of age or older submitted to hip fracture surgery. Peri-operative data were gathered regarding baseline characteristics (sociodemographic, functional and cognitive status), intra-operative events (anesthesia technique, surgery duration, blood loss) and post-operative outcomes (delirium occurrence).

RESULTS

Statistical analysis evidenced a female (75.5%) and elderly population (83.9 ± 7.8 years old) with significant comorbidities (cognitive impairment in 51.9%, ASA ≥ III in 79.7%, mean CIRS-G 8.83 ± 4.69) that underwent surgical fracture repair, mostly under 4 h (96.3%) and under regional anesthesia (63.1%). Pre- and post-operative delirium incidence was 18.3% and 12.9%, respectively, displaying increased presence according to cognitive impairment severity.

CONCLUSION

Post-operative delirium was almost inexistent when it was absent pre-operatively. Moreover, pre-operative cognitive status was associated with the development of pre- and post-operative delirium. Careful cognitive assessment, implementation of preventive strategies and avoidance of peri-operative pro-delirium factors are crucial for comprehensive geriatric care.

Neuroanesthesiology Update

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function.

Institution of Monthly Anesthesia Quality Reports Does Not Reduce Postoperative Complications despite Improved Metric Compliance

While quality programs have been shown to improve provider compliance, few have demonstrated conclusive improvements in patient outcomes. We hypothesized that there would be increased metric compliance and decreased postoperative complications after initiation of an anesthesiology quality improvement program at our institution. We performed a retrospective study of all adult inpatients having anesthesia for a twelve-month period that spanned six months before and after program implementation. The primary outcome was the rate of complications in the post-implementation period. Secondary outcomes included the change in proportion of complications and compliance with quality metrics. We studied a total of 9620 adult inpatient cases, subdivided into pre- and post-implementation groups (4832 vs 4788.) After multivariate model adjustment, the rate of any complication (our primary outcome) was not significantly changed (32% to 31%; adjusted P = 0.410.) Of the individual complications, only wound infection (2.0% to 1.5%; adjusted P = 0.020) showed a statistically significant decrease. Statistically and clinically significant increases in compliance were seen for the BP-02 Avoiding Monitoring Gaps metric (81% to 93%, P < 0.001), both neuromuscular blockade metrics (NMB-01 76% to 91%, P < 0.001; NMB-02 95% to 97%, P = 0.006), both tidal volume metrics (PUL-01 84% to 93%, P < 0.001; PUL-02 30% to 45%, P < 0.001), and the TEMP-02 Core Temperature Measurement metric (88% to 94%, P < 0.001). Implementation of a comprehensive quality feedback program improved metric compliance but was not associated with a change in postoperative complications.