Association between postoperative delirium and postoperative cerebral oxygen desaturation in older patients after cardiac surgery

Effect of oxygen delivery during cardiopulmonary bypass on postoperative neurological outcomes in patients undergoing cardiac surgery: A scoping review of the literature

BACKGROUND

Reduced oxygen delivery (DO2) during cardiopulmonary bypass (CPB) was proposed as a risk factor for the development of postoperative neurological complications (PONCs), including cerebrovascular accidents (CVA), delirium, and postoperative cognitive dysfunction (POCD). We aimed to review the current evidence on the association between intraoperative DO2 and the incidence of PONCs.

METHODS

MEDLINE, Embase, the Cochrane Library, and Web of Science were electronically searched to identify comparative studies from inception until July 2023 that reported the association between intraoperative DO2 levels and the incidence of PONCs (as defined by the scales and diagnostic tools utilized by the studies' authors) in adults patients undergoing cardiac surgery using CPB.

RESULTS

Of the 2513 papers identified, 10 studies, including 21,875 participants, were included. Of these, three studies reported on delirium, two on POCD, and five on CVA. Eight studies reported reduced intraoperative DO2 in patients who developed delirium and CVA. There was a lack of consensus on the cut-off of DO2 levels or the correlation between the period below these threshold values and the development of PONC.

CONCLUSIONS

Limited data suggest that maintaining intraoperative DO2 above the critical threshold levels and ensuring adequate intraoperative cerebral perfusion may play a role in minimizing the incidence of neurological events in adult patients undergoing cardiac surgery on cardiopulmonary bypass.

Association between periprocedural cerebral desaturation during transcatheter aortic valve implantation and postprocedural delirium: a prospective observational study

BACKGROUND

The aim of this study was to investigate whether the level of decrease in cerebral oxygen saturation during the valve placement phase of the transcatheter aortic valve implantation (TAVI) procedure under sedation has an effect on postoperative delirium (POD).

METHODS

The study initially assessed 50 patients between the ages of 50 and 90 years with an indication for TAVI by the cardiac team. Regional cerebral oxygen saturation (rScO2) was measured using Near-infrared spectroscopy (NIRS) before the procedure (T1), during surgical field sterilization (T2), catheter placement (T3), wire manipulation (T4), valve placement (T5) and access site artery repair (T6). Confusion Assessment Method for The Intensive Care Unit (ICU-CAM) test was performed on intensive care unit and the presence of POD was questioned. Patients were divided into two groups as those without POD (Group 1) and those with POD (Group 2).

RESULTS

The study was completed with 41 patients in total. While POD was present in 12 (29.3%) of the patients evaluated intensive care unit, POD was not observed in 29 (70.7%) patients. The rScO2 value measured at T5 was significantly lower in Group 2 compared to Group 1 (p < 0.001).

CONCLUSIONS

In our study, the rate of POD after TAVI was as high as 29.3%. Low rScO2 during valve placement was associated with delirium. Our findings indicate that NIRS devices could be a useful tool for assessing the risk of POD during the TAVI procedure; however, further research is needed to validate their routine clinical use.

Anesthesia-induced electroencephalogram oscillations and perioperative outcomes in older adults undergoing cardiac surgery

BACKGROUND

Electroencephalogram oscillations during general anesthesia may change as a function of cognitive and physical health. This study aimed to characterize associations between anesthesia-induced oscillations and postoperative outcomes in cardiac surgery patients over 60 years.

METHODS

This was a prespecified secondary data analysis from the Minimizing Intensive Care Unit Dysfunction with Dexmedetomidine-induced Sleep (MINDDS) study. Participants were admitted from home for elective cardiac surgery with cardiopulmonary bypass. The primary outcome was postoperative delirium obtained using the Confusion Assessment Method. Secondary outcomes were non-home discharge and 30-day readmission. The exposure of interest was alpha power measured during the maintenance phase of isoflurane-general anesthesia. Confounding cognitive and physical health variables were collected.

RESULTS

Of 394 participants in the MINDDS study, 302 had analyzable electroencephalograms. The incidence of postoperative delirium was 11.1 %. Odds of postoperative delirium decreased by 14 % for every decibel increase in alpha power (OR 0.86, 95 % CI: 0.78 to 0.95; P = 0.004). This finding was not significant in adjusted analysis (ORadj 0.92, 95 % CI: 0.81 to 1.03; P = 0.154). Non-home discharge setting findings were not associated with alpha power. The odds of 30-day readmission decreased by 20 % for every decibel increase in alpha power (ORadj 0.80, 95 % CI: 0.71 to 0.91; P < 0.001). Findings were conserved in exploratory and sensitivity analyses.

CONCLUSIONS

In this study anesthesia-induced oscillations were associated with postoperative outcomes; however, these were not independently associated with delirium or discharge disposition after considering preoperative cognitive and physical health. These oscillations were robustly associated with 30-day readmission however, which may help anesthesiologists identify high-risk patients, offering benefits beyond the operating room.

CLINICAL TRIAL REGISTRATION

Registration Number: NCT02856594.

Regional cerebral oxygen saturation during initial mobilization of critically ill patients is associated with clinical outcomes: a prospective observational study

BACKGROUND

Vital signs help determine the safety of early mobilization in critically ill patients in intensive care units. However, none of these variables directly assess cerebral circulation. Therefore, we aimed to investigate the relationship of regional cerebral oxygen saturation (rSO2) and vital signs with in-hospital death in critically ill patients.

METHODS

This prospective study included critically ill patients admitted to the Uonuma Kikan Hospital Emergency Center who received physical therapy between June 2020 and December 2022. We continuously measured rSO2 during the initial mobilization using a wearable brain near-infrared spectroscopy device. With in-hospital death as the primary endpoint, the association between rSO2 and in-hospital death was assessed in Analysis 1 to determine the rSO2 cut-off value that predicts in-hospital death. In Analysis 2, patients were categorised into survival and non-survival groups to examine the temporal changes in vital signs and rSO2 associated with postural changes during mobilization.

RESULTS

Of the 132 eligible patients, 98 were included in Analysis 1, and 70 were included in Analysis 2. Analysis 1 demonstrated that lower premobilization rSO2 was independently associated with in-hospital death (odds ratio 0.835, 95% confidence interval 0.724-0.961, p = 0.012). Receiver operating characteristic curve analysis identified an optimal rSO2 cut-off value of 57% for predicting in-hospital death (area under the curve 0.818, sensitivity 73%, specificity 83%). Analysis 2 showed that rSO2 changes during mobilization were unrelated to changes in vital signs, suggesting rSO2 as an independent prognostic marker.

CONCLUSIONS

The results suggest that rSO2 measured during initial mobilization is associated with in-hospital death in critically ill patients.

Perioperative Near Infrared Spectroscopy Measurements of Cerebral Regional Oxygen Desaturations Are Not Associated With Delirium After Cardiac Surgery

OBJECTIVE

Postoperative delirium remains a common complication after cardiac surgery in high-risk patients and has been associated with prolonged intensive care unit length of stay, overall morbidity, and mortality. It has been proposed that cerebral hypoperfusion is an important etiological component. In the present study, we retrospectively queried intraoperative near-infrared spectroscopy measurements of regional cerebral oxygen saturations (rSO2) during adult cardiac surgical procedures to examine the association between rSO2 desaturations and postoperative delirium.

DESIGN

Retrospective observational cross-sectional study.

SETTING

Single tertiary care institution.

PARTICIPANTS

Patients aged 18 and older undergoing cardiac or open ascending thoracic aortic surgery from January 2016 through April 2023 were eligible; 3,696 patients were included in the analysis.

MEASUREMENTS AND MAIN RESULTS

As per departmental protocol, bilateral rSO2 probes were applied to the patients' forehead before induction of anesthesia. The first 5 minutes of rSO2 measurements were averaged and used as their baseline measurements. The total intraoperative duration of rSO2 measurements that were either 20% below baseline or below an absolute value of 50% and the total time in either category were determined. Postoperative delirium was assessed using the Confusion Assessment Method for Intensive Care Unit during the postoperative period. Age, cerebral vascular disease, preoperative cognitive impairment, dexmedetomidine use, and durations of cardiopulmonary bypass and bispectral index values less than 40 were associated with delirium. Neither baseline rSO2 nor any of the perioperative rSO2 desaturation incidences or durations were associated with postoperative delirium.

CONCLUSIONS

Neither baseline nor intraoperative near-infrared spectroscopy-measured cerebral rSO2 parameters were associated with postoperative delirium. Additional future studies are necessary to further define the value of perioperative cerebral rSO2 monitoring for the prevention of delirium after cardiac surgery.

The association between preoperative lacunar infarcts and postoperative delirium in elderly patients undergoing major abdominal surgery: a prospective cohort study

OBJECTIVE

The primary goal was to investigate whether the presence of preoperative lacunar infarcts (LACI) was associated with postoperative delirium (POD) in elderly patients undergoing elective major abdominal surgery.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

Patients aged ≥ 65 years from a tertiary level A hospital in China.

METHODS

The POD was assessed once daily within the first postoperative 3 days using the Confusion Assessment Method. Neurocognitive tests using the Mini-mental State Examination (MMSE) and the Beijing version of the Montreal Cognitive Assessment scales were carried out within 3 days before surgery and 4-7 days after surgery. Regional cerebral oxygen saturation (rScO2) was recorded in the operating room. Logistic regression analysis was used to evaluate the impact of preoperative LACI on POD and to explore the risk factors for POD.

RESULTS

A total of 369 participants were analyzed, 161 in the preoperative LACI-positive group (P group), and 208 in the preoperative LACI-negative group (N group), respectively. The incidence of POD was 32.7% in our study. The incidence of POD was significantly higher in the P group than in the N group (39.1 vs 27.9%, risk ratio, 1.66; 95% CI 1.07-2.58; P = 0.022). Furthermore, the P group exhibited lower mean rScO2 values during the procedure (P < 0.001). In exploratory analysis, the advanced age (P = 0.005), sex (P = 0.038), and lower preoperative MMSE score (P = 0.019) were independent risk factors for POD in patients undergoing major abdominal surgery.

CONCLUSIONS AND IMPLICATIONS

Preoperative LACI was common, and constituted a risk factor for POD in older patients undergoing abdominal surgery. Despite the frequent subclinical nature, the preoperative LACI led to lower mean rScO2 during the procedure. These findings could help early identification of high-risk POD patients.

Intravenous lidocaine decreased oxygen-desaturation episodes induced by propofol-based sedation for gastrointestinal endoscopy procedures: a prospective, randomized, controlled trial

BACKGROUND

As a popularly used analgesic adjuvant, intravenous (IV) lidocaine could reduce the consumption of propofol in painless gastrointestinal (GI) endoscopy. However, whether IV lidocaine could affect the incidence of oxygen-desaturation episodes (ODE) during painless GI endoscopy is still unknown. Therefore, we tested the hypothesis that IV lidocaine could decrease the incidence of propofol-induced ODE and involuntary movements in patients during GI endoscopy.

METHODS

Three hundred twenty-two patients scheduled for GI endoscopy were randomly divided into lidocaine group and control group. After midazolam and sufentanil injection, a bolus of 1.5 mg/kg lidocaine was given and followed by continuous infusion of 4 mg/kg/h in lidocaine group, whereas the same volumes of saline solution in control group. Then, propofol was titrated to produce unconsciousness. The primary outcome was the incidence of ODE during the procedure. The secondary outcomes were the incidence of different degree of hypoxia and corresponding treatments and the involuntary body movements.

RESULTS

A total of 300 patients were finally included in the analysis, 147 patients in lidocaine group and 153 in control group. The incidence of ODE was 22% in lidocaine group and 39% in control group (OR:0.052; 95%CI: 0.284-0.889; P = 0.018). IV lidocaine also improved the occurrence of different degree of hypoxia (P = 0.017) and needed few treatments (P = 0.028). The incidence of involuntary body movements (14% vs 26%, P = 0.013) and adverse circulatory events was decreased by IV lidocaine.

CONCLUSIONS

IV lidocaine adjuvant to propofol-based sedation could reduce the incidence of oxygen-desaturation episodes and involuntary body movements, with fewer adverse circulatory events.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100053818. Registered on 30 November 2021.

The impact of threshold-loaded inspiratory muscle training and respiratory biofeedback on preserving inspiratory muscle strength and vital capacity after CABG: a randomized clinical trial

OBJECTIVES

Postoperative pulmonary complications (POPC) are common after cardiac surgeries such as coronary artery bypass grafting (CABG) and are influenced by factors including anesthesia and surgical trauma. Inspiratory muscle training (IMT) with visual biofeedback may mitigate these complications. This study investigates the impact of threshold loading inspiratory muscle training (TL-IMT) combined with respiratory biofeedback on the dynamic strength of inspiratory muscles (S-index) in patients undergoing CABG surgery during their hospitalization phase.

METHODS

A single-blind study was conducted with 38 CABG candidates at Shahid Modares Hospital, Tehran. Participants were randomized into two groups: the TL-IMT with biofeedback group and the placebo IMT group. TL-IMT exercises were performed at 30% of maximum dynamic inspiratory strength using the Power Breath K5 device, with visual biofeedback displayed on the screen. The placebo group performed the same exercises at minimal load without biofeedback. Both groups received standard respiratory physiotherapy. Measurements of S-index, peak inspiratory flow (PIF), and vital capacity (VC) were taken before surgery (T1), one day after surgery (T2), and at discharge (T3).

RESULTS

Both groups showed significant changes, with a decrease from T1 to T2 and an increase from T2 to T3. In the study group, T3 values remained the same as at T1, while the placebo IMT group experienced a significant decrease. After surgery, both groups had a drop in the S-index. However, the study group saw more pronounced changes between T3-T2 and T3-T1 compared to the control group, although no significant difference was found between T2-T1. By the time of discharge, the TL-IMT group had higher S-index values than the placebo group, returning to preoperative levels. Additionally, the TL-IMT group showed improvements in PIF and VC.

CONCLUSION

TL-IMT with visual biofeedback effectively maintains dynamic inspiratory muscle strength and improves key pulmonary parameters in cardiac surgery patients. These findings suggest that integrating TL-IMT with biofeedback can enhance postoperative recovery and reduce the incidence of POPC.

Clinical investigation into risk factors for delirium post-cardiac surgery and its implications for nursing intervention guided by behavior change theory

BACKGROUND

This study explores the factors contributing to the occurrence of delirium following cardiac surgery and devises nursing strategies rooted in behavior change theory.

METHODS

A cohort of 320 cardiac surgery patients was selected, categorized into two groups: 93 cases where postoperative delirium (POD) was anticipated, and 227 cases where it was not. Preoperative, intraoperative, and postoperative factors of POD were scrutinized using single-factor analysis, while binary logistic regression analysis was employed to pinpoint risk factors.

RESULTS

Among the 320 patients, 93 displayed POD symptoms post-surgery, yielding an incidence of 29.06%. Preoperative univariate analysis disclosed significant differences in gender, age, smoking, hypertension, and diabetes (P < 0.05). Intraoperatively, significant differences were noted in the American Society of Anesthesiologists (ASA) anesthesia grade (II, III, and IV), surgery time, cardiopulmonary bypass duration, and aortic occlusion duration (P < 0.05). Post-surgery, significant differences were observed in the duration of Intensive Care Unit (ICU) stay, mechanical ventilation time, and visual analogue scale (VAS) scores (P < 0.05). Multivariate Logistic regression identified surgery time (OR = 2.334, P < 0.001), ICU admission duration (OR = 1.457, P < 0.001), mechanical ventilation time (OR = 1.235, P = 0.004), and VAS scores (OR = 2.986, P < 0.001) as independent risk factors for POD. ROC curve analysis indicated higher sensitivity and specificity in predicting POD with surgery time, ICU stay duration, mechanical ventilation time, and VAS scores.

CONCLUSION

Irrespective of the surgical intervention type, surgery time, ICU stay duration, mechanical ventilation time, and VAS scores are recognized as risk factors for POD in cardiac surgery patients. Hence, continuous patient monitoring and early intervention tailored to specific risk factors are essential in clinical practice to mitigate POD incidence.

Risk factors for postoperative delirium in frail elderly patients undergoing on-pump cardiac surgery and development of a prediction model-a prospective observational study

Background

To identify the risk factors for postoperative delirium (POD) after cardiac surgery in frail elderly patients and develop a receiver operating characteristic (ROC) prediction model to confirm the effectiveness.

Methods

This was a prospective observational study, patients were assessed preoperatively according to the frailty index (FI) scale. Cerebral (SctO2) was assessed at different time points using near-infrared spectroscopy (NIRS). On the basis of the occurrence of POD within 7 days after surgery, patients were divided into POD and non-POD groups. Risk factors were analyzed using logistic regression analysis, while their predictive values were evaluated using the receiver operating characteristic curve analysis.

Results

POD was significantly associated with frailty, lower preoperative MMSE scores, hyperlipidemia, diabetes, cerebrovascular disease, lower hemoglobin level, lower albumin level, longer operation time, longer CPB time, lower SctO2 at T5, and lower SctO2baseline (P < 0.05). SrtO2 and SmtO2 did not differ significantly between groups. FI, preoperative MMSE score, and operation time as independent risk factors (P < 0.05). Significant predictive value was demonstrated in all 3 variables (P < 0.001; respectively). Among them, high sensitivity and specificity were observed with the FI (cut-off value 0.27, sensitivity 75%, specificity 73.5%) and operation time (cut-off value 237.5, sensitivity 62.5%, specificity 78.6%).

Conclusions

The FI, preoperative MMSE score, and operation time were independent risk factors for POD in elderly patients after cardiac surgery, with high predictive value observed with the FI and operation time. Cerebral oxygen saturation was associated with POD but was not an independent risk factor.

Clinical Trial Registration

Chinese Clinical Trail Registry, No: chictr2200056038.

Association of postoperative delirium with hypotension in critically ill patients after cardiac surgery: a prospective observational study

BACKGROUND

Postoperative delirium (POD), an acute and variable disturbance in cognitive function, is an intricate and elusive phenomenon that occurs after cardiac surgery. Despite progress in surgical techniques and perioperative management, POD remains a formidable challenge, imposing a significant burden on patients, caregivers, and healthcare systems.

METHODS

This prospective observational study involved 307 patients who underwent cardiac surgery. Data on the occurrence of delirium, clinical parameters, and postoperative characteristics were collected. A multivariate analysis was performed to assess the relationship between POH and POD.

RESULTS

Sixty-one patients (21%) developed delirium, with an average onset of approximately 5 days postoperatively and a duration of approximately 6 days. On multivariate analysis, POH was significantly associated with POD, and the adjusted odds ratios indicated that patients with POH were more likely to develop delirium (OR, 5.61; p = 0.006). Advanced age (OR, 1.11; p = 0.002), emergency surgery (OR, 8.31; p = 0.001), and on-pump coronary artery bypass grafting were identified as risk factors of POD. Patients who developed delirium were typically older, more likely to be male, and had higher morbidity rates than those who did not.

CONCLUSION

POH is significantly associated with delirium in critically ill patients after cardiac surgery. Surgical complexity and advanced age contribute to the risk of developing POD and poor postoperative outcomes.

Electrical impedance tomography provides information of brain injury during total aortic arch replacement through its correlation with relative difference of neurological biomarkers

Postoperative neurological dysfunction (PND) is one of the most common complications after a total aortic arch replacement (TAAR). Electrical impedance tomography (EIT) monitoring of cerebral hypoxia injury during TAAR is a promising technique for preventing the occurrence of PND. This study aimed to explore the feasibility of electrical impedance tomography (EIT) for warning of potential brain injury during total aortic arch replacement (TAAR) through building the correlation between EIT extracted parameters and variation of neurological biomarkers in serum. Patients with Stanford type A aortic dissection and requiring TAAR who were admitted between December 2021 to March 2022 were included. A 16-electrode EIT system was adopted to monitor each patient's cerebral impedance intraoperatively. Five parameters of EIT signals regarding to the hypothermic circulatory arrest (HCA) period were extracted. Meanwhile, concentration of four neurological biomarkers in serum were measured regarding to time before and right after surgery, 12 h, 24 h and 48 h after surgery. The correlation between EIT parameters and variation of serum biomarkers were analyzed. A total of 57 TAAR patients were recruited. The correlation between EIT parameters and variation of biomarkers were stronger for patients with postoperative neurological dysfunction (PND(+)) than those without postoperative neurological dysfunction (PND(-)) in general. Particularly, variation of S100B after surgery had significantly moderate correlation with two parameters regarding to the difference of impedance between left and right brain which were MRAIabs and TRAIabs (0.500 and 0.485 with p < 0.05, respectively). In addition, significantly strong correlations were seen between variation of S100B at 24 h and the difference of average resistivity value before and after HCA phase (ΔARVHCA), the slope of electrical impedance during HCA (kHCA) and MRAIabs (0.758, 0.758 and 0.743 with p < 0.05, respectively) for patients with abnormal S100B level before surgery. Strong correlations were seen between variation of TAU after surgery and ΔARVHCA, kHCA and the time integral of electrical impedance for half flow of perfusion (TARVHP) (0.770, 0.794 and 0.818 with p < 0.01, respectively) for patients with abnormal TAU level before surgery. Another two significantly moderate correlations were found between TRAIabs and variation of GFAP at 12 h and 24 h (0.521 and 0.521 with p < 0.05, respectively) for patients with a normal GFAP serum level before surgery. The correlations between EIT parameters and serum level of neurological biomarkers were significant in patients with PND, especially for MRAIabs and TRAIabs, indicating that EIT may become a powerful assistant for providing a real-time warning of brain injury during TAAR from physiological perspective and useful guidance for intensive care units.

Inhibited hypoxia-inducible factor by intraoperative hyperglycemia increased postoperative delirium of aged patients: A review

The underlying mechanism of postoperative delirium (POD) in elderly people remains unclear. Perioperative hyperglycemia (POHG) is an independent risk indicator for POD, particularly in the elderly. Under cerebral desaturation (hypoxia) during general anesthesia, hypoxia-inducible factor (HIF) is neuroprotective during cerebral hypoxia via diverse pathways, like glucose metabolism and angiogenesis. Hyperglycemia can repress HIF expression and activity. On the other hand, POHG occurred among patients undergoing surgery. For surgical stress, hypothalamic-pituitary-adrenal activation and sympathoadrenal activation may increase endogenous glucose production via gluconeogenesis and glycogenolysis. Thus, under the setting of cerebral hypoxia during general anesthesia, we speculate that POHG prevents HIF-1α levels and function in the brain of aged patients, thus exacerbating the hypoxic response of HIF-1 and potentially contributing to POD. This paper sketches the underlying mechanisms of HIF in POD in elderly patients and offers novel insights into targets for preventing or treating POD in the same way as POHG.

Association between pediatric postoperative delirium and regional cerebral oxygen saturation: a prospective observational study

BACKGROUND

Postoperative delirium (POD) represents a prevalent and noteworthy complication in the context of pediatric surgical interventions. In recent times, a hypothesis has emerged positing that cerebral ischemia and regional cerebral oxygen desaturation might serve as potential catalysts in the pathogenesis of POD. The primary aim of this study was to methodically examine the potential relationship between POD and regional cerebral oxygen saturation (rSO2) and to assess the predictive and evaluative utility of rSO2 in the context of POD.

METHODS

This prospective observational study was conducted at the Children's Hospital, Zhejiang University School of Medicine, Zhejiang, China, spanning the period from November 2020 to March 2021. The research cohort comprised children undergoing surgical procedures within this clinical setting. To measure rSO2 dynamics, cerebral near-infrared spectroscopy (NIRS) was used to monitor rSO2 levels both before and after surgery. In addition, POD was assessed in the paediatric patients according to the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) criteria. The analysis of the association between the rSO2 index and the incidence of POD was carried out through the application of either the independent samples t-test or the nonparametric rank-sum test. To ascertain the threshold value of the adjusted rSO2 index for predictive and evaluative purposes regarding POD in the pediatric population, the Receiver Operating Characteristics (ROC) curve was employed.

RESULTS

A total of 211 cases were included in this study, of which 61 (28.9%) developed POD. Participants suffering delirium had lower preoperative rSO2mean, lower preoperative rSO2min, and lower postoperative rSO2min, higher ∆rSO2mean, higher amount of ∆rSO2mean, lower ∆rSO2min (P < 0.05). Preoperative rSO2mean (AUC = 0.716, 95%CI 0.642-0.790), ∆rSO2mean (AUC = 0.694, 95%CI 0.614-0.774), amount of ∆rSO2mean (AUC = 0.649, 95%CI 0.564-0.734), preoperative rSO2min (AUC = 0.702, 96%CI 0.628-0.777), postoperative rSO2min (AUC = 0.717, 95%CI 0.647-0.787), and ∆rSO2min (AUC = 0.714, 95%CI 0.638-0.790) performed well in sensitivity and specificity, and the best threshold were 62.05%, 1.27%, 2.41%, 55.68%, 57.36%, 1.29%.

CONCLUSIONS

There is a close relationship between pediatric POD and rSO2. rSO2 could be used as an effective predictor of pediatric POD. It might be helpful to measure rSO2 with NIRS for early recognizing POD and making it possible for early intervention.

Lower alpha frequency of intraoperative frontal EEG is associated with postoperative delirium: A secondary propensity-matched analysis

BACKGROUND

Postoperative delirium (POD) is a serious complication of surgery, especially in the elderly patient population. It has been proposed that decreasing the amount of anesthetics by titrating to an EEG index will lower POD rate, but clear evidence is missing. A strong age-dependent negative correlation has been reported between the peak oscillatory frequency of alpha waves and end-tidal anesthetic concentration, with older patients generating slower alpha frequencies. We hypothesized, that slower alpha oscillations are associated with a higher rate of POD.

METHOD

Retrospective analysis of patients` data from a prospective observational study in cardiac surgical patients approved by the Bernese Ethics committee. Frontal EEG was recorded during Isoflurane effect-site concentrations of 0.7 to 0.8 and peak alpha frequency was measured at highest power between 6 and 17 Hz. Delirium was assessed by chart review. Demographic and clinical characteristics were compared between POD and non-POD groups. Selection bias was addressed using nearest neighbor propensity score matching (PSM) for best balance. This incorporated 18 variables, whereas patients with missing variable information or without an alpha oscillation were excluded.

RESULT

Of the 1072 patients in the original study, 828 were included, 73 with POD, 755 without. PSM allowed 328 patients into the final analysis, 67 with, 261 without POD. Before PSM, 8 variables were significantly different between POD and non-POD groups, none thereafter. Mean peak alpha frequency was significantly lower in the POD in contrast to non-POD group before and after matching (7.9 vs 8.9 Hz, 7.9 vs 8.8 Hz respectively, SD 1.3, p < 0.001).

CONCLUSION

Intraoperative slower frontal peak alpha frequency is independently associated with POD after cardiac surgery and may be a simple intraoperative neurophysiological marker of a vulnerable brain for POD. Further studies are needed to investigate if there is a causal link between alpha frequency and POD.

Risk factors for postoperative delirium in elderly patients undergoing heart valve surgery with cardiopulmonary bypass

BACKGROUND

The aim of this study was to identify the risk factors for postoperative delirium (POD) in elderly patients undergoing heart valve surgery with cardiopulmonary bypass (CPB).

METHODS

Elderly patients undergoing elective heart valve surgery with CPB in The First Affiliated Hospital of Wenzhou Medical University between March 2022 and March 2023 were selected for this investigation. They were divided into a POD group and a non-POD group. Their baseline information was collected and recorded, and the patients were subjected to neurocognitive function assessment using the Mini-Mental State Examination and the Montreal Cognitive Assessment scales before surgery. We also recorded their intraoperative indicators such as duration of surgery, duration of CPB, duration of aortic cross-clamp, blood transfusion, and postoperative indicators such as duration of mechanical ventilation, postoperative 24-hour drainage volume, and pain score. Regional cerebral oxygen saturation was monitored intraoperatively by near-infrared spectroscopy based INVOS5100C Regional Oximeter. Patients were assessed for the occurrence of POD using Confusion Assessment Method for the Intensive Care Unit, and logistic regression analysis of risk factors for POD was performed.

RESULTS

The study finally included 132 patients, with 47 patients in the POD group and 85 ones in the non-POD group. There were no significant differences in baseline information and preoperative indicators between the two groups. However, marked differences were identified in duration of surgery, duration of CPB, duration of aortic cross-clamp, duration of postoperative mechanical ventilation, postoperative length of stay in cardiac intensive care unit, postoperative length of hospital stay, intraoperative blood transfusion, postoperative pain score, and postoperative 24-hour drainage volume between the two groups (p < 0.05). Additionally, the two groups had significant differences in rScO2 at each intraoperative time point and in the difference of rScO2 from baseline at each intraoperative time point (p < 0.05). Multivariate logistic regression analysis showed that duration of surgery > 285 min (OR, 1.021 [95% CI, 1.008-1.035]; p = 0.002), duration of postoperative mechanical ventilation > 23.5 h (OR, 6.210 [95% CI, 1.619-23.815]; p = 0.008), and postoperative CCU stay > 3.5 d (OR, 3.927 [95% CI, 1.046-14.735]; p = 0.043) were independent risk factors of the occurrence of POD while change of rScO2 at T1>50.5 (OR, 0.832 [95% CI 0.736-0.941]; p = 0.003) was a protective factor for POD.

CONCLUSION

Duration of surgery duration of postoperative mechanical ventilation and postoperative CCU stay are risk factors for POD while change of rScO2 at T1 is a protective factor for POD in elderly patients undergoing heart valve surgery with CPB.

Communication Regarding the Myocardial Ischemia/Reperfusion and Cognitive Impairment: A Narrative Literature Review

Coronary artery disease is a prevalent ischemic disease that results in insufficient blood supply to the heart muscle due to narrowing or occlusion of the coronary arteries. Various reperfusion strategies, including pharmacological thrombolysis and percutaneous coronary intervention, have been developed to enhance blood flow restoration. However, these interventions can lead to myocardial ischemia/reperfusion injury (MI/RI), which can cause unpredictable complications. Recent research has highlighted a compelling association between MI/RI and cognitive function, revealing pathophysiological mechanisms that may explain altered brain cognition. Manifestations in the brain following MI/RI exhibit pathological features resembling those observed in Alzheimer's disease (AD), implying a potential link between MI/RI and the development of AD. The pro-inflammatory state following MI/RI may induce neuroinflammation via systemic inflammation, while impaired cardiac function can result in cerebral under-perfusion. This review delves into the role of extracellular vesicles in transporting deleterious substances from the heart to the brain during conditions of MI/RI, potentially contributing to impaired cognition. Addressing the cognitive consequence of MI/RI, the review also emphasizes potential neuroprotective interventions and pharmacological treatments within the MI/RI model. In conclusion, the review underscores the significant impact of MI/RI on cognitive function, summarizes potential mechanisms of cardio-cerebral communication in the context of MI/RI, and offers ideas and insights for the prevention and treatment of cognitive dysfunction following MI/RI.

Influence of Regional Nerve Block in Addition to General Anesthesia on Postoperative Delirium, Pain, and In-hospital Stay in Patients Undergoing Cardiothoracic Surgery: A Meta-analysis

ABSTRACT

This study aims to investigate whether venous injection of sedative agent or regional nerve block in alliance with major anesthesia could decrease the risk of postoperative delirium occurrence in patients receiving cardiothoracic surgery. Electronic academic databases were retrieved for related publications, and statistical software was used for data pooling and analysis. Forest plot was used to show the pooled sensitivity, specificity, and diagnostic odds ratio. Combined receiver operating characteristic curve was used to show the area under the curve of complex data. Seven studies were included for analysis. The risk of occurrence of delirium still showed no difference (risk rate = 0.93, 95% CI, 0.85-1.03) between the intervention group and placebo group. Postoperative pain feeling was more alleviated in patients with prophylactic application of regional nerve block. In addition, prophylactic application of regional nerve block could decrease the risk of postoperative in-hospital stay (risk rate = 0.28, 95% CI, 0.02-0.54). Our study demonstrated that, in elderly patients or pediatric patients undergoing cardiac surgery, prophylactic application of regional nerve block failed to decrease the incidence of postoperative delirium. However, the option of regional nerve block could decrease the duration of in-hospitalization stay and alleviate the acute pain during the postoperative period after open-heart surgery.

Research progress of postoperative cognitive dysfunction in cardiac surgery under cardiopulmonary bypass

Cardiopulmonary bypass (CPB) is often used in cardiothoracic surgery because its nonphysiological state causes pathophysiological changes in the body, causing multiorgan and multitissue damage to varying degrees. Postoperative cognitive dysfunction (POCD) is a common central nervous system complication after cardiac surgery. The etiology and mechanism of POCD are not clear. Neuroinflammation, brain mitochondrial dysfunction, cerebral embolism, ischemia, hypoxia, and other factors are related to the pathogenesis of POCD. There is a close relationship between CPB and POCD, as CPB can cause inflammation, hypoxia and reperfusion injury, and microemboli formation, all of which can trigger POCD. POCD increases medical costs, seriously affects patients' quality of life, and increases mortality. Currently, there is a lack of effective treatment methods for POCD. Commonly used methods include preoperative health management, reducing inflammation response during surgery, preventing microemboli formation, and implementing individualized rehabilitation programs after surgery. Strengthening preventive measures can minimize the occurrence of POCD and its adverse effects.

Perioperative Neurocognitive Disorders in Adults Requiring Cardiac Surgery: Screening, Prevention, and Management

Neurocognitive changes are the most common complication after cardiac surgery, ranging from acute postoperative delirium to prolonged postoperative neurocognitive disorder. Changes in cognition are distressing to patients and families and associated with worse outcomes overall. This review outlines definitions and diagnostic criteria, risk factors for, and mechanisms of Perioperative Neurocognitive Disorders and offers strategies for preoperative screening and perioperative prevention and management of neurocognitive complications.

Nighttime dexmedetomidine for delirium prevention in non-mechanically ventilated patients after cardiac surgery (MINDDS): A single-centre, parallel-arm, randomised, placebo-controlled superiority trial

BACKGROUND

The delirium-sparing effect of nighttime dexmedetomidine has not been studied after surgery. We hypothesised that a nighttime dose of dexmedetomidine would reduce the incidence of postoperative delirium as compared to placebo.

METHODS

This single-centre, parallel-arm, randomised, placebo-controlled superiority trial evaluated whether a short nighttime dose of intravenous dexmedetomidine (1 μg/kg over 40 min) would reduce the incidence of postoperative delirium in patients 60 years of age or older undergoing elective cardiac surgery with cardiopulmonary bypass. Patients were randomised to receive dexmedetomidine or placebo in a 1:1 ratio. The primary outcome was delirium on postoperative day one. Secondary outcomes included delirium within three days of surgery, 30-, 90-, and 180-day abbreviated Montreal Cognitive Assessment scores, Patient Reported Outcome Measures Information System quality of life scores, and all-cause mortality. The study was registered as NCT02856594 on ClinicalTrials.gov on August 5, 2016, before the enrolment of any participants.

FINDINGS

Of 469 patients that underwent randomisation to placebo (n = 235) or dexmedetomidine (n = 234), 75 met a prespecified drop criterion before the study intervention. Thus, 394 participants (188 dexmedetomidine; 206 placebo) were analysed in the modified intention-to-treat cohort (median age 69 [IQR 64, 74] years; 73.1% male [n = 288]; 26·9% female [n = 106]). Postoperative delirium status on day one was missing for 30 (7.6%) patients. Among those in whom it could be assessed, the primary outcome occurred in 5 of 175 patients (2.9%) in the dexmedetomidine group and 16 of 189 patients (8.5%) in the placebo group (OR 0.32, 95% CI: 0.10-0.83; P = 0.029). A non-significant but higher proportion of participants experienced delirium within three days postoperatively in the placebo group (25/177; 14.1%) compared to the dexmedetomidine group (14/160; 8.8%; OR 0.58; 95% CI, 0.28-1.15). No significant differences between groups were observed in secondary outcomes or safety.

INTERPRETATION

Our findings suggested that in elderly cardiac surgery patients with a low baseline risk of postoperative delirium and extubated within 12 h of ICU admission, a short nighttime dose of dexmedetomidine decreased the incidence of delirium on postoperative day one. Although non-statistically significant, our findings also suggested a clinical meaningful difference in the three-day incidence of postoperative delirium.

FUNDING

National Institute on Aging (R01AG053582).

A comprehensive review of cerebral oximetry in cardiac surgery

BACKGROUND

Patients who undergo cardiac surgery are at increased risk of stroke, postoperative cognitive decline, and delirium. These neurocognitive complications have led to increased costs, intensive care unit stays, morbidity, and mortality. As a result, there is a significant push to mitigate any neurological complications in cardiac surgery patients. Near-infrared spectroscopy to measure regional cerebral oxygen saturations has gained consideration due to its noninvasive and user-friendly nature. Cerebral oximetry desaturations during cardiac surgery have been linked to an array of adverse clinical outcomes. However, the most effective intraoperative interventions to protect this vulnerable patient population have yet to be ascertained.

AIM OF STUDY

To provide a comprehensive summary of the intraoperative management for cerebral oximetry desaturations during cardiac surgery. The review highlights clinical outcomes from cerebral oximetry use to quantify the importance of identifying cerebral desaturations during cardiac surgery. The review then interrogates possible interventions for cerebral oximetry desaturations in an effort to determine which interventions are most efficacious and to enlighten possible areas for further research.

METHODS

A narrative review of randomized controlled trials, observational studies, and systematic reviews with metanalyses was performed through August 2021.

RESULTS

There is significant heterogeneity among patient populations for which cerebral oximetry monitoring has been studied in cardiac surgery. Further, the definition of a clinically significant cerebral desaturation and the assessment of neurocognitive outcomes varied substantially across studies. As a result, metanalysis is challenging and few conclusions can be drawn. Cerebral oximetry use during cardiac surgery has not been associated with improvements in neurocognitive outcomes, morbidity, or mortality to date. The evidence to support a particular intervention for an acute desaturation is equivocal.

CONCLUSIONS

Future research is needed to quantify a clinically significant cerebral desaturation and to determine which interventions for an acute desaturation effectively improve clinical outcomes.

Which Predictor, SctO2 or SstO2, Is more Sensitive for Postoperative Cognitive Dysfunction in Spine Surgery: A Prospective Observational Study?

OBJECTIVE

Patients undergoing spinal surgery in the prone position may experience venous stasis, often resulting in edema in dependent areas of the body, including the head, and increased postoperative cognitive dysfunction (POCD). Not only does POCD present challenges for post-operative care and recovery, it can also cause permanent damage to the patient's brain and increase mortality and social costs. We aimed to clarify the incidence of POCD in patients with hypertension after prone spine surgery and to further determine the association between intraoperative somatic tissue oxygen saturation (SstO2)/cerebral tissue oxygen saturation (SctO2) and POCD.

METHODS

Patients with hypertension scheduled for open prone spine surgery from January 2020 to April 2021 were included in this single-center, prospective, observational study. SctO2 and SstO2 were monitored by near-infrared spectroscopy continuously throughout the surgery. The primary outcome was POCD assessed using the Mini-Mental Status Examination (MMSE). The association of SstO2 and SctO2 with POCD was evaluated with unadjusted analyses and multivariable logistic regression.

RESULTS

One hundred and one of 112 identified patients were included, 28 (27.8%) of whom developed POCD. None of the investigated SctO2 indices were predictive of POCD. However, the patients with POCD had greater decreases in intraoperative absolute SstO2 and relative SstO2 than the patients without POCD (P = 0.037, P = 0.036). Moreover, three SstO2 indices were associated with POCD, including a greater absolute SstO2 decrease (P = 0.021), a greater relative SstO2 decrease (P = 0.032), and a drop below 90% of the baseline SstO2 (P = 0.002), independent of ASA III status, preoperative platelets and postoperative sepsis. In addition, there was no correlation between intraoperative SctO2 and intraoperative SstO2 or between their respective absolute declines.

CONCLUSION

Twenty-eight (27.7%) of 101 patients developed POCD in patients with hypertension undergoing prone spine surgery, and intraoperative SstO2 is associated with POCD, whereas SctO2 shows no association with POCD. This study may initially provide a valuable new approach to the prevention of POCD in this population.

Early alteration of peripheral blood lymphocyte subsets as a risk factor for delirium in critically ill patients after cardiac surgery: A prospective observational study

Objective

There is a high incidence of delirium among patients with organ dysfunction undergoing cardiac surgery who need critical care. This study aimed to explore the risk factors for delirium in critically ill patients undergoing cardiac surgery and the predictive value of related risk factors.

Methods

We conducted a prospective observational study on adult critically ill patients who underwent cardiac surgery between January 2019 and August 2021. Patients were consecutively assigned to delirium and non-delirium groups. Univariate analysis and multivariate logistic analysis were used to determine the risk factors for delirium. Receiver operating characteristic curves and a nomogram were used to identify the predictive value of related risk factors.

Results

Delirium developed in 242 of 379 (63.9%) participants. Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores were 14.2 ± 5.6 and 18 ± 8.4, respectively. Patients with delirium had longer cardiopulmonary bypass time (149.6 ± 59.1 vs. 126.7 ± 48.5 min, p < 0.001) and aortic cross-clamp time (98.7 ± 51.5 vs. 86.1 ± 41.6 min, p = 0.010) compared with the non-delirium group. The area under the curve was 0.824 for CD4⁺ T cell count and 0.862 for CD4/CD8 ratio. Multivariate analysis demonstrated that age [odds ratio (OR) 1.030, p = 0.038], duration of physical restraint (OR 1.030, p < 0.001), interleukin-6 (OR 1.001, p = 0.025), CD19⁺ B cell count (OR 0.996, p = 0.016), CD4⁺ T cell count (OR 1.005, p < 0.001) and CD4/CD8 ratio (OR 5.314, p < 0.001) were independent risk factors for delirium. A nomogram revealed that age, cardiopulmonary bypass duration, CD4⁺ T cell count and CD4/CD8 ratio were independent predictors of delirium.

Conclusion

Age, duration of physical restraint, CD4⁺ T cell count and CD4/CD8 ratio were reliable factors for predicting delirium in critically ill patients after cardiac surgery. The receiver operating characteristic curves and nomogram suggested a potential role for CD4⁺ T cells in mediating potential neuroinflammation of delirium.

Goal-directed therapy based on rScO2 monitoring in elderly patients with one-lung ventilation: a randomized trial on perioperative inflammation and postoperative delirium

Background

The incidence of postoperative delirium (POD) is high in elderly patients with one-lung ventilation, which is mostly related to the impairment of cerebral oxygen supply/demand balance during operation. (Surgical) stress can cause changes to normal physiological function and increase oxygen supply to the brain. When cerebral oxygen supply/demand is unbalanced, other organs may have already suffered from hypoperfusion or even hypoxic damages leading to increased release of inflammatory factors. Regional saturation of cerebral oxygenation (rScO₂) monitoring can noninvasively monitor the variation of regional cerebral oxygen supply/demand balance in real time, and it has a good correlation with the occurrence of POD. S-100β is one of the markers commonly used to predict and diagnose POD, and lactate is one of the important indicators for the quality of tissue perfusion. The study explores whether the goal-directed therapy based on rScO₂ monitoring can reduce perioperative inflammatory factor levels and POD incidence in elderly patients with one-lung ventilation and improve tissue perfusion.

Methods

The study is registered on Chinese Clinical Trial Registry (ChiCTR2100054888). A total of 159 patients scheduled for thoracoscopic lobectomy under general anesthesia were divided into the control group (n = 81) and the goal-directed therapy group (GDT group, n = 78). On the basis of the conventional management in the control group, the GDT group applied goal-directed rScO₂ monitoring to maintain rScO₂ at ±20% baseline level during one-lung ventilation. The levels of interleukin-1β, interleukin-6, tumor necrosis factor-α, and lactate; the intensity of postoperative pain; and the incidence of POD before anesthesia (T1), at the end of operation (T2), on day 1 after operation (T3), on day 3 after operation (T4), and on day 7 after operation or before discharge (T5) were compared respectively between the two groups.

Results

The incidence of POD at T3 and the awakening time in the GDT group were lower than those in the control group (P < 0.05). During T2 to T4, the levels of inflammatory factors and lactate concentration in the control group were higher than those in the GDT group (P < 0.05). During T3 to T4, the levels of C-reactive protein and lactate in the control group were higher than those in the GDT group (P < 0.05). During T2 to T3, the levels of S-100β in the control group were higher than those in the GDT group (P < 0.05). The levels of inflammatory factors and lactate concentration in both groups during T2 to T4 were higher than those at T1 and T5 (P < 0.05), and there was no statistical difference at T1 versus T5 (P > 0.05). There was no significant difference in postoperative pain intensity, the incidence of agitation during awakening, and postoperative hospital stays between the two groups.

Conclusion

Goal-directed therapy based on rScO₂ monitoring can reduce perioperative inflammatory factor levels, postoperative delirium incidence, and postoperative awakening time and improve tissue perfusion in elderly patients with one-lung ventilation.

Trial registration

The Chinese Clinical Trial Registry ChiCTR2100054888. Registered on 28 December 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06654-6.

Delirium Development After Lung Transplantation: An Intraoperative Assessment

BACKGROUND

This study aimed to evaluate the relationship between intraoperative hemodynamic and laboratory parameters with postoperative delirium development after lung transplantation.

METHODS

A total of 77 patients who underwent lung transplantation in a single center were included in the study. Demographic and clinical data recorded at critical intraoperative stages (after induction [T1], after bilateral lungs are dissected [T2], while the patient is ventilated for 1 lung [T3], while the unilateral transplanted lung is ventilated [T4], while bilateral transplanted lungs are ventilated [T5], and after the thorax is closed [T6]), postoperative complications, mechanical ventilation duration, intensive care, and hospitalization durations and mortality rates were recorded.

RESULTS

A total of 83.1% of the 77 patients were male, and the mean (SD) age was 47.56 (12.95) years. The mean body mass index (calculated as weight in kilograms divided by height in meters squared) was 23.30 (3.99), and the median Charles Comorbidity Index (CCI) was 1. The diagnosis of 36.4% of the patients was chronic obstructive pulmonary disease. Delirium was seen in 51.9% of the patients. Age, CCI, intraoperative mean arterial pressure changes, lactate levels, mechanical ventilation duration, and hospital stay were all associated with delirium development.

CONCLUSION

Age, CCI, duration of mechanical ventilation, and hospital stay were independent predictors of postoperative delirium development. We believe that our study will be a guide for future prospective randomized controlled studies.

What is the impact of perioperative cerebral oxygen desaturation on postoperative delirium in old population: a systemic review and meta-analysis

BACKGROUND

Perioperative cerebral oxygen saturation (ScO₂) has been reported to associate with postoperative delirium (POD) which is a common postoperative complication, however, the results were inconclusive. Therefore, we aimed to conduct an up-to-date review and meta-analyze the relationship between perioperative ScO₂ and POD.

METHODS

We systematically searched PubMed, Embase and Web of science through January 13, 2022. The pooled results were estimated through a random-effects model meta-analysis and expressed as odds ratios (ORs) and standard mean differences (SMDs), accompanied with 95% confident intervals (CIs).

RESULTS

Finally, of 467 searched articles, ten articles were included. A total of six studies reported the baseline ScO₂ value and the pooled result showed that preoperative baseline ScO₂ was lower in POD groups (SMD = - 0.41, 95% CI - 0.64 to - 0.18). And beyond that, the pooled OR across four literatures about preoperative low ScO₂ on POD was 3.44 (95% CI 1.69, 7.02). In contrast, insignificant differences were detected in baseline/lowest ScO₂ value during intraoperative and postoperative period. Additionally, there were no statistically significant associations for intraoperative and postoperative low ScO₂ effect on POD risk. Meta-regress analysis has found no significant impact factors.

CONCLUSIONS

Based on current evidence, POD patients have a lower ScO₂, and ScO₂ desaturation may increase POD incidence, indicating the role of ScO₂ underlying pathological mechanisms. For generalizability of evidence, we should rely on high-quality, considering more comprehensively longitudinal, interdisciplinary studies.

The future of intensive care: delirium should no longer be an issue

In the ideal intensive care unit (ICU) of the future, all patients are free from delirium, a syndrome of brain dysfunction frequently observed in critical illness and associated with worse ICU-related outcomes and long-term cognitive impairment. Although screening for delirium requires limited time and effort, this devastating disorder remains underestimated during routine ICU care. The COVID-19 pandemic brought a catastrophic reduction in delirium monitoring, prevention, and patient care due to organizational issues, lack of personnel, increased use of benzodiazepines and restricted family visitation. These limitations led to increases in delirium incidence, a situation that should never be repeated. Good sedation practices should be complemented by novel ICU design and connectivity, which will facilitate non-pharmacological sedation, anxiolysis and comfort that can be supplemented by balanced pharmacological interventions when necessary. Improvements in the ICU sound, light control, floor planning, and room arrangement can facilitate a healing environment that minimizes stressors and aids delirium prevention and management. The fundamental prerequisite to realize the delirium-free ICU, is an awake non-sedated, pain-free comfortable patient whose management follows the A to F (A-F) bundle. Moreover, the bundle should be expanded with three additional letters, incorporating humanitarian care: gaining (G) insight into patient needs, delivering holistic care with a 'home-like' (H) environment, and redefining ICU architectural design (I). Above all, the delirium-free world relies upon people, with personal challenges for critical care teams to optimize design, environmental factors, management, time spent with the patient and family and to humanize ICU care.

The association between Monocyte-to-Lymphocyte ratio and postoperative delirium in ICU patients in cardiac surgery

Objective

To analyze the relationship between monocyte‐to‐lymphocyte ratio (MLR) and postoperative delirium (POD).

Methods

This cohort study was conducted in the Medical Information Mart for Intensive Care‐III (MIMIC‐III) version 1.4 database. MLR was measured according to the complete blood count. ICD‐9 was used to measure postoperative delirium. Multivariable logistic regression was utilized to examine the relationship between MLR and POD.

Results

Three thousand eight hundred sixty‐eight patients who had received cardiac surgery were retrospectively enrolled, including 2171 males and 1697 females, with a mean age of 63.9 ± 16.2 years. The univariate analysis suggested that high MLR (as a continuous variable) as associated with a 21% higher risk of POD (O R: 1.12, 95% CI, 1.02, 1.43, p = 0.0259), After adjustments for other confounding factors, gender, age, race, temperature, SBP, DBP, MAP, respiratory rate, SOFA, peripheral vascular disease, AG, psychoses, drug, and alcohol addiction, the results showed that high MLR (as a continuous variable) independently served as a risk factor for POD (OR: 1.21; 95% CI: 1.01–1.44; p = 0.0378). MLR was assessed as quintile and tertiles, high MLR was an independent risk factor for POD. In the subgroup analysis, there were no differences in MLR for patients with POD in pre‐specified subgroups.

Conclusions

Monocyte‐to‐lymphocyte ratio was a risk factor for POD. More research is necessary to thoroughly examine the function of MLR in POD.

Cerebral oximetry in adult cardiac surgery to reduce the incidence of neurological impairment and hospital length-of-stay: A prospective, randomized, controlled trial

BACKGROUND

Cerebral oximetry using near-infrared spectroscopy (NIRS) has been shown to reduce neurological dysfunction and hospital length-of-stay after adult cardiac surgery in some but not all studies. We audited maintaining cerebral saturations at or above baseline and showed improved neurological and length-of-stay outcomes. Our hypothesis for this study was that our NIRS protocol would improve neurological and length-of-stay outcomes.

METHODS

This prospective, single centre, double-blinded controlled study randomized 182 consecutive patients, scheduled for cardiac surgery using cardiopulmonary bypass. Participants were randomized by concealed envelope prior to anaesthesia. NIRS study group were managed perioperatively using our NIRS protocol of 8 interventions, increase cardiac output, normocapnia, increase mean arterial pressure, increase inspired oxygen, depth of anaesthesia, blood transfusion, correction of bypass cannula, change of surgical plan to restore levels equal to or above baseline. The control group had standard management without NIRS. Primary outcomes were neurological impairment (early and late) and hospital length-of-stay. Secondary outcomes were ventilation times, intensive care length-of-stay, major organ dysfunction and mortality.

RESULTS

91 patients entered each group. There was a significant improvement in self-reported six-month general functionality in the NIRS group (p = 0.016). Early neurological dysfunction and hospital length-of-stay was the same in both groups. Of the secondary outcomes only Intensive Care length-of-stay was statistically significant, being shorter in the NIRS group (p = 0.026).

CONCLUSION

Maintaining cerebral saturations above baseline reduces time spent in Intensive Care and may improve long term functional recovery but not stroke, major organ dysfunction and mortality.

Outcomes of a Delirium Prevention Program in Older Persons After Elective Surgery: A Stepped-Wedge Cluster Randomized Clinical Trial

Importance

Delirium significantly worsens elective surgery outcomes and costs. Delirium risk is highest in elderly populations, whose surgical health care resource consumption (50%) exceeds their demographic proportion (15% to 18%) in high-resource countries. Effective nonpharmacologic delirium prevention could safely improve care in these vulnerable patients, but data from procedure-specific studies are insufficiently compelling to drive changes in practice. Delirium prevention approaches applicable to different surgical settings remain unexplored.

Objective

To examine whether a multifaceted prevention intervention is effective in reducing postoperative delirium incidence and prevalence after various major surgical procedures.

Design, Setting, and Participants

This stepped-wedge cluster randomized trial recruited 1470 patients 70 years and older undergoing elective orthopedic, general, or cardiac surgery from November 2017 to April 2019 from 5 German tertiary medical centers. Data were analyzed from December 2019 to July 2021.

Interventions

First, structured delirium education was provided to clinical caregivers at each site. Then, the study delirium prevention team assessed patient delirium risk factors and symptoms daily. Prevention was tailored to individual patient needs and could include: cognitive, motor, and sensory stimulation; meal companionship; accompaniment during diagnostic procedures; stress relaxation; and sleep promotion.

Main Outcomes and Measures

Postoperative delirium incidence and duration.

Results

Of 1470 included patients, 763 (51.9%) were male, and the median (IQR) age was 77 (74-81) years. Overall, the intervention reduced postoperative delirium incidence (odds ratio, 0.87; 95% CI, 0.77-0.98; P = .02) and percentage of days with delirium (intervention, 5.3%; control, 6.9%; P = .03). The effect was significant in patients undergoing orthopedic or abdominal surgery (odds ratio, 0.59; 95% CI, 0.35-0.99; P = .047) but not cardiac surgery (odds ratio, 1.18; 95% CI, 0.70-1.99; P = .54).

Conclusions and Relevance

This multifaceted multidisciplinary prevention intervention reduced postoperative delirium occurrence and days with delirium in older patients undergoing different elective surgical procedures but not cardiac procedures. These results suggest implementing this delirium prevention program will improve care and outcomes in older patients undergoing elective general and orthopedic procedures.

Association between the reactivity of local cerebral oxygen saturation after hypo-to-hypercapnic tests and delirium after abdominal surgery in older adults: A prospective study

OBJECTIVE

This study aimed to investigate the correlation between changes in regional cerebral oxygen saturation (rSO2) and postoperative delirium in older adults undergoing major abdominal surgery.

MATERIALS AND METHODS

This prospective study enrolled older adults scheduled for elective major abdominal surgery at the Second Affiliated Hospital of Anhui Medical University from August 2021 to January 2022. The change in rSO2 from baseline was determined using the hypo-to-hypercapnic test. The main study outcome was the occurrence of postoperative delirium.

RESULTS

A total of 101 participants were included for analysis, of whom 16 (15.8%) developed postoperative delirium. Compared with non-delirium participants, the mean arterial pressure and heart rate were not significantly different in the postoperative delirium group at T0, T1, T2, T3, T4, and T6 (all P_interaction > 0.05), but the delirium group had lower pH, lower PaO2, and higher lactate levels at T4, T5, and T6 (all P_interaction < 0.05). rSO2 at T0, T1, T2, T3, T4, and T6 was 69.0 (63.2-75.2), 70.7 ± 7.3, 68.2 ± 7.5, 72.1 ± 8.0, 69.9 ± 7.8, 67.4 ± 7.2, and 71.7 ± 8.1, respectively. The postoperative change in rSO2 during the hypercapnia test (TΔrSO2%) was 6.62 (5.31-9.36). Multivariable analysis showed that the Cumulative Illness Rating Scale (odd ratio, OR = 1.89, 95% confidence interval, CI: 1.10-3.25, P = 0.021), preoperative albumin levels (OR = 0.67, 95% CI: 0.48-0.94, P = 0.022), rSO2 at T4 (OR = 0.61, 95% CI: 0.41-0.89, P = 0.010), and postoperative TΔrSO2% (OR = 0.80, 95% CI: 0.66-0.98, P = 0.028) were independently associated with postoperative delirium in older adults undergoing elective abdominal surgery.

CONCLUSION

The rSO2 measured at T4 and postoperative TΔrSO2% were independently associated with postoperative delirium in older adults undergoing elective abdominal surgery.

The use of cerebral oximetry in cardiac surgery: A systematic review and meta-analysis of randomized controlled trials

High prevalence of cerebral desaturation is associated with postoperative neurological complications in cardiac surgery. However, the evidence use of cerebral oximetry by correcting cerebral desaturation in the reduction of postoperative complications remains uncertain in the literature. This systematic review and meta-analysis aimed to examine the effect of cerebral oximetry on the incidence of postoperative cognitive dysfunction in cardiac surgery. Databases of MEDLINE, EMBASE, and CENTRAL were searched from their inception until April 2021. All randomized controlled trials comparing cerebral oximetry and blinded/no cerebral oximetry in adult patients undergoing cardiac surgery were included. Observational studies, case series, and case reports were excluded. A total of 14 trials (n = 2,033) were included in this review. Our pooled data demonstrated that patients with cerebral oximetry were associated with a lower incidence of postoperative cognitive dysfunction than the control group (studies = 4, n = 609, odds ratio [OR]: 0.15, 95% confidence interval [CI]: 0.04 to 0.54, P = 0.003, I² = 88%; certainty of evidence = very low). In terms of postoperative delirium (OR: 0.75, 95%CI: 0.50-1.14, P = 0.18, I² = 0%; certainty of evidence = low) and postoperative stroke (OR: 0.81 95%CI: 0.37-1.80, P = 0.61, I² = 0%; certainty of evidence = high), no significant differences (P > 0.05) were reported between the cerebral oximetry and control groups. In this meta-analysis, the use of cerebral oximetry monitoring in cardiac surgery demonstrated a lower incidence of postoperative cognitive dysfunction. However, this finding must be interpreted with caution due to the low level of evidence, high degree of heterogeneity, lack of standardized cognitive assessments, and cerebral desaturation interventions.

Cerebral monitoring in surgical ICU patients

PURPOSE OF REVIEW

To give an overview of cerebral monitoring techniques for surgical ICU patients.

RECENT FINDINGS

As the burden of postsurgical neurological and neurocognitive complications becomes increasingly recognized, cerebral monitoring in the surgical ICU might gain a relevant role in detecting and possibly preventing adverse outcomes. However, identifying neurological alterations in surgical ICU patients, who are often sedated and mechanically ventilated, can be challenging. Various noninvasive and invasive techniques are available for cerebral monitoring, providing an assessment of cortical electrical activity, cerebral oxygenation, blood flow autoregulation, intracranial pressure, and cerebral metabolism. These techniques can be used for the diagnosis of subclinical seizures, the assessment of sedation depth and delirium, the detection of an impaired cerebral blood flow, and the diagnosis of neurosurgical complications.

SUMMARY

Cerebral monitoring can be a valuable tool in the early detection of adverse outcomes in surgical ICU patients, but the evidence is limited, and clear clinical indications are still lacking.

Progress of research in postoperative cognitive dysfunction in cardiac surgery patients: A review article

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a common complication of central nervous system in middle-aged and elderly patients after cardiac surgery. The purpose of this study was to review the progress in diagnosis, pathogenesis and risk factors and control strategy of POCD.

METHODS

A systematic literature search was conducted using Pubmed and EMBASE, using the Mesh terms and key words "POCD", "diagnostic criteria", "pathogenesis", "influencing factors" and "prevention strategies". Studies were retained for review after meeting strict inclusion criteria that included only prospective studies evaluating risk factors for POCD in patients who had elective cardiac surgery. Diagnosis of POCD needed to be confirmed using the Diagnostic and Statistical Manual of Montreal Cognitive Assessment (MoCA) Scale and other criteria.

RESULTS

"Twenty two articles were selected for inclusion. The incidence of POCD across the studies ranged from 9% to 54%. Multiple factors have been associated with the pathogenesis and increased risk of POCD, including neuroinflammation, dysfunction of cholinergic system, abnormal protein function (β-amyloid), old age, anesthetic, surgical and other factors."

CONCLUSIONS

POCD is a common complication after cardiac surgery in elderly. The highest POCD incidence was observed after open aortic, TAVI and CABG surgery. Age, cognitive function, depression, CPB and anesthetic use are leading risk factors. Further research is needed in determining interventions that will be effective in preventing and treating POCD in cardiac surgical setting.

The Association Between Preoperative Frailty and Postoperative Delirium: A Systematic Review and Meta-analysis

PURPOSE

Identifying factors that place patients at high risk for developing postoperative delirium is an important first step to reduce incidence. Frailty is associated with poor postoperative outcomes. This meta-analysis aims to determine the association between preoperative frailty and postoperative delirium.

DESIGN

This is a systematic review and meta-analysis.

METHODS

We used PubMed, Scopus, Embase, CINAHL, Cochrane, and Web of Science as databases for the search up to April 23, 2020. We included cohort studies that assessed postoperative delirium as the outcome and described the prevalence of delirium among participants during the postoperative period. Odds ratio and 95% confidence interval were calculated to examine the association.

FINDINGS

Twenty cohort studies met our inclusion criteria, which included a total of 4,568 patients. We found that preoperative frailty was significantly associated with an increased risk of postoperative delirium (crude odds ratio: 3.28; 95% confidence interval: 2.51 to 4.28; I² = 46.7%) (adjusted odds ratio: 2.45; 95% confidence interval: 1.58 to 3.81; I² = 88.6%).

CONCLUSIONS

This meta-analysis showed that preoperative frailty is an independent risk factor for postoperative delirium. In patients undergoing cardiovascular surgery, there is a lower association between frailty and postoperative delirium. In patients with other types of surgery, preoperative frailty is closely related to postoperative delirium.

The Use of Cerebral Oximetry in Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The evidence on the use of cerebral oximetry during surgery to minimize postoperative neurologic complications remains uncertain in the literature. The present authors aimed to assess the value of cerebral oximetry in the prevention of postoperative cognitive dysfunction, postoperative delirium, and postoperative stroke in adults undergoing surgery.

DESIGN

A systematic review and meta-analysis.

SETTING

The surgery room.

PARTICIPANTS

Adult patients (ages ≥18 years) undergoing surgery.

INTERVENTIONS

Cerebral oximetry monitoring.

MEASUREMENTS AND MAIN RESULTS

Databases of Ovid MEDLINE, Ovid EMBASE, and CENTRAL were systematically searched from their inception until December 2020 for randomized controlled trials comparing cerebral oximetry monitoring with either blinded or no cerebral oximetry monitoring in adults undergoing surgery. Observational studies, case reports, and case series were excluded. Seventeen studies (n = 2,120 patients) were included for quantitative meta-analysis. Patients who were randomized to cerebral oximetry monitoring had a lower incidence of postoperative cognitive dysfunction (studies = seven, n = 969, odds ratio [OR] 0.23, 95% confidence interval [CI] 0.11-0.48, p = 0.0001; evidence = very low). However, no significant differences were observed in the incidence of postoperative delirium (studies = five, n = 716, OR 0.81, 95% CI 0.53-1.25, p = 0.35; evidence = high), and postoperative stroke (studies = seven, n = 1,087, OR 0.72, 95% CI 0.30-1.69, p = 0.45; evidence = moderate).

CONCLUSION

Adult patients with cerebral oximetry monitoring were associated with a significant reduction of postoperative cognitive dysfunction. However, given the low certainty of evidence and substantial heterogeneity, more randomized controlled trials using standardized assessment tools for postoperative cognitive dysfunction and interventions of correcting cerebral desaturation are warranted to improve the certainty of evidence and homogeneity.

Prolonged postoperative cerebral oxygen desaturation after cardiac surgery: A prospective observational study

BACKGROUND

Near-infrared spectroscopy (NIRS) is used routinely to monitor cerebral tissue oxygen saturation (SctO2) during cardiopulmonary bypass (CPB) but is rarely employed outside the operating room. Previous studies indicate that patients are at risk of postoperative cerebral oxygen desaturation after cardiac surgery.

OBJECTIVES

We aimed to assess perioperative and postoperative changes in NIRS-derived SctO2 in cardiac surgery patients.

DESIGN

Prospective observational study.

SETTING

The study was conducted in a tertiary referral university hospital in Australia from December 2017 to December 2018.

PATIENTS

We studied 34 adult patients (70.6% men) undergoing cardiac surgery requiring CPB and a reference group of 36 patients undergoing non-cardiac surgical procedures under general anaesthesia.

MAIN OUTCOME MEASURES

We measured SctO2 at baseline, during and after surgery, and then once daily until hospital discharge, for a maximum of 7 days. We used multivariate linear mixed-effects modelling to adjust for all relevant imbalances between the two groups.

RESULTS

In the cardiac surgery group, SctO2 was 63.7% [95% confidence interval (CI), 62.0 to 65.5] at baseline and 61.0% (95% CI, 59.1 to 62.9, P = 0.01) on arrival in the ICU. From day 2 to day 7 after cardiac surgery, SctO2 progressively declined. At hospital discharge, SctO2 was significantly lower than baseline, at 53.5% (95% CI, 51.8 to 55.2, P < 0.001). In the reference group, postoperative SctO2 was not significantly different from baseline. On multivariable analysis, cardiac surgery, peripheral vascular disease and time since the operation were associated with greater cerebral desaturation, whereas higher haemoglobin concentrations were associated with slightly better cerebral oxygenation.

CONCLUSION

After cardiac surgery on CPB, but not after non-cardiac surgery, most patients experience prolonged cerebral desaturation. Such postoperative desaturation remained unresolved 7 days after surgery. The underlying mechanisms and time to resolution of such cerebral desaturations require further investigation.

Preventing Delirium and Promoting Long-Term Brain Health: A Clinical Trial Design for the Perioperative Cognitive Enhancement (PROTECT) Trial

BACKGROUND

Perioperative neurocognitive disorders (PND), including postoperative delirium (POD), are common in older adults and, for many, precipitate functional decline and/or dementia.

OBJECTIVE

In this protocol, we describe a novel multidisciplinary, multicomponent perioperative intervention that seeks to prevent or reduce POD and associated cognitive decline.

METHODS

We will conduct a prospective, single-blind, pragmatic, randomized-controlled trial to compare our tailored multi-disciplinary perioperative pathway against current standard of care practices. We will recruit a total of 692 elective surgical patients aged 65 years or more and randomize them in a 1:1 design. Our perioperative intervention targets delirium risk reduction strategies by emphasizing the importance of early mobilization, nutrition, hydration, cognitive orientation, sensory aids, and avoiding polypharmacy. To promote healthy behavior change, we will provide a tailored psychoeducation program both pre- and postoperatively, focusing on cardiovascular and psychosocial risks for cognitive and functional decline.

RESULTS

Our primary outcome is the incidence of any PND (encapsulating POD and mild or major postoperative neurocognitive disorder) at three months postoperative. Secondary outcomes include any incidence of POD or neurocognitive disorder at 12 months. A specialized delirium screening instrument, the Confusion Assessment Method (3D-CAM), and a neuropsychological test battery, will inform our primary and secondary outcomes.

CONCLUSION

Delirium is a common and debilitating postoperative complication that contributes to the cognitive and functional decline of older adults. By adopting a multicomponent, multidisciplinary approach to perioperative delirium prevention, we seek to reduce the burden of delirium and subsequent dementia in older adults.

Association Between Cerebral Desaturation and Postoperative Delirium in Thoracotomy With One-Lung Ventilation: A Prospective Cohort Study

BACKGROUND

The association between cerebral desaturation and postoperative delirium in thoracotomy with one-lung ventilation (OLV) has not been specifically studied.

METHODS

A prospective observational study performed in thoracic surgical patients. Cerebral tissue oxygen saturation (Scto2) was monitored on the left and right foreheads using a near-infrared spectroscopy oximeter. Baseline Scto2 was measured with patients awake and breathing room air. The minimum Scto2 was the lowest measurement at any time during surgery. Cerebral desaturation and hypersaturation were an episode of Scto2 below and above a given threshold for ≥15 seconds during surgery, respectively. The thresholds based on relative changes by referring to the baseline measurement were <80%, <85%, <90%, <95%, and <100% baseline for desaturation and >105%, >110%, >115%, and >120% baseline for hypersaturation. The thresholds based on absolute values were <50%, <55%, <60%, <65%, and <70% for desaturation and >75%, >80%, >85%, and >90% for hypersaturation. The given area under the threshold (AUT)/area above the threshold (AAT) was analyzed. Delirium was assessed until postoperative day 5. The primary analysis was the association between the minimum Scto2 and delirium using multivariable logistic regression controlled for confounders (age, OLV time, use of midazolam, occurrence of hypotension, and severity of pain). The secondary analysis was the association between cerebral desaturation/hypersaturation and delirium, and between the AUT/AAT and delirium using multivariable logistic regression controlled for the same confounders. Multiple testing was corrected using the Holm-Bonferroni method. We additionally monitored somatic tissue oxygen saturation on the forearm and upper thigh.

RESULTS

Delirium occurred in 35 (20%) of 175 patients (65 ± 6 years old). The minimum left or right Scto2 was not associated with delirium. Cerebral desaturation defined by <90% baseline for left Scto2 (odds ratio [OR], 5.82; 95% confidence interval [CI], 2.12-19.2; corrected P =.008) and <85% baseline for right Scto2 (OR, 4.27; 95% CI, 1.77-11.0; corrected P =.01) was associated with an increased risk of delirium. Cerebral desaturation defined by other thresholds, cerebral hypersaturation, the AUT/AAT, and somatic desaturation and hypersaturation were all not associated with delirium.

CONCLUSIONS

Cerebral desaturation defined by <90% baseline for left Scto2 and <85% baseline for right Scto2, but not the minimum Scto2, may be associated with an increased risk of postthoracotomy delirium. The validity of these thresholds needs to be tested by randomized controlled trials.

Neuromonitoring and Neurocognitive Outcomes in Cardiac Surgery: A Narrative Review

Neurocognitive dysfunction after cardiac surgery can present with diverse clinical phenotypes, which include postoperative delirium, postoperative cognitive dysfunction, and stroke, and it presents a significant healthcare burden for both patients and providers. Neurologic monitoring during cardiac surgery includes several modalities assessing cerebral perfusion and oxygenation (near-infrared spectroscopy, transcranial Doppler and jugular venous bulb saturation monitoring) and those that measure cerebral function (processed and unprocessed electroencephalogram), reflecting an absence of a single, definitive neuromonitor. This narrative review briefly describes the technologic basis of these neuromonitoring modalities, before exploring their use in clinical practice, both as tools to predict neurocognitive dysfunction, and with a bundle of interventions designed to optimize cerebral oxygen supply, with the aim of reducing postoperative delirium and cognitive dysfunction following cardiac surgery.

Intraoperative Oxygen Concentration and Postoperative Delirium After Laparoscopic Gastric and Colorectal Malignancies Surgery: A Randomized, Double-Blind, Controlled Trial

Purpose

Postoperative delirium (POD) is common in elderly patients undergoing laparoscopic surgery for gastric and colorectal malignancies. POD may be affected by different fraction of inspired oxygen (FiO₂). The purpose of this study was to compare the effects of different FiO₂ on POD.

Patients and Methods

A randomized, double-blind controlled trial was performed in Qingdao Municipal Hospital Affiliated to Qingdao University. A total of 662 patients aged 65 to 85 years old underwent isolated laparoscopic radical gastrectomy, radical resection of colon cancer, or radical resection of rectal cancer only. A random number table method was used to divide the patients into two groups: 40% FiO₂ (group A) and 80% FiO₂ (group B). The primary endpoint was the incidence of POD, which was assessed by the Confusion Assessment Method (CAM) twice daily during the first 7 postoperative days, and POD severity was measured by the Memorial Delirium Assessment Scale (MDAS). The secondary endpoints were the intraoperative regional cerebral oxygen saturation (rSO₂), Bispectral (BIS) index, invasive arterial blood pressure (IABP), oxygen saturation (SpO₂), end-tidal carbon dioxide partial pressure (P_ETCO₂), the number of atelectasis cases and visual analogue scale (VAS) scores on days 1-7 after surgery.

Results

The incidence of POD was 19.37% (122/630), including 20.38% (64/314) in group A and 18.35% (58/316) in group B. No statistical significance was found in the incidence of POD between the two groups (P > 0.05); compared with group B, SpO₂, rSO₂ and PaO₂ decreased at T₂ to T₄ time point (P < 0.01), and the incidence of postoperative atelectasis decreased (P < 0.05) in group A.

Conclusion

The incidence of POD was not significantly affected by different FiO₂ and the incidence of postoperative atelectasis was decreased at low FiO₂.

Periinterventional inflammation and blood transfusions predict postprocedural delirium after percutaneous repair of mitral and tricuspid valves

Objectives

The aim of this study was to examine predictors and impact of postoperative delirium (POD) on outcome after percutaneous repair of mitral and tricuspid valves.

Background

POD is common in elderly patients and contributes to increased health care costs and worse outcome. Predictors of POD in percutaneous mitral or tricuspid valve procedures are unclear.

Methods

In a prospective single-center study, patients were screened for POD using the Confusion Assessment Method on the first and second postprocedural days, and up until 7 days in patients with clinical suspicion of delirium. Associations of POD with baseline characteristics, periprocedural outcome and mid-term mortality were examined.

Results

One hundred and seventy-seven patients were included (median age 78 years [72–82], 41.8% female) and median (IQR) follow-up was 489 (293–704) days. Patients developing POD (n = 16, 9%) did not differ in baseline and procedural characteristics but more often received postinterventional blood transfusions (37.5% vs. 9.9%, p value = 0.007) and suffered from infections (43.8% vs. 9.9%, p value = 0.001). Patients with POD showed worse survival (HR: 2.71 [1.27–5.78]; p = 0.01), with an estimated 1-year survival of 46 ± 13% compared to 80 ± 3% in patients without POD (log-rank p value 0.007). In multivariate Cox regression, POD remained a significant predictor of mid-term mortality (HR 4.75 [1.97–11.5]; p = 0.001).

Conclusion

After percutaneous mitral or tricuspid valve repair, POD was independently associated with worse mid-term survival. Procedure- rather than patient-associated characteristics such as blood transfusions and infections emerged as important risk factors for development of POD. Considering the substantial prognostic impact of POD, further studies on its prevention are warranted to improve patient outcome.