Effect of regional anesthesia on the postoperative delirium: A systematic review and meta-analysis of randomized controlled trials

The Impact of Regional Nerve Blocks on Postoperative Delirium or Cognitive Dysfunction following Thoracic Surgery: A Systematic Review and Meta-Analysis

Regional nerve blocks (NBs) mitigate the occurrence of postoperative cognitive dysfunction (POCD) and postoperative delirium (POD) in adult patients undergoing thoracic surgery. This study aimed to determine the exact effect of NBs on POCD and POD. Electronic databases, including PubMed, EMBASE, CINAHL, Scopus, and Web of Science, were searched for studies. The primary outcome was the incidence of POD or POCD. The secondary outcome was pain scores assessed 24 and 48 h postoperatively. We calculated the log odds ratio (LOR) and standardized mean difference (SMD) with 95% confidence intervals (CIs). The LOR was converted to an odds ratio (OR). In the analysis of 1010 patients from seven randomized controlled trials, POD and POCD rates were 14.1% and 16.7%, respectively, in the NB group, and higher, at 27.3% and 35.2%, in the control group. NBs reduced the incidence of POD (OR, 0.44; 95%CI 0.30 to 0.64; p < 0.001; I2 = 0.00%) and POCD (OR, 0.43; 95%CI 0.24 to 0.76; p < 0.001; I2 = 0.00%). NBs reduced pain scores at 24 h (SMD, -2.60; 95%CI -3.90 to -1.30, p < 0.001; I2 = 97.68%) and 48 h (SMD, -1.80; 95%CI -3.18 to -0.41, p = 0.01; I2 = 98.14%) postoperatively. NBs mitigated the occurrence of POD and POCD in adult patients after thoracic surgery.

Incidence and predictors of hemodynamic compromise due to high-grade AV block after TAVI

Background

High-grade AV block (HAVB) is the most frequent adverse event after transcatheter aortic valve implantation (TAVI). In rare cases, HAVB is associated with hemodynamic compromise (HC) followed by syncope or application of cardiopulmonary resuscitation (CPR), but data on this severe complication are scarce. The aim of the present study was to investigate the incidence and predictors of HC due to HAVB in patients undergoing TAVI.

Methods

In this retrospective analysis of 4,602 TAVI cases between 2010 and 2022, 466 developed HAVB. Baseline characteristics and procedural and postprocedural findings were compared for patients with HC versus those without. Univariate and multivariable regression analyses were used to investigate independent predictors of HC.

Results

Forty-nine of 466 patients (10.5%) had HC due to HAVB after TAVI. Patients with HC had a longer hospital stay [10 (8-13) vs. 13 (9-18) days; p < 0.001], more frequent peripheral artery disease (PAD) (28.6% vs. 15.1%; p = 0.016), and lower hemoglobin levels [11.8 (±) vs. 12.5 (±) g/dl; p = 0.006]. In the HC group, HAVB onset post-TAVI was delayed compared with the non-HC group [2 (1-4) vs. 1 (0-3) days; p < 0.001]. Before HAVB onset, patients in the HC group more frequently developed post-TAVI delirium [18 (4.6%) vs. 11 (25.0%); p < 0.001]. In univariate regression analysis, PAD, hemoglobin, procedural time, contrast agent volume, and post-TAVI delirium were significant predictors of HC. After adjustment, only post-TAVI delirium and contrast agent volume remained independent predictors [OR 3.22 (95% CI: 1.05-9.89); p = 0.042 and OR: 1.01 (95% CI: 1.0-1.01); p = 0.04, respectively].

Conclusion

HC due to HAVB after TAVI occurred in over 10% of cases. Development of post-TAVI delirium and contrast agent volume are independent predictors of this severe complication.

The Effect of Peripheral Nerve Block on Postoperative Delirium in Older Adults Undergoing Hip Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This meta-analysis aimed to determine whether peripheral nerve blocks (PNB) reduce postoperative delirium (POD) in elderly patients undergoing hip surgery. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022328320). The PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched for randomized controlled trials (RCTs) on 26 April 2022. A total of 19 RCTs with 1977 participants were included. Perioperative PNB lowered the POD incidence on the third postoperative day (OR: 0.59, 95% CI [0.40 to 0.87], p = 0.007, I² = 35%), in patients without underlying cognitive impairment (OR: 0.47, 95% CI [0.30 to 0.74], p = 0.001, I² = 30%), and when a fascia iliaca compartment block (OR: 0.58, 95% CI [0.37 to 0.91], p = 0.02, I² = 0%) or a femoral nerve block (OR: 0.33, 95% CI [0.11 to 0.99], p = 0.05, I² = 66%) were performed. The pain score was also reduced (SMD: -0.83, 95% CI [-1.36 to -0.30], p = 0.002, I² = 95%) after PNB. Perioperative PNB can lower the POD incidence and pain scores up to the third postoperative day. However, considering the wide variety of PNBs performed, more trials are needed to identify the effects of each PNB on POD.

Postoperative Delirium in Neurosurgical Patients: Recent Insights into the Pathogenesis

Postoperative delirium (POD) is a complication characterized by disturbances in attention, awareness, and cognitive function that occur shortly after surgery or emergence from anesthesia. Since it occurs prevalently in neurosurgical patients and poses great threats to the well-being of patients, much emphasis is placed on POD in neurosurgical units. However, there are intricate theories about its pathogenesis and limited pharmacological interventions for POD. In this study, we review the recent insights into its pathogenesis, mainly based on studies within five years, and the five dominant pathological theories that account for the development of POD, with the intention of furthering our understanding and boosting its clinical management.