Perioperative hyperglycemia is associated with postoperative neurocognitive disorders after cardiac surgery

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.

The Effect of Rhythmic Breathing on the Severity of Sternotomy Pain after Coronary Artery Bypass Graft Surgery: A Randomized Controlled Clinical Trial

Background

Moderate-to-severe pain is reported in up to 75% of the patients in the first 48 hours after cardiac surgery. Evidence suggests that distraction is an effective nursing intervention for controlling short-term and transient pain. Distraction can be achieved by various techniques, including progressive muscle relaxation, meditation, and rhythmic breathing (RB). The present research aimed at evaluating the impacts of RB on the severity of sternotomy pain after Coronary Artery Bypass Graft (CABG).

Methods

This randomized, controlled clinical trial was conducted on 60 patients after CABG surgery at the open-heart surgery Intensive Care Unit (ICU) of Kowsar Hospital, affiliated to Semnan University of Medical Sciences in Semnan, Iran. The patients were selected through convenience sampling and randomly assigned to two groups, including (1) intervention or RB and (2) control groups. RB was performed in the intervention group every 12 hours (9 a.m. and 9 p.m.) for three consecutive days after the surgery. The control group received only routine care for pain control (opioid analgesics) with no additional interventions. The severity of pain was measured every day in both groups of patients before and after the interventions using the Visual Analog Scale (VAS).

Results

The mean postintervention pain scores were significantly different from the mean preintervention scores in the intervention group (p < 0.05). The changes in the mean pain score in the intervention group were also significantly different from the corresponding changes in the controls (p < 0.05).

Conclusion

Based on the results, the severity of pain after the intervention was significantly lower in the RB group compared to the control. RB was found to be an effective technique for reducing the patients' pain and is therefore recommended as a post-CABG pain control technique. Iranian Registry of Clinical Trials: this trial is clinically registered with IRCT20120109008665N7, registered 3 September 2018.

Dysfunction of the Glymphatic System as a Potential Mechanism of Perioperative Neurocognitive Disorders

Perioperative neurocognitive disorder (PND) frequently occurs in the elderly as a severe postoperative complication and is characterized by a decline in cognitive function that impairs memory, attention, and other cognitive domains. Currently, the exact pathogenic mechanism of PND is multifaceted and remains unclear. The glymphatic system is a newly discovered glial-dependent perivascular network that subserves a pseudo-lymphatic function in the brain. Recent studies have highlighted the significant role of the glymphatic system in the removal of harmful metabolites in the brain. Dysfunction of the glymphatic system can reduce metabolic waste removal, leading to neuroinflammation and neurological disorders. We speculate that there is a causal relationship between the glymphatic system and symptomatic progression in PND. This paper reviews the current literature on the glymphatic system and some perioperative factors to discuss the role of the glymphatic system in PND.

Sevoflurane-induced hyperglycemia is attenuated by salsalate in obese insulin-resistant mice

PURPOSE

Perioperative hyperglycemia is common and is associated with significant morbidity. Although patient characteristics and surgery influence perioperative glucose metabolism, anesthetics have a significant impact. We hypothesized that mice that were obese and insulin-resistant would experience greater hyperglycemia in response to sevoflurane anesthesia compared with lean controls. We further hypothesized that sevoflurane-induced hyperglycemia would be attenuated by salsalate pre-treatment.

METHODS

Lean and obese male C57BL/6J mice were anesthetized with sevoflurane for 60 min with or without pre-treatment of 62.5 mg·kg^-1 salsalate. Blood glucose, plasma insulin, and glucose uptake into different tissues were measured.

RESULTS

Under sevoflurane anesthesia, obese mice had higher blood glucose compared to lean mice. Increases in blood glucose were attenuated with acute salsalate pre-treatment at 60 min under anesthesia in obese mice (mean ± standard error of the mean [SEM], delta blood glucose; vehicle 5.79 ± 1.09 vs salsalate 1.91 ± 1.32 mM; P = 0.04) but did not reach statistical significance in lean mice (delta blood glucose, vehicle 4.39 ± 0.55 vs salsalate 2.79 ± 0.71 mM; P = 0.10). This effect was independent of changes in insulin but associated with an approx. 1.7-fold increase in glucose uptake into brown adipose tissue (vehicle 45.28 ± 4.57 vs salsalate 76.89 ± 12.23 µmol·g^-1 tissue·hr^-1; P < 0.001).

CONCLUSION

These data show that salsalate can reduce sevoflurane-induced hyperglycemia in mice. This indicates that salsalate may represent a new class of therapeutics that, in addition to its anti-inflammatory and analgesic properties, may be useful to reduce perioperative hyperglycemia.

Effects of intravenous and inhalation anesthesia on blood glucose and complications in patients with type 2 diabetes mellitus: study protocol for a randomized controlled trial

Background

Diabetes mellitus (DM) is a metabolic disorder syndrome caused by relative or absolute lack of insulin and varying degrees of insulin resistance. The type and regimen of anesthesia may affect perioperative hyperglycemia following major surgical stress. The effect of perioperative anesthetics on the blood glucose level of diabetic patients will play an essential role in the postoperative recovery of patients. However, there is no rigorously-designed randomized controlled trial to compare the effects of total intravenous anesthesia (TIVA) and total inhalation anesthesia (TIHA) on blood glucose and complications in type 2 diabetes. Hence, we design this clinical trial to compare the effects of TIVA and TIHA of hyperglycemia and clinical outcomes in type 2 diabetes undergoing surgery.

Methods

This is a randomized, double-blind, parallel controlled trial. One hundred twelve patients with type 2 DM who meet the qualification criteria will be randomly divided into two groups: TIVA group and TIHA group. The levels of serum insulin and cortisol will be measured before and after the operation, and the levels of blood glucose at different setting time will be monitored. All patients will be followed up by blinded evaluators at baseline and 1, 3, 7, and 30 days after the intervention. The follow-up included postoperative complications [such as myocardial infarction (MI), stroke, renal failure, anastomotic fistula, stress ulcer, incision infection, lung infection] and adverse events.

Discussion

The routinely used clinical anesthesia schemes are TIVA, TIHA and intravenous-inhalation combined anesthesia. We expect that the results of this trial will provide high-quality clinical evidence for the choice of anesthesia options for patients with type 2 DM.

Trial registration

Chinese Clinical Trial Registry: ChiCTR2000029247, registration date: 20 January 2020.

MicroRNA339 Targeting PDXK Improves Motor Dysfunction and Promotes Neurite Growth in the Remote Cortex Subjected to Spinal Cord Transection

Spinal cord injury (SCI) is a fatal disease that can cause severe disability. Cortical reorganization subserved the recovery of spontaneous function after SCI, although the potential molecular mechanism in this remote control is largely unknown. Therefore, using proteomics analysis, RNA interference/overexpression, and CRISPR/Cas9 in vivo and in vitro, we analyzed how the molecular network functions in neurological improvement, especially in the recovery of motor function after spinal cord transection (SCT) via the remote regulation of cerebral cortex. We discovered that the overexpression of pyridoxal kinase (PDXK) in the motor cortex enhanced neuronal growth and survival and improved locomotor function in the hindlimb. In addition, PDXK was confirmed as a target of miR-339 but not miR-124. MiR-339 knockout (KO) significantly increased the neurite outgrowth and decreased cell apoptosis in cortical neurons. Moreover, miR-339 KO rats exhibited functional recovery indicated by improved Basso, Beattie, and Bresnehan (BBB) score. Furthermore, bioinformatics prediction showed that PDXK was associated with GAP43, a crucial molecule related to neurite growth and functional improvement. The current research therefore confirmed that miR-339 targeting PDXK facilitated neurological recovery in the motor cortex of SCT rats, and the underlying mechanism was associated with regulating GAP43 in the remote cortex of rats subjected to SCT. These findings may uncover a new understanding of remoting cortex control following SCI and provide a new therapeutic strategy for the recovery of SCI in future clinical trials.

Comparison of postoperative cognitive decline in patients undergoing conventional vs miniaturized cardiopulmonary bypass: A randomized, controlled trial

Background:

Neurocognitive dysfunction is a common complication of coronary artery bypass grafting (CABG) with incidence of 19–38%. The miniaturized cardiopulmonary bypass (MCPB) system was developed to reduce hemodilution and inflammation and provides better cerebral protection than conventional cardiopulmonary bypass (CCPB). In a meta-analysis, MCPB was associated with a 10-fold reduction in the incidence of strokes. However, its effect on postoperative cognitive decline (POCD) is unknown. We assessed if MCPB decreases POCD after CABG and compared the risk factors.

Methods:

A total of 71 Asian patients presenting for elective CABG at a tertiary center were enrolled. They were randomly assigned to MCPB (n = 36) or CCPB group (n = 35) and followed up in a single-blinded, prospective, randomized controlled trial. The primary outcome was POCD as measured by the repeatable battery of neuropsychological status (RBANS). Inflammatory markers (tumor necrosis factor-alpha and interleukin-6), hematocrit levels, and neutron-specific enolase (NSE) levels were studied.

Results:

Overall, the incidence of POCD at 3 months was 50%, and this was not significantly different between both groups (51.4 vs 50.0%, P = 0.90). Having <6 years of formal education [risk ratio (RR) = 3.014, 95% confidence interval (CI) = 1.054–8.618, P = 0.040] was significantly associated with POCD in the CCPB group, while the lowest hematocrit during cardiopulmonary bypass was independently associated with POCD in the MCPB group (RR = 0.931, 95% CI = 0.868–0.998, P = 0.044). The postoperative inflammatory markers and NSE levels were similar between the two groups.

Conclusions:

This study shows that the MCPB was not superior to CCPB with cell salvage and biocompatible tubing with regard to the neurocognitive outcomes measured by the RBANS.

Risk Factors of Intraoperative Dysglycemia in Elderly Surgical Patients

BACKGROUNDː Dysglycemia is associated with adverse outcome including increased morbidity and mortality in surgical patients. Acute insulin resistance due to the surgical stress response is seen as a major cause of so-called stress hyperglycemia. However, understanding of factors determining blood glucose (BG) during surgery is limited. Therefore, we investigated risk factors contributing to intraoperative dysglycemia. METHODSː In this subgroup investigation of the BIOCOG study, we analyzed 87 patients of ≥ 65 years with tight intraoperative BG measurement every 20 min during elective surgery. Dysglycemia was defined as at least one intraoperative BG measurement outside the recommended target range of 80-150 mg/dL. Additionally, all postoperative BG measurements in the ICU were obtained. Multivariable logistic regression analysis adjusted for age, sex, American Society of Anesthesiologists (ASA) status, diabetes, type and duration of surgery, minimum Hemoglobin (Hb) and mean intraoperative norepinephrine use was performed to identify risk factors of intraoperative dysglycemia. RESULTSː 46 (52.9%) out of 87 patients developed intraoperative dysglycemia. 31.8% of all intraoperative BG measurements were detected outside the target range. Diabetes [OR 9.263 (95% CI 2.492, 34.433); p=0.001] and duration of surgery [OR 1.005 (1.000, 1.010); p=0.036] were independently associated with the development of intraoperative dysglycemia. Patients who experienced intraoperative dysglycemia had significantly elevated postoperative mean (p<0.001) and maximum BG levels (p=0.001). Length of ICU (p=0.007) as well as hospital stay (p=0.012) were longer in patients with dysglycemia. CONCLUSIONSː Diabetes and duration of surgery were confirmed as independent risk factors for intraoperative dysglycemia, which was associated with adverse outcome. These patients, therefore, might require intensified glycemic control. Increased awareness and management of intraoperative dysglycemia is warranted.

Continuous glucose monitoring identifies relationship between optimized glycemic control and post-discharge acute care facility needs

Objective

Hyperglycemia is an independent risk factor in hospitalized patients for adverse outcomes, even if patients are not diabetic. We used continuous glucose monitoring to evaluate whether glycemic control (hyperglycemia) in the first 72 h after an intensive care admission was associated with the need for admission to a post discharge long-term medical facility.

Results

We enrolled 59 coronary artery bypass grafting patients. Poor glycemic control was defined as greater than 33% of continuous glucose monitoring values < 70 and > 180 mg/dL (group 1); and then these patients were reevaluated with a less strict definition of poor glycemic control with greater than 25% of continuous glucose values < 70 and > 180 mg/dL (group 2). In group 1 4/10 (40.0%) whose glucose was not well controlled went to an extended care post discharge facility as opposed to 6/49 (12.2%) that were well controlled. In reevaluation as group 2, 5/14 (35.7%) whose glucose was not well controlled went to an extended care post discharge facility as opposed to 5/45 (11.1%) who were well controlled. Admission to a post discharge facility was increased in patients with poor glycemic control p = 0.045 and p = 0.042 for group 1 and group 2, and with odds ratios of 4.8 (95% CI 1.0–22.5) and 4.4 (95% CI 1.0–19.4), respectively.