Postoperative cognitive dysfunction is rare after fast-track hip- and knee arthroplasty - But potentially related to opioid use

Vagus nerve stimulation (VNS) preventing postoperative cognitive dysfunction (POCD): two potential mechanisms in cognitive function

Postoperative cognitive dysfunction (POCD) impacts a significant number of patients annually, frequently impairing their cognitive abilities and resulting in unfavorable clinical outcomes. Aimed at addressing cognitive impairment, vagus nerve stimulation (VNS) is a therapeutic approach, which was used in many mental disordered diseases, through the modulation of vagus nerve activity. In POCD model, the enhancement of cognition function provided by VNS was shown, demonstrating VNS effect on cognition in POCD. In the present study, we primarily concentrates on elucidating the role of the VNS improving the cognitive function in POCD, via two potential mechanisms: the inflammatory microenvironment and epigenetics. This study provided a theoretical support for the feasibility that VNS can be a potential method to enhance cognition function in POCD.

Spinal Anesthesia Reduces Perioperative Polypharmacy and Opioid Burden in Patients Over 65 Who Undergo Transforaminal Lumbar Interbody Fusion

BACKGROUND

Polypharmacy and opioid administration are thought to increase the risk of postoperative cognitive dysfunction and delirium in elderly patients. Spinal anesthesia (SA) holds potential to reduce perioperative polypharmacy in spine surgery. As more geriatric patients undergo spine surgery, understanding how SA can reduce polypharmacy and opioid administration is warranted. We aim to compare the perioperative polypharmacy and dose of administered opioids in patients ≥65 years who undergo transforaminal lumbar interbody fusion (TLIF) under SA versus general anesthesia (GA).

METHODS

A retrospective analysis of 200 patients receiving a single-surgeon TLIF procedure at a single academic center (2014-2021) was performed. Patients underwent the procedure with SA (n = 120) or GA (n = 80). Demographic, procedural, and medication data were extracted from the medical record. Opioid consumption was quantified as morphine milligram equivalents (MME). Statistical analyses included χ2 or Student's t-test.

RESULTS

Patients receiving SA were administered 7.45 medications on average versus 12.7 for GA patients (P < 0.001). Average perioperative opioid consumption was 5.17 MME and 20.2 MME in SA and GA patients, respectively (P < 0.001). The number of patients receiving antiemetics and opioids remained comparable postoperatively, with a mean of 32.2 MME in the GA group versus 27.5 MME in the SA group (P = 0.14). Antiemetics were administered less often as a prophylactic in the SA group (32%) versus 86% in the GA group (P < 0.001).

CONCLUSIONS

SA reduces perioperative polypharmacy in patients ≥65 years undergoing TLIF procedures. Further research is necessary to determine if this reduction correlates to a decrease the incidence of postoperative cognitive dysfunction and delirium.

Association between anaesthesia-related factors and postoperative neurocognitive disorder: a post-hoc analysis

BACKGROUND

Postoperative neurocognitive disorder (pNCD) is common after surgery. Exposure to anaesthetic drugs has been implicated as a potential cause of pNCD. Although several studies have investigated risk factors for the development of cognitive impairment in the early postoperative phase, risk factors for pNCD at 3 months have been less well studied. The aim of this study was to identify potential anaesthesia-related risk factors for pNCD at 3 months after surgery.

METHODS

We analysed data obtained for a prospective observational study in patients aged ≥ 65 years who underwent surgery for excision of a solid tumour. Cognitive function was assessed preoperatively and at 3 months postoperatively using 5 neuropsychological tests. Postoperative NCD was defined as a postoperative decline of ≥ 25% relative to baseline in ≥ 2 tests. The association between anaesthesia-related factors (type of anaesthesia, duration of anaesthesia, agents used for induction and maintenance of anaesthesia and analgesia, the use of additional vasoactive medication, depth of anaesthesia [bispectral index] and mean arterial pressure) and pNCD was analysed using logistic regression analyses. Furthermore, the relation between anaesthesia-related factors and change in cognitive test scores expressed as a continuous variable was analysed using a z-score.

RESULTS

Of the 196 included patients, 23 (12%) fulfilled the criteria for pNCD at 3 months postoperatively. A low preoperative score on Mini-Mental State Examination (OR, 8.9 [95% CI, (2.8-27.9)], p < 0.001) and a longer duration of anaesthesia (OR, 1.003 [95% CI, (1.001-1.005)], p = 0.013) were identified as risk factors for pNCD. On average, patients scored higher on postoperative tests (mean z-score 2.35[± 3.13]).

CONCLUSION

In this cohort, duration of anaesthesia, which is probably an expression of the complexity of the surgery, was the only anaesthesia-related predictor of pNCD. On average, patients' scores on cognitive tests improved postoperatively.

Effects of qCON and qNOX-guided general anaesthesia management on patient opioid use and prognosis: a study protocol

INTRODUCTION

The adverse effects of general anaesthetic drugs (especially opioids) cannot be ignored. However, current nociceptive-monitoring techniques still lack consistency in guiding the use of opioids. This trial will study the demand for opioid use and patient prognosis in qCON and qNOX-guided general anaesthesia management.

METHODS AND ANALYSIS

This prospective, randomised, controlled trial will randomly recruit 124 patients undergoing general anaesthesia for non-cardiac surgery in equal numbers to either the qCON or BIS group. The qCON group will adjust intraoperative propofol and remifentanil dosage according to qCON and qNOX values, while the BIS group will adjust according to BIS values and haemodynamic fluctuations. The differences between the two groups will be observed in remifentanil dosing and prognosis. The primary outcome will be intraoperative remifentanil use. Secondary outcomes will include propofol consumption; the predictive ability of BIS, qCON and qNOX on conscious responses, noxious stimulus and body movements; and changes in cognitive function at 90 days postoperatively.

ETHICS AND DISSEMINATION

This study involves human participants and was approved by the Ethics Committee of the Tianjin Medical University General Hospital (IRB2022-YX-075-01). Participants gave informed consent to participate in the study before taking part. The study results will be published in peer-reviewed journals and presented at relevant academic conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2200059877.

Acute pain management and long term outcomes

PURPOSE OF REVIEW

The acute inflammatory reaction induced by tissue trauma causes pain but also promotes recovery. Recovery is highly variable among peoples. Effective acute pain (AP) management is very important but remains suboptimal what could affect long term outcomes. The review questions the impact of either failure or effectiveness of AP treatments and the choice of analgesic drugs on different long-term outcomes after tissue trauma.

RECENT FINDINGS

Pain control during mobilization is mandatory to reduce the risk of complications which exacerbate and prolong the inflammatory response to trauma, impairing physical recovery. Common analgesic treatments show considerable variability in effectiveness among peoples what argues for an urgent need to develop personalized AP management, that is, finding better responders to common analgesics and targeting challenging patients for more invasive procedures. Optimal multimodal analgesia to spare opioids administration remains a priority as opioids may enhance neuroinflammation, which underlies pain persistence and precipitates neurocognitive decline in frail patients. Finally, recent findings demonstrate that AP treatments which modulate nociceptive and inflammatory pain should be used with caution as drugs which inhibit inflammation like nonsteroidal antiinflammatory drugs and corticoids might interfere with natural recovery processes.

SUMMARY

Effective and safe AP management is of far greater importance than previously realized. Evidence of suboptimal AP management in many patients and recent reports pointing out the impact of current treatments on long term outcomes argue for further research in the field.

Microstate analyses as an indicator of anesthesia-induced unconsciousness

OBJECTIVE

The objective of this study was to identify differences in electroencephalographic microstate topographies across three perioperative phases: anesthetic pre-induction, surgical anesthesia, and post-anesthesia care unit (PACU) admission.

METHODS

Whole-scalp 16-channel electroencephalographic recordings were taken throughout the perioperative period on n = 22 adult, non-cardiac surgical patients.

RESULTS

Several differences between perioperative periods were identified. Most notably, during surgical anesthesia, patients demonstrated increased mean duration and, consequently, a reduction in the occurrence of microstates when compared to both preoperative baseline and PACU admission. We also observed the presence of microstate F with propofol anesthesia during surgery, which had been previously identified with propofol infusion in laboratory settings using human volunteers. Finally, we observed inverse age effects with mean occurrence and duration of microstates, particularly during PACU recovery.

CONCLUSIONS

Microstate duration is significantly increased during surgery compared to both pre-induction and PACU recovery. These data suggest that microstate topographies may be useful in monitoring anesthetic depth.

SIGNIFICANCE

This work highlights the potential for microstate analysis in the perioperative setting. We identified distinct topographical signatures across perioperative periods and with increasing age, which is predictive of post-operative delirium.

Effect of acute pain on the association between preoperative cognitive impairment and postoperative delirium: a secondary analysis of three trials

BACKGROUND

The association between preoperative cognitive impairment, postoperative pain, and postoperative delirium in older patients after noncardiac surgery is not known.

METHODS

This was a secondary analysis of datasets from three previous studies. Patients aged ≥55 yr who underwent elective noncardiac surgery were enrolled. Preoperative cognitive impairment was defined as Mini-Mental State Examination <27. Pain intensity with movement was assessed using an 11-point numeric rating scale at 12-h intervals during the first 72 h after surgery; time-weighted average (TWA) pain score was calculated. Primary outcome was the occurrence of delirium within the first 5 postoperative days. Mediation analysis was used to investigate the relationships between cognitive impairment, pain score, and delirium.

RESULTS

A total of 1497 patients were included. Prevalence of preoperative cognitive impairment was 40.3% (603/1497). Patients with cognitive impairment suffered higher TWA pain score within 72 h (4 [3-5] vs 3 [2-5], P=0.004) and more delirium within 5 days (12.9% [78/603] vs 4.9% [44/894], P<0.001) when compared with those without. Total and direct associations between cognitive impairment and delirium were (adjusted β) 8.3% (95% confidence interval [CI], 4.8-12.0%; P<0.001) and 7.8% (95% CI, 4.4-12.0%; P<0.001), respectively. A significant indirect association with acute pain was observed between cognitive impairment and delirium (adjusted β=0.4%; 95% CI, 0.1-1.0%; P=0.006), accounting for 4.9% of the total effect.

CONCLUSIONS

The association between preoperative cognitive impairment and delirium is significantly mediated by acute pain in patients after noncardiac surgery. Considering the small effect size, clinical significance of this mediation effect requires further investigation.

Perioperative risk factors associated with increased incidence of postoperative delirium: systematic review, meta-analysis, and Grading of Recommendations Assessment, Development, and Evaluation system report of clinical literature

BACKGROUND

Systematic reviews to date have neglected to exclusively include studies using a validated diagnostic scale for postoperative delirium and monitoring patients for more than 24 h. Evidence on current risk factors is evolving with significantly heterogeneous study designs, inconsistent reporting of results, and a lack of adjustment for bias.

METHODS

This systematic review and meta-analysis aimed to identify risk factors for postoperative delirium in an adult patient population. Study designs suitable for this review included full-text articles, RCTs, observational studies, cohort studies, and case-control studies. Extracted variables from the 169 (7.4%) selected studies were included in qualitative synthesis, quantitative synthesis, and a postoperative delirium checklist. The 16 variables included in the checklist were selected based on consistency, direction of effect, number of studies, and clinical utility as a reference for future studies.

RESULTS

A total of 576 variables were extracted, but only six were eligible for meta-analysis. Age (mean difference [MD]=4.94; 95% confidence interval [CI], 2.93-6.94; P<0.001), American Society of Anesthesiologists physical status >2 (odds ratio [OR]=2.27; 95% CI, 1.47-3.52; P<0.001), Charlson Comorbidity Index ≥2 (OR=1.9; 95% CI, 1.11-3.25; P=0.0202), and Mini-Mental State Examination (MD=-1.94; 95% CI, -3.6 to -0.27; P=0.0224) were statistically significant.

CONCLUSIONS

Risk factors can assist in clinical decision-making and identification of high-risk patients. Literature analysis identified inconsistent methodology, leading to challenges in interpretation. A standardised format and evidence-based approach should guide future studies.

Research progress on perioperative blood-brain barrier damage and its potential mechanism

The blood-brain barrier (BBB) is an important barrier separating the central nervous system from the periphery. The composition includes endothelial cells, pericytes, astrocytes, synapses and tight junction proteins. During the perioperative period, anesthesia and surgical operations are also a kind of stress to the body, which may be accompanied by blood-brain barrier damage and brain metabolism dysfunction. Perioperative blood-brain barrier destruction is closely associated with cognitive impairment and may increase the risk of postoperative mortality, which is not conducive to enhanced recovery after surgery. However, the potential pathophysiological process and specific mechanism of blood-brain barrier damage during the perioperative period have not been fully elucidated. Changes in blood-brain barrier permeability, inflammation and neuroinflammation, oxidative stress, ferroptosis, and intestinal dysbiosis may be involved in blood-brain barrier damage. We aim to review the research progress of perioperative blood-brain barrier damage and its potential adverse effects and potential molecular mechanisms, and provide ideas for the study of homeostasis maintenance of brain function and precision anesthesia.

Tau protein plays a role in the mechanism of cognitive disorders induced by anesthetic drugs

Cognitive disorders are mental health disorders that can affect cognitive ability. Surgery and anesthesia have been proposed to increase the incidence of cognitive dysfunction, including declines in memory, learning, attention and executive function. Tau protein is a microtubule-associated protein located in the axons of neurons and is important for microtubule assembly and stability; its biological function is mainly regulated by phosphorylation. Phosphorylated tau protein has been associated with cognitive dysfunction mediated by disrupting the stability of the microtubule structure. There is an increasing consensus that anesthetic drugs can cause cognitive impairment. Herein, we reviewed the latest literature and compared the relationship between tau protein and cognitive impairment caused by different anesthetics. Our results substantiated that tau protein phosphorylation is essential in cognitive dysfunction caused by anesthetic drugs, and the possible mechanism can be summarized as "anesthetic drugs-kinase/phosphatase-p-Tau-cognitive impairment".

Identification of individuals at risk for postoperative cognitive dysfunction (POCD)

Postoperative cognitive dysfunction (POCD) is common, occurring in around 10-54% of individuals within first few weeks after surgery. Although the majority of POCD is less commonly persistent later than 3 months following surgery, the condition increases length of stay (LOS), mortality and long-term cognitive decline, raising the need for a broad screening to identify individuals at risk for POCD during the perioperative period. In this narrative review, we summarize preoperative, intraoperative and postoperative risk factors for POCD reported in last 5 years and discuss neuropsychological tools and potential biomarkers and time points for assessment that might be suitable for clinical use. We aim to provide crucial information for developing a strategy of routine screening for POCD, which may assist with better identification of at-risk individuals for early interventions. Very importantly, the utilization of a standardized strategy may also allow higher consistency and comparability across different studies.

The effect of opioid-sparing anesthesia regimen on short-term cognitive function after thoracoscopic surgery: a prospective cohort study

Background

As type of surgery and opioids are suggested risk factors for the development of cognitive decline after surgery, we evaluated the effect of an opioid-sparing anesthesia regimen involving preoperative erector spinae block and continuous infusion of flurbiprofen on the incidence of cognitive decline after video-assisted thoracoscopic surgery.

Methods

In this observational study, patients over 18 years old presenting for elective video-assisted thoracoscopic surgery were divided into two groups, the erector spinae plane block group (ESPB group, who received preoperative single shot of bi-level ESPB at T4 and T6 levels) and the control group who received intercostal nerve blocks through T5 to T7 intercostal spaces along mid-axillary line after surgery. Continuous infusion of flurbiprofen (8 mg/h) and intravenous oxycodone rescue (1 mg/bolus, lockout time 10 minutes) were provided as postoperative analgesics. Cognitive function was measured one day before and 48 h after surgery with brief Cogstate computerized battery (CCB).

Results

There were 60 patients included with 30 in each group. Perioperative sufentanil dose was significantly reduced in ESPB group. Nine (30%) and 15 (50%) patients had delayed neurocognitive recovery in the ESPB group and the control group respectively. Psychomotor speed and visual attention tests were the two tests that patients showed cognitive decline. The results of multivariate regression revealed that patients who were more than 53.5 years of age (OR 9.213, 95% CI 1.789, 47.437, P = 0.008) and low levels of education (less than 9 years of complimentary education) (OR 6.829, 95% CI 1.068, 43.677, P = 0.042) were independent risk factors for postoperative delayed neurocognitive recovery. For subgroup analysis, ESPB could reduce the occurrence of delayed neurocognitive recovery in patients with both risk factors (6/10 (60%) vs. 11/11 (100%), P = 0.004) compared to the control group.

Conclusions

Middle-aged people and low levels of education are independent risk factors for delayed neurocognitive recovery after thoracoscopic surgery. ESPB has the potential to prevent cognitive decline in high-risk patients.

Trial registration

ChiCTR1800014508 (www.chictr.org.cn, January 17, 2018; Hong Zhao, M.D.). URL: http://www.chictr.org.cn/showproj.aspx?proj=24778. The date of the enrolment of the first participant to the trial was January 22, 2018.

Mitigation of perioperative neurocognitive disorders: A holistic approach

William Morton introduced the world to ether anesthesia for use during surgery in the Bullfinch Building of the Massachusetts General Hospital on October 16, 1846. For nearly two centuries, the prevailing wisdom had been that the effects of general anesthetics were rapidly and fully reversible, with no apparent long-term adverse sequelae. Despite occasional concerns of a possible association between surgery and anesthesia with dementia since 1887 (Savage, 1887), our initial belief was robustly punctured following the publication in 1998 of the International Study of Post-Operative Cognitive Dysfunction [ISPOCD 1] study by Moller et al. (1998) in The Lancet, in which they demonstrated in a prospective fashion that there were in fact persistent adverse effects on neurocognitive function up to 3 months following surgery and that these effects were common. Since the publication of that landmark study, significant strides have been made in redefining the terminology describing cognitive dysfunction, identifying those patients most at risk, and establishing the underlying etiology of the condition, particularly with respect to the relative contributions of anesthesia and surgery. In 2018, the International Nomenclature Consensus Working Group proposed new nomenclature to standardize identification of and classify perioperative cognitive changes under the umbrella of perioperative neurocognitive disorders (PND) (Evered et al., 2018a). Since then, the new nomenclature has tried to describe post-surgical cognitive derangements within a unifying framework and has brought to light the need to standardize methodology in clinical studies and motivate such studies with hypotheses of PND pathogenesis. In this narrative review, we highlight the relevant literature regarding recent key developments in PND identification and management throughout the perioperative period. We provide an overview of the new nomenclature and its implications for interpreting risk factors identified by clinical association studies. We then describe current hypotheses for PND development, using data from clinical association studies and neurophysiologic data where appropriate. Finally, we offer broad clinical guidelines for mitigating PND in the perioperative period, highlighting the role of Brain Enhanced Recovery After Surgery (Brain-ERAS) protocols.

Key Components, Current Practice and Clinical Outcomes of ERAS Programs in Patients Undergoing Orthopedic Surgery: A Systematic Review

Enhanced recovery after surgery (ERAS) protocols have led to improvements in outcomes in several surgical fields, through multimodal optimization of patient pathways, reductions in complications, improved patient experiences and reductions in the length of stay. However, their use has not been uniformly recognized in all orthopedic fields, and there is still no consensus on the best implementation process. Here, we evaluated pre-, peri-, and post-operative key elements and clinical evidence of ERAS protocols, measurements, and associated outcomes in patients undergoing different orthopedic surgical procedures. A systematic literature search on PubMed, Scopus, and Web of Science Core Collection databases was conducted to identify clinical studies, from 2012 to 2022. Out of the 1154 studies retrieved, 174 (25 on spine surgery, 4 on thorax surgery, 2 on elbow surgery and 143 on hip and/or knee surgery) were considered eligible for this review. Results showed that ERAS protocols improve the recovery from orthopedic surgery, decreasing the length of hospital stays (LOS) and the readmission rates. Comparative studies between ERAS and non-ERAS protocols also showed improvement in patient pain scores, satisfaction, and range of motion. Although ERAS protocols in orthopedic surgery are safe and effective, future studies focusing on specific ERAS elements, in particular for elbow, thorax and spine, are mandatory to optimize the protocols.

Perioperative neurocognitive disorders: A narrative review focusing on diagnosis, prevention, and treatment

Perioperative neurocognitive disorders (NCDs) refer to neurocognitive abnormalities detected during the perioperative periods, including preexisting cognitive impairment, preoperative delirium, delirium occurring up to 7 days after surgery, delayed neurocognitive recovery, and postoperative NCD. The Diagnostic and Statistical Manual of Mental Disorders‐5th edition (DSM‐5) is the golden standard for diagnosing perioperative NCDs. Given the impracticality of using the DSM‐5 by non‐psychiatric practitioners, many diagnostic tools have been developed and validated for different clinical scenarios. The etiology of perioperative NCDs is multifactorial and includes predisposing and precipitating factors. Identifying these risk factors is conducive to preoperative risk stratification and perioperative risk reduction. Prevention for perioperative NCDs should include avoiding possible contributors and implementing nonpharmacologic and pharmacological interventions. The former generally includes avoiding benzodiazepines, anticholinergics, prolonged liquid fasting, deep anesthesia, cerebral oxygen desaturation, and intraoperative hypothermia. Nonpharmacologic measures include preoperative cognitive prehabilitation, comprehensive geriatric assessment, implementing fast‐track surgery, combined use of regional block, and sleep promotion. Pharmacological measures including dexmedetomidine, nonsteroidal anti‐inflammatory drugs, and acetaminophen are found to have beneficial effects. Nonpharmacological treatments are the first‐line measures for established perioperative NCDs. Pharmacological treatments are still limited to severely agitated or distressed patients.

High-dose preoperative glucocorticoid for prevention of emergence and postoperative delirium in liver resection: A double-blinded randomized clinical trial substudy

BACKGROUND

Emergence delirium (ED) and postoperative delirium (POD) are associated with increased morbidity and mortality and occur in up to one-third of patients undergoing major non-cardiac surgery, where the underlying pathogenesis is multifactorial, including increased inflammation. We aimed to assess the effect of pre-operative high- versus low-dose glucocorticoid on the occurrence of ED and POD.

METHODS

This was a substudy from a randomized, double-blinded clinical trial. Patients ≥18 years, undergoing open liver resection were randomized 1:1 to high-dose (HD, 10 mg/kg methylprednisolone) or low-dose (LD, 8 mg dexamethasone) glucocorticoid and assessed for ED and POD for a maximum of 4 days during hospitalization. The 3-min Diagnostic Interview for CAM-defined delirium (3D-CAM) was used for assessment, 15 and 90 min after arrival in the post-anesthesia care unit (PACU), and subsequently once daily in the ward.

RESULTS

Fifty-three patients were included in this secondary substudy (26 HD-group and 27 LD-group). ED occurred in n = 5 HD versus n = 6 LD patients 15 min after PACU arrival. At 90 min after PACU arrival, 4 patients had ED, all from LD-group, and resulted in significantly longer PACU admission, 273 versus 178 min in ED versus Non-ED patients. During the first 4 days in the ward, n = 5 patients had at least one occurrence of POD, all from LD-group.

CONCLUSIONS

The primary finding of the current substudy was a lower occurrence of ED/POD in the PACU 90 min after arrival and during the first four postoperative days in patients receiving high-dose glucocorticoid compared with patients receiving low-dose glucocorticoid. The two study groups were not evenly balanced concerning known explanatory factors, i.e., age and size of surgery, which calls for larger studies to elucidate the matter.

Nonopioid Analgesics for the Perioperative Geriatric Patient: A Narrative Review

Management of acute perioperative pain in the geriatric patient can be challenging as the physiologic and pharmacokinetic changes associated with aging may predispose older patients to opioid-related side effects. Furthermore, elderly adults are more susceptible to postoperative delirium and postoperative cognitive dysfunction, which may be exacerbated by both poorly controlled postoperative pain and commonly used pain medications. This narrative review summarizes the literature published in the past 10 years for several nonopioid analgesics commonly prescribed to the geriatric patient in the perioperative period. Nonopioid analgesics are broken down as follows: medications prescribed throughout the perioperative period (acetaminophen and nonsteroidal anti-inflammatory drugs), medications limited to the acute perioperative setting (N-methyl-D-aspartate receptor antagonists, dexmedetomidine, dexamethasone, and local anesthetics), and medications to be used with caution in the geriatric patient population (gabapentinoids and muscle relaxants). Our search identified 1757 citations, but only 33 specifically focused on geriatric analgesia. Of these, only 21 were randomized clinical trials' and 1 was a systematic review. While guidance in tailoring pain regimens that focus on the use of nonopioid medications in the geriatric patient is lacking, we summarize the current literature and highlight that some nonopioid medications may extend benefits to the geriatric patient beyond analgesia.

Comparison of the Effects of Epidural Anesthesia and General Anesthesia on Perioperative Cognitive Function and Deep Vein Thrombosis in Patients Undergoing Total Knee Arthroplasty

Objective

To explore the effects of epidural anesthesia and general anesthesia on perioperative cognitive function and deep vein thrombosis (DVT) in patients undergoing total knee arthroplasty (TKA).

Methods

Total of 68 patients undergoing TKA in our hospital from September 2019 to March 2021 were selected and divided into the control group under general anesthesia and the observation group under epidural anesthesia according to the different anesthesia methods, 34 patients in each group. TKA was selected in both groups and performed by the same group of physicians, anesthesiologists, and nursing staff. The mean arterial pressure (MAP), heart rate (HR), and blood oxygen saturation (SpO₂) were observed immediately before anesthesia (T1), 30 min after anesthesia (T2), after surgery (T3), and 1 d after surgery (T4). The changes of platelet (PLC), fibrinogen (Fbg), prothrombin time (PT), activated partial thrombin time (APTT), and other coagulation indicators were recorded. The Montreal Cognitive Assessment (MoCA) scores before surgery and 1 d and 3 d after surgery were observed. The blood samples of the two groups were collected before surgery and 1 d and 3 d after surgery, and the levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the peripheral blood of the two groups were measured by ELISA. The number of postoperative mental disorders and DVT in the two groups was calculated.

Results

The MAP and HR of T4 were lower than those of T1, T2, and T3. The MAP of T2, T3, and T4 in the observation group was lower than that in the control group (P < 0.05), and the SpO₂ of T1–T4 in the two groups did not change significantly, and there was no significant difference between the two groups (P > 0.05). Compared with T1, there was no significant difference in PLC, Fbg, and PT in the observation group T4 (P > 0.05), and APTT was lower than T1 (P < 0.05). The PLC, PT, and APTT of T4 in the control group were all lower than those of T1 (P < 0.05), and there was no significant difference between Fbg and T1 (P > 0.05). The PLC, Fbg, and PT of T4 in the observation group were higher than those in the control group, while APTT was lower than that in the control group (P < 0.05). The MoCA scores of patients in both groups on the 1st and 3rd day after operation were lower than those before operation, and the observation group was higher than that in the control group (P < 0.05). The BDNF and NGF of patients in both groups were lower than those before operation on the 1st day after operation, and the BDNF and NGF in the observation group were higher than those in the control group on the 1st and 3rd day after operation (P < 0.05). The mental disorder (2.94%) and DVT incidence (2.94%) in the observation group were lower than those in the control group (29.41%, 26.47%) (P < 0.05).

Conclusion

Epidural anesthesia for patients with TKA can obtain better clinical effects, maintain stable hemodynamic and coagulation states, reduce stress response of patients at the same time, and reduce perioperative cognitive dysfunction and the incidence of DVT in patients.

[Effects of different postoperative analgesic strategies on postoperative neurocognitive function and quality of recovery in elderly patients undergoing one lung ventilation]

OBJECTIVE

To evaluate the effects of different postoperative analgesic strategies on neurocognitive function and quality of recovery in elderly patients at 7 days after thoracic surgery with one lung ventilation.

METHODS

Ninety elderly patients undergoing video-assisted thoracic surgery were randomized into 3 groups (n=30) to receive postoperative analgesia with thoracic paravertebral block analgesia (TA), epidural analgesia (EA) and intravenous analgesia (GA). Before and at 7 days after the surgery, the patients' cognitive function was assessed using Mini-Mental State Examination (MMSE), and their early recovery at 7 days postoperatively was evaluated using Quality of Recovery-40 items (QoR-40).

RESULTS

The patients in TA and EA groups had significantly higher MMSE scores and lower incidence of postoperative neurocognitive dysfunction (PNCD) than those in GA group without significant difference between the former two groups. At 7 days after the surgery, serum levels of S100-β and MMP-9 were significantly higher in GA group than in TA and EA group, and did not differ significantly between the latter two groups. QoR-40 scores were significantly higher in TA and EA groups than in GA group, and were higher in TA group than in EA group. The chest intubation time and length of hospital stay were significantly shorter in TA and EA groups than in GA group.

CONCLUSIONS

In elderly patients undergoing surgeries with one lung ventilation, general anesthesia combined with either postoperative continuous thoracic paravertebral block or epidural analgesia can significantly improve postoperative neurocognitive function and quality of recovery, but continuous thoracic paravertebral block analgesia can be more advantageous for improving postoperative quality of recovery.

Chronic post-operative opioid use after open cardiac surgery: A Danish population-based cohort study

BACKGROUND

Knowledge of chronic opioid use after cardiac surgery is sparse. We therefore aimed to describe the proportion of new chronic post-operative opioid use after open cardiac surgery.

METHODS

We used prospectively registered data from a national prescription registry and a clinical registry of 29 815 first-time cardiac surgeries from three Danish university hospitals. Data collection spanned from 2003 to 2016. The main outcome was chronic post-operative opioid use, defined as at least one opioid dispensing in the fourth post-operative quarter. Data were assessed for patient-level predictors of chronic post-operative opioid use, including pre-operative opioid use, opioid use at discharge, comorbidities, and procedural related variables.

RESULTS

The overall proportion of post-operative opioid use was 10.6% (95% CI: 10.2-10.9). The proportion of new chronic post-operative opioid use was 5.7% (95% CI: 5.5-6.0) among pre-operative opioid naïve patients. The corresponding proportions among patients, who pre-operatively used low or high dose opioid (1-500 mg or > 500 mg cumulative morphine equivalent opioid), were 68.3% (95% CI: 66.1-70.4) and 76.3% (95% CI: 74.0-78.5) respectively. Risk factors associated with new chronic post-operative opioid use included: female gender, underweight and obesity, pre-operative comorbidities, acute surgery, ICU-time > 1 day, and post-operative complications. Strongest predictor of chronic post-operative opioid use was post-discharge use of opioid within one month after surgery (odds ratio 3.3, 95% CI: 2.8-4.0).

CONCLUSION

New chronic post-operative opioid use after open cardiac surgery is common. Focus on post-discharge opioid use may help clinicians to reduce rates of new chronic opioid users.

Hypoxemia following hospital discharge after fast-track hip and knee arthroplasty - A prospective observational study subanalysis

BACKGROUND

Post-operative hypoxemia is prevalent in hospitalized patients and may adversely affect recovery. However, little data exist on the post-discharge phase or details on duration, severity and potential risk factors. Thus, we investigated the incidence and risk factors for severe desaturation during the first post-operative week after THA/TKA by continuous nocturnal oxygen saturation monitoring.

METHODS

The study was a secondary analysis of a prospective cohort study of 112 patients undergoing fast-track THA/TKA. Patients with known sleep apnoea were excluded. Oxygen saturation and heart rate were recorded by a wireless wrist-worn pulse oximeter 2 nights before and 7 nights after surgery. Data on demographics, opioid consumption and cognitive function were collected from medical charts, patient diaries and clinical testing respectively. The primary outcome was occurrence of severe desaturation defined as periods with saturation <85% lasting ≥10 minutes. Secondary outcomes included description of various saturation levels and relevant risk factors.

RESULTS

Severe oxygen desaturation occurred in 35% of the patients during the first post-operative week. Duration and severity of hypoxemic episodes increased after the first post-operative day. Pre-operative episodes of hypoxemia significantly increased the risk of post-operative hypoxemic events (OR 2.4-4.4, CI 0.4-46), while pre- and post-operative opioid use, age, gender, ASA classification, type of surgery or anaesthesia were significantly related to the development of post-operative hypoxemia.

CONCLUSIONS

One third of the patients suffered from increased and prolonged episodes of severe nocturnal hypoxemia during the first week after THA/TKA discharge. Increased risk for severe hypoxemic episodes was related to pre-operative hypoxemia.

Management of Ambulatory Anesthesia in Older Adults

The number of older patients is increasing globally. Combined with the growing number of ambulatory surgeries, many older patients will undergo ambulatory surgery in the future. The ambulatory setting offers many advantages: early mobilization, higher patient satisfaction, lower costs, and a low incidence of several complications such as infections and thromboembolic events. Moreover, cognitive recovery seems to be enhanced compared with in-hospital surgery, and both frail patients and patients with dementia can benefit from ambulatory surgery. This review provides suggestions for managing perioperative anesthesia for older patients in the ambulatory setting. Not all older patients are eligible for ambulatory surgery, and clinicians must be aware of risk factors for complications, especially frailty. Most anesthesia techniques and agents can be used in the ambulatory setting, but short-acting agents are preferred to ensure fast recovery. Both regional and general anesthesia are useful, but clinicians must be familiar with the physiological changes and specific implications in the older population. The older patients are more sensitive to anesthetic agents, meaning that a lower dose is needed to obtain the desired effect. However, they exhibit huge variation in pharmacodynamics and pharmacokinetics. Prolonged onset time may lead to overdosing and extended recovery. After surgery, effective pain management with opioid minimization is essential to ensure rapid recovery.

Postoperative neurocognitive disorders

A decline in cognitive function is a frequent complication of major surgery. Postoperative cognitive impairments have generally been divided into short- (postoperative delirium) and long-term disturbances (postoperative cognitive dysfunction [POCD]). Long-term impairments are often subtle and overlooked. They need to be objectively assessed using neuropsychological tests to be diagnosed. Although POCD has been the subject of considerable research over the past decades, it remains uncertain why some patients do not return to preoperative levels of cognitive function. Surgery and anesthesia have both been implicated to play a role in POCD development, and certain patient-related factors, such as advanced age and low preoperative baseline cognitive function, have consistently been found to predict postoperative cognitive decline. This article will present an overview of POCD and its etiology and provide advice on possible strategies on its prevention.

The Effect of Intraoperative Methadone Compared to Morphine on Postsurgical Pain: A Meta-Analysis of Randomized Controlled Trials

Methods

We performed a quantitative systematic review of randomized controlled trials in PubMed, Embase, Cochrane Library, and Google Scholar electronic databases. Meta-analysis was performed using the random effects model, weighted mean differences (WMD), standard deviation, 95% confidence intervals, and sample size. Methodological quality was evaluated using Cochrane Collaboration's tool.

Results

Seven randomized controlled trials evaluating 337 patients across different surgical procedures were included. The aggregated effect of intraoperative methadone on postoperative opioid consumption did not reveal a significant effect, WMD (95% CI) of −0.51 (−1.79 to 0.76), (P=0.43) IV morphine equivalents. In contrast, the effect of methadone on postoperative pain demonstrated a significant effect in the postanesthesia care unit, WMD (95% CI) of −1.11 (−1.88 to −0.33), P=0.005, and at 24 hours, WMD (95% CI) of −1.35 (−2.03 to −0.67), P < 0.001.

Conclusions

The use of intraoperative methadone reduces postoperative pain when compared to morphine. In addition, the beneficial effect of methadone on postoperative pain is not attributable to an increase in postsurgical opioid consumption. Our results suggest that intraoperative methadone may be a viable strategy to reduce acute pain in surgical patients.