Non-neurological Surgery Research Articles

Adverse outcomes after surgery after a cerebrovascular accident or acute coronary syndrome: a retrospective observational cohort study

BackgroundDelaying surgery after a major cardiovascular event might reduce adverse postoperative outcomes. The time interval represents a potentially modifiable risk factor but is not well studied. MethodsThis was a longitudinal retrospective population-based cohort study, linking data from Hospital Episode Statistics for NHS England and the Myocardial Ischaemia National Audit Project. Adults undergoing noncardiac, non-neurologic surgery in 2007–2018 were included. The time interval between a preoperative cardiovascular event and surgery was the main exposure. The outcomes of interest were acute coronary syndrome (ACS), acute myocardial infarction (AMI), cerebrovascular accident (CVA) within 1 year of surgery, unplanned readmission (at 30 days and 1 year), and prolonged length of stay. Multivariable logistic regression models with restricted cubic splines were used to estimate adjusted odds ratios (aORs; age, sex, socioeconomic deprivation, and comorbidities). ResultsIn total, 877 430 people had a previous cardiovascular event and 20 582 717 were without an event. CVA, ACS, and AMI in the year after elective surgery were more frequent after prior cardiovascular events (adjusted hazard ratio 2.12, 95% confidence interval [CI] 2.08–2.16). Prolonged hospital stay (aOR 1.36, 95% CI 1.35–1.38) and 30-day (aOR 1.28, 95% CI 1.25–1.30) and 1-yr (aOR 1.60, 95% CI 1.58–1.62) unplanned readmission were more common after major operations in those with a prior cardiovascular event. After adjusting for the time interval between preoperative events until surgery, elective operations within 37 months were associated with an increased risk of postoperative ACS or AMI. The risk of postoperative stroke plateaued after a 20-month interval until surgery, irrespective of surgical urgency. ConclusionsThese observational data suggest increased adverse outcomes after a recent cardiovascular event can occur for up to 37 months after a major cardiovascular event.

Neuraxial anesthesia for non-neurological emergency surgery in a patient with acute ischemic stroke: a case report

BackgroundThe recent guidelines recommend delaying elective non-neurological surgery after an index stroke, but there is a lack of consensus regarding emergency surgery in patients with a recent stroke. Impaired cerebral autoregulation and altered baroreceptor function elevate the risk of recurrent stroke in this group. Moreover, the impact of anesthesia type (general vs. regional) for non-cardiovascular, non-neurological surgery in patients with an index stroke remains inconclusive.Case presentationA 67-year-old male with an acute mild ischemic stroke underwent emergency surgery for an obstructed right-sided direct inguinal hernia under combined spinal-epidural anesthesia. Pre-operative assessment showed stable hemodynamics, and perioperative measures were taken to ensure stable blood pressure. Neuraxial anesthesia was employed successfully, and the patient remained hemodynamically stable throughout the surgery and postoperative period. No neurological deficits were observed post-surgery, and follow-up up to 3 months revealed no cognitive impairment or neurological decline.ConclusionsNeuraxial anesthesia can be considered for patients with acute mild strokes requiring urgent non-neurological surgery, provided they are hemodynamically stable and without coagulopathy. However, the choice of anesthesia should be individualized based on factors such as neurological status, stroke severity, coagulation, and existing disabilities. This case highlights the importance of a personalized approach to anesthesia in emergency surgery for stroke patients.

Effectiveness and safety of enhanced postoperative care units for non-cardiac, non-neurological surgery: a systematic review protocol.

The proposed systematic review will evaluate the evidence on the effectiveness and safety of enhanced post-operative care (EPC) units on patient and health service outcomes in adult patients following non-cardiac, non-neurological surgery. The increase in surgical procedures globally has placed a significant economic and societal burden on health care systems. Recognizing this challenge, EPC units have emerged as a model of care, bridging the gap between traditional, ward-level care and intensive care. EPC offers benefits such as higher staff-to-patient ratios, close patient monitoring (eg, invasive monitoring), and access to critical interventions (eg, vasopressor support). However, there is a lack of well-established guidelines and empirical evidence regarding the safety and effectiveness of EPC units for adult patients following surgery. This review will include studies involving adult patients (≥18 years) undergoing any elective or emergency non-cardiac, non-neurological surgery, who have been admitted to an EPC unit. Experimental, quasi-experimental, and observational study designs will be eligible. This review will follow the JBI methodology for systematic reviews of effectiveness. The search strategy will identify published and unpublished studies from the Cochrane Library, MEDLINE (Ovid), Embase (Ovid), and Scopus, as well as gray literature sources, from 2010 to the present. Two independent reviewers will screen studies, extract data, and critically appraise selected studies using standardized JBI assessment tools. Where feasible, a statistical meta-analysis will be performed to combine study findings. The certainty of evidence will be assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. PROSPERO CRD42023455269.

Cognitive and Cerebrospinal Fluid Alzheimer's Disease-related Biomarker Trajectories in Older Surgical Patients and Matched Nonsurgical Controls.

Anesthesia and/or surgery accelerate Alzheimer's disease pathology and cause memory deficits in animal models, yet there is a lack of prospective data comparing cerebrospinal fluid (CSF) Alzheimer's disease-related biomarker and cognitive trajectories in older adults who underwent surgery versus those who have not. Thus, the objective here was to better understand whether anesthesia and/or surgery contribute to cognitive decline or an acceleration of Alzheimer's disease-related pathology in older adults. The authors enrolled 140 patients 60 yr or older undergoing major nonneurologic surgery and 51 nonsurgical controls via strata-based matching on age, sex, and years of education. CSF amyloid β (Aβ) 42, tau, and p-tau-181p levels and cognitive function were measured before and after surgery, and at the same time intervals in controls. The groups were well matched on 25 of 31 baseline characteristics. There was no effect of group or interaction of group by time for baseline to 24-hr or 6-week postoperative changes in CSF Aβ, tau, or p-tau levels, or tau/Aβ or p-tau/Aβ ratios (Bonferroni P > 0.05 for all) and no difference between groups in these CSF markers at 1 yr (P > 0.05 for all). Nonsurgical controls did not differ from surgical patients in baseline cognition (mean difference, 0.19 [95% CI, -0.06 to 0.43]; P = 0.132), yet had greater cognitive decline than the surgical patients 1 yr later (β, -0.31 [95% CI, -0.45 to -0.17]; P < 0.001) even when controlling for baseline differences between groups. However, there was no difference between nonsurgical and surgical groups in 1-yr postoperative cognitive change in models that used imputation or inverse probability weighting for cognitive data to account for loss to follow up. During a 1-yr time period, as compared to matched nonsurgical controls, the study found no evidence that older patients who underwent anesthesia and noncardiac, nonneurologic surgery had accelerated CSF Alzheimer's disease-related biomarker (tau, p-tau, and Aβ) changes or greater cognitive decline.

Perioperative stroke.

Ischaemic or haemorrhagic perioperative stroke (that is, stroke occurring during or within 30 days following surgery) can be a devastating complication following surgery. Incidence is reported in the 0.1-0.7% range in adults undergoing non-cardiac and non-neurological surgery, in the 1-5% range in patients undergoing cardiac surgery and in the 1-10% range following neurological surgery. However, higher rates have been reported when patients are actively assessed and in high-risk populations. Prognosis is significantly worse than stroke occurring in the community, with double the 30-day mortality, greater disability and diminished quality of life among survivors. Considering the annual volume of surgeries performed worldwide, perioperative stroke represents a substantial burden. Despite notable differences in aetiology, patient populations and clinical settings, existing clinical recommendations for perioperative stroke are extrapolated mainly from stroke in the community. Perioperative in-hospital stroke is unique with respect to the stroke occurring in other settings, and it is essential to apply evidence from other settings with caution and to identify existing knowledge gaps in order to effectively guide patient care and future research.

Risk of Mortality Following Surgery in Patients With a Previous Cardiovascular Event

There is a lack of consensus regarding the interval of time-dependent postoperative mortality risk following acute coronary syndrome or stroke. To determine the magnitude and duration of risk associated with the time interval between a preoperative cardiovascular event and 30-day postoperative mortality. This is a longitudinal retrospective population-based cohort study. This study linked data from the Hospital Episode Statistics for National Health Service England, Myocardial Ischaemia National Audit Project and the Office for National Statistics mortality registry. All adults undergoing a National Health Service-funded noncardiac, nonneurologic surgery in England between April 1, 2007, and March 31, 2018, registered in Hospital Episode Statistics Admitted Patient Care were included. Data were analyzed from July 2021 to July 2022. The time interval between a previous cardiovascular event (acute coronary syndrome or stroke) and surgery. The primary outcome was 30-day all-cause mortality. Secondary outcomes were postoperative mortality at 60, 90, and 365 days. Multivariable logistic regression models with restricted cubic splines were used to estimate adjusted odds ratios. There were 877 430 patients with and 20 582 717 without a prior cardiovascular event (overall mean [SD] age, 53.4 [19.4] years; 11 577 157 [54%] female). Among patients with a previous cardiovascular event, the time interval associated with increased risk of postoperative mortality was surgery within 11.3 months (95% CI, 10.8-11.7), with subgroup risks of 14.2 months before elective surgery (95% CI, 13.3-15.3) and 7.3 months for emergency surgery (95% CI, 6.8-7.8). Heterogeneity in these timings was noted across many surgical specialties. The time-dependent risk intervals following stroke and myocardial infarction were similar, but the absolute risk was greater following a stroke. Regarding surgical urgency, the risk of 30-day mortality was higher in those with a prior cardiovascular event for emergency surgery (adjusted hazard ratio, 1.35; 95% CI, 1.34-1.37) and an elective procedure (adjusted hazard ratio, 1.83; 95% CI, 1.78-1.89) than those without a prior cardiovascular event. In this study, surgery within 1 year of an acute coronary syndrome or stroke was associated with increased postoperative mortality before reaching a new baseline, particularly for elective surgery. This information may help clinicians and patients balance deferring the potential benefits of the surgery against the desire to avoid increased mortality from overly expeditious surgery after a recent cardiovascular event.

Role of Blood-Brain Barrier Dysfunction in Delirium following Non-cardiac Surgery in Older Adults.

Although animal models suggest a role for blood-brain barrier dysfunction in postoperative delirium-like behavior, its role in postoperative delirium and postoperative recovery in humans is unclear. Thus, we evaluated the role of blood-brain barrier dysfunction in postoperative delirium and hospital length of stay among older surgery patients. Cognitive testing, delirium assessment, and cerebrospinal fluid and blood sampling were prospectively performed before and after non-cardiac, non-neurologic surgery. Blood-brain barrier dysfunction was assessed using the cerebrospinal fluid-to-plasma albumin ratio (CPAR). Of 207 patients (median age = 68 years, 45% female) with complete CPAR and delirium data, 26 (12.6%) developed postoperative delirium. Overall, CPAR increased from before to 24 hours after surgery (median change = 0.28, interquartile range [IQR] = -0.48 to 1.24, Wilcoxon p = 0.001). Preoperative to 24 hours postoperative change in CPAR was greater among patients who developed delirium versus those who did not (median [IQR] = 1.31 [0.004 to 2.34] vs 0.19 [-0.55 to 1.08], p = 0.003). In a multivariable model adjusting for age, baseline cognition, and surgery type, preoperative to 24 hours postoperative change in CPAR was independently associated with delirium occurrence (per CPAR increase of 1, odds ratio = 1.30, 95% confidence interval [CI] = 1.03-1.63, p = 0.026) and increased hospital length of stay (incidence rate ratio = 1.15, 95% CI = 1.09-1.22, p < 0.001). Postoperative increases in blood-brain barrier permeability are independently associated with increased delirium rates and postoperative hospital length of stay. Although these findings do not establish causality, studies are warranted to determine whether interventions to reduce postoperative blood-brain barrier dysfunction would reduce postoperative delirium rates and hospital length of stay. ANN NEUROL 2023;94:1024-1035.

EEG pre-burst suppression: characterization and inverse association with preoperative cognitive function in older adults.

The most common complication in older surgical patients is postoperative delirium (POD). POD is associated with preoperative cognitive impairment and longer durations of intraoperative burst suppression (BSup) - electroencephalography (EEG) with repeated periods of suppression (very low-voltage brain activity). However, BSup has modest sensitivity for predicting POD. We hypothesized that a brain state of lowered EEG power immediately precedes BSup, which we have termed "pre-burst suppression" (preBSup). Further, we hypothesized that even patients without BSup experience these preBSup transient reductions in EEG power, and that preBSup (like BSup) would be associated with preoperative cognitive function and delirium risk. Data included 83 32-channel intraoperative EEG recordings of the first hour of surgery from 2 prospective cohort studies of patients ≥age 60 scheduled for ≥2-h non-cardiac, non-neurologic surgery under general anesthesia (maintained with a potent inhaled anesthetic or a propofol infusion). Among patients with BSup, we defined preBSup as the difference in 3-35 Hz power (dB) during the 1-s preceding BSup relative to the average 3-35 Hz power of their intraoperative EEG recording. We then recorded the percentage of time that each patient spent in preBSup, including those without BSup. Next, we characterized the association between percentage of time in preBSup and (1) percentage of time in BSup, (2) preoperative cognitive function, and (3) POD incidence. The percentage of time in preBSup and BSup were correlated (Spearman's ρ [95% CI]: 0.52 [0.34, 0.66], p < 0.001). The percentage of time in BSup, preBSup, or their combination were each inversely associated with preoperative cognitive function (β [95% CI]: -0.10 [-0.19, -0.01], p = 0.024; -0.04 [-0.06, -0.01], p = 0.009; -0.04 [-0.06, -0.01], p = 0.003, respectively). Consistent with prior literature, BSup was significantly associated with POD (odds ratio [95% CI]: 1.34 [1.01, 1.78], p = 0.043), though this association did not hold for preBSup (odds ratio [95% CI]: 1.04 [0.95, 1.14], p = 0.421). While all patients had ≥1 preBSup instance, only 20.5% of patients had ≥1 BSup instance. These exploratory findings suggest that future studies are warranted to further study the extent to which preBSup, even in the absence of BSup, can identify patients with impaired preoperative cognition and/or POD risk.

Perioperative changes in neurocognitive and Alzheimer's disease-related cerebrospinal fluid biomarkers in older patients randomised to isoflurane or propofol for anaesthetic maintenance

BackgroundAnimal studies have shown that isoflurane and propofol have differential effects on Alzheimer's disease (AD) pathology and memory, although it is unclear whether this occurs in humans. MethodsThis was a nested randomised controlled trial within a prospective cohort study; patients age ≥60 yr undergoing noncardiac/non-neurological surgery were randomised to isoflurane or propofol for anaesthetic maintenance. Cerebrospinal fluid (CSF) was collected via lumbar puncture before, 24 h, and 6 weeks after surgery. Cognitive testing was performed before and 6 weeks after surgery. Nonparametric methods and linear regression were used to evaluate CSF biomarkers and cognitive function, respectively. ResultsThere were 107 subjects (54 randomised to isoflurane and 53 to propofol) who completed the 6-week follow-up and were included in the analysis. There was no significant effect of anaesthetic treatment group, time, or group-by-time interaction for CSF amyloid-beta (Aβ), tau, or phospho-tau181p levels, or on the tau/Aβ or p-tau181p/Aβ ratios (all P>0.05 after Bonferroni correction). In multivariable-adjusted intention-to-treat analyses, there were no significant differences between the isoflurane and propofol groups in 6-week postoperative change in overall cognition (mean difference [95% confidence interval]: 0.01 [–0.12 to 0.13]; P=0.89) or individual cognitive domains (P>0.05 for each). Results remained consistent across as-treated and per-protocol analyses. ConclusionsIntraoperative anaesthetic maintenance with isoflurane vs propofol had no significant effect on postoperative cognition or CSF Alzheimer's disease-related biomarkers within 6 weeks after noncardiac, non-neurological surgery in older adults. Clinical trial registrationNCT01993836.

Hypertriglyceridemia is associated with stroke after non-cardiac, non-neurological surgery in the older patients: A nested case-control study

Geriatric postoperative stroke is a rare but serious complication after surgery. The association between hypertriglyceridemia and postoperative stroke remains controversial, especially in older patients undergoing non-cardiac, non-neurological surgery. The study aims to address this clinical dilemma. We conducted a nested case-control study among 9601 aged patients undergoing non-cardiac non-neurological surgery from October 2015 to 2021. A total of 22 positive cases were matched for the surgical type and time, to 88 control patients by a ratio of 1:4. The effect of hypertriglyceridemia on the occurrence of postoperative stroke within 30 days after surgery was estimated using conditional logistic regression analysis by adjusting to various potential confounders. A total of 22 cases developed ischemia stroke after surgery, and compared with the non-stroke group, they had more postoperative ICU admission, longer postoperative hospitalization and higher total cost (all p < 0.05), and more patients were presenting with preoperative hypertriglyceridemia [8 (36.4%) vs. 15 (17.0%), p = 0.045]. There was a significant association between hypertriglyceridemia and postoperative stroke, with adjusted odds ratios of 6.618 (95% CI 1.286, 34.064) (p = 0.024). The above results remained robust in the sensitivity analyses. Among older patients undergoing non-cardiac and non-neurological surgery, hypertriglyceridemia was associated with significant increased risk of postoperative stroke.

A Descriptive Cross-Sectional Study on the Incidence, Risk Factor and Outcome of Delirium in Surgical Patients in the Semi-Closed Intensive Care Unit

Introduction: There is a variation in risk factors and outcome of delirium in surgical patients in different studies. This study was conducted to determine the incidence, risk factors, and outcome of delirium in the surgical semiclosed intensive care unit in a developing country. Materials and Methods: This descriptive study was done in 82 patients of age≥18 years that underwent non-neurological surgery and admitted for more than 24 hours in a level three intensive care unit of medical college from January 10, 2021 to January 9, 2022. The whole sampling method was used in our study. The Confusion Assessment Method-ICU and Richmond Agitation Sedation Scale were used to diagnose delirium and sedation, respectively, along with a checklist to assess risk factors. All data was transferred to the excel sheet and transferred to a statistical package for the social sciences-16. Chi-square test and Fisher’s exact probability test were used to detect the difference between groups in the univariate analysis, as appropriate. The risk factors were analysed using binary logistic regression. Result: Of the 82 ICU admissions 28(34.1%) developed delirium. Hyperactive delirium was the most common motor subtype 12(42.8%). The mean duration of delirium was 4.69±5.06 days. Hypertension and alcohol were identified as risk factors for delirium. Delirious patients had a longer length of stay in the ICU (10.1 ±12.7 vs 5.1 ±4.2 days) with no impact on the duration of mechanical ventilation, mortality, reintubation, and unplanned extubation. Conclusion: Early recognition of risk factors for delirium in surgical patients can decrease the mortality and morbidity of surgical patients.

Nurse's Role in Perioperative Neurological Evaluation and Management to Lower the Risk of Acute Stroke in Patients Undergoing Noncardiac, Nonneurological Surgery

Perioperative nurses have the opportunity to play a key role in prevention and recognition of stroke in patients undergoing noncardiac, nonneurological surgery and may impact this potentially devastating complication. Effective nursing care of the older adult requires a specialized knowledge base. Scientific Statements are a cornerstone of the knowledge base that informs this care. This article summarizes the recently released American Heart Association/American Stroke Association Scientific Statement entitled: Perioperative Neurological Evaluation and Management to Lower the Risk of Acute Stroke in Patients Undergoing Noncardiac, Nonneurological Surgery and discusses the nurse's role in the care of this vulnerable patient population.

Intraoperative positive end-expiratory pressure and postoperative pulmonary complications: a patient-level meta-analysis of three randomised clinical trials

BackgroundHigh intraoperative PEEP with recruitment manoeuvres may improve perioperative outcomes. We re-examined this question by conducting a patient-level meta-analysis of three clinical trials in adult patients at increased risk for postoperative pulmonary complications who underwent non-cardiothoracic and non-neurological surgery. MethodsThe three trials enrolled patients at 128 hospitals in 24 countries from February 2011 to February 2018. All patients received volume-controlled ventilation with low tidal volume. Analyses were performed using one-stage, two-level, mixed modelling (site as a random effect; trial as a fixed effect). The primary outcome was a composite of postoperative pulmonary complications within the first week, analysed using mixed-effect logistic regression. Pre-specified subgroup analyses of nine patient characteristics and seven procedure and care-delivery characteristics were also performed. ResultsComplete datasets were available for 1913 participants ventilated with high PEEP and recruitment manoeuvres, compared with 1924 participants who received low PEEP. The primary outcome occurred in 562/1913 (29.4%) participants randomised to high PEEP, compared with 620/1924 (32.2%) participants randomised to low PEEP (unadjusted odds ratio [OR]=0.87; 95% confidence interval [95% CI], 0.75–1.01; P=0.06). Higher PEEP resulted in 87/1913 (4.5%) participants requiring interventions for desaturation, compared with 216/1924 (11.2%) participants randomised to low PEEP (OR=0.34; 95% CI, 0.26–0.45). Intraoperative hypotension was associated more frequently (784/1913 [41.0%]) with high PEEP, compared with low PEEP (579/1924 [30.1%]; OR=1.87; 95% CI, 1.60–2.17). ConclusionsHigh PEEP combined with recruitment manoeuvres during low tidal volume ventilation in patients undergoing major surgery did not reduce postoperative pulmonary complications. Clinical trial registrationNCT03937375 (Clinicaltrials.gov).

The First Derivative of the Electroencephalogram Facilitates Tracking of Electroencephalographic Alpha Band Activity During General Anesthesia.

Intraoperative neuromonitoring can help to navigate anesthesia. Pronounced alpha oscillations in the frontal electroencephalogram (EEG) appear to predict favorable perioperative neurocognitive outcomes and may also provide a measure of intraoperative antinociception. Monitoring the presence and strength of these alpha oscillations can be challenging, especially in elderly patients, because the EEG in these patients may be dominated by oscillations in other frequencies. Hence, the information regarding alpha oscillatory activity may be hidden and hard to visualize on a screen. Therefore, we developed an effective approach to improve the detection and presentation of alpha activity in the perioperative setting. We analyzed EEG records of 180 patients with a median age of 60 years (range, 18-90 years) undergoing noncardiac, nonneurologic surgery under general anesthesia with propofol induction and sevoflurane maintenance. We calculated the power spectral density (PSD) for the unprocessed EEG as well as for the time-discrete first derivative of the EEG (diffPSD) from 10-second epochs. Based on these data, we estimated the power-law coefficient κ of the PSD and diffPSD, as the EEG coarsely follows a 1/fκ distribution when displayed in double logarithmic coordinates. In addition, we calculated the alpha (7.8-12.1 Hz) to delta (0.4-4.3 Hz) ratio from the PSD as well as diffPSD. The median κ was 0.899 [first and third quartile: 0.786, 0.986] for the unaltered PSD, and κ = -0.092 [-0.202, -0.013] for the diffPSD, corresponding to an almost horizontal PSD of the differentiated EEG. The alpha-to-delta ratio of the diffPSD was strongly increased (median ratio = -8.0 dB [-10.5, -4.7 dB] for the unaltered PSD versus 30.1 dB [26.1, 33.8 dB] for the diffPSD). A strong narrowband oscillatory alpha power component (>20% of total alpha power) was detected in 23% using PSD, but in 96% of the diffPSD. We demonstrated that the calculation of the diffPSD from the time-discrete derivative of the intraoperative frontal EEG is a straightforward approach to improve the detection of alpha activity by eliminating the broadband background noise. This improvement in alpha peak detection and visualization could facilitate the guidance of general anesthesia and improve patient outcome.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Postoperative Screening With the Modified National Institutes of Health Stroke Scale After Noncardiac Surgery: A Pilot Study.

Perioperative stroke is associated with high rates of morbidity and mortality, yet there is no validated screening tool. The modified National Institutes of Health Stroke Scale (mNIHSS) is validated for use in nonsurgical strokes but is not well-studied in surgical patients. We evaluated perioperative changes in the mNIHSS score in noncardiac, non-neurological surgery patients, feasibility in the perioperative setting, and the relationship between baseline cognitive screening and change in mNIHSS score. Patients aged 65 years and above presenting for noncardiac, non-neurological surgery were prospectively recruited. Those with significant preoperative cognitive impairment (Montreal Cognitive Assessment score [MoCA] ≤17) were excluded. mNIHSS was assessed preoperatively, on postoperative day (POD) 0, POD 1, and POD 2, demographic data collected, and feedback solicited from participants. Changes in mNIHSS from baseline, time to completion, and relationship between baseline MoCA score and change in mNIHSS score were analyzed. Twenty-five patients were enrolled into the study; no overt strokes occurred. Median mNIHSS score increased between baseline (0 interquartile range [IQR 0 to 1]) and POD 0 (2 [IQR 0 to 3.5]; P<0.001) but not between baseline and POD 1 (0.5 [IQR 0 to 1.5]; P=0.174) or POD 2 (0 [IQR 0 to 1]; P=0.650). Time to complete the mNIHSS at baseline was 3.5 minutes (SD 0.8), increasing to 4.1 minutes (SD 1.0) on POD 0 (P=0.0249). Baseline MoCA score was correlated with mNIHSS score change (P=0.038). Perioperative administration of the mNIHSS was feasible, and acceptable to patients. Changes in mNIHSS score can occur early after surgery in the absence of overt stroke. Assessment of mNIHSS appears feasible in the perioperative setting, although further research is required to define its role in detecting perioperative stroke.

Perioperative Neurological Evaluation and Management to Lower the Risk of Acute Stroke in Patients Undergoing Noncardiac, Nonneurological Surgery: A Scientific Statement From the American Heart Association/American Stroke Association.

Perioperative stroke is a potentially devastating complication in patients undergoing noncardiac, nonneurological surgery. This scientific statement summarizes established risk factors for perioperative stroke, preoperative and intraoperative strategies to mitigate the risk of stroke, suggestions for postoperative assessments, and treatment approaches for minimizing permanent neurological dysfunction in patients who experience a perioperative stroke. The first section focuses on preoperative optimization, including the role of preoperative carotid revascularization in patients with high-grade carotid stenosis and delaying surgery in patients with recent strokes. The second section reviews intraoperative strategies to reduce the risk of stroke, focusing on blood pressure control, perioperative goal-directed therapy, blood transfusion, and anesthetic technique. Finally, this statement presents strategies for the evaluation and treatment of patients with suspected postoperative strokes and, in particular, highlights the value of rapid recognition of strokes and the early use of intravenous thrombolysis and mechanical embolectomy in appropriate patients.

Intraoperative hypotension and perioperative acute ischemic stroke in patients having major elective non-cardiovascular non-neurological surgery.

The association between intraoperative hypotension and perioperative acute ischemic stroke is not well described. We hypothesized that intraoperative hypotension would be associated with perioperative acute ischemic stroke. Four-year retrospective cohort study of elective non-cardiovascular, non-neurological surgical patients. Characteristics of patients who had perioperative acute ischemic stroke were compared against those of patients who did not have acute ischemic stroke. Multivariable logistic regression was used to determine whether hypotension was independently associated with increased odds of perioperative acute ischemic stroke. Thirty-four of 9816 patients (0.3%) who met study inclusion criteria had perioperative acute ischemic stroke. Stroke patients were older and had more comorbidities including hypertension, coronary artery disease, diabetes mellitus, active tobacco use, chronic obstructive pulmonary disease, cerebral vascular disease, atrial fibrillation, and peripheral vascular disease (all P < 0.05). MAP < 65mmHg was not associated with increased odds of acute ischemic stroke when modeled as a continuous or categorical variable. MAP < 60mmHg for more than 20min was independently associated with increased odds of acute ischemic stroke, OR = 2.67 [95% CI = 1.21 to 5.88, P = 0.02]. Our analysis suggests that when MAP is less than 60mmHg for more than 20min, there is increased odds of acute ischemic stroke. Further studies are needed to determine what MAP should be targeted during surgery to optimize cerebral perfusion and limit ischemic stroke risk.

Effect of Cognitive Prehabilitation on the Incidence of Postoperative Delirium Among Older Adults Undergoing Major Noncardiac Surgery

Postoperative delirium in older adults is a common and costly complication after surgery. Cognitive reserve affects the risk of postoperative delirium, and thus preoperative augmentation of reserve as a preventive technique is of vital interest. To determine whether cognitive prehabilitation reduces the incidence of postoperative delirium among older adults. This was a prospective, single-blinded randomized clinical trial conducted from March 2015 to August 2019 at the Ohio State University Wexner Medical Center in Columbus. Patients 60 years and older undergoing major, noncardiac, nonneurological surgery under general anesthesia, with an expected hospital stay of at least 72 hours, were eligible for trial inclusion. Patients were excluded for preoperative cognitive dysfunction and active depression. Participation in electronic, tablet-based preoperative cognitive exercise targeting memory, speed, attention, flexibility, and problem-solving functions. The primary outcome was incidence of delirium between postoperative day 0 to day 7 or discharge, as measured by a brief Confusion Assessment Method, Memorial Delirium Assessment Scale, or a structured medical record review. Secondary outcomes compared delirium characteristics between patients in the intervention and control groups. Of the 699 patients approached for trial participation, 322 completed consent and 268 were randomized. Subsequently, 17 patients were excluded, leaving 251 patients in the primary outcome analysis. A total of 125 patients in the intervention group and 126 control patients were included in the final analysis (median [interquartile range] age, 67 [63-71] years; 163 women [64.9%]). Ninety-seven percent of the patients in the intervention group completed some brain exercise (median, 4.6 [interquartile range, 1.31-7.4] hours). The delirium rate among control participants was 23.0% (29 of 126). With intention-to-treat analysis, the delirium rate in the intervention group was 14.4% (18 of 125; P = .08). Post hoc analysis removed 4 patients who did not attempt any cognitive exercise from the intervention group, yielding a delirium rate of 13.2% (16 of 121; P = .04). Secondary analyses among patients with delirium showed no differences in postoperative delirium onset day or duration or total delirium-positive days across study groups. The intervention lowered delirium risk in patients who were at least minimally compliant. The ideal activities, timing, and effective dosage for cognitive exercise-based interventions to decrease postoperative delirium risk and burden need further study. ClinicalTrials.gov Identifier: NCT02230605.

Neuromonitoring during general anesthesia in non-neurologic surgery.

Cerebral complications are common in perioperative settings even in non-neurosurgical procedures. These include postoperative cognitive dysfunction or delirium as well as cerebrovascular accidents. During surgery, it is essential to ensure an adequate degree of sedation and analgesia, and at the same time, to provide hemodynamic and respiratory stability in order to minimize neurological complications. In this context, the role of neuromonitoring in the operating room is gaining interest, even in the non-neurolosurgical population. The use of multimodal neuromonitoring can potentially reduce the occurrence of adverse effects during and after surgery, and optimize the administration of anesthetic drugs. In addition to the traditional focus on monitoring hemodynamic and respiratory systems during general anesthesia, the ability to constantly monitor the activity and maintenance of brain homeostasis, creating evidence-based protocols, should also become part of the standard of care: in this challenge, neuromonitoring comes to our aid. In this review, we aim to describe the role of the main types of noninvasive neuromonitoring such as those based on electroencephalography (EEG) waves (EEG, Entropy module, Bispectral Index, Narcotrend Monitor), near-infrared spectroscopy (NIRS) based on noninvasive measurement of cerebral regional oxygenation, and Transcranial Doppler used in the perioperative settings in non-neurosurgical intervention. We also describe the advantages, disadvantage, and limitation of each monitoring technique.