Preoperative Salivary Cortisol AM/PM Ratio Predicts Early Postoperative Cognitive Dysfunction After Noncardiac Surgery in Elderly Patients

Association between serum chemokines levels and delayed neurocognitive recovery after non-cardiac surgery in elderly patients: a nested case-control study

BACKGROUND

Perioperative neurocognitive disorders encompass delayed neurocognitive recovery (dNCR). Emerging evidence suggests that chemokines play a crucial role in the pathogenesis of various cognitive impairment diseases. However, the association between chemokines and dNCR remains unclear. Therefore, we aimed to investigate the relationship between serum chemokine levels and dNCR in elderly patients undergoing non-cardiac surgery.

METHODS

A total of 144 patients undergoing elective major non-cardiac surgery were accessed in neuropsychological testing 1 day prior to and 1 week following the surgery. Blood samples were collected before the initiation of anesthesia and one hour following the cessation of anesthesia. We employed a retrospective nested case-control study design, utilizing one control per dNCR case. Matching criteria included age (± 5 years), duration of surgery (± 90 min), and baseline MMSE score (± 3). We compared the serum levels of CCL2, CCL5, CCL11, and CXCL8 between the matched dNCR and non-dNCR groups.

RESULTS

dNCR was observed in 31.25% (45 of 144) of the patients seven days post-surgery, resulting in a final matched sample size of 21 pairs. In the preoperative comparison, the serum concentration of CCL11 was significantly higher in the matched dNCR group compared to the matched non-dNCR group (P = 0.039). In the postoperative comparison, the CCL5 concentration was significantly lower in the dNCR than in the non-dNCR group (P = 0.030). When comparing the differences between postoperative and preoperative levels, the absolute change in CCL11 was significantly greater in the dNCR group compared to the non-dNCR group (P = 0.046). Additionally, the postoperative-to-preoperative ratios of CCL5 and CCL11 in the dNCR group were both significantly lower than those in the non-dNCR group (P = 0.046, P = 0.005). There were no significant differences in CCL2 or CXCL8 levels between the two matched groups.

CONCLUSIONS

Serum levels of CCL 5 and CCL 11 significantly decreased in elderly patients with dNCR following non-cardiac surgery, which may contribute to the identification of patients at high risk for dNCR.

TRIAL REGISTRATION

This study was registered on chictr.org.cn (ChiCTR1800014473, 16/01/2018).

Melanin-Concentrating Hormone Is Associated With Delayed Neurocognitive Recovery in Older Adult Patients With Preoperative Sleep Disorders Undergoing Spinal Anesthesia

BACKGROUND

Aging and preoperative sleep disorders are the main risk factors affecting postoperative cognitive outcomes. However, the pathogenesis of delayed neurocognitive recovery after surgery remains ambiguous, and there is still a lack of potential biomarkers for delayed neurocognitive recovery in older adult patients with preoperative sleep disorders. Our study aimed to explore the relationship between melanin-concentrating hormone (MCH) and delayed neurocognitive recovery early after surgery in older adult patients with preoperative sleep disorders.

METHODS

In this monocentric prospective observational study, 156 older adult patients (aged 65 years or older) with preoperative sleep disorders undergoing elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) were included at an academic medical center in Inner Mongolia, China, from October 2021 to November 2022, and all patients underwent spinal anesthesia. The Pittsburgh Sleep Quality Index (PSQI) was applied to assess the preoperative sleep quality of all patients, and preoperative sleep disorders were defined as a score of PSQI >5. We measured the levels of cerebrospinal fluid (CSF) MCH and plasma MCH of all patients. The primary outcome was delayed neurocognitive recovery early after surgery. All patients received cognitive function assessment through the Montreal Cognitive Assessment (MoCA) 1 day before and 7 days after surgery (postoperative day 7 [POD7]). Delayed neurocognitive recovery was defined as a score of POD7 MoCA <26. The potential confounders included variables with P < .2 in the univariate logistic analysis, as well as the important risk factors of delayed neurocognitive recovery reported in the literature. Multivariable logistic regression model based on the Enter method assessed the association of MCH and delayed neurocognitive recovery in older adult patients with preoperative sleep disorders.

RESULTS

Fifty-nine (37.8%) older adult patients with preoperative sleep disorders experienced delayed neurocognitive recovery at POD7. Increase in CSF MCH levels (odds ratio [OR] for an increase of 1 pg/mL = 1.16, 95% confidence interval [CI], 1.09-1.23, P < .001) and decrease in plasma MCH levels (OR for an increase of 1 pg/mL = 0.92, 95% CI, 0.86-0.98, P = .003) were associated with delayed neurocognitive recovery, after adjusting for age, sex, education, baseline MoCA scores, American Society of Anesthesiologists (ASA) grade, and coronary heart disease (CHD).

CONCLUSIONS

In older adult patients with preoperative sleep disorders, MCH is associated with the occurrence of delayed neurocognitive recovery after surgery. Preoperative testing of CSF MCH or plasma MCH may increase the likelihood of identifying the high-risk population for delayed neurocognitive recovery in older adult patients with preoperative sleep disorders.

The relationship between longer leukocyte telomeres and dNCR in non-cardiac surgery patients: a retrospective analysis

BACKGROUND

Cognitive decline following surgery is a common concern among elderly individuals. Leukocyte telomere length (LTL) can be assessed as a biological clock connected to an individual lifespan. However, the mechanisms causing this inference are still not fully understood. As a result of this, LTL has the potential to be useful as an aging-related biomarker for assessing delayed neurocognitive recovery (dNCR) and related diseases.

METHODS

For this study, 196 individuals over 60 who were scheduled due to major non-cardiac surgical operations attended neuropsychological testing before surgery, followed by additional testing one week later. The finding of dNCR was based on a measured Z-score ≤ -1.96 on two or more separate tests. The frequency of dNCR was presented as the primary outcome of the study. Secondly, we evaluated the association between dNCR and preoperative LTL.

RESULTS

Overall, 20.4% [40/196; 95% confidence interval (CI), 14.7-26.1%] of patients exhibited dNCR 1-week post-surgery. Longer LTL was identified as a predictor for the onset of early cognitive impairment resulting in postoperative cognitive decline [odds ratio (OR), 14.82; 95% CI, 4.01-54.84; P < 0.001], following adjustment of age (OR, 12.33; 95% CI, 3.29-46.24; P < 0.001). The dNCR incidence based on LTL values of these patients, the area under the receiver operating characteristic (ROC) curve was 0.79 (95% CI, 0.722-0.859; P < 0.001). At an optimal cut-off value of 0.959, LTL values offered respective specificity and sensitivity values of 64.7% and 87.5%.

CONCLUSIONS

In summary, the current study revealed that the incidence of dNCR was strongly associated with prolonged LTL. Furthermore, this biomarker could help identify high-risk patients and offer insight into the pathophysiology of dNCR.

Predicative factors and development of a nomogram for postoperative delayed neurocognitive recovery in elderly patients with gastric cancer

BACKGROUND

Delayed neurocognitive recovery (DNR) is a common complication after radical gastrectomy and closely associated with poor outcomes. This study aimed to investigate predictors and develop a nomogram prediction model for DNR.

METHODS

Elderly gastric cancer (GC) patients (≥ 65 years) undergoing elective laparoscopic radical gastrectomy between 2018 and 2022 were prospectively included in this study. DNR was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V, 2013). Independent risk factors for DNR were screened by the multivariate logistic regression analysis. Based on these factors, the nomogram model was established and validated by R.

RESULTS

A total of 312 elderly GC patients were enrolled in the training set, with an incidence of DNR within postoperative 1 month of 23.4% (73/312). Multivariate logistic regression analysis indicated that age (OR: 1.207, 95%CI: 1.113-1.309, P < 0.001), nutritional risk screening 2002 (NRS2002) score (OR: 1.716, 95%CI: 1.211-2.433, P = 0.002), neutrophil-to-lymphocyte ratio (NLR) (OR: 1.976, 95%CI: 1.099-3.552, P = 0.023), albumin-to-fibrinogen ratio (AFR) (OR: 0.774, 95%CI: 0.620-0.966, P = 0.024), and prognostic nutritional index (PNI) (OR: 0.768, 95%CI: 0.706-0.835, P < 0.001) were five independent factors for DNR in elderly GC patients. The constructed nomogram model based on these five factors has a good predictive value for DNR with an area under the curve (AUC) of 0.863.

CONCLUSIONS

In conclusions, the established nomogram model based on age, NRS-2002, NLR, AFR, and PNI has a well predictive value for postoperative DNR in elderly GC patients.

Effect of Subanesthetic Dose of Esketamine on Perioperative Neurocognitive Disorders in Elderly Undergoing Gastrointestinal Surgery: A Randomized Controlled Trial

BACKGROUND

Perioperative neurocognitive disorders (PND), including delayed neurocognitive recovery (dNCR) and postoperative cognitive dysfunction (POCD), are common postoperative complications in elderly patients and adversely affect their prognosis. The study was designed to explore the effects of esketamine on postoperative cognitive function in elderly patients who underwent gastrointestinal surgery under general anesthesia and its potential mechanism.

METHODS

Eighty-four patients aged 65 and above undergoing gastrointestinal surgery were randomly divided into 2 groups: the esketamine group (group S) and the control group (group C). Group S received intravenous sub-anesthetic doses of esketamine (0.15 mg/kg) 5 minutes before the initiation of surgery, while group C received the same volume of saline. A battery of neuropsychological tests was used to assess cognitive function before surgery, 7 days, and 3 months after surgery. The primary outcome was the incidence of dNCR at 7 days postoperatively and POCD at 3 months postoperatively in both groups. The secondary outcome measures included changes in the levels of serum interleukin-6 (IL-6) and calcium-binding protein β (S100β) before and 1 day after surgery.

RESULTS

The incidence of dNCR in group S was lower than that of group C (18.15% vs 38.24% P=0.033). Contrarily, there was no difference in both groups regarding POCD 3 months postoperatively (6.06% vs 14.37% P=0.247). Plasma IL-6 and S100β levels were significantly elevated in both groups on postoperative day 1 (p<0.05), but esketamine pretreatment reduced these levels to some extent compared with group C (p<0.05).

CONCLUSION

Sub-anesthetic doses of esketamine might reduce the incidence of dNCR and improve early postoperative cognitive function in elderly patients undergoing gastrointestinal surgery, which might be related to the anti-neuroinflammation effects of esketamine.

Cognitive function in older patients and their stress challenge using different anesthesia regimes: a single center observational study

BACKGROUND

With increasing age older patients are at higher risk for cognitive decline after surgery. Even tailored anesthesia procedures in older patients remain a high risk for postoperative cognitive disorder. Additional stress derived from anxiety and anesthesia itself can negatively impact postoperative cognitive outcomes. The objective of this study was to evaluate the impact of general versus regional anesthesia on postoperative cognitive disorder and indicators of perioperative stress in elderly undergoing surgery.

METHODS

In this single center prospective study between December 2014 and November 2015, 46 patients aged 50 to 85 years undergoing dermatology surgery were enrolled. Patients were stratified by receiving general versus regional nerve anesthesia. On three consecutive days, saliva cortisol levels were analyzed three times per day. Cognitive function was assessed on the day before and the day after surgery using comprehensive neuropsychological testing of multiple cognitive functions including memory, executive function, attention and processing speed.

RESULTS

Comparing the regional anesthesia group (RAG, n = 28) with the general anesthesia group (GAG, n = 18) no significant difference in the postoperative cognitive function was observed. However, patients in the GAG had significantly higher postoperative cortisol levels when compared to patients in the RAG. In both groups, a peak of cortisol value was detected on the day of surgery, which was higher in the GAG in comparison to the RAG.

CONCLUSIONS

We did not observe a difference in postoperative cognitive function between patients undergoing regional or general anesthesia for dermatology surgery. However, we found lower cortisol level in the RAG. Based on these findings, future studies should investigate alternatives to reduce stress in a general anesthesia setting.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT02505815.

Anesthesia and surgery-induced elevation of CSF sTREM2 is associated with early cognitive dysfunction after thoracoabdominal aortic dissection surgery

PURPOSE

Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) concentration is increased in cerebrospinal fluid (CSF) in early symptomatic phase of Alzheimer's disease (AD). This study investigated whether CSF sTREM2 has a relationship with early cognitive dysfunction following surgery in cardiac surgery patients.

METHODS

A total of 82 patients undergoing thoracoabdominal aortic replacement were recruited in this study. Neuropsychological testing battery was conducted before and after surgery. Postoperative cognitive dysfunction (POCD) was defined as a Z-score > 1.96 on at least 2 different tests or Telephone Interviews for Cognitive Status-Modified (TICS-M) score < 27. The CSF and serum sTREM2, Aβ₄₂, T-tau and P-tau were collected and measured by ELISA on day before surgery and postoperative day 3.

RESULTS

Patients were classified into POCD (n = 34) and non-POCD (n = 48) groups according to Z-score. Compared to non-POCD group, the levels of CSF sTREM2 (p < 0.001) and serum sTREM2 (p = 0.001) were significantly higher in POCD group on postoperative day 3. The levels of Aβ₄₂ (p = 0.005) and Aβ₄₂/T-tau ratio (p = 0.036) were significantly lower in POCD group on postoperative day 3. Multivariate logistic regression analysis revealed that higher value of postoperative CSF sTREM2 (odds ratio: 1.06, 95% confidence interval: 1.02-1.11, p = 0.009), age (OR: 1.15, 95%CI: 1.03-1.28, p = 0.014) and POD duration (OR: 2.47, 95%CI: 1.15-5.29, p = 0.02) were the risk factors of POCD.

CONCLUSION

This study indicates that anesthesia and surgery-induced elevation of CSF sTREM2 is associated with an increased risk of early cognitive dysfunction following surgery.

Association between preoperative serum homocysteine and delayed neurocognitive recovery after non-cardiac surgery in elderly patients: a prospective observational study

BACKGROUND

Homocysteine, folate, and vitamin B₁₂ involved in 1-carbon metabolism are associated with cognitive disorders. We sought to investigate the relationships between these factors and delayed neurocognitive recovery (dNCR) after non-cardiac surgery.

METHODS

This was a prospective observational study of patients (n = 175) who were ≥ 60 years of age undergoing non-cardiac surgery. Patients were evaluated preoperatively and for 1 week postoperatively by using neuropsychological tests and were divided into dNCR or non-dNCR groups according to a Z-score ≤ - 1.96 on at least two of the tests. The relationship between the occurrence of dNCR and preoperative levels of homocysteine, folate, and vitamin B₁₂ was analyzed. Univariate and multivariable logistic regression analyses were conducted to identify factors associated with dNCR.

RESULTS

Delayed neurocognitive recovery was observed in 36 of 175 patients (20.6%; 95% confidence interval [CI], 14.5-26.6%) 1 week postoperatively. Patients who developed dNCR had significantly higher median [interquartile range (IQR)] homocysteine concentrations (12.8 [10.9,14.4] μmol/L vs 10.6 [8.6,14.7] μmol/L; P = 0.02) and lower folate concentrations (5.3 [4.2,7.3] ng/mL vs 6.9 [5.3,9.5] ng/mL; P = 0.01) than those without dNCR. Compared to the lowest tertile, the highest homocysteine tertile predicted dNCR onset (odds ratio [OR], 3.9; 95% CI, 1. 3 to 11.6; P = 0.02), even after adjusting for age, sex, education, and baseline Mini Mental State Examination.

CONCLUSIONS

Elderly patients with high homocysteine levels who underwent general anesthesia for non-cardiac surgery have an increased risk of dNCR. This knowledge could potentially assist in the development of preventative and/or therapeutic measures.

TRIAL REGISTRATION

NCT03084393 ( https://www.clinicaltrials.gov ).

Preoperative laboratory testing in elderly patients

PURPOSE OF REVIEW

Preoperative testing in elderly patients is performed to examine the patient's current medical condition in the context of evaluating vulnerabilities and predicting postoperative complications to ensure that all functions recover before surgery. This review focused on preoperative laboratory tests in geriatric patients.

RECENT FINDINGS

Preoperative complete blood count, electrolyte testing, and blood chemistry can predict postoperative complications. Preoperative elevated morning/evening salivary cortisol secretion ratio, C-reactive protein/albumin ratio (CAR), neutrophil/lymphocyte ratios, and preoperative decreased serum albumin level or 25-hydroxyvitamin D levels can predict postoperative cognitive dysfunction. Elevated brain-type natriuretic peptide or serum alkaline phosphatase levels can be biomarkers of major postoperative adverse cardiac events. Decreased preoperative estimated glomerular filtration rates and serum albumin levels can predict acute kidney injury. Hyponatremia, hypocalcemia, and low albumin/fibrinogen ratio predict postoperative complications. Hypoalbuminemia can predict surgical site infection or postoperative mortality after hip fracture surgery. A high CAR can predict anastomotic site leakage and is a risk factor for one-year mortality after hip surgery.

SUMMARY

Preoperative laboratory testing helps predict postoperative adverse complications; thus, a plan of care can be initiated.

[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.

Diagnostic Criteria of Postoperative Cognitive Dysfunction: A Focused Systematic Review

Postoperative Cognitive Dysfunction (POCD) is characterized by a deterioration in cognitive performance after surgery and is increasingly addressed in research studies. However, a uniform definition of POCD seems to be lacking, which is a major threat to clinical research in this area. We performed a focused systematic review to determine the current degree of heterogeneity in how POCD is defined across studies and to identify those diagnostic criteria that are used most commonly. The search identified 173 records, of which 30 were included. Neurocognitive testing was most commonly performed shortly before surgery and at 7 days postoperatively. A variety of neurocognitive tests were used to test a range of cognitive domains, including complex attention, language, executive functioning, perceptual-motor function, and learning and memory. The tests that were used most commonly were the Mini-Mental State Examination, the digit span test, the trail making test part A, and the digit symbol substitution test, but consensus on which test result would be considered “positive” for POCD was sparse. The results of this systematic review suggest the lack of a consistent approach towards defining POCD. However, commonalities were identified which may serve as a common denominator for deriving consensus-based diagnostic guidelines for POCD.

Dexmedetomidine improves early postoperative neurocognitive disorder in elderly male patients undergoing thoracoscopic lobectomy

Perioperative neurocognitive disorder (PND) is a common complication following thoracic surgery that frequently occurs in patients ≥65 years. PND includes postoperative cognitive dysfunction (POCD) and postoperative delirium (POD). To investigate whether intravenous dexmedetomidine (DEX) is able to improve neurocognitive function in elderly male patients following thoracoscopic lobectomy, a randomized, double-blinded, placebo-controlled trial was performed at the Affiliated Hospital of Inner Mongolia Medical University (Hohhot, China). Patients aged ≥65 years were enrolled and were subjected to thoracic surgery under general anesthesia. A computer-generated randomization sequence was used to randomly assign patients (at a 1:1 ratio) to receive either intravenous DEX (0.5 µg/kg per h, from induction until chest closure) or placebo (intravenous normal saline). The primary endpoint was the result of the Mini-Mental State Examination (MMSE). The secondary endpoints were the results of the Montreal Cognitive Assessment (MoCA) and those obtained with the Confusion Assessment Method (CAM), as well as the incidence of POCD and POD during the first 7 postoperative days. Other observational indexes included sleep quality at night, self-anxiety scale prior to the operation and 7 days following the operation and the visual analogue scale (VAS) score at rest and during movement on the first and third day following the operation. Furthermore, at 6 h following surgery, the MMSE score in the DEX group was significantly higher than that in the saline group. At 6 h and on the first day postoperatively, the MoCA score in the DEX group was significantly higher than that in the saline group. The incidence of POCD and POD in the DEX group was 13.2 and 7.5%, respectively, while that in the saline group was 35.8 and 11.3%, respectively. There was a significant difference in the incidence of POCD between the two groups (P<0.01). In the DEX group, mean sleep quality was increased, whereas the mean VAS was decreased compared with the corresponding values in the saline group. In conclusion, elderly male patients who underwent thoracoscopic lobectomy under continuous infusion of DEX (0.5 µg/kg/h) exhibited a reduced incidence of POCD during the first 7 postoperative days as compared with the placebo group. Furthermore, DEX improved the subjective sleep quality in the first postoperative night, reduced anxiety and alleviated postoperative pain. In addition, it increased the incidence of bradycardia. The present study was registered in the Chinese Clinical Trial Registry (www.chictr.org.cn; registration no. ChiCTR-IPR-17010958).

Preoperative neutrophil-lymphocyte ratio, an independent risk factor for postoperative cognitive dysfunction in elderly patients with gastric cancer

AIM

This study aimed to investigate the potential risk factors for postoperative cognitive dysfunction (POCD) in elderly patients with gastric cancer (GC) after radical gastrectomy.

METHODS

In total, 221 elderly patients with GC who were scheduled to undergo selective radical gastrectomy in our hospital were enrolled in this study. To define early POCD, the neuropsychological assessment was carried out 1 day before surgery and 7 days after surgery. Receiver operating characteristic curve analysis was carried out to evaluate the predicative and cut-off values of risk factors, including neutrophil-lymphocyte ratio (NLR) for early POCD. The univariate and multivariate logistic regression analyses were performed to investigate risk factors for early POCD.

RESULTS

Of the 221 enrolled elderly patients with GC, 42 were identified as early POCD with an incidence of 19.0% (42 of 221). Receiver operating characteristic curve analysis indicated that NLR was a significant predictor for POCD with a cut-off value of 2.50 and an area under the curve of 0.711 (95% confidence interval: 0.624-0.798, P < 0.001). Preoperative NLR (≥2.50) was the only independent risk factor associated with POCD (odds ratio: 2.44, 95% confidence interval: 1.52-3.68, P = 0.013) by the multivariate logistic regression analysis.

CONCLUSIONS

Preoperative NLR level was an independent risk factor for POCD in elderly patients with GC undergoing curative resection. Geriatr Gerontol Int 2020; 20: 927-931.

Is hospitalisation a risk factor for cognitive decline in the elderly?

PURPOSE OF REVIEW

Cognitive decline is frequently reported after hospitalisation in the contexts of surgery, delirium and critical care. The question not adequately addressed is whether all types of acute hospitalisations increase the risk of cognitive decline. As acute hospitalisations are common in the elderly, who are also vulnerable to cognitive decline, this possible association is of significant concern.

RECENT FINDINGS

This review summarises cognitive outcomes from recent observational studies investigating acute hospitalisation (emergent and elective) in older age adults. Studies were identified from searching Medline, Embase and PsycINFO databases and citations lists. The highest incidence of cognitive decline has been reported following critical care admissions and admissions complicated by delirium, although all types of acute hospitalisations are implicated. Age is the most consistent risk factor for cognitive decline. Several etiological and therapeutic aspects are being investigated, particularly the measurement of inflammatory biomarkers and treatment with anti-inflammatory medications.

SUMMARY

Acute hospitalisation for any reason appears to increase the risk of cognitive decline in older adults, but the cause remains elusive. Future research must clarify the nature and modifiers of posthospitalisation cognitive change, a priority in the face of an ageing population.

Neuroanesthesiology Update

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.