Multicentre validation of a machine learning model for predicting respiratory failure after noncardiac surgery.

BACKGROUND: Postoperative respiratory failure is a serious complication that could benefit from early accurate identification of high-risk patients. We developed and validated a machine learning model to predict postoperative respiratory failure, defined as prolonged (>48 h) mechanical ventilation or reintubation after surgery. METHODS: Easily extractable electronic health record (EHR) variables that do not require subjective assessment by clinicians were used. From EHR data of 307,333 noncardiac surgical cases, the model, trained with a gradient boosting algorithm, utilised a derivation cohort of 99,025 cases from Seoul National University Hospital (2013-9). External validation was performed using three separate cohorts A-C from different hospitals comprising 208,308 cases. Model performance was assessed by area under the receiver operating characteristic (AUROC) curve and area under the precision-recall curve (AUPRC), a measure of sensitivity and precision at different thresholds. RESULTS: The model included eight variables: serum albumin, age, duration of anaesthesia, serum glucose, prothrombin time, serum creatinine, white blood cell count, and body mass index. Internally, the model achieved an AUROC of 0.912 (95% confidence interval [CI], 0.908-0.915) and AUPRC of 0.113. In external validation cohorts A, B, and C, the model achieved AUROCs of 0.879 (95% CI, 0.876-0.882), 0.872 (95% CI, 0.870-0.874), and 0.931 (95% CI, 0.925-0.936), and AUPRCs of 0.029, 0.083, and 0.124, respectively. CONCLUSIONS: Utilising just eight easily extractable variables, this machine learning model demonstrated excellent discrimination in both internal and external validation for predicting postoperative respiratory failure. The model enables personalised risk stratification and facilitates data-driven clinical decision-making.

High Intraoperative Serum Lactate Level is Associated with Acute Kidney Injury after Brain Tumor Resection.

BACKGROUND: Postoperative acute kidney injury (AKI) is associated with poor clinical outcomes. Identification of risk factors for postoperative AKI is clinically important. Serum lactate can increase in situations of inadequate oxygen delivery and is widely used to assess a patient's clinical course. We investigated the association between intraoperative serum lactate levels and AKI after brain tumor resection. METHODS: Demographics, medical and surgical history, tumor characteristics, surgery, anesthesia, preoperative and intraoperative blood test results, and postoperative clinical outcomes were retrospectively collected from 4131 patients who had undergone brain tumor resection. Patients were divided into high (n=1078) and low (n=3053) lactate groups based on an intraoperative maximum serum lactate level of 3.35 mmol/L. After propensity score matching, 1005 patients were included per group. AKI was diagnosed using the Kidney Disease Improving Global Outcomes criteria, based on serum creatinine levels within 7 days after surgery. RESULTS: Postoperative AKI was observed in 53 (1.3%) patients and was more frequent in those with high lactate both before (3.2% [n=35] vs. 0.6% [n=18]; P < 0.001) and after (3.3% [n=33] vs. 0.6% [n=6]; P < 0.001) propensity score matching. Intraoperative predictors of postoperative AKI were maximum serum lactate levels > 3.35 mmol/L (odds ratio [95% confidence interval], 3.57 [1.45-8.74], P = 0.005), minimum blood pH (odds ratio per 1 unit, 0.01 [0.00-0.24], P = 0.004), minimum hematocrit (odds ratio per 1%, 0.91 [0.84-1.00], P = 0.037), and mean serum glucose levels > 200 mg/dL (odds ratio, 6.22 [1.75-22.16], P = 0.005). CONCLUSION: High intraoperative serum lactate levels were associated with AKI after brain tumor resection.

Erratum: Correction of Affiliations in the Article "Preoperative Prognostic Nutritional Index Is a Prognostic Indicator of Cancer-Specific Survival in Patients Undergoing Endometrial Cancer Surgery".

This corrects the article on p. e163 in vol. 38, PMID: 37270918.

The Warburg effect in patients with brain tumors: a comprehensive analysis of clinical significance.

PURPOSE: The Warburg Effect, referring to an elevation in serum lactate level attributable to increased tumor metabolism, is present in patients with brain tumors. This study comprehensively analyzes the Warburg effect in patients undergoing brain tumor resection. METHODS: We retrospectively analyzed the baseline intraoperative serum lactate levels of 2,053 patients who underwent craniotomies, including 415 with cerebral aneurysms and 1,638 with brain tumors. The brain tumor group was divided into subgroups based on the tumor pathology (extra-axial and intra-axial tumor) and the WHO tumor grade (high-grade and low-grade). RESULTS: Serum lactate level was significantly higher in the tumor group than in the aneurysm group (1.98 ± 0.97 vs. 1.09 ± 0.57 mmol/L, p < 0.001). The hyperlactatemia incidence (serum lactate level > 2.2 mmol/L) was higher in the tumor group (33.5 vs. 3.1%, p < 0.001). Severe hyperlactatemia (serum lactate level > 4.4 mmol/L) was found in 34 patients (2.1%) of only the tumor group. In patients with intra-axial tumors, serum lactate level was greater in high- than low-grade tumors (2.10 ± 1.05 vs. 1.88 ± 0.92 mmol/L, p = 0.006). Factors predictive of hyperlactatemia included supratentorial tumor location (odds ratio[95%CI] 2.926[2.127-4.025], p < 0.001) and a long tumor diameter (1.071[1.007-1.139], p = 0.028). In high-grade intra-axial brain tumor patients, there was a significant difference in overall survival between patients with hyperlactatemia than those without (p = 0.048). CONCLUSION: Our results show that brain tumor patients exhibit the Warburg effect and serum lactate may be a useful diagnostic and prognostic biomarker in patients with high-grade intra-axial brain tumors.

Autonomic responses during bladder hydrodistention under general versus spinal anaesthesia in patients with interstitial cystitis/bladder pain syndrome: a randomized clinical trial.

Blocking the abrupt increase in systolic blood pressure associated with autonomic response during bladder hydrodistention in patients with interstitial cystitis/bladder pain syndrome (IC/BPS) is essential for patient safety. We conducted this study to compare autonomic responses during bladder hydrodistention in patients with IC/BPS under general and spinal anaesthesia. Thirty-six patients were randomly allocated to a general anaesthesia (GA, n = 18) or a spinal anaesthesia (SA, n = 18) group. Blood pressure and heart rate were measured continuously and ΔSBP, defined as maximum increases in SBP during bladder hydrodistention from baseline, was compared between groups. Heart rate variability was analysed using electrocardiograms. The post-anaesthesia care unit assessed postoperative pain using a numeric (0-10) rating scale. Our analyses yield a significantly greater ΔSBP (73.0 [26.0-86.1] vs. 2.0 [- 4.0 to 6.0] mmHg), a significantly lower root-mean-square of successive differences in heart rate variability after bladder hydrodistention (10.8 [7.7-19.8] vs. 20.6 [15.1-44.7] ms), and significantly higher postoperative pain scores (3.5 [0.0-5.5] vs. 0.0 [0.0-0.0]) in the GA compared to the SA group. These findings suggest that SA has advantages over GA for bladder hydrodistention in preventing an abrupt increase in SBP and postoperative pain in IC/BPS patients.

Preoperative Prognostic Nutritional Index Is a Prognostic Indicator of Cancer-Specific Survival in Patients Undergoing Endometrial Cancer Surgery.

BACKGROUND: The prognostic nutritional index (PNI) reflects systemic inflammation and nutritional status. This study aimed to evaluate the effect of preoperative PNI on postoperative cancer-specific survival in patients with endometrial cancer (EC). METHODS: Demographic, laboratory, and clinical data were retrospectively collected from 894 patients who underwent surgical resection of EC. Preoperative PNIs were determined from the serum albumin concentration and total lymphocyte count, which were measured within 1 month before surgery. Patients were classified into high PNI (n = 619) and low PNI (n = 275) groups according to the preoperative PNI cut-off value of 50.6. The stabilized inverse probability of treatment weighting (IPTW) method was used to reduce bias: a weighting cohort divided into high PNI (n = 615.4) and low PNI (n = 272.3) groups. The primary outcome measure was postoperative cancer-specific survival. RESULTS: The postoperative cancer-specific survival rate was higher in the high PNI group than the low PNI group in the unadjusted cohort (93.1% vs. 81.5%; proportion difference [95% confidence interval; 95% CI], 11.6% [6.6-16.6%]; P < 0.001) and in the IPTW-adjusted cohort (91.4% vs. 86.0%; 5.4% [0.8-10.2%]; P = 0.021). In the multivariate Cox proportional hazard regression model in the IPTW-adjusted cohort, high preoperative PNI (hazard ratio [95% CI], 0.60 [0.38-0.96]; P = 0.032) was an independent determinant of postoperative cancer-specific mortality. The multivariate-adjusted restricted cubic spline curve for the Cox regression model showed a significant negative association between preoperative PNI and postoperative cancer-specific mortality (P < 0.001). CONCLUSION: High preoperative PNI was associated with improved postoperative cancer-specific survival in patients undergoing surgery for EC.

Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging for Language Mapping in Brain Tumor Surgery: Validation With Direct Cortical Stimulation and Cortico-Cortical Evoked Potential.

OBJECTIVE: Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging-derived tractography (DTI-t) contribute to the localization of language areas, but their accuracy remains controversial. This study aimed to investigate the diagnostic performance of preoperative fMRI and DTI-t obtained with a simultaneous multi-slice technique using intraoperative direct cortical stimulation (DCS) or corticocortical evoked potential (CCEP) as reference standards. MATERIALS AND METHODS: This prospective study included 26 patients (23-74 years; male:female, 13:13) with tumors in the vicinity of Broca's area who underwent preoperative fMRI and DTI-t. A site-by-site comparison between preoperative (fMRI and DTI-t) and intraoperative language mapping (DCS or CCEP) was performed for 226 cortical sites to calculate the sensitivity and specificity of fMRI and DTI-t for mapping Broca's areas. For sites with positive signals on fMRI or DTI-t, the true-positive rate (TPR) was calculated based on the concordance and discordance between fMRI and DTI-t. RESULTS: Among 226 cortical sites, DCS was performed in 100 sites and CCEP was performed in 166 sites. The specificities of fMRI and DTI-t ranged from 72.4% (63/87) to 96.8% (122/126), respectively. The sensitivities of fMRI (except for verb generation) and DTI-t were 69.2% (9/13) to 92.3% (12/13) with DCS as the reference standard, and 40.0% (16/40) or lower with CCEP as the reference standard. For sites with preoperative fMRI or DTI-t positivity (n = 82), the TPR was high when fMRI and DTI-t were concordant (81.2% and 100% using DCS and CCEP, respectively, as the reference standards) and low when fMRI and DTI-t were discordant (≤ 24.2%). CONCLUSION: fMRI and DTI-t are sensitive and specific for mapping Broca's area compared with DCS and specific but insensitive compared with CCEP. A site with a positive signal on both fMRI and DTI-t represents a high probability of being an essential language area.

Effects of Scalp Nerve Block on the Quality of Recovery after Minicraniotomy for Clipping of Unruptured Intracranial Aneurysms : A Randomized Controlled Trial.

OBJECTIVE: This study compared the quality of recovery (QoR) after minicraniotomy for clipping of unruptured intracranial aneurysms (UIAs) between patients with and without scalp nerve block (SNB). METHODS: Patients were randomly assigned to the SNB (SNB using ropivacaine with epinephrine, n=27) and control (SNB using normal saline, n=25) groups. SNB was performed at the end of surgery. To assess postoperative QoR, the QoR-40, a patient-reported questionnaire, was used. The QoR-40 scores were measured preoperatively, 1-3 days postoperatively, at hospital discharge, and 1 month postoperatively. Pain and intravenous patient-controlled analgesia (IV-PCA) consumption were evaluated 3, 6, 9, and 12 hours and 1-3 days postoperatively. RESULTS: All QoR-40 scores, including those measured 1 day postoperatively (primary outcome measure; 155.0 [141.0-176.0] vs. 161.0 [140.5-179.5], p=0.464), did not significantly differ between the SNB and control groups. The SNB group had significantly less severe pain 3 (numeric rating scale [NRS]; 3.0 [2.0-4.0] vs. 5.0 [3.5-5.5], p=0.029), 9 (NRS; 3.0 [2.0-4.0] vs. 4.0 [3.0-5.0], p=0.048), and 12 (NRS; 3.0 [2.0-4.0] vs. 4.0 [3.0-5.0], p=0.035) hours postoperatively. The total amount of IV-PCA consumed was significantly less 3 hours postoperatively in the SNB group (2.0 [1.0-4.0] vs. 4.0 [2.0-5.0] mL, p=0.044). CONCLUSION: After minicraniotomy for clipping of UIAs, SNB reduced pain and IV-PCA consumption in the early postoperative period but did not improve the QoR-40 scores.

The antioxidant effect of preischemic dexmedetomidine in a rat model: increased expression of Nrf2/HO-1 via the PKC pathway

Abstract Background The precise underlying mechanism of antioxidant effects of dexmedetomidine-induced neuroprotection against cerebral ischemia has not yet been fully elucidated. Activation of Nuclear factor erythroid 2-related factor (Nrf2) and Heme Oxygenase-1 (HO-1) represents a major antioxidant-defense mechanism. Therefore, we determined whether dexmedetomidine increases Nrf2/HO-1 expression after global transient cerebral ischemia and assessed the involvement of Protein Kinase C (PKC) in the dexmedetomidine-related antioxidant mechanism. Methods Thirty-eight rats were randomly assigned to five groups: sham (n = 6), ischemic (n = 8), chelerythrine (a PKC inhibitor; 5 mg.kg-1 IV administered 30 min before cerebral ischemia) (n = 8), dexmedetomidine (100 µg.kg-1 IP administered 30 min before cerebral ischemia (n = 8), and dexmedetomidine + chelerythrine (n = 8). Global transient cerebral ischemia (10 min) was applied in all groups, except the sham group; histopathologic changes and levels of nuclear Nrf2 and cytoplasmic HO-1 were examined 24 hours after ischemia insult. Results We found fewer necrotic and apoptotic cells in the dexmedetomidine group relative to the ischemic group (p< 0.01) and significantly higher Nrf2 and HO-1 levels in the dexmedetomidine group than in the ischemic group (p< 0.01). Additionally, chelerythrine co-administration with dexmedetomidine attenuated the dexmedetomidine-induced increases in Nrf2 and HO-1 levels (p< 0.05 and p< 0.01, respectively) and diminished its beneficial neuroprotective effects. Conclusion Preischemic dexmedetomidine administration elicited neuroprotection against global transient cerebral ischemia in rats by increasing Nrf2/HO-1 expression partly via PKC signaling, suggesting that this is the antioxidant mechanism underlying dexmedetomidine-mediated neuroprotection.

A cost-utility analysis between decompression only and fusion surgery for elderly patients with lumbar spinal stenosis and sagittal imbalance.

Lumbar spinal stenosis (LSS) and sagittal imbalance are relatively common in elderly patients. Although the goals of surgery include both functional and radiological improvements, the criteria of correction may be too strict for elderly patients. If the main symptom of patients is not forward-stooping but neurogenic claudication or pain, lumbar decompression without adding fusion procedure may be a surgical option. We performed cost-utility analysis between lumbar decompression and lumbar fusion surgery for those patients. Elderly patients (age > 60 years) who underwent 1-2 levels lumbar fusion surgery (F-group, n = 31) or decompression surgery (D-group, n = 40) for LSS with sagittal imbalance (C7 sagittal vertical axis, C7-SVA > 40 mm) with follow-up ≥ 2 years were included. Clinical outcomes (Euro-Quality of Life-5 Dimensions, EQ-5D; Oswestry Disability Index, ODI; numerical rating score of pain on the back and leg, NRS-B and NRS-L) and radiological parameters (C7-SVA; lumbar lordosis, LL; the difference between pelvic incidence and lumbar lordosis, PI-LL; pelvic tilt, PT) were assessed. The quality-adjusted life year (QALY) and incremental cost-effective ratio (ICER) were calculated from a utility score of EQ-5D. Postoperatively, both groups attained clinical and radiological improvement in all parameters, but NRS-L was more improved in the F-group (p = 0.048). ICER of F-group over D-group was 49,833 US dollars/QALY. Cost-effective lumbar decompression may be a recommendable surgical option for certain elderly patients, despite less improvement of leg pain than with fusion surgery.

Sevoflurane anesthesia rather than propofol anesthesia is associated with 3-month postoperative hypocortisolism in patients undergoing endoscopic transsphenoidal surgery for non-functional pituitary adenoma with preoperative normal hypothalamic-pituitary-adrenal axis.

PURPOSE: The effects of anesthetic technique on intermediate-term postoperative adrenocorticotropic hormone (ACTH) functional outcomes have not been fully determined in non-functioning pituitary adenoma (NFPA) patients. Postoperative hypocortisolism is potentially life-threatening and requires steroid replacement after pituitary surgery. The present study determined whether sevoflurane anesthesia was predictive of 3-month postoperative hypocortisolism in NFPA patients with preoperative normal hypothalamic-pituitary-adrenal (HPA) axis. METHODS: Demographics, preoperative pituitary hormone status, intraoperative data, and tumor characteristics were retrospectively collected from 429 NFPA patients, who had preoperative normal HPA axis and underwent endoscopic transsphenoidal surgery. Patients were divided into two groups based on intraoperative anesthetic technique: sevoflurane-based inhalation anesthesia group (n = 74) and propofol-based intravenous anesthesia group (n = 355). After propensity score matching, 73 patients were selected in each group and the incidence of 3-month postoperative hypocortisolism (primary outcome measure) was compared between the two groups. RESULTS: The incidence of 3-month postoperative hypocortisolism was higher in the sevoflurane anesthesia group than the propofol anesthesia group before (n = 20[27.0%] vs. n = 49[13.8%], P = 0.008) and after (n = 20 [27.4%] vs. n = 5 [6.8%], P = 0.002) propensity score matching, respectively. Sevoflurane anesthetic use (odds ratio [95% CI] 5.37[1.80-15.98], P = 0.003) and postoperative steroid administration (2.89 [1.06-7.92], P = 0.039) were predictors of 3-month postoperative hypocortisolism. CONCLUSION: In patients with preoperative normal HPA axis undergoing endoscopic transsphenoidal surgery for NFPA, sevoflurane anesthesia and postoperative steroid administration were associated with the development of 3-month postoperative hypocortisolism. A large-scale prospective study is needed to confirm the negative association between sevoflurane anesthesia and postoperative ACTH functional outcome.

Preservation of language function by mapping the arcuate fasciculus using intraoperative corticocortical evoked potential under general anesthesia in glioma surgery.

OBJECTIVE: Intraoperative language mapping under general anesthesia is imperative for brain tumor surgery because awake surgery is not always feasible. Monitoring corticocortical evoked potential (CCEP) is known to be a useful method for tracking neuronal connectivity and localizing functional areas. The authors evaluated the clinical benefit of intraoperative CCEP monitoring for language function preservation in patients undergoing glioma surgery. METHODS: Between January 2019 and June 2021, the authors performed a total of 29 consecutive glioma surgeries using CCEP monitoring under general anesthesia because of a risk of speech impairment; these were analyzed. Language area mapping was implemented by the anterior language area to posterior language area CCEP method for arcuate fasciculus mapping, and tumor resection was performed while avoiding the localized language areas. Language function before and after surgery was evaluated by the Controlled Oral Word Association Test (COWAT). RESULTS: Intraoperative CCEP was successfully monitored in 25 patients (86.2%), and a valid signal was undetectable in the other 4 patients. Language function evaluation was possible before and after surgery in a total of 20 patients. Overall, the preservation rate of language function was 65.0%, and the deterioration rate was 35.0% after tumor resection with CCEP monitoring. Among those 8 patients with preoperative COWAT scores ≥ 18, 5 patients (62.5%) successfully preserved their language function, with COWAT scores > 18 after tumor resection. Among the 12 patients with preoperative deteriorated language function (COWAT score < 18), 8 patients (66.7%) showed improvement or preserved language function after surgery. CONCLUSIONS: Intraoperative CCEP monitoring of the arcuate fasciculus is an acceptable technology for the preservation of language function under general anesthesia in glioma surgery in patients in whom awake surgery is not feasible.

Intraarterial catheter diameter and dynamic response of arterial pressure monitoring system: a randomized controlled trial.

The dynamic response (DR) of the arterial pressure monitoring system (APMS) may depend on the intraarterial catheter (IAC) diameter. We hypothesized that adequate DR would be more common when using a smaller IAC. We compared the DR of the AMPS (Auto Transducer™) between three IACs (BD Angiocath Plus™) with different diameters. 353 neurosurgical patients were randomized into three groups undergoing catheterization with a 20-, 22-, or 24-gauge IAC: 20G (n = 119), 22G (n = 117), and 24G (n = 117) groups, respectively. The DR, which depends on the natural frequency and damping coefficient, was divided into four types: adequate (primary outcome measure), underdamped, overdamped, and unacceptable. The frequency of intraoperative IAC malfunction was noted. Adequate DR was observed more frequently in the 22G and 24G groups than the 20G group (13.7% and 15.4% vs. 4.2%, P = 0.011 and 0.004, respectively). The frequency of underdamped DR was higher in the 20G group than the 24G group (86.6% vs. 69.2%, P = 0.001), whereas overdamped DR was more frequent in the 24G group than the 20G and 22G groups (6.0% vs. 0.0% and 0.0%, P = 0.007 and 0.014, respectively). IAC malfunctioned more frequently during surgery in the 24G group than the 20G and 22G groups (15.4% vs. 0.0% and 1.7%, P < 0.001 and P < 0.001, respectively). The frequency of adequate DR was low regardless of the IAC diameter. Nonetheless, in terms of DR and IAC malfunction, a 22-gauge BD Angiocath Plus™ was more suitable for invasive blood pressure monitoring with Auto Transducer™ than a 20- or 24-gauge BD Angiocath Plus™. Registration Registry: ClinicalTrials.gov. Registration number: NCT03642756. Date of Registration: July 27, 2018.

Radiographic Predictors of Difficult McGrath MAC Videolaryngoscopy in Patient Undergoing Cervical Spine Surgery.

BACKGROUND: McGrath MAC videolaryngoscopy is a useful technique for successful intubation in cervical spine-injured patients with manual in-line stabilization of the neck during intubation. We aimed to identify radiographic predictors of difficult McGrath MAC videolaryngoscopy in patient undergoing cervical spine surgery. METHODS: Patients undergoing cervical spine surgery who were intubated with a McGrath MAC videolaryngoscope under manual in-line stabilization of the neck between June 2016 and August 2018 were included in this study. Data on airway-related variables and radiographic indices obtained from preoperative lateral cervical spine x-ray, magnetic resonance imaging, and computed tomography (CT) scans were retrospectively collected. Patients were divided into difficult and easy McGrath MAC videolaryngoscopic intubation groups on the basis of intubation time and the number of intubation attempts. RESULTS: In total, 183 patients were included in the study of which 33 (18%) showed difficult videolaryngoscopic intubation. In multivariate logistic regression analysis, atlanto-occipital distance (odds ratio [OR], 0.74; 95% confidence interval [CI], 0.62-0.89; P=0.001) on lateral cervical spine x-ray, incisor-C1-C6 angle in neck extension on lateral cervical spine x-ray (OR, 1.12; 95% CI, 1.02-1.22; P=0.015), tongue area/oral cavity area ratio in the mid-sagittal plane of cervical magnetic resonance imaging or computed tomography (OR, 1.12; 95% CI, 1.05-1.19; P<0.001), and interincisor gap (OR, 0.92; 95% CI, 0.86-0.98; P=0.015) were independent risk factors for difficult videolaryngoscopic intubation. CONCLUSIONS: Radiographic variables indicating enlarged tongue relative to the oral cavity and limited neck extension were associated with difficult McGrath MAC videolaryngoscopy in patients undergoing cervical spine surgery with manual in-line cervical stabilization during intubation.

Prognostic significance of the postoperative prognostic nutritional index in patients with glioblastoma: a retrospective study.

BACKGROUND: The prognostic nutritional index (PNI) reflects immunonutritional status. We evaluated the effects of postoperative PNI and perioperative changes in the PNI on overall survival (OS) in glioblastoma (GBM) patients. METHODS: Demographic, laboratory, and clinical data were retrospectively collected from 335 GBM patients. Preoperative and postoperative PNIs were calculated from serum albumin concentration and lymphocyte count, which were measured within 3 weeks before surgery and 1 month after surgery. Patients were classified into high (n = 206) or low (n = 129) postoperative PNI groups according to the postoperative PNI cutoff value and further classified into four groups according to the cutoff values of the preoperative and postoperative PNIs, as follows: Group HH (both high PNIs, n = 92), Group HL (high preoperative and low postoperative PNI, n = 70), Group LH (low preoperative and high postoperative PNI, n = 37), and Group LL (both low PNIs, n = 136). RESULTS: The median OS was significantly longer in the high postoperative PNI (PNI ≥ 50.2) group than the low postoperative PNI (PNI < 50.2) group (24.0 vs. 15.0 months, p <  0.001). In multivariate analysis, high postoperative PNI was a significant predictor of OS. OS was significantly longer in Group HH than in Group LL and seemed longer in Group HH than in Group HL and in Group LH than in Group LL. OS was not different between Groups HH and LH or between Groups HL and LL. CONCLUSIONS: High postoperative PNI was associated with improved OS and perioperative changes in PNI may provide additional important information for prognostic prediction in GBM patients.

Clinical outcome prediction from analysis of microelectrode recordings using deep learning in subthalamic deep brain stimulation for Parkinson`s disease.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for improving the motor symptoms of advanced Parkinson's disease (PD). Accurate positioning of the stimulation electrodes is necessary for better clinical outcomes. OBJECTIVE: We applied deep learning techniques to microelectrode recording (MER) signals to better predict motor function improvement, represented by the UPDRS part III scores, after bilateral STN DBS in patients with advanced PD. If we find the optimal stimulation point with MER by deep learning, we can improve the clinical outcome of STN DBS even under restrictions such as general anesthesia or non-cooperation of the patients. METHODS: In total, 696 4-second left-side MER segments from 34 patients with advanced PD who underwent bilateral STN DBS surgery under general anesthesia were included. We transformed the original signal into three wavelets of 1-50 Hz, 50-500 Hz, and 500-5,000 Hz. The wavelet-transformed MER was used for input data of the deep learning. The patients were divided into two groups, good response and moderate response groups, according to DBS on to off ratio of UPDRS part III score for the off-medication state, 6 months postoperatively. The ratio were used for output data in deep learning. The Visual Geometry Group (VGG)-16 model with a multitask learning algorithm was used to estimate the bilateral effect of DBS. Different ratios of the loss function in the task-specific layer were applied considering that DBS affects both sides differently. RESULTS: When we divided the MER signals according to the frequency, the maximal accuracy was higher in the 50-500 Hz group than in the 1-50 Hz and 500-5,000 Hz groups. In addition, when the multitask learning method was applied, the stability of the model was improved in comparison with single task learning. The maximal accuracy (80.21%) occurred when the right-to-left loss ratio was 5:1 or 6:1. The area under the curve (AUC) was 0.88 in the receiver operating characteristic (ROC) curve. CONCLUSION: Clinical improvements in PD patients who underwent bilateral STN DBS could be predicted based on a multitask deep learning-based MER analysis.

A Retrospective Observational Study of the Neuroendocrine Stress Response in Patients Undergoing Endoscopic Transsphenoidal Surgery for Removal of Pituitary Adenomas: Total Intravenous Versus Balanced Anesthesia.

BACKGROUND: Anesthetic technique affects the neuroendocrine stress response to surgery. In this retrospective study, we compared the neuroendocrine stress response in patients undergoing endoscopic transsphenoidal pituitary adenoma surgery (ETSPAS) with total intravenous anesthesia (TIVA) with propofol-remifentanil or balanced anesthesia (BAL) with sevoflurane-remifentanil. MATERIALS AND METHODS: Eighty-nine patients undergoing ETSPAS were anesthetized with either propofol-remifentanil (TIVA group, n=62) or sevoflurane-remifentanil (BAL group, n=27). Data were retrospectively collected regarding preoperative and immediate postoperative serum levels of adrenocorticotropic hormone (ACTH) and cortisol (primary outcome measures), as well as other pituitary hormones and their target organ hormones (secondary outcome measures). RESULTS: There were no significant differences in preoperative pituitary hormone levels between the 2 groups. The immediate postoperative ACTH (89.5 [62.1 to 162.6] vs. 256.0 [92.0 to 570.7] pg/mL; P<0.001) level was lower in the TIVA group than in the BAL group, whereas immediate postoperative cortisol levels were similar between the 2 groups. The immediate postoperative thyroid-stimulating hormone (1.85 [1.21 to 2.98] vs. 1.21 [0.44 to 1.71] µIU/mL; P=0.003), triiodothyronine (91.0 [82.0 to 103.0] vs. 69.1 [64.6 to 76.2] ng/dL; P<0.001), luteinizing hormone (2.2 [1.2 to 4.0] vs. 1.0 [0.5 to 2.3] mIU/mL; P=0.005), and prolactin (22.6±15.8 vs. 12.8±10.2 ng/mL; P=0.005) levels were higher in the TIVA group compared with the BAL group. In both groups, none of the patients who had sufficient preoperative ACTH without hydrocortisone supplementation (n=15) showed hypocortisolism in the immediate postoperative measurement. CONCLUSIONS: Compared with BAL, TIVA resulted in reduced release of ACTH and increased release of thyroid-stimulating hormone, triiodothyronine, luteinizing hormone, and prolactin in patients undergoing ETSPAS.

Cephalocaudal tumor diameter is a predictor of diabetes insipidus after endoscopic transsphenoidal surgery for non-functioning pituitary adenoma.

PURPOSE: Diabetes insipidus (DI) develops commonly after endoscopic transsphenoidal surgery (ETS). We retrospectively investigated the incidence, onset, duration and predictors of DI after ETS in patients with non-functioning pituitary adenoma (NFPA). METHODS: A total of 168 patients who underwent ETS to remove NFPAs were included. Various perioperative data on demographics, comorbidities, previous treatments, perioperative hormone deficiencies, tumor characteristics, surgery, anesthesia, intraoperative fluid balance, perioperative laboratory findings, postoperative complications, readmission and hospital length of stay were collected and analyzed. Patients were diagnosed with DI and treated with desmopressin when they showed urine output > 5 mL/kg/hr with a serum sodium concentration > 145 mmol/L or an increase ≥ 3 mmol/L in serum sodium concentration between two consecutive tests after surgery. DI was considered permanent when desmopressin was prescribed for > 6 months after surgery. RESULTS: Seventy-seven (45.8%) patients experienced postoperative DI and 10 (6.0%) patients suffered from permanent DI. The median onset of DI and the median duration of transient DI were postoperative day 1 and 5 days, respectively. In multivariable logistic regression analysis, cephalocaudal tumor diameter (odds ratio [95% confidence interval] 2.59 [1.05-6.36], P = 0.038) was related to postoperative DI. In receiver operating characteristic analysis, its area under the curve was 0.68 (95% confidence interval 0.59-0.76, P < 0.001). Its optimal cutoff value that maximized the sum of sensitivity and specificity for postoperative DI was 2.7 cm. CONCLUSIONS: Postoperative DI was observed in 45.8% of patients undergoing ETS to remove NFPAs. A large cephalocaudal tumor diameter was predictive of postoperative DI in such patients.

Randomized crossover trial comparing cervical spine motion during tracheal intubation with a Macintosh laryngoscope versus a C-MAC D-blade videolaryngoscope in a simulated immobilized cervical spine.

BACKGROUND: Maintaining cervical immobilization is essential during tracheal intubation in patients with unstable cervical spines. When using the Macintosh laryngoscope for intubation in patients with cervical immobilization, substantial neck extension is required for visualization of the glottis. However, the C-MAC D-Blade videolaryngoscope may require less neck extension due to its acute angulation. We hypothesized that C-MAC D-Blade videolaryngoscopic intubation would result in less cervical spine movement than Macintosh laryngoscopic intubation. We compared the effects of C-MAC D-Blade videolaryngoscopic intubation and Macintosh laryngoscopic intubation in terms of cervical spine motion during intubation in patients with simulated cervical immobilization. METHODS: In this randomized crossover study, the cervical spine angle was measured at the occiput-C1, C1-C2, and C2-C5 segments before and during tracheal intubation with either a C-MAC D-Blade videolaryngoscope or Macintosh laryngoscope in 20 patients, with application of a neck collar for simulated cervical immobilization. Cervical spine motion was defined as the change in angle measured before and during tracheal intubation. RESULTS: The cervical spine motion at the occiput-C1 segment was measured at 12.1 ± 4.2° and 6.8 ± 5.0° during Macintosh laryngoscopic and C-MAC D-blade videolaryngoscopic intubation, respectively, corresponding to a 44% reduction in cervical spine motion when using the latter device (mean difference, - 5.3; 98.33% CI: - 8.8 to - 1.8; p = 0.001). However, there was no significant difference between the two intubation devices at the C1-C2 segment (- 0.6; 98.33% CI: - 3.4 to 2.2; p = 0.639) or C2-C5 segment (0.2; 98.33% CI: - 6.0 to 6.4; p = 0.929). CONCLUSIONS: The C-MAC D-Blade videolaryngoscope causes less upper cervical spine motion than the Macintosh laryngoscope during tracheal intubation of patients with simulated cervical immobilization. TRIAL REGISTRATION: This study was registered at ClinicalTrials.gov on June 26, 2018 ( NCT03567902 ).