Analgesia Nociception Index (ANI) as a monitor of peri-operative nociception-antinociception balance in paediatric craniotomies: a prospective observational study.

INTRODUCTION: Analgesia Nociception Index (ANI) as a monitor of peri-operative nociception-anti-nociception balance has not been studied in paediatric neurosurgery. The objectives were to study the correlation between ANI (Mdoloris Education system) and revised FLACC (r-FLACC) score for the prediction of acute postoperative pain in paediatric population undergoing elective craniotomies and to compare the changes in ANI values with heart rate (HR), mean arterial pressure (MAP) and surgical plethysmographic index (SPI) during various time points of intraoperative noxious stimulation and before and after opioid administration. METHODS: This prospective observational pilot study included 14 patients between 2 and 12 years of age undergoing elective craniotomies. HR, MAP, SPI, ANI instantaneous (ANIi) and ANI mean (ANIm) values were recorded intraoperatively and before and after opioid administration. Postoperatively HR, MAP, ANIi and ANIm, and pain scores (r-FLACC scale) were recorded. RESULTS: There was a statistically significant negative correlation between ANIi and ANIm with r-FLACC during the time course of PACU stay (r = - 0.89, p < 0.001 and r = - 0.88 and p < 0.001 respectively). Intraoperatively, in patients with ANIi values < 50, with additional fentanyl administration, there was an increasing trend in values beyond 50, which was statistically significant (p < 0.05) at 3, 4, 5 and 10 min. The trend in changes of SPI after opioid administration was not found to be significant for patients irrespective of the baseline SPI values. CONCLUSION: The ANI is a reliable tool for objective assessment of acute postoperative pain as assessed by r-FLACC in children undergoing craniotomies for intracranial lesions. It may be used as a guide to nociception-antinociception balance during the peri-operative period in this population.

Postoperative delirium after intracranial neurosurgery: A prospective cohort study from a developing nation.

INTRODUCTION: Post-operative delirium (POD) is a major complication after anesthesia and surgery with an incidence varying from 5 to 50%. The incidence of POD after intracranial surgery is likely to be higher due to the pre-existing brain pathology and direct handling of the brain during neurosurgery. The primary objective of this study was to assess the incidence of POD after intracranial neurosurgery and our secondary objective was to identify the potential risk factors for its occurrence. MATERIALS AND METHODS: This prospective observational study was conducted after the institutional ethics committee approval between october 2020 and march 2021. We included patients of either gender aged ≥ 18 years and undergoing elective intracranial neurosurgery. Exclusion criteria included patients aged below 18 years, undergoing emergency neurosurgery, patients with impaired consciousness and patients with psychiatric comorbidities or those taking psychotropic medications. We planned to exclude patients from analysis who were transferred to intensive care unit (ICU) or if they were not extubated after surgery. Our study outcome was development of POD as assessed by confusion assessment method (CAM). RESULTS: The overall incidence of POD during the three postoperative days was 19.2% (n=60/313). The incidence of POD on days 1, 2, and 3 were 19.2% (n=60/313), 17.2% (n=50/291), and 16.3% (n=39/239). Preoperative delirium and hyperactive Emergence Delirium were found to be the significant predictors of POD. CONCLUSION: Every one in five patients undergoing intracranial neurosurgery is vulnerable for the development of POD within first three days after surgery. The incidence of occurrence of POD is time-sensitive and is decremental.

Clinical Scoring and Ultrasound-Based Diaphragm Assessment in Predicting Extubation Failure in Neurointensive Care Unit: A Single-Center Observational Study.

BACKGROUND: Patients in the neurointensive care unit (NICU) fail extubation despite successful weaning from mechanical ventilation. Parameters currently used in the general intensive care unit do not accurately predict extubation success in the NICU. In this study, peak cough expiratory flow rate, ultrasound-based diaphragm function assessment, and comprehensive clinical scoring systems were measured to determine whether these new variables, in isolation or combination, could predict extubation failure successfully in the NICU. METHODS: All adult patients extubated after 48 h of mechanical ventilation in the NICU of a single tertiary care center were recruited into the prospective cohort. The patient's cough peak expiratory flow rate (C-PEFR), diaphragm function, and clinical scores were measured before extubation. C-PEFR was measured using a hand-held spirometer, diaphragm function (excursion, thickness fraction, and diaphragm contraction velocity on coughing) was assessed using ultrasound, and the clinical scores included the visual pursuit, swallowing, age, Glasgow Coma Scale for extubation (VISAGE) and respiratory insufficiency scale-intubated (RIS-i) scores. The patients requiring reintubation within 48 h were considered as extubation failure. Univariate and multivariate logistic regression analyses were done to identify predictors of extubation failure. RESULTS: Of the 193 patients screened, 43 were recruited, and 15 had extubation failure (20.9%). Patients with extubation failure had higher RIS-i scores (p < 0.001) and lower VISAGE scores (p = 0.043). The C-PEFR and diaphragm function (excursions and contraction velocity on coughing) were lower in patients with extubation failure but not statistically significant. The variables with p < 0.2 in univariate analysis (RIS-i, VISAGE, and diaphragm cough velocity) were subjected to multivariate regression analysis. RIS-I score remained an independent predictor (odds ratio 3.691, 95% confidence interval 1.5-8.67, p = 0.004). In a receiver operating characteristic analysis, the area under the curve for RIS-i was 0.963. An RIS-i score of 2 or more had 94% specificity and 89% sensitivity for predicting extubation failure. CONCLUSIONS: The RIS-i score predicts extubation failure in NICU patients. The addition of ultrasound-based diaphragm measurements to the RIS-i score to improve prediction accuracy needs further study. Clinical trial registration Clinical Trials Registry of India identifier CTRI/2021/03/031923.

Utility of 3D T1-weighted turbo spin echo black blood sequence for the diagnosis of cerebral venous thrombosis.

PURPOSE: Accurate assessment of dural sinus, deep and cortical venous thrombosis on MR imaging is challenging. The aim of this study is to evaluate the accuracy of 3D-T1 turbo spin echo (T1S), sequences in detecting venous thrombosis and comparing it with susceptibility-weighted imaging (SWI), magnetic resonance venography (MRV) and post contrast T1 magnetization-prepared rapid acquisition gradient echo (T1C). METHODS: A blinded retrospective observational analysis of 71 consecutive patients evaluated for cerebral venous thrombosis (CVT) and 30 control patients was performed. Multimodality reference standard adopted included T1C, SWI with MRV. Sub-analyses in superficial, deep and cortical venous segments were performed in addition to correlation of signal intensity of thrombus with the clinical stage. RESULTS: A total of 2222 segments in 101 complete MRI examinations were evaluated. Sensitivity/specificity/positive predictive value/negative predictive value/accuracy and precision of T1S for detection of cortical vein thrombosis was 0.994/1/1/0.967/0.995/1, 1/0.874/0.949/1/0.963/0.950 for detection of superficial venous sinus thrombosis and 1/1/1/1/1/1 for deep venous thrombosis. The AUC yield for T1S was 0.997 for cortical, 1 for deep and 0.988 for superficial venous segments. CONCLUSION: T1S paralleled the accuracy of conventional sequences in the overall detection of CVT but showed superior accuracy in the detection of cortical venous thrombosis. It makes a fitting addition to the CVT MRI protocol in scenarios demanding negation of gadolinium administration.

The Effect of Pharmacologically Induced Blood Pressure Manipulation on Cardiac Output and Cerebral Blood Flow Velocity in Patients with Aneurysmal Subarachnoid Hemorrhage.

Background: Vasopressors are used in patients with subarachnoid hemorrhage (SAH) to increase blood pressure with the idea of reversing the ischemic process. The current study is designed to evaluate the changes in systemic and cerebral hemodynamics, including cerebral blood flow autoregulation, at different pharmacologically augmented blood pressure levels using norepinephrine in patients with spontaneous aneurysmal SAH following surgery. Materials and methods: This prospective observational study was carried out in patients with ruptured anterior circulation aneurysms who underwent surgical clipping and required norepinephrine infusion. Postoperatively, when the treating physician decided to start a vasopressor, norepinephrine infusion was started at 0.05 µg/kg/min. The infusion rate was increased by 0.05 µg/kg/min every 5 minutes to achieve a 20% and then 40% increase in the systolic blood pressure (SBP). When the blood pressure stabilized at each level for 5 minutes, hemodynamic and transcranial doppler (TCD) parameters in the middle cerebral artery (MCA) were recorded. Results: Peak systolic, end-diastolic, and mean flow velocities in the MCA increased with targeted blood pressure increase in the hemispheres with impaired autoregulation and not in the hemispheres with intact autoregulation. The interaction of changes in TCD flow velocities between hemispheres with and without intact autoregulation was significant (p < 0.001). Cardiac output changes following norepinephrine infusion were not significant (p = 0.113). Conclusion: Hypertensive therapy with norepinephrine increases cerebral blood flow velocity only when autoregulation is impaired, an effect that is desirable in patients with focal cerebral ischemia following SAH. How to cite this article: Lakshmegowda M, Muthuchellapan R, Sharma M, Ganne SUR, Chakrabarti D, Muthukalai S. The Effect of Pharmacologically Induced Blood Pressure Manipulation on Cardiac Output and Cerebral Blood Flow Velocity in Patients with Aneurysmal Subarachnoid Hemorrhage. Indian J Crit Care Med 2023;27(4):254-259.

The requirement of propofol for induction of anesthesia in patients with traumatic brain injury determined using bilateral bispectral index and target controlled infusion - An observational cohort study.

Background and Aims: Patients with traumatic brain injury (TBI) frequently require emergency surgery. There is a paucity of literature with regard to anesthetic requirements in these patients. The aim of the study was to compare the dose of propofol required for induction of anesthesia in patients with different grades of TBI. Material and Methods: This prospective, observational study included patients with mild, moderate, and severe grades of TBI undergoing emergency surgery within 48 h of injury. Bispectral Index (BIS) values were recorded using a bilateral BIS sensor. Anesthesia was induced with a target controlled infusion (TCI) pump. Once BIS reached 40, plasma (Cp) and effect-site (Ce) concentration and total dose of propofol required were noted from the TCI pump. Results: Of the 96 patients recruited, 27, 36, and 33 patients belonged to mild, moderate, and severe TBI (sTBI) groups, respectively. The Ce of propofol in mild, moderate, and sTBI groups was 6 ± 0.9, 5.82 ± 0.98, and 4.48 ± 1.5 µg/mL (P < 0.001), and the dose of propofol required was 1.9 ± 0.2, 1.8 ± 0.4, 1.41 ± 0.5 mg/kg, respectively (P < 0.001). Baseline BIS on the injured side was 80 ± 7.8, 71 ± 9.4, 55 ± 11.6, and on the uninjured side was 89 ± 5.5, 81 ± 8.4, and 65 ± 12 in mild, moderate, and sTBI groups, respectively. Conclusions: The requirement of propofol was reduced in patients with sTBI. The dose of propofol required for induction of anesthesia as determined using Ce was significantly lower only between sTBI and mild TBI and not between patients with sTBI and moderate TBI or between mild and moderate head injury. BIS values were significantly different between the groups (highest in mild TBI and lowest in sTBI) and between normal and injured sides within each group.

Diffusion and perfusion imaging biomarkers of H3 K27M mutation status in diffuse midline gliomas.

PURPOSE: H3K27M-mutant diffuse midline gliomas (M-DMGs) exhibit a clinically aggressive course. We studied diffusion-weighted imaging (DWI) and perfusion (PWI) MRI features of DMG with the hypothesis that DWI-PWI metrics can serve as biomarkers for the prediction of the H3K27M mutation status in DMGs. METHODS: A retrospective review of the institutional database (imaging and histopathology) of patients with DMG (July 2016 to July 2020) was performed. Tumoral apparent diffusion coefficient (ADC) and peritumoral ADC (PT ADC) values and their normalized values (nADC and nPT ADC) were computed. Perfusion data were analyzed with manual arterial input function (AIF) and leakage correction (LC) Boxerman-Weiskoff models. Normalized maximum relative CBV (rCBV) was evaluated. Intergroup analysis of the imaging variables was done between M-DMGs and wild-type (WT-DMGs) groups. RESULTS: Ninety-four cases (M-DMGs-n = 48 (51%) and WT-DMGs-n = 46(49%)) were included. Significantly lower PT ADC (mutant-1.1 ± 0.33, WT-1.23 ± 0.34; P = 0.033) and nPT ADC (mutant-1.64 ± 0.48, WT-1.83 ± 0.54; P = 0.040) were noted in the M-DMGs. The rCBV (mutant-25.17 ± 27.76, WT-13.73 ± 14.83; P = 0.018) and nrCBV (mutant-3.44 ± 2.16, WT-2.39 ± 1.25; P = 0.049) were significantly higher in the M-DMGs group. Among thalamic DMGs, the min ADC, PT ADC, and nADC and nPT ADC were lower in M-DMGs while nrCBV (corrected and uncorrected) was significantly higher. Receiver operator characteristic curve analysis demonstrated that PT ADC (cut-off-1.245), nPT ADC (cut-off-1.853), and nrCBV (cut-off-1.83) were significant independent predictors of H3K27M mutational status in DMGs. CONCLUSION: DWI and PWI features hold value in preoperative prediction of H3K27M-mutation status in DMGs.

Full-text publications of presentations at neuroanesthesia meetings of India: A 5-year audit and analysis.

Backgroud and Aims: Conference presentations provide an opportunity to rapidly share findings of new research despite limitations of details and reach. Earlier studies have examined publication rates of conference presentations in anesthesia. However, conversion rate of neuroanesthesia meeting presentations to publications is unknown. We assessed the publication rate of neuroanesthesia conference presentations from India over a 5-year period and identified factors contributing to subsequent publications. Material and Methods: Conference abstracts of the Indian Society of Neuroanaesthesiology and Critical Care (ISNACC) from 2014 to 2018 were studied with regard to conversion to full-length publications. Details of presentations were obtained from abstracts published in the journal of ISNACC and details of publications were collected by searching Google and PubMed using title and author details. Results: Only 17.5% (40/229) of the abstracts presented at ISNACC conferences over a 5-year period resulted in subsequent full-text publications in peer-reviewed journals. Prospective cohort studies (OR [95% CI] 2.84 [1.05-8.56], P = 0.048), randomized trials (OR [95% CI] 2.69 [1.04 to 7.9], P = 0.053), and abstracts from public institutions (OR [95% CI] 3.44 [1.4 to 10.42], P = 0.014) were significantly associated with publications after conference presentations. Conclusion: The conversion rate of conference presentations of neuroanesthesia society of India into journal publications is significantly low. There is need for neuroanesthesia community of India to work together to improve the translation of presentations into publications.

The effect of prone positioning on surgical pleth index in patients undergoing spine surgery under general anesthesia - A prospective observational study.

Background and Aims: Surgical Pleth Index (SPI) provides an objective assessment of nociception - anti-nociception balance but is influenced by multiple confounders. The effect of change of position on SPI, has not been studied extensively. The aim of the study was to observe the effect of prone positioning on SPI and its correlation with hemodynamic variables, in patients undergoing lumbar and thoracic spine surgery. Material and Methods: This prospective observational pilot study included 14 patients. In addition to hemodynamic monitoring, SPI, entropy and pulse pressure variability (PPV) were monitored. Propofol and Fentanyl infusions were used for maintenance of anesthesia. The patients were made prone on bolsters and all the variables were recorded every 5 minutes in supine position and after making prone for 20 minutes, before and after incision, muscle splitting and laminectomy. Results: Comparing the last value of the variables in the supine position with those immediately after making prone, SPI increased by 16.36 units (P = 0.003), followed by gradual reduction over the next 20 minutes. Mean arterial pressure and heart rate increased transiently (Pvalue = 0.028 and 0.025, respectively) without any significant change in PPV. Surgical incision also led to a significant increase in SPI. Conclusion: Prone positioning leads to significant increase in SPI, probably due to increased sympathetic tone.

Diaphragm Function Assessment During Spontaneous Breathing Trial in Patients with Neuromuscular Diseases.

INTRODUCTION: The optimal time to discontinue patients from mechanical ventilation is critical as premature discontinuation as well as delayed weaning can result in complications. The literature on diaphragm function assessment during the weaning process in the intriguing subpopulation of critically ill neuromuscular disease patients is lacking. METHODS: Patients with neuromuscular diseases, on mechanical ventilation for more than 7 days, and who were ready for weaning were studied. During multiple T-piece trials over days, diaphragm function using ultrasound and diaphragm electrical activity (Edi peaks using NAVA catheter) was measured every 30 min till a successful 2 h weaning. RESULTS: A total of 18 patients were screened for eligibility over 5-month period and eight patients fulfilled the inclusion criteria. Sixty-three data points in these 8 subjects were available for analysis. A successful breathing trial was predicted by Edi reduction (1.22 µV for every 30 min increase in weaning duration; 0.69 µV for every day of weaning) and increase in diaphragm excursion (2.81 mm for every 30 min increase in weaning duration; 2.18 mm for every day of weaning). CONCLUSION: The Edi and diaphragm excursion changes can be used as additional objective tools in the decision-making of the weaning trials in neuromuscular disease.

Ultrasonographic evaluation of lung and heart in predicting successful weaning in mechanically ventilated neurosurgical patients.

In critically ill neurosurgical patients, delayed and premature extubation increases the risk of morbidity and mortality. Assessment of critically ill patients before and during spontaneous breathing trial (SBT) is crucial in predicting weaning failure. We explored the trend of changes with integrated lung and cardiac ultrasonography in predicting success of weaning in neurosurgical patients. Lung ultrasound and cardiac ultrasound was performed before and after 30 min and 120 min of SBT. Lung ultrasound score (LUS, range 0-36) was calculated using a predefined method of assessment of six chest regions on either side. The left ventricular function was evaluated by measuring fractional area change. The maximum velocities of mitral inflow E and A waves (E/A), deceleration time of E wave (DTE) and tissue doppler based E' wave at lateral annulus to calculate E/E', were measured to assess left ventricular filling pressure. Twenty seven patients underwent SBT, among these 22 had success and five had failure of SBT. The SBT failure group had higher baseline LUS and progressively higher LUS during SBT compared to the success group, suggesting significant lung de-recruitment. There was significant increase in the LV filling pressure (increase E/A and E/E', decrease in DTE) after 30 and 120 min of SBT in failure group compared to the success group. Point of care lung and cardiac ultrasonography may be useful in detecting cardiopulmonary changes induced by SBT. Higher lung aeration loss and LV filling pressure were observed with SBT failure group.

Clinical Characteristics and Outcomes of Critically Ill Neurological Patients with COVID-19 Infection in Neuro-intensive Care Unit: A Retrospective Study.

BACKGROUND: There are insufficient data about clinical outcomes in critically ill neurological patients with concomitant coronavirus disease (COVID-19). This study describes the clinical characteristics, predictors of mortality, and clinical outcomes in COVID-19-positive neurological patients managed in a dedicated COVID-19 neurointensive care unit (CNICU). METHODS: This single-center, retrospective cohort study was conducted in critically ill neurological and neurosurgical patients with concomitant COVID-19 infection admitted to the CNICU at the National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, from July to November 2020. Patients' demographic, clinical, laboratory, imaging, treatment, and outcome data were retrieved from the manual and electronic medical records. Predictors of mortality and neurological outcome were identified using logistic regression. RESULTS: During the study period, 50 COVID-19-positive neurological patients were admitted to the CNICU. Six patients were excluded from the analysis as they were managed in the CNICU for <24 hours. A poor outcome, defined as death or motor Glasgow Coma Scale <5 at hospital discharge, was observed in 34 of 44 patients (77.27%) with inhospital mortality in 26 of 44 patients (59%). Worst modified sequential organ failure assessment (MSOFA) score, lactate dehydrogenase maximum levels (LDHmax), and lymphocyte count were predictors of inhospital mortality with an odds ratio (OR) of 1.88, 1.01, and 0.87, respectively, whereas worst MSOFA and LDHmax levels were predictors for poor neurological outcome with OR of 1.99 and 1.01, respectively. CONCLUSIONS: Mortality is high in neurological patients with concomitant COVID-19 infection. Elevated inflammatory markers of COVID-19 suggest the role of systemic inflammation on clinical outcomes. Predictors of mortality and poor outcome were higher MSOFA score and elevated LDH levels. Additionally, lymphopenia was associated with mortality. HOW TO CITE THIS ARTICLE: Surve RM, Mishra RK, Malla SR, Kamath S, Chakrabarti DR, Kulanthaivelu K, et al. Clinical Characteristics and Outcomes of Critically Ill Neurological Patients with COVID-19 Infection in Neuro-intensive Care Unit: A Retrospective Study. Indian J Crit Care Med 2021;25(10):1126-1132.

Effect of adjunctive dexmedetomidine on anesthesia and analgesia requirement and recovery characteristics during Bispectral Index-guided anesthesia for cerebello-pontine angle surgeries: A randomized clinical trial.

BACKGROUND AND AIMS: The study was conceived to elucidate the effects of dexmedetomidine as an anesthetic adjunct to propofol (total intravenous anesthesia) on anesthetic dose reduction and anesthesia recovery parameters in cerebello-pontine angle (CPA) surgeries. MATERIAL AND METHODS: This prospective randomized study was conducted on 49 patients (25 with dexmedetomidine, 24 without). After standardized anesthetic induction, anesthesia was maintained using propofol (via target controlled infusion, titrated to maintain BIS between 40 and 60), fentanyl (0.5 µg/kg/hour) and either dexmedetomidine (0.5 µg/kg/hour) or a sham infusion. Neuromuscular blocking agents were excluded to allow cranial nerve EMG monitoring. Adverse hemodynamic events, recovery parameters (time to opening eyes, obeying commands, and extubation) and postoperative sedation score, shivering score, nausea, and vomiting score were recorded. RESULTS: Propofol and fentanyl utilization (as total dose, adjusted for duration of surgery and body weight, and number of extra boluses) was significantly lower in the dexmedetomidine group. There was no difference in any of the recovery parameters between the two groups. Incidence of bradycardia was significantly higher with dexmedetomidine, while no difference was found for hypotension, hypertension, and tachycardia. CONCLUSION: Dexmedetomidine-fentanyl-propofol anesthesia compares favorably with fentanyl-propofol anesthesia during CPA neurosurgical procedures with regard to anesthesia recovery times, but with lower intraoperative opioid and hypnotic utilization rates.

ECG contamination of EEG signals: effect on entropy.

Entropy™ is a proprietary algorithm which uses spectral entropy analysis of electroencephalographic (EEG) signals to produce indices which are used as a measure of depth of hypnosis. We describe a report of electrocardiographic (ECG) contamination of EEG signals leading to fluctuating erroneous Entropy values. An explanation is provided for mechanism behind this observation by describing the spread of ECG signals in head and neck and its influence on EEG/Entropy by correlating the observation with the published Entropy algorithm. While the Entropy algorithm has been well conceived, there are still instances in which it can produce erroneous values. Such erroneous values and their cause may be identified by close scrutiny of the EEG waveform if Entropy values seem out of sync with that expected at given anaesthetic levels.

Endovascular coil detachment causing EMG artefact in BIS: a mechanistic exploration.

Deployment of endovascular coils used in interventional neuroradiology commonly involves electrolytic detachment of the coil from the pusher catheter. This report describes a case of artefactual increase in electromyography (EMG) values of bispectral index (BIS) monitor during coil detachment. An explanation of this event is provided connecting mechanism of coil detachment and derivation of EMG values in a BIS monitor. While rising EMG values are thought to arise from frontalis contraction, they may as well be an unrecognized electrical artefact, especially in context of undistorted electroencephalography waveform.

Prevalence and predictors of preoperative cardiac autonomic dysfunction among elective neurosurgical patients: A prospective observational study.

Background and Aims: The autonomic nervous system (ANS) is cardinal for systemic homeostasis. Autonomic dysfunction is prevalent in as high as 65% of patients presenting for cardiac surgery in the Indian scenario. Pre-existing cardiac autonomic dysfunction (CAD) in surgical patients can accentuate perioperative haemodynamic fluctuations during stressful intraoperative events, predispose to adverse cardiac events, and contribute to morbidity and mortality. The prevalence and predictors of CAD in the elective neurosurgical population are unknown in the Indian scenario. The current study was conducted to bridge this knowledge gap. Methods: In this single-centre prospective observational study conducted at a tertiary care neurosciences centre, among 400 consenting adult patients of either gender, between 18 and 80 years of age, undergoing elective neurosurgery, the preoperative ANS function at the bedside was assessed as the primary outcome measure. The ANS status was evaluated using ANSiscope™-derived indices of heart rate variability. The diagnosis of CAD was made when the ANS index exceeded a threshold of 13.5. Data regarding predictors of CAD were collected from patient records as the secondary outcome measure. Statistical analysis was done using the R software. A P-value of <0.05 was considered statistically significant. Results: The prevalence of preoperative CAD in our study population was 79.7% (319/400 patients). None of the demographic and baseline clinical characteristics we studied predicted CAD in our study. Conclusion: We observed a significant prevalence of preoperative CAD among elective neurosurgical patients. None of the parameters we evaluated predicted CAD in our study.

Transcranial ultrasonographic evaluation of effect of ventriculoperitoneal shunt on intracranial dynamics: A prospective observational study.

BACKGROUND: Transcranial sonographic (TCS) evaluation of optic nerve sheath diameter (ONSD), third ventricular diameter (TVD) and mean flow velocities (Vm) and pulsatility index (PI) of middle cerebral artery (MCA) can provide important insights to the change in intracranial dynamics following ventriculo-peritoneal (VP) shunt surgery. The primary objective of this study was to observe changes in ONSD values following VP shunt at 12 h, compared to pre-VP shunt values. METHODS: After obtaining ethical approval, patients admitted with a diagnosis of hydrocephalus posted for a VP shunt surgery were prospectively enrolled. TCS evaluation was done before induction of anesthesia and 12-hour post-VP shunt surgery. We recorded the values of ONSD, TVD and Vm and PI MCA at both time points. RESULTS: Thirty-four patients (19 male) were evaluated for ONSD and for the improvement of symptoms. Transtemporal window could not be obtained in six patients. At 12 h following VP shunt, bilateral median ONSD values reduced significantly from their pre-VP shunt values [right ONSD- 0.62 (0.59-0.64) to 0.53 (0.5-0.54) mm (p < 0.001); left ONSD- 0.62 (0.59-0.63) to 0.53 (0.5-0.54) mm (p < 0.001)]. Similarly, the median TVD at 12 h post-VP shunt reduced significantly from its pre-VP shunt measurements [0.97 (0.85-1.09) to 0.74 (0.7-0.84) cm]. PI MCA values reduced significantly, while Vm MCA values increased significantly from the pre-VP shunt values. CONCLUSION: VP shunt reduced the ONSD, TVD, PI MCA and increased the Vm MCA after shunt surgery as early as 12hrs.

Role of substance P in cerebral edema and association with an estimated specific gravity of the brain and an outcome prediction in post-traumatic cerebral edema.

Purpose: The study aims to evaluate the role of substance P in cerebral edema and outcomes associated with acute TBI. Method: Patients with acute TBI who presented within 6 h and a CT scan showed predominantly cerebral edema were included in the study. Substance P level was assessed from a serum sample collected within 6 h of trauma. We also evaluated the brain-specific gravity using the Brain View software. Result: A total of 160 (128 male) patients were recruited. The median serum substance P concentration was 167.89 (IQR: 101.09-238.2). Substance P concentration was high in the early hours after trauma (p = 0.001). The median specific gravity of the entire brain was 1.04. Patients with a low Glasgow coma scale (GCS) at admission had a high concentration of the substance P. In the univariate analysis, low GCS, elevated serum concentrations of substance P level, high Rotterdam grade, high cerebral edema grade, a high international normalized ratio value, and high blood sugar levels were associated with poor outcomes at six months. In logistic regression analysis, low GCS at admission, high cerebral edema grade, and elevated blood sugar level were strongly associated with poor outcomes at six months. The area under the receiver operating characteristic curve was 0.884 (0.826-0.941). Conclusion: Serum substance P is strongly associated with the severity of cerebral edema after TBI. However, brain-specific gravity does not directly correlate with posttraumatic cerebral edema severity. Serum substance P does not influence the clinical outcome of traumatic brain injury.

Postoperative delayed neurocognitive recovery: Evaluation of its incidence and correlation with intraoperative cerebral desaturation - A prospective observational study.

BACKGROUND: Delayed neurocognitive recovery (DNR) is commonly seen in patients in the postoperative period. Literature has shown that monitoring cerebral desaturation intraoperatively can predict the development of DNR in elderly patients undergoing surgery in prone position. This prospective observational study was conducted in patients of all ages, with the primary objective to determine the incidence of DNR and its correlation with cerebral oximetry. The secondary objectives were to determine if intraoperative cerebral desaturation influenced the neuropsychometric variables from preoperative to postoperative period. METHODS: This study included 61 patients, aged > 18 years undergoing spinal surgery in prone position. An evening before surgery and at 48 h postoperatively, patients were subjected to neuropsychological examination; Hindi Mental State Examination, Colour Trail Test 1 (CTT 1), CTT 2, Auditory Verbal Learning (AVLT) tests conducted by principal investigator (PI). DNR was defined as a 20% change in any of the test scores from the baseline. rSO2 was recorded bilaterally every 10 min throughout surgery by an independent person. Cerebral desaturation was defined as a 20% drop in rSO2 from the control value. RESULTS: The incidence of DNR was 24.6%. The duration of anesthesia and cerebral desaturation were found to be independently predictive of DNR, with each hour of anesthesia causing a two-fold increase in the chances of development DNR (P = 0.019) and presence of cerebral desaturation causing a 6-fold increase (P = 0.039). CTT 1 and CTT 2 tests had significantly larger increase in test scores in the postoperative period, in patients with cerebral desaturation. CONCLUSION: Duration of anesthesia and cerebral desaturation were factors predictive of the development of DNR in patients undergoing spine surgery in prone position.