A prospective observational study to compare and evaluate delta down, aortic velocity time integral variability, and superior vena cava collapsibility index as predictors of fluid responsiveness in patients with supratentorial brain tumors undergoing elective neurosurgery.

Background: Patients undergoing surgical resection of brain tumors frequently exhibit a spectrum of hemodynamic fluctuations necessitating careful fluid management. This study aimed to evaluate the feasibility of dynamic predictors of fluid responsiveness, such as delta down (DD), aortic velocity time integral variability (VTIAoV), and superior vena cava collapsibility index (SVCCI), in patients undergoing neurosurgery for brain tumors. Methods: In this prospective study, 30 patients scheduled to undergo elective neurosurgery for brain tumor resection were enrolled. Baseline measurements of vitals, anesthetic parameters, and study variables were recorded post-induction. Subsequently, patients received a fluid bolus of 10 mL/kg of colloid over 20 min, and measurements were repeated post-loading. Data were presented as mean ± standard deviation. The normally distributed continuous variables were compared using Student's t-test, with P < 0.05 considered statistically significant. The predictive capability of variables for fluid responsiveness was assessed using Pearson's coefficient analysis (r). Results: Of the 30 patients, 22 were identified as volume responders (R), while eight were non-responders (NR). DD >5 mmHg effectively distinguished between R and NR (P < 0.001), with a good predictive ability (r = 0.759). SVCCI >38% differentiated R from NR (P < 0.001), with excellent predictability (r = 0.994). Similarly, VTIAoV >20% was also a good predictor (P < 0.05; r = 0.746). Conclusion: Our study revealed that most patients undergoing surgical resection of brain tumors exhibited fluid responsiveness. Among the variables assessed, SVCCI >38% emerged as an excellent predictor, followed by VTIAoV >20% and DD >5 mm Hg, for evaluating fluid status in this population.

Role of Multimodal Monitoring in the Management of Massive Blood Transfusion in Pediatric Patients Undergoing Excision of Choroid Plexus Carcinoma - A Case-Based Review of a Novel Perioperative Protocol.

Choroid plexus carcinomas (CPCs) are rare intraventricular lesions encountered in the pediatric population. The dreaded perioperative complication causing high mortality and morbidity in patients undergoing excision of CPC is massive intraoperative hemorrhage, which results in massive blood transfusion, and coagulopathy. Hence, the main crux of perioperative management is to tackle intraoperative hemorrhage and coagulopathy by instituting goal-directed blood transfusion guided by multimodality monitoring. This case series and literature review aims to present our institutional experience wherein the patients had a favorable outcome post-excision of CPC owing to goal-directed blood transfusion protocol guided by multimodality monitoring in the perioperative period.

Periprocedural management of patients presenting for neurointerventional procedures using flow diverters for complex intracranial aneurysms: An anesthetist's perspective - A narrative review.

Complex intracranial aneurysms pose significant challenges in the realm of neurointervention, necessitating meticulous planning and execution. This article highlights the crucial roles played by anesthetists in these procedures, including patient assessment, anesthesia planning, and continuous monitoring and maintaining hemodynamic stability, which are pivotal in optimizing patient safety. Understanding these complex procedures and their complications will aid the anesthetist in delivering optimal care and in foreseeing and managing the potential associated complications. The anesthetist's responsibility extends beyond the procedure itself to postprocedure care, ensuring a smooth transition to the recovery phase. Successful periprocedural anesthetic management in flow diverter interventions for complex intracranial aneurysms hinges on carefully orchestrating these elements. Moreover, effective communication and collaboration with the interventional neuroradiologist and the procedural team are emphasized, as they contribute significantly to procedural success. This article underscores the essential requirement for a multidisciplinary team approach when managing patients undergoing neurointerventions. In this collaborative framework, the expertise of the anesthetist harmoniously complements the skills and knowledge of other team members, contributing to the overall success and safety of these procedures. By providing a high level of care throughout the periprocedural period, anesthetists play a pivotal role in enhancing patient outcomes and minimizing the risks associated with these intricate procedures. In conclusion, the periprocedural anesthetic management of neurointervention using flow diverters for complex intracranial aneurysms is a multifaceted process that requires expertise, communication, and collaboration.

Evaluation of Cerebral Perfusion Pressure, Cerebral Blood Flow, and Cerebral Oxygenation at Different Head of Bed Positions Using Transcranial Doppler and Near-Infrared Spectroscopy in Postoperative Neurosurgical Patients.

OBJECTIVES: Nursing postoperative neurosurgical patients with head of bed (HOB) elevation beyond 30° might be desired at times to prevent pulmonary complications. Due to the paucity of studies determining the effect of HOB beyond 30° on cerebral perfusion pressure (CPP), cerebral blood flow (CBF), and regional cerebral oxygenation (rSO2), this study was designed. METHODS: A total of 40 patients following elective neurosurgery for supratentorial tumors were studied in the neurosurgical intensive care unit three hours following admission. They were assessed for CBF velocities of middle cerebral arteries on either side using transcranial color Doppler (TCCD), rSO2 using near-infrared spectroscopy (NIRS), and mean arterial pressure measured at tragus level at various HOB positions. The estimated cerebral perfusion pressure (CPPe) was calculated from TCCD parameters, and the estimated intracranial pressure (ICPe) was then derived. Their variations at different HOB positions were noted. RESULTS: TCCD parameters such as peak systolic velocity (PSV) and mean flow velocity (MFV) did not significantly vary upon elevating HOB from 0° to 30° but reduced significantly when HOB was further elevated to 60° (p < 0.05). ICPe reduced significantly with a change of HOB positions from 0° to 60° (p < 0.001), and a significant reduction in CPPe was noticed when HOB was elevated to 60° (67.2 ± 10.1 mmHg vs. 74.7 ± 11.2 mmHg at 0°). However, none of these HOB positions affected rSO2 values. CONCLUSION: Postoperative nursing with positions up to 60° HOB can be tried in indicated patients following elective neurosurgery when complemented with CBF velocity and rSO2 monitoring and in whom CPP-guided therapy is not preferred.

Non-opioid versus Opioid Peri-operative Analgesia In Neurosurgery (NOPAIN): Study protocol for a multi-centric randomised controlled trial.

Background and Aims: Many patients suffer from post-operative pain after neurosurgery despite using intra-operative opioids. Opioid side effects are problematic in neurosurgical patients. Hence, non-opioid alternatives for the management of nociception and pain are needed. Previous studies comparing opioids with non-opioids in the neurosurgical population were few, from single centres, of small sample sizes and were equivocal in findings, which prevented change in clinical practice. To overcome these limitations, we are conducting a multi-centre trial with objectives to compare intra-operative rescue opioid requirements and post-operative pain scores (primary objectives), adverse events, quality of recovery from anaesthesia, quality of sleep and patient satisfaction during hospital stay, and persistent post-surgical pain and quality of life at 3 and 6 months (secondary objectives) in patients receiving opioid and non-opioid analgesia for brain tumour surgeries. Methods: This study protocol describes the methodology of a multi-centre randomised controlled trial. Ethics committee approval has been obtained from all five centres, the trial has been registered with the Clinical Trial Registry- India, and insurance has been obtained for this investigator-initiated funded study. In patients undergoing supra-tentorial brain tumour surgery (population), we will compare fentanyl (intervention) 1 µg/kg/h with dexmedetomidine (comparator) 0.5 µg/kg/h administered during surgery with regards to intra-operative rescue opioid requirement and post-operative pain (primary outcomes). Results: We describe the study protocol of the multi-centre trial (protocol version 2, dated 29/01/2022). The first patient was recruited on 19/10/2022, and we will complete recruitment before March 2024. Conclusion: We expect our study to establish dexmedetomidine as an effective non-opioid analgesic vis-à-vis opioids in the neurosurgical population.

Use of near infrared spectroscopy for the prediction of perioperative complications in patients undergoing elective microsurgical resection of cerebral arteriovenous malformations- a prospective observational trial (NIRSCAM trial).

PURPOSE: Cerebral arteriovenous malformations (AVM) represent focal abnormal areas of low resistance circulation which render the peri-nidal neuronal tissue susceptible to ischemia. The post-excision cerebral perfusion surge can result in hyperaemic complications.We hypothesised that Near Infrared Spectroscopy (NIRS)-guided perioperative management can aid in the prediction and prevention of perioperative complications in patients presenting for surgical excision of cerebral AVMs. We also intended to identify a threshold value of regional cerebral oxygen saturation (rScO2) to predict the incidence of perioperative complications. METHODS: This was a prospective observational study involving patients undergoing elective supratentorial AVM resection surgeries. Intraoperative rScO2 and hemodynamic monitoring were done and continued for postoperatively for 12 h. Any drift in rScO2 by > 12% from baseline was managed as per study protocol and perioperative adverse events were recorded and analyzed. Post surgery,for analytical purpose patients were categorized into two groups, Group A - patients without complications and Group B - patients who had complications postoperatively. RESULTS: Twenty-five patients presenting for surgical excision of cerebral AVM were recruited for this study of which 9 patients had postoperative adverse events and were allocated to group B. The ipsilateral mean rScO2 at the time of complication (Pc) was significantly lower in Group B than in group A [62.08 ± 9.33 vs.70.52 ± 7.17; p = 0.04]. The mean ipsilateral rScO2 drift from N2- N5 (i.e., post excision) was significantly higher in Group B than in Group A [12.01 ± 2.63% vs. 4.98 ± 5.7%;p = 0.02]. Mean ipsilateral rScO2 Drift ratio (N5 :N2) was significantly higher in group B as compared to group A [1.32 ± 0.01 vs. 1.01 ± 0.06;p < 0.001]. In the immediate post excision phase, the ipsilateral mean rScO2 was significantly higher in Group B at the post excision time point compared to Group A [ 83.03 ± 6.08 vs. 73.52 ± 7.07;p < 0.01)]. The mean ipsilateral rScO2 drift from N1-N6 (i.e., postoperatively) was significantly higher in Group B as compared to Group A [14.96 ± 0.080% vs. 6.88 ± 4.5% ; p < 0.01]. Similarly, the Mean Ipsilateral rScO2 Drift ratio (N6:N1) was significantly lower in group B as compared to group A [2.17 ± 0.02 vs. 1.05 ± 0.03 ;p < 0.0001]. CONCLUSIONS: In patients undergoing cerebral AVM resection, a post-resection ipsilateral rScO2 increase by > 12% with a drift ratio of > 1.3 could signify cerebral hyperemia. A postoperative ipsilateral rScO2 drift > 14.5% with a drift ratio of 2.1 from the baseline is associated with postoperative complications in our study. Further multi-centric randomized control trials are needed to support our research findings.

Role of multimodal monitoring in the management of patients undergoing complex intracranial bypass procedures - A case series and literature review.

Patients undergoing complex intracranial neurovascular procedures continue to have a high mortality rate. Individualised goal-directed cerebral resuscitation employing multimodality neuromonitoring may impact these patients' treatment and prognosis. Advanced monitoring methods aid in the early identification of secondary brain insults and serve as endpoints for goal-directed therapy in the perioperative period. Unfortunately, there is a paucity of literature exploring the impact of multimodality monitoring and its outcome in these patients. We aim to present this case series wherein the patients had a favourable outcome post-intracranial complex bypass procedure, owing to goal-directed management guided by multimodality monitoring in the perioperative period.

Autologous versus allogeneic blood transfusion: A comparative study of the peri-operative outcomes in a tertiary care hospital in South India amidst the COVID-19 pandemic.

Autologous blood transfusion is known to have advantages over allogeneic transfusion. The COVID-19 pandemic intensified the already existing shortage of allogeneic blood supply. We carried out a study during this period with the aim to elicit the effects of autologous blood collection and transfusion, to compare the peri-operative outcomes of autologous and allogeneic transfusion practices and also to assess the influence of the autologous transfusion programme in the Blood Centre inventory. It was prospective observational comparative study among neurosurgical and vascular surgical patients in a tertiary care centre in South India. 141 patients were allocated into Group I (n = 71) who received autologous transfusion and those who received conventional allogeneic transfusion were clustered as Group II (n = 72) for analysis. We employed Acute Normovolemic Hemodilution (ANH), Pre-deposit Autologous Donation (PAD) and Intra-operative Cell Salvage (ICS) as various modalities for autologous blood collection. In our study, 43 (60.6%) from Group I received exclusive autologous blood transfusion, whereas 28 (39.4%) required additional allogeneic transfusion. No significant difference in hemoglobin, hematocrit, platelet count and INR were observed between the groups post transfusion. Significant difference was observed in the thoracoabdominal aortic aneurysm (TAAA) patients with respect to duration of ICU stay (2.7 ± 1.1 days in Group I and 6.2 ± 0.8 days in Group II; p = 0.002) and re-exploration due to bleeding (16.7% in Group I and 40% in Group II; p = 0.048). Autologous blood transfusion is safe and effective. It can be employed as routine practice and also during any acute shortage or pandemic.

Recent advancements in the practice of neuroanaesthesia and neurocritical care: An update.

The practice of neuroanaesthesia has expanded significantly in recent years to keep up with various challenges posed in the perioperative care of patients for neurosurgical, interventional, neuroradiological, and diagnostic procedures. Technological advancements in neuroscience include the intraoperative use of computed tomography scans and angiograms for vascular neurosurgery, magnetic resonance imaging, neuronavigation, expansion of minimally invasive neurosurgery, neuroendoscopy, stereotaxy, radiosurgery, the performance of increasingly complex procedures, advancements in neurocritical care, etc. Recent advancements in neuroanaesthesia that can meet these challenges include the resurgence of ketamine, opioid-free anaesthesia, total intravenous anaesthesia, techniques to facilitate intraoperative neuromonitoring, awake neurosurgical and spine surgeries, etc. The current review provides an update on the recent advancements in neuroanaesthesia and neurocritical care.

Electrocardiographic changes in patients with raised intracranial pressure from supratentorial brain tumors.

Objectives: A wide variety of electrocardiographic (ECG) changes has been described in the context of neurological catastrophe. There has been diverse and plentiful literature emphasizing the cardiac changes in acute cerebrovascular events and traumatic brain injury. In stark contrast, there is scarce literature on the incidence of cardiac dysfunction caused by raised intracranial pressure (ICP) resulting from brain tumors. The study aimed to observe the ECG changes concurrent with intracranial hypertension resulting from supratentorial brain tumors. Materials and Methods: This is a pre-specified subgroup analysis of a prospective and observational study on cardiac function in patients presenting for neurosurgery. Data of 100 consecutive patients of either sex between 18 and 60 years who presented with primary supratentorial brain tumors were analyzed. The patients were divided into two groups: Group 1 consisted of patients without clinical and radiological features of raised ICP and Group 2 consisted of patients with clinical and radiological features of raised ICP. A 12-lead ECG was obtained for every patient on the day before the neurosurgical procedure as part of the pre-anesthetic assessment. The cardiologist and the neuroanesthetist independently examined the ECG, and it was then classified and coded as per the standardized Minnesota code. Statistical analysis was performed with IBM SPSS (release 22.0; IBM Corp., Armonk, NY, USA). The normality of the distribution of continuous variables was tested using the Shapiro-Wilk test. Normally distributed variables were expressed as Mean ± SD. All nominal or categorical variables are described as frequencies and percentages. Categorical variables were compared using the Chi-square test or the Fisher's exact test. The normally distributed continuous variables were compared using Student's t-test. "P < 0.05" was considered statistically significant. Results: About 6% in Group 1 and 32% in Group 2 had abnormal ECG. This was significantly different in Group 2 compared to Group 1 (P < 0.05). No patients in Group 1 had sinus bradycardia, whereas it was observed in 12% of the patients in Group 2 (P = 0.02). ST-segment depression was found in 12% of patients in Group 2, whereas none had it in Group 1 (P = 0.02). ST-segment elevation was noticed in 16 % in Group 2 and 2% in Group 1 (P = 0.01). T-wave abnormalities were found in 16% compared to 4% in Group 1 (P = 0.03). Conclusion: In patients with supratentorial tumors, we observed that those with raised ICP had a higher incidence of ECG changes than those with normal ICP. In addition, repolarization abnormalities and arrhythmias were significantly higher in patients with raised ICP.

Evaluation of markers of cerebral oxygenation and metabolism in patients undergoing clipping of cerebral aneurysm under total intravenous anesthesia versus inhalational anesthesia: A prospective randomized trial (COM-IVIN trial).

INTRODUCTION: Anesthetic goals in patients undergoing clipping of cerebral aneurysm include maintenance of cerebral blood flow, oxygenation, and metabolism to avoid cerebral ischemia and maintenance of hemodynamic stability. We intend to study the influence of anesthetic agents on the outcome of aneurysmal subarachnoid hemorrhage (SAH). MATERIALS AND METHODS: This is a prospective, randomized, parallel, single-center pilot trial approved by the Institutional Ethics Committee and is prospectively registered with the Clinical Trial Registry of India. Patients with aneurysmal SAH (aSAH) admitted to our institution for surgical clipping, fulfilling the trial inclusion criteria, will be randomized in a 1:1 allocation ratio utilizing a computerized random allocation sequence to receive either total intravenous anesthesia (n = 25) or inhalational anesthesia (n = 25). Our primary objective is to study the effects of these anesthetic techniques on cerebral oxygenation and metabolism in patients with aSAH. Our secondary objective is to evaluate the impact of these anesthetic techniques on the incidence of delayed cerebral ischemia and long-term patient outcomes in patients with aSAH. The Modified Rankin Score and Glasgow Outcome Scale (GOS) at discharge and 3 months following hospital discharge will be evaluated. An observer blinded to the study intervention will assess the outcome measures. DISCUSSION: This study will provide more insight as to which is the ideal anesthetic agent that offers a better neurophysiological profile regarding intraoperative cerebral oxygenation and metabolism, thereby contributing to better postoperative outcomes in aSAH patients.

A prospective-randomized placebo-controlled trial comparing the effects of nebulized dexmedetomidine v/s dexmedetomidine-lignocaine mixture on intraoperative hemodynamics and surgical field quality in patients undergoing endoscopic transnasal transsphenoidal pituitary tumor surgery.

Background: During transnasal transsphenoidal pituitary surgery (TNTSS), the primary objective is to maintain stable hemodynamics while ensuring ideal surgical conditions. This study aimed to investigate the effect of nebulized dexmedetomidine on hemodynamic parameters and the quality of the surgical field during TNTSS. Methods: Seventy-five patients scheduled for TNTSS were randomized into three groups of 25 each and received preoperative nebulization with 5 mL of nebulizing fluid consisting of 1.5 µg/kg of dexmedetomidine with saline in dexmedetomidine (D) group; 1.5 µg/kg of dexmedetomidine with 2% lignocaine in dexmedetomidine-lignocaine (DL) group and normal saline in the control (S) group. Heart rate (HR), mean blood pressure, Formmers score, anesthetic requirement, and emergence were evaluated for each group. Results: Group S had significantly higher HR and mean arterial pressure than the other two groups across various time points during surgery (P < 0.01). The total requirements for fentanyl, propofol, sevoflurane, and labetalol and the incidence of delayed emergence were significantly higher in the S group compared to the other two groups (P < 0.01). The D and DL groups exhibited significantly better surgical field conditions than the S group. In all the parameters assessed, patients in the D group outperformed those in the DL group. Conclusion: The administration of nebulized dexmedetomidine, both alone and in combination with lignocaine, resulted in stable hemodynamics, favorable operative conditions, reduced anesthetic requirement, and facilitated prompt emergence during TNTSS. Nebulized dexmedetomidine proved superior to its combination with lignocaine across all evaluated parameters.

Near-Infrared Spectroscopy-Guided Hyperventilation for Transient Intracranial Pressure Control during Anesthesia Induction in a Patient with Impending Uncal Herniation.

Near-infrared spectroscopy (NIRS) is known to determine the adequacy of regional cerebral oxygen supply. NIRS values during anesthetic induction depends upon various factors such as anesthetic agents, inspired oxygen fraction, blood carbon dioxide levels and systemic blood pressure. Also high intracranial pressure (ICP) can lead to reduced NIRS values, secondary to increased cerebral vascular resistance induced decrease in cerebral blood flow. However optimal hyperventilation instituted as a bridge to definitive ICP management is difficult to ascertain as hypocapnia due to poorly titrated hyperventilation can potentially worsen ICP. Here we describe a novel application of NIRS-guided hyperventilation during anesthesia induction in a brain tumor patient with raised ICP features and impending uncal herniation as suggested by computed tomography (CT) scan, with ipsilateral baseline reduced NIRS values. These ipsilateral NIRS values further reduced significantly during anesthesia induction even before profound bradycardia occurred, which promptly improved to baseline following hyperventilation.

At the Eye of the Hurricane! Perioperative Management of an Unoptimized Metastatic Pheochromocytoma Presenting for Emergency Neurosurgery.

Metastatic pheochromocytoma (PCC) is a rare entity arising from extra-adrenal tissue. We report the perioperative management of a young woman presenting with metastatic PCC to the vertebral body resulting in vertebral collapse and spinal cord compression necessitating emergency surgery. There are no reports of anesthetic management of a patient with unoptimized metastatic PCC presenting for emergency neurosurgery under general anesthesia. Our anesthetic goals were to maintain a deep anesthetic plane with stable hemodynamics, facilitate intraoperative neuromonitoring, manage catecholamine surges during anesthetic induction, tumor resection, and manage perioperative massive blood loss. The successful perioperative management of metastatic PCC has become possible with the vast armamentarium of anesthetic drugs and intraoperative advanced monitoring techniques. In addition, our role in understanding the pathophysiology and course of the disease is essential to ensure low morbidity and mortality of such cases in their most vulnerable perioperative period.

Anesthetic Management of a Patient With Arterial Tortuosity Syndrome Undergoing Cerebral Revascularization Surgery-A Case Report.

Arterial tortuosity syndrome is a rare hereditary autosomal recessive connective tissue disorder characterized by elongation and tortuosity of the large- and medium-sized arteries. We present the case of a 13-year old child with arterial tortuosity syndrome who underwent occipital encephaloduroarteriomyosynangiosis for posterior circulation insufficiency. The constellation of clinical features in our patient portended significant anesthetic concerns, including difficult airway due to craniofacial abnormalities, risk of stroke, and myocardial infarction due to intracerebral and coronary arterial tortuosity and stenosis. The pertinent anesthetic implications are summarized, and we describe the anesthetic technique and use of multimodal neuromonitoring relevant for the case.

A Comparative Study to Evaluate the Efficacy of Virtual Versus Direct Airway Assessment in the Preoperative Period in Patients Presenting for Neurosurgery: A Quest for Safer Preoperative Practice in Neuroanesthesia in the Backdrop of the COVID-19 Pandemic!

Objectives Neurosurgical patients with cervical spine pathologies, craniofacial and craniovertebral junction anomalies, recurrent cervical spine, and posterior fossa surgeries frequently present with an airway that is anticipated to be difficult. Although the routine physical evaluation is nonaerosol-generating, Mallampati scoring, mouth opening, and assessment of lower cranial nerve function could potentially generate aerosols, imposing a greater risk of acquiring severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection. Moreover, airway evaluation requires the patient to remove the mask, thereby posing a greater risk to the assessing anesthesiologist. Thus, we designed this study to evaluate the efficacy of virtual airway assessment (VAA) done via telemedicine in comparison to direct airway assessment (DAA), and assess the feasibility of VAA as a part of the preanesthetic evaluation (PAE) of patients presenting for neurosurgery in the backdrop of the COVID-19 pandemic. Materials and Methods A total of 55 patients presenting for elective neurosurgical procedures were recruited in this prospective, observational study. The preoperative assessment of the airway was first done by a remote anesthetist via an encrypted video call, using a smartphone which served the purpose of telemedicine equipment, followed by a direct assessment by the attending anesthetist. The following parameters were assessed: mouth opening (MO), presence of any anomalies of tongue and palate, Mallampati classification (MPC) grading, thyromental distance (TMD), upper lip bite test (ULBT), neck movements, and Look-Evaluate-Mallampati-Obstruction-Neck mobility (LEMON) scoring system. Statistical Analysis Demographic parameters were expressed as mean ± SD. Agreement between the values obtained by VAA and DAA parameters were analyzed with the Kappa test. Results We observed a "perfect agreement" between the DAA and VAA with regard to MO. Assessment of ULBT, neck movements, and the LEMON score had an overall "almost perfect agreement" between the DAA and VAA. We also observed a "substantial agreement" between VAA and DAA during the assessment of MPC grading and TMD. Conclusion Our study shows that PAE and VAA via telemedicine can reliably be used as an alternative to direct physical preanesthetic consultation in the COVID-19 scenario. This could reduce unnecessary exposure of anesthesiologists to potential asymptomatic COVID-positive patients, thereby protecting the available skilled workforce, without any significant compromise to patient care.