Preoperative assessment of optic nerve sheath diameter and heart rate variability to predict intraoperative brain condition in patients with supratentorial tumors: a prospective observational study.

Brain relaxation is an important requirement in intracranial neurosurgical procedures and optimal brain relaxation improves the operating conditions. Optic nerve sheath diameter (ONSD) is a non-invasive bedside surrogate marker of intracranial pressure (ICP) status. Elevated ICP is often associated with marked autonomic dysfunction. There is no standard measure to predict intraoperative brain condition non-invasively, considering both anatomical displacement and physiological effects due to raised ICP and brain oedema. This study was aimed to determine the usefulness of heart rate variability (HRV) parameters and ONSD preoperatively in predicting intraoperative brain relaxation in patients with supratentorial tumors undergoing surgery.This prospective observational study was conducted in a tertiary care centre. 58 patients with supratentorial brain tumors undergoing elective surgery were studied. Preoperative clinical presentation, computed tomography (CT) findings, ONSD and HRV parameters were assessed in determining intraoperative brain condition. Intraoperative hemodynamic parameters and brain relaxation score after craniotomy were studied. There was significant difference in CT grade, ONSD and HRV parameters in patients between lax and tight brain. A receiver operating curve was constructed to determine the cut off to predict intraoperative brain bulge. A CT grade more than 2, ONSD of greater than 0.63 cms and ratio of low frequency to high ratio (LF/HF) of more than 1.8 were good predictors of brain bulge. The changes in ONSD and HRV parameters, with the CT findings can be used as surrogate markers of increased ICP to help predict intraoperative brain condition.

Neurogenic stunned myocardium resulting from surgical brainstem handling during resection of paediatric recurrent medulloblastoma-a possible brain heart interaction.

BACKGROUND: Neurogenic stunned myocardium (NSM) is characterised by an acute onset cardiac dysfunction following an acute neurological insult which mimics acute coronary syndrome. CASE DETAILS: A 12-year-old male child was admitted to the neuro-intensive care unit (NICU) following midline suboccipital craniotomy and resection of recurrent medulloblastoma. Postoperatively, in NICU, he developed tachycardia and hypotension, which was unresponsive to fluid challenge requiring norepinephrine infusion. Intraoperatively, during tumour resection from the dorsal medulla, episodes of hypertension and bradycardia were observed. Intraoperative blood loss was adequately managed with a stable hemodynamic profile without postoperative anaemia. An electrocardiogram showed sinus tachycardia with T wave inversion, and blood investigation revealed elevated cardiac troponin T levels. Point of care ultrasound (POCUS) of heart and lung showed features of NSM. Infusion dobutamine was added to achieve a target mean arterial pressure of 65 mm Hg with concomitant furosemide infusion and fluid restriction. Daily POCUS assessment of cardiac contractility and volume status was done. The patient was weaned from vasoactive drugs and ventilator following improvement of cardiac function and was discharged from NICU after 17 days. CONCLUSION: NSM results from the excessive release of catecholamines following stimulation of trigger zones in the brain. To date, a handful of cases of pediatric NSM following primary brain tumour are reported where hydrocephalus resulted in trigger zone activation. In this presented case, direct brain stem stimulation during tumour resection might have triggered NSM. Irrespective of the cause, timely diagnosis and execution of supportive management in our patient resulted in a positive outcome.

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.

Intracranial Pressure Monitoring Location: A Pilot Study on the Validation of Subdural Site with the Intraventricular Site.

Introduction Knowledge of preoperative and intraoperative intracranial pressure (ICP) enables the neuroanesthesiologist to optimize cerebral perfusion pressure. However, ICP is rarely monitored during the intraoperative period. In this report, subdural site ICP measurement is validated with intraventricular ICP measurement, and the feasibility of subdural ICP monitoring during the intraoperative period is discussed. Materials and Methods In this prospective pilot study, ICP measurement at the subdural site was achieved with an intravenous cannula and the ventricular site with a ventricular cannula. Both were transduced using a fluid-filled pressure transducer and connected to the monitor for display of the number and the waveforms. Monitoring of intraoperative ICP using both the techniques was done in all patients recruited into the study. The correlation between the two modalities of measurement was studied by the Spearman correlation test and their limits of agreement were studied using the Bland-Altman plot. A case series describing the perioperative management based on the subdural ICP values are also described. Results Subdural ICP showed a strong correlation with intraventricular ICP ( r s = 0.93, p = 0.01). Agreement analysis using the Bland-Altman plot showed that the mean difference of ICP between the modalities was 1.44 mm Hg (95% confidence interval, -0.6 to 3.49, p = 0.122). Discussion This study validates the ICP values measured at the subdural site with the intraventricular site. Subdural site ICP monitoring can be achieved rapidly with readily available systems and helps in making intraoperative clinical decisions. Conclusion Cannula-based subdural ICP is a satisfactory alternative to intraventricular ICP monitoring in the intraoperative period.

Fatal multiorgan dysfunction following repeated iodinated radiocontrast injection in a patient receiving low-dose oral methotrexate -a case report.

BACKGROUND: Methotrexate is an antimetabolite drug that blocks dihydrofolate reductase and impairs cellular DNA synthesis. Administration of intravenous iodinated radiocontrast agents can cause life-threatening toxicity in patients receiving methotrexate. CASE: A 60-year-old female patient with rheumatoid arthritis underwent a craniotomy and clipping of a distal anterior cerebral artery aneurysm. The patient had been on low-dose oral methotrexate for the previous 5 years, which was discontinued two days before surgery. The patient received the first intravenous contrast agent injection (iohexol) during diagnostic cerebral angiography one day prior to surgery (50 ml) and the second contrast dose on the first postoperative day (60 ml). The patient developed severe methotrexate toxicity, leading to fatal multiorgan failure and death following repeated contrast imaging with intravenous iohexol. CONCLUSIONS: Even though low-dose oral methotrexate has minor adverse effects, life-threatening toxicity can be precipitated in the presence of iodinated contrast agents.

Role of Nimodipine and Milrinone in Delayed Cerebral Ischemia.

OBJECTIVE: The role of nimodipine and milrinone in the management of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH) was studied using clinical and TCD (transcranial Doppler) parameters. METHODS: In this prospective observational study, patients with DCI after aneurysmal SAH presenting between November 2020 and June 2021 who were treated by either intra-arterial nimodipine (IAN) or intravenous milrinone (IVM) were included after excluding patients in whom both IAN and IVM had been given or mechanical angioplasty was performed. Twelve-hourly TCD was performed during the course of the therapy. Clinical improvement and the development of new brain infarcts were also assessed. A P value <0.05 was considered statistically significant. RESULTS: Thirty-four patients fulfilled the inclusion criteria (IVM, 13/34 [38%]; IAN, 21/34 [62%]); patients in the IVM group (vs. IAN group) had poorer median Glasgow Coma Scale score (12 vs. 13), poorer motor response (