Evaluation and correlation of nociceptive response index and spectral entropy indices as monitors of nociception in anesthetized patients.

Objectives: During anesthesia, the response to these stimuli depends on the balance between nociception and antinociception. Recently, various monitoring systems based on the variables derived from electroencephalography, plethysmography, autonomic tone, reflex pathways, and composite algorithms have been introduced for monitoring nociception. The main aim of our study was to evaluate and correlate the physiological variables which reflect the autonomic nervous system response to nociception, such as heart rate (HR), systolic blood pressure (SBP), perfusion index (PI), and nociceptive response index (NRI), with the spectral entropy indices response entropy (RE) and RE-state entropy (SE), which reflects electromyographic (EMG) activation as a response to pain. Materials and Methods: This is a retrospective analysis of the data from a prospective study on the hypnotic and analgesic effects and the recovery profile of sevoflurane-based general anesthesia. Eighty-six patients undergoing single-agent sevoflurane anesthesia were recruited in the study. The study parameters, HR, SBP, SE, RE, RE-SE, PI, and NRI, were recorded at predefined time points before and after a standardized noxious stimulus. Correlation between the variables was carried out by applying the Pearson correlation equation for normal and the Spearman correlation equation for non-normally distributed data. Receiver operating characteristic (ROC) graphs were plotted, and the area under the curve was calculated to assess the diagnostic accuracy of post-stimulus NRI in detecting pain which was defined as RE-SE >10. Results: There was a significant increase in the SBP, HR, NRI, RE, SE, and RE-SE and a considerable decrease in PI values during the post-noxious period compared to the pre-noxious period. There was no correlation between the absolute values of NRI and entropy indices at T2. However, among the reaction values, there was a weak correlation between the reaction values of NRI and RE (r = 0.30; P = 0.05). The area under the ROC curve for NRI to detect pain as defined by RE-SE >10 was 0.56. Conclusion: During sevoflurane anesthesia, the application of noxious stimulus causes significant changes in variables reflecting sympathetic response and EMG activity. However, NRI failed to detect nociception, and there was only a weak correlation between the reaction values of NRI and RE-SE.

Anesthesia for same day neurosurgery with updates on awake craniotomy and awake spine surgery.

PURPOSE OF REVIEW: This article delves into recent advances in same-day neurosurgery (SDNS), specifically concerning indications, perioperative protocol, safety, and outcomes. Additionally, it explores the recent updates on awake craniotomy and awake spine surgery. RECENT FINDINGS: There is an evolving body of literature on studies about SDNS that reaffirm its safety and feasibility. awake craniotomy is associated with lesser neurological deficits and better survival benefits in patients with lesions in eloquent areas. Monitored anesthesia care, compared with the asleep-awake-asleep technique, is associated with lower failure rates, shorter procedure time, and shorter length of stay. However, the incidence of intraoperative seizures is lower with the asleep-awake-asleep technique. Propofol-based and dexmedetomidine-based anesthesia are similar with regard to procedure duration, intraoperative adverse events, and patient satisfaction; however, surgeon satisfaction is higher with dexmedetomidine-based anesthesia. In spine surgery, regional anesthesia when compared with general anesthesia, is associated with less intraoperative blood loss and a lower incidence of postoperative nausea and vomiting after 24 h. In addition, implementing an enhanced multimodal analgesia protocol improved disability scores and reduced the likelihood of postoperative complications. SUMMARY: SDNS offers promising prospects for patients and healthcare providers alike, with the potential to provide well tolerated, efficient, and cost-effective neurosurgical care in carefully selected cases.

A Perfusion Index-Based Evaluation and Comparison of Peripheral Perfusion in Sevoflurane and Isoflurane Anaesthesia: A Prospective Randomised Controlled Trial.

OBJECTIVE: Perfusion index has shown to be helpful in the operative and critical care settings to monitor peripheral tissue perfusion. Randomised controlled trials quantifying different agents' vasodilatory properties using perfusion index has been limited. Therefore, we undertook this study to compare the vasodilatory effects of isoflurane and sevoflurane using perfusion index. METHODS: This is a pre-specified sub-analysis of a prospective randomised controlled trial on the effects of inhalational agents at equipotent concentration. We randomly allocated patients scheduled for lumbar spine surgery to either isoflurane or sevoflurane groups. We recorded values of perfusion index at age-corrected 1 Minimum Alveolar Concentration (MAC) concentration at baseline, pre- and post-application of a noxious stimulus. The primary outcome of interest was the measure of vasomotor tone with perfusion index, and the secondary outcomes which were analysed were mean arterial pressure and heart rate. RESULTS: At age-corrected 1.0 MAC, there was no significant difference in the pre-stimulus haemodynamic variables and perfusion index between both groups. During the post-stimulus period, there was a significant increase in heart rate in the isoflurane group compared to the sevoflurane group, with no significant difference in the mean arterial pressure values between both groups. Though the perfusion index decreased during the post-stimulus period in both groups, there was no statistically significant difference between the 2 groups (P = .526, repeated-measures analysis of variance). CONCLUSION: In a steady state of age-corrected 1.0 MAC, isoflurane and sevoflurane had a similar perfusion index before and after a standardised nociceptive stimulus, which suggests that both of these agents have similar effect on peripheral perfusion and vasomotor tone.

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.

An Entropy-Based Prospective Randomized Controlled Trial to Evaluate the Analgesic and Hypnotic Effects of Equipotent Doses of Sevoflurane and Isoflurane in Patients Presenting for Spine Surgeries.

Objectives Minimal alveolar concentration (MAC) of anesthetic agents has been considered a suitable measure of the potency of inhalational anesthetics. Furthermore, it is assumed that equi-MAC concentrations of different anesthetic agents have a similar potency in suppressing responses to painful stimuli. Isoflurane and sevoflurane are two commonly used volatile anesthetic agents in spine surgeries. Therefore, these agents' hypnotic and analgesic potencies should be distinguished and comprehended for the optimal administration of anesthesia. Consequently, we undertook this study to compare the analgesic and hypnotic potencies between these agents at equi-MAC concentrations, using the entropy monitor. Materials and Methods Forty patients undergoing lumbar spine surgery were randomly assigned to two groups receiving either isoflurane ( n = 20) or sevoflurane ( n = 20). After induction, maintenance of anesthesia was done with age-corrected 1.0 MAC of either isoflurane or sevoflurane. A standardized noxious stimulus was provided to all the patients after achieving a steady state of 1.0 MAC. The state entropy (SE), response entropy (RE), and RE-SE were recorded at baseline, prestimulus, and poststimulus time points in both groups. Statistical Analyses Data are presented as frequency and percentages for categorical variables and mean ± standard deviation for continuous variables. The comparison of categorical variables between the two groups was made using the Fisher's exact test, and the Student's t -test was used for continuous variables. A p -value of < 0.05 was considered to be statistically significant. Results At age-corrected 1.0 MAC, there was no significant difference in the SE, RE, and RE-SE in both the groups at any time point. Conclusion Our study shows that during a steady state of age-corrected 1.0 MAC single-agent anesthesia, sevoflurane and isoflurane have comparable analgesic and hypnotic potencies as measured by entropy indices when a standardized nociceptive stimulus is provided.

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.

Anesthetic Management of Hashimoto's Encephalopathy Presenting for Spine Surgery.

Hashimoto's encephalopathy (HE) is a rare neuroendocrine disorder, and there are no reports regarding anesthetic implications in a patient diagnosed with HE. These patients can have a plethora of systemic manifestations involving cardiovascular, respiratory, renal, gastrointestinal, hematologic, and central nervous systems. Once diagnosed, meticulous preoperative assessment is essential to rule out systemic involvement and to reduce the perioperative morbidity. Perioperative steroid therapy, neuromonitoring in the perioperative period, opioid free analgesia, and avoidance of nephrotoxic drugs are of paramount importance in the management of such patients. Awareness of the clinical condition and extreme vigilance can detect relapses in the perioperative period. Thus, a meticulous preoperative assessment, balanced anesthesia, perioperative neuromonitoring, and steroid therapy are essential to reduce the perioperative morbidity.

Multimodal monitoring to aid detection and management of intraoperative seizures: a case report.

One of the primary goals in Neuroanesthesia is to preserve cerebral oxygenation and protect the brain from secondary injuries. Seizures have severe implications in the intraoperative period, as it can instigate an increase in cerebral metabolism and oxygen demand, thus causing cerebral hypoxia. Detection of intraoperative seizures is imperative in neurosurgical cases as the ramifications of intracranial hypertension and cerebral hypoxia caused by it can affect patient prognosis and perioperative outcomes. We report a case of detecting intraoperative seizures with the aid of patient state index and near infrared spectroscopy. Multi-modality monitoring aided in the management of a time-sensitive complication, which could otherwise have possibly led to secondary brain insult.

Role of Multimodal Cerebral Oximetry Monitoring in the Anesthetic Management of a Patient With High-Grade Intracranial Arteriovenous Malformation: A Case Report.

Near-infrared spectroscopy (NIRS) is a noninvasive monitor of regional brain tissue oxygenation, and jugular venous oximetry (SjvO2) is a monitor of global cerebral oxygenation. We report the role of intraoperative multimodal monitoring of cerebral oxygenation in the anesthetic management of a patient with grade III intracranial arteriovenous malformation (AVM) presenting for surgical excision. Real-time monitoring of cerebral oxygenation is of much relevance in high-grade AVMs where anesthetic management is focused on neuroprotection and prevention of cerebral hypoxia. Besides, it also helps in prediction, early detection, and judicious management of perioperative complications, which are commonly encountered in high-grade AVMs.

Finding the Calm in the Chaos: An Institutional Protocol for Anesthetic Management of a Patient for Neurosurgery during Coronavirus Disease 2019 Pandemic.

"Coronavirus disease 2019" (COVID-19) transmitted by a novel coronavirus via contact or droplet spread is a highly infectious disease, the containment of which requires vigilance and stringent infection control policies. In the backdrop of hospitals becoming hot zones and an increasing number of health care workers contracting the disease, it is crucial to formulate an approach while administering anesthesia during the testing times of COVID-19 pandemic. In this background, this comprehensive article deals with the perioperative management during this pandemic and includes risk stratification based on an innovative simple scoring system, rationale use of personal protective equipments, and infection prevention protocols. The document of updated literature, though not intended to replace any guidelines, is aimed at providing protocol to health care workers to protect themselves while providing the best care in this pandemic.

A Case of Transposition of Great Arteries with Ventricular Septal Defect and Mesocardia Presenting for Neurosurgery.

Congenitally corrected transposition of great arteries (CC-TGAs) associated with a ventricular septal defect (VSD) presents with cyanotic spells and systemic complications such as brain abscess. In mesocardia, the heart lies in the midline with no apex seen on the left side. We report the anesthetic management of a child with CC-TGA, VSD, and mesocardia presenting with parietal brain abscess for neurosurgery. The significant anesthetic challenges include maintenance of peripheral vascular resistance lower than systemic vascular resistance, prevention of air embolism and paradoxical embolism, avoidance of hyperviscosity in addition to avoiding any rise in intracranial pressure, and maintenance of cerebral perfusion pressure.

Anaesthetic Challenges in a Rare Syndrome: Perioperative Management of a Patient with POEMS Syndrome Who Underwent Umbilical Hernioplasty.

Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome also known as 'Crow Fukase syndrome' is a rare paraneoplastic disorder, first described by Crow and Fukase with distinctive features of polyradiculoneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes. There is a paucity of literature about anaesthetic management of patients with POEMS syndrome with isolated case reports of surgery under general anaesthesia and central neuraxial blockade. We present here the anaesthetic management of a patient with POEMS syndrome posted for umbilical hernia repair, which was successfully managed with a transverse abdominis plane (TAP) block.

Novel application of near-infrared spectroscopy in detecting iatrogenic vasospasm during interventional neuroradiological procedures.

One of the complications of carotid artery stenting (CAS) is iatrogenic vasospasm caused by mechanical irritation of the blood vessel lumen by a guidewire, catheter, stent retriever, or distal protection devices. Although often self-limiting, the mechanical vasospasm can cause reduction in the cerebral blood flow and result in catastrophic ischemia, especially when undetected and persistent. Real-time cerebral oximetry with near-infrared spectroscopy (NIRS) could detect episodes of cerebral hypoxemia due to vasospasm and facilitate intervention for prevention of hypoxic brain injury during neuro-intervention procedures such as CAS. We present a case scenario where NIRS detected iatrogenic vasospasm even before the conventional tests could identify the event during CAS.

A Mysterious Case of Spontaneous Cervical Epidural Hematoma and Bilateral Primary Spontaneous Pneumothorax Caused by a Rare Etiology.

Spontaneous spinal epidural hematoma (SSEH) is a rare disorder that can present as an acute onset of pain and radicular symptoms that mimic disc herniation. Primary spontaneous pneumothorax (PSP) can be defined as the presence of air in the pleural space without apparent underlying lung disease or trauma. We describe a rare case of SSEH in the cervical spine (C5-7) presenting with a novel association, a bilateral PSP, which has never been documented before. Both SSEH and spontaneous pneumothorax, though rare, can be associated with vasculopathy and our patient had signs of vasculopathy of intracranial vessels and pulmonary vasculature. Vasculopathy also needs to be considered while evaluating a case of PSP without emphysema-like changes (ELC) and if diagnosed as the cause, pleurodesis could be considered as a part of the management to avoid the sequel of recurrent pneumothorax and prolonged ICU stay in this subset of patients. HOW TO CITE THIS ARTICLE: Thakkar K, Ajayan N, Unnikrishnan P, Sethuraman M, Hrishi AP. A Mysterious Case of Spontaneous Cervical Epidural Hematoma and Bilateral Primary Spontaneous Pneumothorax Caused by a Rare Etiology. Indian Journal of Critical Care Medicine, January 2019;23(1):51-53.

A Mysterious Case of Spontaneous Cervical Epidural Hematoma and Bilateral Primary Spontaneous Pneumothorax caused by a Rare Etiology.

Spontaneous spinal epidural hematoma (SSEH) is a rare disorder that can present as an acute onset of pain and radicular symptoms that mimic disk herniation. Primary spontaneous pneumothorax (PSP) can be defined as presence of air in the pleural space without apparent underlying lung disease or trauma. We describe a rare case of SSEH in cervical spine (C5-7) presenting with a novel association, a bilateral PSP, which has never been documented before. Both SSEH and spontaneous pneumothorax, though rare, can be associated with vasculopathy and our patient had signs of vasculopathy of intracranial vessels and pulmonary vasculature. Vasculopathy also needs to be considered while evaluating a case of PSP without emphysema-like changes (ELCs) and if diagnosed as the cause, pleurodesis could be considered as a part of the management to avoid the sequel of recurrent pneumothorax and prolonged ICU stay in this subset of patients. How to cite this article Thakkar K, Ajayan N, et al. A Mysterious Case of Spontaneous Cervical Epidural Hematoma and Bilateral Primary Spontaneous Pneumothorax caused by a Rare Etiology. Indian J Crit Care Med 2019;23(4):186-187.