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.

Paving the way to environment-friendly greener anesthesia.

Health-care settings have an important responsibility toward environmental health and safety. The operating room is a major source of environmental pollution within a hospital. Inhalational agents and nitrous oxide are the commonly used gases during general anesthesia for surgeries, especially in the developing world. These greenhouse gases contribute adversely to the environmental health both inside the operating room and in the outside atmosphere. Impact of these anesthetic agents depends on the total consumption, characteristics of individual agents, and gas flows, with higher levels increasing the environmental adverse effects. The inimical impact of nitrous oxide is higher due to its longer atmospheric half-life and potential for destruction of the ozone layer. Anesthesiologist of today has a choice in the selection of anesthetic agents. Prudent decisions will help in mitigating environmental pollution and contributing positively to a greener planet. Therefore, a shift from inhalational to intravenous-based technique will reduce the carbon footprint of anesthetic agents and their impact on global climate. Propofol forms the mainstay of intravenous anesthesia technique and is a proven drug for anesthetic induction and maintenance. Anesthesiologists should appreciate growing concerns about the role of inhalational anesthetics on the environment and join the cause of environmental responsibility. In this narrative review, we revisit the pharmacological and pharmacokinetic considerations, clinical uses, and discuss the merits of propofol-based intravenous anesthesia over inhalational anesthesia in terms of environmental effects. Increased awareness about the environmental impact and adoption of newer, versatile, and user-friendly modalities of intravenous anesthesia administration will pave the way for greener anesthesia practice.

Incidence, risk factors and impact of anemia after elective neurosurgery: A retrospective cohort study.

Objectives: Anemia after surgery is common and is associated with adverse clinical outcomes. Understanding the incidence and risk factors for postoperative anemia is important to reduce anemia-related complications and blood transfusion. There is lack of data regarding postoperative anemia and its contributing factors in neurosurgery. This study evaluates the incidence and risk factors of postoperative anemia, and its impact on clinical outcomes. Methods: This was a single centre, retrospective study of patients who underwent elective neurosurgery over seven months. Data regarding age, gender, body mass index, American Society of Anesthesiologists (ASA) physical status, diagnosis, surgery, preoperative hemoglobin, surgery duration, intraoperative blood loss and red blood cell (RBC) transfusion, dose of tranexamic acid, intraoperative fluid balance, years of surgeon's experience, postoperative hemoglobin, postoperative RBC transfusion, Glasgow Coma Scale (GCS) score at hospital discharge, and duration of postoperative intensive care unit and hospital stay were collected. Logistic regression was used to identify predictors of postoperative anemia. Results: The incidence of postoperative anemia was 11.3% (116/1025). On univariate analysis; age, preoperative hemoglobin, surgery duration, gender, ASA grade, surgery type, and surgeon's experience were associated with postoperative anemia. Lower preoperative hemoglobin (p<0.001) and non-tumor surgery (p<0.001) were predictive of postoperative anemia on multivariate analysis. Postoperative anemia resulted in increased RBC transfusion (p<0.001) and lower GCS score at discharge (p=0.012). Conclusions: Atleast one in ten patients undergoing elective neurosurgery develop postoperative anemia. Lower preoperative hemoglobin and non-tumor surgery predict anemia. Anemia results in increased RBC transfusion and lower discharge GCS score.

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.

Incidence, predictors, and impact of acute post-operative pain after cranial neurosurgery: A prospective cohort study.

Objectives: Pain is common after craniotomy. Its incidence and predictors in developing nations are not adequately studied. We aimed to assess the incidence, predictors, and impact of acute post-operative pain after intracranial neurosurgeries. Materials and Methods: This prospective observational study was conducted in adult patients undergoing intracranial neurosurgeries. After patient consent, ethics committee approval, and study registration, we assessed the incidence of post-operative pain using numerical rating scale (NRS) score. Predictors and impact of pain on patient outcomes were also evaluated. Results: A total of 497 patients were recruited during 10-month study period. Significant (4-10 NRS score) post-operative pain at any time-point during the first 3 days after intracranial neurosurgery was reported by 65.5% (307/469) of patients. Incidence of significant pain during the 1st post-operative h, on the 1st, 2nd, and 3rd post-operative days was 20% (78/391), 50% (209/418), 38% (152/401), and 24% (86/360), respectively. Higher pre-operative NRS score and pain during the 1st h post-operatively, predicted the occurrence of pain during the first 3 days after surgery, P = 0.003 and P < 0.001, respectively. Pain was significantly associated with poor sleep quality on the first 2 post-operative nights (P < 0.001). Patient satisfaction score was higher in patients with post-operative pain, P = 0.002. Conclusion: Every two in three patients undergoing elective intracranial neurosurgery report significant pain at some point during the first 3 postoperative days. Pre-operative pain and pain during 1st post-operative h predict the occurrence of significant post-operative pain.

Association between patient characteristics and dissatisfaction after cranial neurosurgery: A prospective observational study.

Objectives: Patient satisfaction is an indicator of the quality of healthcare. It can improve treatment adherence and health outcomes. This study aimed to determine the incidence, predictive factors, and impact of post-operative patient dissatisfaction with perioperative care after cranial neurosurgery. Materials and Methods: This was a prospective observational study conducted in a tertiary care academic university hospital. Adult patients undergoing cranial neurosurgery were assessed for satisfaction 24 h after surgery using a five-point scale. The data regarding patient characteristics that may predict dissatisfaction after surgery were collected along with ambulation time and hospital stay. Shapiro-Wilk test was used to assess normality of data. Univariate analysis was performed using Mann-Whitney U-test and significant factors were entered into binary logistic regression model for identifying predictors. The level of significance was set at P < 0.05. Results: Four hundred and ninety-six adult patients undergoing cranial neurosurgery were recruited into the study from September 2021 to June 2022. Data of 390 were analyzed. The incidence of patient dissatisfaction was 20.5%. On univariate analysis, literacy, economic status, pre-operative pain, and anxiety were associated with post-operative patient dissatisfaction. On logistic regression analysis, illiteracy, higher economic status, and no pre-operative anxiety were predictors of dissatisfaction. The patient dissatisfaction did not impact ambulation time or duration of hospital stay after the surgery. Conclusion: One in five patients reported dissatisfaction after cranial neurosurgery. Illiteracy, higher economic status, and no pre-operative anxiety were predictors of patient dissatisfaction. Dissatisfaction was not associated with delayed ambulation or hospital discharge.

Opioid versus Nonopioid Analgesia for Craniotomy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Despite the use of intraoperative opioid analgesia, postoperative pain is often reported by patients undergoing craniotomies. Opioids also cause undesirable side effects in neurosurgical patients. Hence, the role of nonopioid analgesia has been explored for craniotomies in recent years. METHODS: This systematic review evaluated evidence from randomized controlled trials (RCTs) comparing opioid and nonopioid analgesia during craniotomies regarding postoperative pain, recovery, and adverse events. RESULTS: Of the 10,459 records obtained by searching MEDLINE, Embase, and Web of Science databases, 6 RCTs were included. No difference was observed in pain scores between opioid and nonopioid analgesia at 1 and 24 hours after surgery: mean difference (MD), 1.11 units; 95% confidence interval [CI], -0.16 to 2.38, P = 0.09 and MD, -0.06 units; 95% CI, -1.14 to 1.01, P = 0.91, respectively. The time for first postoperative analgesic requirement was shorter with opioids but was not statistically significant (MD, -84.77 minutes; 95% CI, -254.65 to 85.11; P = 0.33). Postoperative nausea and vomiting (relative risk = 1.60; 95% CI, 0.96-2.66; P = 0.07) was similar but shivering (relative risk = 2.01; 95% CI, 1.09-3.71; P = 0.03) was greater in the opioid group than nonopioid group. CONCLUSIONS: There were no important differences in clinical outcomes between the groups in our review. The GRADE certainty of evidence was rated low for most outcomes. Available evidence does not suggest superiority of intraoperative nonopioid over opioid analgesia for postoperative pain in patients undergoing craniotomy. More studies are needed to firmly establish the role of nonopioid intraoperative analgesics as an alternative to opioids in this population.

Opioid versus non-opioid analgesia for spine surgery: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: Opioids are the primary analgesics used in patients undergoing spine surgery. Postoperative pain is common despite their liberal use and so are opioid-associated side effects. Non-opioid analgesics are gaining popularity as alternative to opioids in spine surgery. METHODS: This systematic review evaluated current evidence regarding opioid and non-opioid intraoperative analgesia and their influence on immediate postoperative pain and adverse events in spine surgery. RESULTS: A total of 10,459 records were obtained by searching Medline, EMBASE and Web of Science databases and six randomized controlled trials were included. Differences in postoperative pain scores between opioid and non-opioid groups were not significant at 1 h: 4 studies, mean difference (MD) = 0.65 units, 95% confidence intervals (CI) [-0.12 to 1.41], p = 0.10, but favored non-opioid at 24 h after surgery: 3 studies, MD = 0.75 units, 95%CI [0.03 to 1.46], p = 0.04. The time for first postoperative analgesic requirement was shorter (MD = -45.06 min, 95%CI [-72.50 to -17.62], p = 0.001), and morphine consumption during first 24 h after surgery was higher in opioid compared to non-opioid group (MD = 4.54 mg, 95%CI [3.26 to 5.82], p < 0.00001). Adverse effects of postoperative nausea and vomiting (Relative risk (RR) = 2.15, 95%CI [1.37 to 3.38], p = 0.0009) and shivering (RR = 2.52, 95%CI [1.08 to 5.89], p = 0.03) were higher and bradycardia was lower (RR = 0.35, 95%CI [0.17 to 0.71], p = 0.004) with opioid analgesia. CONCLUSION: The certainty of evidence on GRADE assessment is low for studied outcomes. Available evidence supports intraoperative non-opioid analgesia for overall postoperative pain outcomes in spine surgery. More research is needed to find the best drug combination and dosing regimen. Prospero Registration: CRD42020209042.

Trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) in neuroanesthesia practice: A review.

Respiratory management is an important aspect of care in neuroanesthesia practice for neurosurgical patients. A wide variety of procedures are performed under sedation in the neurosurgical population, and maintaining oxygenation is of paramount importance during these procedures. The high-flow oxygen devices improve arterial oxygenation by providing higher inspiratory oxygen concentration and maintaining higher dynamic positive airway pressure. These devices have gained importance during the recent years with regard to enhancing patient safety. This narrative review focuses on the role of trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) and high-flow nasal oxygenation (HFNO) techniques in the neuroanesthesia practice and electroconvulsive therapy.

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.

Effect of Preanesthetic Fluid Loading on Postinduction Hypotension and Advanced Cardiac Parameters in Patients with Chronic Compressive Cervical Myelopathy: A Randomized Controlled Trial.

Purpose Hypotension during the early intraoperative phase is common and can lead to adverse perioperative outcomes. Fluid preloading is one of the methods to limit its occurrence. Patients with chronic compressive cervical myelopathy may have autonomic dysfunction, which can aggravate hemodynamic alterations during anesthesia. This study compared the occurrence of postinduction hypotension and changes in cardiac dynamic indices in patients with and without crystalloid preloading undergoing decompressive cervical spine surgery. Methods This randomized controlled trial was conducted over 15 months after obtaining patient consent, approval of the institute ethics committee, and trial registration. We compared preanesthetic fluid loading with Ringer's lactate (20 mL/kg over 30 minutes) with no preloading (2 mL/kg/h maintenance) in 60 consecutive patients undergoing cervical spine surgery. The ANSiscope was used to determine baseline cardiac autonomic function. Noninvasive cardiac output monitor was used to assess changes in heart rate, mean arterial pressure, cardiac index (CI), stroke volume variation (SVV), and total peripheral resistance index during study intervention, anesthetic induction, tracheal intubation, and change in position from supine to prone. Results The incidences of postinduction hypotension were 26.7% (8/30) and 86.7% (26/30) and the median doses of mephentermine used were 0 and 6 mg, respectively, in patients with and without fluid preloading (both p < 0.001). Preloading resulted in improvement in CI, reduction in SVV, and lesser vasopressor use. Conclusion Preloading reduced the occurrence of postinduction hypotension and vasopressor use, improved CI, and reduced SVV during the early intraoperative period. Registration number of Clinical Trial The trial was registered with Clinical Trial Registry of India (CTRI/2018/07/014970 on 19/07/2018).

Effect of Respiratory Physiological Changes on Optic Nerve Sheath Diameter and Cerebral Oxygen Saturation in Patients With Acute Traumatic Brain Injury.

BACKGROUND: Severe traumatic brain injury (TBI) results in raised intracranial pressure (ICP). Ultrasonographic measurement of the optic nerve sheath diameter (ONSD) is a noninvasive method for the assessment of raised ICP. Manipulation of positive end-expiratory pressure (PEEP) and end-tidal carbon dioxide (ETCO2) are often used to optimize ICP and improve oxygenation in TBI patients. This study evaluated the effects of PEEP and ETCO2 on ONSD and regional cerebral oxygen saturation (rScO2) in patients with acute TBI. METHODS: A total of 14 patients (11 males) aged older than 18 years with acute severe TBI were included in this study. ONSD and rScO2 were assessed before and after changes in PEEP from 5 to 10 cm H2O and in ETCO2 from 40 to 30 mm Hg on both pathologic and nonpathologic sides. RESULTS: Increasing PEEP and reducing ETCO2 resulted in changes in ONSD and rScO2 on both pathologic and nonpathologic sides. On the pathologic side, ONSD and rScO2 were highest with a PEEP of 10 cm H2O:ETCO2 40 mm Hg combination and lowest with PEEP of 5 cm H2O:ETCO2 30 mm Hg (ONSD 5.24±0.49 vs. 4.27±0.36 mm, P<0.001; rScO2 70.7±9.91% vs. 66.3±9.75%, P<0.001); both PEEP and ETCO2 had significant effects on ONSD and rScO2 (P<0.001). On the nonpathologic side, ONSD and rScO2 were highest and lowest with PEEP of 10 cm H2O:ETCO2 40 mm Hg and PEEP of 5 cm H2O:ETCO2 30 mm Hg combinations, respectively (ONSD: 4.93±0.46 vs. 4.02±0.40 mm, P<0.001; rScO2: 74.77±8.30% vs. 70.69±8.12%, P<0.001). ETCO2 had a significant effect on rScO2 (P<0.001), but the impact of PEEP on rScO2 was not statistically significant (P=0.05). CONCLUSION: Increasing PEEP resulted in significant increases in ONSD and rScO2, whereas reducing ETCO2 significantly decreased ONSD and rScO2.

Ultrasound-Guided Erector Spinae Plane Block for Perioperative Analgesia in Cervical and Thoracic Spine Surgeries - A Case Series.

Erector spinae plane (ESP) block is a recently introduced regional technique for pain management. However, its usefulness for perioperative analgesia in cervical and thoracic spine surgeries is underutilized. In this case series, we reviewed the case records of seven patients who received ultrasound-guided ESP block for perioperative analgesia for cervical and thoracic spine surgeries during a two-month period. We evaluated the performance of the ESP block with regards to intraoperative nociception and hemodynamics, postoperative pain, and need of rescue analgesia in these patients. The median age of our patients was 28 years (range 5-74 years) and the duration of surgery was 300 minutes (range 240-540 minutes). The surgical pleth index, a marker of intraoperative nociception, was below the threshold of 50 at most time-points during the surgery. Similarly, intraoperative hemodynamic parameters (HR and BP) were stable throughout the surgery. Postoperative pain control was good during the initial 48 after surgery with median NRS score of 2 at rest and 4 with movement. The ESP block results in good intraoperative and postoperative analgesia and also provides hemodynamic stability and opioid-sparing effect for cervical and thoracic spine surgeries.

Perioperative Analgesia in Neurosurgery (PAIN): A national survey of pain assessment and management among neuroanesthesiologists of India.

BACKGROUND: Perioperative pain assessment and management in neurosurgical patients varies widely across the globe. There is lack of data from developing world regarding practices of pain assessment and management in neurosurgical population. This survey aimed to capture practices and perceptions regarding perioperative pain assessment and management in neurosurgical patients among anesthesiologists who are members of the Indian Society of Neuroanaesthesiology and Critical Care (ISNACC) and evaluated if hospital and pain characteristics predicted the use of structured pain assessment protocol and use of opioids for postoperative pain management. METHODS: A 26-item English language questionnaire was administered to members of ISNACC using Kwiksurveys platform after ethics committee approval. Our outcome measures were adoption of structured protocol for pain assessment and opioid usage for postoperative pain management. RESULTS: The response rate for our survey was 55.15% (289/524). One hundred eighteen (41%) responders informed that their hospital setup had a structured pain protocol while 43 (15%) responders reported using opioids for postoperative pain management. Predictors of the use of structured pain protocol were private setup (odds ratio [OR] 2.64; 95% confidence interval [CI] 1.52-4.59; P = .001), higher pain intensity (OR 0.37; 95% CI 0.21-0.64; P < .001) and use of pain scale (OR 7.94; 95% CI 3.99-15.81; P < .001) while availability of structured pain protocol (OR 2.04; 95% CI 1.02-4.05; P = .043) was the only significant variable for postoperative opioid use. CONCLUSIONS: Less than half of the Indian neuroanesthesiologists who are members of ISNACC use structured protocol for pain assessment and very few use opioids for postoperative pain management in neurosurgical patients.

Effect of Opioid Versus Non-Opioid Analgesia on Surgical Pleth Index and Biomarkers of Surgical Stress During Neurosurgery for Brain Tumors: Preliminary Findings.

BACKGROUND: Stress response to surgery is mediated by the sympathetic nervous system and manifests as changes in hemodynamic and neuroendocrine parameters. Recently, the surgical pleth index (SPI) is employed for objective and continuous monitoring of nociceptive response during surgery. Opioids are the mainstay of managing stress response to nociception during the perioperative period. However, due to the well-known adverse effects of opioids, α2 agonists are increasingly used to ablate stress response and reduce opioid usage. OBJECTIVES: This study compared SPI and biomarkers of surgical stress between opioid (fentanyl) and non-opioid (dexmedetomidine) analgesia during craniotomy. METHODS: Patients aged 18 to 60 years undergoing elective craniotomies for brain tumor resection under general anesthesia were randomized to receive fentanyl 1 µg/kg/h or dexmedetomidine 0.5 µ/kg/h infusion as the primary intraoperative analgesic. Our objective was to compare SPI and biomarkers of surgical stress-serum cortisol, blood glucose, arterial pH, and leucocyte count between the two groups. RESULTS: Data of all 24 patients recruited into the study were analyzed. There was no difference in the demographic parameters between the groups. The SPI remained similar with both the drugs over various time points during the study period. There was no difference between the groups in the biomarkers of surgical stress-cortisol, blood glucose, and pH while leucocyte count was higher in the fentanyl group. CONCLUSIONS: The stress response to surgery during craniotomy for brain tumors is similar with opioid (fentanyl) and non-opioid (dexmedetomidine) analgesia as assessed by SPI and blood markers such as cortisol, glucose, and pH.