Perioperative Glycemia Management in Patients Undergoing Craniotomy for Brain Tumor Resection: A Global Survey of Neuroanesthesiologists' Perceptions and Practices

OBJECTIVE

There is a paucity of clinical evidence that guides perioperative glycemia management in patients undergoing craniotomy for brain tumor resection. The purpose of this study was to better understand global perceptions and practices related to glycemia management in these patients.

METHODS

Neuroanesthesiologists throughout North America, South America, Europe, and Asia filled out a brief online questionnaire related to their perceptions and practices regarding glycemia management in patients undergoing craniotomy for brain tumor resection.

RESULTS

Over 4 weeks, 435 participants practicing in 34 countries across 6 continents participated in this survey. Although responders in North America were found to perceive a higher risk hyperglycemia compared with those practicing in European (P = 0.024) and South Asian (P = 0.007) countries, responders practicing in South Asian countries (P = 0.030), Middle Eastern countries (P = 0.029), and South American (P = 0.005) countries were more likely than those from North America to remeasure glucose after an initial normal glucose measurement at incision. Responders from North America reported that a higher blood glucose threshold was necessary for them to delay or cancel the surgery compared with responders in Slavic (P < 0.001), European (P = 0.002), South American (P = 0.002), and Asian and Pacific (P < 0.001) countries. Responders from North America were more likely to report that they would delay or cancel the surgery because of a higher blood glucose threshold.

CONCLUSIONS

Our survey results suggest that perceptions and practices related to blood glucose management in patients undergoing brain tumor resection are variable. This study highlights the need for stronger clinical evidence and guidelines to help guide decisions for when and how to manage blood glucose derangements in these patients.

Anesthetic protocol for right ventricular dysfunction management in heart transplantation: systematic review, development and validation

BACKGROUND

Right Ventricular Dysfunction (RVD) is the most frequent intraoperative hemodynamic complication in Heart Transplantation (HTx). RVD occurs in 0.04-1.0% of cardiac surgeries with cardiotomy and in 20-50% of HTx, with mortality up to 75%. No consensus has been established for how anesthesiologists should manage RVD, with management methods many times remaining unvalidated.

METHODS

We conducted a systematic review, following PRISMA guidelines, to create an anesthetic protocol to manage RVD in HTx, using databases that include PubMed and Embase, until September 2018 based on inclusion and exclusion criteria. The articles screening for the systematic review were done two independent reviewers, in case of discrepancy, we consulted a third independent reviewer. Based on the systematic review, the anesthetic protocol was developed. The instrument selected to perform the validation of the protocol was AGREE II, for this purpose expert anesthetists were recruited to do this process. The minimum arbitration score for domains validation cutoff of AGREE II is arbitered to 70%. This study was registered at PROSPERO (115600).

RESULTS

In the systematic review, 152 articles were included. We present the protocol in a flowchart with six steps based on goal-directed therapy, invasive monitoring, and transesophageal echocardiogram. Six experts judged the protocol and validated it.

CONCLUSION

The protocol has been validated by experts and new studies are needed to assess its applicability and potential benefits on major endpoints.

[Update on perioperative hypersensitivity reactions: joint document from the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part II: etiology and diagnosis]

This second joint document, written by experts from the Brazilian Association of Allergy and Immunology (ASBAI) and Brazilian Society of Anesthesiology (SBA) concerned with perioperative anaphylaxis, aims to review the pathophysiological reaction mechanisms, triggering agents (in adults and children), and the approach for diagnosis during and after an episode of anaphylaxis. As anaphylaxis assessment is extensive, the identification of medications, antiseptics and other substances used at each setting, the comprehensive data documentation, and the use of standardized nomenclature are key points for obtaining more consistent epidemiological information on perioperative anaphylaxis.

[Update on perioperative hypersensitivity reactions: joint document of the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part I: post-crisis guidelines and treatment]

Experts from the Brazilian Association of Allergy and Immunology (ASBAI) and the Brazilian Society of Anesthesiology (SBA) interested in the issue of perioperative anaphylaxis, and aiming to strengthen the collaboration between the two societies, combined efforts to study the topic and to prepare a joint document to guide specialists in both areas. The purpose of the present series of two articles was to report the most recent evidence based on the collaborative assessment between both societies. This first article will consider the updated definitions, treatment and guidelines after a perioperative crisis. The following article will discuss the major etiologic agents, how to proceed with the investigation, and the appropriate tests.

Monitoring of coagulation by intraoperative thromboelastometry of liver transplantation in a patient using warfarin – case report

Introduction

Case report

Discussion

[Monitoring of coagulation by intraoperative thromboelastometry of liver transplantation in a patient using warfarin - case report]

INTRODUCTION

Advanced hepatic disease may - in addition to the widely recognized hemorrhagic complications - occur with thrombotic events. We describe the case of a cirrhotic patient taking warfarin and whose coagulation management during liver transplantation was guided by thromboelastometry (ROTEM^®).

CASE REPORT

A 56 year-old male patient diagnosed with alcohol cirrhosis using warfarin (2.5mg.day^-1) for partial portal vein thrombosis with the International Normalized Ratio (INR) of 2.14. At the beginning of surgery, the ROTEM^® parameters were all normal. In the anhepatic phase, EXTEM and INTEM remained normal, but FIBTEM showed reduction of amplitude after 10min and maximum clot firmness. Finally, in the neohepatic phase, there was a slight alteration in the hypocoagulability of most of the parameters of the EXTEM, INTEM and FIBTEM, besides a notable correction of the Coagulation Time (CT) in HEPTEM compared to the CT of the INTEM. Therefore, the patient did not receive any transfusion of blood products during surgery and in the postoperative period, being discharged on the 8th postoperative day.

DISCUSSION

Coagulation deficit resulting from cirrhosis distorts INR as a parameter of anticoagulation adequacy and as a determinant of the need for blood transfusion. Thus, thromboelastometry can provide important information for patient management.

Influence of total intravenous anesthesia, entropy and laparoscopy on oxidative stress

BACKGROUND AND OBJECTIVES

Recent studies have correlated postoperative mortality with anesthetic mortality, especially with the depth of anesthesia and systolic blood pressure (SBP). The aim of this study is to evaluate the effects of the depth of total intravenous anesthesia (TIVA) using remifentanil and propofol, performed with monitoring of response entropy (RE) on blood concentrations of oxidative stress markers (TBARS and glutathione) during laparoscopic operations.

METHOD

Twenty adult patients, ASA I, BMI 20-26 kg.m(-2), aged 20 to 40 years, were randomly distributed into two groups: Group I underwent anesthetic-surgical procedure with RE maintained between 45 and 59, and Group II underwent anesthetic-surgical procedure with RE between 30 and 44. In both groups, the remifentanil and propofol infusion was controlled by the effector site (Es), adjusted to maintain RE desired values (Groups I and II) and always assessing the suppression rate (SR). Patients were evaluated in six periods: M1 (immediately before anesthesia), M2 (before tracheal intubation [TI]), M3 (5-minutes after TI), M4 (immediately before pneumoperitoneum [PPT]), M5 (1-minute after PPT), and M6 (1-hour after the operation). The following parameters were assessed at all times: SBP, DBP, HR, RE, SR, TBARS, and glutathione.

RESULTS

We found increases in TBARS and glutathione in M5, both in Group I and Group II (p<0.05), with higher values in Group II, and SR in three patients in Group II, immediately after PPT.

CONCLUSIONS

Increased markers in Group I (M5) suggests an increase in anaerobic metabolism (AM) in the splanchnic circulation while the highest values seen in Group II (GII > GI in M5, p<0.05%) suggest interference of another factor (deep anesthesia) responsible for the increase in AM, probably as a result of increased autonomic nervous system depression and minor splanchnic self-regulation.

Anesthetics, cerebral protection and preconditioning

BACKGROUND AND OBJECTIVES

Several studies demonstrate that cerebral preconditioning is a protective mechanism against a stressful situation. Preconditioning determinants are described, as well as the neuroprotection provided by anesthetic and non-anesthetics agents.

CONTENT

Review based on the main articles addressing the pathophysiology of ischemia-reperfusion and neuronal injury and pharmacological and non-pharmacological factors (inflammation, glycemia, and temperature) related to the change in response to ischemia-reperfusion, in addition to neuroprotection induced by anesthetic use.

CONCLUSIONS

The brain has the ability to protect itself against ischemia when stimulated. The elucidation of this mechanism enables the application of preconditioning inducing substances (some anesthetics), other drugs, and non-pharmacological measures, such as hypothermia, aimed at inducing tolerance to ischemic lesions.

Anesthetics, cerebral protection and preconditioning

BACKGROUND AND OBJECTIVES

Several studies demonstrate that cerebral preconditioning is a protective mechanism against a stressful situation. Preconditioning determinants are described, as well as the neuroprotection provided by anesthetic and non-anesthetics agents.

CONTENT

Review based on the main articles addressing the pathophysiology of ischemia-reperfusion and neuronal injury and pharmacological and non-pharmacological factors (inflammation, glycemia, and temperature) related to the change in response to ischemia-reperfusion, in addition to neuroprotection induced by anesthetic use.

CONCLUSIONS

The brain has the ability to protect itself against ischemia when stimulated. The elucidation of this mechanism enables the application of preconditioning inducing substances (some anesthetics), other drugs, and non-pharmacological measures, such as hypothermia, aimed at inducing tolerance to ischemic lesions.

Bispectral index and other processed parameters of electroencephalogram: an update

BACKGROUND AND OBJECTIVES

The processed analysis of electroencephalogram became extremely important to monitor nervous system, being used to obtain a better anesthetic adequacy. The objective was to conduct a review about each processed parameter, defining its real importance.

CONTENT

A review was conducted showing mathematical, physical and clinical aspects as well as their correlations and updates, presenting new integrated parameters.

CONCLUSIONS

An adequate analysis of processed parameters of electroencephalogram may provide more intraoperative safety as well as result in a better outcome for the patient.

[Effects of sedation produced by the association of midazolam and ketamine s(+) on encephalographic variables]

BACKGROUND AND OBJECTIVES

Ketamine S(+) is important in pain modulation in surgical patients. The objective of the present study was to evaluate the relationship between the levels of sedation produced by low doses of ketamine S(+), as well as encephalographic variables: BIS, SEF 95%, pEMG, suppression rate, and presence of burst-suppression.

METHODS

Thirty patients of both sexes, aged 25-50 years, were randomized into three groups. Group G1 (10) received intravenous ketamine S(+) 0.050 mg,kg(-1); group G2 (10) intravenous ketamine S(+) 0.125 mg.kg(-1); and group G3 (10) intravenous ketamine S(+) 0.250 mg.kg(-1). All patients received 0.08 mg.kg(-1) of intravenous midazolam 10 minutes before administration of ketamine S(+). In each group, two moments were evaluated: M1, before ketamine S(+) administration; and M2, after ketamine S(+) administration. Sedation levels and encephalographic variables: BIS, SEF 95%, pEMG, suppression rate, and the presence of burst-suppression were evaluated in all patients before and after ketamine S(+) administration. ANOVA was used for repeated measurements and the p-value was adjusted for multiple comparisons by Tukey's test.

RESULTS

A decrease in alertness-sedation scale scores was observed in all three groups in moment M2. Electroencephalographic variables showed significant variation in all three groups when moments M1 and M2 were compared, both in pEMG and BIS (p < 0.05).

CONCLUSIONS

Sedation levels showed significant correlation with the increase in ketamine S(+) dosage. However, increased BIS levels may have reflected increased pEMG induced by ketamine S(+).

[Spectral entropy: a new method for anesthetic adequacy.]

BACKGROUND AND OBJECTIVES

Though universally employed, clinical signs to evaluate anesthetic adequacy are not reliable. Over the past years several pieces of equipment have been devised to improve intraoperative handling of anesthetic drugs, some of them directly measuring cerebral cortical activity (hypnosis). None of them, however, has offered the possibility of directly evaluating sub-cortical activity (motor response).

CONTENTS

Spectral entropy measures irregularity, complexity or amount of EEG disorders and has been proposed as indicator of anesthetic depth. Signal is collected from the fronto-temporal region and processed according to Shannon's equation (H = - Sp k log p k, where p k represents the probability of a discrete k event), resulting in two types of analyses: 1) state entropy (SE), which evaluates cerebral cortex electrical activity (0.8 - 32Hz) and 2) response entropy (RE), containing both subcortical electromyographic and cortical electroence- phalographic components and analyzes frequencies in the range 0.8 - 47Hz.

CONCLUSIONS

Frontal muscles activation may indicate inadequacy of the subcortical component (nociception). Such activation appears as a gap between SE and RE. This, it is possible to directly evaluate both cortical (SE) and subcortical (RE) components providing better anesthetic adequacy.

Influence of dexmedetomidine upon sevoflurane end-expiratory concentration. Evaluation by bispectral index, suppression rate and electroencephalographic power spectral analysis

BACKGROUND AND OBJECTIVES

Dexmedetomidine, an alpha2-adrenergic agonist, has been described as being able to decrease the demand for both venous and inhalational agents. This study aimed at evaluating the influence of Dexmedetomidine upon sevoflurane end-expiratory concentration (EC) with monitoring the depth of anesthesia.

METHODS

Participated in this study 40 female adult patients, physical status ASA I, submitted to gynecological laparoscopy under general anesthesia maintained with sevoflurane, who were randomly divided in two groups: Group I (n=20), without dexmedetomidine; and Group II (n=20), with dexmedetomidine, in continuous infusion, as follows: Rapid phase (1 microg kg(-1) in 10 min(-1)) 10 minutes before anesthesia induction, followed by a maintenance phase (0.4 microg kg(-1) h(-1)) throughout the surgery. The following parameters were analyzed: BP, HR, BIS, SEF 95%, delta%, suppression rate (SR), rSO2, CE, SpO2 and P(ET)CO2, in the following moments: M1 - before dexmedetomidine or 0.9% saline infusion; M2 - prior to intubation; M3 - following intubation; M4 - before incision; M5 - following incision; M6 - before CO2 inflation; M7 - following CO2 inflation; M8 - 10 min after CO2 inflation; M9 - 10 min after M8; M10 - 20 min after M8; M11 - 30 min after M8; M12 - 40 min after M8; and M13 - at emergence. Time for emergence and hospital discharge were also recorded.

RESULTS

Dexmedetomidine has decreased sevoflurane end-expiratory concentration from M4 to M13 (p<0.05) when comparing Group I and Group II. No clinically significant changes were observed in hemodynamic parameters. Time for emergence in Groups I and II was 11 +/- 0.91 min. and 6.35 +/- 0.93 min., respectively (p < 0.05). Time for hospital discharge was 7.45 +/- 0.69 h in Group I and 8.37 +/- 0.88 h in Group II (p < 0.05).

CONCLUSIONS

Dexmedetomidine was effective in decreasing sevoflurane end-expiratory concentration while maintaining hemodynamic stability without impairing time for hospital discharge, in addition to promoting an earlier emergence.

Electrocochleographic effects of ear canal pressure change

A series of Swedish studies has shown that the application of middle ear over-pressure may be effective in ameliorating the symptoms associated with Meniere's disease. Other studies have shown that electrocochleography (ECochG) is an effective tool in the identification of Meniere's disease, especially in the presence of active symptoms. Based on the therapeutic potential of middle ear overpressure as a treatment for Meniere's symptoms and on the relationship between these symptoms and ECochG, we investigated the effects of ear canal pressure change on human electrocochleographic components in normally hearing subjects. An experimental system combining an immittance audiometer probe and ear canal electrode was utilized to record extratympanic ECochG when different atmospheric pressures were applied indirectly to the middle ear via the sealed ear canal. All ECochG parameters except for the duration of the whole nerve action potential (AP) of the auditory nerve were significantly affected by pressure changes in the ear canal. Effects included an enlargement of the summating potential (SP) amplitude and of the SP:AP amplitude ratio at pressures above and below 0 decaPa (daPa). An important implication of our findings is that the status of the middle ear must be taken into account in the interpretation of ECochG results.