Opioid-free general anesthesia: considerations, techniques, and limitations.

PURPOSE OF REVIEW: To discuss the role of opioids during general anesthesia and examine their advantages and risks in the context of clinical practice. We define opioid-free anesthesia (OFA) as the absolute avoidance of intraoperative opioids. RECENT FINDINGS: In most minimally invasive and short-duration procedures, nonopioid analgesics, analgesic adjuvants, and local/regional analgesia can significantly spare the amount of intraoperative opioid needed. OFA should be considered in the context of tailoring to a specific patient and procedure, not as a universal approach. Strategies considered for OFA involve several adjuncts with low therapeutic range, requiring continuous infusions and resources, with potential for delayed recovery or other side effects, including increased short-term and long-term pain. No evidence indicates that OFA leads to decreased long-term opioid-related harms. SUMMARY: Complete avoidance of intraoperative opioids remains questionable, as it does not necessarily ensure avoidance of postoperative opioids. Multimodal analgesia including local/regional anesthesia may allow OFA for selected, minimally invasive surgeries, but further research is necessary in surgeries with high postoperative opioid requirements. Until there is definitive evidence regarding procedure and patient-specific combinations as well as the dose and duration of administration of adjunct agents, it is imperative to practice opioid-sparing approach in the intraoperative period.

Anaesthesia for mechanical thrombectomy: a narrative review.

Stroke is a leading cause of death and disability, and is associated with a huge societal and economic burden. Interventions for the immediate treatment of ischaemic stroke due to large vessel occlusion are dependent on recanalisation of the occluded vessel. Trials have provided evidence supporting the efficacy of mechanical thrombectomy in ischaemic stroke due to large vessel occlusion. This has resulted in changes in management and organisation of stroke care worldwide. Major determinants of effectiveness of thrombectomy include: time between stroke onset and reperfusion; location of occlusion and local collateral perfusion; adequacy of reperfusion; patient age; and stroke severity. The role of anaesthetic technique on outcome remains controversial with published research showing conflicting results. As a result, choice of conscious sedation or general anaesthesia for mechanical thrombectomy is often dependent on individual operator choice or institutional preference. More recent randomised controlled trials have suggested that protocol-driven general anaesthesia is no worse than conscious sedation and may even be associated with better outcomes. These and other studies have highlighted the importance of optimal blood pressure management as a major determinant of patient outcome. Anaesthetic management should be tailored to the individual patient and circumstances. Acute ischaemic stroke is a neurological emergency; clinicians should focus on minimising door-to-groin puncture time and the provision of high-quality periprocedural care with a particular emphasis on the maintenance of an adequate blood pressure.

General Anesthesia With and Without Remifentanil for Flexible and Rigid Bronchoscopy: A Retrospective Case-Matched Study.

Prior research suggests general anesthesia (GA) with remifentanil is superior to GA without remifentanil regarding perioperative outcomes, including the postanesthesia care unit (PACU) length of stay (LOS). The objective of this study was to compare the intraoperative management and PACU LOS in patients who underwent GA with or without remifentanil for bronchoscopy. The study included 5,763 adult patients who underwent flexible bronchoscopy and received GA with or without remifentanil or who underwent rigid bronchoscopy and received GA with or without remifentanil. Despite prolonged procedural length in both the flexible and rigid bronchoscopy groups and greater ASA score in the flexible bronchoscopy group, no difference in the adjusted PACU LOS or time to extubation was found. Remifentanil was associated with hemodynamic perturbations and desaturation events. Remifentanil was associated with a significant reduction in nonremifentanil opioid requirements. Although both groups receiving remifentanil were associated with a less favorable intraoperative hemodynamic profile, remifentanil did not increase the incidence of postoperative complications despite that group having a greater ASA score and procedural duration.

"The Worst Is the Worry": Importance of Preoperative Preparation of Preschool Children.

Children often experience a high level of anxiety before anesthesia, which may lead to poor cooperation during anesthesia induction and negative consequences for the postoperative period. The aim of this study was to obtain knowledge that may improve practice in preparing preschoolers for anesthesia and surgery by analyzing nurse anesthetists' preoperative experiences with children. A focus group interview with nurse anesthetists was conducted. The interview was recorded and transcribed verbatim, and results were analyzed using qualitative text analysis. Three main themes were identified to relieve preschoolers' anxiety: "Making the unknown and scary harmless," "Using oneself," and "Having a lap to sit on." Findings indicate that explanation and preparation through play, as well as experiences of participation and coping, can safeguard children who are feeling anxious. The professional and personal qualities of a Certified Registered Nurse Anesthetist (CRNA) are important when managing pediatric patients' anxiety. It is essential that CRNAs have the ability to adapt the induction of anesthesia to suit the child individually (and parents). The parents constitute an important collaborator for CRNAs. Young children need explanations and knowledge about what is happening and what to expect. CRNAs should focus on codetermination and participation for preschool children undergoing anesthesia.

Comparison of the ED50 propofol requirements during the insertion of laryngeal mask airway Ambu AuraFlex with Ambu AuraOnce in children undergoing strabismus surgery.

WHAT IS KNOWN AND OBJECTIVE: Optimal airway management is crucial in strabismus surgery due to the inaccessibility of the airway throughout the procedure. Laryngeal mask airway offers advantages over tracheal intubation in ophthalmic surgery as it does not increase the intraocular pressure. The purpose of this study was to determine the median effective dose of propofol required, when combined with 0.2 µg/kg of sufentanil, for smooth insertion of Ambu AuraFlex in the first attempt in children undergoing strabismus surgery, and to compare it with that for Ambu AuraOnce. METHODS: Forty-three paediatric patients undergoing strabismus surgery under general anaesthesia were recruited. For induction, the initial dosage of propofol was 2 mg/kg in the AuraOnce group or 3 mg/kg in the AuraFlex group. In accordance with Dixon's up-and-down method, the dose of propofol for consecutive patients in each group was adjusted in increments or decrements of 0.25 mg/kg based on the previous patient's "three-point, six-category scale" response to the first attempt of insertion of the randomized device. Insertion of the device was attempted when the bispectral index was ≤60 for 5 s after propofol administration without the use of neuromuscular blocking agents. RESULTS AND DISCUSSION: The median effective dose (95% confidence interval) of propofol was significantly lower in the Ambu AuraOnce group than in the Ambu AuraFlex group (1.92 [1.50-2.32] mg/kg vs. 2.98 [2.49-3.94] mg/kg; p = 0.002). The incidence of dislodgement of the device was significantly higher with the use of the Ambu AuraOnce than with the use of AuraFlex (p = 0.023), whereas insignificant differences were observed between the two groups in the incidence of other perioperative adverse events. WHAT IS NEW AND CONCLUSION: Ambu AuraFlex requires a significantly higher dose of propofol for insertion and provides more effective and stable airway management in strabismus surgery than AuraOnce.

Acupuntura en la recuperación de la anestesia general en pacientes intervenidas quirúrgicamente de nódulo de mama / Acupuncture in the recovery from general anesthesia in patients who underwent a breast nodule surgery

RESUMEN Introducción: en el período de recuperación de la anestesia general se deben metabolizar los medicamentos empleados y restablecer las alteraciones fisiológicas. La acupuntura es un método de tratamiento que ha sido estudiado en el período perioperatorio con diferentes fines; sin embargo, es menos conocido su efecto en la recuperación de la anestesia general. Objetivo: describir el efecto de la estimulación con Acupuntura en la recuperación de la anestesia general balanceada en pacientes intervenidas quirúrgicamente por nódulo de mama. Materiales y métodos: se realizó un estudio observacional prospectivo, en 60 pacientes intervenidas quirúrgicamente de nódulo de mama con anestesia general endotraqueal balanceada, de enero de 2014 a enero de 2016, en el Hospital Provincial Docente José Ramón López Tabrane, de Matanzas. Se conformaron dos grupos: grupo I, al que al finalizar la cirugía se le colocaron agujas de acupuntura en los puntos R1, Du26 y P9; y grupo II, al que no se le realizó acupuntura. El efecto de la acupuntura en la recuperación anestésica se midió a través de la Escala de Aldrete. Resultados: la edad de mayor incidencia fue de 40 a 49 años. El estado físico de las pacientes, según la Sociedad Americana de Anestesiología, es I. Prevaleció un tiempo anestésico de 61 a 90 minutos. Más del 75 % de las féminas tuvieron un tiempo de recuperación anestésica entre 31 y 60 minutos. Se presentaron dos complicaciones leves atribuibles a la acupuntura. Conclusiones: la aplicación de la acupuntura acortó el tiempo de recuperación anestésica en las pacientes estudiadas (AU).

ABSTRACT Introduction: in the recovery period from general anesthesia the used drugs should be metabolized and the physiological alterations restored. Acupuncture is a treatment method that has been studied in the perioperative period with different aims; nevertheless its effect on the recovery from general anesthesia is less well known. Objective: to describe the acupuncture stimulation effect on the recovery from general balanced anesthesia in patients who underwent a breast nodule surgery. Materials and methods: a prospective, observational study was performed in 60 patients who underwent a surgery of breast nodule with balanced endotracheal general anesthesia, from January 2014 to January 2016, at the Provincial Teaching Hospital "Jose Ramon Lopez Tabrane" of Matanzas. Two groups were formed: group I included patients to whom acupuncture needles were placed in R1, Du 26 and P9 acupoints after surgery, and Group II patients to whom acupuncture was not performed. The acupuncture effect on anesthetic recovery was assessed using the Aldrete Scale. Two groups were formed: group I, whose members at the end of the surgery were placed acupuncture needles to in the points R1, Du26 and P9; and group II, whose members did not receive acupuncture. The effect of acupuncture on anesthetic recovery was measured through the Aldrete Scale. Results: the highest incidence age was 40 to 49 years. The physical condition of the patients, according to the American Society of Anesthesiology, was I. An anesthetic time of 61 to 90 minutes prevailed. More than 75% of the women had an anesthetic recovery time between 31 and 60 minutes. There were two minor complications attributable to acupuncture. Conclusions: acupuncture application shortened the anesthetic recovery time in the studied patients (AU).

The Role of Anesthesiologists in Perioperative Limitation of Potentially Life-Sustaining Medical Treatments: A Narrative Review and Perspective.

No patient arrives at the hospital to undergo general anesthesia for its own sake. Anesthesiology is a symbiont specialty, with the primary mission of preventing physical and psychological pain, easing anxiety, and shepherding physiologic homeostasis so that other care may safely progress. For most elective surgeries, the patient-anesthesiologist relationship begins shortly before and ends after the immediate perioperative period. While this may tempt anesthesiologists to defer goals of care discussions to our surgical or primary care colleagues, we have both an ethical and a practical imperative to share this responsibility. Since the early 1990s, the American College of Surgeons (ACS), the American Society of Anesthesiologists (ASA), and the Association of Perioperative Registered Nurses (AORN) have mandated a "required reconsideration" of do-not-resuscitate (DNR) orders. Key ethical considerations and guiding principles informing this "required reconsideration" have been extensively discussed in the literature and include respect for patient autonomy, beneficence, and nonmaleficence. In this article, we address how well these principles and guidelines are translated into daily clinical practice and how often anesthesiologists actually discuss goals of care or potential limitations to life-sustaining medical treatments (LSMTs) before administering anesthesia or sedation. Having done so, we review how often providers implement goal-concordant care, that is, care that reflects and adheres to the stated patient wishes. We conclude with describing several key gaps in the literature on goal-concordance of perioperative care for patients with limitations on LSMT and summarize novel strategies and promising efforts described in recent literature to improve goal-concordance of perioperative care.

Ultrasound-guided versus Shikani optical stylet-aided tracheal intubation: a prospective randomized study.

BACKGROUND: To compare ultrasound-guided tracheal intubation (UGTI) versus Shikani optical stylet (SOS)-aided tracheal intubation in patients with anticipated normal airway. METHODS: Sixty patients aged 18-65 years old who presented for elective surgery under general anesthesia were recruited in this prospective randomized study. They were assigned into two equal groups, either an ultrasound-guided group (Group UG, n = 30) or an SOS-aided group (Group SOS, n = 30). After the induction of anesthesia, the tracheal intubation was performed by a specified skilled anesthesiologist. The number of tracheal intubation attempt and the duration of successful intubation on the first attempt were recorded. Complications relative to tracheal intubation including desaturation, hoarseness and sore throat were also recorded. RESULTS: The first-attempt success rate is 93.3% (28/30) in Group UG and 90% (27/30) in Group SOS (P = 0.640). The second-attempt was all successful for the 2 and 3 patients left in the two groups, and the overall success rate of both groups was 100%. The duration of successful intubation on the first attempt of Group UG was not significantly different from that of Group SOS (34.0 ± 20.8 s vs 35.5 ± 23.2 s, P = 0.784). One patient in Group SOS had desaturation (P = 0.313), and there was none hoarseness in the two groups. Sore throat was detected in both group (4 in Group UG, 5 in Group SOS, P = 0.718). CONCLUSION: Ultrasound-guided tracheal intubation was as effective as Shikani optical stylet-aided tracheal intubation in adult patients with anticipated normal airway. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR-IIC-17010875 . Date of Registration: 15 March 2017.

Prospective Evaluation of a Standardized Opioid Reduction Protocol after Anorectal Surgery.

BACKGROUND: Surgery for anorectal disease is thought to cause significant postoperative pain. Our previous work demonstrated that most opioids prescribed after anorectal surgery are not used. We aimed to evaluate a standardized protocol for pain control after anorectal surgery. METHODS: We prospectively evaluated a standardized opioid reduction protocol over a 13-mo period for all patients undergoing elective anorectal surgery at our institution. Protocol components include preoperative query, procedural local-anesthetic blocks, first-line nonopioid analgesic use ± opioid prescription of five pills, and standardized postoperative instructions. Patients completed questionnaires at postoperative follow-up. Patients with history of opioid abuse or use within 30 d of operation, loss to follow-up, or surgical complications were excluded. Primary outcome was quality of pain control on a five-point scale. Secondary outcomes included use of nonopioid analgesics, opioids used, and need for refill. RESULTS: A total of 55 patients were included. Mean age was 47 ± 17 y with 23 women (42%). Anorectal abscess/fistula procedures were the most common (69%) followed by pilonidal procedures (11%) and hemorrhoidectomy (7%). Most had general anesthesia (60%) with the remainder local anesthesia ± sedation. Fifty-four (98%) had procedural local-anesthetic blocks. Twenty-six patients (47%) were prescribed opioids with a median of five pills. Forty-seven patients (85%) reported the use of nonopioid analgesics. Forty-six patients (84%) reported excellent to very good pain control. About 220 opioid pills were prescribed, and 122 were reported to be used. One patient (2%) received an opioid refill. CONCLUSIONS: Satisfactory pain control after anorectal surgery can be achieved with multimodality therapy with little to no opioid use for most patients.

Improving pain management for children having dental extractions under general anaesthesia.

Children provided with general anaesthesia for dental extractions at East Surrey Hospital were audited to determine the percentage of children who were prescribed adequate pain management in accordance with guidance published by the Association of Paediatric Anaesthetists of Great Britain and Ireland. Three audit cycles were completed. Data were collected retrospectively through case note review. The results from the first cycle showed that only 47% of children were prescribed with a recommended analgesic regimen. Implementation of change included the development of a protocol for analgesic delivery, which was disseminated to the anaesthetic and dental teams. Full compliance with the audit standards was then demonstrated in the second and third cycles. This audit demonstrates the importance of multidisciplinary collaboration in order to provide high standards of care for children undergoing dental extractions under general anaesthesia. The protocol developed could be applied to other surgical day case procedures for children to improve the patient experience.

[Study on preanesthetic risk evaluation in dogs using the ASA-classification system in Germany]. / Deutschlandweite Studie zur präanästhetischen Risikoeinschätzung mithilfe der ASA-Klassifikation beim Hund.

OBJECTIVE: The aim of this study was to assess the accuracy of anesthetic risk evaluation in dogs by using the ASA-classification system (ASA = American Society of Anesthesiologists). In human medicine, several studies criticize ranking patients prior to anesthesia via the ASA-classification due to its subjectivity and substantial variance. This study intends to detect and analyze possible comparable effects when applying the ASA-classification system to dogs. MATERIAL AND METHODS: An online survey was conducted among small animal practitioners throughout Germany. Participants were asked to answer questions concerning their professional background. In addition, they received a questionnaire containing information on 15 selected patients. This included a brief introduction of the patient, the medical history, findings of the preanesthetic examination, the results of blood analysis and biochemistry as well as the reason for planned general anesthesia. Participants were asked to classify the patients according to the ASA-classification scheme. The results were analyzed using an independent t-test, univariate ANOVA and Fleiss' Kappa (κ). The level of significance was set at 5 %. RESULTS: Overall, only weak consistency of the assigned ASA-classes (κ = 0.33) was evident. Each of the 15 patients was ranked in at least 3 different ASA-classes and 4 patients received assignment to all 5 possible classes. No effect of gender or clinical experience of the veterinarian could be detected on ranking patients correctly. There was also no effect of how confident veterinarians felt in applying the ASA-classification system on the accuracy of evaluating these 15 patients. CONCLUSION AND CLINICAL RELEVANCE: This study provides further evidence for a certain subjectivity as well as considerable variance when applying the ASA-classification system to dogs. The ASA-classification system is a widespread tool for rapid and easy preanesthetic risk classification of a veterinary patient. Nevertheless, the inclusion of criteria of increased objectivity in the preanesthetic evaluation is warranted in order to obtain precise and reproducible data.

Neuroanesthesia Guidelines for Optimizing Transcranial Motor Evoked Potential Neuromonitoring During Deformity and Complex Spinal Surgery: A Delphi Consensus Study.

STUDY DESIGN: Expert opinion-modified Delphi study. OBJECTIVE: We used a modified Delphi approach to obtain consensus among leading spinal deformity surgeons and their neuroanesthesiology teams regarding optimal practices for obtaining reliable motor evoked potential (MEP) signals. SUMMARY OF BACKGROUND DATA: Intraoperative neurophysiological monitoring of transcranial MEPs provides the best method for assessing spinal cord integrity during complex spinal surgeries. MEPs are affected by pharmacological and physiological parameters. It is the responsibility of the spine surgeon and neuroanesthesia team to understand how they can best maintain high-quality MEP signals throughout surgery. Nevertheless, varying approaches to neuroanesthesia are seen in clinical practice. METHODS: We identified 19 international expert spinal deformity treatment teams. A modified Delphi process with two rounds of surveying was performed. Greater than 50% agreement on the final statements was considered "agreement"; >75% agreement was considered "consensus." RESULTS: Anesthesia regimens and protocols were obtained from the expert centers. There was a large amount of variability among centers. Two rounds of consensus surveying were performed, and all centers participated in both rounds of surveying. Consensus was obtained for 12 of 15 statements, and majority agreement was obtained for two of the remaining statements. Total intravenous anesthesia was identified as the preferred method of maintenance, with few centers allowing for low mean alveolar concentration of inhaled anesthetic. Most centers advocated for <150 µg/kg/min of propofol with titration to the lowest dose that maintains appropriate anesthesia depth based on awareness monitoring. Use of adjuvant intravenous anesthetics, including ketamine, low-dose dexmedetomidine, and lidocaine, may help to reduce propofol requirements without negatively effecting MEP signals. CONCLUSION: Spine surgeons and neuroanesthesia teams should be familiar with methods for optimizing MEPs during deformity and complex spinal cases. Although variability in practices exists, there is consensus among international spinal deformity treatment centers regarding best practices. LEVEL OF EVIDENCE: 5.

[Coronavirus disease 2019 (COVID-19): update for anesthesiologists and intensivists March 2020]. / "Coronavirus disease 2019" (COVID-19): update für Anästhesisten und Intensivmediziner März 2020.

The current outbreak of coronavirus disease (COVID-19) has reached Germany. The majority of people infected present with mild disease, but there are severe cases that need intensive care. Unlike other acute infectious diseases progressing to sepsis, the severe courses of COVID19 seemingly show prolonged progression from onset of first symptoms to life-threatening deterioration of (primarily) lung function. Diagnosis relies on PCR using specimens from the respiratory tract. Severe ARDS reflects the hallmark of a critical course of the disease. Preventing nosocomial infections (primarily by correct use of personal protective equipment) and maintenance of hospitals' operational capability are of utmost importance. Departments of Anaesthesia, Intensive Care and emergency medicine will envisage major challenges.

2020 AAHA Anesthesia and Monitoring Guidelines for Dogs and Cats.

Risk for complications and even death is inherent to anesthesia. However, the use of guidelines, checklists, and training can decrease the risk of anesthesia-related adverse events. These tools should be used not only during the time the patient is unconscious but also before and after this phase. The framework for safe anesthesia delivered as a continuum of care from home to hospital and back to home is presented in these guidelines. The critical importance of client communication and staff training have been highlighted. The role of perioperative analgesia, anxiolytics, and proper handling of fractious/fearful/aggressive patients as components of anesthetic safety are stressed. Anesthesia equipment selection and care is detailed. The objective of these guidelines is to make the anesthesia period as safe as possible for dogs and cats while providing a practical framework for delivering anesthesia care. To meet this goal, tables, algorithms, figures, and "tip" boxes with critical information are included in the manuscript and an in-depth online resource center is available at aaha.org/anesthesia.

Prospective, Randomized Comparison of the i-gel and the Self-Pressurized air-Q Intubating Laryngeal Airway in Elderly Anesthetized Patients.

BACKGROUND: Age-related changes in upper airway anatomy may affect the overall performance of supraglottic airways significantly. The clinical performance of the i-gel and the self-pressurized air-Q intubating laryngeal airways with noninflatable cuffs for elderly populations remains unknown, unlike in children. Thus, we performed a prospective, randomized comparison of these 2 supraglottic airways in elderly patients undergoing general anesthesia. METHODS: We recruited 100 patients, 65-90 years of age, who were scheduled for elective surgery under general anesthesia with muscle relaxation. The enrolled patients were allocated to the i-gel or self-pressurized air-Q group. We assessed oropharyngeal leak pressure as the primary outcome and fiberoptic view after placement and fixation of the airway and at 10 minutes after the initial assessment. The fiberoptic view was scored using a 5-point scale as follows: vocal cords not visible; vocal cords and anterior epiglottis visible, >50% visual obstruction of epiglottis to vocal cords; vocal cords and anterior epiglottis visible, <50% visual obstruction of epiglottis to vocal cords; vocal cords and posterior epiglottis visible; and vocal cords visible. We also investigated success rate and ease of insertion, insertion time, and manipulations during insertion as insertion variables, complications during maintenance and emergence periods, and postoperative pharyngolaryngeal complications including sore throat, dysphagia, and dysphonia. RESULTS: After assessing for eligibility, 48 patients were allocated to each group. Oropharyngeal leak pressures were significantly higher in the i-gel group than in the self-pressurized air-Q group (P < .001) at the 2 measurement points. The raw mean difference at initial assessment and the median difference after 10 minutes were 5.5 cm H2O (95% confidence interval, 3.3-7.6 cm H2O) and 5.0 (95% confidence interval, 2.0-7.0 cm H2O), respectively. The initial scores of fiberoptic view were similar in the 2 groups. However, the self-pressurized air-Q supraglottic airway provided a significantly improved fiberoptic view at 10 minutes after initial assessment (P = .030). We found no statistically significant differences in insertion variables and complications between the 2 groups. CONCLUSIONS: The i-gel provided better sealing function than the self-pressurized air-Q supraglottic airway according to the high oropharyngeal leak pressures in elderly patients during general anesthesia. The self-pressurized air-Q supraglottic airway had improved fiberoptic views in elderly patients during general anesthesia.

American Society for Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on the Role of Neuromonitoring in Perioperative Outcomes: Electroencephalography.

Electroencephalographic (EEG) monitoring to indicate brain state during anesthesia has become widely available. It remains unclear whether EEG-guided anesthesia influences perioperative outcomes. The sixth Perioperative Quality Initiative (POQI-6) brought together an international team of multidisciplinary experts from anesthesiology, biomedical engineering, neurology, and surgery to review the current literature and to develop consensus recommendations on the utility of EEG monitoring during anesthesia. We retrieved a total of 1023 articles addressing the use of EEG monitoring during anesthesia and conducted meta-analyses from 15 trials to determine the effect of EEG-guided anesthesia on the rate of unintentional awareness, postoperative delirium, neurocognitive disorder, and long-term mortality after surgery. After considering current evidence, the working group recommends that EEG monitoring should be considered as part of the vital organ monitors to guide anesthetic management. In addition, we encourage anesthesiologists to be knowledgeable in basic EEG interpretation, such as raw waveform, spectrogram, and processed indices, when using these devices. Current evidence suggests that EEG-guided anesthesia reduces the rate of awareness during total intravenous anesthesia and has similar efficacy in preventing awareness as compared with end-tidal anesthetic gas monitoring. There is, however, insufficient evidence to recommend the use of EEG monitoring for preventing postoperative delirium, neurocognitive disorder, or postoperative mortality.

Derivation and validation of an equation to determine the optimal ventilator setting in children undergoing intracranial revascularization surgery: A single-center retrospective study.

BACKGROUND: It can be difficult to determine the appropriate ventilator settings to maintain normocapnia in children undergoing general anesthesia for surgery for moyamoya disease, especially immediately following anesthesia induction. AIM: We conducted this study to attempt to derive an equation to predict the appropriate ventilator settings and subsequently validated the accuracy of the equation. METHODS: A retrospective study of 91 pediatric patients less than 18 years of age who underwent cerebral revascularization for moyamoya disease at our institution. Fifty-eight patients were used to derive the equation, and the subsequent 33 patients were used to validate the equation. We calculated the required respiratory rate to attain normocapnia based on the median of all values of the minute volume during normocapnia (estimated partial pressure of arterial carbon dioxide of 38-42 mm Hg) and the assumption that the tidal volume was 8 mL/kg body weight. We derived the regression equation from the derivation data set where the required respiratory rate to attain normocapnia was represented by age. We simplified the equation by rounding coefficients to the nearest integer. The level of agreement between the respiratory rate predicted from the equation and the actual required respiratory rate was assessed in the validation group using Bland-Altman analysis. RESULTS: The derived equation is tidal volume = 8 mL/kg body weight, respiratory rate = 24-age/min. Bland-Altman analysis in the validation group revealed that the mean bias between the predicted and actual respiratory rate was 0.29 (standard deviation, 3.67). The percentage of cases where the predicted rate was within ± 10% and ± 20% of the actual rate was 42.4% and 66.7%, respectively. CONCLUSIONS: We derived and validated a simple and easily applicable equation to predict the ventilator settings required to attain normocapnia during general anesthesia in children with moyamoya disease.

Drug challenge tests with general anesthetics: predictive value of skin tests

BACKGROUND: The study of perioperative drug reactions remains a major challenge for both diagnosis and therapy. The lack of a standard assessment of allergy to general anesthetics and of data establishing the true value of skin tests for most drugs used in induction and maintenance of anesthesia, as well as the lack of commercially available reagents for in vitro tests, renders the study of these reactions problematic. The aims of this study were to provide a diagnostic protocol for drug challenge testing with general anesthetics, to establish an etiological diagnosis that is as specific as possible, and to determine the predictive value of skin tests. METHODS: Twenty-nine patients with perioperative drug reactions were included in the study from November 2008 to December 2018. RESULTS: We confirmed the high negative predictive value of the tests (96%-100%) in the case of propofol, rocuronium, and fentanyl. To our knowledge, this is the first study to describe drug challenge testing with general anesthetics and, therefore, to establish the true negative predictive value of skin tests, which leads to a definitive diagnosis and safer surgery. CONCLUSIONS: After assessing risks and benefits and considering the importance of this group of drugs, we conclude that drug challenge testing with general anesthetics is necessary. We propose a protocol for perioperative drug reactions that enables us to make a highly accurate etiological diagnosis with minimum risk for the patient

ANTECEDENTES: La ausencia de estandarización del estudio de alergia a anestésicos generales y ausencia de verdaderos datos sobre el valor de las pruebas cutáneas en la mayoría de los fármacos empleados en anestesia general, así como la ausencia de reactivos disponibles comercialmente para poder realizar tests in vitro, continúa suponiendo un dilema para estudiar las reacciones perianestésicas. El objetivo de este estudio fue aportar un protocolo de pruebas de provocación con anestésicos generales para poder establecer un diagnóstico etiológico lo mas especifico posible, y determinar el valor predictivo de las pruebas cutáneas. MÉTODOS: Desde noviembre de 2008 a diciembre de 2018, fueron estudiados 29 pacientes con reacciones perioperatorias a medicamentos. RESULTADOS: Con este estudio, confirmamos el alto valor predictivo negativo (VPN) de las pruebas cutáneas (96-100%) en el caso del propofol, rocuronio y fentanilo. En nuestro conocimiento, este es el primer trabajo que describe pruebas de provocación con anestésicos generales, y en aportar el verdadero VPN de las pruebas cutáneas, lo que permite llegar a un diagnóstico más definitivo, y a una mayor seguridad en futuras cirugías. CONCLUSIONES: Valorando riesgos /beneficios y considerando la importancia de este grupo de medicamentos, concluimos que las pruebas de provocación controlada con anestésicos generales, son necesarias. Proponemos un protocolo diagnóstico de las reacciones perioperatorias por fármacos, que permita alcanzar un diagnóstico etiológico lo más certero posible, con el menor riesgo para el paciente