Preoperative characterization of baseline EEG recordings for risk stratification of post-anesthesia care unit delirium

Study objectiveDelirium in the post-anesthesia care unit (PACU-D) presents a serious condition with a high medical and socioeconomic impact. In particular, PACU-D is among common postoperative complications of elderly patients. As PACU-D may be associated with postoperative delirium, early detection of at-risk patients and strategies to prevent PACU-D are important. We characterized EEG baseline signatures of patients who developed PACU-D following surgery and general anesthesia and patients who did not.Design and settingWe conducted a post-hoc analysis of preoperative EEG recordings between patients with and without PACU-D, as indicated by positive bCAM scores post general anesthesia and surgery.Patients and measurementsPreoperative baseline EEG recordings from 89 patients were recorded at controlled eyes-open (focused wakefulness) and eyes-closed (relaxed wakefulness) conditions. We computed power spectral densities, permutation entropy, spectral entropy and spectral edge frequency to see if these parameters can reflect potential baseline EEG differences between PACU-D (31.5%) and noPACU-D (68.5%) patients. Wilcoxon's Rank Sum Test as well as AUC values were used to determine statistical significance.Main resultsBaseline EEG recordings showed significant differences between PACU-D and noPACU-D patients preoperatively. Compared to the noPACU-D group, PACU-D patients presented with lower power in higher frequencies during relaxed and focused wakefulness alike. These differences in power led to AUC values of 0.73 [0.59;0.85] (permutation entropy) and 0.72 [0.61;0.83] (spectral edge frequency) indicative of a “fair” performance to separate patients with and without PACU-D.ConclusionsThe baseline EEG of relaxed wakefulness as well as focused wakefulness may be used to assess the risk of developing PACU-D following surgery under general anesthesia. Moreover, routinely used monitoring parameters capture these differences as well, potentially allowing an easy transfer to clinical settings.Clinical trial number: NCT03775356     

The effect of magnesium sulfate on emergence agitation in children undergoing general anesthesia: A systematic review and meta-analysis

Study objectiveEmergence agitation (EA) is a common complication in pediatric patients after general anesthesia. The effectiveness of magnesium sulfate in decreasing the incidence of EA in children remains controversial. Therefore, a systematic review and meta-analysis was performed to assess the efficacy of magnesium sulfate in preventing EA in pediatric patients following general anesthesia.DesignSystematic review and meta-analysis.SettingPubMed, Embase, Web of Science, and Cochrane Library were searched to identify eligible randomized controlled trials from their respective database inception dates to June 30, 2021.PatientsPediatric patients (< 18 years old) undergoing general anesthesia.InterventionsIntravenous administration of magnesium sulfate.MeasurementsThe primary outcome of the meta-analysis was EA incidence. The risk of bias of the included studies was evaluated using the revised Cochrane risk of bias tool for randomized trials (RoB 2.0). Grading of Recommendations, Assessment, Development, and Evaluation was applied to assess the level of certainty.Main resultsEight studies with 635 participants were identified. The forest plot revealed no significant difference in the incidence of EA between patients treated with magnesium sulfate and the control group (risk ratio = 0.69, 95% confidence interval [0.44, 1.07]; P = 0.10, I² = 74%, moderate level of certainty). Additionally, magnesium sulfate did not reduce postoperative pediatric anesthesia emergence delirium scores but prolonged the emergence time. No significant differences were observed in postoperative complications (nausea, vomiting, laryngospasm, breath-holding, coughing, oxygen desaturation, and cardiac arrhythmias).ConclusionsAdministration of magnesium sulfate during general anesthesia did not affect the occurrence of EA in pediatric patients. However, magnesium sulfate can prolong the emergence time without adverse effects.PROSPERO registration number: CRD42021252924.     

Delirium do despertar após anestesia com sevoflurano em adultos: estudo observacional prospectivo

Background and objectivesEmergence delirium after general anesthesia with sevoflurane has not been frequently reported in adults compared to children. This study aimed to determine the incidence of emergence delirium in adult patients who had anesthesia with sevoflurane as the volatile agent and the probable risk factors associated with its occurrence.Design and methodsA prospective observational study was conducted in adult patients who had non‐neurological procedures and no existing neurological or psychiatric conditions, under general anesthesia. Demographic data such as age, gender, ethnicity and clinical data including ASA physical status, surgical status, intubation attempts, duration of surgery, intraoperative hypotension, drugs used, postoperative pain, rescue analgesia and presence of catheters were recorded. Emergence delirium intensity was measured using the Nursing Delirium Scale (NuDESC).ResultsThe incidence of emergence delirium was 11.8%. The factors significantly associated with emergence delirium included elderly age (>65) (p = 0.04), emergency surgery (p = 0.04), African ethnicity (p = 0.01), longer duration of surgery (p = 0.007) and number of intubation attempts (p = 0.001). Factors such as gender, alcohol and illicit drug use, and surgical specialty did not influence the occurrence of emergence delirium.ConclusionsThe incidence of emergence delirium in adults after general anesthesia using sevoflurane is significant and has not been adequately reported. Modifiable risk factors need to be addressed to further reduce its incidence.     

Sevoflurane requirements during electroencephalogram (EEG)-guided vs standard anesthesia Care in Children: A randomized controlled trial

Study ObjectivesIntra-operative electroencephalographic (EEG) monitoring utilizing the spectrogram allows visualization of children's brain response during anesthesia and may complement routine cardiorespiratory monitoring to facilitate titration of anesthetic doses. We aimed to determine if EEG-guided anesthesia will result in lower sevoflurane requirements, lower incidence of burst suppression and improved emergence characteristics in children undergoing routine general anesthesia, compared to standard care.DesignRandomized controlled trial.SettingTertiary pediatric hospital.Patients200 children aged 1 to 6 years, ASA 1 or 2, undergoing routine sevoflurane anesthesia for minor surgery lasting 30 to 240 min.InterventionsChildren were randomized to either EEG-guided anesthesia (EEG-G) or standard care (SC). EEG-G group had sevoflurane titrated to maintain continuous slow/delta oscillations on the raw EEG and spectrogram, aiming to avoid burst suppression and, as far as possible, maintain a patient state index (PSI) between 25 and50. SC group received standard anesthesia care and the anesthesia teams were blinded to EEG waveforms.MeasurementsThe primary outcomes were the average end-tidal sevoflurane concentration during induction and maintenance of anesthesia. Secondary outcomes include incidence and duration of intra-operative burst suppression and Pediatric Anesthesia Emergence Delirium (PAED) scores.ResultsThe EEG-G group received lower end-tidal sevoflurane concentrations during induction [4.80% vs 5.67%, −0.88% (−1.45, −0.31) p = 0.003] and maintenance of anesthesia [2.23% vs 2.38%, −0.15% (−0.25, −0.05) p = 0.005], and had a lower incidence of burst suppression [3.1% vs 10.9%, p = 0.044] compared to the SC group. PAED scores were similar between groups. Children <2 years old required higher average end-tidal sevoflurane concentrations, regardless of group.ConclusionsEEG-guided anesthesia care reduces sevoflurane requirements in children undergoing general anesthesia, possibly lowering the incidence of burst suppression, without altering emergence characteristics. EEG monitoring allows direct visualization of brain responses in real time and allows clearer appreciation of varying sevoflurane requirements in children of different ages.     

Abdominal relaxation during emergence from general anesthesia with propofol and remifentanil

Study ObjectiveTo characterize respiratory dynamics during emergence from propofol-remifentanil anesthesia using noninvasive respiratory inductance plethysmography (RIP).DesignObservational pilot study.SettingOperating room in a university-affiliated teaching hospital.Patients50 ASA physical status 1, 2, and 3 patients scheduled for microdirect laryngoscopy or bronchoscopy using total intravenous anesthesia (TIVA) with high-frequency jet ventilation.InterventionsPatients were fitted with plethysmography bands around the chest and abdomen prior to induction. Following completion of surgery in patients undergoing brief airway procedures using propofol-remifentanil general anesthesia, the anesthetic infusions were stopped and ventilation suspended until resumption of spontaneous ventilation or desaturation below 90%. During this period of apnea, abdominal and thoracic girth was assessed with noninvasive RIP.MeasurementsCross-sectional area of the thorax and abdomen during emergence were measured.Main ResultsUseful data were obtained from 41 patients, with stable apnea lasting 404 ± 193.1 seconds; of these, 34 exhibited a slow and significant decrease in abdominal girth over a period of 267.8 ± 128.5 seconds. Resumption of spontaneous ventilation generally coincided with the end of this abdominal relaxation.ConclusionSlow expiration is the initial step in the resumption of spontaneous ventilation during apnea induced with TIVA using propofol-remifentanil.     

Depth of sedation using Cerebral State Index in infants undergoing spinal anesthesia

Background: Infants are noted to frequently sleep during spinal anesthesia, with a concomitant fall in Bispectral Index. However, there are suggestions that EEG derived anesthesia depth monitors have inferior performance in infants. The aim of this study was to quantify the degree of sedation during spinal anesthesia in infants using another EEG derived measure of anesthesia effect – the Cerebral State Index (CSI). Methods: Twelve infants, <52 weeks postconceptual menstrual age, scheduled for bilateral inguinal hernia repair under spinal anesthesia were enrolled. Patients received a standard anesthetic protocol with a subarachnoid dose of 1 mg·kg^?1 of levobupivacaine 0.5%. No premedication, sedatives, opioids or anticholinergics were administrated during the perioperative period and patients were left undisturbed during the surgical time, without tactile stimulation or loud auditory stimuli. CSI score (0–100) and bust suppression (BS) (0–100%) were continuously recorded during the surgical time and then statistically re‐evaluated. Results: In all patients the CSI fell during the procedure and there were significant levels of BS recorded by the CSI monitor. The BS occurred between 12 and 34 min after spinal anesthesia with the peak being at 30 min and mean onset time being 15 (2.6) min after spinal block. A statistical significant difference was found between the lowest mean CSI as well as the highest BS if compared with their baseline values. A negative correlation was found between CSI and BS. Conclusions: The degree of burst suppression detected by the CSI in our study supports the hypothesis that infants may have discontinuous patterns of EEG during spinal anesthesia similar to those seen during emergence from general anesthesia. Moreover, the limitations in the application of the adult algorithms to infant EEG may lead to an overestimation of the degree of sedation.     

Median effective concentration of remifentanil in target controlled infusion for smooth tracheal extubation during emergence from general anesthesia in elderly patients

Study objectiveTo determine the median effective concentration (EC₅₀) of remifentanil during targeted-controlled infusion for smooth tracheal extubation during emergence from total intravenous anesthesia in elderly patients.DesignProspective, Dixon up-and-down method.SettingPostoperative emergence.PatientsTwenty-four American Society of Anesthesiologists grade I-II female elderly patients undergoing elective jaw cyst surgery.InterventionsThe EC₅₀ of remifentanil for smooth emergence was calculated by the Dixon up-and-down method.MeasurementsThe EC₅₀ and 95% confidence intervals were analyzed by probit analysis using logistic regression. Vital signs (mean arterial pressure, heart rate, oxygen saturation, and end-tidal carbon dioxide partial pressure), postanesthesia recovery score, visual analogue pain scale, and adverse effects were monitored. Mean arterial pressure and heart rate were compared between patients with smooth extubation vs those with failed smooth extubation.Main resultsThe Dixon up-and-down method showed that the EC₅₀ of remifentanil for smooth tracheal extubation during emergency from anesthesia was 0.94 ng/mL in female elderly patients. The probit analysis showed that the EC₅₀ of remifentanil was 0.99 ng/mL (95% confidence interval, 0.52-1.51 ng/mL). Heart rate and mean arterial pressure were significantly lower in patients with smooth extubation as compared with those with failed smooth extubation at 0 minute (at extubation) as well as 1 and 5 minutes after extubation (P< .05).ConclusionsTarget infusion of remifentanil at 0.94 ng/mL could effectively inhibit tracheal extubation–related cough response and cardiovascular responses in 50% of the female elderly patients without delaying recovery from anesthesia, which could ensure smooth tracheal extubation during emergence from anesthesia.     

Anesthetic‐specific electroencephalographic patterns during emergence from sevoflurane and isoflurane in infants and children

Background: Devices that monitor the depth of anesthesia are increasingly used to titrate sedation and avoid awareness during anesthesia. Many of these monitors are based upon electroencephalography (EEG) collected from large adult reference populations and not pediatric populations (Anesthesiology, 86, 1997, 836; Journal of Anaesthesia, 92, 2004, 393; Anesthesiology, 99, 2003, 34). We hypothesized that EEG patterns in children would be different from those previously reported in adults and that they would show anesthetic‐specific characteristics. Methods: This prospective observational study was approved by the Institutional Review Board, and informed written consent was obtained. Patients were randomized to receive maintenance anesthesia with isoflurane or sevoflurane. EEG data collection included at least 10 min at steady‐state maintenance anesthesia. The EEG was recorded continuously through emergence until after extubation. A mixed model procedure was performed on global and regional power by pooled data analysis and by analyzing each anesthetic group separately. Statistical significance was defined as P < 0.05. Results: Thirty‐seven children completed the study (ages 22 days–3.6 years). Isoflurane and sevoflurane had different effects on global and regional EEG power during emergence from anesthesia, and frontal predominance patterns were significantly different between these two anesthetic agents. Conclusions: The principal finding of the present study was that there are anesthetic‐specific and concentration‐dependent EEG effects in children. Depth‐of‐anesthesia monitors that utilize algorithms based on the EEGs of adult reference populations therefore may not be appropriate for use in children.     

Predictors of desaturation in the postoperative anesthesia care unit: an observational study

Study ObjectiveTo evaluate predictors of desaturation and to identify practice for patient transport following general anesthesia.DesignObservational quality assurance study.SettingPostanesthesia Care Unit (PACU) of a university-affiliated, tertiary-care hospital.PatientsAll adult postsurgical patients who received general anesthesia and who were admitted to the PACU.MeasurementsPatients were observed over a three-month study period during transfer to the PACU with or without oxygen supplementation. Sixteen variables related to patient, surgery, and anesthesia were recorded.ResultsThe study recorded a total of 502 PACU admissions. The practice pattern showed that 57% of patients were transferred without oxygen and 19% of the entire sample had an initial oxygen desaturation of less than 90% on arrival to the PACU. Only 0.8% of patients experienced oxygen desaturation when they were transferred with oxygen supplementation. After logistic regression analysis, the most significant predictor of desaturation was transport without oxygen.ConclusionsThe majority of anesthesiologists did not use supplemental oxygen for patient transfer. As a result, a higher incidence of postoperative desaturation was noted in their patients. Significant predictors of desaturation after general anesthesia included patients' sedation score, low respiratory rate, and transport without oxygen. The use of oxygen almost completely prevented desaturation during transport.     

Postanesthesia emergence in patients with post-traumatic stress disorder

Study objectiveRecovery from anesthesia may be complicated with development of severe panic symptoms and anxiety. Preexisting anxiety disorder has been reported as a risk factor for development of these symptoms. We aimed to examine the frequency of emergence delirium (EDL) among veterans diagnosed with posttraumatic stress disorders (PTSDs).DesignRetrospective cohort.SettingPostoperative recovery area.PatientsPerioperative information of 1763 consecutive patients who underwent a surgical procedure requiring general anesthesia were collected. The patients were grouped on the basis of previous diagnosis of PTSD. A total of 317 patients were identified with a positive history of PTSD and were compared to 1446 patients without such a history for the occurrence of EDL in the postanesthesia care unit (PACU) as the primary endpoint.MeasurementsDuration of stay in PACU in minutes and the frequency of hospital admission were the secondary endpoints. Multivariate binary logistic regression analysis was performed to identify the predictors of EDL among the veteran population.Main resultsEmergence delirium was reported in 37 cases (2.1%) after general anesthesia. Fifteen (4.7%) of 317 patients with PTSD and 22 (1.5%) of 1446 patients without history of PTSD demonstrated symptoms related to EDL in the PACU (P = .002). After propensity matching, there were 8 patients with EDL in the PTSD group whereas there were only 2 patients with EDL among controls. Posttraumatic stress disorder was also an independent predictor of EDL in multivariate analysis with an odds ratio of 6.66 and a 95% confidence interval of 2.04 to 21.72 (P = .002).ConclusionsPosttraumatic stress disorder independently predicted the frequency of EDL even after correcting for preexisting depression and anxiety disorders. A relatively longer duration of PACU stay in PTSD patients may reflect raised awareness of the health care workers about this debilitating mental disorder.     

Association of electroencephalogram trajectories during emergence from anaesthesia with delirium in the postanaesthesia care unit: an early sign of postoperative complications

Background

Postoperative delirium is associated with an increased risk of morbidity and mortality, especially in the elderly. Delirium in the postanaesthesia care unit (PACU) could predict adverse clinical outcomes.

Narcotrend,bispectral index,and classical electroencephalogram variables during emergence from propofol/remifentanil anesthesia

The aim of this study was to investigate modern and classical electroencephalographic (EEG) variables in response to remifentanil and propofol infusions. We hypothesized that modern EEG variables may indicate the effects of propofol but not of remifentanil. Twenty-five patients were included in the study after the end of elective spine surgery without any surgical stimulation. Baseline values were defined with remifentanil 0.3 microg. kg(-1). min(-1) and target-controlled infusion of propofol 3.0 microg/mL. EEG changes were evaluated 1, 3, 5, 7, and 9 min after the stop of remifentanil infusion, followed by a step-by-step reduction (0.2 microg/mL) every 3 min of target-controlled infusion propofol. Narcotrend (NT; classifying EEG stages from awake to deep anesthesia), bispectral index (BIS), EEG spectral frequency bands (%), 50% (Median) and 95% percentiles (spectral edge frequency), mean arterial blood pressure, heart rate, and oxygen saturation were detected at every time point. The end of remifentanil application resulted in significant increases in %alpha, spectral edge frequency, mean arterial blood pressure, and %theta and decreases in %delta (P < 0.05). NT, BIS, Median, heart rate, and oxygen saturation were unchanged. Decreases in propofol concentration were associated with statistically significant increases in NT and BIS (P < 0.05). Thus, the sedative-hypnotic component of propofol could be estimated by modern EEG variables (NT and BIS), whereas the analgesic component provided by remifentanil was not indicated. However, during conditions without surgical stimulation, neither NT nor BIS provided an adequate assessment of the depth of anesthesia when a remifentanil infusion was used. IMPLICATIONS: We investigated modern and classical electroencephalographic (EEG) variables during emergence from propofol/remifentanil anesthesia. Modern EEG variables indicate changes of infusion in propofol, but not in remifentanil. Thus, modern EEG variables did not provide an adequate assessment of depth of anesthesia when remifentanil was used.     

Human auditory steady-state response during general anesthesia

The 40-Hz auditory steady-state evoked response (ASSR) is a sinusoidal electrical response of the brain to periodically presented auditory stimuli. It was recorded during anesthesia in 10 elective surgical patients to evaluate its usefulness as a measure of the level of consciousness. The anesthetic agents used were thiopental, fentanyl, and isoflurane with or without nitrous oxide. Recordings were carried out during the period before induction and during induction, surgical anesthesia, emergence, and recovery from anesthesia. The level of consciousness was measured with an auditory stimulus detection task. The electroencephalogram (EEG) was also recorded for comparison with the ASSR. The following indices were analyzed: total EEG power, relative power in the beta, alpha, theta, and delta frequency bands, and the median and spectral edge frequency. The amplitude of the ASSR was reduced significantly at the end of the induction period and decreased below noise levels during surgical anesthesia. It increased significantly during emergence and recovery. The amplitude during recovery remained significantly smaller than the preinduction values. The changes of the ASSR paralleled those of the level of consciousness. The EEG measurements were distorted by the presence of muscle artifacts that were prominent during emergence and recovery. The amplitude of the ASSR appears to provide a more reliable indicator of the level of consciousness than the EEG.     

A prospective study of bispectral index scoring in mentally retarded patients receiving general anesthesia

Study ObjectiveTo determine whether degree of mental retardation (MR) affects bispectral index scale (BIS) scores during general anesthesia.DesignProspective clinical study.SettingUniversity Hospital.Patients80 ASA physical status I, II and III patients with varying degrees of MR, undergoing dental rehabilitation.InterventionsPatients were grouped into mild, moderate, severe or profound degrees of MR, by an independent registered research nurse according to criteria by the American Psychiatric Association.MeasurementsAll patients were given a standard sevoflurane in oxygen anesthetic with ASA standard monitoring. A research assistant who was blinded to study group assignment recorded the BIS scores continuously on a computer and compared the scores at the following time points: awake, induction of anesthesia, intravenous catheter placement, tracheal intubation, start of surgery, end of surgery, awakening to commands, and tracheal extubation.Main ResultsNo significant differences in BIS scores existed among the study groups at any time point. No significant difference in slope of induction of anesthesia was noted among the study groups. However, the slope of emergence from anesthesia leading to tracheal extubation showed a significantly longer emergence time in the higher MR groups.ConclusionMR does not affect BIS values during general anesthesia.     

Anesthetic technique for cesarean delivery and neonatal acid–base status: a retrospective database analysis

IntroductionA previous meta-analysis reported lower umbilical artery pH with spinal anesthesia for cesarean delivery compared to general or epidural anesthesia. Ephedrine was used in the majority of studies. The objective of this study was to evaluate the effect of anesthetic technique on neonatal acid–base status now that phenylephrine has replaced ephedrine in our institution.MethodsWe retrospectively reviewed our database to identify patients who underwent cesarean delivery and had umbilical artery pH available. We decided a priori to test separately cases where cesarean delivery was performed emergently (category I and II) or non-emergently (category III and IV). Multivariable models were constructed to detect significant predictors of lower umbilical artery pH.ResultsOne thousand sixty-four cases were included (647 emergent, 417 non emergent). In emergent cesarean delivery, anesthesia type was a significant predictor of lower umbilical artery pH (P <0.0001) with the pairwise comparisons showing lower neonatal umbilical artery pH [mean (95% CI)] with general anesthesia [7.16 (7.13, 7.19)] compared with spinal anesthesia [7.24 (7.22, 7.25)] and epidural anesthesia [7.23 (7.21, 7.24)], with no difference between spinal and epidural anesthesia. When excluding cases where general anesthesia was chosen due to insufficient time to place a neuraxial block or dose an existing epidural catheter, anesthesia type was not a predictor of lower umbilical artery pH. Anesthetic technique was not a predictor of lower umbilical artery pH in non-emergent cases.ConclusionsSpinal anesthesia was not associated with lower umbilical artery pH compared to other types of anesthesia. This might be due to the use of phenylephrine in our practice.     

Is Neuraxial Anesthesia Safe in Patients Undergoing Surgery for Treatment of Periprosthetic Joint Infection?

BackgroundThere is concern that neuraxial anesthesia in patients undergoing surgery for treatment of a periprosthetic joint infection (PJI) may increase the risk of having a central nervous system infection develop. However, the available data on this topic are limited and contradictory.Questions/purposesWe wished to determine whether neuraxial anesthesia (1) is associated with central nervous system infections in patients undergoing surgery for a PJI, and (2) increases the likelihood of systemic infection in these patients.MethodsAll 539 patients who received neuraxial or general anesthesia during 1499 surgeries for PJI from October 2000 to May 2013 were included in this study; of these, 51% (n = 764) of the surgeries were performed in 134 patients receiving neuraxial anesthesia and 49% were performed in 143 patients receiving general anesthesia. Two hundred sixty-two patients received general and neuraxial anesthesia during different surgeries. We used the International Classification of Diseases, 9^th Revision codes and the medical records to identify patients who had an intraspinal abscess or meningitis develop after surgery for a PJI. Multivariate analysis was used to assess the effect of type of anesthesia (neuraxial versus general) on postoperative complications.ResultsThere were no cases of meningitis, but one epidural abscess developed in a patient after neuraxial anesthesia. This patient underwent six revision surgeries during a 42-day period. Patients who received neuraxial anesthesia had lower odds of systemic infections (4% versus 12%; odds ratio, 0.35; 95% CI, 023–054; p < 0.001).ConclusionsCentral nervous system infections after neuraxial anesthesia in patients with a PJI appear to be exceedingly rare. Based on the findings of this study, it may be time for the anesthesiology community to reevaluate the risk of sepsis as a relative contraindication to the use of neuraxial anesthesia.

Level of Evidence

Level III, therapeutic study.     

Fatores de risco associados a delírio no despertar da anestesia em crianças submetidas à cirurgia ambulatorial

IntroductionAnesthesia emergence delirium is a self‐limiting clinical phenomenon very common in children. Although pathophysiology is still uncertain, some factors seem to be involved, such as rapid awakening in an unknown environment, agitation during anesthetic induction, preoperative anxiety, environmental disorders, use of preanesthetic medication, use of inhalational anesthetics, and postoperative pain.ObjectiveTo determine the prevalence and risk factors associated with anesthesia emergence delirium in children undergoing outpatient surgery.MethodsA prospective observational study was carried out with 100 children aged 2 to 10 years, who underwent surgery on an outpatient basis. The study variables were: anesthesia emergence delirium and the associated risk factors (preoperative anxiety, child impulsive behavior, use of pre‐anesthetic medication, traumatic induction, type of anesthesia, and postoperative pain). Multivariate Poisson's logistic regression was used to analyze the possible explanatory variables, where the prevalence ratios were estimated with the respective 95% confidence intervals, considering a significance level of 5%.ResultsDelirium and pain were observed in 27% and 20% of children, respectively. Only postoperative pain after Poisson's regression, was shown to be associated with anesthesia emergence delirium, with a prevalence ratio of 3.91 (p < 0.000).ConclusionThe present study showed 27% prevalence of anesthesia emergence delirium in the study population. The incidence of anesthesia emergence delirium was higher in children who had postoperative pain.     

Quantitative analysis of electroencephalographic (EEG) activity during sevoflurane anesthesia]

The change in electroencephalographic (EEG) activity during sevoflurane anesthesia was quantitatively evaluated by using zero-crossing analysis in 10 adult patients. The deceleration of EEG activity was significant and dose-dependent. Such change was not significantly different among the regions. Burst suppression appeared at 2-2.5 MAC in all patients. The significant decrease in both alpha and beta activities and the significant increase in delta activity disappeared with 1% or less of sevoflurane. Toward the emergence from anesthesia, EEG activity accelerated and there was no significant difference in its activity between the emergence period and control period. The results demonstrated that the effect of sevoflurane on EEG activity is similar to that of other inhalation anesthetics, but the difference among anesthetics should be clarified in a further study.     

Perioperative cardiac arrest and mortality in trauma patients: A systematic review of observational studies

Study objectiveFactors that influence the occurrence of perioperative cardiac arrest (CA) and its outcomes in trauma patients are not well known. The novelty of our study lies in the performance of a systematic review conducted worldwide on the occurrence of perioperative CA and/or mortality in trauma patients.DesignA systematic review was performed to identify observational studies that reported the occurrence of CA and/or mortality due to trauma and CA and/or mortality rates in trauma patients up to 24 h postoperatively. We searched the MEDLINE, EMBASE, LILACS and SciELO databases through January 29, 2020.SettingPerioperative period.MeasurementsThe primary outcomes evaluated were data on the epidemiology of perioperative CA and/or mortality in trauma patients.Main resultsNine studies were selected, with the first study being published in 1994 and the most recent being published in 2019. Trauma was an important factor in perioperative CA and mortality, with rates of 168 and 74 per 10,000 anesthetic procedures, respectively. The studies reported a higher proportion of perioperative CA and mortality in trauma patients who were males, young adults and adults, patients with American Society of Anesthesiologists (ASA) physical status ≥ III, patients undergoing general anesthesia, and in abdominal or neurological surgeries. Uncontrolled hemorrhage was the main cause of perioperative CA and mortality after trauma. Survival rates after perioperative CA were low.ConclusionsTrauma is an important factor in perioperative CA and mortality, especially in young adult and adult males and in patients classified as having an ASA physical status ≥ III mainly due to uncontrollable bleeding after blunt and perforating injuries. Trauma is a global public health problem and has a strong impact on perioperative morbidity and mortality.