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Intensive Care Medicine Dec 2021Post-cardiac arrest brain injury (PCABI) is caused by initial ischaemia and subsequent reperfusion of the brain following resuscitation. In those who are admitted to... (Review)
Review
Post-cardiac arrest brain injury (PCABI) is caused by initial ischaemia and subsequent reperfusion of the brain following resuscitation. In those who are admitted to intensive care unit after cardiac arrest, PCABI manifests as coma, and is the main cause of mortality and long-term disability. This review describes the mechanisms of PCABI, its treatment options, its outcomes, and the suggested strategies for outcome prediction.
Topics: Brain Injuries; Cardiopulmonary Resuscitation; Coma; Heart Arrest; Humans; Prognosis
PubMed: 34705079
DOI: 10.1007/s00134-021-06548-2 -
Journal of the American College of... Nov 2019Syncope is a commonly encountered and challenging problem in medical practice. Presentations are variable, and the causal mechanism often remains elusive even after... (Comparative Study)
Comparative Study Review
Syncope is a commonly encountered and challenging problem in medical practice. Presentations are variable, and the causal mechanism often remains elusive even after extensive (and often expensive) evaluation. Clinical practice guidelines have been developed to help guide the multidisciplinary approach necessary to diagnose and manage the broad spectrum of patients presenting with syncope. The American College of Cardiology/American Heart Association, in collaboration with the Heart Rhythm Society, published its first syncope guidelines in 2017. The European Society of Cardiology released the fourth iteration of its syncope guidelines in 2018. This review highlights the differences and congruencies between the 2 sets of recommendations, their implications for clinical practice, the remaining gaps in understanding, and areas of future research.
Topics: American Heart Association; Humans; Practice Guidelines as Topic; Societies, Medical; Syncope; United States
PubMed: 31699282
DOI: 10.1016/j.jacc.2019.09.012 -
JAMA Dec 2023Tracheal intubation is recommended for coma patients and those with severe brain injury, but its use in patients with decreased levels of consciousness from acute...
IMPORTANCE
Tracheal intubation is recommended for coma patients and those with severe brain injury, but its use in patients with decreased levels of consciousness from acute poisoning is uncertain.
OBJECTIVE
To determine the effect of intubation withholding vs routine practice on clinical outcomes of comatose patients with acute poisoning and a Glasgow Coma Scale score less than 9.
DESIGN, SETTING, AND PARTICIPANTS
This was a multicenter, randomized trial conducted in 20 emergency departments and 1 intensive care unit (ICU) that included comatose patients with suspected acute poisoning and a Glasgow Coma Scale score less than 9 in France between May 16, 2021, and April 12, 2023, and followed up until May 12, 2023.
INTERVENTION
Patients were randomized to undergo conservative airway strategy of intubation withholding vs routine practice.
MAIN OUTCOMES AND MEASURES
The primary outcome was a hierarchical composite end point of in-hospital death, length of ICU stay, and length of hospital stay. Key secondary outcomes included adverse events resulting from intubation as well as pneumonia within 48 hours.
RESULTS
Among the 225 included patients (mean age, 33 years; 38% female), 116 were in the intervention group and 109 in the control group, with respective proportions of intubations of 16% and 58%. No patients died during the in-hospital stay. There was a significant clinical benefit for the primary end point in the intervention group, with a win ratio of 1.85 (95% CI, 1.33 to 2.58). In the intervention group, there was a lower proportion with any adverse event (6% vs 14.7%; absolute risk difference, 8.6% [95% CI, -16.6% to -0.7%]) compared with the control group, and pneumonia occurred in 8 (6.9%) and 16 (14.7%) patients, respectively (absolute risk difference, -7.8% [95% CI, -15.9% to 0.3%]).
CONCLUSIONS AND RELEVANCE
Among comatose patients with suspected acute poisoning, a conservative strategy of withholding intubation was associated with a greater clinical benefit for the composite end point of in-hospital death, length of ICU stay, and length of hospital stay.
TRIAL REGISTRATION
ClinicalTrials.gov Identifier: NCT04653597.
Topics: Humans; Female; Adult; Male; Coma; Hospital Mortality; Intubation, Intratracheal; Emergency Service, Hospital; Pneumonia
PubMed: 38019968
DOI: 10.1001/jama.2023.24391 -
Kardiologia Polska 2021Syncope is a frequent event in the general population. Approximately 1%-2% of all emergency department admissions are due to syncope and at least one-third of all people... (Review)
Review
Syncope is a frequent event in the general population. Approximately 1%-2% of all emergency department admissions are due to syncope and at least one-third of all people experience fainting in their life. Although consequences of cardiac syncope are generally feared, non-cardiac syncope is much more common and may be associated with severe injuries and quality-of-life impairment, particularly in older adults. Various diagnostic and therapeutic strategies have been created and implemented over decades, leading to significant improvements in diagnostic accuracy and treatment effectiveness. In recent years, diagnosis and treatment have further evolved according to an innovative approach focused on the hemodynamic mechanism underlying syncope, based upon the assumption that knowledge of the syncope mechanism is a prerequisite for effective syncope prevention and treatment. Therefore, a new classification of syncope has been proposed, which defines two main syncope phenotypes with different predominant mechanisms: the hypotensive phenotype, where hypotension or vasodepression prevails, and the bradycardic phenotype, where cardioinhibition prevails. Identification of syncope phenotype - bradycardic or hypotensive/vasodepressive - represents the first step towards personalized management of syncope, characterized by customized interventions for prevention. The present review aims to illustrate these new developments in the diagnosis and therapy of non-cardiac syncope within a mechanism-based perspective. Diagnosis and therapy of bradycardic and hypotensive phenotypes are discussed, with a focus on recent evidence.
Topics: Aged; Bradycardia; Hemodynamics; Humans; Hypotension; Syncope; Tilt-Table Test
PubMed: 34668180
DOI: 10.33963/KP.a2021.0138 -
Critical Care (London, England) Nov 2022Most of the patients who die after cardiac arrest do so because of hypoxic-ischemic brain injury (HIBI). Experimental evidence shows that temperature control targeted at... (Review)
Review
Most of the patients who die after cardiac arrest do so because of hypoxic-ischemic brain injury (HIBI). Experimental evidence shows that temperature control targeted at hypothermia mitigates HIBI. In 2002, one randomized trial and one quasi-randomized trial showed that temperature control targeted at 32-34 °C improved neurological outcome and mortality in patients who are comatose after cardiac arrest. However, following the publication of these trials, other studies have questioned the neuroprotective effects of hypothermia. In 2021, the largest study conducted so far on temperature control (the TTM-2 trial) including 1900 adults comatose after resuscitation showed no effect of temperature control targeted at 33 °C compared with normothermia or fever control. A systematic review of 32 trials published between 2001 and 2021 concluded that temperature control with a target of 32-34 °C compared with fever prevention did not result in an improvement in survival (RR 1.08; 95% CI 0.89-1.30) or favorable functional outcome (RR 1.21; 95% CI 0.91-1.61) at 90-180 days after resuscitation. There was substantial heterogeneity across the trials, and the certainty of the evidence was low. Based on these results, the International Liaison Committee on Resuscitation currently recommends monitoring core temperature and actively preventing fever (37.7 °C) for at least 72 h in patients who are comatose after resuscitation from cardiac arrest. Future studies are needed to identify potential patient subgroups who may benefit from temperature control aimed at hypothermia. There are no trials comparing normothermia or fever control with no temperature control after cardiac arrest.
Topics: Adult; Humans; Hypothermia, Induced; Coma; Hypothermia; Heart Arrest; Cardiopulmonary Resuscitation; Fever
PubMed: 36434649
DOI: 10.1186/s13054-022-04238-z -
Pediatric Emergency Care Sep 2020The aims of the study were to perform the first systematic review of pediatric syncope etiologies and to determine the most common diagnoses with credible intervals...
OBJECTIVES
The aims of the study were to perform the first systematic review of pediatric syncope etiologies and to determine the most common diagnoses with credible intervals (CredIs).
METHODS
Review was performed within Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and used Embase, Scopus, PubMed, and the Cochrane Controlled Trial databases. The following inclusion criteria for the articles were used: minimum of 10 patients, standard definition of syncope used, subjects who were 21 years or younger, and subjects who were either a consecutive retrospective group or a prospective group. No restrictions were made regarding language of the studies, but an English abstract was required. The following information was collected: purpose of the study, definition of syncope, number of patients, patient age range, inclusion/exclusion criteria, and etiologies of syncope.
RESULTS
Of the 500 articles initially identified, 11 studies met the inclusion criteria and were the basis for this review. Three thousand seven hundred patients were included, ranging in age from 3 months to 21 years. The most common etiologies identified were vasovagal (52.2%; 95% CredI, 50.6-53.9), postural orthostatic tachycardia syndrome (13.1%; 95% CredI, 12.1-14.2), and cardiac causes (4.0%; 95% CredI, 3.39-4.65). A total of 18.3% (95% CredI, 17.0-19.5) of patients were found to have syncope of unknown cause.
CONCLUSIONS
Syncope is a common pediatric complaint. Most cases seen are a result of benign causes, with only a small percentage because of serious medical conditions. In addition, most syncopal episodes in the pediatric population are diagnosed clinically or with minimally invasive testing, emphasizing the importance of a detailed history and physical examination.
Topics: Child; Diagnosis, Differential; Humans; Medical History Taking; Physical Examination; Syncope
PubMed: 32530839
DOI: 10.1097/PEC.0000000000002149 -
ELife May 2021Understanding how the brain recovers from unconsciousness can inform neurobiological theories of consciousness and guide clinical investigation. To address this... (Comparative Study)
Comparative Study
Understanding how the brain recovers from unconsciousness can inform neurobiological theories of consciousness and guide clinical investigation. To address this question, we conducted a multicenter study of 60 healthy humans, half of whom received general anesthesia for 3 hr and half of whom served as awake controls. We administered a battery of neurocognitive tests and recorded electroencephalography to assess cortical dynamics. We hypothesized that recovery of consciousness and cognition is an extended process, with differential recovery of cognitive functions that would commence with return of responsiveness and end with return of executive function, mediated by prefrontal cortex. We found that, just prior to the recovery of consciousness, frontal-parietal dynamics returned to baseline. Consistent with our hypothesis, cognitive reconstitution after anesthesia evolved over time. Contrary to our hypothesis, executive function returned first. Early engagement of prefrontal cortex in recovery of consciousness and cognition is consistent with global neuronal workspace theory.
Topics: Adult; Anesthesia Recovery Period; Anesthesia, General; Brain; Cognition; Consciousness; Electroencephalography; Female; Humans; Isoflurane; Male; Unconsciousness
PubMed: 33970101
DOI: 10.7554/eLife.59525 -
British Journal of Anaesthesia Jul 2022Remimazolam is a new rapid offset benzodiazepine used for procedural sedation and general anaesthesia. This study evaluated the efficacy and safety of i.v. bolus... (Randomized Controlled Trial)
Randomized Controlled Trial
Pharmacodynamic analysis of intravenous bolus remimazolam for loss of consciousness in patients undergoing general anaesthesia: a randomised, prospective, double-blind study.
BACKGROUND
Remimazolam is a new rapid offset benzodiazepine used for procedural sedation and general anaesthesia. This study evaluated the efficacy and safety of i.v. bolus remimazolam during induction of anaesthesia.
METHODS
A total of 120 patients undergoing general anaesthesia were randomly allocated into six dose groups (n=20) of i.v. bolus remimazolam (0.02-0.27 mg kg). Loss of consciousness, respiratory depression, patient state index (PSI), and haemodynamic variables were evaluated during anaesthetic induction. Parametric time-to-event models were used to identify the 50% effective dose (ED50)/95% effective dose (ED95) associated with loss of consciousness and respiratory depression. Non-linear mixed-effect models analysed the PSI and haemodynamic changes after i.v. bolus remimazolam.
RESULTS
Loss of consciousness and respiratory depression onset showed steep dose-responses with ED50/ED95 of 0.11/0.19 and 0.14/0.27 mg kg and Hill coefficients of 5.3 and 4.6, respectively. Older age was significantly associated with lower ED50/ED95 for both endpoints. ED50/ED95 and the Hill coefficient of PSI decline were 0.12/0.68 mg kg and 1.7, respectively. We propose optimal doses of 0.25-0.33, 0.19-0.25, and 0.14-0.19 mg kg in patients aged <40, 60-80, and >80 yr, respectively, based on the ED95 estimates for the corresponding age groups. The maximum percentage reduction of MAP was 27.8% and the ED50/ED95 were 0.14/2.60 mg kg. The effect of remimazolam on heart rate was insignificant.
CONCLUSIONS
The ED50/ED95s of i.v. bolus remimazolam were successfully estimated from the time to loss of consciousness and respiratory depression. No serious adverse events occurred within the range of tested doses.
CLINICAL TRIAL REGISTRATION
NCT04901871.
Topics: Anesthesia, General; Benzodiazepines; Dose-Response Relationship, Drug; Double-Blind Method; Humans; Hypnotics and Sedatives; Midazolam; Prospective Studies; Respiratory Insufficiency; Unconsciousness
PubMed: 35562226
DOI: 10.1016/j.bja.2022.02.040 -
General anesthesia globally synchronizes activity selectively in layer 5 cortical pyramidal neurons.Neuron Jun 2022General anesthetics induce loss of consciousness, a global change in behavior. However, a corresponding global change in activity in the context of defined cortical cell...
General anesthetics induce loss of consciousness, a global change in behavior. However, a corresponding global change in activity in the context of defined cortical cell types has not been identified. Here, we show that spontaneous activity of mouse layer 5 pyramidal neurons, but of no other cortical cell type, becomes consistently synchronized in vivo by different general anesthetics. This heightened neuronal synchrony is aperiodic, present across large distances, and absent in cortical neurons presynaptic to layer 5 pyramidal neurons. During the transition to and from anesthesia, changes in synchrony in layer 5 coincide with the loss and recovery of consciousness. Activity within both apical and basal dendrites is synchronous, but only basal dendrites' activity is temporally locked to somatic activity. Given that layer 5 is a major cortical output, our results suggest that brain-wide synchrony in layer 5 pyramidal neurons may contribute to the loss of consciousness during general anesthesia.
Topics: Anesthesia, General; Anesthetics, General; Animals; Dendrites; Mice; Pyramidal Cells; Unconsciousness
PubMed: 35452606
DOI: 10.1016/j.neuron.2022.03.032 -
British Journal of Anaesthesia Jun 2022Sedated patients have graded levels of consciousness and perceptual connection with the outside world. Disconnection is associated with widespread changes in the...
Sedated patients have graded levels of consciousness and perceptual connection with the outside world. Disconnection is associated with widespread changes in the electroencephalogram, whereas full unconsciousness is linked with decreased activity specifically in the deep midline regions of the brain. These findings can be interpreted within the predictive coding model of consciousness as differences in model generation vs discrepancy detection. Anaesthetists should be cognisant that apparently unresponsive patients might still have some ongoing partially disconnected consciousness activity.
Topics: Auditory Perception; Brain; Consciousness; Electroencephalography; Humans; Unconsciousness
PubMed: 35249703
DOI: 10.1016/j.bja.2022.02.001