Reducing the carbon footprint of general anaesthesia: a comparison of total intravenous anaesthesia vs. a mixed anaesthetic strategy in 47,157 adult patients.

Global warming is a major public health concern. Volatile anaesthetics are greenhouse gases that increase the carbon footprint of healthcare. Modelling studies indicate that total intravenous anaesthesia is less carbon intensive than volatile anaesthesia, with equivalent quality of care. In this observational study, we aimed to apply the findings of previous modelling studies to compare the carbon footprint per general anaesthetic of an exclusive TIVA strategy vs. a mixed TIVA-volatile strategy. This comparative retrospective study was conducted over 2 years in two French hospitals, one using total intravenous anaesthesia only and one using a mixed strategy including both intravenous and inhalation anaesthetic techniques. Based on pharmacy procurement records, the quantity of anaesthetic sedative drugs was converted to carbon dioxide equivalents. The primary outcome was the difference in carbon footprint of hypnotic drugs per intervention between the two strategies. From 1 January 2021 to 31 December 2022, 25,137 patients received general anaesthesia in the hospital using the total intravenous anaesthesia strategy and 22,020 in the hospital using the mixed strategy. The carbon dioxide equivalent footprint of hypnotic drugs per intervention in the hospital using the total intravenous anaesthesia strategy was 20 times lower than in the hospital using the mixed strategy (emissions of 2.42 kg vs. 48.85 kg carbon dioxide equivalent per intervention, respectively). The total intravenous anaesthesia strategy significantly reduces the carbon footprint of hypnotic drugs in general anaesthesia in adult patients compared with a mixed strategy. Further research is warranted to assess the risk-benefit ratio of the widespread adoption of total intravenous anaesthesia.

Time rescaling reproduces EEG behavior during transition from propofol anesthesia-induced unconsciousness to consciousness.

General anesthesia (GA) is a reversible manipulation of consciousness whose mechanism is mysterious at the level of neural networks leaving space for several competing hypotheses. We recorded electrocorticography (ECoG) signals in patients who underwent intracranial monitoring during awake surgery for the treatment of cerebral tumors in functional areas of the brain. Therefore, we recorded the transition from unconsciousness to consciousness directly on the brain surface. Using frequency resolved interferometry; we studied the intermediate ECoG frequencies (4-40 Hz). In the theoretical study, we used a computational Jansen and Rit neuron model to simulate recovery of consciousness (ROC). During ROC, we found that f increased by a factor equal to 1.62 ± 0.09, and δf varied by the same factor (1.61 ± 0.09) suggesting the existence of a scaling factor. We accelerated the time course of an unconscious EEG trace by an approximate factor 1.6 and we showed that the resulting EEG trace match the conscious state. Using the theoretical model, we successfully reproduced this behavior. We show that the recovery of consciousness corresponds to a transition in the frequency (f, δf) space, which is exactly reproduced by a simple time rescaling. These findings may perhaps be applied to other altered consciousness states.

Neuro-oncological patients admitted in intensive-care unit: predictive factors and functional outcome.

The prognosis of oncology patients admitted to the intensive care unit (ICU) is considered poor. Our objective was to analyze the characteristics and predictive factors of death in the ICU and functional outcome following ICU treatment for neuro-oncology patients. A retrospective study was conducted on all patients with primary brain tumor admitted to our institutional ICU for medical indications. Predictive impact on the risk of death in the ICU was analyzed as well as the functional status was evaluated prior and following ICU discharge. Seventy-one patients were admitted to the ICU. ICU admission indications were refractory seizures (41 %) and septic shock (17 %). On admission, 16 % had multi-organ failure. Ventilation was necessary for 41 % and catecholamines for 13 %. Twenty-two percent of patients died in the ICU. By multivariate analysis, predictive factors associated with an increased risk of ICU death were: non-neurological cause of admission [p = 0.045; odds ratio (OR) 5.405], multiple organ failure (p = 0.021; OR 8.027), respiratory failure (p = 0.006; OR 9.615), and hemodynamic failure (p = 0.008; OR 10.111). In contrast, tumor type (p = 0.678) and disease control status (p = 0.380) were not associated with an increased risk of ICU death. Among the 35 evaluable patients, 77 % presented with a stable or improved Karnofsky performance status following ICU hospitalization compared with the ongoing status before discharge. In patients with primary brain tumor admitted to the ICU, predictive factors of death appear to be similar to those described in non-oncology patients. ICU hospitalization is generally not associated with a subsequent decrease in the functional status.

[Meningitis to Candida albicans at the adult, use of the new diagnosis methods]. / Méningite à Candida albicans chez l'adulte, apport des nouveaux moyens diagnostiques.

Candida albicans or non-albicans are a frequent source of infection but seldom displayed in cerebrospinal fluid although responsible of an important number of nosocomial meningitis. Diagnosis is difficult which often delays treatment, which in turn hinders prognostic. This clinical case shows a patient afflicted with a deadly C. albicans meningitis and allows us to focus on new diagnostic tools and advice against this infection.

Controlled general anaesthesia for subthalamic nucleus stimulation in Parkinson's disease.

OBJECTIVE: To report the short-term (1 year) and long-term (5 years) outcome of patients with Parkinson's disease (PD) with subthalamic nucleus (STN) stimulation operated upon under controlled general anaesthesia (GA). METHODS: 213 consecutive patients with PD were included between January 2000 and March 2009 and operated upon under a particular type of GA with close control of the level of sedation allowing intraoperative recordings. 188 patients were assessed 1 year postoperatively. 65 patients also completed the long-term observation period and were evaluated 5 years postoperatively. RESULTS: The Unified PD Rating Scale III score in the 'Off drug--On stim' condition was improved at 1 year and 5 years by 61% and 37%, respectively, (p<0.001). Motor complications decreased at short-term and long-term by 68% and 65%, respectively, for dyskinesia and by 52% and 48%, respectively, for fluctuations, (p<0.001). Dopaminergic treatment could also be reduced at short-term and long-term by 46% and 49%, respectively (p<0.001). There was no significant modification of mood and cognition assessments (Mattis scale and Beck depression inventory) at 1 year and 5 years. Concerning the main adverse events related to the surgery, we report four haematomas (1.9%) with two deaths (0.9%), eight cases of transient confusion (3.7%) and no epileptic seizure. CONCLUSIONS: Our results confirm that STN stimulation performed under controlled GA is efficient and has similar short-term and long-term motor effects than intervention under local anaesthesia. Furthermore, this specific procedure is not associated with more adverse events. The success of such an intervention requires strict anaesthetic monitoring and accurate STN identification.

Effect of patient-controlled sedation with propofol on patient satisfaction: a randomized study.

BACKGROUND: In this trial we sought to determine whether propofol-based patient-controlled sedation (PCS) during diagnostic cerebral angiography would result in improved patient satisfaction compared to placebo-based PCS. METHODS: We randomly assigned 61 patients to receive propofol-based PCS (n=33, 15mg bolus in 9 s) or placebo-based PCS (n=28, bolus of 1.5mL of a 20% lipid emulsion in 9 s). We recorded the number of PCS bolus requirements, the need for rescue sedative drugs, and physiological variables. Prior to the procedure, the anxiety level of each patient was evaluated using the Anxiety State Traits Assessment (STAI) and the Amsterdam Preoperative Anxiety and Information Scale (APAIS). The quality of patient conditioning was quoted by both the anesthetist and neuroradiologist using Visual Analog Scale (VAS). The day following the procedure, patients were given the EVAN questionnaire, a validated tool for assessing patient satisfaction. RESULTS: Both groups were similar in term of demographics, American Society of Anesthesiologist (ASA) physical status scores, STAI and APAIS scores, and procedure lengths. There were no differences between groups in EVAN scores 76.9±16.1 vs. 75.7±12.8; P=0.78. The number of PCS bolus requirements was significantly higher in the placebo group 3.96±9.5 vs. 3.13±3.1 (P=0.02). No adverse event was recorded. CONCLUSION: This prospective, double-blind, randomized study showed that sedation using propofol PCS did not improve patients' satisfaction during diagnostic cerebral angiography. Therefore, an anesthetist should be rapidly available on request but not necessarily present during the whole procedure.

[Preoperative cardiac-risk assessment for non-cardiac surgery: The French RICARDO survey]. / Évaluation du Risque CARDiaque de l'Opéré (RICARDO) : enquête nationale auprès des anesthésistes-réanimateurs concernant la prise en charge périopératoire du patient à risque cardiaque.

OBJECTIVES: Professional practice evaluation of anaesthesiologist for high cardiac-risk patient cares in non-cardiac surgery, and assess disparities between results and recommendations. MATERIALS AND METHODS: Since June to September 2011, a self-questionnaire was sent to 5000 anesthesiologist. They were considered to be representative of national anesthesiology practitioner. Different items investigated concerned: demography, preoperative cardiac-risk assessment, modalities of specialized cardiologic advice, per- and postoperative care, and finally knowledge of current recommendations. RESULTS: We collected 1255 questionnaire, that is to say 25% of answers. Men were 73%, 38% were employed by public hospital; 70% worked in a shared operating theatre with a general activity. With regards to preoperative assessment, 85% of anaesthetists referred high cardiac-risk patient to a cardiologist. In only 16% of answer, Lee's score appeared in anaesthesia file to assess perioperative cardiac-risk. Only 61% considered the six necessary items to optimal estimate of cardiac-risk. On the other hand, 91% measured routinely the exercise capacities by interrogation. The most frequently doing exam (49% of anaesthetist) was an electrocardiogram in elderly patient. In 96% of case, beta-blockers were given in premedication if they were usually thought. Clopidogrel was stopped by 62% of anesthetist before surgery. In this case, 38% used another medication to take over from this one. Only 7% considered revascularization in coronary patient who were effectively treated. POISE study was know by 40% of practitioner, and 18% estimated that they have changed their practice. Preoperatively, 21% organized multidisciplinary approach for high-risk patient. During surgery, 63% monitored the ST-segment. In postoperative period for cardiac-risk patient, only 11% prescribed systematically an ECG, a troponin dosage, a postoperative monitoring of ST-segment, a cardiologic advice. In case of moderate troponin elevation, they were 70% to realize at least an ECG and/or an echocardiography. CONCLUSION: This study highlights some difference between current recommendation concerning assessment of cardiac-risk patient in non-cardiac surgery and daily practice of anesthetist, justifying regular update of this one.

[Cell therapy for stroke: from myth to reality]. / La thérapie cellulaire de l'accident vasculaire cérébral ischémique : du mythe à la réalité

INTRODUCTION: Stroke is one of the leading causes of death and disability worldwide. Intravenous recombinant tissue plasminogen activator is the only available therapy for acute ischemic stroke, but its use is limited by a narrow therapeutic window and cannot stimulate endogenous repair and regeneration of damaged brain tissue. Stem cell-based approaches hold much promise as potential novel treatments to restore neurological function after stroke. STATE OF THE ART: In this review, we summarize data from preclinical and clinical studies to investigate the potential application of stem cell therapies for treatment of stroke. Stem cells have been proposed as a potential source of new cells to replace those lost due to central nervous system injury, as well as a source of trophic molecules to minimize damage and promote recovery. Various stem cells from multiple sources can generate neural cells that survive and form synaptic connections after transplantation in the stroke-injured brain. Stem cells also exhibit neurorevitalizing properties that may ameliorate neurological deficits through stimulation of neurogenesis, angiogenesis and inhibition of inflammation. PERSPECTIVES/CONCLUSION: Performed in stroke, cell therapy would decrease brain damage and reduce functional deficits. After the damage has been done, it would still improve neurological functions by activating endogenous repair. Nevertheless, many questions raised by experimental studies particularly related to long-term safety and technical details of cell preparation and administration must be resolved before wider clinical use.

[Pulmonary embolism and intracranial hemorrhage: is there still an indication for a caval filter placement?]. / Embolie pulmonaire et hémorragie intracrânienne : existe-t-il encore des indications de filtre cave ?

The treatment of pulmonary embolism is mainly based on anticoagulants and intravenous thrombolysis in case of collapse. The cerebral hemorrhage is the main complication of thrombolysis and contraindicates anticoagulation. We report the case of a patient with a subdural and intraparenchymal hematoma complicating intravenous thrombolysis. The patient had persistent respiratory and hemodynamic instability related to the pursuit of embolic phenomena. The implementation of a cava filter was performed and the patient had a favorable outcome.

[Interest of EEG recording during direct electrical stimulation for brain mapping function in surgery]. / Intérêt du monitoring électrophysiologique au cours d'une chirurgie éveillée en neurochirurgie.

Brain tumor surgery is at risk when lesions are located in eloquent areas. The interindividual anatomo-functional variability of the central nervous system implies that brain surgery within eloquent regions may induce neurological sequelae. Brain mapping using intraoperative direct electrical stimulation in awake patients has been for long validated as the standard for functional brain mapping. Direct electrical stimulation inducing a local transient electrical and functional disorganization is considered positive if the task performed by the patient is disturbed. The brain area stimulated is then considered as essential for the function tested. However, the exactitude of the information provided by this technique is cautious because the actual impact of cortical direct electrical stimulation is not known. Indeed, the possibility of false negative (insufficient intensity of the stimulation due to the heterogeneity of excitability threshold of different cortical areas) or false positive (current spread, interregional signal propagation responsible for remote effects, which make difficult the interpretation of positive or negative behavioural effects) constitute a limitation of this technique. To improve the sensitivity and specificity of this technique, we used an electrocorticographic recording system allowing a real time visualization of the local. We provide here evidence that direct cortical stimulation combined with electrocorticographic recording could be useful to detect remote after discharge and to adjust stimulation parameters. In addition this technique offers new perspective to better assess connectivity of cerebral networks.

[Cardiac complications of acute brain injury]. / Complications cardiovasculaires de l'agression cérébrale.

The clinical importance of cardiovascular consequences resulting from cerebral injury has long been recognized. However, interactions between the brain and the cardiovascular system remain poorly defined and their importance for the management of patients suffering from acute brain injury is largely underestimated. This should have profound consequences on treatment strategies during anaesthesia and intensive cares of these patients, taking into account not only brain perfusion, but also cardiovascular optimisation. This report summarizes the main data available regarding the cardiovascular consequences of brain death, traumatic brain injury, stroke and epilepsy.

[EEG in intensive care unit: which indications, which material?]. / EEG en réanimation : quelles indications, quel matériel ?

There is a growing development of continuous EEG monitoring (cEEG) in the intensive care unit (ICU) management of neurological patients. Its main objective is the detection of epileptic seizures or status epilepticus because the sensitivity of standard short-duration EEG recording in the ICU is poor. The aim of monitoring is to allow rapid recognition and treatment of epileptic complications in order to decrease secondary insults to the brain and improve outcome. Several studies have demonstrated that a large proportion of patients has epileptic crisis after subarachnoid haemorrhage, stroke or brain trauma, without any clinical manifestation. The EEG feature has also demonstrated a prognosis value but its value for clinical management needs further studies. Another application of EEG in the ICU is monitoring depth of anaesthesia or barbiturate treatment. Due to artifacts contamination, this is possible only in deeply sedated of paralyzed patients. The impact or cEEG monitoring on clinical management and its indications have to be further defined.

Transient locked-in syndrome and basilar artery vasospasm.

BACKGROUND: Cerebral vasospasm is the main cause of neurological mortality and morbidity following subarachnoid hemorrhage. Basilar artery vasospasm (BAVS) is associated with a high morbidity and may have multiple clinical presentations. METHODS: We report the case of a 43 years-old man with BAVS presenting as a reversible locked-in syndrome (LIS) after stopping sedation. RESULTS: The symptoms were successfully managed by intra-arterial infusion of vasodilators and balloon angioplasty. Magnetic resonance imaging did not reveal any brainstem lesion 48 h after the complication, demonstrating a hemodynamic mechanism. CONCLUSION: LIS can reveal BAVS. Its diagnosis relies on clinical examination. In this case, rapid neuro-interventional treatment permitted reversal of symptoms. This could not have been possible under sedation.

Erythropoietin 2nd cerebral protection after acute injuries: a double-edged sword?

Over the past 15 years, a large body of evidence has revealed that the cytokine erythropoietin exhibits non-erythropoietic functions, especially tissue-protective effects. The discovery of EPO and its receptors in the central nervous system and the evidence that EPO is made locally in response to injury as a protective factor in the brain have raised the possibility that recombinant human EPO (rhEPO) could be administered as a cytoprotective agent after acute brain injuries. This review highlights the potential applications of rhEPO as a neuroprotectant in experimental and clinical settings such as ischemia, traumatic brain injury, and subarachnoid and intracerebral hemorrhage. In preclinical studies, EPO prevented apoptosis, inflammation, and oxidative stress induced by injury and exhibited strong neuroprotective and neurorestorative properties. EPO stimulates vascular repair by facilitating endothelial progenitor cell migration into the brain and neovascularisation, and it promotes neurogenesis. In humans, small clinical trials have shown promising results but large prospective randomized studies failed to demonstrate a benefit of EPO for brain protection and showed unwanted side effects, especially thrombotic complications. Recently, regions have been identified within the EPO molecule that mediate tissue protection, allowing the development of non-erythropoietic EPO variants for neuroprotection conceptually devoid of side effects. The efficacy and the safety profile of these new compounds are still to be demonstrated to obtain, in patients, the benefits observed in experimental studies.

[Early or delayed peripheral surgery in patients with severe head injury?]. / Chirurgie périphérique chez le traumatisé crânien grave: précoce ou retardée?

Head injuries are present in up to 65 % of multiple trauma patients with a frequent association with orthopaedic injuries. The concept of early surgical stabilization of long-bone fractures in patients with multiple injuries became firmly established in the 1980s. However, optimal timing of long bone fracture fixation in trauma patients with associated severe traumatic brain injury has been a lively topic. The available literature does not provide clear-cut guidance on the management of fractures in the presence of head injuries. The trend is toward a better outcome if the fractures are fixed early. In recent years, some studies reported a worse outcome, with secondary brain damage, resulting from hypotension, hypoxia and increased intraoperative fluid administration. This review summarises the current evidence available regarding the management of these patients in particular the recent concept of early temporary surgical stabilization in the era of "damage control orthopaedic surgery".

[Hypothermia for intracranial hypertension]. / Hypothermie et hypertension intracrânienne.

There is a large body of experimental evidence showing benefits of deliberate mild hypothermia (33-35 degrees C) on the injured brain as well as an improvement of neurological outcome after cardiac arrest in humans. However, the clinical evidence of any benefit of hypothermia following stroke, brain trauma and neonatal asphyxia is still lacking. Controversial results have been published in patients with brain trauma or neonatal asphyxia. Hypothermia can reduce the elevation of intracranial pressure, through mechanisms not completely understood. Hypothermia-induced hypocapnia should have a role on the reduction of intracranial pressure. The temperature target is unknown but no additional benefit was found below 34 degrees C. The duration of deliberate hypothermia for the treatment of elevated intracranial pressure might be at least 48 hours, and the subsequent rewarming period must be very slow to prevent adverse effects.

[Why should we inform the patients after difficult tracheal intubation?]. / Pourquoi une fiche d'information du patient après une intubation difficile?

Unanticipated difficult tracheal intubation may be challenging to anaesthesiologists. It is still associated with morbidity or mortality. Previous difficult intubation is vital information to organize appropriate airway management. Unfortunately, previous studies in the literature have shown that there is poor communication of this information. We propose in this article an airway alert form, following several criteria published in the literature. This is, in our opinion, an important step to improve the efficiency of guidelines on airway management and the overall quality of the anaesthesia process. Its efficacy to decrease morbidity related to difficult tracheal intubation remains to be demonstrated.