Assessing changes in regional cerebral hemodynamics in adults with a high-density full-head coverage time-resolved near-infrared spectroscopy device.

Significance: Cerebral oximeters have the potential to detect abnormal cerebral blood oxygenation to allow for early intervention. However, current commercial systems have two major limitations: (1) spatial coverage of only the frontal region, assuming that surgery-related hemodynamic effects are global and (2) susceptibility to extracerebral signal contamination inherent to continuous-wave near-infrared spectroscopy (NIRS). Aim: This work aimed to assess the feasibility of a high-density, time-resolved (tr) NIRS device (Kernel Flow) to monitor regional oxygenation changes across the cerebral cortex during surgery. Approach: The Flow system was assessed using two protocols. First, digital carotid compression was applied to healthy volunteers to cause a rapid oxygenation decrease across the ipsilateral hemisphere without affecting the contralateral side. Next, the system was used on patients undergoing shoulder surgery to provide continuous monitoring of cerebral oxygenation. In both protocols, the improved depth sensitivity of trNIRS was investigated by applying moment analysis. A dynamic wavelet filtering approach was also developed to remove observed temperature-induced signal drifts. Results: In the first protocol (28±5 years; five females, five males), hair significantly impacted regional sensitivity; however, the enhanced depth sensitivity of trNIRS was able to separate brain and scalp responses in the frontal region. Regional sensitivity was improved in the clinical study given the age-related reduction in hair density of the patients (65±15 years; 14 females, 13 males). In five patients who received phenylephrine to treat hypotension, different scalp and brain oxygenation responses were apparent, although no regional differences were observed. Conclusions: The Kernel Flow has promise as an intraoperative neuromonitoring device. Although regional sensitivity was affected by hair color and density, enhanced depth sensitivity of trNIRS was able to resolve differences in scalp and brain oxygenation responses in both protocols.

Characterizing the impact of thermoregulation in patients after cardiac arrest: a retrospective cohort study.

PURPOSE: Core body temperature has been extensively investigated as a thereuptic target in care after cardiac arrest. Nevertheless, the integrity of thermoregulation in patients after cardiac arrest has not been well studied. We sought to evaluate whether low spontaneous body temperature after cardiac arrest is associated with increased death and a worse neurologic outcome, and whether patients with low spontaneous body temperature exhibit features suggestive of impaired thermoregulation. METHODS: We conducted a single-centre retrospective cohort study. We included all adult patients who underwent temperature control with hypothermia after cardiac arrest between 1 January 2014 and 30 June 2020. The primary exposure was low spontaneous core body temperature (< 35 °C) at initiation of hypothermia therapy. The primary outcome was in-hospital death and the secondary outcome was poor neurologic outcomes at discharge. RESULTS: Five hundred and ninety-seven adult patients, comprising both in- and out-of-hospital cardiac arrests, were included. Patients with low spontaneous body temperature also had slightly lower average temperature, and more frequent transient but controlled breakthrough fever episodes in the first 24 hr. In the multivariable logistic regression analysis, low spontaneous body temperature was associated with higher odds of in-hospital death (odds ratio, 2.9; 95% confidence interval, 1.9 to 4.2; P < 0.001). CONCLUSION: In this single-centre retrospective cohort study, low spontaneous core body temperature was associated with poor outcomes in patients after cardiac arrest. Patients with low spontaneous body temperature also exhibited features suggestive of impaired thermoregulation. Further research is needed to determine whether body temperature upon presentation reflects the robustness of the patient's underlying physiology and severity of brain insult after a cardiac arrest.

RéSUMé: OBJECTIF: La température corporelle centrale a fait l'objet d'études approfondies en tant que cible thérapeutique dans les soins après un arrêt cardiaque. Néanmoins, l'intégrité de la thermorégulation après un arrêt cardiaque n'a pas été bien étudiée. Nous avons cherché à évaluer si une température corporelle spontanément basse après un arrêt cardiaque était associée à une augmentation de la mortalité et à une issue neurologique plus grave, et si les individus ayant une température corporelle spontanément basse présentaient des caractéristiques suggérant une altération de la thermorégulation. MéTHODE: Nous avons mené une étude de cohorte rétrospective monocentrique. Nous avons inclus tou·tes les patient·es adultes ayant bénéficié d'un contrôle de température lors d'une hypothermie après un arrêt cardiaque entre le 1er janvier 2014 et le 30 juin 2020. L'exposition principale était une température corporelle centrale spontanément basse (< 35 °C) au début du traitement de l'hypothermie. Le critère d'évaluation principal était le décès à l'hôpital, et le critère d'évaluation secondaire était de mauvaises issues neurologiques à la sortie de l'hôpital. RéSULTATS: Cinq cent quatre-vingt-dix-sept patient·es adultes, ayant subi des arrêts cardiaques à l'hôpital ou hors de l'hôpital, ont été inclus·es. Les patient·es ayant une température corporelle spontanément basse avaient également une température moyenne légèrement plus basse et des épisodes de fièvre paroxystique transitoires mais contrôlés plus fréquents au cours des premières 24 heures. Dans l'analyse de régression logistique multivariée, une température corporelle spontanément basse était associée à une probabilité plus élevée de décès à l'hôpital (rapport de cotes, 2,9; intervalle de confiance à 95 %, 1,9 à 4,2; P < 0,001). CONCLUSION: Dans cette étude de cohorte rétrospective monocentrique, une température corporelle centrale spontanément basse a été associée à de mauvais devenirs après un arrêt cardiaque. Les patient·es présentant une température corporelle spontanément basse présentaient également des caractéristiques suggérant une altération de la thermorégulation. D'autres recherches sont nécessaires pour déterminer si la température corporelle lors de la présentation reflète la robustesse de la physiologie sous-jacente des patient·es et la gravité de la lésion cérébrale après un arrêt cardiaque.

Real-time 3D Transesophageal Echocardiography for the Placement of Ventriculoatrial Shunt: A Case Series and Technical Note.

BACKGROUND: Ventriculoatrial (VA) shunts are used to manage hydrocephalus and idiopathic intracranial hypertension when peritoneal drainage of cerebrospinal fluid is not feasible. The technique of distal catheter placement during VA shunt insertion is controversial, especially between fluoroscopy-guided and transesophageal echocardiography (TEE)-guided techniques. METHODS: We retrospectively reviewed our utilization of 2-dimensional (2D) ultrasound-guided internal jugular vein catheterization combined with 3-dimensional (3D) TEE-guided distal VA shunt placement and compared it to the conventional fluoroscopy-guided technique. RESULTS: Ten patients underwent 18 VA shunt insertion procedures between November 2012 and October 2022. The patients had a mean (SD) age of 50 (19) years, body mass index of 35 (14) m/kg², and minimal comorbidities. All had previously undergone failed ventriculoperitoneal shunt procedures. The use of 2D ultrasound to guide internal jugular vein catheterization and 3D TEE to guide distal catheter placement resulted in 22-minute shorter surgical times compared with the fluoroscopy-guided technique (91 minutes vs. 113 minutes, respectively). No complications were noted with either technique. CONCLUSIONS: The combined use of 2D ultrasound and 3D TEE allowed for faster procedure times and more precise distal catheter confirmation, contributing to a more streamlined surgical procedure. This small case series underscores the feasibility, efficiency, and safety of anesthesiologist-delivered combined 2D ultrasound and 3D TEE during VA shunt insertion. The use of 3D TEE allows repeated confirmation of distal catheter position and has potential to improve patient safety during rare but complex VA shunt insertion procedures.

Preoperative assessment of postoperative delirium: a cross-sectional study of patients and anesthesiologists in Canada.

PURPOSE: We sought to evaluate 1) patient- and anesthesiologist-reported rates of postoperative delirium (POD) risk discussion during preoperative meetings, 2) patients' and anesthesiologists' ratings of the importance of POD, and 3) predictors of patient-reported discussion of POD risk during preoperative meetings. METHODS: In this multicentre two-part cross-sectional survey study, patients ≥ 65 yr scheduled to undergo elective noncardiac surgery completed a five-minute survey after preoperative anesthesia consultation. Patients were asked about their perception of POD importance, and whether they discussed or were assessed for POD risk. Anesthesiologists were surveyed using self-administered surveys circulated via institutional email lists. Anesthesiologists were asked about the frequency of POD risk assessment and discussion in older adults, tools used, and perception of POD-screening barriers. RESULTS: Four hundred and twelve (of 510 approached) patients (50% male; mean age, 73 yr) and 267 anesthesiologists (of 1,205 invited via e-mail) participated in this study conducted in five Canadian hospitals. Postoperative delirium screening and discussion was reported by 88/412 (22%) patients and 229/267 (86%) anesthesiologists. Postoperative delirium was rated as "somewhat-extremely" important by 64% of patients. A previous history of delirium, higher education, the number of daily medications, and longer surgical duration were associated with POD discussion. On average, anesthesiologists rated the importance of POD at 8/10, and 42% ranked "patient risk factors" as the top reason prompting discussion. CONCLUSION: The combined evaluation of patients' and anesthesiologists' perspectives provides valuable information on preoperative POD screening and risk assessment, and highlights areas for improvement in the current practice. Most factors we identified to be associated with higher odds of POD discussion are recognized risk factors of POD.

RéSUMé: OBJECTIF: Nous avons cherché à évaluer 1) les taux de discussion concernant le risque de delirium postopératoire (DPO) déclarés par les patient·es et les anesthésiologistes lors des rencontres préopératoires, 2) les évaluations des patient·es et des anesthésiologistes de l'importance de DPO, et 3) les prédicteurs d'une discussion telle que rapportée par les patient·es sur le risque de DPO pendant les rencontres préopératoires. MéTHODE: Dans ce sondage transversal multicentrique en deux parties, les patient·es ≥ 65 ans devant subir une chirurgie non cardiaque non urgente ont rempli un sondage de cinq minutes après la consultation d'anesthésie préopératoire. Les patient·es ont été interrogé·es sur leur perception de l'importance du DPO et si leur risque de DPO avait été discuté ou évalué. Des sondages auto-administrés ont été distribués aux anesthésiologistes via les listes de courriels institutionnelles. Ce sondage interrogeait les anesthésiologistes quant à la fréquence de l'évaluation et de la discussion des risques de DPO chez les personnes âgées, aux outils utilisés et à la perception des obstacles au dépistage de DPO. RéSULTATS: Quatre cent douze (des 510 personnes approchées) patient·es (50 % d'hommes; âge moyen, 73 ans) et 267 anesthésiologistes (sur 1205 invité·es par courriel) ont participé à cette étude menée dans cinq hôpitaux canadiens. Le dépistage et la discussion sur le delirium postopératoire ont été signalés par 88/412 (22 %) des patient·es et 229/267 (86 %) des anesthésiologistes. Le delirium postopératoire a été jugé « assez ­ extrêmement ¼ important par 64 % des patient·es. Des antécédents de delirium, des études supérieures, le nombre de médicaments quotidiens et une durée chirurgicale plus longue ont été associés à la discussion sur le DPO. En moyenne, les anesthésiologistes ont évalué l'importance du DPO à 8/10, et 42 % ont classé les « facteurs de risque liés au/à la patient·e ¼ comme la principale raison suscitant la discussion. CONCLUSION: L'évaluation combinée des points de vue des patient·es et des anesthésiologistes fournit des informations précieuses sur le dépistage préopératoire des DPO et l'évaluation des risques, et met en évidence les domaines à améliorer dans la pratique actuelle. La plupart des facteurs que nous avons identifiés comme étant associés à des probabilités plus élevées de discussion sur le DPO sont des facteurs de risque reconnus de DPO.

Point-of-care lung and cardiac ultrasound (LUCAS) study in hip fracture patients: a prospective cohort study.

PURPOSE: A clinical conflict often presented with hip fracture patients is whether to proceed with timely surgery or delay surgery until a formal echocardiogram is conducted. This study aimed to assess the impact of incorporating point-of-care lung and cardiac ultrasound (LUCAS) scans as part of the preoperative assessment for hip fracture patients. METHODS: We recruited 225 consecutive adult patients booked for urgent hip arthroplasty surgery. A LUCAS scan was performed for each patient. The anesthesiologists were asked to provide their anesthetic plans before and after acknowledging the results of the LUCAS scans. The primary endpoint was a composite outcome of changes to the anesthetic plan. The secondary outcomes included anesthesiologists' opinions of the LUCAS scans. RESULTS: One-hundred-ninety-eight patients were included. The majority of LUCAS findings were not severe. A common abnormal finding was hypovolemia (31%). One-hundred-and-six anesthetic management decisions were changed, with 59 of these changes being an escalation of the anesthetic plan, and 47 of these changes being a de-escalation. Eighty-three percent of anesthesiologists agreed that LUCAS affirmed their anesthetic plans and should be an integral part of the perioperative assessment. CONCLUSION: This study found that LUCAS scans did not significantly alter the anesthetic plan for hip fracture patients. Nevertheless, LUCAS scans can rule out severe cardiopulmonary conditions and allow for both escalation and de-escalation of care. In the setting of early hip surgery, LUCAS presents a viable option in selected patients to address the unmet need to allow for both timely surgery and comprehensive patient evaluation. STUDY REGISTRATION: ClinicalTrials.gov (NCT03275129); registered 8 July 2018.

RéSUMé: OBJECTIF: Une interrogation clinique qui existe souvent avec les patient·es se présentant avec une fracture de hanche est de savoir s'il faut procéder à une intervention chirurgicale rapidement ou retarder la chirurgie jusqu'à ce qu'un échocardiogramme formel soit réalisé. Cette étude visait à évaluer l'impact de l'intégration de l'échographie ciblée pulmonaire et cardiaque (LUCAS, Lung and Cardiac ultrasound) dans le cadre de l'évaluation préopératoire des personnes ayant subi une fracture de la hanche. MéTHODE: Nous avons recruté 225 patient·es adultes consécutif·ves devant bénéficier d'une arthroplastie urgente de la hanche. Une échographie de type LUCAS a été réalisée pour chaque patient·e. On a demandé aux anesthésiologistes de fournir leurs plans anesthésiques avant et après avoir pris connaissance des résultats des échographies de type LUCAS. Le critère d'évaluation principal était un résultat composite des modifications apportées au plan anesthésique. Les critères d'évaluation secondaires comprenaient les opinions des anesthésiologistes sur les échographies de type LUCAS. RéSULTATS: Cent quatre-vingt-dix-huit patient·es ont été inclus·es. La majorité des résultats de l'échographie de type LUCAS n'étaient pas graves. Un résultat anormal courant était l'hypovolémie (31 %). Cent six décisions de prise en charge anesthésique ont été modifiées, 59 de ces changements étant une escalade du plan anesthésique et 47 de ces changements étant une réduction. Quatre-vingt-trois pour cent des anesthésiologistes ont convenu que l'échographie de type LUCAS confirmait leurs plans anesthésiques et devrait faire partie intégrante de l'évaluation périopératoire. CONCLUSION: Cette étude a révélé que les échographies de type LUCAS ne modifiaient pas de manière significative le plan anesthésique pour les patient·es se présentant avec une fracture de hanche. Néanmoins, les échographies de type LUCAS peuvent exclure des affections cardiopulmonaires graves et permettre à la fois d'augmenter ou de réduire les soins périopératoires. Dans le cadre d'une chirurgie précoce de la hanche, l'échographie de type LUCAS présente une option viable chez une patientèle sélectionnée pour répondre à un besoin non satisfait afin de permettre à la fois une chirurgie rapide et une évaluation complète des patient·es. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT03275129); enregistrée le 8 juillet 2018.

Assessing the Sensitivity of Multi-Distance Hyperspectral NIRS to Changes in the Oxidation State of Cytochrome C Oxidase in the Brain.

Near-infrared spectroscopy (NIRS) measurements of tissue oxygen saturation (StO2) are frequently used during vascular and cardiac surgeries as a non-invasive means of assessing brain health; however, signal contamination from extracerebral tissues remains a concern. As an alternative, hyperspectral (hs)NIRS can be used to measure changes in the oxidation state of cytochrome c oxidase (ΔoxCCO), which provides greater sensitivity to the brain given its higher mitochondrial concentration versus the scalp. The purpose of this study was to evaluate the depth sensitivity of the oxCCO signal to changes occurring in the brain and extracerebral tissue components. The oxCCO assessment was conducted using multi-distance hsNIRS (source-detector separations = 1 and 3 cm), and metabolic changes were compared to changes in StO2. Ten participants were monitored using an in-house system combining hsNIRS and diffuse correlation spectroscopy (DCS). Data were acquired during carotid compression (CC) to reduce blood flow and hypercapnia to increase flow. Reducing blood flow by CC resulted in a significant decrease in oxCCO measured at rSD = 3 cm but not at 1 cm. In contrast, significant changes in StO2 were found at both distances. Hypercapnia caused significant increases in StO2 and oxCCO at rSD = 3 cm, but not at 1 cm. Extracerebral contamination resulted in elevated StO2 but not oxCCO after hypercapnia, which was significantly reduced by applying regression analysis. This study demonstrated that oxCCO was less sensitive to extracerebral signals than StO2.

Early Goal-directed Therapy During Endovascular Coiling Procedures Following Aneurysmal Subarachnoid Hemorrhage: A Pilot Prospective Randomized Controlled Study.

BACKGROUND: Maintenance of euvolemia and cerebral perfusion are recommended for the prevention of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). We conducted a pilot randomized controlled study to assess the feasibility and efficacy of goal-directed therapy (GDT) to correct fluid and hemodynamic derangements during endovascular coiling in patients with aSAH. METHODS: This study was conducted between November 2015 and February 2019 at a single tertiary center in Canada. Adult patients with aSAH within 5 days of aneurysm rupture were randomly assigned to receive either GDT or standard therapy during endovascular coiling. The incidence of dehydration at presentation and the efficacy of GDT were evaluated. RESULTS: Forty patients were allocated to receive GDT (n=21) or standard therapy (n=19). Sixty percent of all patients were found to have dehydration before the coiling procedure commenced. Compared with standard therapy, GDT reduced the duration of intraoperative hypovolemia (mean difference 37.6 [95% confidence interval, 6.2-37.4] min, P=0.006) and low cardiac index (mean difference 30.7 [95% confidence interval, 9.5-56.9] min, P=0.035). There were no differences between the 2 treatment groups with respect to the incidence of vasospasm, stroke, death, and other complications up to postoperative day 90. CONCLUSIONS: A high proportion of aSAH patients presented at the coiling procedure with dehydration and a low cardiac output state; these derangements were more likely to be corrected if the GDT algorithm was used. Compared with standard therapy, use of the GDT algorithm resulted in earlier recognition and more consistent treatment of dehydration and hemodynamic derangement during endovascular coiling.

Efficacy of perioperative pharmacological and regional pain interventions in adult spine surgery: a network meta-analysis and systematic review of randomised controlled trials.

BACKGROUND: Development of a widely accepted standardised analgesic pathway for adult spine surgery has been hampered by the lack of quantitative analysis. We conducted a systematic review and network meta-analysis (NMA) to compare, rank, and grade all pharmacological and regional interventions used in adult spine surgery. METHODS: A systematic search was performed in January 2021. We performed double study screening, selection, and data extraction. The co-primary outcomes were cumulative morphine consumption (mg) and visual analogue pain score (range 0-10) at postoperative 24 h. An NMA was performed using the Bayesian approach (random effects model). We also ranked and graded all analgesic interventions using the Grading of Recommendations Assessment, Development and Evaluation approach for NMA. RESULTS: We screened 5908 studies and included 86 randomised controlled studies, which comprised 6284 participants. Of 20 pharmacological and 10 regional interventions, the most effective intervention was triple-drug therapy, consisting of paracetamol, nonsteroidal anti-inflammatory drugs, and adjunct. The pooled mean reduction in morphine consumption and pain score at postoperative 24 h were -26 (95% credible interval [CrI]: -39 to -12) mg and -2.3 (95% CrI: -3.1 to -1.4), respectively. Double-drug therapy was less effective, but showed moderate morphine reduction in a range of -15 to -17 mg and pain score reduction in a range of -1 to -1.6. Single-agent interventions were largely ineffective. CONCLUSIONS: Triple-drug therapy is the most effective pain intervention in adult spine surgery with moderate-to-high certainty of evidence. We have also identified a graded analgesic effect, in which analgesic efficacy increased with the number of multimodal drugs used. SYSTEMATIC REVIEW REGISTRATION: PROSPERO (CRD42020171326).

Automated Nerve Monitoring in Shoulder Arthroplasty: A Prospective Randomized Controlled Study.

BACKGROUND: Evoked potential monitoring is believed to prevent neurologic injury in various surgical settings; however, its clinical effect has not been scrutinized. It was hypothesized that an automated nerve monitor can minimize intraoperative nerve injury and thereby improve clinical outcomes in patients undergoing shoulder arthroplasty. METHODS: A prospective, blinded, parallel group, superiority design, single-center, randomized controlled study was conducted. Study participants were equally randomized into either the automated nerve-monitored or the blinded monitored groups. The primary outcome was intraoperative nerve injury burden as assessed by the cumulative duration of nerve alerts. Secondary outcomes were neurologic deficits and functional scores of the operative arm, and the quality of life index (Euro Quality of life-5 domain-5 level score) at postoperative weeks 2, 6, and 12. RESULTS: From September 2018 to July 2019, 213 patients were screened, of whom 200 were randomized. There was no statistically significant difference in the duration of nerve alerts between the automated nerve-monitored and control groups (median [25th, 75th interquartile range]: 1 [0, 18] and 5 [0, 26.5]; Hodges-Lehman difference [95% CI]: 0 [0 to 1] min; P = 0.526). There were no statistically significant differences in secondary outcomes between groups. However, in the ancillary analysis, there were reductions in neurologic deficits and improvements in quality of life index occurring in both groups over the course of the study period. CONCLUSIONS: Protection from nerve injury is a shared responsibility between surgeons and anesthesiologists. Although a progressive improvement of clinical outcomes were observed over the course of the study in both groups as a consequence of the real-time feedback provided by the automated nerve monitor, this trial did not demonstrate that automated nerve monitoring by itself changes important clinical outcomes compared with no monitoring.

A novel approach of using brachial plexus blockade as an experimental model for diagnosis of intraoperative nerve dysfunction with somatosensory evoked potentials: a blinded proof-of-concept study.

PURPOSE: Intraoperative nerve dysfunction has been difficult to investigate because of its rarity and unpredictable occurrence. The diagnostic test attributes of nerve function monitors have not been clearly defined. This proof-of-concept study aimed to assess the feasibility of using brachial plexus blockade (BPB) in awake patients as an experimental model for nerve dysfunction to characterize the diagnostic test attributes of somatosensory evoked potentials (SSEPs). METHODS: We obtained baseline SSEPs and neurologic function in patients and subsequently placed BPBs (experimental model) to generate progressive states of nerve dysfunction. We monitored SSEP changes (index test) and neurologic symptoms (reference standard) simultaneously during the onset of BPB to determine the temporal relationships and diagnostic test attributes of SSEPs. RESULTS: Brachial plexus blockade produced differential motor and sensory dysfunction that allowed simultaneous clinical and neurophysiologic assessment. One hundred and fifty-seven pairs of multiple data points from 14 patients were included for final analysis. The onset of abnormal SSEP signals almost always preceded the onset of neurologic symptoms. The sensitivities and specificities of SSEP to detect the impairment of power (motor rating score ≤ 4/5), cold sensation, and two-point discrimination were 100% and 67%, 99% and 55%, and 100% and 46%, respectively. CONCLUSION: This study found that BPB can produce sufficient differential nerve dysfunction to allow adequate evaluation of the diagnostic test attributes of SSEPs as a nerve monitor. The results of this study may stimulate further work on refining intraoperative nerve dysfunction models and diagnostic nerve function monitors. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT03409536); registered 24 January 2018.

RéSUMé: OBJECTIF: La dysfonction nerveuse peropératoire est difficile à étudier en raison de sa rareté et de son imprévisibilité. Les attributs d'un test diagnostique des moniteurs de la fonction nerveuse n'ont pas été clairement définis. Cette étude de démonstration de faisabilité visait à évaluer la faisabilité de l'utilisation d'un bloc du plexus brachial (BPB) chez des patients éveillés comme modèle expérimental de la dysfonction nerveuse afin de caractériser les attributs de test diagnostique des potentiels évoqués somesthésiques (PES). MéTHODE: Nous avons enregistré les PES et la fonction neurologique de base des patients, puis administré des BPB (modèle expérimental) pour générer des états progressifs de dysfonction nerveuse. Nous avons surveillé simultanément les changements des PES (test pour déterminer l'indicateur) et les symptômes neurologiques (norme de référence) pendant l'évolution du BPB afin de déterminer les relations temporelles et les attributs de test diagnostique des PES. RéSULTATS: Le bloc du plexus brachial a produit une dysfonction motrice et sensorielle différentielle qui nous a permis de procéder à une évaluation clinique et neurophysiologique simultanée. Cent cinquante-sept paires de points de données multiples issues de 14 patients ont été incluses pour l'analyse finale. L'apparition de signaux de PES anormaux a presque toujours précédé l'apparition de symptômes neurologiques. Les sensibilités et les spécificités des PES pour détecter la perte de force (score moteur ≤ 4/5), la sensation de froid et la discrimination à deux points étaient de 100 % et 67 %, 99 % et 55 %, et 100 % et 46 %, respectivement. CONCLUSION: Cette étude a constaté que le bloc du plexus brachial peut produire une dysfonction nerveuse différentielle suffisante pour permettre l'évaluation adéquate des attributs de test diagnostique des PES en tant que moniteur nerveux. Les résultats de cette étude pourraient motiver d'autres travaux sur l'amélioration des modèles de dysfonction nerveuse peropératoire et des moniteurs diagnostiques de la fonction nerveuse. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT03409536); enregistrée le 24 janvier 2018.

Optical monitoring of cerebral perfusion and metabolism in adults during cardiac surgery with cardiopulmonary bypass.

During cardiac surgery with cardiopulmonary bypass (CPB), adequate maintenance of cerebral blood flow (CBF) is vital in preventing postoperative neurological injury - i.e. stroke, delirium, cognitive impairment. Reductions in CBF large enough to impact cerebral energy metabolism can lead to tissue damage and subsequent brain injury. Current methods for neuromonitoring during surgery are limited. This study presents the clinical translation of a hybrid optical neuromonitor for continuous intraoperative monitoring of cerebral perfusion and metabolism in ten patients undergoing non-emergent cardiac surgery with non-pulsatile CPB. The optical system combines broadband near-infrared spectroscopy (B-NIRS) to measure changes in the oxidation state of cytochrome c oxidase (oxCCO) - a direct marker of cellular energy metabolism - and diffuse correlation spectroscopy (DCS) to provide an index of cerebral blood flow (CBFi). As the heart was arrested and the CPB-pump started, increases in CBFi (88.5 ± 125.7%) and significant decreases in oxCCO (-0.5 ± 0.2 µM) were observed; no changes were noted during transitions off CPB. Fifteen hypoperfusion events, defined as large and sustained reductions in CPB-pump flow rate, were identified across all patients and resulted in significant decreases in perfusion and metabolism when mean arterial pressure dropped to 30 mmHg or below. The maximum reduction in cerebral blood flow preceded the corresponding metabolic reduction by 18.2 ± 15.0 s. Optical neuromonitoring provides a safe and non-invasive approach for assessing intraoperative perfusion and metabolism and has potential in guiding patient management to prevent adverse clinical outcomes.

Postoperative hemodynamic management in patients undergoing resection of cerebral arteriovenous malformations: A retrospective study.

Strict control of blood pressure (BP) has been recommended in patients after surgical resection of cerebral arteriovenous malformations (AVM) to prevent postoperative hyperemic complication. The aim of this study was to review the postoperative hemodynamic management in patients after surgical resection of cerebral AVM and the incidence of postoperative intracranial hemorrhage and/or cerebral edema. After the ethics approval, we retrospectively reviewed the medical records of 207 adult patients who underwent elective surgical resection of cerebral AVM from Jan 2005 to Oct 2016 in a single university hospital. We determined the incidence of postoperative symptomatic intracranial hemorrhage and/or cerebral edema, and reviewed the quality of postoperative BP control during the first 72 h postoperatively. Two hundred and seven patients who underwent cerebral AVM resection were included. The median (IQR) of postoperative maximal systolic BP target was 110 (100-120) mmHg but the range was 90-150 mmHg. Failed hemodynamic control was consistently found in half of the patients during the first 72 h postoperatively. The incidence of postoperative intracranial hemorrhage and/or cerebral edema was 4.4% (9/207 patients). All 9 of these patients experienced a hypertensive event prior to their postoperative hyperemic complication. Two patients required induced hypertension to treat postoperative symptomatic cerebral edema. We concluded that postoperative intracranial hemorrhage and/or cerebral edema is not an uncommon complication after surgical resection of cerebral AVM. Further studies are required to develop a more effective strategy to implement strict BP control in the postoperative period.

Knowledge and perceptions about perioperative stroke: a cross-sectional survey of patients scheduled for non-neurologic and non-cardiac surgery.

PURPOSE: Perioperative stroke is associated with significant morbidity and mortality yet patients may not be aware of their risk or receive appropriate counselling. Our objectives were to 1) compare patient's perceived vs calculated risk of stroke; 2) determine level of worry; and 3) assess prior discussion about perioperative stroke risk amongst elective patients undergoing non-cardiac, non-neurologic surgery. METHODS: Over a consecutive four-week period, surveys were distributed at two pre-anesthetic clinics to adult patients scheduled for non-cardiac, non-neurologic surgery. The survey included questions about demographics, perioperative stroke risk factors, patient perception of their quantitative and qualitative stroke risk, level of worry about stroke, and risk discussions. We identified independent predictors of risk underestimation amongst medium- and high-risk patients. RESULTS: Six hundred patients completed the survey (response rate 78%). Of these, 479, 104, and 15 patients were classified as low-, medium-, and high-risk, respectively (with two patients missing this data point). Most medium- (86%) and high-risk (80%) patients did not identify their elevated risk. Amongst medium- and high-risk patients, independent predictors of risk underestimation were lower education and absence of kidney disease. Medium- and high-risk patients were more worried than low-risk patients about perioperative stroke (median [interquartile range] visual analogue scale score 2 [0.5-4] vs 1 [0-2], P = 0.001). Fewer than half of patients had discussed perioperative stroke previously (40%, 23%, and 12% of high-, medium-, and low-risk patients, respectively). CONCLUSIONS: Patients at higher risk of stroke frequently underestimate their risk of perioperative stroke. The majority of patients had not discussed perioperative stroke prior to anesthetic consultation.

Anesthetic management of complex spine surgery in adult patients: a review based on outcome evidence.

PURPOSE OF REVIEW: The aim of this article is to review the evidence regarding the anesthetic management of blood loss, pain control, and position-related complications of adult patients undergoing complex spine procedures. RECENT FINDINGS: The most recent evidence of the anesthetic management of complex spine surgery was identified with a systematic search and graded. In our review, prophylactic tranexamic acid and optimal prone positioning were shown to be effective blood conservation strategies with minimal risks to the patients. Cell saver was cost-effective in complex surgeries with expected blood loss of greater than 500 ml. As for pain control, most interventions only produced mild analgesic effects, suggesting a multimodal approach is necessary to achieve optimal pain control after spine surgery. Regional techniques and NSAIDs were effective but because of their risks, their usage should be discussed with the surgical team. Further studies are required to assess the effectiveness, cost-effectiveness, and risks associated with combined uses of different analgesic interventions. On the basis of the available evidence, we recommend a combined use of gabapentinoids, ketamine, and opioids to achieve optimal analgesia. Lastly, literature for position-related injuries is heavily relied on case reports and the Anesthesia Closed Claim Study because of their rarity. Therefore, we advocate for a structured team-based approach with checklists to minimize position-related complications. SUMMARY: As the number and complexity of spine procedures are being performed worldwide is increasing, we suggested to bundle the aforementioned effective interventions as part of an ERAS spine protocol to improve the patient outcome of spine surgery.

Intraoperative evoked potential monitoring for detecting cerebral injury during adult aneurysm clipping surgery: a systematic review and meta-analysis of diagnostic test accuracy.

OBJECTIVES: We aim to evaluate the diagnostic test accuracy (DTA) of intraoperative evoked potential (EP) monitoring to detect cerebral injury during clipping of cerebral aneurysms. DESIGN: Systematic review. DATA SOURCES: Major electronic databases including MEDLINE, EMBASE, LILACS. ELIGIBILITY CRITERIA: We included studies that reported the DTA of intraoperative EP monitoring during intracranial aneurysm clipping procedures in adult patients. DATA EXTRACTION AND SYNTHESIS: After quality assessment, we performed a meta-analysis using the bivariate random effects model, and calculated the possible range of DTA point estimates using a new best-case/worst-case scenario approach to quantify the impact of rescue intervention on DTA. RESULTS: A total of 35 studies involving 4011 patients were included. The quality of the primary studies was modest and the heterogeneity across studies was high. The pooled sensitivity and specificity for predicting postoperative neurological deficits for the somatosensory evoked potential (SSEP) monitoring was 59% (95% CI: 39% to 76%; I2: 76%) and 86% (95% CI: 77% to 92%; I2: 94%), for motor evoked potential (MEP) monitoring was 81% (95% CI: 58% to 93%; I2: 54%) and 90% (95% CI: 86% to 93%; I2: 81%), and for combined SSEP and MEP monitoring was 92% (95% CI: 62% to 100%) and 88% (95% CI: 83% to 93%). The best-case/worst-case range for the pooled point estimates for sensitivity and specificity for SSEP was 50%-63% and 81%-100%, and for MEP was 59%-74% and 93%-100%, and for combined SSEP and MEP was 89%-94% and 83%-100%. CONCLUSIONS: Due to the modest quality and high heterogeneity of the existing primary studies, it is not possible to confidently support or refute the diagnostic value of EP monitoring in cerebral aneurysm clipping surgery. However, combined SSEP and MEP appears to provide the best DTA for predicting postoperative stroke. Contrary to popular assertion, the modest sensitivity of SSEP monitoring is not explained by the use of rescue intervention. PROSPERO REGISTRATION NUMBER: CRD42015016884.