Epidural Catheterization in Cardiac Surgery: A Systematic Review and Risk Assessment of Epidural Hematoma.

ABSTRACT: The potential benefits of epidural anesthesia on mortality, atrial fibrillation, and pulmonary complications must be weighed against the risk of epidural hematoma associated with intraoperative heparinization. This study aims to provide an updated assessment of the clinical risks of epidural anesthesia in cardiac surgery, focusing on the occurrence of epidural hematomas and subsequent paralysis. A systematic search of Embase, Medline, Ovid Central, Web of Science, and PubMed was conducted to identify relevant publications between 1966 and 2022. Two independent reviewers assessed the eligibility of the retrieved manuscripts. Studies reporting adult patients undergoing cardiac surgery with epidural catheterization were included. The incidence of hematomas was calculated by dividing the number of hematomas by the total number of patients in the included studies. Risk calculations utilized various denominators based on the rigor of trial designs, and the risks of hematoma and paralysis were compared to other commonly encountered risks. The analysis included a total of 33,089 patients who underwent cardiac surgery with epidural catheterization. No epidural hematomas were reported across all published RCTs, prospective, and retrospective trials. Four case reports associated epidural hematoma with epidural catheterization and perioperative heparinization. The risks of epidural hematoma and subsequent paralysis were estimated at 1:7643 (95% CI 1:3860 to 380,916) and 1:10,190 (95% CI 1:4781 to 0:1), respectively. The risk of hematoma is similar to the non-obstetric population (1:5405; 95% CI 1:4784 to 6134). The risk of hematoma in cardiac surgery patients receiving epidural anesthesia is therefore similar to that observed in some other surgical non-obstetric populations commonly exposed to epidural catheterization.

Novel Preoperative Risk Stratification Using Digital Phenotyping Applying a Scalable Machine-Learning Approach.

BACKGROUND: Classification of perioperative risk is important for patient care, resource allocation, and guiding shared decision-making. Using discriminative features from the electronic health record (EHR), machine-learning algorithms can create digital phenotypes among heterogenous populations, representing distinct patient subpopulations grouped by shared characteristics, from which we can personalize care, anticipate clinical care trajectories, and explore therapies. We hypothesized that digital phenotypes in preoperative settings are associated with postoperative adverse events including in-hospital and 30-day mortality, 30-day surgical redo, intensive care unit (ICU) admission, and hospital length of stay (LOS). METHODS: We identified all laminectomies, colectomies, and thoracic surgeries performed over a 9-year period from a large hospital system. Seventy-seven readily extractable preoperative features were first selected from clinical consensus, including demographics, medical history, and lab results. Three surgery-specific datasets were built and split into derivation and validation cohorts using chronological occurrence. Consensus k -means clustering was performed independently on each derivation cohort, from which phenotypes' characteristics were explored. Cluster assignments were used to train a random forest model to assign patient phenotypes in validation cohorts. We reconducted descriptive analyses on validation cohorts to confirm the similarity of patient characteristics with derivation cohorts, and quantified the association of each phenotype with postoperative adverse events by using the area under receiver operating characteristic curve (AUROC). We compared our approach to American Society of Anesthesiologists (ASA) alone and investigated a combination of our phenotypes with the ASA score. RESULTS: A total of 7251 patients met inclusion criteria, of which 2770 were held out in a validation dataset based on chronological occurrence. Using segmentation metrics and clinical consensus, 3 distinct phenotypes were created for each surgery. The main features used for segmentation included urgency of the procedure, preoperative LOS, age, and comorbidities. The most relevant characteristics varied for each of the 3 surgeries. Low-risk phenotype alpha was the most common (2039 of 2770, 74%), while high-risk phenotype gamma was the rarest (302 of 2770, 11%). Adverse outcomes progressively increased from phenotypes alpha to gamma, including 30-day mortality (0.3%, 2.1%, and 6.0%, respectively), in-hospital mortality (0.2%, 2.3%, and 7.3%), and prolonged hospital LOS (3.4%, 22.1%, and 25.8%). When combined with the ASA score, digital phenotypes achieved higher AUROC than the ASA score alone (hospital mortality: 0.91 vs 0.84; prolonged hospitalization: 0.80 vs 0.71). CONCLUSIONS: For 3 frequently performed surgeries, we identified 3 digital phenotypes. The typical profiles of each phenotype were described and could be used to anticipate adverse postoperative events.

A randomized controlled trial comparing three supraglottic airway devices used as a conduit to facilitate tracheal intubation with flexible bronchoscopy.

PURPOSE: Once difficult ventilation and intubation are declared, guidelines suggest the use of a supraglottic airway (SGA) as a rescue device to ventilate and, if oxygenation is restored, subsequently as an intubation conduit. Nevertheless, few trials have formally studied recent SGA devices in patients. Our objective was to compare the efficacy of three second-generation SGA devices as conduits for bronchoscopy-guided endotracheal intubation. METHODS: In this prospective, single-blinded three-arm randomized controlled trial, patients with an American Society of Anesthesiologists Physical Status of I-III undergoing general anesthesia were randomized to bronchoscopy-guided endotracheal intubation using AuraGain™, Air-Q® Blocker, or i-gel® devices. We excluded patients with contraindications to an SGA or drugs and who were pregnant or had a neck, spine, or respiratory anomaly. The primary outcome was intubation time, measured from SGA circuit disconnection to CO2 measurement. Secondary outcomes included ease, time, and success of SGA insertion; success of intubation on first attempt; overall intubation success; number of attempts to intubate; ease of intubation; and ease of SGA removals. RESULTS: One hundred and fifty patients were enrolled from March 2017 to January 2018. Median intubation times were similar across the three groups (Air-Q Blocker, 44 sec; AuraGain, 45 sec; i-gel, 36 sec; P = 0.08). The i-gel was faster to insert (i-gel: 10 sec; Air-Q Blocker, 16 sec; AuraGain, 16 sec; P < 0.001) and easier to insert (Air-Q Blocker vs i-gel, P = 0.001; AuraGain vs i-gel, P = 0.002). Success of SGA insertion, success of intubation, and number of attempts were similar. The Air-Q Blocker was easier to remove than the i-gel (P < 0.001). CONCLUSION: All three second-generation SGA devices performed similarly regarding intubation. Despite minor benefits of the i-gel, clinicians should select their SGA based on clinical experience. STUDY REGISTRATION: ClinicalTrials.gov (NCT02975466); registered on 29 November 2016.

RéSUMé: OBJECTIF: Une fois qu'une ventilation et une intubation difficiles sont déclarées, les lignes directrices préconisent le recours à un dispositif supraglottique comme modalité de sauvetage pour ventiler le patient et, si l'oxygénation est rétablie, être ensuite utilisé comme conduit d'intubation. Toutefois, peu d'études ont formellement analysé l'utilisation des dispositifs supraglottiques récents chez de véritbales patients. Notre objectif était de comparer l'efficacité de trois dispositifs supraglottiques de deuxième génération utilisés comme conduits pour l'intubation endotrachéale guidée par bronchoscopie. MéTHODE: Dans cette étude prospective randomisée contrôlée à trois bras et à simple insu, les patients de statut physique I-III selon l'American Society of Anesthesiologists bénéficiant d'une anesthésie générale ont été randomisés à recevoir une intubation endotrachéale guidée par bronchoscopie via les dispositifs AuraGain™, Air-Q® Blocker ou i-gel®. Nous avons exclu les patients présentant des contre-indications à l'utilisation d'un dispositif supraglottique ou aux médicaments, ainsi que les patientes enceintes et les patients présentant une anomalie au niveau du cou, de la colonne vertébrale ou des voies aériennes. Le critère d'évaluation principal était le temps d'intubation mesuré entre le moment de déconnexion du dispositif supraglottique du circuit et le moment de mesure du CO2. Les critères d'évaluation secondaires comprenaient la facilité, le délai et la réussite de l'insertion du dispositif supraglottique; la réussite de l'intubation à la première tentative; la réussite globale de l'intubation; le nombre de tentatives d'intubation; la facilité d'intubation; et la facilité de retrait du dispositif supraglottique. RéSULTATS: Cent cinquante patients ont été recrutés de mars 2017 à janvier 2018. Les délais d'intubation médians étaient similaires dans les trois groupes (Air-Q Blocker : 44 sec; AuraGain : 45 sec; i-gel : 36 sec; P = 0,08). L'i-gel était plus rapide à insérer (i-gel : 10 sec; Air-Q Blocker : 16 sec; AuraGain : 16 sec; P < 0,001) et plus facile à insérer (Air-Q Blocker vs i-gel : P = 0,001; AuraGain vs i-gel : P = 0,002). La réussite de l'insertion du dispositif supraglottique, la réussite de l'intubation et le nombre de tentatives étaient similaires. L'Air-Q Blocker était plus facile à retirer que l'i-gel (P < 0,001). CONCLUSION: Les trois dispositifs supraglottiques de deuxième génération ont tous affiché une performance similaire en matière d'intubation. Malgré des avantages mineurs de l'i-gel, les cliniciens devraient choisir leur dispositif supraglottique en fonction de leur expérience clinique. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT02975466); enregistrée le 29 novembre 2016.

A new machine learning algorithm to predict veno-arterial ECMO implantation after post-cardiotomy low cardiac output syndrome.

BACKGROUND: Post-cardiotomy low cardiac output syndrome (PC-LCOS) is a life-threatening complication after cardiac surgery involving a cardiopulmonary bypass (CPB). Mechanical circulatory support with veno-arterial membrane oxygenation (VA-ECMO) may be necessary in the case of refractory shock. The objective of the study was to develop a machine-learning algorithm to predict the need for VA-ECMO implantation in patients with PC-LCOS. PATIENTS AND METHODS: Patients were included in the study with moderate to severe PC-LCOS (defined by a vasoactive inotropic score (VIS) > 10 with clinical or biological markers of impaired organ perfusion or need for mechanical circulatory support after cardiac surgery) from two university hospitals in Paris, France. The Deep Super Learner, an ensemble machine learning algorithm, was trained to predict VA-ECMO implantation using features readily available at the end of a CPB. Feature importance was estimated using Shapley values. RESULTS: Between January 2016 and December 2019, 285 patients were included in the development dataset and 190 patients in the external validation dataset. The primary outcome, the need for VA-ECMO implantation, occurred respectively, in 16% (n = 46) and 10% (n = 19) in the development and the external validation datasets. The Deep Super Learner algorithm achieved a 0.863 (0.793-0.928) ROC AUC to predict the primary outcome in the external validation dataset. The most important features were the first postoperative arterial lactate value, intraoperative VIS, the absence of angiotensin-converting enzyme treatment, body mass index, and EuroSCORE II. CONCLUSIONS: We developed an explainable ensemble machine learning algorithm that could help clinicians predict the risk of deterioration and the need for VA-ECMO implantation in moderate to severe PC-LCOS patients.

Prediction of acute postoperative pain based on intraoperative nociception level (NOL) index values: the impact of machine learning-based analysis.

The relationship between intraoperative nociception and acute postoperative pain is still not well established. The nociception level (NOL) Index (Medasense, Ramat Gan, Israel) uses a multiparametric approach to provide a 0-100 nociception score. The objective of the ancillary analysis of the NOLGYN study was to evaluate the ability of a machine-learning aglorithm to predict moderate to severe acute postoperative pain based on intraoperative NOL values. Our study uses the data from the NOLGYN study, a randomized controlled trial that evaluated the impact of NOL-guided intraoperative administration of fentanyl on overall fentanyl consumption compared to standard of care. Seventy patients (ASA class I-III, aged 18-75 years) scheduled for gynecological laparoscopic surgery were enrolled. Variables included baseline demographics, NOL reaction to incision or intubation, median NOL during surgery, NOL time-weighted average (TWA) above or under manufacturers' recommended thresholds (10-25), and percentage of surgical time spent with NOL > 25 or < 10. We evaluated different machine learning algorithms to predict postoperative pain. Performance was assessed using cross-validated area under the ROC curve (CV-AUC). Of the 66 patients analyzed, 42 (63.6%) experienced moderate to severe pain. NOL post-intubation (42.8 (31.8-50.6) vs. 34.8 (25.6-41.3), p = 0.05), median NOL during surgery (13 (11-15) vs. 11 (8-13), p = 0.027), percentage of surgical time spent with NOL > 25 (23% (18-18) vs. 20% (15-24), p = 0.036), NOL TWA < 10 (2.54 (2.1-3.0) vs. 2.86 (2.48-3.62), p = 0.044) and percentage of surgical time spent with NOL < 10 (41% (36-47) vs. 47% (40-55), p = 0.022) were associated with moderate to severe PACU pain. Corresponding ROC AUC for the prediction of moderate to severe PACU pain were 0.65 [0.51-0.79], 0.66 [0.52-0.81], 0.66 [0.52-0.79], 0.65 [0.51-0.79] and 0.67 [0.53-0.81]. Penalized logistic regression achieved the best performance with a 0.753 (0.718-0.788) CV-AUC. Our results, even if limited by the small number of patients, suggest that acute postoperative pain is better predicted by a multivariate machine-learning algorithm rather than individual intraoperative nociception variables. Further larger multicentric trials are highly recommended to better understand the relationship between intraoperative nociception and acute postoperative pain.Trial registration Registered on ClinicalTrials.gov in October 2018 (NCT03776838).

Identification of the intraoperative antinociceptive effect of intravenous fentanyl using the Nociception Level (NOL) index versus clinical parameters in patients undergoing gynecological laparoscopic surgery: A secondary analysis of the NOLGYN study.

BACKGROUND: While we typically assess nociception balance during general anesthesia through clinical parameters such as heart rate (HR) and mean arterial pressure (MAP) variation, these parameters are not specific to nociception. OBJECTIVE: We hypothesized that using the Nociception Level (NOL) index to assess the analgesic effect of a fentanyl bolus would be superior to standard clinical parameters. DESIGN: Ancillary study of the NOLGYN study, a randomized controlled trial comparing intraoperative NOL-guided administration of fentanyl (NOL group) versus standardized care (SC group). SETTING: University hospital in Montréal, Canada between November 2018, and December 2019. PATIENTS: Women undergoing gynecological laparoscopic surgery. INTERVENTION: In our evaluation of intraoperative nociception, we analyzed the analgesic effect of fentanyl using three parameters: MAP, HR, and the Nociception Level (NOL) index. All fentanyl injection events were extracted from the database. MAIN OUTCOME MEASURE: The primary endpoint was the difference between values before and after each injection. RESULTS: The median of the NOL index before fentanyl injection was 30.5 (IQR 19.4 to 40.7) versus 18.9 (IQR 11.5 to 27.4) after (P < 0.001). The median of MAP was 106.4 mmHg (IQR 99.9 to 113.4) before injection versus 103.2 mmHg (IQR 97.5-110.7) after (P < 0.001). The median of HR before injection was 74.2 (IQR 64.2-83.8) versus 72.4 (IQR 63.4-81.3) after (P < 0.001). CONCLUSIONS: The NOL index, HR, and MAP all statistically discriminated the analgesic effect of fentanyl but only the NOL index proved clinically relevant to identify the analgesic effect of one fentanyl injection. TRIAL REGISTRATION: www. CLINICALTRIALS: gov (NCT03776838) registered in October 2018.

Effect of electroencephalography-guided anesthesia on neurocognitive disorders in elderly patients undergoing major non-cardiac surgery: A trial protocol The POEGEA trial (POncd Elderly GEneral Anesthesia).

INTRODUCTION: The number of elderly patients undergoing major surgery is rapidly increasing. They are particularly at risk of developing postoperative neurocognitive disorders (NCD). Earlier studies suggested that processed electroencephalographic (EEG) monitors may reduce the incidence of postoperative NCD. However, none of these studies controlled for intraoperative nociception levels or personalized blood pressure targets. Their results remain unclear if the reduction in the incidence of postoperative NCD relates to avoidance of any electroencephalographic pattern suggesting excessive anesthesia depth. OBJECTIVE: The objective of this trial is to investigate-in patients ≥ 70 years old undergoing major non-cardiac surgery-the effect of EEG-guided anesthesia on postoperative NCD while controlling for intraoperative nociception, personalized blood pressure targets, and using detailed information provided by the EEG monitor (including burst suppression ratio, density spectral array, and raw EEG waveform). MATERIAL AND METHODS: This prospective, randomized, controlled trial will be conducted in a single Canadian university hospital. Patients ≥ 70 years old undergoing elective major non-cardiac surgery will be included in the trial. The administration of sevoflurane will be adjusted to maintain a BIS index value between 40 and 60, to keep a Suppression Ratio (SR) at 0%, to keep a direct EEG display without any suppression time and a spectrogram with most of the EEG wave frequency within the alpha, theta, and delta frequencies in the EEG-guided group. In the control group, sevoflurane will be administered to achieve an age-adjusted minimum alveolar concentration of [0.8-1.2]. In both groups, a nociception monitor will guide intraoperative opioid administration, individual blood pressure targets will be used, and cerebral oximetry used to tailor intraoperative hemodynamic management. The primary endpoint will be the incidence of NCD at postoperative day 1, as evaluated by the Montreal Cognitive Assessment (MoCA). Secondary endpoints will include the incidence of postoperative NCD at different time points and the evaluation of cognitive trajectories up to 90 days after surgery among EEG-guided and control groups. STUDY REGISTRATION: NCT04825847 on ClinicalTrials.gov.

Retroclavicular vs Infraclavicular block for brachial plexus anesthesia: a multi-centric randomized trial.

BACKGROUND: The coracoid approach is a simple method to perform ultrasound-guided brachial plexus regional anesthesia (RA) but its simplicity is counterbalanced by a difficult needle visualization. We hypothesized that the retroclavicular (RCB) approach is not longer to perform when compared to the coracoid (ICB) approach, and improves needle visualization. METHODS: This randomized, controlled, non-inferiority trial conducted in two hospitals, included patients undergoing distal upper limb surgery. Patients were randomly assigned to a brachial plexus block (ICB or RCB). The primary outcome was performance time (sum of visualization and needling time), and was analyzed with a non-inferiority test of averages. Depth of sensory and motor blockade, surgical success, total anesthesia time, needle visualization, number of needle passes and complications were also evaluated. Subgroup analysis restricted to patients with higher body mass index was completed. RESULTS: We included 109 patients between September 2016 and May 2017. Mean RCB performance time was 4.8 ± 2.0 min while ICB was 5.2 ± 2.3 min (p = 0.06) with a 95% CI reaching up to 5.8% longer. RCB conferred an ultrasound-needle angle closer to 0° and significantly improved needle visibility after the clavicle was cleared and before local anesthetic administration. No differences were found in the secondary outcomes. Similar results were found in the subgroup analysis. CONCLUSION: RCB approach for brachial plexus anesthesia was similar to ICB approach in terms of time performance. Needle visibility, which represent an important clinical variable, was superior and angle between needle and ultrasound probe was close to 0° in the RCB group. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT02913625), registered 26 September 2016.