Identifying intraoperative events in a simulated laparotomy video: a multinational study of inattentional blindness among anesthesiologists.

PURPOSE: Medical errors may be occasionally explained by inattentional blindness (IB), i.e., failing to notice an event/object that is in plain sight. We aimed to determine whether age/experience, restfulness/fatigue, and previous exposure to simulation education may affect IB in the anesthetic/surgical setting. METHODS: In this multicentre/multinational study, a convenience sample of 280 anesthesiologists watched an attention-demanding video of a simulated trauma patient undergoing laparotomy and (independently/anonymously) recorded the abnormalities they noticed. The video contained four expected/common abnormalities (hypotension, tachycardia, hypoxia, hypothermia) and two prominently displayed unexpected/rare events (patient's head movement, leaky central venous line). We analyzed the participants' ability to notice the expected/unexpected events (primary outcome) and the proportion of expected/unexpected events according to age group and prior exposure to simulation education (secondary outcomes). RESULTS: Anesthesiologists across all ages noticed fewer unexpected/rare events than expected/common ones. Overall, younger anesthesiologists missed fewer common events than older participants did (P = 0.02). There was no consistent association between age and perception of unexpected/rare events (P = 0.28), although the youngest cohort (< 30 yr) outperformed the other age groups. Prior simulation education did not affect the proportion of misses for the unexpected/rare events but was associated with fewer misses for the expected/common events. Self-perceived restfulness did not impact perception of events. CONCLUSION: Anesthesiologists noticed fewer unexpected/rare clinical events than expected/common ones in an attention-demanding video of a simulated trauma patient, in keeping with IB. Prior simulation training was associated with an improved ability to notice anticipated/expected events, but did not reduce IB. Our findings may have implications for understanding medical mishaps, and efforts to improve situational awareness, especially in acute perioperative and critical care settings.

RéSUMé: OBJECTIF: Les erreurs médicales peuvent parfois s'expliquer par la cécité d'inattention, soit le fait de ne pas remarquer un événement/objet qui est à la vue de tous et toutes. Notre objectif était de déterminer si l'âge/l'expérience, le repos/la fatigue et l'exposition antérieure à l'enseignement par simulation pouvaient affecter la cécité d'inattention dans le cadre de l'anesthésie/chirurgie. MéTHODE: Dans cette étude multicentrique/multinationale, un échantillon de convenance de 280 anesthésiologistes ont visionné une vidéo exigeant l'attention portant sur un patient de trauma simulé bénéficiant d'une laparotomie et ont enregistré (de manière indépendante/anonyme) les anomalies qu'ils et elles ont remarquées. La vidéo contenait quatre anomalies attendues/courantes (hypotension, tachycardie, hypoxie, hypothermie) et deux événements inattendus/rares bien en vue (mouvement de la tête du patient, fuite du cathéter veineux central). Nous avons analysé la capacité des participant·es à remarquer les événements attendus/inattendus (critère d'évaluation principal) et la proportion d'événements attendus/inattendus selon le groupe d'âge et l'exposition antérieure à l'enseignement par simulation (critères d'évaluation secondaires). RéSULTATS: Les anesthésiologistes de tous âges ont remarqué moins d'événements inattendus/rares que d'événements attendus/courants. Globalement, les anesthésiologistes plus jeunes ont manqué moins d'événements courants que leurs congénères plus âgé·es (P = 0,02). Il n'y avait pas d'association constante entre l'âge et la perception d'événements inattendus ou rares (P = 0,28), bien que la cohorte la plus jeune (< 30 ans) ait surpassé les autres groupes d'âge. La formation antérieure par simulation n'a pas eu d'incidence sur la proportion d'inobservation des événements inattendus ou rares, mais a été associée à moins de cécité d'inattention envers les événements attendus ou courants. Le repos perçu n'a pas eu d'impact sur la perception des événements. CONCLUSION: Les anesthésiologistes ont remarqué moins d'événements cliniques inattendus/rares que d'événements attendus/courants dans une vidéo exigeant l'attention portant sur la simulation d'un patient traumatisé, ce qui s'inscrit dans la cécité d'inattention. La formation préalable par simulation était associée à une meilleure capacité à remarquer les événements anticipés/attendus, mais ne réduisait pas la cécité d'inattention. Nos résultats peuvent avoir des implications pour la compréhension des accidents médicaux et les efforts visant à améliorer la conscience situationnelle, en particulier dans les contextes de soins périopératoires aigus et de soins intensifs.

Analgesia for rib fractures: a narrative review.

PURPOSE: Rib fracture(s) is a common and painful injury often associated with significant morbidity (e.g., respiratory complications) and high mortality rates, especially in the elderly. Risk stratification and prompt implementation of analgesic pathways using a multimodal analgesia approach comprise a primary endpoint of care to reduce morbidity and mortality associated with rib fractures. This narrative review aims to describe the most recent evidence and care pathways currently available, including risk stratification tools and pharmacologic and regional analgesic blocks frequently used as part of the broadly recommended multimodal analgesic approach. SOURCE: Available literature was searched using PubMed and Embase databases for each topic addressed herein and reviewed by content experts. PRINCIPAL FINDINGS: Four risk stratification tools were identified, with the Study of the Management of Blunt Chest Wall Trauma score as most predictive. Current evidence on pharmacologic (i.e., acetaminophen, nonsteroidal anti-inflammatory drugs, gabapentinoids, ketamine, lidocaine, and dexmedetomidine) and regional analgesia (i.e., thoracic epidural analgesia, thoracic paravertebral block, erector spinae plane block, and serratus anterior plane block) techniques was reviewed, as was the pathophysiology of rib fracture(s) and its associated complications, including the development of chronic pain and disabilities. CONCLUSION: Rib fracture(s) continues to be a serious diagnosis, with high rates of mortality, development of chronic pain, and disability. A multidisciplinary approach to management, combined with appropriate analgesia and adherence to care bundles/protocols, has been shown to decrease morbidity and mortality. Most of the risk-stratifying care pathways identified perform poorly in predicting mortality and complications after rib fracture(s).

RéSUMé: OBJECTIF: Les fractures des côtes sont des blessures courantes et douloureuses souvent associées à une morbidité importante (p. ex., complications respiratoires) et à des taux de mortalité élevés, surtout chez les personnes âgées. La stratification des risques et la mise en œuvre rapide de voies analgésiques à l'aide d'une approche d'analgésie multimodale constituent un critère d'évaluation principal des soins visant à réduire la morbidité et la mortalité associées aux fractures des côtes. Ce compte rendu narratif a pour objectif de décrire les données probantes les plus récentes et les parcours de soins actuellement disponibles, y compris les outils de stratification des risques et les blocs analgésiques pharmacologiques et régionaux fréquemment utilisés dans le cadre de l'approche analgésique multimodale largement recommandée. SOURCES: La littérature disponible a été recherchée à l'aide des bases de données PubMed et Embase pour chaque sujet abordé dans le présent compte rendu et examinée par des expert·es en contenu. CONSTATATIONS PRINCIPALES: Quatre outils de stratification des risques ont été identifiés, le score de l'Étude de la prise en charge des traumatismes contondants de la paroi thoracique (Study of the Management of Blunt Chest Wall Trauma) étant le plus prédictif. Les données probantes actuelles sur les techniques d'analgésie pharmacologiques (c.-à-d. acétaminophène, anti-inflammatoires non stéroïdiens, gabapentinoïdes, kétamine, lidocaïne et dexmédétomidine) et d'analgésie régionale (c.-à-d. analgésie péridurale thoracique, bloc paravertébral thoracique, bloc du plan des muscles érecteurs du rachis et bloc du plan du muscle grand dentelé) ont été examinées, de même que la physiopathologie de la ou des fractures des côtes et de leurs complications associées, y compris l'apparition de douleurs chroniques et d'incapacités. CONCLUSION: Les fractures des côtes continuent d'être un diagnostic grave, avec des taux élevés de mortalité, de développement de douleurs chroniques et d'invalidité. Il a été démontré qu'une approche multidisciplinaire de la prise en charge, combinée à une analgésie appropriée et à l'adhésion aux ensembles et protocoles de soins, réduit la morbidité et la mortalité. La plupart des parcours de soins de stratification des risques identifiés sont peu performants pour prédire la mortalité et les complications après une ou plusieurs fractures de côtes.

Introducing the fragility index-A case study using the Term Breech Trial.

The fragility index (FI) is a sensitivity analysis of the statistically significant result of a clinical study. It is the number of hypothetical changes in the primary event of one of the two cohorts in a 1-to-1 comparative trial to render the statistically significant result non-significant (ie, to alter the P-value from ≤0.05 to >0.05). The FI can be compared with the patient drop-out rates and protocol violations, which, if much higher than the FI, may arguably suggest less robustness/stability of the trial's results. To illustrate the concept, we have chosen the Term Breech Trial (TBT) as a case study. The TBT results favor planned cesarean birth, as opposed to planned vaginal delivery, in the term singleton fetus with breech presentation. Our analysis shows that the FI of the TBT is 21, which is small in comparison to the number (hundreds) of protocol violations present. Some experts have suggested the inclusion of the FI in data analysis and subsequent discussion of clinical trial data. Routine use of such a metric may be valuable in encouraging readers to maintain a healthy degree of skepticism, especially when interpreting trial results which may directly influence clinical practice.

Immune-Related Adverse Events Associated With Immune Checkpoint Inhibitor Therapy.

As part of immune surveillance, killer T lymphocytes search for cancer cells and destroy them. Some cancer cells, however, develop escape mechanisms to evade detection and destruction. One of these mechanisms is the expression of cell surface proteins which allow the cancer cell to bind to proteins on T cells called checkpoints to switch off and effectively evade T-cell-mediated destruction. Immune checkpoint inhibitors (ICIs) are antibodies that block the binding of cancer cell proteins to T-cell checkpoints, preventing the T-cell response from being turned off by cancer cells and enabling killer T cells to attack. In other words, ICIs restore innate antitumor immunity, as opposed to traditional chemotherapies that directly kill cancer cells. Given their relatively excellent risk-benefit ratio when compared to other forms of cancer treatment modalities, ICIs are now becoming ubiquitous and have revolutionized the treatment of many types of cancer. Indeed, the prognosis of some patients is so much improved that the threshold for admission for intensive care should be adjusted accordingly. Nevertheless, by modulating immune checkpoint activity, ICIs can disrupt the intricate homeostasis between inhibition and stimulation of immune response, leading to decreased immune self-tolerance and, ultimately, autoimmune complications. These immune-related adverse events (IRAEs) may virtually affect all body systems. Multiple IRAEs are common and may range from mild to life-threatening. Management requires a multidisciplinary approach and consists mainly of immunosuppression, cessation or postponement of ICI treatment, and supportive therapy, which may require surgical intervention and/or intensive care. We herein review the current literature surrounding IRAEs of interest to anesthesiologists and intensivists. With proper care, fatality (0.3%-1.3%) is rare.

Immune Checkpoint Inhibitor-Mediated Myasthenia Gravis.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have a wide range of toxicities affecting potentially any organ system stemming from increased activity within the T-cell lineage similar to that observed in autoimmunity. CASE REPORT: A 57-year-old man with metastatic papillary renal cell carcinoma treatment with combination ICI therapy presented with a history of rapidly progressive diplopia. Neurological examination revealed bilateral fatigable ptosis and asymmetrical ophthalmoplegia. His clinical findings were in keeping with an immune-mediated myasthenia gravis. He was immediately commenced on 1 mg/kg of intravenous methylprednisolone and pyridostigmine 60 mg 3 times a day. On day 2 of admission he was given 1 g/kg of intravenous immunoglobulins. He made a rapid and full clinical recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Immune-mediated myasthenia gravis is an important toxicity of ICIs. Early recognition and treatment of this presentation may reduce the significant morbidity and mortality associated with it.

Computer simulation of transfusion with different blood product ratios in modern massive transfusion protocols.

Modern massive transfusion protocols call for early plasma and platelets to patients presenting with hemorrhagic shock. The packed red blood cell (PRBC):plasma:platelet ratio generally ranges from 1:1:1 to 3:1:1, but the ideal ratio remains controversial. We aimed to determine the effects of different resuscitation strategies and blood product ratios on hematocrit, platelet and fibrinogen concentrations (FC) during resuscitation. Assuming: pre-insult blood volume 5 L; hematocrit 0.4, FC = 100%, platelet count 400 × 109/L; predetermined constant values for each blood product unit (volume, hematocrit, FC, platelet number); and transfusion rate to maintain euvolemia, we simulated different resuscitation strategies using a computer-based hemorrhage model. When crystalloids are administered to restore an acute 30% blood loss, the initial hematocrit, platelets and FC are adequate, and remain physiologic when further resuscitation is carried out with 1:1:1. Higher transfusion ratios increase the hematocrit at the expense of proportional drops in FC and platelets. When crystalloids and PRBCs (1500 mL) are administered to restore an acute 60% blood loss, the FC drops to 39%. Further resuscitation with 1:1:1 (but not with 2:1:1 or 3:1:1) increases the FC while maintaining the hematocrit and platelets within physiologic range. When blood products (1-3:1:1) are administered to restore an acute 60% blood loss, the initial hematocrit, platelets and FC are at adequate levels, but remain within physiologic range only when 1:1:1 (but not 2:1:1 or 3:1:1) is implemented for further resuscitation. Notably, platelet concentration consistently drops in all simulated scenarios reaching dangerously low levels particularly with high blood loss/transfusion rates and with higher transfusion ratios. The FC does not always drop by the same proportion with higher ratios probably because it is based on plasma concentration and is thus "cushioned" by the reduction in plasma volume as the hematocrit rises with higher transfusion ratios. In summary, computer simulation suggests that in non-severe shock hemorrhage, the differences between 1-3:1:1 transfusion ratios during initial resuscitation may be small. In severe shock, however, 1:1:1 results in the most physiologic hematocrit, FC and platelet concentration and is, therefore, desirable.

Tracheal Intubation: The Proof is in the Bevel.

BACKGROUND: Efficient airway management is paramount in emergency medicine. Our experience teaching tracheal intubation has consistently identified gaps in the understanding of important issues. Here we discuss the importance of the endotracheal tube (ETT) bevel in airway management. DISCUSSION: The ETT bevel orientation is the main determinant of which mainstem bronchus the ETT enters when advanced too distally, despite a common belief that attributes a higher incidence of right mainstem bronchial intubation to the straighter angle sustained by the right mainstem bronchus. Likewise, a bougie- or fiberscope-assisted tracheal intubation can be impeded by the ETT tip hooking onto laryngeal structures; a 90-degree counterclockwise turn of the ETT (such that the bevel is facing posteriorly) prior to advancing it toward the larynx produces a first-pass success rate of 100%. Similarly, a posterior-facing bevel is believed to improve the ease of passage through the back of the nasal cavity when performing nasotracheal intubation. If resistance is met after the ETT tip has reached the laryngeal vicinity, further counterclockwise rotation may change the plane and incident angle of the ETT tip, facilitating passage through the vocal cords. Clockwise twisting of the ETT reduces the incident angle in the sagittal plane, thereby facilitating videolaryngoscopy-assisted tracheal intubation. Finally, a posterior-facing ETT bevel is the least likely to intubate a tracheoesophageal fistula. CONCLUSIONS: Understanding the implications of the ETT bevel direction may significantly change the efficiency of deliberate endobronchial, nasal, and bougie/fiberscope-, and videolaryngoscope-assisted intubations, and while managing the patient with a tracheoesophageal fistula.

Bias in Before-After Studies: Narrative Overview for Anesthesiologists.

Before-after study designs are effective research tools and in some cases, have changed practice. These designs, however, are inherently susceptible to bias (ie, systematic errors) that are sometimes subtle but can invalidate their conclusions. This overview provides examples of before-after studies relevant to anesthesiologists to illustrate potential sources of bias, including selection/assignment, history, regression to the mean, test-retest, maturation, observer, retrospective, Hawthorne, instrumentation, attrition, and reporting/publication bias. Mitigating strategies include using a control group, blinding, matching before and after cohorts, minimizing the time lag between cohorts, using prospective data collection with consistent measuring/reporting criteria, time series data collection, and/or alternative study designs, when possible. Improved reporting with enforcement of the Enhancing Quality and Transparency of Health Research (EQUATOR) checklists will serve to increase transparency and aid in interpretation. By highlighting the potential types of bias and strategies to improve transparency and mitigate flaws, this overview aims to better equip anesthesiologists in designing and/or critically appraising before-after studies.

Cannula malposition during antegrade cerebral perfusion for aortic surgery: role of cerebral oximetry.

PURPOSE: To describe the use of cerebral oximetry to detect a lack of right cerebral perfusion resulting from a malpositioned catheter used for antegrade cerebral perfusion during deep hypothermic circulatory arrest (DHCA). The simple corrective surgical adjustment that followed averted a potentially serious complication. CLINICAL FEATURES: A 57-yr-old male with a type-A aortic dissection undergoing DHCA required antegrade cerebral perfusion for cerebral protection. Catheters were placed accordingly in the left common carotid and brachiocephalic arteries. Whereas frontal cerebral oximetry immediately improved on the left, it did not improve on the right. It was immediately suspected that the tip of the brachiocephalic cannula had advanced into the right subclavian artery, thus depriving the right common carotid artery of blood flow. The problem resolved upon slight withdrawal of the cannula. CONCLUSION: Vigilance in anesthesia should not stop during DHCA or cardiopulmonary bypass. Cerebral oximetry may provide important information leading to actions that improve brain protection. Vigilances proved important in this case where the cannula tip used for antegrade cerebral perfusion was advanced too far into the right subclavian artery.

The medial-transverse approach for internal jugular vein cannulation: an example of lateral thinking.

BACKGROUND: Cannulation of the internal jugular vein (IJV) is traditionally performed using the central-longitudinal approach. Pneumothorax, carotid artery puncture, and failure to cannulate are uncommon, but by no means rare, complications. Ultrasound (US) guidance for IJV cannulation has reduced but not eliminated such complications. TECHNIQUE: We herein introduce a new approach, coined the "medial-transverse approach" due to the perpendicular angle at which the introducer needle is advanced toward the IJV from the median to lateral direction. DISCUSSION: The direction of the introducer needle is not toward the lung, thus virtually eliminating the possibility of pneumothorax. The image of the entire needle is seen when the US probe is typically orientated for a short-axis view of the IJV and carotid artery, thus improving the chance of uncomplicated IJV puncture. We have used this technique with apparent success in thousands of cases over the past 20 years in two different institutions. CONCLUSION: A modified IJV cannulation technique that seems to have unique advantages over traditional approaches has been described. This technique is compatible with the blind and US-guided approaches.