Characterizing the Relationship Between Arterial Carbon Dioxide Trajectory and Serial Brain Biomarkers with Central Nervous System Injury During Veno-Venous Extracorporeal Membrane Oxygenation: A Prospective Cohort Study.

BACKGROUND: Central nervous system (CNS) injury following initiation of veno-venous extracorporeal membrane oxygenation (VV-ECMO) is common. An acute decrease in partial pressure of arterial carbon dioxide (PaCO2) following VV-ECMO initiation has been suggested as an etiological factor, but the challenges of diagnosing CNS injuries has made discerning a relationship between PaCO2 and CNS injury difficult. METHODS: We conducted a prospective cohort study of adult patients undergoing VV-ECMO for acute respiratory failure. Arterial blood gas measurements were obtained prior to initiation of VV-ECMO, and at every 2-4 h for the first 24 h. Neuroimaging was conducted within the first 7-14 days in patients who were suspected of having neurological injury or unable to be examined because of sedation. We collected blood biospecimens to measure brain biomarkers [neurofilament light (NF-L); glial fibrillary acidic protein (GFAP); and phosphorylated-tau 181] in the first 7 days following initiation of VV-ECMO. We assessed the relationship between both PaCO2 over the first 24 h and brain biomarkers with CNS injury using mixed methods linear regression. Finally, we explored the effects of absolute change of PaCO2 on serum levels of neurological biomarkers by separate mixed methods linear regression for each biomarker using three PaCO2 exposures hypothesized to result in CNS injury. RESULTS: In our cohort, 12 of 59 (20%) patients had overt CNS injury identified on head computed tomography. The PaCO2 decrease with VV-ECMO initiation was steeper in patients who developed a CNS injury (- 0.32%, 95% confidence interval - 0.25 to - 0.39) compared with those without (- 0.18%, 95% confidence interval - 0.14 to - 0.21, P interaction < 0.001). The mean concentration of NF-L increased over time and was higher in those with a CNS injury (464 [739]) compared with those without (127 [257]; P = 0.001). GFAP was higher in those with a CNS injury (4278 [11,653] pg/ml) compared with those without (116 [108] pg/ml; P < 0.001). The mean NF-L, GFAP, and tau over time in patients stratified by the three thresholds of absolute change of PaCO2 showed no differences and had no significant interaction for time. CONCLUSIONS: Although rapid decreases in PaCO2 following initiation of VV-ECMO were slightly greater in patients who had CNS injuries versus those without, data overlap and absence of relationships between PaCO2 and brain biomarkers suggests other pathophysiologic variables are likely at play.

Extracorporeal life support in trauma: Indications and techniques.

BACKGROUND: Clarity about indications and techniques in extracorporeal life support (ECLS) in trauma is essential for timely and effective deployment, and to ensure good stewardship of an important resource. Extracorporeal life support deployments in a tertiary trauma center were reviewed to understand the indications, strategies, and tactics of ECLS in trauma. METHODS: The provincial trauma registry was used to identify patients who received ECLS at a Level I trauma center and ECLS organization-accredited site between January 2014 and February 2021. Charts were reviewed for indications, technical factors, and outcomes following ECLS deployment. Based on this data, consensus around indications and techniques for ECLS in trauma was reached and refined by a multidisciplinary team discussion. RESULTS: A total of 25 patients underwent ECLS as part of a comprehensive trauma resuscitation strategy. Eighteen patients underwent venovenous ECLS and seven received venoarterial ECLS. Nineteen patients survived the ECLS run, of which 15 survived to discharge. Four patients developed vascular injuries secondary to cannula insertion while four patients developed circuit clots. On multidisciplinary consensus, three broad indications for ECLS and their respective techniques were described: gas exchange for lung injury, extended damage control for severe injuries associated with the lethal triad, and circulatory support for cardiogenic shock or hypothermia. CONCLUSION: The three broad indications for ECLS in trauma (gas exchange, extended damage control and circulatory support) require specific advanced planning and standardization of corresponding techniques (cannulation, circuit configuration, anticoagulation, and duration). When appropriately and effectively integrated into the trauma response, ECLS can extend the damage control paradigm to enable the management of complex multisystem injuries. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Fatal cerebral air embolism post esophageal endoscopy with dilatation: A case report.

This is a case of a patient who underwent an esophageal dilatation for benign esophageal strictures. As a consequence of the procedure, she developed an esophageal rupture and multiple cerebral and cerebellar air emboli resulting in infarction. The patient died after being placed on comfort care measures. The postmortem examination revealed focal breach of the esophageal mucosa but no sites of cardiac or vascular shunting that could account for the transit of air from the esophagus to the central nervous system. The phenomenon of vascular air entry as a consequence of upper gastrointestinal endoscopic intervention is an uncommon but very serious complication of balloon dilatation therapy. Instances of progression to intracranial arterial gas embolism are even less common, but are well described in a small number of case reports. We present a fatal case of central nervous system air embolism post-balloon dilatation therapy with associated antemortem imaging, autopsy, and microscopic images followed by a discussion of potential mechanisms of entry of air into the brain.

Seventy-seven days on veno-venous extracorporeal membrane oxygenation for severe acute respiratory distress syndrome from SARS-CoV-2.

Throughout the COVID-19 pandemic veno-venous extracorporeal membrane oxygenation (VV ECMO) has emerged as a valid supportive intervention for severe COVID-19 pneumonia. In this report we describe the use of prolonged ECMO (77 days) to support a patient with COVID-19, ultimately resulting in lung recovery and discharge home. This report also emphasizes the value of physiotherapy in patients on ECMO and the importance of collaboration between ECMO programs and lung transplant teams in the care of these patients.

Lung Transplantation for COVID-19 Acute Respiratory Distress Syndrome: The British Columbian Experience With New Disease Pathology.

Lung transplantation is a life-saving treatment for patients with end-stage lung disease. COVID-19 has been associated with a severe and rapid decline in pulmonary function, in which case lung transplantation has been described to be effective. We herein describe 9 patients who underwent lung transplantation for COVID-19 acute respiratory distress syndrome, of whom 6 were bridged with extracorporeal membrane oxygenation (ECMO). The median time of pre-operative observation periods was 54 days to ensure no lung function recovery and the time to wean off extracorporeal membrane oxygenation was 3 days. Patients had comparable short-term survival outcomes to non-COVID-19 lung transplant recipients at our institution during the same time period. Lung transplantation for COVID-19-associated lung disease is feasible with comparable short-term outcomes and may liberate patients from extracorporeal supports.

Vancouver General Hospital Pulmonary Embolism Response Team (VGH PERT): initial three-year experience.

PURPOSE: Clinical equipoise exists with the use of novel reperfusion therapies such as catheter-directed thrombolysis in the management of patients presenting to hospital with high risk pulmonary embolism (PE). Therapeutic options rely on clinical presentation, patient factors, physician preference, and institutional availability. We established a Pulmonary Embolism Response Team (PERT) to provide urgent assessment and multidisciplinary care for patients presenting to our institution with high-risk PE. METHODS: Data were retrospectively collected from PERT activations between January 2016 and December 2018. Chi square tests were used to determine differences in mortality across the three years of study. Logistic regression was used to evaluate 30- and 90-day mortality and occurrence of major bleeds between those receiving anticoagulation alone (AC) and those receiving advanced reperfusion therapy (ART). RESULTS: There were 128 PERT activations over three years, the majority originating from the emergency department. Eighty-five percent of activations were for submassive PE, with 56% of all activations assessed as submassive-high risk. Fifteen patients (12%) presented with massive PE. Advanced reperfusion therapy was used in 29 (23%) patients, of whom 25 (20%) received catheter-directed thrombolysis. There was an increased risk of major bleeding in the ART group compared with in the AC group (odds ratio [OR], 17.9; 95% confidence interval [CI], 4.1 to 125.0; P < 0.001), but no increased risk of mortality at 30 days (OR, 2.1; 95% CI, 0.4 to 9.1; P = 0.3). The 30-day mortality rate was 7.8%. CONCLUSION: We describe the first Canadian PERT, a multidisciplinary team aimed at providing urgent individualized care for patients with high-risk PE. Further research is necessary to determine whether a PERT improves clinical outcomes.

RéSUMé: OBJECTIF: Le concept d'équilibre clinique existe lors de l'utilisation de traitements innovants de reperfusion tels que la thrombolyse in situ (ou thrombolyse par cathéter) pour la prise en charge des patients se présentant à l'hôpital avec une embolie pulmonaire (EP) à haut risque. Les options thérapeutiques s'appuient sur la présentation clinique, les caractéristiques du patient, la préférence du médecin et la disponibilité institutionnelle. Nous avons mis sur pied une Équipe d'intervention en cas d'embolie pulmonaire (PERT - Pulmonary Embolism Response Team) afin de fournir une évaluation urgente et des soins multidisciplinaires aux patients se présentant dans notre institution avec une EP à haut risque. MéTHODE: Nous avons récolté rétrospectivement les données concernant les activations/alertes reçues par notre PERT entre janvier 2016 et décembre 2018. Des tests de chi carré ont été utilisés afin de déterminer les différences en matière de mortalité au cours des trois années de durée de l'étude. La régression logistique a été utilisée pour évaluer la mortalité à 30 et à 90 jours ainsi que la survenue de saignements majeurs entre les patients recevant uniquement un traitement anticoagulant (AC) et ceux recevant un traitement de reperfusion avancé (TRA). RéSULTATS: Il y a eu 128 alertes requérant l'activation de notre PERT en trois ans, la majorité provenant de l'urgence. Quatre-vingt-cinq pour cent des activations concernaient des EP submassives, et 56 % de toutes les activations ont été évaluées comme étant submassives à haut risque. Quinze patients (12 %) se sont présentés avec une EP massive. Un traitement de reperfusion avancé a été administré à 29 (23 %) patients, parmi lesquels 25 (20 %) ont reçu une thrombolyse in situ. Un risque accru de saignement majeur a été observé dans le groupe TRA par rapport au groupe AC (rapport de cotes [RC], 17,9; intervalle de confiance [IC] 95 %, 4,1 à 125,0; P < 0,001), mais il n'y avait pas de risque accru de mortalité à 30 jours (RC, 2,1; IC 95 %, 0,4 à 9,1; P = 0,3). Le taux de mortalité à 30 jours était de 7,8 %. CONCLUSION: Nous décrivons la première PERT canadienne, une équipe multidisciplinaire ayant pour but de prodiguer des soins personnalisés urgents aux patients avec embolie pulmonaire à haut risque. Des recherches supplémentaires sont nécessaires pour déterminer si une PERT améliore les pronostics cliniques.

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for emergency cardiac support.

PURPOSE: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) may provide benefit to patients in refractory cardiac arrest and cardiogenic shock. We aim to summarize our center's 6-year experience with resuscitative VA-ECMO. MATERIALS AND METHODS: A retrospective medical record review (April 2009 to 2015) was performed on consecutive non-cardiotomy patients who were managed with VA-ECMO due to refractory in- or out-of-hospital cardiac (IHCA/OHCA) arrest (E-CPR) or refractory cardiogenic shock (E-CS) with or without preceding cardiac arrest. Our primary outcome was survival to hospital discharge and good neurological status (Cerebral Performance Category 1-2). RESULTS: There were a total of 22 patients who met inclusion criteria of whom 9 received E-CPR (8 IHCA, 1 OHCA) and 13 received E-CS. The median age for E-CPR patients was 52 [IQR 45, 58] years, and 54 [IQR 38, 64] years for E-CS patients. Cardiac arrest duration was 70.33 (SD 39.56) min for the E-CPR patients, and 24.67 (SD 26.73) min for the 9 patients treated with E-CS who had previously arrested. Initial cardiac arrest rhythms were pulseless electrical activity (39%), ventricular fibrillation (33%), or ventricular tachycardia (28%). A total of 18/22 patients were successfully weaned from VA-ECMO (78%); 16 patients survived to hospital discharge (73%) with 15 in good neurological condition. CONCLUSION: The initiation of VA-ECMO at our center for treatment of refractory cardiac arrest and cardiogenic shock yielded a high proportion of survivors and favorable neurological outcomes.

Early veno-venous extracorporeal membrane oxygenation is associated with lower mortality in patients who have severe hypoxemic respiratory failure: A retrospective multicenter cohort study.

PURPOSE: The purpose of the study is to compare outcomes in patients who had severe hypoxemic respiratory failure (Pao2/fraction of inspired oxygen <100) who received early veno-venous extracorporeal membrane oxygenation (ECMO) as an adjunct to mechanical ventilation, to those in patients who received conventional mechanical ventilation alone. MATERIALS AND METHODS: This is a multicenter, retrospective unmatched and matched cohort study of patients admitted between April 2006 and December 2013. Generalized logistic mixed-effects models and Cox proportional hazards models were used to determine the association between treatment with ECMO that was started within 3 days of intensive care unit (ICU) admission and ICU and hospital mortality and length of stay, respectively. RESULTS: A total of 2440 patients who had severe hypoxemic respiratory failure due to various etiologies were included, 46 who received early veno-venous ECMO and 2394 unmatched and 398 matched controls who received conventional ventilation alone. Compared to matched controls, ECMO was associated with a lower odds of ICU (odds ratio [95% confidence interval], 0.30 [0.13-0.67]) and inhospital death (odds ratio 0.30 [0.14-0.67]). In addition, ECMO was associated with longer times to discharge from ICU and hospital (hazard ratio, 0.42 [0.37-0.47] and 0.53 [0.38-0.73], respectively). CONCLUSIONS: In this observational study, use of early ECMO compared to conventional mechanical ventilation alone in patients who had severe hypoxemic respiratory failure was associated with a lower risk of mortality and a longer length of stay.

Canadian recommendations for critical care ultrasound training and competency.

OBJECTIVE: To achieve national consensus on standards of training, quality assurance and maintenance of competence for critical care ultrasound for intensivists and critical care trainees in Canada using recently published international training statements. DATA SOURCES: Existing internationally endorsed guidelines and expert opinion. DATA SYNTHESIS: In November 2013, a day-long consensus meeting was held with 15 Canadian experts in critical care ultrasound in which essential topics relevant to training ultrasound were discussed. CONCLUSIONS: Consensus was achieved to direct training curriculum, oversight, quality assurance and maintenance of competence for critical care ultrasound. In providing the first national guideline of its kind, these Canadian recommendations may also serve as a model of critical care ultrasound dissemination for other countries.

Anesthetic considerations for airway stenting in adult patients.

The attributable morbidity from central airway obstruction is significant. Airway stenting provides a therapeutic option to manage these complex lesions. This article focuses on the relevant anesthetic considerations of airway stenting in adult patients.

Intraoperative contralateral tension pneumothorax during pneumonectomy.

Unrecognized tension pneumothorax can have catastrophic consequences. We report a case of a patient who developed a contralateral tension pneumothorax during thoracotomy without the classic signs of marked hypoxemia and hemodynamic instability. A tension pneumothorax should be considered in any patient who develops high peak inspiratory pressures during one-lung ventilation with an open chest, even in the absence of the classic signs of hypoxemia and hypotension.