Background: Exposure to hyperoxia, a high arterial partial pressure of oxygen (PaO2), may be associated with worse outcomes in patients receiving extracorporeal membrane oxygenator (ECMO) support. We examined hyperoxia in the Extracorporeal Life Support Organization Registry among patients receiving venoarterial ECMO for cardiogenic shock. Methods: We included Extracorporeal Life Support Organization Registry patients from 2010 to 2020 who received venoarterial ECMO for cardiogenic shock, excluding extracorporeal CPR. Patients were grouped based on PaO2 after 24 hours of ECMO: normoxia (PaO2 60–150 mmHg), mild hyperoxia (PaO2 151–300 mmHg), and severe hyperoxia (PaO2 >300 mmHg). In-hospital mortality was evaluated using multivariable logistic regression. Results: Among 9959 patients, 3005 (30.2%) patients had mild hyperoxia and 1972 (19.8%) had severe hyperoxia. In-hospital mortality increased across groups: normoxia, 47.8%; mild hyperoxia, 55.6% (adjusted odds ratio, 1.37 [95% CI, 1.23–1.53]; P <0.001); severe hyperoxia, 65.4% (adjusted odds ratio, 2.20 [95% CI, 1.92–2.52]; P <0.001). A higher PaO2 was incrementally associated with increased in-hospital mortality (adjusted odds ratio, 1.14 per 50 mmHg higher [95% CI, 1.12–1.16]; P <0.001). Patients with a higher PaO2 had increased in-hospital mortality in each subgroup and when stratified by ventilator settings, airway pressures, acid-base status, and other clinical variables. In the random forest model, PaO2 was the second strongest predictor of in-hospital mortality, after older age. Conclusions: Exposure to hyperoxia during venoarterial ECMO support for cardiogenic shock is strongly associated with increased in-hospital mortality, independent from hemodynamic and ventilatory status. Until clinical trial data are available, we suggest targeting a normal PaO2 and avoiding hyperoxia in CS patients receiving venoarterial ECMO.
Cardiogenic shock severity and mortality in patients receiving venoarterial extracorporeal membrane oxygenator support
Abstract Aims Shock severity predicts mortality in patients with cardiogenic shock (CS). We evaluated the association between pre-cannulation Society for Cardiovascular Angiography and Intervention (SCAI) shock classification and mortality among patients receiving venoarterial (VA) extracorporeal membrane oxygenation (ECMO) support for CS. Methods and results We included Extracorporeal Life Support Organization (ELSO) Registry patients from 2010 to 2020 who received VA ECMO for CS. SCAI shock stage was assigned based on hemodynamic support requirements prior to ECMO initiation. In-hospital mortality was analyzed using multivariable logistic regression. We included 12 106 unique VA ECMO patient runs with a median age of 57.9 (interquartile range: 46.8, 66.1) years and 31.8% were females; 3472 (28.7%) were post-cardiotomy. The distribution of SCAI shock stages at ECMO initiation was: B, 821 (6.8%); C, 7518 (62.1%); D, 2973 (24.6%); and E, 794 (6.6%). During the index hospitalization, 6681 (55.2%) patients died. In-hospital mortality increased incrementally with SCAI shock stage (adjusted OR: 1.24 per SCAI shock stage, 95% CI: 1.17–1.32, P < 0.001): B, 47.5%; C, 52.8%; D, 60.8%; E, 65.1%. A higher SCAI shock stage was associated with increased in-hospital mortality in key subgroups, although the SCAI shock classification was only predictive of mortality in non-surgical (medical) CS and not in post-cardiotomy CS. Conclusion The severity of shock prior to cannulation is a strong predictor of in-hospital mortality in patients receiving VA ECMO for CS. Using the pre-cannulation SCAI shock classification as a risk stratification tool can help clinicians refine prognostication for ECMO recipients and guide future investigations to improve outcomes.
Cannulation strategies for acute type A dissection—role of central cannulation
Abstract OBJECTIVES The purpose of this study was to assess the safety and efficacy of direct cannulation of the ascending aorta in comparison with cannulating peripheral arteries. METHODS We retrospectively analysed type A dissection patients [n = 107; median (interquartile range [IQR]) age, 64 [53–73] years] from January 2008 to March 2018. The cohort was divided into 2 groups: direct ascending aorta cannulation (group A, n = 47; median [IQR] age, 69 [54–74] years; 34% female) and non-aortic cannulation (group B, n = 60; median [IQR] age, 62 [52–72] years; 20% female). Postoperative outcomes and long-term survival were compared. RESULTS Baseline characteristics were not significantly different between the 2 groups, except for higher creatinine in group B (median 0.9 vs 1.1, P = 0.028) and higher prevalence of dyslipidaemia in group A (58.7% vs 38.3%, P = 0.037). Overall early mortality was 12.1% (n = 13); 12.8% (n = 6) in group A and 11.7% (n = 7) in group B (P = 0.863). The incidence of stroke was 10.6% (n = 5) in group A and 6.7% (n = 4) in group B (P = 0.463). After adjusting for CPB and circulatory arrest times, there was no group difference in the length of ICU (P = 0.257) or hospital stay (P = 0.118), all-cause reoperation (P = 0.709), peak postoperative creatinine (P = 0.426) and lactate values (n = 60; P = 0.862). Overall survival at 1, 3 and 5 years was 84%, 78% and 73%, respectively, with no difference between the 2 groups after adjustment (P = 0.629). CONCLUSIONS Direct cannulation of the ascending aorta is a safe cannulation strategy for type A dissection repair, offering the opportunity for rapid arterial cannulation and antegrade perfusion.
Barrier Enclosure for Endotracheal Intubation in a Simulated COVID-19 Scenario: A Crossover Study
Utilization of venoarterial extracorporeal membrane oxygenation (VA-ECMO) is expanding, but dual VA-ECMO circuits to treat cardiogenic shock with refractory hypoxemia is unreported. We describe the case of combined cardiogenic and distributive shock due to necrotizing pulmonary blastomycosis. After initial central VA-ECMO cannulation, acute respiratory distress syndrome (ARDS) with increasing shunt resulted in significant central hypoxemia due to progressive ventilation-perfusion mismatch. An additional circuit provided complete oxygenation of the high circulating volume. After 4 months on support, he underwent successful heart-lung-kidney transplantation. Dual ECMO circuits are technically feasible and may be advantageous in specific circumstances of high pulmonary shunting resulting in excessive hypoxemia unbalanced with appropriate oxygen delivery.
The Perioperative Management of Ascending Aortic Dissection
Acute aortic syndromes are a distinct group of pathologies involving the wall of the aorta that present acutely and can be potentially fatal unless treated in a timely fashion. The syndrome is dominated by aortic dissections, which comprise ≥95% of all such presentations. Those involving the ascending aorta are particularly lethal and require specific and early surgical treatment compared to dissections involving other parts of the aorta. The surgical repair of an ascending aortic dissection presents multiple challenges to the anesthesiologist. Thoughtful management throughout the perioperative period is critical for minimizing the significant morbidity and mortality associated with this condition. In this narrative review, we provide an overview of the perioperative management of patients presenting for the surgical repair of an ascending aortic dissection. Preoperative discussion focuses on assessment, hemodynamic management, and risk stratification. The intraoperative section includes an overview of anesthetic management, transesophageal echocardiographic assessment, and coagulopathy, as well as surgical considerations that may influence anesthetic management.