The Effect of Lower Tidal Volume Ventilation Facilitated by Extracorporeal Carbon Dioxide Removal Compared With Conventional Lung Protective Ventilation on Cardiac Function.

OBJECTIVES: Lower tidal volume ventilation (targeting 3 mL/kg predicted body weight, PBW) facilitated by extracorporeal carbon dioxide removal (ECCO2R) has been investigated as a potential therapy for acute hypoxemic respiratory failure (AHRF) in the pRotective vEntilation with veno-venouS lung assisT in respiratory failure (REST) trial. We investigated the effect of this strategy on cardiac function, and in particular the right ventricle. DESIGN: Substudy of the REST trial. SETTING: Nine U.K. ICUs. PATIENTS: Patients with AHRF (Pao2/Fio2 < 150 mm Hg [20 kPa]). INTERVENTION: Transthoracic echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurements were collected at baseline and postrandomization in patients randomized to ECCO2R or usual care. MEASUREMENTS: The primary outcome measures were a difference in tricuspid annular plane systolic excursion (TAPSE) on postrandomization echocardiogram and difference in NT-proBNP postrandomization. RESULTS: There were 21 patients included in the echocardiography cohort (ECCO2R, n = 13; usual care, n = 8). Patient characteristics were similar in both groups at baseline. Median (interquartile range) tidal volumes were lower in the ECCO2R group compared with the usual care group postrandomization; 3.6 (3.1-4.2) mL/kg PBW versus 5.2 (4.9-5.7) mL/kg PBW, respectively (p = 0.01). There was no difference in the primary outcome measure of mean (sd) TAPSE in the ECCO2R and usual care groups postrandomization; 21.3 (5.4) mm versus 20.1 (3.2) mm, respectively (p = 0.60). There were 75 patients included in the NT-proBNP cohort (ECCO2R, n = 36; usual care, n = 39). Patient characteristics were similar in both groups at baseline. Median (interquartile range [IQR]) tidal volumes were lower in the ECCO2R group than the usual care group postrandomization; 3.8 (3.3-4.2) mL/kg PBW versus 6.7 (5.8-8.1) mL/kg PBW, respectively (p < 0.0001). There was no difference in median (IQR) NT-proBNP postrandomization; 1121 (241-5370) pg/mL versus 1393 (723-4332) pg/mL in the ECCO2R and usual care groups, respectively (p = 0.30). CONCLUSIONS: In patients with AHRF, a reduction in tidal volume facilitated by ECCO2R, did not modify cardiac function.

Pre-hospital and retrieval medicine in Scotland: a retrospective cohort study of the workload and outcomes of the emergency medical retrieval service in the first decade of national coverage.

BACKGROUND: The Emergency Medical Retrieval Service (EMRS) has provided national pre-hospital critical care and aeromedical retrieval in Scotland since 2010. This study investigates trends in the service and patients attended over the last decade; and factors associated with clinical deterioration and pre-hospital death. METHODS: A retrospective cohort study was conducted of all service taskings over ten years (2011-2020 inclusive). The EMRS electronic database provided data on location, sociodemographic factors, diagnoses, physiological measurements, clinical management, and pre-hospital deaths. Binary logistic regression models were used to determine change in physiology in pre-hospital care, and factors associated with pre-hospital death. Geospatial modelling, using road and air travel time models, was used to explore transfer times. RESULTS: EMRS received 8,069 taskings over the study period, of which 2,748 retrieval and 3,633 pre-hospital critical care missions resulted in patient contact. EMRS was more commonly dispatched to socioeconomically deprived areas for pre-hospital critical care incidents (Spearman's rank correlation, r(8)=-0.75, p = 0.01). In multivariate analysis, systolic blood pressure < 90mmHg, respiratory rate < 6/min or > 30/min, and Glasgow Coma Score ≤ 14 were associated with pre-hospital mortality independent of demographic factors. Geospatial modelling suggested that aeromedical retrieval reduced the mean time to a critical care unit by 1 h 46 min compared with road/ferry transportation. CONCLUSION: EMRS continues to develop, delivering Pre-Hospital and Retrieval Medicine across Scotland and may have a role in addressing health inequalities, including socioeconomic deprivation and geographic isolation. Age, specific distances from care, and abnormal physiology are associated with death in pre-hospital critical care.

Traumatic pseudoaneurysms of the superficial temporal artery.

Persistent scalp swelling following blunt head injury may be the presenting feature of a pseudoaneurysm of the temporal artery. This paper describes three patients who sustained injuries to the temporal region, which resulted in the formation of pseudoaneurysms. All patients had a delayed presentation to the Emergency Department. We describe their clinical presentations, subsequent management and pitfalls encountered when dealing with this condition.