Prehospital invasive arterial blood pressure monitoring in critically ill patients attended by a UK helicopter emergency medical service- a retrospective observational review of practice.

BACKGROUND: Accurate haemodynamic monitoring in the prehospital setting is essential. Non-invasive blood pressure measurement is susceptible to vibration and motion artefact, especially at extremes of hypotension and hypertension: invasive arterial blood pressure (IABP) monitoring is a potential solution. This study describes the largest series to date of cases of IABP monitoring being initiated prehospital. METHODS: This retrospective observational study was conducted at East Anglian Air Ambulance (EAAA), a UK helicopter emergency medical service (HEMS). It included all patients attended by EAAA who underwent arterial catheterisation and initiation of IABP monitoring between 1st February 2015 and 20th April 2023. The following data were retrieved for all patients: sex; age; aetiology (medical cardiac arrest, other medical emergency, trauma); site of arterial cannulation; operator role (doctor/paramedic); time of insertion and, where applicable, times of pre-hospital emergency anaesthesia, and return of spontaneous circulation following cardiac arrest. Descriptive analyses were performed to characterise the sample. RESULTS: 13,556 patients were attended: IABP monitoring was initiated in 1083 (8.0%) cases, with a median age 59 years, of which 70.8% were male. 546 cases were of medical cardiac arrest: in 22.4% of these IABP monitoring was initiated during cardiopulmonary resuscitation. 322 were trauma cases, and the remaining 215 were medical emergencies. The patients were critically unwell: 981 required intubation, of which 789 underwent prehospital emergency anaesthesia; 609 received vasoactive medication. In 424 cases IABP monitoring was instituted en route to hospital. CONCLUSION: This study describes over 1000 cases of prehospital arterial catheterisation and IABP monitoring in a UK HEMS system and has demonstrated feasibility at scale. The high-fidelity of invasive arterial blood pressure monitoring with the additional benefit of arterial blood gas analysis presents an attractive translation of in-hospital critical care to the prehospital setting.

Lung ultrasound in ruling out COVID-19 pneumonia in the ED: a multicentre prospective sensitivity study.

PURPOSE: Early diagnosis of COVID-19 has a crucial role in confining the spread among the population. Lung ultrasound (LUS) was included in the diagnostic pathway for its high sensitivity, low costs, non-invasiveness and safety. We aimed to test the sensitivity of LUS to rule out COVID-19 pneumonia (COVIDp) in a population of patients with suggestive symptoms. METHODS: Multicentre prospective observational study in three EDs in Northeastern Italy during the first COVID-19 outbreak. A convenience sample of 235 patients admitted to the ED for symptoms suggestive COVIDp (fever, cough or shortness of breath) from 17 March 2020 to 26 April 2020 was enrolled. All patients underwent a sequential assessment involving: clinical examination, LUS, CXR and arterial blood gas. The index test under investigation was a standardised protocol of LUS compared with a pragmatic composite reference standard constituted by: clinical gestalt, real-time PCR test, radiological and blood gas results. Of the 235 enrolled patients, 90 were diagnosed with COVIDp according to the reference standard. RESULTS: Among the patients with suspected COVIDp, the prevalence of SARS-CoV-2 was 38.3%. The sensitivity of LUS for diagnosing COVIDp was 85.6% (95% CI 76.6% to 92.1%); the specificity was 91.7% (95% CI 86.0% to 95.7%). The positive predictive value and the negative predictive value were 86.5% (95%CI 78.8% to 91.7%) and 91.1% (95% CI 86.1% to 94.4%) respectively. The diagnostic accuracy of LUS for COVIDp was 89.4% (95% CI 84.7% to 93.0%). The positive likelihood ratio was 10.3 (95% CI 6.0 to 17.9), and the negative likelihood ratio was 0.16 (95% CI 0.1 to 0.3). CONCLUSION: In a population with high SARS-CoV-2 prevalence, LUS has a high sensitivity (and negative predictive value) enough to rule out COVIDp in patients with suggestive symptoms. The role of LUS in diagnosing patients with COVIDp is perhaps even more promising. Nevertheless, further research with adequately powered studies is needed. TRIAL REGISTRATION NUMBER: NCT04370275.

Combinatorial Peptide Ligand Library and two dimensional electrophoresis: new frontiers in the study of peritoneal dialysis effluent in pediatric patients.

Peritoneal dialysis effluent (PDE) is a fluid resulting from the close contact of peritoneal dialysis (PD) solutions with the peritoneal membrane (PM) and represents a readily available material for the search of biomarkers of PM function or damage. Our laboratory has developed a method for the in-depth proteomic characterization of PDE, which involves Combinatorial Peptides Ligand Library (CPLL) to reduce the dynamic range of protein concentration in PDE, followed by two-dimensional electrophoresis (2-DE). In this study we applied this method to the analysis of PDE proteome obtained from 19 pediatric patients on automated peritoneal dialysis (APD) with glucose-based PD solutions. The combined use of this proteomic approach highlighted a mean of 700 new proteins. Differences in PDE proteome profile were observed in relation with the duration of APD treatment. In particular, in patients on long-term APD, we observed an increase of intelectin-1, and a decrease of gelsolin. These changes were also observed by in vitro treatment of mesothelial cells with oxidative or pro-fibrotic stimulus which supported the biological role of these proteins' changes. In order to clarify the biological meaning of the observed differences, further step of our study will consist of the longitudinal evaluation of PDE proteome. BIOLOGICAL SIGNIFICANCE: The in-depth proteomic characterization of peritoneal dialysis effluent (PDE) in pediatric patients by the combined use of Combinatorial Peptide Ligand Library (CPLL) and two dimensional electrophoresis allowed to detect 1788 spots, a relevant part (724) of which were previously undetected in sample untreated with CPLL. In patients on long-term automated peritoneal dialysis, this proteomic approach allowed to identify 29 potential biomarkers that could be of help to identify patients with subclinical inflammation and/or developing peritoneal membrane fibrosis, thus adapting dialysis treatment accordingly.