Saunders, Hollie

Introduction Post-intubation hypotension (PIH) is a frequent complication of emergency endotracheal intubation and is associated with increased mortality. Early identification of high-risk patients remains challenging, and existing prediction tools demonstrate moderate accuracy. Objective We aim to identify predictors of PIH and develop machine learning models for pre-intubation risk stratification. Methods We conducted a multicentre retrospective study across 3 Mayo Clinic hospitals, including 600 adults undergoing urgent intubation in the intensive care unit. PIH was defined by mean arterial pressure<65 mm Hg, systolic blood pressure (SBP)<80 mm Hg or ≥40% decline or vasopressor initiation/escalation within 30 min. Three model frameworks were developed: Shock Indices (SIs), Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA), incorporating demographic, haemodynamic, laboratory and sedation variables. Various machine learning algorithms were applied to analyse the three models. Results PIH occurred in 46% of patients included in the study. In the SIs model, stepwise logistic regression achieved an area under the curve (AUC) of 0.76. The APACHE II framework showed the strongest performance, with random forest achieving an ROC AUC of 0.82 and the ensemble model demonstrating the highest overall discrimination (Receiver operator Curve [ROC] AUC 0.83) with favourable accuracy and F1 metrics. The SOFA framework showed moderate performance, with an ensemble ROC AUC of 0.73. Key predictors included pre-intubation vasopressor use, SBP, platelet count and haematological parameters. Conclusions Machine learning models using routinely available pre-intubation data showed potential to predict PIH in this retrospective proof-of-concept study. These findings support further development of anticipatory artificial intelligence-driven risk stratification in critical care, but the models should not be considered ready for bedside implementation until they undergo prospective validation in larger, independent and more diverse cohorts.

Abstract Rationale Transthoracic echocardiography (TTE) is a very useful measure of cardiac function in patients with pulmonary hypertension (PH), along with right heart catheterization, which is considered to be the gold standard of measurement. It is non-invasive, quick and a good screening tool to assess the function of a failing right ventricle against elevated pulmonary pressures. Portopulmonary hypertension (POPH) is defined as PH associated with portal hypertension. The Tricuspid Annular Plane Systolic Excursion to Systolic Pulmonary Artery Pressure (TAPSE/SPAP) ratio has been found to be an effective prognosticator in different subtypes of PH. This study focuses on the role of TAPSE/SPAP ratio in prognosis of patients with POPH undergoing liver transplantation. Methods This was a single-center retrospective study of POPH patients undergoing liver transplantation at Mayo Clinic Florida from June 2003 to December 2023. It included patients with POPH with a mean pulmonary pressure &gt;20 mm Hg undergoing liver transplantation. Patients with incomplete TTE data, coexisting renal failure on dialysis and requiring liver retransplant were excluded. This study included 27 patients. The last TTE report before liver transplantation was used for data analysis. The TAPSE/SPAP ratio was investigated as predictor of all-cause mortality following liver transplant using Cox regression and area under ROC curve. (Brackets contain 95% C.I.) Time to death after liver transplantation was considered. Patients were followed till August 1, 2024. (The correlation of this ratio-TAPSE/SPAP with some catheterization measured pulmonary pressures and indices have been included in Table 1.) Results Among 27 patients, 13 were female, 14 male. The most common causes of liver failure in these patients were non alcoholic fatty liver disease (NASH) and alcoholic liver disease. Rarely, some etiologies like sarcoidosis, autoimmune hepatitis, primary sclerosing cholangitis and hepatitis B/C were present. There were 7 deaths among total of 27 patients. The hazard ratio (HR) of TAPSE/SPAP for overall mortality by Cox regression was 0.01 (0.00-0.58), p = 0.03. The area under ROC curve was 0.76 (0.55-0.96), p = 0.01 [Also for TAPSE alone, the area under ROC curve was 0.74 (0.51-0.97), p = 0.05] Conclusion This study infers that TAPSE/SPAP ratio seems to be a good predictor of survival in POPH patients undergoing liver transplant, with a higher ratio associated with decreased all-cause mortality. It suggests that TAPSE alone might also be a good predictor with higher TAPSE associated with decreased mortality. This abstract is funded by: None

Abstract Rationale Pulmonary hypertension (PH) develops in up to 50% of patients with advanced interstitial lung disease (ILD) and is associated with increased morbidity, mortality, and impaired quality of life. Early recognition is essential, as available therapy for ILD-PH has been shown to improve outcomes. Identifying physiologic markers of PH may facilitate earlier referral for right heart catheterization (RHC) and initiation of targeted treatment. Thus, this study aimed to (1) compare functional parameters between ILD patients with and without RHC-confirmed PH, and (2) assess the applicability of previously proposed ILD-PH screening criteria. Methods We retrospectively analyzed ILD transplant candidates with available pre-transplant pulmonary function tests (FVC%, DLCO%), echocardiographic right-ventricular systolic pressure (RVSP), six-minute walk distance (6MWD) with oxygen requirement, and RHC data. PH was defined according to the 2022 ESC/ERS criteria. Functional parameters were compared between patients with and without PH. Among those without a prior PH diagnosis, screening thresholds derived from previously published tools were applied (RVSP ≥ 35 mmHg, DLCO &lt; 40%, FVC/DLCO &gt; 1.6, 6MWD &lt; 350 m, or oxygen use during 6MWD). Results Of 107 ILD patients evaluated, 90 had complete RHC data (48 ILD-PH, 42 ILD without PH). Group comparisons are summarized in Table 1. Patients with PH had lower DLCO% (median 18.5 [11.5-26.7] vs 26.5 [20.0-34.7], p = 0.08), higher FVC/DLCO ratios (2.68 [2.1-3.4] vs 1.7 [1.4-2.6], p = 0.08), and higher RVSP (55 [39.7-63.2] vs 39.5 [29-48] mmHg, p = 0.002). Oxygen requirement during 6MWD was more frequent in ILD-PH (79.2% vs 61.9%, p = 0.08). Among patients with PH, 38 (79.16%) had no formal diagnosis prior to pre-transplant RHC. Of these cases, all (100%) met ≥3 screening criteria, most commonly DLCO &lt; 40% (n = 38, 100%), FVC/DLCO &gt; 1.6 (n = 37, 97.3%), and 6MWD &lt; 350 m (n = 33, 86.8%). Additionally, 32 patients (84.21%) met ≥4 criteria and 8 (21.05%) met all five criteria. Conclusion In ILD transplant candidates, patients with PH had worse functional profiles when compared to those without PH, and nearly 80% of PH cases were previously undiagnosed. Systematic application of validated PH screening tools in ILD populations may facilitate earlier recognition, potentially improving patient outcomes. This abstract is funded by: None

Background/Objectives: Peri-intubation hypotension is a known complication of endotracheal intubation. In the hospital setting, peri-intubation hypotension has been shown to increase hospital mortality and length of stay. The use of prophylactic vasopressors at the time of sedation induction to prevent peri-intubation hypotension has been raised. This systematic review and meta-analysis aims to review the safety and efficacy of this practice. Methods: The study was fully registered with PROSPERO on 13 October 2022, and screening for eligibility was initiated on 20 September 2024. Randomized controlled trials, along with retrospective or prospective cohort studies, were included in the search. The terms “peri-intubation hypotension”, “vasopressors”, “intubation”, and “anesthesia induced hypotension” were used to search the title/summary in PubMed, Cochrane Library, and Google Scholar databases. An assessment of bias for each study was conducted using the Newcastle-Ottawa Quality Assessment Scale. The primary outcome was the rate of hypotension peri-intubation. Any complications secondary to hypotension or vasopressors were the secondary outcome. Results: We identified 13 studies, which were all randomized controlled studies, to include in the final analysis. The risk ratio for preventing peri-intubation hypotension was 1.6 (95% CI, 1.2–2.14) with the use of prophylactic phenylephrine while giving propofol versus no prophylactic vasopressors and 1.28 (95% CI 1.03–1.60) with the use of ephedrine. Conclusions: These findings suggest that in patients undergoing intubation in the operating room with propofol, prophylactic vasopressors given with induction for intubation decrease the odds of hypotension.

The evidence on indications, outcomes, and complications with the use of extracorporeal membrane oxygenation (ECMO) in the setting of interstitial lung disease (ILD) is limited in the existing literature. We performed a systematic review and meta-analysis for the use of ECMO in the setting of ILD to study the prognostic factors associated with in-hospital mortality. Eighteen unique studies with a total of 1,356 patients on ECMO for ILD were identified out of which 76.5% were on ECMO as a bridge to transplant (BTT) and the rest as a bridge to recovery (BTR). The overall in-hospital mortality was 45.76%, with 71.3% and 37.8% for BTR and BTT, respectively. Among the various prognostic factors, mortality was lower with younger age (mean difference = 3.15, 95% confidence interval [CI] = 0.82–5.49), use of awake veno-arterial (VA)-ECMO compared to veno-venous (VV)-ECMO (unadjusted odds ratio [OR] = 0.22, 95% CI = 0.13–0.37) in the overall cohort. In the setting of BTT, the use of VA-ECMO had a decreased hazard ratio (HR) compared to VV-ECMO (adjusted HR = 0.34, 95% CI = 0.15–0.81, p = 0.015). The findings of our meta-analysis are critical but are derived from retrospective studies with small sample sizes and thus are of low to very low-GRADE certainty.

Objective The aims of this study were to assess whether a relationship between anti–SSA-52 and interstitial lung disease (ILD) can be further defined, and to enhance screening, detection, and potentially guide treatment. Methods A historical cohort study of 201 patients was conducted at a single tertiary care center between January 1, 2016 and December 31, 2020. All included patients were anti–SSA-52 antibody positive. Chart review was performed for laboratory values, symptoms, pulmonary function tests, treatment, and imaging. Chest computed tomographies were reviewed by chest radiologists. Results Among anti–SSA-52 antibody–positive patients, ILD was found in 125 (62.2%) compared with 76 (37.8%) with no ILD (p = 0.001). For those with ILD, 78 (62.4%) were diagnosed with connective tissue disease (CTD)–associated ILD, 28 (22.4%) were diagnosed ILD only, and 19 (15.2%) met the criteria for interstitial pneumonia with autoimmune features. In patients with CTD-ILD, 18 (23.0%) had their ILD diagnosis made over 6 months before a CTD diagnosis, and an additional 43 (55.1%) had their ILD and CTD diagnosed within 6 months of each other (p < 0.001). Common computed tomography patterns were nonspecific interstitial pneumonia/organizing pneumonia overlap in 44 (35.2%), 25 (20.0%) nonspecific interstitial pneumonia, and 15 (12%) usual interstitial pneumonia. Twenty-eight (35.9%) had antisynthetase syndrome, followed by 16 (20.5%) with dermatomyositis, 10 (12.8%) with CTD overlap, and 6 (7.7%) with systemic scleroderma. Conclusions There was a significant association between anti–SSA-52 antibodies and ILD across a wide spectrum of rheumatological diagnoses. A significant portion of patients were diagnosed with ILD either at the same time or before their CTD diagnosis. Further study will be needed to assess effective treatment and response.