Abstract Introduction Cardiac arrest (CA) is the sudden cessation of cardiac activity, leading to haemodynamic collapse and high mortality. Advanced life support (ALS) standardises resuscitation, but the post-return of spontaneous circulation (ROSC) period remains turbulent and poorly understood. Up to 50% of patients who achieve ROSC struggle to maintain spontaneous circulation, leading to re-arrest, typically within minutes. Post-cardiac arrest syndrome (PCAS), involving brain injury and ischaemia-reperfusion injury, plays a key role in re-arrest. Pressure-volume loop (PVL) analysis offers insight into load-independent cardiac biomechanics in the post-ROSC period. The aim of this study is to explore the feasibility of PVL analysis in a swine model of CA. Methods This swine study utilised a ventricular fibrillation (VF) cardiac arrest model in combination with PVL analysis. The experiment included four phases: animal preparation, VF induction, resuscitation, and post-ROSC care. Yorkshire swine (45-70 kg) were sedated, anaesthetised, and VF was induced via an endocavitary electrode attached to a battery. After that, the animals were divided into 3-minute and 6-minute arrest groups before commencing ALS. Standard ALS protocols were followed, including CPR, defibrillation, and drug administration. If ROSC was obtained, animals underwent a 3-hour critical care period. Cardiac indices were compared between baseline and end-of-study values. Results Eight adult Yorkshire swine were enrolled in the study, with a mean weight of 50.2 ± 2.9 kg. VF induction was successfully achieved, and PVL data were collected in all animals except one, establishing a successful porcine VF CA model. In the resuscitation phase, all animals in the 3-minute group achieved ROSC, as opposed to one in the 6-minute group. Post-ROSC metabolic changes included acidaemia, elevated lactate and potassium, partially resolving by study end. Right ventricle PVL data were unreliable, while left ventricle PVL was reliable in 3 of 5 ROSC animals. Preload-recruitable stroke work (PRSW) data were found to be more reliable than the End-Diastolic Pressure-Volume Relationship (ESPVR), with a significant increase in LV PRSW of 34 ± 12% observed post-ROSC in all surviving animals (p<0.001). Discussion This study demonstrates the feasibility of applying PVL analysis to a post-ROSC swine model of cardiac arrest (CA). As expected, warm ischaemic time predicted ROSC, but PVL analysis offered valuable insights into load-independent parameters. While data quality issues hindered ESPVR analysis, PRSW was successfully evaluated, revealing a significant increase post-ROSC, highlighting its potential to guide the development of future therapeutic targets for post-ROSC interventions. The small sample size and technical challenges limited the scope of conclusions, emphasising the need for larger studies.Kaplan-Meier Curve and cycles to ROSC (A) LV PVL, (B) PRSW Pre and Post-ROSC
Time Is of the Essence: Impact of Transfer on Outcomes in Acute Mesenteric Ischemia
BACKGROUND: Acute mesenteric ischemia (AMI) is a vascular emergency where delays in diagnosis or treatment can lead to irreversible bowel injury and death. Many patients initially present to hospitals without surgical or vascular capabilities and require interhospital transfer. The clinical impact of such transfers on treatment and outcomes in AMI remains poorly defined. STUDY DESIGN: We performed a retrospective cohort study using the National Inpatient Sample (2019 to 2021) to evaluate the association between interhospital transfer and outcomes in patients with AMI. Adult patients with a primary diagnosis of AMI were identified using ICD-10 codes. Patients were categorized by transfer status. Multivariable logistic regression was used to evaluate associations with in-hospital mortality and procedural interventions, adjusting for age and comorbidity burden. RESULTS: Of 39,690 hospitalizations for AMI, 14.6% involved interhospital transfer. Transferred patients had a higher comorbidity burden and were more often treated at rural or micropolitan hospitals. They were significantly more likely to undergo major surgical and vascular procedures, including bowel resection (odds ratio [OR] 3.48), mesenteric bypass (OR 3.32), and angioplasty (OR 2.66; all p < 0.0001). Markers of critical illness, such as intubation (OR 2.15) and dialysis (OR 1.30), were also more frequent in this group. In-hospital mortality was significantly higher among transferred patients (OR 2.05), and transfer remained independently associated with increased mortality after adjusting for age and comorbidity burden (adjusted OR 1.67, 95% CI 1.32 to 2.10). CONCLUSIONS: Interhospital transfer in AMI is strongly associated with increased clinical severity and in-hospital mortality. These findings emphasize the urgency of early diagnosis, rapid triage, and timely access to definitive care, supporting the need for structured regional systems and transfer protocols for AMI.
A proposed clinical guide to delivering Lower Extremity Extracorporeal Distal Revascularization (LEEDR) as a bridge to definitive care in acute limb ischemia
Introduction Lower Extremity Extracorporeal Distal Revascularization (LEEDR) is a novel, preclinically tested technique designed to provide temporary limb perfusion in cases of acute limb ischemia when immediate revascularization is not feasible. Methods LEEDR employs an extracorporeal pump and circuit to draw arterial blood from a proximal inflow site and deliver it to an outflow artery within the ischemic limb. The system is designed for bedside initiation using percutaneous access. Results ALI from embolism, thrombosis, or trauma rapidly leads to irreversible tissue damage. Delays in revascularization are associated with high rates of limb loss and systemic complications. LEEDR offers a time-sensitive intervention aimed at mitigating these risks and preserving limb viability until definitive treatment is available. Conclusion LEEDR is a promising temporary perfusion strategy for limb salvage in ALI. This manuscript outlines its procedural components, technical considerations, and anticipated role in bridging patients to definitive revascularization.