Cardiac output monitoring during abdominal aortic cross clamping: a comparison between Vigileo/FloTrac system and transoesophageal Doppler

Cardiac output (CO) monitoring is one of the key points in the hemodynamic evaluation of critically ill patients, and can be useful in various settings of high-risk surgery. There is a lack of evidence that the extensive use of invasive devices in the hemodynamic monitoring has a good impact in terms of outcome [1], and less invasive systems have been proposed. Our aim was to compare the CO estimated by Vigileo/FloTrac with the blood flow in thoracic aorta as measured by transoesophageal Doppler in patients undergoing open abdominal aortic aneurysm repair, during the aortic cross-clamping (AoX) phase. We have measured the Augmentation Index (AI), a parameter related to vascular stiffness, using the applanation tonometry method, in order to have a better understanding of the effect of AoX on blood pressure waves. Methods We enrolled 10 consecutive patients (10 men; age 66 \ub1 6 years) undergoing elective open AAA repair (ASA II to III) under general anesthesia. Radial arterial access was used for semi-invasive determination of blood pressures and CO (APCO) with the Vigileo. An esophageal Doppler was positioned after clinical stabilization. Applanation tonometry was measured just before and after the aortic clamping. Results We found a significant (P < 0.05) increase in CO reported by Vigileo/FloTrac system in the post-clamping phase, when compared with the pre-clamping and basal phases, while the blood flow in thoracic aorta resulted decreased, according with the theory of redistribution of fluids in the splanchnic venous vasculature [2]. There was an important contribution of the wave reflection to the aortic pulse pressure wave after the AoX, as expressed by a significant increase in the AI. Conclusions The Vigileo/FloTrac system appears to overestimate CO after AoX when compared with the measure of blood flow in thoracic aorta, and this result could be influenced by the pulse pressure wave reflection occurring after clamping. In high-risk surgical settings, other situations of rapid change of systemic resistance vessels could be similarly misread, thus suggesting the necessity of a more tailored Vigileo algorithm

Vision and visual history in elite-/near-elite level cricketers and rugby-league players

Background: The importance of optimal and/or superior vision for participation in high-level sport remains the subject of considerable clinical research interest. Here we examine the vision and visual history of elite/near-elite cricketers and rugby-league players. Methods: Stereoacuity (TNO), colour vision, and distance (with/without pinhole) and near visual acuity (VA) were measured in two cricket squads (elite/international-level, female, n=16; near-elite, male, n=23) and one professional rugby-league squad (male, n=20). Refractive error was determined, and details of any correction worn and visual history were recorded. Results: Overall, 63% had their last eye-examination within 2 years. However, some had not had an eye examination for 5 years, or had never had one (near-elite-cricketers: 30%; rugby-league players: 15%; elite-cricketers: 6%). Comparing our results for all participants to published data for young, optimally-corrected, non-sporting adults, distance VA was ~1 line of letters worse than expected. Adopting α=0.01, the deficit in distance-VA deficit was significant, but only for elite-cricketers (p0.02 for all comparisons). On average, stereoacuity was better than in young adults, but only in elite-cricketers (p<0.001; p=0.03, near-elite-cricketers; p=0.47, rugby-league -players). On-field visual issues were present in 27% of participants, and mostly (in 75% of cases) comprised uncorrected ametropia. Some cricketers (near-elite: 17.4%; elite: 38%) wore refractive correction during play but no rugby-league player did. Some individuals with prescribed correction choose not to wear it when playing. Conclusion: Aside from near stereoacuity in elite-cricketers, these basic visual abilities were not better than equivalent, published data for optimally-corrected adults. 20-25% exhibited sub-optimal vision, suggesting that the clearest possible vision might not be critical for participation at the highest levels in the sports of cricket or rugby-league. Although vision could be improved in a sizeable proportion of our sample, the impact of correcting these, mostly subtle, refractive anomalies on playing performance is unknown

Efficacy of pulsatile flow perfusion in adult cardiac surgery: Hemodynamic energy and vascular reactivity

Background: The role of pulsatile (PP) versus non-pulsatile (NP) flow during a cardiopulmonary bypass (CPB) is still debated. This study’s aim was to analyze hemodynamic effects, endothelial reactivity and erythrocytes response during a CPB with PP or NP. Methods: Fifty-two patients undergoing an aortic valve replacement were prospectively randomized for surgery with either PP or NP flow. Pulsatility was evaluated in terms of energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE). Systemic (SVRi) and pulmonary (PVRi) vascular resistances, endothelial markers levels and erythrocyte nitric-oxide synthase (eNOS) activity were collected at different perioperative time-points. Results: In the PP group, the resultant EEP was 7.3% higher than the mean arterial pressure (MAP), which corresponded to 5150 ± 2291 ergs/cm3 of SHE. In the NP group, the EEP and MAP were equal; no SHE was produced. The PP group showed lower SVRi during clamp-time (p = 0.06) and lower PVRi after protamine administration and during first postoperative hours (p = 0.02). Lower SVRi required a higher dosage of norepinephrine in the PP group (p = 0.02). Erythrocyte eNOS activity results were higher in the PP patients (p = 0.04). Renal function was better preserved in the PP group (p = 0.001), whereas other perioperative variables were comparable between the groups. Conclusions: A PP flow during a CPB results in significantly lower SVRi, PVRi and increased eNOS production. The clinical impact of increased perioperative vasopressor requirements in the PP group deserves further evaluation

The effects of temperature management on brain microcirculation, oxygenation and metabolism

Purpose: Target temperature management (TTM) is often used in patients after cardiac arrest, but the effects of cooling on cerebral microcirculation, oxygenation and metabolism are poorly understood. We studied the time course of these variables in a healthy swine model.Methods: Fifteen invasively monitored, mechanically ventilated pigs were allocated to sham procedure (normothermia, NT; n = 5), cooling (hypothermia, HT, n = 5) or cooling with controlled oxygenation (HT-Oxy, n = 5). Cooling was induced by cold intravenous saline infusion, ice packs and nasal cooling to achieve a body temperature of 33–35 °C. After 6 h, animals were rewarmed to baseline temperature (within 5 h). The cerebral microvascular network was evaluated (at baseline and 2, 7 and 12 h thereafter) using sidestream dark-field (SDF) video-microscopy. Cerebral blood flow (laser Doppler MNP100XP, Oxyflow, Oxford Optronix, Oxford, UK), oxygenation (PbtO2, Licox catheter, Integra Lifesciences, USA) and lactate/pyruvate ratio (LPR) using brain microdialysis (CMA, Stockholm, Sweden) were measured hourly. Results: In HT animals, cerebral functional capillary density (FCD) and proportion of small-perfused vessels (PSPV) significantly decreased over time during the cooling phase; concomitantly, PbtO2 increased and LPR decreased. After rewarming, all microcirculatory variables returned to normal values, except LPR, which increased during the rewarming phase in the two groups subjected to HT when compared to the group maintained at normothermia. Conclusions: In healthy animals, TTM can be associated with alterations in cerebral microcirculation during cooling and altered metabolism at rewarming

Twenty-Minute No-Touch Period Before Controlled DCD Heart Retrieval: Is There Still a Chance for Successful Recovery? The Italian Experience

Purpose: Hearts from cDCD donors are becoming an increasing source for heart transplantation (HT). Unfortunately, their use has been questioned for years in Italy given the longest-in-the-world no-touch period after death declaration (20 min). We aimed to analyze the early Italian experience using cDCD hearts for transplantation. Methods: We prospectively collected and analyzed all clinical data of all patients who underwent cDCD HT since ethical approval of the program by the National Transplant Center (CNT) (April 2023), in 5 centers which were authorized to perform cDCD HT. Results: Since April 2023, 8 cDCD HT were performed (recipient M 100%, median recipient age 58 years, IQR 44-60). Two patients were hospitalized and under inotropes before HT, no patients were on mechanical support before HT. Donor hearts (M 100%, median age 37 years, IQR 23-51) did not present any coronary lesions. Median warm ischemic time (WIT), functional WIT and asystolic time were 53min (IQR 46-62), 42min (IQR 39-44) and 28min (IQR 26-29), respectively. All the cases were performed under TA-NRP (7 CPB, 1 ECMO) through femoral vessels cannulation. No ex vivo machine perfusion devices were used. Median TA-NRP duration was 106min (IQR 86-140). Median time within TA-NRP stop and donor cardiectomy was 56min (IQR 40-126). Median cold ischemic time was 93min (IQR 78-144). Two patients required ECMO; of these, 1 patient was switched to RVAD and was finally recovered. 30-day and in-hospital mortality occurred in only 1 patient. Among the 7 alive patients, only 1 patient presented acute cellular rejection≥2 after HT. All the alive patients showed preserved ejection fraction (≥55%) and preserved RV function, with only mild tricuspid regurgitation at discharge (Table 1). Conclusion: Our preliminary data show that cDCD heart transplantation is feasible and safe also with longer donor asystolic times. Additional follow-up data and a larger cohort of patients are required to confirm these promising results

Fatal cytokine release syndrome by an aberrant FLIP/STAT3 axis

Inflammatory responses rapidly detect pathogen invasion and mount a regulated reaction. However, dysregulated anti-pathogen immune responses can provoke life-threatening inflammatory pathologies collectively known as cytokine release syndrome (CRS), exemplified by key clinical phenotypes unearthed during the SARS-CoV-2 pandemic. The underlying pathophysiology of CRS remains elusive. We found that FLIP, a protein that controls caspase-8 death pathways, was highly expressed in myeloid cells of COVID-19 lungs. FLIP controlled CRS by fueling a STAT3-dependent inflammatory program. Indeed, constitutive expression of a viral FLIP homolog in myeloid cells triggered a STAT3-linked, progressive, and fatal inflammatory syndrome in mice, characterized by elevated cytokine output, lymphopenia, lung injury, and multiple organ dysfunctions that mimicked human CRS. As STAT3-targeting approaches relieved inflammation, immune disorders, and organ failures in these mice, targeted intervention towards this pathway could suppress the lethal CRS inflammatory state

Incidence of hospital-acquired infections due to carbapenem-resistant Enterobacterales and Pseudomonas aeruginosa in critically ill patients in Italy: a multicentre prospective cohort study

BackgroundCarbapenem-Resistant Gram-Negative Bacteria, including Carbapenem-Resistant Enterobacterales (CRE) and Carbapenem-Resistant Pseudomonas aeruginosa (CRPA), are common causes of infections in intensive care units (ICUs) in Italy.ObjectiveThis prospective observational study evaluated the epidemiology, management, microbiological characterization, and outcomes of hospital-acquired CRE or CRPA infections treated in selected ICUs in Italy.MethodsThe study included patients with hospital-acquired infections due to CRE and CRPA treated in 20 ICUs from June 2021 to February 2023. The primary endpoint was the 1-year incidence of CRE/CRPA infections. Secondary endpoints included the rate of CRE/CRPA infections, mortality in ICU, infection outcome, and microbiological characterization.ResultsAmong 13,088 patients admitted over the 12-month study period across each of the 20 ICUs, 283 had CRE infections, and 138 had CRPA infections. The incidence of CRE and CRPA infections was 3.57 per 1000 patient days and 1.74 per 1000 patient days, respectively. The proportion of CRE and CRPA infections over the total number of infections due to Enterobacterales and Pseudomonas aeruginosa was 19.2% and 26.8%, respectively. Among 158 patients included in the full analysis, 98 (62%) had CRE infections and 60 (38%) had CRPA infections. Ventilator-associated pneumonia and bloodstream infections were the most common infections, occurring in 53.8 and 34.2% of cases. Empirical therapy targeting gram-negative pathogens resulted inappropriate in 59.2% of analysed patients (77/130). The overall crude mortality in ICU rate was 30.4%, with a higher rate in CRE patients (36.7%) than in CRPA patients (20.0%). Clinical success, including microbiological eradication, was achieved in 50.6% of cases. Klebsiella pneumoniae was observed as the predominant CRE species, and all CRE isolates, including metallo-beta-lactamases-producing CRE (MBL-CRE), were susceptible to Aztreonam-Avibactam.ConclusionsThese results highlight the high prevalence of CRE/CRPA infections in Italian ICUs and emphasize the need for enhanced prevention and surveillance strategies