Renal-Resistive Index and Acute Kidney Injury in Aortic Surgery: An Observational Pilot Study.

OBJECTIVE: Acute kidney injury (AKI) is a common perioperative complication in patients undergoing cardiovascular surgery, increasing mortality, morbidities, and costs. Recently, growing interest has risen in the use of the renal-resistive index (RRI) as a predictor of perioperative AKI. The aim of this study was to evaluate the role of RRI variation to identify postoperative AKI. DESIGN: An observational, prospective, pilot study. SETTING: Department of Vascular Surgery, University Hospital of Padova. PARTICIPANTS: The study authors included 53 consecutive patients undergoing aortic surgery from September 2018 to June 2019. MEASUREMENTS AND MAIN RESULTS: Basal and daily postoperative serum creatinine and urine output were assessed. RRI was measured preoperatively and on the first postoperative day. AKI was defined using Kidney Disease Improving Global Outcome criteria. Twelve patients out of 53 developed AKI. The RRI percentage increase (%RRI) was associated with the development of AKI by univariate regression (p = 0.01). The receiver operating characteristic curve showed an overall diagnostic accuracy of 0.75 (95% confidence interval [CI], 58.2-92.6). The cutoff of 7 percentage points in the %RRI resulted in early identification of AKI onset with 90% specificity (95% CI, 76.9-97.3). The net benefit of postoperative RRI-based management was 11%. CONCLUSIONS: RRI variation could be a useful tool to investigate kidney function in patients undergoing aortic surgery. The %RRI in the perioperative time seems to detect AKI onset early and potentially could enhance renal-protective management within 24 hours after surgery.

Two Consecutive Runs of Veno-Venous Extracorporeal Membrane Oxygenation in a Peripartum Patient with COVID-19 Acute Respiratory Distress Syndrome.

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) may be required to treat critically ill patients with COVID-19-associated severe acute respiratory distress syndrome (ARDS). We report the case of a 43-year-old peripartum patient, who underwent two sequential V-V ECMO runs. The first extracorporeal support was established for COVID-19 ARDS, as characterized by severe hypoxemia and hypercapnia (arterial partial pressure of oxygen to inspired oxygen fraction ratio 85 mmHg and arterial partial pressure of carbon dioxide 95 mmHg) and reduction of respiratory system static compliance to 25 mL/cmH2O, unresponsive to mechanical ventilation and prone positioning. After 22 days of lung rest, V-V ECMO was successfully removed and ventilator weaning initiated. A second V-V ECMO was required 7 days later, because of newly onset ARDS due to Pseudomonas aeruginosa ventilator-associated pneumonia. The second V-V ECMO run lasted 12 days. During both V-V ECMO runs, anticoagulation and ventilator settings were titrated through bedside thromboelastometry and electrical impedance tomography, respectively, without major complications. The patient was successfully decannulated, weaned from mechanical ventilation, and finally discharged home without oxygen therapy. At one-month follow-up, she showed good general conditions and no sign of respiratory failure.

Pulse contour analysis of arterial waveform in a high fidelity human patient simulator.

The measurement of cardiac output (CO) may be useful to improve the assessment of hemodynamics during simulated scenarios. The purpose of this study was to evaluate the feasibility of introducing an uncalibrated pulse contour device (MostCare, Vytech, Vygon, Padova, Italy) into the simulation environment. MostCare device was plugged to a clinical monitor and connected to the METI human patient simulator (HPS) to obtain a continuous arterial waveform analysis and CO calculation. In six different simulated clinical scenarios (baseline, ventricular failure, vasoplegic shock, hypertensive crisis, hypovolemic shock and aortic stenosis), the HPS-CO and the MostCare-CO were simultaneously recorded. The level of concordance between the two methods was assessed by the Bland and Altman analysis. 150-paired CO values were obtained. The HPS-CO values ranged from 2.3 to 6.6 L min-1 and the MostCare-CO values from 2.8 to 6.4 L min-1. The mean difference between HPS-CO and MostCare-CO was - 0.3 L min-1 and the limits of agreement were - 1.5 and 0.9 L min-1. The percentage of error was 23%. A good correlation between HPS-CO and MostCare-CO was observed in each scenario of the study (r = 0.88). Although MostCare-CO tended to underestimate the CO over the study period, good agreements were found between the two methods. Therefore, a pulse contour device can be integrated into the simulation environment, offering the opportunity to create new simulated clinical settings.