Predictive role of regional thigh tissue oxygen saturation monitoring during cardiopulmonary bypass in lung injury after cardiac surgery.

Acute respiratory distress syndrome (ARDS) is a serious complication following cardiac surgery mainly associated with the use of cardiopulmonary bypass (CPB), which could increase the risk of mortality and morbidity. This study investigated the association of regional oxygen saturation (rSO2) during CPB with postoperative outcomes, including respiratory function. Patients who underwent cardiac surgery with CPB from 2015 to 2019 were included. Near-infrared spectroscopy was used to monitor rSO2 at the forehead, abdomen, and thighs throughout the surgery. Postoperative markers associated with CPB were assessed for correlations with PaO2/FiO2 (P/F) ratios at intensive care unit (ICU) admission. Postoperative lung injury (LI) was defined as moderate or severe ARDS based on the Berlin criteria, and its incidence was 29.9% (20/67). On multiple regression analysis, the following were associated with P/F ratios at ICU admission: vasoactive-inotropic scores at CPB induction (P = 0.03), thigh rSO2 values during CPB (P = 0.04), and body surface area (P < 0.001). A thigh rSO2 of 71% during CPB was significantly predictive of postoperative LI with an area under the curve of 0.71 (P = 0.03), sensitivity of 0.70, and specificity of 0.68. Patients with postoperative LI had longer ventilation time and ICU stays. Thigh rSO2 values during CPB were a potential predictor of postoperative pulmonary outcomes.

Monitoring of intraoperative femoral oxygenation predicts acute kidney injury after pediatric cardiac surgery.

Cardiopulmonary bypass-associated acute kidney injury (CPB-AKI) is a pediatric cardiac surgery postoperative complication that is associated with a longer duration of mechanical ventilation and length of hospital stay. Identifying an early predictor of CPB-AKI is critical. Near infrared spectroscopy (NIRS), which can provide real-time monitoring of regional tissue oxygen saturation (rSO2) during CPB, may predict CPB-AKI in an early phase of surgical treatment. This study analyzed clinical data from 87 children who underwent an elective surgical repair of ventricular septal defect (VSD) from January 2013 to March 2019. NIRS sensors were placed on the patients' forehead, abdomen, and thighs. The pediatric modified risk, injury, failure, loss, and end-stage (p-RIFLE) score was determined for each patient postoperatively. The incidence of AKI based on the p-RIFLE classification was 11.5% at the end of surgery, 23.0% at 24 h after surgery, and 5.7% at 48 h after surgery. The AKI incidence rate was highest at 24 h after surgery. Multiple regression analysis revealed that femoral oxygenation (rSO2) during CPB, CPB time, oxygen delivery index (DO2i), and lactate at the end of CPB were independent risk factors for AKI. Receiver-operating characteristic curve analysis indicated that femoral oxygenation of 74% or less predicted AKI development within 24 h after surgery. In conclusion, rSO2 measured at the thigh during CPB is highly predictive of CPB-AKI.

Continuous hemofiltration model using porcine blood for comparing filter life.

The purpose of the present study was to establish a continuous hemofiltration model using porcine blood to compare filter life. Continuous hemofiltration (CHF) experiments were performed using an in vitro hemofilter evaluation system utilizing porcine blood containing trisodium citrate in addition to nafamostat mesilate as anticoagulants. The lifetime of the hemofilter was evaluated using the transmembrane pressure and the pressure drop across the hemofilter at varying trisodium citrate concentrations. The porcine blood used in this experiment was considered to be in a slightly hypercoagulable state because of the continuous contact with non-biological materials and calcium inflow from substitution fluid. Blood containing 7 or 8 mM of trisodium citrate and nafamostat mesilate could be effectively used to compare the lifetimes of hemofilters utilized under the same conditions. In this CHF model using porcine blood, the plugging of the hollow fibers occurred shortly after the plugging of the membrane pores. In conclusion, a CHF model using porcine blood can be established by adjusting the concentration of trisodium citrate added to the blood.