Safety and efficacy of del Nido cardioplegia in adult cardiac surgery: experience in NICVD

Background: Cardioplegia is used to induce and provide a depolarized diastolic cardiac arrest to provide a motionless surgical field. Del Nido cardioplegia solution has been used extensively in congenital heart surgery for more than 20 years and more recently for adults. This observational study was performed to assess the safety and efficacy of del Nido cardioplegia in adult cardiac surgery patients. Methods: Total 140 adult patients selected for cardiac surgical procedure i.e., coronary artery bypass grafting (CABG), valve surgery, or CABG with valve surgery no need requiring cardiopulmonary bypass (CPB) were purposively allocated into two groups: a) del Nido cardioplegia (n=70) and b) blood cardioplegia (n=70). Primary outcomes assessed myocardial preservation. Results: The study compared del Nido (A) and blood cardioplegia (B) groups. Mean ages were 49.5±7.86 and 48.9±6.79 years, respectively (p=0.5641). BMI (26.98±2.3 vs 27.2±2.14 kg/m2, p=0.4846) and comorbid factors, including smoking (48% versus 51%) were similar. Differences were lower hemoglobin in A (males: 11.7±1.18 versus 13.6±0.55; females: 10.2±0.58 versus 12.2±0.21, p<0.0001) and CPB/ACC times for isolated CABG (A: 112.40±15.75/78.45±11.65 versus B: 123.8±18.55/86.28±15.26 minutes, p=0.0001). Post-operatively, more blood loss occurred in A, but they had shorter mechanical ventilation, ICU stay, and hospital stay durations. Other variables, like 30-day mortality, were similar. Conclusions: Evidence from this study suggests del Nido cardioplegia use in routine adult cases may be safe, result in comparable clinical outcomes, and streamline surgical workflow. The trend for troponin should be investigated further because it may suggest superior myocardial protection with the del Nido solution

Pore structural evolution of shale following thermochemical treatment

Shales experience heat treatment concurrent with the presence of water or steam during reservoir engineering interventions, such as high pressure water fracking and in-situ combustion of hydrocarbons. This work utilises a novel technique, which is a combination of gas sorption overcondensation and integrated mercury porosimetry experiments, not used before for any type of porous material, to study the pore structure of a shale rock, and its evolution following thermal treatment in the presence of water. Overcondensation allows the extension of gas sorption beyond the limits of conventional experiments to enable direct study of macroporosity. Scanning curve experiments, initiated from the complete boundary desorption isotherm, that can only be obtained for macropores by overcondensation experiments, has revealed details of the relative pore size spatial disposition within the network. In particular, it has been found that the new large voids formed by treatment are shielded by relatively much narrower pore windows. Use of a range of different adsorbates, with differing polarity, has allowed the chemical nature of the pore surface before and after treatment to be probed. Integrated rate of gas sorption and mercury porosimetry experiments have determined the level of the particular contribution to mass transport rates of the newly introduced porosity generated by thermal treatment. Combined CXT and mercury porosimetry have allowed the mapping of the macroscopic spatial distribution of even the new mesoporosity, and revealed the degree of pervasiveness of the new voids that leads to a thousand-fold increase in mass transport on thermal treatment