Designing a new scoring system (QualyP Score) correlating the management of cardiopulmonary bypass to postoperative outcomes.

AIM: The aim of this study was to ascertain if a score, directly derived from CPB records, could correlate to major postoperative outcomes. METHODS: An additive score (QualyP Score) was created from 10 parameters: peak lactate value during CPB, peak VCO(2)i, lowest DO(2)i/VCO(2)i, peak respiratory quotient, CPB time, cross-clamp time, lowest CPB temperature, circulatory arrest, ultrafiltration during CPB, number of packed red cells transfused intraoperatively. The PerfSCORE was calculated, as well. Multivariable logistic regression models were built to detect the independent predictors of: peak lactate >3 mmol/L during the first three postoperative days; the incidence of acute kidney injury network (AKIN) 1-2-3; respiratory insufficiency; mortality. RESULTS: The mean score was 4.8±2.6 (0-10). A QualyP Score ≥1 was predictive of postoperative acidosis (OR=1.595). A score ≥2 was predictive of AKIN 2 (OR=1.268) and respiratory insufficiency (OR=1.526). A score ≥5 was predictive of AKIN 3 (OR=1.848) and mortality (OR=1.497). CONCLUSIONS: QualyP Score may help to provide a quality marker of perfusion, emphasizing the need for goal-directed perfusion strategies.

Structural analysis of the active site of porcine pancreatic elastase based on the X-ray crystal structures of complexes with trifluoroacetyl-dipeptide-anilide inhibitors.

The X-ray crystal structures of two new (trifluoroacetyl)dipeptide p-(trifluoromethyl)anilide (TFA-dipeptide-TFM) inhibitors complexed to porcine pancreatic elastase are presented. TFA-Val-Ala-TFM and TFA-Phe-Ala-TFM both bind to elastase with the TFA group in the S1 subsite, Val or Phe in the S2 subsite, Ala in the S3 subsite, and the TFM group in the S4 subsite. Five other TFA-dipeptide-anilide/elastase crystal structures are available (two TFA-X-Ala-p-(trifluoromethyl)anilide, X = Lys, Leu, and three TFA-Lys-X-p-isopropylanilide, X = Pro, Leu, Phe). The four inhibitors with the trifluoromethyl substituent on the anilide ring bind in a single mode to elastase, whereas superposition of the three inhibitors with the isopropyl substituent on the anilide ring show three different modes of binding to the protein [Mattos, C., et al. (1994) Nature Struct. Biol. 1, 55-58]. The seven structures are taken together in a detailed analysis of the active site of porcine pancreatic elastase. The inhibition constants for the inhibitors are used in combination with the crystal structures to understand the specificity of the different elastase subsites.