Postoperative pulmonary complications and mortality after major abdominal surgery. An observational multicenter prospective study.

BACKGROUND: Postoperative pulmonary complications (PPCs) significantly contribute to postoperative morbidity and mortality. We conducted a study to determine the incidence of PPCs after major elective abdominal surgery and their association with early and 1-year mortality in patient without pre-existing respiratory disease. METHODS: We conducted a multicenter observational prospective clinical study in 40 Italian centers. 1542 patients undergoing elective major abdominal surgery were recruited in a time period of 14 days and clinically managed according to local protocol. The primary outcome was to determine the incidence of PPCs. Further, we aimed to identify independent predictors for PPCs and examine the association between PPCs and mortality. RESULTS: PPCs occurred in 12.6% (95% CI 11.1-14.4%) of patients with significant differences among general (18.3%, 95% CI 15.7-21.0%), gynecological (3.7%, 95% CI 2.1-6.0%) and urological surgery (9.0%, 95% CI 6.0-12.8%). PPCs development was associated with known pre- and intraoperative risk factors. Patients who developed PPCs had longer length of hospital stay, higher risk of 30-days hospital readmission, and increased in-hospital and one-year mortality (OR 3.078, 95% CI 1.825-5.191; P<0.001). CONCLUSIONS: The incidence of PPCs in patients without pre-existing respiratory disease undergoing elective abdominal surgery is high and associated with worse clinical outcome at one year after surgery. General surgery is associated with higher incidence of PPCs and mortality compared to gynecological and urological surgery.

Regulative idealization: A Kantian approach to idealized models.

Scientific models typically contain idealizations, or assumptions that are known not to be true. Philosophers have long questioned the nature of idealizations: Are they heuristic tools that will be abandoned? Or rather fictional representations of reality? And how can we reconcile them with realism about knowledge of nature? Immanuel Kant developed an account of scientific investigation that can inspire a new approach to the contemporary debate. Kant argued that scientific investigation is possible only if guided by ideal assumptions-what he calls "regulative ideas". These ideas are not true of objects of nature, and yet they are not heuristic tools or fictional representations. They are necessary rules governing the construction and assessment of scientific explanations. In this paper, I suggest that some idealizations can be interpreted as having necessary regulative value and as being compatible with scientific realism. I first analyze the puzzle of the nature of idealization and present the main approaches to this topic in the literature. Second, I reconsider the puzzle vis-à-vis a restricted, Kantian definition of idealization and a novel characterization of the relation between idealization and truth. Finally, I discuss in detail an example of idealization (the Hardy-Weinberg equilibrium) along the suggested Kantian lines.

Uncalibrated arterial pulse cardiac output measurements in patients with moderately abnormal left ventricular function.

OBJECTIVE: The aim of the study was to evaluate the accuracy and precision of the Vigileo/FloTrac system (Edwards Lifesciences, Irvine, CA) when compared with the intermittent cardiac output and continuous cardiac output measurements obtained from pulmonary arterial catheters in patients with moderately abnormal left ventricular function undergoing elective coronary artery bypass graft surgery. DESIGN: A prospective, observational study. SETTING: Tertiary university hospital. PARTICIPANTS: Twenty patients with moderately abnormal left ventricular function undergoing coronary artery bypass graft surgery were enrolled. MEASUREMENTS AND RESULTS: Data were collected before the induction of anesthesia (T1), after the induction of anesthesia (T2), before cardiopulmonary bypass with an open chest (T3), after cardiopulmonary bypass (T4), after sternal closure (T5), on intensive care unit admission (T6), and at 6 hours (T7) and 12 hours after surgery (T8). A total of 360 data measurements were collected; the mean bias between intermittent cardiac output (ICO) and arterial pressure cardiac output (APCO) was -0.50 ± 1.72 L/min, and the percentage error (PE) was 37.00%. The mean difference between CCO and APCO was -0.06 ± 1.84 L/min, and the PE was 37.80%. The correlation between ΔICO and ΔAPCO was r = 0.7; the correlation between ΔCCO and ΔAPCO was r = 0.73. In the intraoperative period, the mean bias between ICO and APCO was -0.41 ± 1.75 L/min, and the PE was 40.87%. The mean difference between CCO and APCO was -0.18 ± 1.90 L/min, and the PE was 41.48%. In the postoperative period, the mean bias between ICO and APCO was -0.56 ± 1.70 L/min, and the PE was 34.43%. The mean difference between CCO and APCO was -0.36 ± 1.76 L/min, and the PE was 34.87%. CONCLUSIONS: In cardiac surgical patients with moderately abnormal left ventricular function, the Vigileo/FloTrac 2nd generation software sensor device showed mild intraoperative and postoperative agreement when compared with a pulmonary arterial catheter.

Sorin stentless pericardial valve versus Carpentier-Edwards Perimount pericardial bioprosthesis: Is it worthwhile to struggle?

We compared two bovine pericardium prostheses (Sorin Freedom versus Carpentier-Edwards Perimount) in patients with small aortic annulus, randomizing 80 patients affected by prevalent aortic stenosis and studying the residual gradient, the effective orifice area, the left ventricular mass regression and the ventricular function to evaluate the cost-benefit in terms of risk-advantages for the patient.