No abstract

Objectives Acute kidney injury is a frequent complication of cardiac surgery and increases morbidity and mortality. As preoperative biomarkers predicting the development of acute kidney injury are not available, we have tested the hypothesis that preoperative plasma levels of endogenous ouabain may function as this type of biomarker. Rationale and Design Endogenous ouabain is an adrenal stress hormone associated with adverse cardiovascular outcomes. Its involvement in acute kidney injury is unknown. With studies in patients and animal settings, including isolated podocytes, we tested the above mentioned hypothesis. Patients Preoperative endogenous ouabain was measured in 407 patients admitted for elective cardiac surgery and in a validation population of 219 other patients. We also studied the effect of prolonged elevations of circulating exogenous ouabain on renal parameters in rats and the influence of ouabain on podocyte proteins both “in vivo” and “in vitro.” Main Results In the first group of patients, acute kidney injury (2.8%, 8.3%, 20.3%, p < 0.001) and ICU stay (1.4 ± 0.38, 1.7 ± 0.41, 2.4 ± 0.59 days, p = 0.014) increased with each incremental preoperative endogenous ouabain tertile. In a linear regression analysis, the circulating endogenous ouabain value before surgery was the strongest predictor of acute kidney injury. In the validation cohort, acute kidney injury (0%, 5.9%, 8.2%, p < 0.0001) and ICU stay (1.2 ± 0.09, 1.4 ± 0.23, 2.2 ± 0.77 days, p = 0.003) increased with the preoperative endogenous ouabain tertile. Values for preoperative endogenous ouabain significantly improved (area under curve: 0.85) risk prediction over the clinical score alone as measured by integrate discrimination improvement and net reclassification improvement. Finally, in the rat model, elevated circulating ouabain reduced creatinine clearance (–18%, p < 0.05), increased urinary protein excretion (+ 54%, p < 0.05), and reduced expression of podocyte nephrin (–29%, p < 0.01). This last finding was replicated ex vivo by incubating podocyte primary cell cultures with low-dose ouabain. Conclusions Preoperative plasma endogenous ouabain levels are powerful biomarkers of acute kidney injury and postoperative complications and may be a direct cause of podocyte damage.

No abstract

We identified 15 treatments that decreased/increased mortality in critically ill patients in 24 multicenter randomized controlled trials. However, design affected trial size and larger trials were more likely to show harm. Finally, clinicians view of such trials and their translation into practice varied.

No abstract

Protective ventilation is a feasible alternative to traditional ventilation during elective neurosurgery.

Introduction. Post-operative pain control improves surgical outcome and many hospitals created multidisciplinary teams, called "Acute Pain Services" (APS). We collected APS data on 10,760 adult patients over a five year period, including complications, side effects and patient satisfaction.

Intra-aortic balloon pump (IABP) is an established tool in the management of cardiac dysfunction in cardiac surgery. The best timing for IABP weaning is unknown and varies greatly among cardiac centers. The authors investigated the differences in IABP management among 66 cardiac surgery centers performing 40,675 cardiac surgery procedures in the 12-month study period. The centers were contacted through email, telephone, or in person interview. IABP management was very heterogeneous in this survey: In 43% centers it was routinely removed on the first postoperative day, and in 34% on the second postoperative day. In 50% centers, it was routinely removed after extubation of the patients whereas in 15% centers it was removed while the patients were sedated and mechanically ventilated. In 66% centers, patients were routinely receiving pharmacological inotropic support at the time of removal of IABP. The practice of decreasing IABP support was also heterogeneous: 57% centers weaned by reducing the ratio of beat assistance whereas 34% centers weaned by reducing balloon volume. We conclude that the management of IABP is heterogeneous and there is a need for large prospective studies on the management of IABP in cardiac surgery.