Neuroendocrine predictors of vasoplegia after cardiopulmonary bypass

PURPOSE

Vasoplegia often complicates on-pump cardiac surgery. Systemic inflammatory response induced by extracorporeal circulation represents the major determinant, but adrenal insufficiency and postoperative vasopressin deficiency may have a role. Pathophysiological meaning of perioperative changes in endocrine markers of hydro-electrolyte balance has not still fully elucidated. Objectives of the present research study were to estimate the incidence of vasoplegia in a homogeneous cohort of not severe cardiopathic patients, to define the role of presurgical adrenal insufficiency, to evaluate copeptin and NT-proBNP trends in the perioperative.

METHODS

We conducted a prospective cohort study in the cardiac intensive care unit of a tertiary referral center. We evaluated 350 consecutive patients scheduled for cardiac surgery; 55 subjects completed the study. Both standard and low-dose corticotropin stimulation tests were performed in the preoperative; copeptin and NT-proBNP were evaluated in the preoperative (T0), on day 1 (T1) and day 7 (T2) after surgery.

RESULTS

Nine subjects (16.3%) developed vasoplegic syndrome with longer bypass and clamping time (p < 0.001). Reduced response to low-dose ACTH test was not associated to vasoplegia. Preoperative copeptin > 16.9 pmol/L accurately predicted the syndrome (AUC 0.86, 95% CI 0.73-0.94; OR 1.17, 95% CI 1.04-1.32). An evident correlation was observed at 7 days postoperative between NT-proBNP and copeptin (r 0.88, 95% CI 0.8-0.93; p < 0.001).

CONCLUSION

Preoperative impaired response to low-dose ACTH stimulation test is not a risk factor for post-cardiotomic vasoplegia; conversely, higher preoperative copeptin predicts the complication. On-pump cardiac surgery could be an interesting model of rapid heart failure progression.

Inhaled nitric oxide versus sodium nitroprusside for preoperative evaluation of pulmonary hypertension in heart transplant candidates

OBJECTIVE

The development of pulmonary hypertension before heart transplantation increases the risk for postoperative right ventricular failure. Reversibility of pulmonary vascular resistance (PVR), which indicates the feasibility of heart transplantation, can be tested with the use of intravenous vasodilators, such as sodium nitroprusside (NaNTP) or prostacyclin. However, the drawback of these drugs is the development of systemic hypotension. The aim of this study was to evaluate the safely and feasibility of inhaled nitric oxide (iNO) compared with sodium nitroprusside to test PVR reversibility, while avoiding systemic hypotension.

MATERIALS AND METHODS

We included all patients who were affected by end stage heart failure undergoing evaluation for heart transplantation if they showed elevated PVR > 2.5 Wood units and mean pulmonary arterial pressure (mPAP) >25 mm Hg. The hemodynamic parameters measured by right heart catheterization were: systolic blood pressure (SBP), mPAP, pulmonary capillary wedge pressure, and cardiac index (CI). The following variables were derived: transpulmonary gradient (TPG) and PVR. All patients were tested by both iNO (20-40 ppm) and intravenous NaNTP, at increasing dosages which were titrated based on systemic pressure. We randomly assigned the order of administration of iNO and NaNTP.

RESULTS

The 9 male candidates has an average age of 56 ± 4 years. Seven of the 9 (71%) had postischemic cardiomyopathy, and 2 had idiopathic cardiomyopathy. We observed a reduction of mPAP (32% and 14%), PVR (41% and 32%), TPG (20% and 26%), and SBP (17% and 5%) and an increase of CI with administration of NaNTP and iNO, respectively.

CONCLUSIONS

We observed a reduction in PVR and mPAP with administration of either iNO and NaNTP. A better effect of NaNTP was attributed to reducted post-load of the left ventricle. However, the main advantage of iNO was the absence of systemic hypotension and its selectivity for pulmonary vascular system, as underscored by TPG reduction.

Mortality reduction in cardiac anesthesia and intensive care: results of the first International Consensus Conference

There is no consensus on which drugs/techniques/strategies can affect mortality in the perioperative period of cardiac surgery. With the aim of identifying these measures, and suggesting measures for prioritized future investigation we performed the first International Consensus Conference on this topic. The consensus was a continuous international internet-based process with a final meeting on 28 June 2010 in Milan at the Vita-Salute University. Participants included 340 cardiac anesthesiologists, cardiac surgeons, and cardiologists from 65 countries all over the world. A comprehensive literature review was performed to identify topics that subsequently generated position statements for discussion, voting, and ranking. Of the 17 major topics with a documented mortality effect, seven were subsequently excluded after further evaluation due to concerns about clinical applicability and/or study methodology. The following topics are documented as reducing mortality: administration of insulin, levosimendan, volatile anesthetics, statins, chronic β-blockade, early aspirin therapy, the use of pre-operative intra-aortic balloon counterpulsation, and referral to high-volume centers. The following are documented as increasing mortality: administration of aprotinin and aged red blood cell transfusion. These interventions were classified according to the level of evidence and effect on mortality and a position statement was generated. This International Consensus Conference has identified the non-surgical interventions that merit urgent study to achieve further reductions in mortality after cardiac surgery: insulin, intra-aortic balloon counterpulsation, levosimendan, volatile anesthetics, statins, chronic β-blockade, early aspirin therapy, and referral to high-volume centers. The use of aprotinin and aged red blood cells may result in increased mortality.

Mortality reduction in cardiac anesthesia and intensive care: results of the first International Consensus Conference

BACKGROUND

There is no consensus on which drugs/techniques/strategies can affect mortality in the perioperative period of cardiac surgery. With the aim of identifying these measures, and suggesting measures for prioritized future investigation we performed the first international consensus conference on this topic.

METHODS

The consensus was a continuous international internet-based process with a final meeting on June 28th 2010 in Milan at the Vita-Salute University. Participants included 340 cardiac anesthesiologists, cardiac surgeons and cardiologists from 65 countries all over the world. A comprehensive literature review was performed to identify topics that subsequently generated position statements for discussion, voting and ranking.

RESULTS

Of the 17 major topics with a documented mortality effect, seven were subsequently excluded after further evaluation due to concerns about clinical applicability and/or study methodology. The following topics are documented as reducing mortality: administration of insulin, levosimendan, volatile anesthetics, statins, chronic beta-blockade, early aspirin therapy, the use of preoperative intra-aortic balloon counterpulsation and referral to high-volume centers. The following are documented as increasing mortality: administration of aprotinin and aged red blood cell transfusion. These interventions were classified according to the level of evidence and effect on mortality and a position statement was generated.

CONCLUSION

This international consensus conference has identified the non-surgical interventions that merit urgent study to achieve further reductions in mortality after cardiac surgery: insulin, intra-aortic balloon counterpulsation, levosimendan, volatile anesthetics, statins, chronic beta-blockade, early aspirin therapy, and referral to high-volume centers. The use of aprotinin and aged red blood cells may result in increased mortality.

The effects of inhaled nitric oxide after lung transplantation

Primary graft failure (PGF) is one of the major complications that occurs immediately following lung transplantation and greatly contributes to increased morbidity and mortality. The incidence of PGF is correlated with a marked decline in endogenous nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) levels. Therefore, the administration of NO during lung transplantation has been proposed as a possible therapeutic treatment to prevent or attenuate PGF pathogenesis. Despite the initial positive results of experimental and uncontrolled clinical trials, recent randomized clinical trials do not support the prophylactic administration of inhaled nitric oxide (iNO) for the prevention of PGF following lung transplantation under the conditions tested. Nonetheless, there is evidence that iNO administration during PGF can improve oxygenation and reduce pulmonary hypertension without altering systemic vascular resistance. This suggests that iNO may prevent the need for extracorporeal membrane oxygenation (ECMO) during the hypoxic phase of PGF. During the intraoperative phase of transplantation, one-lung ventilation (OLV) and pulmonary artery clamping usually increase PVR, causing decreased right ventricular function and hemodynamic instability. The administration of iNO during these lung transplant procedures could decrease right ventricular dysfunction by reducing PVR and help to avoid the use of cardiopulmonary bypass.

Fenoldopam to prevent renal replacement therapy after cardiac surgery. Design of the FENO-HSR study

INTRODUCTION

Acute kidney injury requiring renal replacement therapy is a serious complication following cardiac surgery associated with poor clinical outcomes. Until now no drug showed nephroprotective effects. Fenoldopam is a dopamine-1 receptor agonist which seems to be effective in improving postoperative renal function. The aim of this paper is to describe the design of the FENO-HSR study, planned to assess the effect of a continuous infusion of fenoldopam in reducing the need for renal replacement therapy in patients with acute kidney injury after cardiac surgery.

METHODS

We're performing a double blind, placebo-controlled multicentre randomized trial in over 20 Italian hospitals. Patients who develop acute renal failure defined as R of RIFLE score following cardiac surgery are randomized to receive a 96-hours continuous infusion of either fenoldopam (0.025-0.3 µg/kg/min) or placebo.

RESULTS

The primary endpoint will be the rate of renal replacement therapy. Secondary endpoints will be: mortality, time on mechanical ventilation, length of intensive care unit and hospital stay, peak serum creatinine and the rate of acute renal failure (following the RIFLE score).

CONCLUSIONS

This trial is planned to assess if fenoldopam could improve relevant outcomes in patients undergoing cardiac surgery who develop acute renal dysfunction. Results of this double-blind randomized trial could provide important insights to improve the management strategy of patients at high risk for postoperative acute kidney injury.

Invasive candidiasis and candidemia: new guidelines

Invasive candidiasis (IC) includes candidemia, disseminated candidiasis with deep organ involvement, endocarditis and meningitis. IC has an attributable mortality of 40% to 50% and is increasingly reported in intensive care units (ICUs). Candida albicans and non-albicans strains are both responsible for infections in ICUs, where empirical and targeted treatments especially need to be initially appropriate. This review synthesizes the most recent guidelines for IC and candidemia from an ICU perspective. Essentially, patients who have been previously exposed to azoles have a higher probability of being infected by azole-resistant or non-albicans strains. Infection site, illness severity, neutropenia, hemodynamic status, organ failure and concomitant drug treatments are host-related factors that influence the choice of anti-fungal treatment. In general, echinocandins are currently favored for empiric treatment of candidemia, especially in critically ill patients or those with previous azole exposure. Pharmacokinetic properties and side effects suggest that polyenes should be avoided in patients with renal failure, and that echinocandins and azoles should be avoided in patients with severe hepatic dysfunction.

Partial cation-order and early-stage, phase separation in phase W, Li x Co 1− x O: 0.075≤ x ≤0.24−0.31

We report the characterization using X-ray and neutron powder diffraction, transmission electron microscopy and extended X-ray absorption fine structure of a new, partially ordered rock-salt-like solid solution phase Li x Co 1− x O: 0.075≤ x ≤0.24−0.31. The cation stacking sequence along [111] consists of alternating planes of Co and Co/Li. Nano-sized domains of this cation-ordered phase appear alongside disordered regions; domain size increases from 2 to 8 nm with increasing Li content. Compositions of ordered and disordered regions are Li- and Co-rich, respectively, and, therefore, the phase exhibits frozen-in, incipient phase separation. This microstructure could be considered as a precursor to precipitation of fully ordered, rhombohedral LiCoO 2 .

Evaluation of adaptive support ventilation in paralysed patients and in a physical lung model

OBJECTIVE

Evaluation of the respiratory pattern selected by the Adaptive Support Ventilation (ASV) in ventilated patients with acute, chronic respiratory failure and normal lungs and in a physical lung model.

DESIGN

We tested ASV both on patients and in a physical lung model, with a normal level of minute ventilation and with minute ventilation increased by 30%. In each patient, respiratory pattern, mechanics and blood gases were recorded.

SETTING

General ICU of a University Hospital.

RESULTS

In patients with normal lungs, mean values+/-SD were: tidal volume (Vt) 558.1+/-142.4 mL, respiratory rate (RR) 12.6+/-1.3b/min and inspiratory time/total time ratio (Ti/Ttot) 42.4+/-4.1%; in COPD, mean values+/-SD were: Vt 724+/-171 mL, RR 9.2+/-2.7b/min and Ti/Ttot 26.6+/-10.5%; in restrictive ones, mean values+/-SD were: Vt 550.2+/-77.0 mL, RR 15.8+/-2.6b/min, Ti/Ttot 47.5+/-2.5%. In the lung model, at a normal setting, mean values+/-SD were: Vt 523+/-18.5 mL, RR 14+/-0.0b/min, Ti/Ttot 44.0%, in COPD, mean values+/-SD were: Vt 678+/-0.0 mL, RR 9+/-0.0b/min, Ti/Ttot 20+/-0.7%, in restrictive one, mean values+/-SD were: Vt 513+/-12.8 mL, RR 15+/-0.0b/min, Ti/Ttot 48+/-1.5%. In model hyperventilation conditions in a normal setting a Vt of 582+/-16.6 mL, RR 16+/-0.0b/min, Ti/Ttot 48+/-0.0% were selected, in the obstructive setting Vt 883+/-0.0 mL, RR 9+/-0.0b/min, Ti/Ttot 20+/-0.0% and in a restrictive one Vt 545+/-8.4 mL, RR 18+/-0.0b/min, Ti/Ttot 50-0.0%.

CONCLUSIONS

In normal patients ASV selected a ventilatory pattern close to the physiological one, in COPD almost a high expiratory time pattern and in restrictive ones a reduced tidal volume pattern. In the model the selection was similar. In the hyperventilation test, ASV chose a balanced increase in both Vt and RR.