'Early' and 'late' timing for renal replacement therapy in acute kidney injury after cardiac surgery: a prospective, interventional, controlled, single-centre trial.

OBJECTIVES: Acute kidney injury after cardiac surgery (CS-AKI) is strongly associated with in-hospital mortality and morbidity. We aimed to investigate whether 'early' or 'late' initiation of renal replacement therapy (RRT) in patients with CS-AKI is associated with a survival benefit or more favourable outcomes. METHODS: All patients who had undergone cardiac surgery at 'Ospedali Riuniti' of Ancona from July 2011 to February 2013 were prospectively enrolled and divided into two treatment groups: the 'early' approach was used during the first 10 months, and the 'late' approach during the next 10 months. 'Early' RRT was started after 6 h of urine output less than 0.5 ml/kg/h, whereas in the 'late' group, therapy started on the basis of persistent (>12 h) oliguria. A total of 1658 patients were enrolled in the trial. The primary outcome was operative mortality, and the secondary outcomes were length of intensive care unit and hospital stay. RESULTS: The total number of patients treated with RRT was 59 (3.6%): 46 (5.5%) in the 'early' group and 13 (1.6%) in the 'late' group (P < 0.0001). Although RRT was significantly less utilized in the 'late' group, no significant difference in the primary and secondary outcomes was found, but a trend towards a better outcome in the 'late' group was observed. Furthermore, we found a significant difference in mortality between the two approaches in the subgroups of patients with preoperative renal dysfunction and in patients suffering from CS-AKI with a clear advantage of the late strategy. CONCLUSIONS: Our results do not support the use of early RRT in CS-AKI. CLINICAL TRIAL REGISTRATION: This trial is registered in the clinicaltrial.gov registry: NCT01961999.

Epidural anesthesia in elderly patients undergoing coronary artery bypass graft surgery.

OBJECTIVES: The purpose of this study was to evaluate the effects of thoracic epidural anesthesia on postoperative N-terminal pro B-natriuretic peptide (NT-proBNP) release in elderly patients undergoing elective coronary artery bypass graft (CABG) surgery. DESIGN: A case-matched, nonrandomized study. SETTING: A university hospital, single institution. PARTICIPANTS: 46 consecutive and 46 control patients. INTERVENTIONS: Ninety-two elderly patients (>65 years old) undergoing elective CABG surgery were recruited. Forty-six patients receiving general and epidural anesthesia were case matched (preoperative medications, ejection fraction, and comorbidities) with 46 control subjects receiving general anesthesia. The primary outcome measure was postoperative NT-proBNP release. The preoperative or intraoperative variables significantly associated with an intensive care unit stay longer than 4 days were determined by logistic regression. MEASUREMENTS AND MAIN RESULTS: The median (interquartile range) plasma concentrations of NT-proBNP before surgery were 402 (115-887 pg/mL) in the epidural group versus 508 (228-1,285 pg/mL) in the general anesthesia group (p = 0.9), whereas 24 hours after surgery it increased to 1846 (1,135-3,687 pg/mL) versus 5,005 (2,220-11,377 pg/mL) (p = 0.001), respectively. There were more patients (p = 0.043) in the control group (9/46 = 19.5%) than in the thoracic epidural anesthesia group (4/46 = 8.8%) with an intensive care unit stay longer than 4 days. The absence of preoperative beta-blocker therapy (odds ratio = 3.94; 95% confidence interval, 1.123-13.833; p =0.03) and of an epidural catheter (odds ratio = 3.91; 95% confidence interval, 1.068-14.619; p = 0.04) were the only preoperative and intraoperative variables independently associated with a prolonged intensive care unit stay. CONCLUSIONS: Epidural anesthesia added to general anesthesia for CABG surgery significantly attenuates NT-proBNP release in elderly patients and reduces the incidence of prolonged intensive care unit stay.

Management and decision-making strategy for systolic anterior motion after mitral valve repair.

OBJECTIVE: Systolic anterior motion can complicate mitral valve repair. It can have no clinical consequence or cause low cardiac output syndrome and hypotension. The management of systolic anterior motion in the operating room remains controversial: some groups advocate nonsurgical management, and others propose immediate surgical correction. Conventional hemodynamic measures require time and can be unsuccessful. While describing our experience, we propose a simple and innovative management and classification of this complication. METHODS: Presenting the data of 608 consecutive patients who underwent mitral valve repair for degenerative mitral valve disease, we describe a novel 2-step conservative management consisting of intravascular volume expansion and discontinuation of inotropic drug (step 1) and increasing afterload by means of ascending aortic manual compression while administering beta-blockers (step 2). We also describe a novel classification of systolic anterior motion: easy to revert (responding to step 1), difficult to revert (responding to step 2), or persistent. RESULTS: The overall incidence of systolic anterior motion was 9.8% (60/608): 40 patients had easy-to-revert systolic anterior motion, and 15 had difficult-to-revert systolic anterior motion. Five patients had a persistent condition and underwent surgical intervention within 48 hours. CONCLUSIONS: Systolic anterior motion after repair of a degenerative mitral valve is common. Surgical revision in the minority of patients unresponsive to standard conservative management is suggested.

N-terminal B-natriuretic Peptide after coronary artery bypass graft surgery.

OBJECTIVE: To investigate N-terminal amino-acid sequence of the B-natriuretic peptide (NT-proBNP) release and its prognostic characteristics after coronary artery bypass graft surgery with and without cardiopulmonary bypass. DESIGN: Observational study. SETTING: Teaching hospital. PARTICIPANTS: One hundred eighty-four patients. INTERVENTIONS: The authors determined plasma concentrations of NT-proBNP just before anesthesia induction and 24 hours after the end of the surgery. MEASUREMENTS AND MAIN RESULTS: NT-proBNP concentrations (median [interquartile range]) increased from 270 (75-716) pg/mL preoperatively to 1,664 (978-3,193) pg/mL on postoperative day 1 (p < 0.001), and all postoperative values were higher than the preoperative ones. NT-proBNP concentrations at day 1 were correlated to those at day 0 (r(2) = 0.34, p < 0.001). Patients showing elevated concentration of cTnI at day 1 (>14 ng/mL) had significantly (p = 0.04) higher plasma NT-proBNP levels than patients with a low cardiac troponin I concentration. Patients with prolonged intensive care unit (ICU) stay (>4 days) showed at day 1 significantly higher (p = 0.003) plasma NT-proBNP levels than patients with ICU stay <4 days. Elevated NT-proBNP at day 1 was significantly (p = 0.001) associated with in-hospital mortality, 18,584 (11,896-29,158) pg/mL versus 1,597 (965-3,034) pg/mL in survivors. CONCLUSIONS: The present results show, for the first time, that postoperative NT-proBNP levels are associated with in-hospital mortality and prolonged ICU stay after CABG surgery. These findings support the prognostic value of postoperative plasma levels of NT-proBNP.

Temperature management during off-pump coronary artery bypass graft surgery: a randomized clinical trial on the efficacy of a circulating water system versus a forced-air system.

OBJECTIVE: The aim of this study was to evaluate the performance of a new temperature management system specifically designed for cardiac surgery (Allon ThermoWrapping Thermoregulation System; MTRE Advanced Technologies Ltd, Or Akiva, Israel) using a circulating-water garment and to compare it with a conventional forced-air cover system in order to determine whether it could reduce the incidence of perioperative hypothermia during off-pump coronary artery bypass graft (OPCAB) surgery. DESIGN: Prospective, randomized. SETTING: University, tertiary care hospital. PARTICIPANTS: Thirty-one patients undergoing primary OPCAB surgery. INTERVENTIONS: Patients undergoing OPCAB surgery were randomized into the new thermoregulation system, Allon (study group, n = 15), and the standard forced-air system, Bair Hugger (Sterile Cardiac Access blanket Model 645; Augustine SA, Berne, Switzerland) (control group, n = 16). MEASUREMENTS AND MAIN RESULTS: Rectal temperature was recorded each 30 minutes during surgery and at intensive care unit arrival. Patients in the study group had higher temperatures than the control group at all time points, and the difference reached statistical significance after 2 hours of surgery. Moreover, fewer patients in the study group suffered perioperative hypothermia (defined as rectal temperature <36 degrees C) than the control group (2/15 patients (13.3%) in the study group v 13/16 (81.3%) in the control group [p = 0.0006]). No difference in other outcomes was noted. None of the patients died in the hospital. There were no adverse events reported. CONCLUSIONS: The circulating-water garment, Allon ThermoWrapping Thermoregulation System, maintained normothermia during OPCAB surgery better than forced-air systems, especially after the first 2 hours of surgery, and it was not associated with surgical field disturbance.

The incidence and risk of acute renal failure after cardiac surgery.

OBJECTIVE: To evaluate outcome and risk factors of acute renal failure in a surgical population with or without preoperative renal dysfunction. DESIGN: Observational study. SETTING: Intensive care unit at a University Hospital. PARTICIPANTS: Five thousand sixty-eight consecutive adult patients who underwent cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Perioperative variables measured were age, sex, basic pathology, preoperative renal impairment defined as creatinine >1.4 mg/dL, ventricular dysfunction, preoperative neurologic event, chronic obstructive pulmonary disease, diabetes, type of surgery, use of intra-aortic balloon pump (IABP), cardiopulmonary bypass (CPB) duration, redo or emergency surgery, hemorrhage, blood transfusion, surgical revisions, and postoperative complications. MEASUREMENTS AND MAIN RESULTS: Acute renal failure (100% creatinine increase) developed in 171 (3.4%) patients, whereas 94 patients (1.9% of the population) had renal replacement therapy. Hospital mortality was 40.9% in patients with acute renal failure and increased to 63.8% when renal replacement therapy was requested. Sex, age, emergency surgery, low ejection fraction, IABP device, redo, diabetes, mitral valve surgery, CPB duration, and preoperative renal disease were independently associated with acute renal failure at a multivariate analysis. CONCLUSION: This study confirms that acute renal failure is one of the major complications of cardiac surgery, identifies the risk factors, and suggests that optimizing cardiac output and reducing CPB time could improve the outcome of patients at high risk of acute renal failure.