Jean-Noël Koch

BACKGROUND: Adult cardiac surgery is significantly associated with the development of acute kidney injury (AKI). Still, the incidence and outcomes of AKI vary according to its definition. Our retrospective monocentric study comparatively investigates the yield of RIFLE definition, which is based on the elevation of serum creatinine levels (SCr) or the reduction of urine output (UO), taking into account only one or both criteria. Pre- and per-operative risk factors for post-operative AKI were evaluated. METHODS: All adult patients undergoing cardiac surgery, with or without cardiopulmonary bypass, from April 2008 to March 2009 were included. Clinical, biological and surgical features were recorded. Baseline serum creatinine was determined as its value on day 7 before surgery. Post-operative AKI was diagnosed and scored based upon the highest serum creatinine and/or the lowest urine output. RESULTS: 443 patients (Male/Female ratio, 2.3; median age, 69y) were included, with 221 (49.9%) developing postoperative AKI. Elevated serum creatinine (AKISCr) and oliguria (AKIUO) was observed in 9.7% and 40.2%, respectively. AKI patients had a significantly higher BMI and baseline SCr. In comparison to AKIUO, AKISCr mostly occurred in patients with co-morbidities, and was associated with an increased mortality at 1-year post surgery. CONCLUSIONS: The use of standard RIFLE definition of AKI in a cohort of 443 patients undergoing cardiac surgery resulted in an incidence reaching 50%. Still, significant discrepancies were found between AKISCr and AKIUO regarding the incidence and outcomes. In line with previous reports, our data questions the utility of urine output as a criterion for AKI diagnosis and management after cardiac surgery.

Summary Major vascular surgery is frequently associated with significant blood loss and coagulopathy. Existing evidence suggests hypofibrinogenaemia develops earlier than other haemostatic deficiencies during major blood loss. The purpose of this study was to assess whether the use of an infusion of fibrinogen concentrate to prevent and treat hypofibrinogenaemia during surgery resulted in satisfactory haemostasis, removing or reducing the need for blood component transfusion. Twenty patients undergoing elective extent‐4 thoraco‐abdominal aortic aneurysm repair were randomly allocated to receive either fresh frozen plasma or fibrinogen concentrate to treat hypofibrinogenaemia during surgery. Coagulation was assessed during and after surgery by point‐of‐care and laboratory testing, respectively, and treatment was guided by pre‐defined transfusion triggers. Despite blood losses of up to 11,800 ml in the patients who received the fibrinogen concentrate, none required fresh frozen plasma during surgery, and only two required platelet transfusions. The median ( IQR [range]) allogeneic blood component administration during surgery and in the first 24 h postoperatively was 22.5 (14–28 [2–41]) units in patients allocated to fresh frozen plasma vs. 4.5 (3–11[0–17]) in patients allocated to fibrinogen concentrate (p = 0.011). All patients in both groups were assessed by the surgeon to have satisfactory haemostasis at the end of surgery. Mean ( SD ) postoperative fibrinogen concentrations were similar in patients allocated to fresh frozen plasma and fibrinogen concentrate (1.6 (0.3) g.l −1 vs. 1.6 (0.2) g.l −1 ; p = 0.36) but the mean (SD) international normalised ratio and activated partial thromboplastin time ratio were lower in patients allocated to fresh frozen plasma (1.1 (0.1) vs. 1.8 (0.3); p < 0.0001 and 1.1 (0.2) vs. 1.7 (0.5); p = 0.032, respectively). Fibrinogen concentrate may be used as an alternative to fresh frozen plasma in the treatment of coagulopathy during thoraco‐abdominal aortic aneurysm repair.

Use of a bougie is not without risk, and insertion too far may cause airway injury. We designed a new bougie with a 'traffic light' system to indicate depth of insertion. Forty anaesthetists were randomly assigned to insert either a conventional single-coloured bougie or a novel traffic light bougie. Depth of insertion was measured before and after railroading a tracheal tube. Participants were not informed as to the purpose of the colouring system. The median (IQR [range]) insertion depth of the traffic light bougie was 22 (21-24 [19-27]) cm and for the conventional bougie was 28 (21-32 [20-35]) cm (p = 0.011). Median (IQR [range]) insertion depth after railroading for the traffic light bougie was 25 (25-28 [21-34]) cm and for the conventional bougie was 30.5 (27-35 [23-40]) cm (p = 0.003). This simple colouring system appears to allow intuitive use and significantly reduced the depth of bougie insertion. This system could be also used with other airway exchange devices to improve safety.