ScvO2 changes after red-blood-cell transfusion for anaemia in cardiothoracic and vascular ICU patients: an observational study.

BACKGROUND AND OBJECTIVES: Haemoglobin threshold for transfusion has been significantly decreased, but haemoglobin plasma concentration may not be sufficient to assess the need of red-blood-cell (RBC) transfusion. Central venous oxygen saturation (ScvO2 ) is a clue of metabolic matching between O2 transport and consumption, which could help to assess when transfusion is appropriate once anaemia has been diagnosed in ICU patients. MATERIALS AND METHODS: Adult patients admitted consecutively to a cardiothoracic and vascular ICU were included in a prospective, observational and single-centre study over a 6-month period (September 2014 to February 2015), provided they were transfused with RBC. Patients with active bleeding or in unstable condition were excluded. Haemoglobin and ScvO2 were collected through a central venous catheter before and after transfusion. In order to identify a ScvO2 threshold, analysis of ScvO2 changes after transfusion was performed. RESULTS: Fifty-three patients received 100 RBC transfusions. Haemoglobin at the time of transfusion was 7·2 g/dl [6·8-7·7], while ScvO2 was 66·9% [60-73]. A 5% increase in ScvO2 after transfusion has the best specificity and positive predictive values, with a ScvO2 threshold of 65%. After transfusion (RBC units, 2 [1-2]), ScvO2 increased only in patients with ScvO2 ≤65%, from 58% [53-62] to 69% [64-73] (P < 0·001). CONCLUSION: In anaemic patients, RBC transfusion induced a significant increase in ScvO2 , provided it was low before transfusion. A 65% cut-off value of ScvO2 before transfusion showed good specificity and good positive predictive value for a 5% increase after transfusion.

Effect of renal angioembolization on post-traumatic acute kidney injury after high-grade renal trauma: a comparative study of 52 consecutive cases.

BACKGROUND: Acute kidney injury (AKI) is associated with unfavourable outcomes and higher mortality after trauma. Renal angioembolization (RAE) has proved efficiency in the management of high-grade renal trauma (HGRT), but inevitably expose to unavoidable ischaemic areas or contrast medium nephrotoxicity which may impair renal function in the following hours. The aim of this study was to assess the potential acute impact of RAE on renal function in a consecutive series of HGRTs treated nonoperatively. MATERIALS AND METHODS: Of 101 cases of renal trauma admitted to our Regional Trauma Center between January 2005 and January 2010, 52 cases of HGRT were treated nonoperatively; they were retrospectively classified into 2 groups according to whether RAE was used. Incidence and progression of AKI (RIFLE classification), maximum increase in serum creatinine (SCr), level since admission and recovery of renal function at discharge were compared between the groups. Multivariable analysis was performed to determine the role of RAE as an independent risk factor of AKI. RESULTS: RAE was performed in 10 patients within the first 48h. The RAE and no RAE groups were comparable in terms of severity score, renal injury grade, and level of SCr on admission. AKI incidence (RIFLE score Risk or worse) after 48 and 96h was 33% and 10%, respectively and did not differ significantly between groups at 48h (p=1.00) or 96h (p=1.00). The median maximum increase in SCr was significantly higher in no RAE than RAE group (30.4% vs. 6.9%, p=0.04). RAE was not found to be a significant variable in a multiple linear regression analysis predicting maximum SCr rise (p=0.34). SCr at discharge was >120% of baseline in only 5 patients, with no difference according to RAE (p=0.24). CONCLUSION: In a population of nonoperatively treated HGRT, the incidence of AKI decreased from almost 30% to 10% at 48h and 96h. RAE proceeding did not seem to affect significantly the occurrence and course of AKI or renal recovery. The decision to use RAE should probably not be restricted by fear of worsening renal function.