Evaluation of autologous retransfusion from a closed suction drainage system for patient blood management in elective total hip and knee replacement: A two cohort study.

BACKGROUND: Postoperative autologous retransfusion of drainage blood might reduce the transfusion of red blood cell concentrates after major orthopaedic surgery. OBJECTIVES: Our primary objective was to evaluate the effectiveness of a blood collection and retransfusion system. Secondary objectives included safety issues and the quality of the drainage blood collected. DESIGN: Combined retrospective and prospective cohort study. SETTING: Swiss regional hospital, from 1 January to 31 December 2015 (retrospective cohort) and 1 January to 31 August 2018 (prospective cohort). PATIENTS: The retrospective and prospective cohort included 216 and 46 patients, respectively, who underwent elective hip or knee replacement. INTERVENTIONS: Use of a postoperative blood collection and retransfusion system. MAIN OUTCOME MEASURES: The primary outcome was the postoperative haemoglobin in patients with and without autotransfusion. Secondary outcomes were percentage of patients with transfusion of allogeneic blood products and with adverse events with and without autotransfusion. Tertiary outcomes were laboratory levels of specific inflammation and coagulation parameters in collected drain blood directly after surgery and 6 h postoperatively. RESULTS: Autologous retransfusion was performed in 50 patients (23%) in the retrospective analysis. Postoperative haemoglobin level was increased by 5 g dl (P = 0.017) in retransfused patients compared with those without retransfusion. However, there was no difference in the number of transfused allogeneic red blood cell concentrates. Mild adverse transfusion reactions were reported in 13 retransfused patients (26%). Laboratory analyses for the second prospective part detected massively elevated concentrations of myeloperoxidase and IL-6 in the drainage blood, but C-reactive protein and procalcitonin concentrations were within normal ranges at both time points. D-dimers levels were above the upper normal level in 37 and 24% at the two time points, respectively, and tended to decrease over time (P = 0.060). CONCLUSION: Our study questions the effectiveness of postoperative autotransfusion as part of a patient blood management programme. In addition, the obvious signs of inflammatory reactions and coagulation activation raise safety concerns. TRIAL REGISTRATION: The cohort study was not registered in a trial registry.

Diagnostic and prognostic value of the D-dimer test in emergency department patients: secondary analysis of an observational study.

Background D-dimer measurement improves the rule-out of thromboembolic disease. However, little is known about the risk of false positive results for the diagnosis of thromboembolic disease and its prognostic value. Herein, we investigated factors influencing the accuracy of D-dimer and its prognostic value in a large cohort of emergency department (ED) patients. Methods This is a secondary analysis of a prospective observational single center, cohort study. Consecutive patients, for whom a D-dimer test was requested by the treating physician, were included. Associations of clinical parameters on admission with false positive D-dimer results for the diagnosis of thromboembolic disease were investigated with logistic regression analysis. Results A total of 3301 patients were included, of which 203 (6.1%) had confirmed thromboembolic disease. The negative and positive predictive values of the D-dimer test at the 0.5 mg/L cut-off were 99.9% and 11.4%, respectively. Several factors were associated with positive D-dimer results potentially falsely indicating thromboembolic disease in multivariate analysis including advanced age (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.04-1.05, p < 0.001), congestive heart failure (CHF) (OR 2.79, 95% CI 1.77-4.4, p < 0.01), renal failure (OR 2.00, 95% CI 1.23-3.24, p = 0.005), history of malignancy (OR 2.6, 95% CI 1.57-4.31, p < 0.001), C-reactive protein (CRP) (OR 1.02, 95% CI 1.01-1.02, p < 0.001) and glomerular filtration rate (GFR) (OR 0.99, 95% CI 0.99-1.00, p = 0.003). Regarding its prognostic value, D-dimer was associated with a 30-day mortality (adjusted OR 1.05, 95% CI 1.02-1.09, p = 0.003) with an area under the curve (AUC) of 0.79. Conclusions While D-dimer allows an accurate rule-out of thromboembolic disease, its positive predictive value in routine ED patients is limited and largely influenced by age, comorbidities and acute disease factors. The strong prognostic value of D-dimer in this population warrants further investigation.

Perioperative Myocardial Injury After Noncardiac Surgery: Incidence, Mortality, and Characterization.

BACKGROUND: Perioperative myocardial injury (PMI) seems to be a contributor to mortality after noncardiac surgery. Because the vast majority of PMIs are asymptomatic, PMI usually is missed in the absence of systematic screening. METHODS: We performed a prospective diagnostic study enrolling consecutive patients undergoing noncardiac surgery who had a planned postoperative stay of ≥24 hours and were considered at increased cardiovascular risk. All patients received a systematic screening using serial measurements of high-sensitivity cardiac troponin T in clinical routine. PMI was defined as an absolute high-sensitivity cardiac troponin T increase of ≥14 ng/L from preoperative to postoperative measurements. Furthermore, mortality was compared among patients with PMI not fulfilling additional criteria (ischemic symptoms, new ECG changes, or imaging evidence of loss of viable myocardium) required for the diagnosis of spontaneous acute myocardial infarction versus those that did. RESULTS: From 2014 to 2015 we included 2018 consecutive patients undergoing 2546 surgeries. Patients had a median age of 74 years and 42% were women. PMI occurred after 397 of 2546 surgeries (16%; 95% confidence interval, 14%-17%) and was accompanied by typical chest pain in 24 of 397 patients (6%) and any ischemic symptoms in 72 of 397 (18%). Crude 30-day mortality was 8.9% (95% confidence interval [CI], 5.7-12.0) in patients with PMI versus 1.5% (95% CI, 0.9-2.0) in patients without PMI (P<0.001). Multivariable regression analysis showed an adjusted hazard ratio of 2.7 (95% CI, 1.5-4.8) for 30-day mortality. The difference was retained at 1 year with mortality rates of 22.5% (95% CI, 17.6-27.4) versus 9.3% (95% CI, 7.9-10.7). Thirty-day mortality was comparable among patients with PMI not fulfilling any other of the additional criteria required for spontaneous acute myocardial infarction (280/397, 71%) versus those with at least 1 additional criterion (10.4%; 95% CI, 6.7-15.7, versus 8.7%; 95% CI, 4.2-16.7; P=0.684). CONCLUSIONS: PMI is a common complication after noncardiac surgery and, despite early detection during routine clinical screening, is associated with substantial short- and long-term mortality. Mortality seems comparable in patients with PMI not fulfilling any other of the additional criteria required for spontaneous acute myocardial infarction versus those patients who do. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02573532.