BackgroundThe benefits of cardiac surgery are sometimes difficult to predict and the decision to operate on a given individual is complex. Machine Learning and Decision Curve Analysis (DCA) are recent methods developed to create and evaluate prediction models.Methods and findingWe conducted a retrospective cohort study using a prospective collected database from December 2005 to December 2012, from a cardiac surgical center at University Hospital. The different models of prediction of mortality in-hospital after elective cardiac surgery, including EuroSCORE II, a logistic regression model and a machine learning model, were compared by ROC and DCA. Of the 6,520 patients having elective cardiac surgery with cardiopulmonary bypass, 6.3% died. Mean age was 63.4 years old (standard deviation 14.4), and mean EuroSCORE II was 3.7 (4.8) %. The area under ROC curve (IC95%) for the machine learning model (0.795 (0.755–0.834)) was significantly higher than EuroSCORE II or the logistic regression model (respectively, 0.737 (0.691–0.783) and 0.742 (0.698–0.785), p < 0.0001). Decision Curve Analysis showed that the machine learning model, in this monocentric study, has a greater benefit whatever the probability threshold.ConclusionsAccording to ROC and DCA, machine learning model is more accurate in predicting mortality after elective cardiac surgery than EuroSCORE II. These results confirm the use of machine learning methods in the field of medical prediction.

BackgroundFew data are available on the impact of levosimendan in refractory cardiogenic shock patients undergoing peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO). The aim of this study was to evaluate the impact of levosimendan on VA-ECMO weaning in patients hospitalized in intensive care unit (ICU).MethodsThis retrospective cohort study was conducted in a French university hospital from 2010 to 2017. All patients hospitalized in ICU undergoing VA-ECMO were consecutively evaluated.ResultsA total of 150 patients undergoing VA-ECMO were eligible for the study. Thirty-eight propensity-matched patients were evaluated in the levosimendan group and 65 in the non-levosimendan group. In patients treated with levosimendan, left ventricular ejection fraction had increased from 21.5 ± 9.1% to 30.7 ± 13.5% (P < 0.0001) and aortic velocity–time integral from 8.9 ± 4 cm to 12.5 ± 3.8 cm (P = 0.002) 24 h after drug infusion. After propensity score matching, levosimendan was the only factor associated with a significant reduction in VA-ECMO weaning failure rates (hazard ratio = 0.16; 95% confidence interval 0.04–0.7; P = 0.01). Kaplan–Meier survival curves showed that survival rates at 30 days were 78.4% for the levosimendan group and 49.5% for the non-levosimendan group (P = 0.02). After propensity score matching analysis, the difference in 30-day mortality between the two groups was not significant (hazard ratio = 0.55; 95% confidence interval 0.27–1.10; P = 0.09).ConclusionsOur results suggest that levosimendan was associated with a beneficial effect on VA-ECMO weaning in ICU patients.

Little is known about cannula-related infection (CRI) in patients supported by extracorporeal membrane oxygenation (ECMO). The aim of this study was to assess the incidence, the risk factors, prognosis, and microbiological characteristics of CRI in patients supported by ECMO. This retrospective cohort study was conducted in one intensive care unit (ICU). Among 220 consecutive patients with peripheral ECMO, 39 (17.7%) developed CRI. The incidence of CRI was 17.2 per 1,000 ECMO days. The main isolated microorganisms were Enterobacteriaceae (38%), Staphylococcus spp. (28.2%; 8.5% were methicillin-sensitive Staphylococcus aureus and 19.7% were coagulase-negative staphylococci), and Pseudomonas aeruginosa (18.3%). Bacteremia was present in 23 cases (59.7%). In multivariate analysis, the risk factors for CRI were longer ECMO duration (p = 0.006) and higher Simplified Acute Physiology Score 2 (p = 0.004). Forty-one percentage of patients with CRI needed surgical management of the infected site. Cannula-related infection was not associated with higher in-hospital mortality (p = 0.73), but it was associated with a longer stay in ICU (p < 0.0001) and a longer stay in hospital (p = 0.002). In conclusion, CRI is frequent in patients with ECMO and associated with a longer stay in hospital. Risk factors for CRI were longer ECMO duration and higher Simplified Acute Physiology Score 2. Concomitant bacteremia was frequent (59.7%) and CRI should be strongly investigated in cases of positive blood culture.

BackgroundThe therapeutic effect of aminoglycosides is highest and optimal when the peak plasma concentration (C max)/minimal inhibitory concentration (MIC) ratio is between 8 and 10. The French guidelines recommend to use high doses of aminoglycosides for empiric antibiotic therapy in patients suffering from severe sepsis or septic shock. In clinical practice, the recommended target is an amikacin C max between 60 and 80 mg/L, which corresponds to approximately 8 times the MIC breakpoint, as defined by the European Committee on Antimicrobial Susceptibility Testing. The aim of this study was to assess the incidence and impact on mortality of an amikacin concentration between 60 and 80 mg/L in patients suffering from severe sepsis or septic shock.MethodsThis was a prospective observational cohort study conducted in two intensive care units (ICU). Patients receiving amikacin at a loading dose of 30 mg/kg for severe sepsis or septic shock were enrolled in the cohort. The target C max for amikacin was between 60 and 80 mg/L, as recommended by French guidelines (i.e. C max/MIC breakpoint = 8–10).ResultsOver the study period, the amikacin C max was <60 mg/L, between 60 and 80 mg/L, and >80 mg/L in 20 (18.2%), 46 (41.8%) and 44 (40%) of the 110 selected patients, respectively. Mortality rate was 40, 28.3 and 56.8% in the groups of patients with C max < 60 mg/L, 60 mg/L < C max < 80 mg/L and C max > 80 mg/L, respectively. Following multivariate analysis, mortality rate was significantly lower in the group of patients with amikacin C max between 60 and 80 mg/L than in the group of patients with amikacin C max > 80 mg/L (P = 0.004). The multivariate analysis also revealed that the factors independently associated with a higher in-ICU mortality rate were age (P = 0.02) and norepinephrine dose (P = 0.0001).Conclusions With a loading dose of 30 mg/kg of amikacin, concentration was potentially suboptimal (C max < 60 mg/L) in only 18.2% of patients. The pharmacodynamic target (60 mg/L < C max < 80 mg/L) recommended by French guidelines was reached in 41.8% of patients and was associated with reduced in-ICU mortality. But amikacin overexposure (i.e. C max > 80 mg/L) was frequent and potentially associated with increased mortality.

The mortality of severe leptospirosis is lower than for other bacterial infection, provided modern resuscitation techniques are available. Prompt organ support ensures very low mortality rates despite high severity scores.