Jesus Ruiz

Utilidad de la procalcitonina para el diagnóstico de infección en el paciente crítico con cirrosis hepática

OBJECTIVE To evaluate the usefulness of procalcitonin (PCT) for diagnosing infection in patients with liver cirrhosis admitted to an Intensive Care Unit. DESIGN A retrospective study was carried out. SCOPE Intensive Care Unit. Versatile, twenty-four beds. Participants Patients with liver cirrhosis admitted to our Intensive Care Unit in the last four years with suspected infection and measurement of PCT. RESULTS Among the 255 patients with cirrhosis admitted to our unit, PCT was determined for the differential diagnosis of infection in 69 cases (27%). Three patients were excluded from analysis due to a lack of clinical data. The average stay was 10.6 ± 9.2 days, with a mortality rate of 65%. The origin of cirrhosis was mainly viral (57%) or alcoholic (37%). The Child-Pugh and MELD scores were 9.5 ± 2 and 23 ± 8, respectively. Infection was diagnosed in 54 patients (82%). The most common infection was pneumonia (72%), followed by intraabdominal infections (18%) and bacteremia (5%). In patients without infection, the median PCT concentration was 0.57 ng/ml (range 0.28 to 1.14) versus 2.99 (1.31 to 9.4) in those with infection (p<.001). Diagnostic capacity was maintained in patients with intraabdominal infections. The diagnostic cutoff point was set at 0.8 ng/ml (sensitivity 83%, specificity 75%, AUC 0.82 [0.702-0.93]). CONCLUSIONS In patients with liver cirrhosis, PCT is useful for identifying bacterial infections, including intraabdominal processes.

Impact of amikacin pharmacokinetic/pharmacodynamic index on treatment response in critically ill patients

OBJECTIVES This study evaluated the association between the pharmacokinetic/pharmacodynamic index and treatment response to amikacin in critically ill patients. METHODS An observational prospective study was designed. Critically ill adult patients with infection due to amikacin-sensitive Gram-negative bacteria treated with amikacin were included. Amikacin maximum (Cmax) and minimum (Cmin) plasma concentration samples were taken during the first 48-96h after the beginning of treatment. The impact of Cmax/MIC ratio and area under the concentration-time curve (AUC)/MIC ratio on early and final clinical response, microbiological eradication, development of resistant strains and renal toxicity was analysed using a multivariate model. RESULTS A total of 85 patients received amikacin treatment, of whom 71 (83.5%) achieved a Cmax/MIC >6, 66 (77.6%) a Cmax/MIC >8, 64 (75.3%) a Cmax/MIC >10 and 72 (84.7%) an AUC/MIC >65. Clinical response at the end of treatment was significantly greater in patients with Cmax/MIC >6 [OR=5.48 (95% CI 1.28-11.40)], Cmax/MIC >8 [OR=6.01 (2.41-12.2)] and Cmax/MIC >10 [OR=8.02 (2.21-14.2)]. Cmax/MIC >10 was associated with a non-significant increase in microbiological eradication [OR=2.84 (0.76-10.61)]. Achieving Cmax/MIC >6 was associated with a lower proportion of patients with selection of resistant strains or with an increase in amikacin MIC (27.8% vs. 10.2%). Amikacin AUC was associated with development of nephrotoxicity [ROC curve 0.77 (0.66-0.87)]. CONCLUSIONS The Cmax/MIC ratio of amikacin in critically ill patients is directly related to the response to treatment and the selection of resistant strains.

Vancomycin and daptomycin minimum inhibitory concentrations as a predictor of outcome of methicillin-resistant Staphylococcus aureus bacteraemia

OBJECTIVES The aim of this study was to determine the persistence of the adverse prognostic effect of elevated vancomycin minimum inhibitory concentration (MIC) in methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in a setting with low vancomycin use. METHODS A retrospective study focusing on episodes of bacteraemia due to MRSA diagnosed from January 2010 through December 2015 was designed. The main outcome measures were 30-day mortality and treatment failure. Multivariate logistic regression analysis was used to identify variables associated with patient mortality and treatment outcome. RESULTS In total, 79 MRSA bacteraemia episodes were included. The vancomycin MIC was >1.0μg/mL in 53 episodes (67.1%). The presence of high vancomycin MIC was not associated with a higher mortality rate or treatment success. A daptomycin MIC≥0.5μg/mL was present in 16 (26.2%) of 61 episodes for which the daptomycin MIC was obtained and was associated with 30-day mortality in the multivariate analysis (odds ratio=4.72, 95% confidence interval 1.19-18.71). None of the antimicrobials used were associated with a lower risk of treatment failure or mortality. CONCLUSIONS The pernicious effect of high vancomycin MIC disappears in the absence of a predominant use of this antibiotic. However, a high daptomycin MIC in MRSA bacteraemia is associated with higher mortality in patients with bacteraemia, irrespective of antimicrobial treatment choice.

Individualised antimicrobial dosing in critically ill patients undergoing continuous renal replacement therapy: focus on total drug clearance

Background Continuous renal replacement therapy (CRRT) is common practice in critical care patients with acute renal failure. Objectives To evaluate the adequacy of antimicrobial doses calculated based on the total drug clearance and dose recommended by different guides in critically ill patients undergoing CRRT. Methods Retrospective observational study. Patients admitted to a critical care unit during May 2014 to May 2016 and subjected to CRRT were included. The recommended dose was established as the product of the usual dose of the drug by total drug clearance. Results 177 antimicrobial agents, used in 64 patients were analysed; 45 (25.4%) antimicrobials were given in an insufficient dose (<20%) according to the theoretical calculation. Following the recommendations in the revised guidelines, between 10% and 20% of antimicrobials were given in insufficient doses. A higher success rate of treatment in those patients not receiving a low drug dosage was seen (35.2% vs 24.0%). Conclusions There is a great disparity between the antimicrobial dose prescribed, recommended and calculated based on drug clearance in critically ill patients undergoing CRRT.