A multifaceted strategy to optimize pharmacokinetics of antimicrobial therapy in patients with hospital-acquired infections-a monocentre quality improvement project.

OBJECTIVE: We assessed the efficacy of a quality improvement programme to optimize the delivery of antimicrobial therapy in critically ill patients with hospital-acquired infections (HAI). PATIENTS AND METHODS: Before-after trial in a university hospital in France. Consecutive adults receiving systemic antimicrobial therapy for HAI were included. Patients received standard care during the pre-intervention period (June 2017 to November 2017). The quality improvement programme was implemented in December 2017. During the intervention period (January 2018 to June 2019), clinicians were trained to dose adjustment based on therapeutic drug monitoring and continuous infusion of ß-lactam antibiotics. The primary endpoint was the mortality rate at day 90. RESULTS: A total of 198 patients were included (58 pre-intervention, 140 intervention). The compliance with the therapeutic drug monitoring-dose adaptation increased from 20.3% to 59.3% after the intervention (P < 0.0001). The 90-day mortality rate was 27.6% in the pre-intervention period and 17.3% in the intervention group (adjusted relative risk 0.53, 95%CI 0.27-1.07, P = 0.08). Treatment failures were observed in 22 (37.9%) patients before and 36 (25.7%) patients after the intervention (P = 0.07). CONCLUSIONS: Recommendations for therapeutic drug monitoring-dose adaptation and continuous infusion of ß-lactam antibiotics were not associated with a reduction in the 90-day mortality rate in patients with HAI.

Efficacy and tolerability of a cocktail of bacteriophages to treat burn wounds infected by Pseudomonas aeruginosa (PhagoBurn): a randomised, controlled, double-blind phase 1/2 trial.

BACKGROUND: Wound infections are the main cause of sepsis in patients with burns and increase burn-related morbidity and mortality. Bacteriophages, natural bacterial viruses, are being considered as an alternative therapy to treat infections caused by multidrug-resistant bacteria. We aimed to compare the efficacy and tolerability of a cocktail of lytic anti-Pseudomonas aeruginosa bacteriophages with standard of care for patients with burns. METHODS: In this randomised phase 1/2 trial, patients with a confirmed burn wound infection were recruited from nine burn centres in hospitals in France and Belgium. Patients were eligible if they were aged 18 years or older and had a burn wound clinically infected with P aeruginosa. Eligible participants were randomly assigned (1:1) by use of an interactive web response system to a cocktail of 12 natural lytic anti-P aeruginosa bacteriophages (PP1131; 1 × 106 plaque-forming units [PFU] per mL) or standard of care (1% sulfadiazine silver emulsion cream), both given as a daily topical treatment for 7 days, with 14 days of follow-up. Masking of treatment from clinicians was not possible because of the appearance of the two treatments (standard of care a thick cream, PP1131 a clear liquid applied via a dressing), but assignments were masked from microbiologists who analysed the samples and patients (treatment applied while patients were under general anaesthetic). The primary endpoint was median time to sustained reduction in bacterial burden by at least two quadrants via a four-quadrant method, assessed by use of daily swabs in all participants with a microbiologically documented infection at day 0 who were given at least one sulfadiazine silver or phage dressing (modified intention-to-treat population). Safety was assessed in all participants who received at least one dressing according to protocol. Ancillary studies were done in the per-protocol population (all PP1131 participants who completed 7 days of treatment) to assess the reasons for success or failure of phage therapy. This trial is registered with the European Clinical Trials database, number 2014-000714-65, and ClinicalTrials.gov, number NCT02116010, and is now closed. FINDINGS: Between July 22, 2015, and Jan 2, 2017, across two recruitment periods spanning 13 months, 27 patients were recruited and randomly assigned to receive phage therapy (n=13) or standard of care (n=14). One patient in the standard of care group was not exposed to treatment, giving a safety population of 26 patients (PP1131 n=13, standard of care n=13), and one patient in the PP1131 group did not have an infection at day 0, giving an efficacy population of 25 patients (PP1131 n=12, standard of care n=13). The trial was stopped on Jan 2, 2017, because of the insufficient efficacy of PP1131. The primary endpoint was reached in a median of 144 h (95% CI 48-not reached) in the PP1131 group versus a median of 47 h (23-122) in the standard of care group (hazard ratio 0·29, 95% CI 0·10-0·79; p=0·018). In the PP1131 group, six (50%) of 12 analysable participants had a maximal bacterial burden versus two (15%) of 13 in the standard of care group. PP1131 titre decreased after manufacturing and participants were given a lower concentration of phages than expected (1 × 102 PFU/mL per daily dose). In the PP1131 group, three (23%) of 13 analysable participants had adverse events versus seven (54%) of 13 in the standard of care group. One participant in each group died after follow-up and the deaths were determined to not be related to treatment. The ancillary study showed that the bacteria isolated from patients with failed PP1131 treatment were resistant to low phage doses. INTERPRETATION: At very low concentrations, PP1131 decreased bacterial burden in burn wounds at a slower pace than standard of care. Further studies using increased phage concentrations and phagograms in a larger sample of participants are warranted. FUNDING: European Commission: Framework Programme 7.

Empiric antimicrobial therapy for ventilator-associated pneumonia after brain injury.

Issues regarding recommendations on empiric antimicrobial therapy for ventilator-associated pneumonia (VAP) have emerged in specific populations.To develop and validate a score to guide empiric therapy in brain-injured patients with VAP, we prospectively followed a cohort of 379 brain-injured patients in five intensive care units. The score was externally validated in an independent cohort of 252 brain-injured patients and its extrapolation was tested in 221 burn patients.The multivariate analysis for predicting resistance (incidence 16.4%) showed two independent factors: preceding antimicrobial therapy ≥48 h (p<0.001) and VAP onset ≥10 days (p<0.001); the area under the receiver operating characteristic curve (AUC) was 0.822 (95% CI 0.770-0.883) in the learning cohort and 0.805 (95% CI 0.732-0.877) in the validation cohort. The score built from the factors selected in multivariate analysis predicted resistance with a sensitivity of 83%, a specificity of 71%, a positive predictive value of 37% and a negative predictive value of 96% in the validation cohort. The AUC of the multivariate analysis was poor in burn patients (0.671, 95% CI 0.596-0.751).Limited-spectrum empirical antimicrobial therapy has low risk of failure in brain-injured patients presenting with VAP before day 10 and when prior antimicrobial therapy lasts <48 h.

Perineal burn care: French working group recommendations.

OBJECTIVES: Burns to the perineum are frequently exposed to faeces. Diverting colostomy is often described to prevent faecal soiling. Because this technique is invasive with frequent complications, use of non-surgical devices including specifically designed faecal management systems has been reported in perineal burns. METHODS: In order to standardise the faecal management strategy in patients with perineal burns, a group of French experts was assembled. This group first evaluated the ongoing practice in France by analysing a questionnaire sent to every French burn centre. Based on the results of this study and on literature data, the experts proposed recommendations on the management of perineal burns in adults. RESULTS: Specifically designed faecal management systems are the first-line method to divert faeces in perineal burns. The working group proposed recommendations and an algorithm to assist in decisions in the management of perineal burns in four categories of patients, depending on total burn skin area, depth and extent of the perineal burn. CONCLUSION: In France, non-surgical devices are the leading means of faecal diversion in perineal burns. The proposed algorithm may assist in decisions in the management of perineal burns. The expert group emphasises that large clinical studies are needed to better evaluate these devices.

Antibiotics and the burn patient.

Infection is a major problem in burn care and especially when it is due to bacteria with hospital-acquired multi-resistance to antibiotics. Moreover, when these bacteria are Gram-negative organisms, the most effective molecules are 20 years old and there is little hope of any new product available even in the distant future. Therefore, it is obvious that currently available antibiotics should not be misused. With this aim in mind, the following review was conducted by a group of experts from the French Society for Burn Injuries (SFETB). It examined key points addressing the management of antibiotics for burn patients: when to use or not, time of onset, bactericidia, combination, adaptation, de-escalation, treatment duration and regimen based on pharmacokinetic and pharmacodynamic characteristics of these compounds. The authors also considered antibioprophylaxis and some other key points such as: infection diagnosis criteria, bacterial inoculae and local treatment. French guidelines for the use of antibiotics in burn patients have been designed up from this work.

Klebsiella pneumoniae clinical isolate coproducing SHV-2a, DHA-1, QnrB4, and AAC(6')-Ib-cr determinants in France.

We report on a Klebsiella pneumoniae clinical isolate coproducing bla(DHA-1), bla(SHV-2a), qnrB4, and aac(6')-Ib-cr genes. Molecular analysis demonstrated the presence of this combination on the same large plasmid. Despite a negative result for extended-spectrum beta-lactamase (ESBL) by Vitek2(R) system (bioMérieux, Marcy-l'Etoile, France), an ESBL was detected by a double-disk test. Phenotypic techniques and molecular analysis are key approaches to determine coresistance.

Influence of glomerular filtration rate on the clearance of vancomycin administered by continuous infusion in burn patients.

The relationship between clearance of vancomycin administered by continuous infusion and the glomerular filtration rate (GFR) estimated by creatinine clearance (CL(Cr)) was investigated in a large cohort of burn patients. Individual vancomycin clearance (CL(Van)) was estimated from the ratio between the rate of infusion and the plasma concentration at steady state for 70 patients (149 samples). The average value of CL(Van) (7.03+/-3.79 L/h) was higher than normal values in non-burn patients. A significant relationship between CL(Van) versus CL(Cr) was found (r=0.506; P<0.001): CL(Van) (L/h)=0.0205CL(Cr)(mL/min)+3.47. From this result, a simple formula is proposed to adapt vancomycin dosage: rate of vancomycin continuous infusion (g/day)=[0.0205CL(Cr) (mL/min)+3.47] x [target vancomycin concentration at steady state (mg/L)] x (24/1000). The limits of the predictive performance of this formula are discussed, since factors other than GFR can affect vancomycin elimination. This formula could help clinicians to define the optimum vancomycin dosage, particularly in patients with disturbed renal function.

Effect of systematic empiric treatment with imipenem on the bacterial ecology in a burns unit.

This study took place over 18 months and was divided into three 6 month periods. During the first and third periods, the bacterial ecology of the unit was reviewed, including the observation of bacteria which were isolated and led us to prescribe general antimicrobial therapy, and record the subsequent antibiograms that became available. During the second 6 month period, any patient developing an infection due (or possibly due) to a "Gram negative" strain received imipenem (as beta lactam antimicrobial agent), usually combined with tobramycin. The comparison between bacteria and antibiograms isolated during the first and the third periods did not show any increase in multiple resistant bacteria or imipenem resistant strains, including methicillin resistant Staphylococcus aureus (MRSA). During the third period, in comparison with the first, the number of Pseudomonas aeruginosa and Acinetobacter strains was lower; however, the number of Enterobacter and Klebsiella had increased. There was an increase of overall resistance to ticarcillin, but there was no increase in resistance to the other antimicrobials concerned in the study. Therefore, we concluded that wide use of imipenem did not impair the bacterial ecology of the unit, if used with precautions such as high dose regimen, de-escalation, and both pharmacokinetics and ecology monitoring.