title: Performance and impact of a rapid method combining mass spectrometry and direct antimicrobial susceptibility testing on treatment adequacy of patients with ventilator-associated pneumonia.
abstract: Inappropriate antibiotic therapy in ventilator-associated pneumonia (VAP) is associated with increased mortality. Using broad-spectrum antibiotics for 48 h until the results of conventional cultures and antimicrobial susceptibility testing (AST) are available, may promote the emergence of drug-resistant bacteria. Performing AST directly on clinical respiratory samples would hasten the process by at least 24 h. Here, we analysed the diagnostic performance of a rapid method combining mass spectrometry and direct AST (DAST), and compared it with the conventional method (mass spectrometry with conventional AST (CAST)). Additionally, we assessed its potential impact on antimicrobial use in patients. Over a period of 18 months, the two methods were performed on 85 bronchoalveolar lavages obtained from intensive care unit patients with suspected VAP, and in which Gram-negative bacilli were observed on direct examination. Only the CAST results were reported to the clinicians. DAST produced useable results in 85.9% of the patients. The sensitivity and negative predictive values of DAST were 100% for all antibiotics tested, except gentamicin (97.1%, (95% CI 93.3-101) and 97.4% (93.7-101), respectively) and amikacin (88.9% (81.7-96.1) and 96.4% (92.1-100.7), respectively), compared with CAST. Specificity and positive predictive values ranged from 82.9 (74.2-91.5) to 100%, and from 86.4 (78.5-94.2) to 100%, respectively. If the DAST results had been reported to the clinicians, treatment could have been optimized 24 h earlier in 35/85 (41.2%) patients, with 17 carbapenem patient-days saved. Overall, routine use of the DAST method could help optimize earlier antibiotic treatment in patients with suspected VAP.
authors: Réanimation médicale et infectieuse, Hôpital Bichat, Paris, France.
authors: M
authors: M
authors: Le Dorze
authors: Département Epidémiologie et Recherche Clinique, AP-HP, Hôpital Bichat, Paris, France; INSERM CIE 801, Paris, France; UMR 1123 ECEVE, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors: N
authors: N
authors: Gault
authors: Réanimation médicale et infectieuse, Hôpital Bichat, Paris, France.
authors: A
authors: A
authors: Foucrier
authors: Laboratoire de Bactériologie, AP-HP, Hôpital Bichat, Paris, France; UMR 1137, INSERM, IAME, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors: E
authors: E
authors: Ruppé
authors: Réanimation médicale et infectieuse, Hôpital Bichat, Paris, France; UMR 1137, INSERM, IAME, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors: B
authors: B
authors: Mourvillier
authors: Laboratoire de Bactériologie, AP-HP, Hôpital Bichat, Paris, France.
authors: P L
authors: PL
authors: Woerther
authors: UMR 1137, INSERM, IAME, Université Paris Diderot, Sorbonne Paris Cité, Paris, France; Unité hospitalière de lutte contre les infections nosocomiales, Hôpital Bichat, Paris, France.
authors: G
authors: G
authors: Birgand
authors: Réanimation chirurgicale, Hôpital Bichat, Paris, France.
authors: P
authors: P
authors: Montravers
authors: Réanimation chirurgicale cardio-vasculaire, AP-HP, Hôpital Bichat, Paris, France.
authors: M P
authors: MP
authors: Dilly
authors: Département Epidémiologie et Recherche Clinique, AP-HP, Hôpital Bichat, Paris, France; INSERM CIE 801, Paris, France; UMR 1123 ECEVE, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors: F
authors: F
authors: Tubach
authors: Laboratoire de Bactériologie, AP-HP, Hôpital Bichat, Paris, France; UMR 1137, INSERM, IAME, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors: A
authors: A
authors: Andremont
authors: Réanimation médicale et infectieuse, Hôpital Bichat, Paris, France; UMR 1137, INSERM, IAME, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors: J F
authors: JF
authors: Timsit
authors: Réanimation médicale et infectieuse, Hôpital Bichat, Paris, France; UMR 1137, INSERM, IAME, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors: M
authors: M
authors: Wolff
authors: Laboratoire de Bactériologie, AP-HP, Hôpital Bichat, Paris, France; UMR 1137, INSERM, IAME, Université Paris Diderot, Sorbonne Paris Cité, Paris, France. Electronic address: laurence.armand-lefevre@bch.aphp.fr.
authors: L
authors: L
authors: Armand-Lefèvre
mesh_terms: D000368:Aged; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D008826:Microbial Sensitivity Tests / Q000379:methods*; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000188:drug therapy*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013997:Time Factors
keywords: Antibiotic resistance; carbapenem; direct antimicrobial susceptibility testing; intensive care unit; ventilator-associated pneumonia