Avaliação da exposição a antibióticos profiláticos na ocorrência de pneumonia associada à ventilação mecânica precoce em pacientes vítimas de trauma cranioencefálico: uma coorte retrospectiva

Abstract

Ventilator-associated pneumonia (VAP) is defined as a pulmonary parenchymal infection that occurs at least 48 hours after the start of invasive mechanical ventilation (IMV). VAP represents a frequent complication in patients hospitalized in the Intensive Care Unit (ICU), with an impact on mortality and costs. It can be classified as early if it occurs up to 96 hours from the beginning of the ventilatory support, or late. The use of preemptive antibiotics in comatose patients may prevent early VAP, but there is no evidence of benefit in other relevant clinical outcomes. On the other hand, exposure to antibiotics may alter bacterial colonization, result in increased costs and promote infection by multiresistant bacteria. Prophylactic antibiotics are commonly administered to patients after major trauma. The objective of this study was to evaluate the association between the administration of prophylactic antimicrobials in the first 24 hours of hospital admission and the occurrence of early VAP in patients with acute severe and moderate traumatic brain injury. We studied a retrospective cohort of patients admitted to the Adult ICU of the Hospital João XXIII of the Fundação Hospitalar do Estado de Minas Gerais - FHEMIG, in Belo Horizonte, Minas Gerais. Between 01/Jan/2016 and 30/Aug/2016, 907 patients were admitted to the Adult CTI and 231 were included in the study, with a mean age of 41.0 years and 81.2% were males. On average, VAP was diagnosed 6.34 (2.95) days after the start of mechanical ventilation in 196 patients. Of these, 97 with positive cultures and 34 caused by multiresistant bacteria. The patients were divided into two groups: Group 24h, patients who did not use prophylactic antibiotics or who used prophylactic antibiotics for less than 24h (123; 53.2%) and Group >24h, patients who used prophylactic antibiotics for more than 24h (108, 46.8%). The Group >24h had a lower frequency of early VAP (19.4% vs. 36.6%, p=0.004), shorter hospital stay (44,8 vs. 61,1 days, p=0,035) and a higher incidence of multiresistant bacteria in the first episode of VAP in 14 days (48.6% vs. 27.4%, p=0.036), when compared to the 24h Group. Among patients admitted with ECG 3 to 8, subjects in the Group >24h had less episodes of early VAP (18.5% vs. 38.5%, p=0.004) and fewer tracheostomies (53.2% vs. 69.5%, p=0.027). Patients with an ECG 9 to 12 in the Group >24h had more multiresistant bacteria as the etiologic agent of VAP (85.4% vs. 21.4%, p=0.016). In a multivariate analysis, Group >24h (OR 0.47 IC95% 0.25, 0.87 p=0.016) was the only statistically significant variable associated to a lower occurrence of early VAP. In conclusion, in the studied population, the higher exposure to prophylactic antibiotics was associated with a lower occurrence of early VAP, especially in patients with ECG 3 to 8, and to a higher frequency of multiresistant bacteria in the first episode of VAP.