Neumonía asociada a la ventilación mecánica (NAVM): factores de riesgo relacionados con la presencia de gérmenes multirresistentes(AU) / Ventilator-associated pneumonia: risk factors associated with the presence of multiresistant organism

La Neumonía Asociada a la Ventilación Mecánica (NAVM) afecta entre 10 por ciento y 65 por ciento de los pacientes, con una mortalidad atribuible que fluctúa entre 24 por ciento y 76 por ciento. Numerosas directrices recomiendan dividir la NAVM en precoz si ocurre dentro de las primeras 96 horas de ingreso a UCI o tardía si es posterior, ya que las tardías suelen ser ocasionadas por patógenos multirresistentes (PMR). Objetivo: Determinar si hay asociación entre la presencia de PMR con la NAVM tardía, uso previo de antibióticos, comorbilidady gravedad al ingreso a la UCI. Métodos: Estudio prospectivo de 12 meses. El diagnóstico de NAVM fue clínico asociado a cultivo cuantitativo en contaje significativo (106 UFC/ml para cultivo cuantitativo de aspirado endotraqueal, 104 UFC/ml para lavado broncoalveolar (LBA) vía broncoscópica). Resultados: Se enrolaron 48 pacientes con NAVM consecutivos, 19 mujeres, la edad promedio fue de 59+/-18,5 años. Los principales gérmenes involucrados fueron St Aureus meticilino resistente (54 por ciento), Acinetobacter sp (33 por ciento) y Pseudomonas aeruginosa (19 por ciento). El aislamiento de PMR no se asoció significativamente a la NAVM tardía (p >0,05), por el contrario el uso previo de antibióticos se relacionó más estrechamente con la presencia de PMR (p <0,0001). Al analizar variables clínicas sólo la escala de Glasgow más baja al ingreso a la UCI se asoció significativamente con la presencia de PMR (10,7+/-3,3 vs14,5+/-0,5, p <0,05). Conclusión: El uso previo de antibióticos se asocia significativamente a la neumonía por PMR independiente del momento en que se diagnostica la NAVM.

Ventilator-associated pneumonia (VAP) is a mechanical ventilation complication that affects about 10 percent to 65 percent of mechanical ventilated patients. The attributable mortality ranged between 24 percent to 76 percent. Most of the guidelines have recommended to classify VAP in early onset if diagnosis is made in the first 96 hours from ICU admission or late onset if the diagnosis is later. Early onset VAP is reported to be due to antibiotic-sensitive pathogens, while late-onset VAP is frequently attributed to antibiotic-resistant pathogens (ARP). The Aim of the study was to correlate the isolate of ARP with late-onset VAP, prior antimicrobial treatment, comorbidity and severity of illnesses. Methods: 12 months prospective study. VAP was define according a presumptive clinical diagnosis plus an isolation of a pathogen in a significant concentration (>106 CFU/ml for quantitative cultures of endotracheal aspirates, >104 CFU/ml for bronchoalveolar lavage from fiberoptic bronchoscopic). Results:We included 48 patients with VAP, 19 women, the average age was 59 +/- 18,5 years. 75 percent (36/48) were late-onset VAP. The organism most frequently isolated was methicillin resistant S. aureus (54 percent), Acinetobacter sp (33 percent), and Pseudomona aeruginosa (19 percent). ARP was not associated with late-onset VAP (p >0,05), by contrast prior antimicrobial treatment was closely associated to isolation of ARP (p<0,001). When analyzed clinical variables only lower Glasgow coma scale at ICU admission was associated with ARP-VAP (10,7+/-3,3 vs 14,5+/-0,5 p <0,05). Conclusion: Prior antimicrobial treatment was closely associated with ARP-VAP regardless of the timing of VAP Diagnosis.

A Comparative Study of Endotracheal Aspirates and Protected Specimen Brush in the Quantitative Cultures of the Ventilator-Associated Pneumonia / 결핵

BACKGROUND: Pneumonia is a frequent complication in patients undergoing mechanical ventilation. Quantitative culture of protected specimen brush(PSB) have shown satisfactory diagnostic accuracy for the diagnosis of ventilator-associated pneumonia. However PSB method is invasive, expensive, and require a bronchoscopic procedure. But endotracheal aspiration(EA) is simple and less expensive. The purpose of our study was to investigate the diagnosic value of EA quantitative cultures. METHOD: We studied 15 cases of ventilator-associated pneumonia(for >72h of mechanical ventilation) patients. Patients were divided into two diagnostic categories. Group I was the patients who were suspicious of clinical pneumonia, Group II was the patients for control. The obtained samples by EA and PSB were homogenized for quantitative culture with a calibrated loop method in all patients. RESULT: Using 103cfu/ml, 105cfu/ml as threshold in quantitative culture of PSB, EA respectively, we found that EA quantitative cultures represented a relatively sentive(70%) and relatively specific (60%) method to diagnose the ventilator-associated pneumonia. CONCLUSION: Although EA quantitative cultures are less specific than PSB for diagnosing ventilator-associated pneumonia. EA quantitative cultures correlated with PSB quantitative culture in patients with clinical pneumonia and may be used to treat these patients when bronchoscopic procedures are not available.