Goel Varun, Hogade Sumati A, Karadesai Sg
Department of Microbiology, Jawaharlal Nehru Medical College, Belgaum, Karnataka, India.
Indian J Anaesth. 2012 Nov;56(6):558-62. doi: 10.4103/0019-5049.104575.
Ventilator-associated pneumonia (VAP) is a common complication of ventilatory support for patients with acute respiratory failure and is associated with increased morbidity and mortality.
The present study was undertaken to do quantitative cultures of aerobic bacteria, perform the antibiotic susceptibility testing from the endotracheal aspirates and clinical outcome of the clinically suspected patients of VAP.
A prospective study was performed over a period of one year in a tertiary care hospital, enrolling patients on mechanical ventilation (MV) for ≥48 hr. Endotracheal aspirates (ETA) were collected from patients with suspected VAP, and direct gram's stain criteria was used to accept the sample. Quantitative cultures of ETA were performed with the threshold for microbiological diagnosis of VAP was taken as ≥10(5) colony forming units (cfu)/ml.
Out of 53 cases, 2 (3.77%) were polymicrobial. Multidrug resistant bacteria, mainly Acinetobacter baumannii 49.09% (27/55) and Pseudomonas aeruginosa 30.91% (17/55) were the most common pathogens isolated. Metallo-beta lactamases (MBLs) was produced by 47.06% (8/17) of Pseudomonas aeruginosa and 62.96% (17/27) of Acinetobacter baumannii.
The bacteriological approach for the management of VAP helps the clinicians in choosing the appropriate antibiotics. This study showed that quantitative cultures of endotracheal aspirate at a cutoff point of 10(5) cfu/ml is one of the alternative to bronchoscopy in the diagnosis of clinically suspected ventilator associated pneumonia.
呼吸机相关性肺炎（VAP）是急性呼吸衰竭患者机械通气支持常见的并发症，与发病率和死亡率增加相关。
本研究旨在对需氧菌进行定量培养，对气管内吸出物进行药敏试验，并观察临床疑似VAP患者的临床结局。
在一家三级医院进行了为期一年的前瞻性研究，纳入机械通气（MV）≥48小时的患者。从疑似VAP患者中收集气管内吸出物（ETA），并采用直接革兰氏染色标准接受样本。对ETA进行定量培养，将VAP微生物学诊断阈值设定为≥10⁵菌落形成单位（cfu）/ml。
53例病例中，2例（3.77%）为多种微生物感染。分离出的最常见病原体是多重耐药菌，主要是鲍曼不动杆菌49.09%（27/55）和铜绿假单胞菌30.91%（17/55）。47.06%（8/17）的铜绿假单胞菌和62.96%（17/27）的鲍曼不动杆菌产生金属β-内酰胺酶（MBL）。
VAP管理的细菌学方法有助于临床医生选择合适的抗生素。本研究表明，气管内吸出物定量培养，以10⁵ cfu/ml为临界值，是临床疑似呼吸机相关性肺炎诊断中支气管镜检查的替代方法之一。
