Ferrer Miquel, Ioanas Malina, Arancibia Francisco, Marco Maria Angeles, de la Bellacasa Jorge Puig, Torres Antoni
Servei de Pneumologia, Unitat de Cures Intensives i Intermèdies, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain.
Crit Care Med. 2005 Sep;33(9):2003-9. doi: 10.1097/01.ccm.0000178185.50422.db.
Abnormal airway colonization in patients with chronic obstructive pulmonary disease (COPD) needing invasive mechanical ventilation (IMV) is considered a first step in the acquisition of nosocomial pneumonia. Noninvasive ventilation (NIV) could potentially avoid this, but airway colonization has not been studied in patients who undergo NIV. We hypothesized that patients undergoing NIV would have lower rates of colonization than patients undergoing IMV. The aim of the study was to assess the microbial airway colonization in patients with exacerbated COPD needing NIV and IMV.
A 2-yr prospective cohort study.
Respiratory intensive and intermediate care unit.
Eighty-six patients with exacerbated COPD undergoing NIV on admission (64 successes and 22 failures, according to subsequent intubation), and 51 patients undergoing IMV on admission.
Quantitative culture specimens of sputum or tracheal aspirate were collected on admission and at follow-up (day 3) during NIV or IMV, respectively. Clinical assessment, including severity scores, and arterial blood gas measurements were also determined.
Compared with the NIV-success group, colonization by potentially pathogenic microorganisms was greater in the NIV-failure group on admission (13 [59%] vs. 14 [22%]; p < .001) and at follow-up while patients still underwent NIV (14 [93%] vs. 7 [14%]; p < .001), and it was even higher than during IMV at follow-up (20 [50%]; p = .027). Colonization by nonfermenting Gram-negative bacilli, mainly Pseudomonas aeruginosa, was significantly associated with NIV failure on admission (OR, 5.6; p = .016) and at follow-up (OR, 23.5; p < .001). Moreover, colonization by these microorganisms at follow-up (OR, 8.8; p = .008) and inadequate antimicrobial treatment (OR 11.3; p = .001) were associated with increased hospital mortality.
Airway colonization by nonfermenting Gram-negative bacilli is strongly associated with NIV failure. Because it occurs before intubation, this would be a marker rather than just a consequence of NIV failure necessitating intubation. The efficacy of decreasing airway colonization in preventing NIV failure needs to be assessed.
对于需要有创机械通气（IMV）的慢性阻塞性肺疾病（COPD）患者，气道定植异常被认为是获得医院获得性肺炎的第一步。无创通气（NIV）可能会避免这种情况，但尚未对接受NIV的患者的气道定植情况进行研究。我们假设接受NIV的患者的定植率低于接受IMV的患者。本研究的目的是评估需要NIV和IMV的COPD急性加重患者的气道微生物定植情况。
一项为期2年的前瞻性队列研究。
呼吸重症和中级护理病房。
86例入院时接受NIV的COPD急性加重患者（根据随后的插管情况，64例成功，22例失败），以及51例入院时接受IMV的患者。
分别在入院时以及NIV或IMV期间的随访（第3天）时采集痰液或气管吸出物的定量培养标本。还进行了包括严重程度评分在内的临床评估以及动脉血气测量。
与NIV成功组相比，NIV失败组在入院时（13例[59%]对14例[22%]；p<0.001）以及随访期间患者仍在接受NIV时（14例[93%]对7例[14%]；p<0.001）潜在致病微生物的定植情况更严重，并且在随访时甚至高于IMV期间（20例[50%]；p=0.027）。非发酵革兰氏阴性杆菌（主要是铜绿假单胞菌）的定植在入院时（比值比[OR]，5.6；p=0.016）和随访时（OR，23.5；p<0.001）与NIV失败显著相关。此外，随访时这些微生物的定植（OR，8.8；p=0.008）和抗菌治疗不足（OR 11.3；p=0.001）与医院死亡率增加相关。
非发酵革兰氏阴性杆菌的气道定植与NIV失败密切相关。由于它发生在插管之前，这将是一个标志物，而不仅仅是需要插管引发的NIV失败的结果。需要评估降低气道定植在预防NIV失败方面的效果。
