无效触发预示着机械通气时间延长。

Ineffective triggering predicts increased duration of mechanical ventilation.

作者信息

de Wit Marjolein, Miller Kristin B, Green David A, Ostman Henry E, Gennings Chris, Epstein Scott K

机构信息

Division of Pulmonary Disease and Critical Care Medicine, Virginia Commonwealth University, Richmond, VA, USA.

出版信息

Crit Care Med. 2009 Oct;37(10):2740-5. doi: 10.1097/ccm.0b013e3181a98a05.

DOI:10.1097/ccm.0b013e3181a98a05

PMID:19886000

Abstract

OBJECTIVES

To determine whether high rates of ineffective triggering within the first 24 hrs of mechanical ventilation (MV) are associated with longer MV duration and shorter ventilator-free survival (VFS).

DESIGN

Prospective cohort study.

SETTING

Medical intensive care unit (ICU) at an academic medical center.

PATIENTS

Sixty patients requiring invasive MV.

INTERVENTIONS

None.

MEASUREMENTS

Patients had pressure-time and flow-time waveforms recorded for 10 mins within the first 24 hrs of MV initiation. Ineffective triggering index (ITI) was calculated by dividing the number of ineffectively triggered breaths by the total number of breaths (triggered and ineffectively triggered). A priori, patients were classified into ITI >or=10% or ITI <10%. Patient demographics, MV reason, codiagnosis of chronic obstructive pulmonary disease (COPD), sedation levels, and ventilator parameters were recorded.

MEASUREMENTS AND MAIN RESULTS

Sixteen of 60 patients had ITI >or=10%. The two groups had similar characteristics, including COPD frequency and ventilation parameters, except that patients with ITI >or=10% were more likely to have pressured triggered breaths (56% vs. 16%, p = .003) and had a higher intrinsic respiratory rate (22 breaths/min vs. 18, p = .03), but the set ventilator rate was the same in both groups (9 breaths/min vs. 9, p = .78). Multivariable analyses adjusting for pressure triggering also demonstrated that ITI >or=10% was an independent predictor of longer MV duration (10 days vs. 4, p = .0004) and shorter VFS (14 days vs. 21, p = .03). Patients with ITI >or=10% had a longer ICU length of stay (8 days vs. 4, p = .01) and hospital length of stay (21 days vs. 8, p = .03). Mortality was the same in the two groups, but patients with ITI >or=10% were less likely to be discharged home (44% vs. 73%, p = .04).

CONCLUSIONS

Ineffective triggering is a common problem early in the course of MV and is associated with increased morbidity, including longer MV duration, shorter VFS, longer length of stay, and lower likelihood of home discharge.

摘要

目的

确定机械通气（MV）开始后24小时内无效触发的高发生率是否与更长的MV持续时间和更短的无呼吸机生存期（VFS）相关。

设计

前瞻性队列研究。

地点

一所学术医疗中心的医学重症监护病房（ICU）。

患者

60例需要有创MV的患者。

干预措施

无。

测量指标

在MV开始后的24小时内，记录患者10分钟的压力-时间和流速-时间波形。无效触发指数（ITI）通过将无效触发呼吸次数除以总呼吸次数（触发和无效触发）来计算。根据预设，患者被分为ITI≥10%或ITI<10%。记录患者的人口统计学资料、MV原因、慢性阻塞性肺疾病（COPD）的合并诊断、镇静水平和呼吸机参数。

测量指标及主要结果

60例患者中有16例ITI≥10%。两组具有相似的特征，包括COPD发生率和通气参数，但ITI≥10%的患者更可能有压力触发呼吸（56%对16%，p = 0.003）且固有呼吸频率更高（22次/分钟对18次，p = 0.03），但两组的设定呼吸机频率相同（9次/分钟对9次，p = 0.78）。调整压力触发因素后的多变量分析还表明，ITI≥10%是MV持续时间更长（10天对4天，p = 0.0004）和VFS更短（14天对21天，p = 0.03）的独立预测因素。ITI≥10%的患者ICU住院时间更长（8天对4天，p = 0.01），住院时间更长（21天对8天，p = 0.03）。两组的死亡率相同，但ITI≥10%的患者出院回家的可能性较小（44%对73%，p = 0.04）。