Lung sonography and recruitment in patients with early acute respiratory distress syndrome: A pilot study

Abstract

IntroductionBedside lung sonography is a useful imaging tool to assess lung aeration in critically ill patients. The purpose of this study was to evaluate the role of lung sonography in estimating the nonaerated area changes in the dependent lung regions during a positive end-expiratory pressure (PEEP) trial of patients with early acute respiratory distress syndrome (ARDS).MethodsTen patients (mean ± standard deviation (SD): age 64 ± 7 years, Acute Physiology and Chronic Health Evaluation II (APACHE II) score 21 ± 4) with early ARDS on mechanical ventilation were included in the study. Transthoracic sonography was performed in all patients to depict the nonaerated area in the dependent lung regions at different PEEP settings of 5, 10 and 15 cm H2O. Lung sonographic assessment of the nonaerated lung area and arterial blood gas analysis were performed simultaneously at the end of each period. A control group of five early ARDS patients matched for APACHE II score was also included in the study.ResultsThe nonaerated areas in the dependent lung regions were significantly reduced during PEEP increases from 5 to 10 to 15 cm H2O (27 ± 31 cm2 to 20 ± 24 cm2 to 11 ± 12 cm2, respectively; P < 0.01). These changes were associated with a significant increase in arterial oxygen partial pressure (74 ± 15 mmHg to 90 ± 19 mmHg to 102 ± 26 mmHg; P < 0.001, respectively). No significant changes were observed in the nonaerated areas in the dependent lung regions in the control group.ConclusionsIn this study, we show that transthoracic lung sonography can detect the nonaerated lung area changes during a PEEP trial of patients with early ARDS. Thus, transthoracic lung sonography might be considered as a useful clinical tool in the management of ARDS patients.

Overview of current lung imaging in acute respiratory distress syndrome

“…Indeed, lung ultrasonography has been demonstrated to be superior to bedside chest radiography not only in the detection, but also in the follow-up, of pneumothorax after pleural drainage [36,41]. Ultrasound was also able to show recruitment of lung parenchyma as PEEP was increased from 5 to 15 cmH 2 O with correlation to improvement of gas exchange [42].…”

Use of Lung Ultrasound to Assess the Efficacy of an Alveolar Recruitment Maneuver in Rabbits With Acute Respiratory Distress Syndrome

“…A subsequent study showed that lung reaeration can be estimated accurately with bedside lung US. 7 Recently, Rode et al 8 proposed that lung US could guide lung recruitment by using PEEP, with improvement in lung consolidation as a sign of improved alveolar ventilation. Presently, there is no systematic USguided lung recruitment protocol available for clinical use.…”

New Diagnostic Capabilities of Ultrasound in the Intensive Care Unit

“…The LAS has been shown in several studies to correlate with changes in lung aeration after pneumonia treatment [21], PEEP titration [23], fluid resuscitation [24 • ], and spontaneous breathing trials [25]. Furthermore, an abbreviated technique of quantifying non-aerated region by planimetry at the dependent region of the right lung along the posterior axillary line has also correlated well with changes in PEEP in a pilot study [26].…”