Early Effect of Tidal Volume on Lung Injury Biomarkers in Surgical Patients with Healthy Lungs

Abstract

Background The early biological impact of short-term mechanical ventilation on healthy lungs is unknown. We aimed to characterize the immediate tidal volume (VT)-related changes on lung injury biomarkers in patients with healthy lungs and low risk of pulmonary complications. Methods Twenty-eight healthy patients for knee replacement surgery were prospectively randomized to volume-controlled ventilation with VT 6 (VT6) or 10 (VT10) mL/kg predicted body weight. General anesthesia and other ventilatory parameters (positive end-expiratory pressure 5 cmH2O, FiO2 0.5, respiratory rate titrated for normocapnia) were managed similarly in the two groups. Exhaled breath condensate (EBC) and blood samples were collected for nitrite, nitrate, tumor necrosis factor α, interleukins-1β, 6, 8, 10, 11, neutrophil elastase (NE), and Clara Cell protein 16 (CC16) measurements, at the onset of ventilation and 60 min later. Results No significant differences in biomarkers were detected between the VT groups at any time. The coefficient of variation of EBC nitrite and nitrate decreased in the VT6 but increased in the VT10 group after 60-min ventilation. Sixty minute ventilation significantly increased plasma NE levels in the VT6 (35.2 ± 30.4 vs. 56.4 ± 51.7 ng/mL, P = 0.008) and CC16 levels in the VT10 group (16.4 ± 8.8 vs. 18.7 ± 9.5 ng/mL, P = 0.015). EBC nitrite correlated with plateau pressure (r = 0.27, P = 0.042) and plasma NE (r = 0.44, P = 0.001). Plasma CC16 correlated with compliance (r = 0.34, P = 0.014). Conclusion No tidal volume-related changes were observed in the selected lung injury biomarkers of patients with healthy lungs after 60-min ventilation. Plasma NE and plasma CC16 might indicate atelectrauma and lung distention, respectively.

Exhaled Breath Condensate Nitrate Levels are Inversely Associated with the Body Mass Index of Patients without Respiratory Disease

“…We performed analyses of previously collected samples of exhaled breath condensate (EBC) and plasma obtained from surgical patients without any respiratory disease immediately after the start of mechanical ventilation [31]. These surgical patients had been enrolled in the previously published study on lung injury biomarkers during mechanical ventilation [31].…”

“…Samples of EBC and blood were repeated after 60 minutes in the original study [31], but for the current study on NO-related measurements only 0 minute time point samples were used to avoid 60minute of mechanical ventilation as a potential confounder. For the current study we only included patients with enough remaining volume of EBC and plasma samples for the proposed measurements.…”

“…These surgical patients had been enrolled in the previously published study on lung injury biomarkers during mechanical ventilation [31]. Briefly, study patients were subjected to general anesthesia for elective knee replacement and prospectively randomized to receive volume controlled ventilation with a tidal volume of 6 or 10 mL/kg predicted body weight (PBW) [32] during mechanical ventilation.…”

“…In previously collected samples of EBC and plasma [31], we analyzed and compared nitric oxide and their related pathway metabolites using targeted metabolomics analyses.…”

Computational methods for the analysis of functional 4D-CT chest images.

“…These wider capabilities stem from using the adaptive prior shape model of the lungs to derive more accurate visual appearance descriptions of the chest CT images. The resulting higher accuracy can be beneficial for any current CAD system that uses lung segmentation as a critical initial step for measuring or estimating various biomarkers, such as a whole lung volume, left and right lungs volumes, and so forth [383]. These biomarkers assist in diagnosing many restrictive / obstructive lung diseases, such as interstitial lung disease, chronic obstructive pulmonary disease, extrinsic disorders, and asthma.…”