1. Computed tomography assessment of PEEP-induced alveolar recruitment in patients with severe COVID-19 pneumonia
- Author
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Ball, L., Robba, C., Maiello, L., Herrmann, J., Gerard, S. E., Xin, Y., Battaglini, D., Brunetti, I., Minetti, G., Seitun, S., Vena, A., Giacobbe, D. R., Bassetti, M., Rocco, P. R. M., Cereda, M., Castellan, L., Patroniti, N., Pelosi, P., Gratarola, A., Loconte, M., Molin, A., Orefice, G., Iannuzzi, F., Costantino, F., Battioni, D., Bovio, G., Buconte, G., Casaleggio, A., Cittadini, G., Dogliotti, L., Giasotto, V., Pigati, M., Santacroce, E., Zaottini, F., Dentone, C., Taramasso, L., Magnasco, L., Valbusa, A., and Bastianello, M.
- Subjects
Male ,CT scan ,medicine.medical_specialty ,ARDS ,medicine.medical_treatment ,Respiratory system mechanics ,Critical Care and Intensive Care Medicine ,Severity of Illness Index ,law.invention ,Cohort Studies ,Positive-Pressure Respiration ,03 medical and health sciences ,0302 clinical medicine ,Mechanical ventilation ,Interquartile range ,law ,Internal medicine ,Severity of illness ,medicine ,Humans ,COVID-19 ,Aged ,Female ,Italy ,Middle Aged ,Pneumonia, Viral ,Pulmonary Alveoli ,Tomography, X-Ray Computed ,Treatment Outcome ,Viral ,030212 general & internal medicine ,Respiratory system ,Tomography ,business.industry ,lcsh:Medical emergencies. Critical care. Intensive care. First aid ,030208 emergency & critical care medicine ,Pneumonia ,Oxygenation ,lcsh:RC86-88.9 ,respiratory system ,medicine.disease ,Intensive care unit ,X-Ray Computed ,respiratory tract diseases ,Cardiology ,business ,circulatory and respiratory physiology - Abstract
Background There is a paucity of data concerning the optimal ventilator management in patients with COVID-19 pneumonia; particularly, the optimal levels of positive-end expiratory pressure (PEEP) are unknown. We aimed to investigate the effects of two levels of PEEP on alveolar recruitment in critically ill patients with severe COVID-19 pneumonia. Methods A single-center cohort study was conducted in a 39-bed intensive care unit at a university-affiliated hospital in Genoa, Italy. Chest computed tomography (CT) was performed to quantify aeration at 8 and 16 cmH2O PEEP. The primary endpoint was the amount of alveolar recruitment, defined as the change in the non-aerated compartment at the two PEEP levels on CT scan. Results Forty-two patients were included in this analysis. Alveolar recruitment was median [interquartile range] 2.7 [0.7–4.5] % of lung weight and was not associated with excess lung weight, PaO2/FiO2 ratio, respiratory system compliance, inflammatory and thrombophilia markers. Patients in the upper quartile of recruitment (recruiters), compared to non-recruiters, had comparable clinical characteristics, lung weight and gas volume. Alveolar recruitment was not different in patients with lower versus higher respiratory system compliance. In a subgroup of 20 patients with available gas exchange data, increasing PEEP decreased respiratory system compliance (median difference, MD − 9 ml/cmH2O, 95% CI from − 12 to − 6 ml/cmH2O, p p = 0.003), increased PaO2 with FiO2 = 0.5 (MD 24 mmHg, 95% CI from 12 to 51 mmHg, p 2 with FiO2 = 1.0 (MD 7 mmHg, 95% CI from − 12 to 49 mmHg, p = 0.313). Moreover, alveolar recruitment was not correlated with improvement of oxygenation or venous admixture. Conclusions In patients with severe COVID-19 pneumonia, higher PEEP resulted in limited alveolar recruitment. These findings suggest limiting PEEP strictly to the values necessary to maintain oxygenation, thus avoiding the use of higher PEEP levels.
- Published
- 2021