Monitoring dead space during recruitment and PEEP titration in an experimental model
2006 (English)In: Intensive Care Medicine, ISSN 0342-4642, E-ISSN 1432-1238, Vol. 32, no 11, 1863-1871 p.Article in journal (Refereed) Published
Objective: To test the usefulness of dead space for determining open-lung PEEP, the lowest PEEP that prevents lung collapse after a lung recruitment maneuver. Design: Prospective animal study. Setting: Department of Clinical Physiology, University of Uppsala, Sweden. Subjects: Eight lung-lavaged pigs. Interventions: Animals were ventilated using constant flow mode with VT of 6 ml/kg, respiratory rate of 30 bpm, inspiratory-to-expiratory ratio of 1 : 2, and FiO(2) of 1. Baseline measurements were performed at 6 cmH(2)O of PEEP. PEEP was increased in steps of 6 cmH(2)O from 6 to 24 cmH(2)O. Recruitment maneuver was achieved within 2 min at pressure levels of 60/30 cmH(2)O for Peak/PEEP. PEEP was decreased from 24 to 6 cmH(2)O in steps of 2 cmH(2)O and then to 0 cmH(2)O. Each PEEP step was maintained for 10 min. Measurements and results: Alveolar dead space (VDalv), the ratio of alveolar dead space to alveolar tidal volume (VDalv/VTalv), and the arterial to end-tidal PCO2 difference (Pa-ETCO2) showed a good correlation with PaO2, normally aerated areas, and non-aerated CT areas in all animals (minimum-maximum r(2) = 0.83-0.99; p < 0.01). Lung collapse (non-aerated tissue > 5%) started at 12 cmH(2)O PEEP; hence, open-lung PEEP was established at 14 cmH(2)O. The receiver operating characteristics curve demonstrated a high specificity and sensitivity of VDalv (0.89 and 0.90), VDalv/VTalv (0.82 and 1.00), and Pa-ETCO2 (0.93 and 0.95) for detecting lung collapse. Conclusions: Monitoring of dead space was useful for detecting lung collapse and for establishing open-lung PEEP after a recruitment maneuver.
Place, publisher, year, edition, pages
2006. Vol. 32, no 11, 1863-1871 p.
dead space, lung recruitment, SBT-CO2, atelectasis, oxygenation, PEEP
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-96744DOI: 10.1007/s00134-006-0371-7ISI: 000241453400030PubMedID: 17047925OAI: oai:DiVA.org:uu-96744DiVA: diva2:171422