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Redistribution of pulmonary ventilation after lung surgery detected with electrical impedance tomography
Author(s) -
Lehmann Martin,
Oehler Beatrice,
Zuber Jonas,
Malzahn Uwe,
Walles Thorsten,
Muellenbach Ralf M.,
Roewer Norbert,
Kredel Markus
Publication year - 2020
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/aas.13525
Subject(s) - medicine , perioperative , vital capacity , ventilation (architecture) , electrical impedance tomography , spirometry , anesthesia , prospective cohort study , quartile , surgery , pulmonary surgical procedures , lung , nuclear medicine , radiology , tomography , confidence interval , lung function , mechanical engineering , asthma , diffusing capacity , engineering
Background Regional ventilation of the lung can be visualized by pulmonary electrical impedance tomography (EIT). The aim of this study was to examine the post‐operative redistribution of regional ventilation after lung surgery dependent on the side of surgery and its association with forced vital capacity. Methods In this prospective, observational cohort study 13 patients undergoing right and 13 patients undergoing left‐sided open or video‐thoracoscopic procedures have been investigated. Pre‐operative measurements with EIT and spirometry were compared with data obtained 3 days post‐operation. The center of ventilation (COV) within a 32 × 32 pixel matrix was calculated from EIT data. The transverse axis coordinate of COV, COVx (left/right), was modified to COVx′ (ipsilateral/contralateral). Thus, COVx′ shows a negative change if ventilation shifts contralateral independent of the side of surgery. This enabled testing with two‐way ANOVA for repeated measurements (side, time). Results The perioperative shift of COVx′ was dependent on the side of surgery ( P = .007). Ventilation shifted away from the side of surgery after the right‐sided surgery (COVx′‐1.97 pixel matrix points, P < .001), but not after the left‐sided surgery (COVx′‐0.61, P = .425). The forced vital capacity (%predicted) decreased from 94 (83‐109)% (median [quartiles]; [left‐sided]) and 89 (80‐97)% (right‐sided surgery) to 61 (59‐66)% and 62 (40‐72)% ( P < .05), respectively. The perioperative changes in forced vital capacity (%predicted) were weakly associated with the shift of COVx′. Conclusion Only after right‐sided lung surgery, EIT showed reduced ventilation on the side of surgery while vital capacity was markedly reduced in both groups.