Measurements of alveolar pO2 using 19F-MRI in partial liquid ventilation.
OBJECTIVE
Partial liquid ventilation using Perfluorcarbon (PFC) is an innovative treatment of acute respiratory distress syndrome. However, the underlying mechanisms are not totally clear. The aim was to investigate the distribution of oxygen partial pressure within the PFC-filled lung (ppO2).


METHODS
Nine pigs underwent partial liquid ventilation, receiving 20 mL PFC/kg bodyweight (bw). Measurements were obtained by a chemical shift selective TurboFLASH sequence at different axial lung levels. ppO2 was calculated from 19F-MRI by nonlinear curve T1-fitting technique after noise correction.


RESULTS
Quantification and distribution of ppO2 was performed successfully. A narrow relationship of the inspiratory O2 fraction and ppO2, as well as a significant ventral-to-dorsal gradient of ppO2 (ventral:dependent lung = 1.9:1) were detected in all subjects and slice positions.


CONCLUSIONS
In vivo measurement of local ppO2 gains new and clinical important insights into the physiology of PLV. The previously unknown ppO2 gradient within PFC fits to distribution of perfusion. Dependent lung regions appear to have limited access to O2 from central airways.
D000818:Animals; D005465:Fluorocarbon Polymers; D021061:Liquid Ventilation / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000032:analysis*; D010313:Partial Pressure; D011650:Pulmonary Alveoli / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000503:physiopathology* / Q000628:therapy*
D005465:Fluorocarbon Polymers; D010100:Oxygen