Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8130881 | Ultrasound in Medicine & Biology | 2018 | 8 Pages |
Abstract
Pulmonary capillary hemorrhage (PCH) can be induced by diagnostic ultrasound-a potential safety issue. Anesthetized rats were intubated for intermittent positive-pressure ventilation (IPPV) with 0 end-expiratory pressure, +4âcm H2O end-expiratory pressure (PEEP) and â4âcm H2O end-expiratory pressure (NEEP). Rats were imaged at 7.6âMHz with a Philips HDI 5000 ultrasound machine. The output was low (mechanical index [MI] = 0.22) for aiming and then was raised for 5âmin in 20 different exposure groups with n = 8. Peak rarefactional pressure amplitudes were measured in water and de-rated for chest attenuation. The PCH areas were measured on the lung surface. At 2.2âMPa, PCH was 9.3 ± 6.6âmm2 for IPPV, 1.6 ± 3.2âmm2 for PEEP (pâ<0.001) and 26.8 ± 6.4âmm2 for NEEP (pâ<0.001). Thresholds were 1.3âMPa for IPPV, 2.1âMPa for PEEP and 1.0âMPa for NEEP. The small ventilator pressures subtracted or added to trans-capillary stress generated by diagnostic ultrasound pulses, virtually eliminating PCH for PEEP but enhancing PCH for NEEP.
Related Topics
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Authors
Douglas L. Miller, Zhihong Dong, Chunyan Dou, Krishnan Raghavendran,