The purpose of this study is to understand how changes to breathing patterns in the chest affect blood flow to the heart from the inferior vena cava in the abdomen. Ultrasound of the upper abdomen will be used to visualize changes in breathing patterns in the chest and blood flow in the abdomen.
In recent practice, point-of-care ultrasound has been used to assess the size and respiratory variation of the inferior vena cava as a marker for volume status and fluid responsiveness. Little investigation has occurred regarding the mechanism of observed respiratory variation. Anesthetic plans for surgery (e.g. shoulder replacement) frequently employ interscalene injections to target and block the brachial plexus, which (on the same side) results in phrenic nerve palsy and paralysis of the diaphragm. The goal of this study is to examine the relationship between diaphragmatic function and variation in IVC diameter. Specifically, the investigators will evaluate and compare the size and variability of the inferior vena cava by point-of-care ultrasound before and after brachial plexus block.
Study Type
OBSERVATIONAL
Analgesic nerve block as part of routine care with pre- and post-block ultrasonographic imaging of the diaphragm and inferior vena cava
UCSD Medical Center
La Jolla, California, United States
Ipsilateral hemiparesis
Detectable paralysis of the ipsilateral hemidiaphragm by point of care ultrasound
Time frame: Within 30 minutes post-block
IVC Collapsibility Index Change
Measured IVC diameter and collapsibility by point of care ultrasound
Time frame: Within 30 minutes post-block
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