Near infrared spectroscopy (NIRS) during papaverine therapy and balloon occlusion angiography: case reports

NIRS allows non-invasive measurements of relative blood volume and oxygen saturation in various tissues. One of its most important applications is in neurosurgery and neurointensive care, monitoring changes in perfusion and oxygen utilization in the brain. The following report describes two separate clinical cases: one during progressive intraarterial papaverine therapy in cerebral vasospasm, and the other during balloon occlusion angiography. A 30-mW variable gain, dual wavelength (769 nm, and 850 nm) NIRS instrument with a 5 mm² photon detector was used. The NIRS probe was positioned on the ipsilateral temporal and frontal regions for papaverine therapy and balloon occlusion, respectively. Changes in tissue oxygen saturation (DESAT) and blood volume (BV) were acquired continuously during progressive injection of intraarterial papaverine, as well as during 20 minutes of balloon occlusion. During papaverine therapy there were systematic statistically significant decreases in DESAT (p<0.001) for all incremental doses of papaverine; as well as between pre-occlusion (baseline), at 10 min and 20 min of occlusion, and after release of occlusion: (p=<.0001). BV changes where significant between baseline and 20 min of occlusion and between 10 and 20 min of occlusion