Figure 1.
Effect of acute bilateral jugular vein compression on NIR-T/BSS variables during BOPT: cc-TQ is “cut” by the narrowing SAS.
Sharp edges of the cc-TQ waves are visible at the distant sensor (DS) and cc-TQ (enhanced tracings). cc-TQ – cardiac component of transillumination quotient (pial artery pulsation); µW/cm2 – microwatt/centimetre2.
Figure 2.
Effect of acute bilateral jugular vein compression on NIR-T/BSS variables in the initial position.
1 – sas-TQ, 2 – cc-TQ, 3 – enhanced tracing of the distant sensor (DS) signal (absence of the “cutting” effect and absent sharp edges), 4 – enhanced tracing of cc-TQ (absence of the “cutting” effect and absent sharp edges). sas-TQ – the subarachnoid component of the transillumination quotient (the subarachnoid width); cc-TQ – cardiac component of transillumination quotient (pial artery pulsation); µW/cm2 – microwatt/centimetre2.
Table 1.
Effects of acute bilateral jugular vein compression on sas-TQ, cc-TQ, CBFV, SAP, DAP, PP and HR during the BOPT test (BOPT – JVO; n = 10). Mean values and Standard Deviations (SD) are provided.
Table 2.
Effects of acute bilateral jugular vein compression on sas-TQ, cc-TQ, CBFV, SAP, DAP, PP and HR in initial position (Initial – JVO; n = 22).
Figure 3.
Linear correlation analysis of cc-TQ and PP change during bilateral jugular vein compression in initial position versus baseline.
All values of cc-TQ and PP obtained from 22 volunteers were included in the analysis of linear correlation (Spearman r = −0.74, p<0.001). cc-TQ – cardiac component of transillumination quotient (pial artery pulsation); PP – pulse pressure; mmHg – millimetres of mercury.