Measurement of peripheral oxygen utilisation in neonates using near infrared spectroscopy: comparison between arterial and venous occlusion methods

Foot Pulse Oximeter Perfusion Index Correlates with Calf Muscle Perfusion Measured by Near-Infrared Spectroscopy in Healthy Neonates

“…To the best of our knowledge, this is the first time that foot PI, measured by pulse oximetry, is compared with parameters relating to the peripheral perfusion and oxygen consumption measurable by NIRS. [10][11][12]15,16,18,22 Only recent developments of pulse oximetry have enabled foot PI to be calculated. 2,3 Although the mechanisms underlying PI changes remain to be elucidated, local skin vasoconstriction appears to be the most likely reason for significantly lower PI readings in very sick patients.…”

“…Given the lack of other noninvasive methods, NIRS has been the only bedside clinical tool available in the last few years for evaluating muscle circulatory status in healthy and sick neonates and many significant clinical studies have been published. [8][9][10][11][12]16,18,22,25 NIRS was combined in our study with arterial/venous occlusion maneuvers to measure local muscle BF, VO 2 , and SvO 2 . 9,10,22 Using this NIRS approach, FOE proved to be a better indicator of the need for transfusion in anemia than hemoglobin concentration.…”

“…This would explain not only a BF change due to the arterial inflow, but also a BF redistribution from the capillaries to the skeletal muscles 26 according to the energy demands. Neonatal calf and forearm VO 2 were measured by NIRS on both arterial and venous occlusion, but Hassan et al 10 demonstrated that arterial occlusion produces more consistent results; they used arterial occlusion to investigate the effects of a change in global metabolic rate on peripheral oxygen consumption, 12 and the effect of limb cooling on peripheral and global oxygen consumption. 11 As for VO 2 We agree with his results because this method gave us a lower coefficient of variation than venous occlusion, as well as a lower VO 2 value (0.3 mM/100 ml/minute) than the 3.2 mM/100 ml/ minute obtained using venous occlusion.…”

“…The Hb flow was calculated, according to Wardle and Weindling, 8 NIRS and Arterial Occlusion to Calculate VO 2 The cuff was inflated rapidly on the thigh to 100 mmHg for 30 to 40 seconds to obtain an arterial occlusion; VO 2 was calculated from the rate at which O 2 Hb changes to HHb during the first 3 seconds ¼ R DO 2 Hb dt. 10,17 The interval between occlusions was set at 5 minutes to ensure a sufficient recovery period.…”

“…6 Near-infrared spectroscopy (NIRS) has been used largely in neonates for the noninvasive assessment of brain tissue oxygenation 7 and, less often, to evaluate limb oxygenation. [8][9][10][11][12] Considering that: (1) the spot measurement of BF and VO 2 by NIRS takes at least 20 minutes; and (2) the accuracy of NIRS changes is limited because path length and its changes are not known, 7 the foot PI measured by pulse oximetry seems to be more feasible than indirect NIRS methods for monitoring peripheral perfusion in the neonatal intensive care unit. We hypothesized that foot PI could also adequately evaluate limb perfusion.…”