BACKGROUND: Cerebral oximetry is a noninvasive bedside technology using near-infrared light to monitor cerebral oxygen saturation (Sco2) in an uncertain mixture of arteries, capillaries, and veins. The present study used frequency domain near-infrared spectroscopy to determine the ratio of arterial and venous blood monitored by cerebral oximetry during normoxia, hypoxia, and hypocapnia. METHODS: Twenty anesthetized children aged < 8 yr with congenital heart disease of varying arterial oxygen saturation (Sao2) were studied during cardiac catheterization. Sco2, Sao2, and jugular bulb oxygen saturation (Sjo2) were measured by frequency domain near-infrared spectroscopy and blood oximetry at normocapnia room air, normocapnia 100% inspired O2, and hypocapnia room air. RESULTS: Among subject conditions, Sao2 ranged from 68% to 100%, Sjo2 from 27% to 96%, and Sco2 from 29% to 92%. Sco2 was significantly related to Sao2 (y = 0. 85 x -17, r = 0.47), Sjo2 (y = 0.77 x +13, r = 0.70), and the combination (Sco2 = 0.46 Sao2 + 0.56 Sjo2 - 17, R = 0.71). The arterial and venous contribution to cerebral oximetry was 16 +/- 21% and 84 +/- 21%, respectively (where Sco2 = alpha Sao2 + beta Sjo2 with alpha and beta being arterial and venous contributions). The contribution was similar among conditions but differed significantly among subjects (range, approximately 40:60 to approximately 0:100, arterial:venous). CONCLUSIONS: Cerebral oximetry monitors an arterial/venous ratio of 16:84, similar in normoxia, hypoxia, and hypocapnia. Because of biologic variation in cerebral arterial/venous ratios, use of a fixed ratio is not a good method to validate the technology.
BACKGROUND: Cerebral oximetry is a noninvasive bedside technology using near-infrared light to monitor cerebral oxygen saturation (Sco2) in an uncertain mixture of arteries, capillaries, and veins. The present study used frequency domain near-infrared spectroscopy to determine the ratio of arterial and venous blood monitored by cerebral oximetry during normoxia, hypoxia, and hypocapnia. METHODS: Twenty anesthetized children aged < 8 yr with congenital heart disease of varying arterial oxygen saturation (Sao2) were studied during cardiac catheterization. Sco2, Sao2, and jugular bulb oxygen saturation (Sjo2) were measured by frequency domain near-infrared spectroscopy and blood oximetry at normocapnia room air, normocapnia 100% inspired O2, and hypocapnia room air. RESULTS: Among subject conditions, Sao2 ranged from 68% to 100%, Sjo2 from 27% to 96%, and Sco2 from 29% to 92%. Sco2 was significantly related to Sao2 (y = 0. 85 x -17, r = 0.47), Sjo2 (y = 0.77 x +13, r = 0.70), and the combination (Sco2 = 0.46 Sao2 + 0.56 Sjo2 - 17, R = 0.71). The arterial and venous contribution to cerebral oximetry was 16 +/- 21% and 84 +/- 21%, respectively (where Sco2 = alpha Sao2 + beta Sjo2 with alpha and beta being arterial and venous contributions). The contribution was similar among conditions but differed significantly among subjects (range, approximately 40:60 to approximately 0:100, arterial:venous). CONCLUSIONS: Cerebral oximetry monitors an arterial/venous ratio of 16:84, similar in normoxia, hypoxia, and hypocapnia. Because of biologic variation in cerebral arterial/venous ratios, use of a fixed ratio is not a good method to validate the technology.
Authors: Maria Angela Franceschini; David A Boas; Anna Zourabian; Solomon G Diamond; Shalini Nadgir; David W Lin; John B Moore; Sergio Fantini Journal: J Appl Physiol (1985) Date: 2002-01
Authors: Turgut Durduran; Chao Zhou; Erin M Buckley; Meeri N Kim; Guoqiang Yu; Regine Choe; J William Gaynor; Thomas L Spray; Suzanne M Durning; Stefanie E Mason; Lisa M Montenegro; Susan C Nicolson; Robert A Zimmerman; Mary E Putt; Jiongjiong Wang; Joel H Greenberg; John A Detre; Arjun G Yodh; Daniel J Licht Journal: J Biomed Opt Date: 2010 May-Jun Impact factor: 3.170
Authors: David R Busch; Ramani Balu; Wesley B Baker; Wensheng Guo; Lian He; Mamadou Diop; Daniel Milej; Venkaiah Kavuri; Olivia Amendolia; Keith St Lawrence; Arjun G Yodh; W Andrew Kofke Journal: Neurocrit Care Date: 2019-02 Impact factor: 3.210
Authors: Thomas Alderliesten; Laura Dix; Wim Baerts; Alexander Caicedo; Sabine van Huffel; Gunnar Naulaers; Floris Groenendaal; Frank van Bel; Petra Lemmers Journal: Pediatr Res Date: 2015-09-21 Impact factor: 3.756
Authors: Victoria A McCredie; Simone Piva; Marlene Santos; Wei Xiong; Airton Leonardo de Oliveira Manoel; Andrea Rigamonti; Gregory M T Hare; Martin G Chapman; Andrew J Baker Journal: Neurocrit Care Date: 2017-04 Impact factor: 3.210