Preclinical evidence of mitochondrial nicotinamide adenine dinucleotide as an effective alarm parameter under hypoxia.
Early detection of tissue hypoxia in the intensive care unit is essential for effective treatment. Reduced nicotinamide adenine dinucleotide (NADH) has been suggested to be the most sensitive indicator of tissue oxygenation at the mitochondrial level. However, no experimental evidence comparing the kinetics of changes in NADH and other physiological parameters has been provided. The aim of this study is to obtain the missing data in a systematic and reliable manner. We constructed four acute hypoxia models, including hypoxic hypoxia, hypemic hypoxia, circulatory hypoxia, and histogenous hypoxia, and measured NADH fluorescence, tissue reflectance, cerebral blood flow, respiration, and electrocardiography simultaneously from the induction of hypoxia until death. We found that NADH was not always the first onset parameter responding to hypoxia. The order of responses was mainly affected by the cause of hypoxia. However, NADH reached its alarm level earlier than the other monitored parameters, ranging from several seconds to >10  min. As such, we suggest that the NADH can be used as a hypoxia indicator, although the exact level that should be used must be further investigated. When the NADH alarm is detected, the body still has a chance to recover if appropriate and timely treatment is provided.
Huazhong University of Science and Technology, Department of Biomedical Engineering, MoE Key Laboratory for Biomedical Photonics, Wuhan 430074, ChinabWuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Wuhan 4300.
Hua
H
Shi
Huazhong University of Science and Technology, Department of Biomedical Engineering, MoE Key Laboratory for Biomedical Photonics, Wuhan 430074, ChinabWuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Wuhan 4300.
Nannan
N
Sun
Wuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Wuhan 430074, China.
Avraham
A
Mayevsky
Huazhong University of Science and Technology, Department of Biomedical Engineering, MoE Key Laboratory for Biomedical Photonics, Wuhan 430074, ChinabWuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Wuhan 4300.
Zhihong
Z
Zhang
Huazhong University of Science and Technology, Department of Biomedical Engineering, MoE Key Laboratory for Biomedical Photonics, Wuhan 430074, ChinabWuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Wuhan 4300.
Qingming
Q
Luo
D000818:Animals; D002540:Cerebral Cortex / Q000473:pathology; D002560:Cerebrovascular Circulation; D056902:Clinical Alarms; D003422:Critical Care; D004562:Electrocardiography; D006940:Hyperemia; D000860:Hypoxia; D007362:Intensive Care Units; D007700:Kinetics; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D008991:Monitoring, Physiologic / Q000379:methods*; D009243:NAD / Q000378:metabolism*; D010100:Oxygen / Q000737:chemistry; D010101:Oxygen Consumption; D051381:Rats; D017208:Rats, Wistar
D009243:NAD; D010100:Oxygen