Pressure damage in intact skin is difficult to detect, particularly in individuals with dark skin, because color changes and tissue blanching are masked by the skin's pigmentation. Tissue reflectance spectroscopy (TRS) may be able to detect the blanch response regardless of skin color by measuring the change in total hemoglobin (delta tHb) that occurs when pressure is applied to the skin. The objective of this dissertation was to examine the ability of TRS to detect the blanch response at sites at risk for pressure ulcer development in individuals with various levels of skin pigmentation. Three studies were conducted to address this objective. In Study 1, delta tHb was assessed at the heel and sacrum of light and dark-skinned healthy participants using a portable TRS system. Study 1 showed that a significant decrease (p less than 0.001) in tHb could be measured in both light and dark skinned-participants with good intra-rater reliability (ICC greater than or equal to 0.80) at the heel, but not at the sacrum. Study 2 was conducted to identify a reliable method of skin color description for use in subsequent studies of the spectroscopic blanch response. Two examiners (B and C) performed three skin color assessments at the volar forearm of ten healthy participants using Munsell color tile matching and colorimetry. Intra and inter-rater reliability was excellent for colorimetry (ICCs typically greater than or equal to 0.90). Reliability for Munsell color tile matching was highest for Munsell value within Examiner B (93% agreement, kappa 0.87-1.00), which was determined to be sufficiently high for use in subsequent studies. In Study 3, delta tHb was assessed at the heels of light, moderate, and dark-skinned elderly nursing home residents at risk for pressure ulcers. As in the pilot study, a significant decrease in tHb was observed in all skin color groups (p less than 0.05). Intra-rater reliability for delta tHb was moderate or greater (ICC greater than or equal to 0.61). In combination, the results of Study 1 and Study 3 demonstrated that a significant spectroscopic blanch response could be detected with moderate or greater intra-rater reliability at the heel regardless of age or pressure ulcer risk status
