Abstract
Our aim was to confirm earlier studies showing tcPO(2) to be higher under clothing made with polyethylene terephalate (PET) fabric containing ceramic particles (CEL) compared to standard PET fabric. In previous studies PET garments were donned first to avoid possible persistent effects from ceramic particles. This study randomized donning sequence to avoid bias. METHODS: Subjects were randomized to don either PET shirts first (PETF n=73) or CEL first (CELF n=80), switching garments after 90 minutes. Skin temperature (ST), arterial oxygen saturation (O(2)sat), and tcPO(2) were measured every 30 minutes. RESULTS: Baseline ST and O(2) sat were nearly identical in the two groups. Baseline tcPO(2) was modestly higher in the CELF group than with PETF: 66.4 ± 18.9 vs. 63.9 ± 18.8 mmHg (n.s). Independent of donning sequence, tcPO(2) measurements 90 minutes after wearing CEL were 6.7% higher than after 90 minutes wearing PET (p<0.0003). Sequence analysis found tcPO(2) in PETF subjects to gradually rise before and after switching garments, but tcPO(2) fell immediately after switching garments in CELF subjects. PETF baseline O(2)sat of 98.1 ± 1.3 increased insignificantly after 90 minutes, and then increased further to 98.6 ± 0.8 after wearing CEL ninety minutes (p=0.0001). CELF baseline O(2)sat of 97.9 ± 1.7 increased to 98.5 ± 1.1 90 minutes after donning CEL (p=0.0002) and fell to 98.3 ± 1.0 ninety minutes after switching to PET (p=0.0033). CONCLUSIONS: The ability of ceramic-embedded fabric to induce higher tcPO(2) measurements is not due to sequence bias.