The measurement of axillary moisture for the assessment of dehydration among older patients: A pilot study

PurposeDry axilla can sometimes be found among dehydrated older patients. In this study, we measured the axillary moisture and assessed it as possible marker for dehydration.MethodsTwenty-nine older patients admitted with acute medical conditions participated in this study. Dehydration was diagnosed by the calculated serum osmolality of greater than 295 mOsm/L. The moisture of axilla was measured by a skin moisture impedance meter which was applied at the center of axilla of patients.Results11 patients (7 males and 4 females) were diagnosed as dehydrated and 18 patients (10 males and 8 females) were diagnosed as non-dehydrated. The mean axillary moisture (33%) in the dehydrated group was significantly lower than that (42%) in the non-dehydrated group (p < 0.05). The axillary moisture ≥ 50% showed the sensitivity of 88%. The axillary moisture < 30% showed the specificity of 91%. Use of a single cutoff value of 40% moisture produced the sensitivity of 59% and the specificity of 9%. As for the physical signs, dry axilla had also moderate sensitivity and excellent specificity to detect dehydration.ConclusionsThe measurement of the axillary moisture could help assess dehydration. Dehydration could be ruled out when the axillary moisture ≥ 50%, while it could be ruled-in when the axillary moisture is < 30%.

► We measured the axillary moisture by the conductance device in older patients.
► The mean axillary moisture was low in the dehydrated group.
► The skin moisture was associated with physical diagnosis for dehydration.