Sweat chloride concentration in patients with heat stroke

ABSTRACT

The effect of hyperpyrexia on sweat gland function in heat stroke [HS] has been poorly studied. The aim of this study was to assess changes in sweat chloride concentration before and after recovery from heat stroke. Sweat chloride concentration in response to pilocarpine stimulation was measured in 10 HS patients on admission and after 12 h and was compared with that of 7 heat exhaustion [HE] and 10 heat stress patients. The mean age of HS patients was 51.1 +/- 8.9 years. Their mean rectal temperature was 42.9 +/- 0.6 [degree]C, cooling time was 96 +/- 12 min, APACHE II score was 23.5 +/- 6.9, and serum lactate concentration was 5.2 +/- 2.1 mmol/L. The mean sweat chloride concentration was significantly lower among HS patients [5.3 +/- 0.6 mmol/L] compared with HE [20.0 +/- 1.5 mmol/L, p< 0.0001] and heat stress patients [27 +/- 3.2 mmol/L, p< 0.0001]. The mean sweat chloride concentration at 12 h among 8 HS patients who survived increased to 17.9 +/- 6.6 mmol/L, whereas in 2 HS patients who died, the sweat chloride concentration remained unchanged [p<0.0001]. Sweat chloride concentration in HS was markedly reduced compared to HE and heat stress. However, in HS patients who survived, sweat chloride concentration recovered 12 h after treatment.