AGE AND HYPOHYDRATION INDEPENDENTLY INFLUENCE THE PERIPHERAL VASCULAR RESPONSE TO HEAT STRESS

Seven young (Y, 22-28 yr) and seven middle-aged (MA, 49-60 yr) normotensive men of similar body size, fatness, and maximal oxygen uptake (VO2max) were exposed to a heat challenge in an environmental chamber (48 degrees C, 15% relative humidity). Tests were performed in two hydration states: hydrated (H, 25 ml water/kg body wt 1 h [...]

By |2013-01-31T18:34:05+00:00enero 31st, 2013|Age and the elderly, Scientific papers|0 Comments

HEAT STRESS IMPAIRMENT OF MENTAL PERFORMANCE: A REVISION OF TOLERANCE LIMITS

A time-related, heat stress tolerance curve for unimpaired mental performance was constructed by Wing from a summary of 15 studies. The tolerance limits, more properly described as the lower limits for heat impaired mental performance, were subsequently adopted by the National Institute for Occupational Safety and Health as the recommended standard of tolerance times for [...]

By |2013-01-31T18:34:05+00:00enero 31st, 2013|Mental performance, Scientific papers|0 Comments

INGESTION OF COLD FLUIDS: RELATED TO ONSET OF ARRHYTHMIAS?

Although the results of this study provide too limited a database for establishing definitive guidelines for practice, they underscore the need for critical care nurses to focus observations on patients' responses to iced fluid restriction. It is important to determine whether and to what extent limiting ingestion of iced fluids induces patient stress, a factor [...]

EFFECT OF SALT INTAKE ON RENAL EXCRETION OF WATER IN HUMANS

Two studies were performed to determine the quantitative relationship between salt intake and urinary volume (U(v)) in humans. In study 1, 104 untreated hypertensives were studied on the fifth day of a high- and a low-salt diet. The 24-hour U(v) was 2.2 L (urinary sodium [U(Na)] 277 mmol) on the high-salt diet and decreased to [...]

EFFECTS OF FLUID, ELECTROLYTE AND SUBSTRATE INGESTION ON ENDURANCE CAPACITY

The availability of carbohydrate (CHO) as a substrate for the exercising muscles is known to be a limiting factor in the performance of prolonged cycle exercise, and provision of exogenous CHO in the form of glucose can increase endurance capacity. The present study examined the effects of ingestion of fluids and of CHO in different [...]

AGE-RELATED FAILURE OF VOLUME-PRESSURE-MEDIATED VASOPRESSIN RELEASE

Osmoreceptor sensitivity, as estimated by the plasma vasopressin (AVP) response to hypertonic saline infusion, increases with age. We studied volume-pressure sensitivity, as estimated by the plasma AVP response to orthostasis, in healthy young (19-31 yr old; n = 12) and old (62-80 yr old; n = 15) subjects. After remaining recumbent overnight (minimum of 8 [...]

By |2013-01-31T18:33:42+00:00enero 31st, 2013|Age and the elderly, Scientific papers|0 Comments