Understanding Sweat Moisture Vapour Transmission Rates (MVTR) & Patient Care
The prevention of moisture lesions and patient care
The human body is largely made up of water, making it the largest component in the body. At birth it constitutes up to 75 % of the body weight, through age this decreases to 70% in adulthood and 50% in old age (Nutritional Needs in Hot Environments: Applications for Military Personnel in Field Operation, Institute of Medicine 1993, Carl V.Gislfi).
Through food, drink, and oxidation the average adult intake of water is 2400 ml per day. The expulsion or output of fluids is the same value with 1400ml output through urine, 900ml through lungs and skin and 100ml faeces per day (SOURCE: Gisolfi (1986), used with permission. Data modified from Muntwyler (1968).
We have three different types of sweat glands, the main one being the Eccrine sweat gland that can be found in larger numbers across the whole body generating the highest volume of sweat excretion. The apocrine and apoeccrine glands are limited to specific areas of the body and produce far fewer sweat secretions but can impact the way in which it collects on the skin (Physiology of sweat gland function: The roles of sweating and sweat composition in human health, Lindsay B. Baker, www.ncbi.nlm.nih.gov/pmc/articles/PMC6773238/)
There are several factors that can affect sweat production/output:
Weather and the temperature of our environment impacts the body temperature. If body temperature increases due to either environment or physical, the body produces more sweat.
Naturally, the sweating threshold increases during the Circadian Rhythm between 12-00 - 1600hr. Body mass also has a big impact on sweat secretions as those with larger body mass index have an increased metabolic heat production (Lindsay B. Baker).
Medical conditions and medications can both increase and decrease sweat output and evaporation rates. Both can have negative impact especially if mobility is affected (bed bound or prolonged time in bed).
Conditions such as Cystic Fibrosis, Adison’s Disease, Hyperhidrosis can all increase sweating (Lindsay B. Baker).
When sleeping some of the more serious causes of “Night Sweats” include: -
(Why Do We Sweat While Sleeping? Brandon Peters, MD, 2021)
- Sleep apnoea
- Autoimmune disorders
- Some cancers, especially Hodgkin’s lymphoma cause excessive sweating.
The thermoregulation rate is important part of sweating as the rate of evaporation is crucial for temperature control.
Moisture lesions or MASD is where prolonged exposure to various moisture sources such as sweat, urine (5) causes inflammation and erosion of the skin. There are 4 types of MASD (Differentiating between pressure ulcers and moisture lesions – wound Essentials 2012 Vol 2).
Benefits of having a good level of Moisture Vapour Transmission Rate can help limit the risk of moisture lesions thereby limiting the confusion between pressure related ulcers and moisture lesion which can be difficult to determine and can impact the patient care plans.
Simple things like the material the mattress cover is made of can increase the Moisture Vapour Transmission rate and thus decreasing the potential for moisture lesions. Here at Apex, we continually research and work with industry professionals on the design of our products to maximise and improve patient care.
The Verso mattress cover has been expertly designed and engineered. using high quality materials for better clinical outcomes and long-term use.
The Verso’s multi-functional 4-way stretch PU coated polyester top cover has high vapour permeability, yet high water resistance with an impressive MVTR of 2315 g/24h-m2 (ASTM E96) in its class.
- Nutritional Needs in Hot Environments: Applications for Military Personnel in Field Operations. - Institute of Medicine (US) Committee on Military Nutrition Research; Marriott BM, editor. Washington (DC): National Academies Press (US); 1993.- Carl V. Gisolfi
- Very well Health. Why Do We Sweat While Sleeping? By Brandon Peters, MD Medically reviewed by Sanja Jelic, MD Updated on June 02, 2021
- Physiology of sweat gland function: The roles of sweating and sweat composition in human health, Lindsay B. Baker
- Differentiating between pressure ulcers and moisture lesions – wound Essentials 2012 Vol 2