Headahes, sore eyes and throat, nasal stuffiness, lethargy, skin complaints and increased suscepti-bility to colds and coughs are all symptoms of a dry atmosphere. Dry air will suck moisture from all possi-ble sources in the room including mucose membranes in the nose and throat, which are design to protect us from infection. Moisture will also be drawn any body tissue exposed during operations.
This can cause premature drying and promote the formation of a scab from coagulated blood.
Perhaps more importantly in theatre is the effect of electrostatic shocks which build up below 40%rH. The uncomfortable, surprising jolts caused by a sudden 'static discharge can have potentially damaging and dangerous effects on surgery, and consideration must also be given to the prevention of electrostatic sparks in relation to flammable anaesthetic gases. In fact there are very few areas in hospital that do not benefit from humidification.
Hospital Humidity Issues
By maintaining optimum humidity of between 50-60%rH, drying of body tissue is prevented and static charge build-up eliminated.
The humidity levels in maternity and obstetric departments should always be maintained as babies are particularly sensitive to a dry atmosphere. Also, low relative humidity can severely exacerbate the condition of patients with respiratory problems.
Moisture can be introduced to a hospital atmoshere via the builing's air handling system by either releasing a fine mist of cold water or steam into the air conditioning ductwork. Alternatively direct air systems can be used where humidity is introduced directly to a room on a more local level.
Steam is a very popular solution in hospitals as it ensures the moisture being introduced is 100% safe and also due to the fact that there is often a ready supply of steam being used for sterilising purposes.
Although electrode boiler steam humidifiers are a popular solution to hospital humidification, the installation of more cost effective resistive steam humidifiers can pay for itself within a few years.