An infant incubator is a see through container with armholes and a heater that keeps the internal space at a selected temperature between 34 to 37 degrees Centigrade. Infant incubator is used to keep unwell newborn or premature infants in controlled conditions of temperature, humidity, and oxygen levels, similar to what is obtainable in the mother’s womb. Doors are provided on the sides to allow access to the infant. It incorporates a low-power heater, a fan to circulate the air, and alarms for mains failure notification or overheating.
The air and surfaces of the internal space has a temperature limit of 39 degrees Centigrade. Most incubators have a thermistor attached to the baby while the less common ones make use of a heater controlled by an air probe. Temperature in old incubator units is rheostat controlled and as such, require manual adjustment as conditions change.
Newer units digitally display temperature via panel displays, with older units making use of analog metre, while the almost obsolete is incorporated with a thermometer. Mercury thermometers should not be found in an infant incubator.
Infant incubator, like other Intensive care unit (ICU) equipment fall into the category of class III medical equipment that require thorough cleaning and preemptive maintenance every 6 months (twice a year). It also requires day-to-day maintenance of door latches and seals.
Pre-use check involves:
- Electrical safety check
- Paint free interior
- Effective fanning system
- Maintenance of set temperature
- Correctly read dials
- High-temperature alarm; correct to function
Cleaning and Disinfection.
You should clean the incubator using soap and water, and thereafter rid it of any moisture to prevent bacteria growth. Special attention should be paid to corners which are to be dried thoroughly using absorbent paper.
Remove porous materials (filters, fabrics, beddings etc) from the incubator and place a bowl of formaldehyde solution (formalin <1% Methanol) in the incubator. Turn on the incubator, and leave it to heat with the fan circulating the air, for at least 90 minutes at a temperature >20 degrees Centigrade. Thereafter, replace formaldehyde solution with a bowl of ammonia solution and leave for another 90 minutes with the heater and fan switched on. This removes the undesirable smell of formalin.
Remove the ammonia solution, strip the machine down and clean with soap and water. If after cleaning, there is still some residual smell of formalin, leave the incubator running until all the smell has disappeared. Filters and fabrics should be disinfected by other means as formaldehyde is unsuitable for porous substances.
FAULTY ALARM: Incubator set in the manual mode of operation lacks a feedback (alarm) system as it is used to pre-heat the unit to warm up to a selected set point. Alarm settings for over and under temperatures in the incubator is set at a default temperature cutoff that prevents the incubator from heating below 36 degrees or above 39 degrees Centigrade. Failure would require calibration or replacement.
NOISY FAN: Noise level in the infant chamber should not exceed 65db, as it can cause long term hearing impairment in the infant. Heat is generated via a resistance coil below the baby while a fan pushes the heated air through vents in the bottom of the infant chamber. A noisy fan could result from rust in the bearings. It is corrected by lubrication on a regular basis or total replacement.
OBSTRUCTED FLOW PATH: Incubators possess inner wall in the infant chamber that directs the flow of the heated air around the infant thereby ensuring stable temperature and even distribution across the infant in all positions.These inner walls are held in place with plastic standoff posts and may loosen up with use. These standoff posts should be properly fastened in place.
HARZADOUS MERCURY: The mercury vapors are toxic to developing nervous systems and exposure can cause lasting damages in a neonate.The infant chamber and heater areas should be closely inspected and cleared of mercury spills from a broken thermometer. Note on mercury is hazard is discussed in this article.
CLOGGED FILTER: The fan also draws in room air, through a filter, which has to be cleaned or replaced on a regular basis against the backdrop of dust deposition. Replacement need is determined by the environment and hours used.
DRY RESERVOIR: To reduce the water loss of an infant in an incubator, relative humidity in the incubator is maintained between 60 and 90%. This is achieved by attaching a reservoir of water that the air moves over to increase the humidity in the infant chamber.
NEGATIVE LATCH: All the access doors (armholes), should have positive latches on them so the stay closed.The access doors in the hood make use of sleeves that closes around the clinicians arms as they work on the infant. All access doors and entry ports have protective covers that act as gaskets around them. They should be replaced when the material starts to flake off.