Current brands: advantages & disadvantages

 

1.                   Jostra Heater Cooler unit HCU 20-600

a)                   Supplies the heater-exchanger of the extracorporeal circulation &/or blanket with temperature controlled water

b)                  Cooling system: Compressor refrigeration

c)                   Both pressure & suction are used to circulate the water

d)                  Has facility for automatic temperature regulation

e)                   Infinite adjustment of temperatures

f)                    Easy to operate

g)                  Quiet

h)                  Only one tank to fill

i)                    High current draw especially when cooling)

i)                    Require correct current area

j)                    Easy to clean

k)                   Easy to maintain

 

 

2.                   Sarns Dual Cooler-Heater

a)                   Supplies the heater-exchanger of the extracorporeal circulation or blanket with temperature controlled water (only one outlet set)

b)                  Cooling system: ice slush reservoir

c)                   In cooling mode the water is diverted via the ice-water tank

d)                  Limited temperature settings

e)                   Economical

f)                    Excellent deep hypothermia function

g)                  Require ice supply

h)                  Too large in incremental adjustment of heating & cooling

 

 

3.                   Hemotherm (Cincinnati sub zero)

a)                   Two water reservoirs

i)                    Cool reservoir

ii)                   Heat reservoir

b)                  Two tanks to fill

c)                   Bulky

d)                  Hard to clean due to grilling at front

e)                   Quiet

f)                    Water flow indicator comes standard

g)                  Require two buttons to activate flow

 

 

Power requirements for heater-coolers

 

240V 50Hz

 

Jostra HCU 20

Sarns Dual

Independent current supply requirement

16 Amp

10 Amp

Heating capacity

2250 W (10A)

1500 W

Cooling capacity

2500 KJ (600 kcal/hr)

 

 

Have high current when cooling (compressors on) - require separate power outlet

 

Details, designs & mechanisms

 

 

Jostra HCU 20

Sarns Dual

Water flow & pressure

8 litres /min

4 psi

 

Reservoir volume

34 L of 3°C cold water; ensures quick cooling of patient

32 litres

Heating/Cooling range

3 - 41°C

Water in cold water tank is kept at a constant 3°C

Cooling rate is varied by altering the pump flow via the ice tank (1, 2, 3, 4); Heating is controlled by adjusting the temperature cut off of the heater (30, 38, 40, 42°C)

Heating/Cooling capacity

Cool down from 20°C to 2°C c. 50 minutes

 

Maximum circulation pressure

c 150 kPa

c 76 kPa

Flow capacity

35 L/min

25 L/min

Operating temperature controls & displays

In ‘patient’ operating mode, patient temperature can be used as a control; in this mode a temperature gradient can be adjusted to prevent water temperature from exceeding or falling below the patient’s temperature by greater than a preset value

Digital displays of set temperature & actual water temperature/cold water temperature/tank level

Output water temperature indicated on a dial thermometer located on front panel

Computer output (RS232)

Available

Non available

Outlets for water blankets

Two sets of outlets

Only one set of outlets

Construction materials

Copper spirals of heat exchanger

Stainless steel casing (easy to clean)

Covered in plastic; steel chassis

 

Safety control devices

 

 

Jostra HCU 20

Sarns Dual

Overpressure alarms

Max pressure c 150 kPa

audible alarm

 

Over temperature control & alarms

Safety mechanism limits the water temperature to 42°; also prevents overheating if operated accidentally without water

Shuts down to 35°C; will not reheat until water temp drops to 35°C

If temperature of the water in the heater manifold exceeds 42°C, the circulating pump & the heater are shut off & an overtemp light is illuminated; override button to continue circulating pump but not temperature

Resettable fuses

Located in front panel; 3 fuses: Heater; Compressor; pump

Glass fuses (main supply & control panel)

Pump circuit breaker; heater circuit breaker; both stop power to respective components if the respective circuit overloads; can be rest by pushing red button

Glass main fuse

Low water level

Front panel can give tank volume in litres

Have an overflow if tank is overfilled

Tank is filled to 32 litres

Audible low level & display

No alarm: do not use unless at least 10 cm of water in ice-water tank

Manual override controls

 

Override switch allows the circulating pump (but not heater)  to run during an overtemperature condition

 

Preventative maintenance

 

 

Jostra HCU 20

Sarns Dual

 

Jostra

 

Filling Tanks

Daily fill to 32 litres

Do Not use distilled water as will damage copper spirals of heat exchanger

 

Air intakes

Ensure that air can circulate unhindered to the condenser at the rear

 

Air condensator

Monthly clean with a brush

 

Bacterial control

Weekly  - monthly empty & refill

6 monthly swab of tank

Use chlorinated water; however excessive chlorine will cause corrosion

Daily test chlorine

Weekly clean with detergent & sanitise with chlorine

Descale

 

6 monthly

Maintenance Inspection

 

6 monthly by biomed etc

 

New O rings in couplings

6 monthly