Surgical slush machines, explained by someone who builds them.
How they work, what to check before you buy, how to keep one running, and how to get a quote through your hospital’s purchasing contract.
How a surgical slush machine works
It’s a refrigeration system built around one idea: the sterile saline never touches the machine. A single-use drape lines the basin and becomes the sterile container, and the machine chills it from the outside.
- A
Stainless steel cabinet
Houses the refrigeration system, controls and stir drive. Stainless holds up to repeated wipe-downs between cases.
- B
Stainless slush basin
The cold bowl. Its wall is chilled well below the freezing point of saline so ice forms on the drape pressed against it.
- C
Evaporator
Refrigerant tubing wrapped around and bonded to the basin. As refrigerant boils off inside it, it pulls heat out of the steel.
- D
Condensing unit
Compressor, condenser coil and fan in the base. It dumps that heat into the room, which is why it needs clear airflow and a clean coil.
- E
Sterile drape
Transparent, liquid-proof and single use. It drapes over the top, conforms to each basin and hangs down the sides of the cabinet.
- F
Drape disc
A rigid disc bonded under the drape at the bottom of the basin. It’s the part the stir mechanism pushes against.
- G
Auto-stir
Drives the disc up and down. That flexes the drape so frozen saline breaks off the walls and drops into the center as slush, with no hand scraping.
- H
Warming basin
A second basin with a heater underneath for warm sterile fluid. One drape can cover the slush and warming basins together.
- Drape the machineThe sterile drape is seated in the basin with the disc centered on the stir.
- Add sterile salinePoured into the draped basin by the sterile team.
- Freeze on the wallThe evaporator chills the basin and ice forms on the drape.
- Stir breaks it freeThe disc moves up and down and ice falls off the walls.
- Slush is readyIt collects in the center for use on the sterile field.
Surgical slush is used in procedures that call for topical cooling of tissue or organs, such as cardiac and transplant surgery. Clinical use always follows your surgeons’ protocols and the manufacturer’s instructions for use.
What to check before you buy
The machine is a one-time purchase. The drapes are a cost on every case. Look at both before you compare prices.
Ask every supplier for the cost of drapes per case and whether they’re covered on your GPO contract. Over the life of the machine, drapes often add up to more than the machine itself.
- Basin layoutSlush only, slush plus warmer, or two slush basins. Match it to how your rooms actually run.
- Drape cost and supplyPrice per drape, who makes it, lead times, and whether it fits only this model.
- Auto-stir or manualAuto-stir saves the scrub team from scraping ice and gives more consistent slush.
- Footprint and mobilityCabinet size, locking casters, and cord length for your OR layout.
- ElectricalVoltage, amperage and plug type from the spec sheet, checked against your OR outlets.
- Service and partsWho repairs it, how fast, whether your biomed team can get parts and a service manual.
- Contract coverageWhether it’s on your GPO agreement or needs a local contract or value analysis review.
Care and troubleshooting
At heart it’s a small refrigeration system, and most problems are the same ones any refrigeration tech would recognize. These are common causes, not a repair manual.
Slush is slow to form or won’t form
Common causes
- Dirty or dusty condenser coil
- Vents blocked against a wall or cart
- Hot room or unit started late
- Refrigerant or compressor problem
What to do
- Give the cabinet clearance on all vented sides
- Have biomed clean the condenser coil
- Call qualified service for anything inside the sealed system
Ice builds up on the walls but doesn’t break free
Common causes
- Drape disc not centered on the stir
- Auto-stir switched off or not running
- Wrong drape for the model
What to do
- Check the drape is seated per the instructions for use
- Confirm the stir control is on
- If it still won’t move, take the unit out of service
Unit runs nonstop and the cabinet feels hot
Common causes
- Condenser fan not turning
- Clogged condenser coil
What to do
- Tag it and send it to biomed
- Don’t keep running a unit that’s overheating
Warming basin won’t heat or runs too hot
Common causes
- Temperature control or sensor fault
- Heater element failure
What to do
- Remove from service right away
- Have the temperature verified before it goes back to an OR
Drapes tear or leak
Common causes
- Sharp instruments dropped in the basin
- Disc not seated, so the drape is stressed
- Damaged or expired packs
What to do
- Replace the drape and follow your sterility policy
- Inspect packs before opening
Routine care
- Clean and disinfect the cabinet and basins between cases per your hospital policy.
- Clean the condenser coil on the schedule in the manufacturer’s manual.
- Check casters, cord and plug for damage.
- Verify cooling and warming performance during preventive maintenance.
Always follow the manufacturer’s instructions for use and your biomedical engineering department. Electrical and sealed-system repairs belong to qualified, authorized service technicians.
How hospitals buy this equipment
Most US hospitals don’t buy capital equipment off a website. They buy through a group purchasing organization (GPO) that negotiates contracts for its member hospitals. Three GPOs serve as the primary purchasing group for more than 80% of US hospitals.
Some large integrated systems, such as Kaiser Permanente, run their own sourcing. If you don’t know which contract your facility uses, your supply chain or materials management team will. Tell us in the quote form and we’ll factor it into who quotes you.
Source: JAMA Health Forum analysis of 2024 hospital GPO affiliations. GPO names are trademarks of their owners; this site is not affiliated with any GPO.
Common questions
- Is the slush drape reusable?
- No. Slush and warmer drapes are supplied sterile, used for one procedure, then discarded.
- Can one machine make slush and warm fluid?
- Yes. Multi-basin machines pair a refrigerated slush basin with a heated basin, and one drape can cover both.
- What goes in the basin?
- Sterile saline, poured into the draped basin by the sterile team.
- How long does it take to make slush?
- It depends on the model, the volume, and the room temperature. Ask for the time-to-first-slush figure on the spec sheet.
- Does it need a special outlet?
- Check the electrical rating on the spec sheet against your OR outlets before it’s delivered.
- Are you the manufacturer?
- No. This is an independent guide. Quote requests are passed to the manufacturer or authorized supplier best placed to answer them.
Request a quote or a demo
Tell us about your facility and what you need. Your request goes to a manufacturer or authorized supplier who can quote it.