OT Linen Par Levels: How Much Theatre Linen Do You Need?

The par level for theatre linen is the total stock of each item you need so theatres never run short while the rest is being laundered, inspected and sterilised. The usual way to estimate it is to take your daily use of each item, multiply by the number of days one full reprocessing loop takes, then add allowances for peaks, losses and items retired at inspection. The result is a starting point that you then check against real usage.

This post walks through the calculation for reusable OT gowns, drapes and covers, with a worked example you can adapt.

Why theatre linen needs its own par levels

Ward linen par levels are usually expressed per bed. Theatre linen is different:

• Usage depends on the number and type of cases, not beds.
• Different procedures use different packs, so demand varies item by item.
• Items go through sterilisation as well as laundering, which lengthens the loop.
• A missing pack can delay or cancel a case, so the cost of running short is high.

For ward linen, see our separate guide to hospital linen par levels.

Step 1: Work out daily use per item

Start with your theatre activity, not with a rule of thumb.

1. List the procedure packs you use, for example general, laparotomy, caesarean, orthopaedic, minor.
2. For each pack, list the reusable items it contains and how many of each.
3. Take the average number of cases per day for each pack type, from your theatre system or logbooks.
4. Multiply to get daily use for each item, then add items used outside packs, such as extra gowns and towels.

Do this separately for gowns by size, because a shortage of one size is a shortage in practice, even if other sizes are plentiful.

Step 2: Measure the loop time

The loop time is how many days pass between an item being used and it being back on the shelf, ready to issue. It includes:

• Collection from theatre and transport to the laundry
• Waiting time before washing
• Washing, drying and finishing
• Transport back, inspection, folding and packing
• Sterilisation and any release or cooling time
• Weekends, public holidays and any days the laundry or CSSD does not run

Measure it, do not assume it. Track a sample of items through the loop for a couple of weeks and take the longer typical figure rather than the best case. Our guide to the reusable OT linen reprocessing cycle describes each stage.

Step 3: Calculate the base par

The base par covers everything in the loop at once:

Base par = daily use x loop days

Many sites add one more day's worth on the shelf as working stock, so items are always available at the start of a list:

Base par = daily use x (loop days + 1)

Step 4: Add allowances

The base par assumes every item comes back on time and in good condition. In practice you need allowances for:

Allowance	Why	How to estimate
Peak activity	Busier days, extra lists, emergency cases	Compare the busiest typical day with the average
Losses	Items that go out with waste or are not returned	From stock counts or tracking data
Inspection rejects	Items retired or sent to repair	From inspection records
Re-wash	Items sent back through the wash	From laundry or inspection records
Laundry delays	Breakdowns, holidays, transport issues	Based on past disruptions

You can add these as a percentage on top of the base par, or as a fixed number of extra days of stock. The right figure depends on your site's history; new facilities with no history usually start higher and adjust down once real data is available.

A worked example

The figures below are invented for illustration only. Replace them with your own.

Suppose a theatre suite uses an average of 40 surgeon gowns in size L per day, and the measured loop is three days including sterilisation.

1. Base par = 40 x (3 + 1) = 160 gowns
2. Allowance for peaks, losses, rejects and delays, agreed locally at, say, 25% = 40 gowns
3. Total par for size L = 200 gowns

Repeat this for each size and each item: drapes, Mayo and trolley covers, hand towels and wrapping cloths. Items used in fewer packs will have smaller pars, but even rarely used drapes need enough for the loop plus a reserve, or a single delay can leave a list without them.

Special cases

Emergency and out-of-hours packs

Emergency packs, such as caesarean or trauma packs, need to be available at any hour, regardless of the laundry's working days. Set a minimum number that must always be ready, separate from the calculated par.

Low-use specialist drapes

For drapes used only a few times a month, the formula may give a very small number. Set a floor based on the worst-case gap in the loop, so you always have at least one or two complete sets ready.

New theatres

New facilities have no usage history. Base the first estimate on planned activity and similar theatres, order the opening stock, and plan a review after the first few months. Our guide to OT linen for a new hospital covers opening stock planning.

Several theatres or sites

When one laundry or CSSD serves several theatres or sites, decide whether stock is pooled or held separately for each location. Pooled stock needs less linen overall, because peaks in one theatre are covered by quieter days in another, but it depends on reliable transport and clear marking. Separate stock is easier to manage locally but needs a higher total par. Whichever you choose, mark linen so it returns to the right place.

Keeping par levels accurate

A par level is only correct for as long as activity and the loop stay the same. Review it when:

• Theatre activity changes, such as new lists, new surgeons or new services
• The laundry provider, process or turnaround changes
• Inspection rejects or losses rise
• Items are replaced with a new design or size range

Regular stock counts, compared against the par, show whether stock is leaking out of the loop. If counts keep falling below par despite steady ordering, losses or early retirement need attention, not just more stock.

Ordering against par

Once par levels are set, use them to plan orders:

1. Compare current stock (in use, in the loop and on the shelf) with par for each item.
2. Add the items expected to reach their reuse limit before the next order arrives.
3. Order the difference, allowing for production and shipping time.

Because reusable OT linen is usually made to order and shipped, leave enough lead time that you are not forced into emergency purchases of different items that do not match your existing stock.

Checklist

• Daily use calculated per item and per gown size, from real activity
• Loop time measured, including weekends and holidays
• Base par calculated with working stock
• Allowances agreed for peaks, losses, rejects and delays
• Minimum emergency pack numbers set
• Review dates and triggers agreed

MISHAREN makes reusable surgeon gowns, drapes, covers and wrapping cloths to order at its own production unit in Konni, Kerala, and ships them to the UAE for delivery across all seven emirates, with the approved specification kept on record so top-up orders match. To quote against your par levels, visit the OT gowns and drapes page or contact us.