Several years ago I went to a continuing education lecture with a “surgery updates” session, and the thing I took away from it was this: that waterless surgical “hand rub” formulations are more effective than traditional wet scrub with chlorhexidine, betadine, or the like at reducing skin microbes on surgeon’s hands.
The speaker said that not only were these products more effective, but that they were also cheaper than wet scrub. This sounded great, so I looked up prices and realized that the price comparison was only true if one was comparing pre-packaged sterile chlorhexidine-impregnated scrub sponges to the waterless products. For those of us who were using chlorhexidine scrub “straight from the bottle” on reusable scrub brushes, the waterless hand rubs were much more expensive.
What are surgical hand rubs?
Surgical hand rubs are generally alcohol-based and may also contain chlorhexidine. These products aren’t the same as over-the-counter alcohol-based gel hand sanitizers or similar products. Some of the companies that make surgical hand rubs also make similarly-named hand sanitizers for non-surgical use—basically, for hospital worker hand sanitation. For example, Sterillium makes a Sterillium Rub Surgical hand scrub as well as a Sterillium Comfort Gel– the first costing $75-$125 per liter, the second costing about $18-$30 per liter. The lower-cost similar products may be tempting to purchase, but they generally aren’t capable of killing as many microbes as their surgical counterparts, and may also contain user-friendly emollients that may increase acceptance but decrease effectiveness.
How have surgical hand rub formulations been made accessible?
In order to address the problem of cost of surgical hand rub in developing countries, the World Health Organization published guidelines on local production of suitable formulations to be used for waterless surgical hand preparation. However, the WHO formulations failed to meet the European standards in certain measures of efficacy and duration of activity, so other authors developed updated hand rub formulations based on WHO formulas that meet European standards. When we wrote The Association of Shelter Veterinarians’ 2016 Veterinary Medical Care Guidelines for Spay-Neuter Programs, we included reference to these Modified WHO guidelines for hand rub formulations as an acceptable method of hand preparation in HQHVSN programs.
For the spay neuter veterinarian (or any veterinary surgeon) with limited budget, these modified formulations sound amazing: affordable, simple, effective, used safely in human surgery all over the world. But as soon as you look at the front page for necessary ingredients, the task gets daunting. Where do I find 99.8% pure isopropyl alcohol or 96% ethanol? What if I don’t need 10 liters at a time? What if there was a way I could make the same end product as in the modified hand rub formulation paper, but entirely out of ingredients I can buy over the counter at the local Walmart?
So I started doing some math and realized that I could mix bottles of two standard concentrations of drugstore isopropyl alcohol to make the 80% (volume/volume) (equivalent to 75% weight/weight) isopropyl alcohol recommended by the modified formula article without ever having to add water to the formulation. By using commercially available pre-measured sizes and concentrations of alcohol, the process of mixing is super simple– once I’ve mixed the alcohol, I use syringes to draw up and add the appropriate amounts of peroxide and glycerol.
Here is the final formulation:
Modified World Health Organization isopropyl alcohol surgeon hand rub
1 quart (946 mL) 91% isopropanol
1 pint (473 mL) 70% isopropanol
62 ml H2O2
10.8 mL glycerol (also called glycerine)
Mix all ingredients together–I use a clean gallon jug for mixing and storage of the formula, and dispense into a repurposed hand sanitizer dispensing bottle for daily use.
Yield 1492 mL 79.9% (v/v) isopropanol with 0.1246% H2O2 and 0.724% glycerol
Results
I’ve been using this hand rub formulation for several years now. Of course, as with any waterless hand rub or scrub formula, it’s important that you have removed any gross contamination (in all senses of “gross”) from your hands before using the formula.
I have appreciated how easy it is to re-scrub compared to when I used water and chlorhexidine scrub to prep my hands for surgery. I don’t re-scrub between each surgery, but I will if I break sterility during my surgery day or if the indoor temperature is hot and my sweaty hands won’t go into my non-powdered surgical gloves. The isopropyl alcohol smell with this formulation is strong, so be ready for that. The skin on my hands hasn’t been bothered by the formulation and is actually less dried out than when I used chlorhexidine scrub, even though I use this product more often (again, because of the simplicity of scrubbing out and scrubbing in).
I hope you find this information useful!