Slides from my presentation at the annual meeting of the Texas Medical Association.
I’ve written here before about austere wound care, and one of the important comments I received was “irrigate with water clean enough to drink.” That’s a very valid point, as you don’t want to introduce new pathogens into the wound.
However, recommendations on irrigation volumes for serious wounds, ie open fractures or gunshot wounds, is to use roughly 10 liters of water for each wound. Not everyone wants to lug around 22 lbs of water just in case there is a serious wound, and heaven forbid there be multiple wounds, as is common in military operations. So these authors set out to investigate whether using field water to make one of the oldest irrigation solutions out there would be suitable. Dakin’s solution was developed in WWI by the Henry Dakin for the French, as a means to decrease wound infections for soldiers injured on the battlefield. It reduced deaths and amputations, and changed wound care from “leave it alone” to “clean it out” forever.
Back to the current study, they took field water from 5 sources, and cultured them for pathogens. Then they added enough bleach to make a 0.025% hypochlorite solution, and recultured the samples to observe if there was any effect. Certainly the treatment was effective, as they took water that had a mean pathogen concentration of 12.4×10^3 CFU/mL to zero pathogens. One of their treatment samples grew out bacillus, which was not present before treatment, so they chalked that one up to airborne contamination.
What this study demonstrates is, we can decrease what we carry from 10 liters of water per wound to 50 mL of household bleach, since that is all it takes to make the 0.025% solution. Of note, you could also drink this water safely, although the article does not mention that.
Treatment of Field Water with Sodium Hypochlorite for Surgical Irrigation
You’ve probably heard of it, or seen pictures of it on various internet feeds. But how many references have you seen in the medical literature? They’re sparse at best, which is part of the reason I haven’t written about them yet.
Does this mean that their use hasn’t been recognized in the medical literature? Far from it. This paper from 1925 discusses much of the history (to that point) of using ant heads as wound closure devices. What may surprise you is how long it has been in the literature. You may also be surprised that it was written by an ichthyologist, who apparently just found this interesting and decided to publish it in JAMA.
The use of ants as sutures likely dates from prehistoric times. It seems fairly easy to go from “this big ant bit me and it pinched the skin” to “lets use this to close wounds”, but most facts that seem simple after being established generally weren’t. Since we have no evidence of the first use, we have to go to the first recorded use. This falls to the Artharva Veda, circa 1000 BC. However, they weren’t using ants for skin wounds, they were using them to suture intestinal wounds after surgeries. It goes without saying that they probably didn’t start with that, so it had likely been in practice for some time prior.
It is possible, then, that the use of ants in surgery in the Mediterranean was learned from the Indian practices. Arabian medicine had translated the Hindu literature by 600 AD, and many recorded uses into the middle ages were from Arabic physicians. From there it spread into parts of Europe. The use in surgery persisted until the early Renaissance.
What made them stop? This article contends that a few high-ranking surgeons decided against them for a myriad of reasons. Theodoric rejected Arabian medicine, de Chauliac felt that they were rejected by the body, di Vigo felt they were obsolete, Fabricius felt the mandibles relaxed too much after the ants died (and were also hard to source in winter), and Purmann ridiculed them in his books. Most of these manuscripts were published (or republished) around 1500. Gut suture had also become more common by then, and was much easier to obtain.
Their use in skin continued in austere environments. As South America was explored, use of ants by native peoples was noted from the 1800s on. Concurrent use was still occurring in Algeria and noted by the French Foreign Legion. Their use was also described in Greece in 1896, as wounds were still being dressed by barbers according to local customs. That one comes from the Journal of the Linnaean Society of London, so you may have missed it on your feedly.
So why don’t we see articles discussing it now? Because it’s an established fact at this point. You’d be hard pressed to get more than a case report out of using ants as sutures, unless you were going to write a review article. And since much of the literature (including this article) isn’t accessible on pubmed, it becomes a scavenger hunt to get enough sources. The author of the paper had to look at the originals at the New York Academy of Medicine. Many are written in other languages, so you have to trust that the translation is correct (or translate the original yourself) before citing it.
Now, if you want to use ants to close a wound, you’ll want the right kind. Generally you would ask locals what they’ve used in the past, as naming species is unlikely to help you. Driver ants, army ants, and bullet ants are a few of the types that have mandibles big enough to close a decent skin wound.
The image to the left shows a bunch of the wrong type of ants, and one that is suitable, even though they’re the same species of army ant. Once you’ve found a suitable ant, pinch the wound closed, and hold the ant by the thorax (using something other than your fingers preferentially). You’ll want to be incredibly careful with the bullet ant, as it has the most painful sting of any hymenoptera, hence the name. The mandibles will usually be open in a defensive position if you’re holding it. Once the mandibles are near the skin, the mandibles will clamp shut, holding the wound closed. Then lift up the thorax and pinch off the body, leaving just the head and mandibles. Repeat as needed to close the wound, and there you have it.
You’ll of course want to irrigate the wound with water clean enough to drink prior to closure, as has been discussed before here. Also, don’t try to suture intestines with ants. That is well beyond what I would recommend in the wild.
Stitching Wounds with the Mandibles of Ants and Beetles
Wounds happen out there. Even with maximum preventive measures, they’re inevitable, so we should definitely know how to manage them appropriately.
This handy little report talks about a Grand Canyon boatman who injured himself at the beginning of a trip down the Colorado. It goes downhill from there, but it is a useful case to point out the things they didn’t do right, and did do wrong. The narrative is also mostly written by the river guide himself, and the style is quite humorous.
Serendipitously, or so he thought, there were two doctors on the trip, one of which whipped out his suture kit and fixed the rather large bleeding wound on his shin. I don’t have a problem with closing the wound, as it was large and likely to cause problems if left open.
What did they do wrong? First, they didn’t irrigate the wound. It goes without saying that the raft, the pack, and the Colorado River were not sterile, and thus the wound wasn’t clean either. They also shaved his leg with a razor, because apparently JCAHO was going to make a trip to the park that day. Must have left the batteries out of the electric clippers.
They correctly covered the wound with Tegaderm and Coban for protection on the first day, with subsequent dressing changes. 4 days later, the wound developed cellulitis, so he was started on Bactrim (TMP/SMX). It wouldn’t be my first choice for cellulitis, but it isn’t the worst drug to use as it covers Aeromonas. Levaquin (levofloxacin) would be great, or just adding Keflex (cephalexin) to the bactrim for better gram positive coverage coverage.
Two days later the cellulitis is progressing even with antibiotics, and now there is a pitting edema below the wound. Too late to evacuate that day, they elect to open the wound that evening. Anesthesia provided by gin and tonic. They irrigate using Betadine and pack it with Betadine-soaked gauze. The tissue-toxic solution could certainly reduce wound healing, and I can’t recommend using it. Using a squirt gun for higher pressure irrigation is a neat trick though.
Azithromycin is added to the antibiotic regimen, likely because it’s all they had. The next morning he is flown out. The good news is that after a washout in the OR and two days of wound vac therapy, they get the skin closed and it heals nicely.
Recap of important points for austere wound therapy
- Irrigate with clean water, but nothing toxic. You want to clean and promote healing, not kill tissue.
- Consider prophylactic antibiotics for dirty wounds that can’t be cleaned, especially penetrating injuries in water.
- Use occlusive dressings. They promote healing and decrease infection rates.
- Wounds less than 1 inch do not need closure, as cosmesis and infection rates are similar open or closed. Close if in an area prone to reopening certainly. Sutures, adhesive strips, and skin glue are all similar in efficacy if used appropriately.
They Had Me in Stitches: A Grand Canyon River Guide’s Case Report and a Review of Wilderness Wound Management Literature.