Monthly Archives: July 2016

SteriPEN, convenient or worthless?

Clean water is of utmost importance, whether you’re backcountry hiking, camping, or travelling abroad. And there are many ways to disinfect water, including chemical tablets, mechanical filters, simply boiling, and ultraviolet light. And while we know that UV light from the sun works with enough contact time, does a handheld UV light work well enough to be safe?

They’ve been around since the late 90s, but decreases in size and cost have made them more popular recently. They are lighter than ceramic filters, don’t require heating and then cooling the water, and they don’t leave a funky taste in the water after use. And while you can go to SteriPENs’s website and see a bunch of articles they sponsored showing how awesome they are, it’s nice that an independent group has finally looked into their effectiveness.

One of the things the article points out is that UV light is bacteriostatic, not bacteriocidal. Their DNA is damaged, so they can’t reproduce or cause infection (probably), but the water is disinfected, not sterile. Also, while still effectively treated by UV light, viruses and spores require much higher doses to be inactivated.

They tested the function against of the SteriPEN against water bottles contaminated with Escherichia coli, Staphylococcus aureus, and the spore of Geobacillus stearothermophilus. Using 1 L bottles in 3 different styles (wide mouth reusable, narrow mouth reusable, and disposable narrow mouth bottles), they either agitated as per the instructions for the device, or let the water remain calm. For wide mouth containers, you can stir. With narrow mouth bottles, you need to plug the mouth with the pen and invert and shake. However, knowing that many people don’t do this, they also did a test by simply stirring the narrow mouth bottle as well. They also measured the spectrum emitted by the device during use.

Used correctly the SteriPEN works pretty well. Bacteria counts were reduced more than 99.99%, but spores were only reduced 99.57% on average. If you don’t agitate the water, this drops to 94.2% on average. The SteriPEN does emit its maximal intensity of UV at 254nm, which is the most efficient wavelength for bacterial DNA. And in a bottle made of glass, PET, or metal, there’s no risk of UV injury to the user, as it’s all blocked. However, in a big open-topped pot, there’s a risk of UV emission that could be hazardous to the eyes. Thankfully, the device won’t turn on if not immersed in water.

Therefore it is ok to use a SteriPEN to disinfect your water, as long as you’re doing it right. You’ve got to agitate the water, not just put it in and let it sit there. These authors also didn’t test against viruses, but the manufacturer does have data, and since this paper replicates some of their other results, it’s not unreasonable to state that it likely works against those as well.

Downsides are a few. 4 AA batteries only gives you 100 cycles and the bulb is pretty fragile, so pack extras. It doesn’t filter out toxins, and turbid water decreases efficacy, so you might night a filter anyway. This particular device has 2 settings, 90s of light for 1L containers, 48s for 0.5L ones, so you’ll need to make sure you have it set for the correct size as well. Finally, it doesn’t keep the water disinfected forever, so be aware that the water can become contaminated again and require re-treatment.

Drinking water treatment with ultraviolet light for travelers – Evaluation of a mobile lightweight system
And it’s FOAMed!

Dislocations? Put your shoulder into it!

Shoulder dislocations. Few procedures are more fulfilling in the emergency department. A little intra-articular lidocaine, some ketamine (always the answer), some propofol, and you’ve nearly instantaneously fixed a painful condition. Thankfully we’ve moved on from the barbaric techniques pictured below.

But this blog isn’t about reducing a shoulder in the emergency department using procedural sedation. It’s about the wilderness. So what are you supposed to do when it happens to someone on your trip, or heaven forbid, yourself? Between skiing, climbing, kayaking, mountain biking, and Pokemon Go, there are lots of activities that can result in shoulder dislocations at a scene distant from advanced medical care.

There are a few options other than openly cursing. At least one doesn’t have a name yet, and another is the Davos Technique, which was brought to my attention by none other than Tim Horeczko (@EMtogether). There are more, but I’m only going to talk about these two today.

First is the sin nombre technique, which I will refer to as the German technique after the location of the authors. It involves the following steps:

1.The practitioner holds the patient’s wrist with the left hand (in the case of a left shoulder dislocation) and the patient’s elbow with the right hand.
2.With the elbow in 90° of flexion, the glenohumeral joint is flexed forward to 90°.
3.While still in flexion, the glenohumeral joint is adducted until the elbow reaches the midline of the body; it is important to continue this movement until this landmark is completely reached.
4.Then, internal rotation of the shoulder is performed. During this step, the patient’s elbow must stay at the landmark described above. At 25° to 30° of rotation, a mild resistance is usually encountered.
5.The last step of the maneuver consists of applying a constant internal rotation pressure to overcome this mild resistance without pain. Reduction is usually achieved at approximately 30° of internal rotation.

For the visual learners, it is demonstrated in the video below.

The authors published their paper after a 50 month prospective observational trial that enrolled 39 patients older than 16. Of note, no pre-reduction xrays were performed, diagnosis was made clinically by deformation, pain, and decreased range of motion. All reductions were made without sedation, analgesia, or anesthesia, including alcohol.
Of the 39 dislocations, reduction was 95% successful on first attempt, and success was 100% on the second attempt on the 2 that failed the first. Mean dislocation time was nearly 4 hours, and reduction time was 6 minutes. Pain on a visual analog scale was low, and at least according to their followups, there was no need for surgery after reduction, nor were there any complications.
100% success without medications puts this at the top of list of possible techniques, tied with scapular manipulation. The downside to this technique (and many others) as far as wilderness medicine goes is that it pretty much requires a second participant. The arm movements would be nearly impossible to perform on yourself.

The Davos Technique is pretty trendy, as it just came out in JEM. However, it has been around awhile first described in 1993 by Boss, Holzach, and Matter. They worked at Davos Hospital. Their reduction rate was 60%, and further descriptions of this maneuver had similar rates. It is performed by following these steps:

The patient is sitting on his bed holding his injured extremity with his other hand. He is asked to flex his ipsilateral knee as much as possible and, with a little help, he passes both hands in front of the flexed knee. The hands are then tied together using an elastic band, preferably at the level of the wrist joint and not at the fingers, as this way the patient doesn’t have to concentrate on keeping the fingers crossed, and thus, can be more relaxed. Another important point is that the elbows should be kept close to the thigh, as this way the shoulders can be more relaxed. The two wrists can either be tied on the proximal tibia or simply held in place by whoever is treating the patient. At that point the physician can sit on the patient’s foot and instruct the patient to lean his head back, let his shoulders roll forward, extending the arms and relaxing all the muscles. By extending the neck, the patient exerts a constant traction on the injured shoulder and the dislocation is reduced without any need for additional maneuvers on the physician’s part. Once the shoulder is reduced, it is immobilized in a sling, and postreduction x-ray studies can be obtained.

Or, again, watch the video.

This paper retrospectively evaluated 100 patients with shoulder dislocations who had the Davos Technique performed on them over a period of 18 months. 82% of them had received analgesia prior to reduction, with morphine given nearly 40% of the time. Reduction was only successful in 86 patients, and they don’t list the number of attempts of the Davos Technique. 4 of them were reduced using a different technique, and the last 10 went under general anesthesia.
However, 8 of the 14 failures had psychiatric problems or dementia, and for a technique that requires patient effort, this could drastically decrease success rate. Of note, the 18 patients who didn’t get pain medications were all successful with Davos. Their complication rate was zero, just as with the German technique. It seems that this could be successful as an auto-reduction by interlocking your fingers, but some people may not have the strength to keep their hands together. The new authors recommend against it specifically. If you use the band, it again requires a second participant. I can’t read in German, so if anyone wants to pull the original Boss et al paper, let me know what their thoughts were on the matter.
In the end, it looks like both techniques are suited for wilderness reduction of shoulder dislocations because they are well tolerated, have minimal apparent complications, and don’t require the use of medications.

You’ll note that I recommend either of these techniques over the Riggs method, demonstrated below.

And should you think this will never happen, think again.

Reduction of Acute Shoulder Dislocations in a Remote Environment: A Prospective Multicenter Observational Study.
Also available as FOAMed!
Reducing a Shoulder Dislocation Without Sweating. The Davos Technique and its Results. Evaluation of a Nontraumatic, Safe, and Simple Technique for Reducing Anterior Shoulder Dislocations.