race safety

An Open Water Swim Safety Idea

February 26, 2016 By Larry Creswell, MD 1 Comment

As I mentioned in my last blog post, I recently visited in Tokyo with the Japan Triathlon Union about the issue of athlete safety. I had the chance to speak (albeit with translation!) with the race directors from many of Japan’s major triathlon races.

Dr. Masakazu Kawai, from the Yamagata prefecture, had a novel idea about swim safety to share with the group.

But first, to set the stage….

We know that being able to rescue a swimmer in distress in one of the most important aspects of an effective safety plan for a triathlon or stand-alone open water swim. Fortunately, in most cases, the on-water lifesaving team is able to spot swimmers in distress who might be struggling to swim, or wave, or even simply yell that they need help.

For the lifeless swimmer–the victim of drowning, near drowning, or cardiac arrest–identification of the victim can be much more challenging. And yet identification of the victim, prompt rescue from the water, and provision of CPR and use of the AED, if needed, is the chain of action that must be accomplished in just a very few minutes in order to avoid a fatality. This chain all begins with identifying the victim.

In a crowd of swimmers, oftentimes all wearing black wetsuits, it can be hard to spot the single athlete who has gone lifeless and who is floating, but no longer swimming. From afar, it can be difficult to tell whose arms are whose and it can be difficult to tell if a head is rotating to take a breath.

This is where Dr. Kawai’s idea might be helpful. He suggests the use of a small, inflated, brightly-colored balloon that would be attached to each swimmer’s swim cap. As the athlete is swimming, the balloon would bob left and right, with each turn of the head. If an athlete goes lifeless, the balloon would simply sit still on the top of the water. In a group of swimmers, then, there would be a very visible clue to a single lifeless swimmer–the single balloon that was no longer bobbing. This might be visible even from a considerable distance and allow early, perhaps immediate, recognition of the lifeless swimmer.

Watch a short video clip that shows the idea and let me know what you think. I’ll pass along any feedback to Dr. Kawai. He’s also looking for event organizers to trial his idea. We need simple, creative ideas like this.

Related Posts:

Triathlon, Open Water Swimming, and the Heart: What Can We Learn From Dolphins and Seals?

March 16, 2015 By Larry Creswell, MD Leave a Comment

A recent study about marine mammals caught my eye. I don’t know much about non-human biology and physiology, but this study on dolphins and seals may shed some light on the problem of fatalities during open water swimming or triathlon events.

The Study

A group of investigators headed by Terrie Williams from the University of California at Santa Cruz shared their report, “Exercise at depth alters bradycardia and incidence of cardiac anomalies in deep-diving marine mammals” in the January 16th edition of Nature Communications (1).

This group of investigators has been interested in the physiology of the so-called “dive response” in marine mammals. This is a response that is governed by the involuntary, or autonomic, nervous system, which has two antagonistic components: the parasympathetic nervous system and the sympathetic nervous system. As a group, the marine mammals depend on feeding by chasing pray to depths that can range up to 3,000 m. Even at lesser depths, these mammals must maintain a breath-hold under large hydrostatic pressures while they undergo extreme exertion to catch their pray. During a dive, breath-holding stimulates the parasympathetic nervous system to slow the heart rate (producing bradycardia). At the same time, the exertion required to chase pray stimulates the sympathetic nervous system, producing an increase in the heart rate. The current study offers the first detailed study of the interplay between the components of the autonomic nervous system during routine diving and feeding activity in these animals.

The investigators created an electrocardiograph-accelerometer depth monitor that was deployed on 10 Atlantic bottle-nosed dolphins and 3 Weddell seals. This device allowed high-fidelity recording of the heart rate, ECG, water depth, and swimming stroke frequency (a measure of exertion) during dives. For the dolphins, measurements were made for 74 dives to depths of up to 210 m. For the seals, measurements were made for 91 dives to depths of up to 390 m.

The Results

As expected, there was a strong relationship between diving depth and heart rate for both species, with heart rates falling during descent and reaching a minimum at the lowest depth of the dive. Superimposed on this effect was an additional effect of exertion. For the dolphins, the maximum heart rate was 1.7 to 3.7 times greater during periods of extreme exercise compared to gliding alone. For the seals, the maximum heart rate was 1.5 to 1.8 times greater during periods of extreme exercise compared to gliding alone.

The surprising finding was that cardiac arrhythmias occurred in more than 73% of the dives. The investigators defined arrhythmias to include ectopic beats or significantly increased variability in the interbeat interval (IBI). There were apparently no sustained or fatal arrhythmias., but there were discrete examples of “wandering pacemaker” and ventricular premature beats. In the Weddell seals, there were often patterns of alternating periods of tachycardia (fast heart rate) and bradycardia (low heart rate) during periods of constant, intense exertion.

The presence of cardiac arrhythmias was strongly correlated with increased depth of dive (parasympathetic activation) and increased exertion (sympathetic activation). As an example, cardiac arrhythmias occurred in 81% of the dolphin dives to >210 m but in only 26% of dives to <100 m.

The authors concluded that our previous understanding of the dive reflex in marine mammals was not totally correct. Given that these animals depend on diving for their food sources, the development of cardiac arrhythmias during feeding appears to be mal-adaptive. In fact, feeding might actually be dangerous.

My Thoughts

At first glance, the physiology of the diving response of dolphins and seals during feeding seems far afield from open water swimming and triathlon. And moreover, we already know about the development of cardiac arrhythmias during submersion in breath-holding humans as well as other marine species. The important observation here, though, is what I might call “irritability” or “instability” in the heart rhythm during periods of intense parasympathetic and intense sympathetic activation….and that’s the possible link to human fatalities during open water swimming or triathlon.

We know from autopsy reports of triathletes who’ve died during the swim portion of an event that there are sometimes only subtle abnormalities of the heart, and often nothing that seems explanatory. That leaves us in a difficult position to explain such deaths. In a previous blog post, I wrote about one very plausible hypothesis. Two UK physiologist,s X and X, proposed the concept of “autonomic conflict,” where a surge in both the parasympathetic and sympathetic stimulation of the heart might lead to a fatal arrhythmia. I’ve been intrigued with this hypothesis because it seems to fit many of the observations made about the swim victims. It is easy to see where exertion, cold water, anxiety, etc. might lead to strong sympathetic activation. And it’s equally easy to see where facial wetting, water entering the mouth/hypopharynx/nasopharynx, and breath-holding, even without diving, might lead to strong parasympathetic activation. In that instant, in an athlete with some sort of susceptible heart, a fatal arrhythmia might occur.

The new observations about the dolphins and seals seem to play into this hypothesis.

2. Triathlon Fatalities: 2013 in Review

Reference:

1. Williams TM, Fuirman LA, Kendall T, et al. Exercise at depth alters bradycardia and incidence of cardiac anomalies in deep-diving marine mammals. Nature Communications 2015;6:6055.

Mixed Emotions About The Medical Tent

September 17, 2014 By Larry Creswell, MD 4 Comments

I’m fascinated by the medical tent at endurance sporting events. Maybe that’s not surprising. After all, I’m a doctor and an athlete.

I have mixed emotions about the medical tent, though. Maybe you do, too. Let me explain….

Dr. Laird and the Kona Medical Tent

I got to thinking about the medical tent this past month when I listened to a talk given by Dr. Robert Laird, the long-time (now retired) medical director for the Ironman World Championship race in Kona. He gave a talk at a sports medicine symposium held in conjunction with this summer’s Challenge Atlantic City events. He told the ~23-year history of medical support for the Ironman race, beginning with its first year in Kona in 1981. That year, Dr. Laird stood on the pier watching the swimmers, dressed in running gear, stethoscope around his neck, cap on his head….and he alone was the extent of the medical support.

Of course, today it’s much different. On race day, there is a 50- to 60-bed field hospital set up in a tented area across from the Kailua Pier. It’s arranged in pods of 6 patient beds and staffed with many physicians, nurses, physical therapists, and non-medical volunteers as well. On race day, it’s the 3rd largest “hospital” on the Big Island of Hawaii. And on race day, up to several hundred athletes among the nearly 2,000 participants in the race receive medical care there.

The medical support team also has a fleet of makeshift “ambulances”–rented white vans with a temporary red cross affixed to the side. Without these vehicles, the need to respond to athletes on the 112-mile bike course or 26.2-mile run course would overwhelm the resources of the local EMS system.

If you’re an athlete with medical needs on race day, the setup is awesome. In truth, the Ironman event as we know it today would be impossible to stage without this elaborate medical support.

My Own Medical Tent Memories

Thankfully, I’ve avoided the medical tent as a patient. I did take a break at a medical aid station along the run course at the 2012 Ironman New Zealand race when I was feeling poorly. But after a cool refreshment, some much needed shade, and a short break, I was able to continue along my way.

I’ve waited near the doors of the medical tent on a couple occasions, though, while my athlete friends were receiving treatment. I remember my buddy, George, losing 12 pounds during the Ironman New Zealand race in 2007 and needing rehydration. I also recall my friend, John Pendergrast, an ophthalmologist, needing treatment for a couple hours after finishing the Ironman South Africa race. Our small group of traveling partners waited anxiously to be sure that John was okay.

I volunteered once in a major medical tent–for the Ironman Florida race. I worked the 6 pm to midnight shift. My lasting memory will be of the athletes who arrived at the finish line and then collapsed. On a day with high temperatures in the gentle 70’s I was surprised at how many athletes arrived at the medical tent at the finish line severely hypothermic and dehydrated. It seemed that the athletes who were worst off were those who arrived after finishing the race in 10-11 hours or so. Perhaps the later arrivals had gone too slowly to get “messed up.” We treated a bunch of athletes that night.

I’ve enjoyed reading the accounts of others who’ve worked in the triathlon medical tent. Check out the report by professional triathlete and physician, Tamsin Lewis.

Marathon Medical Tents

Of course, the medical tent today isn’t confined to triathlon. There is elaborate medical safety planning for the major running races, too. There is often a medical tent at the finish line of the big city marathons and these are often staffed, at least in part, by volunteers.

I recently attended a lunchtime lecture given by one of my cardiology colleagues who had volunteered at the medical tent for the Boston Marathon. There’s a sports medicine symposium before the race and the attendees are offered the opportunity to volunteer in the medical tent. This gives physicians a chance to put into practice what they’ve just learned. Listening to his tale, I get the impression that virtually any medical problem can manifest during the marathon, but that dehydration and heat-related illnesses are the common medical ailments. He shared (and I’ve heard from others as well) that ice baths for rapid cooling of victims with severe heat-related illness probably make the difference for survival–that the EMS system and local hospital emergency rooms might not have the available resources to get athlete patients cooled so quickly. That’s an eye-opener.

Malpractice Insurance Issues

I’ve often wondered–and even worried–about the issue of malpractice insurance coverage for physician volunteers at medical tents. It’s one thing if you’re an emergency physician or sports medicine physician. But it’s another situation entirely if you’re volunteering in a capacity outside your specialty–and perhaps outside the state where you’re licensed. The issue would seem to be relevant not only to physicians but also to nurses and other licensed healthcare professionals as well.

It would be interesting to know if there are instances of malpractice lawsuits brought by athlete-patients against medical tent volunteers. I’m told by the folks at USA Triathlon (USAT) that they’re not (yet) aware of any instances.

In order to encourage volunteer participation by medical professionals at triathlon medical tents, USAT has organized a malpractice insurance coverage opportunity. This opportunity hasn’t received much publicity. For a very modest premium, any licensed medical professional can obtain insurance coverage in situations where their own policies wouldn’t be applicable. I bet this would help put some potential volunteers’ minds at ease and encourage their involvement.

The Mixed Emotions

So, back to the mixed emotions. No doubt, the medical tents at triathlon and major running events provide a useful and needed service. In some cases, it would be impossible to hold events without an organized medical safety net that includes an on-site medical tent. And no doubt, countless athletes have benefitted from care they’ve received by volunteers at these medical tents. So, in the sense of providing a safety net for participants, the medical tent is great.

But on the other hand, I have to wonder if the very existence of the medical tent and ready availability of volunteer medical care doesn’t encourage unsafe behavior on the part of athletes or event organizers. I also wonder how outsiders view this whole enterprise. Surely, if intravenous hydration is required by large numbers of participants just to complete an event, there must be something wrong–either in the venue, the weather conditions, or the preparation of the athletes. Yet I hear many athletes talk casually about how they’ll “just get an IV” after the race.

At any rate, this is all food for thought. I’m intrigued by the medical tent. I hope it’s there when I need it, staffed by capable healthcare professionals. I’ll probably volunteer again, too. But I’ll also have some nagging worries.

Some Great New Videos from WTC SwimSmart Initiative

July 21, 2014 By Larry Creswell, MD Leave a Comment

Here’s a quick update from the World Triathlon Corporation (WTC) SwimSmart initiative. They’ve put together a YouTube playlist called “SwimSmart Saturdays,” a 9-part series of short (~1-2 minute) video clips that illustrate their 9-point checklist for race day swim safety:

This is all great advice for triathletes looking to have a safe day at the race.

Related Posts:

1. Swim safe in 2014

2. USAT and race safety

3. Triathlon fatalities: 2013 in review

USA Triathlon and Race Safety

May 22, 2014 By Larry Creswell, MD Leave a Comment

There is a great article about triathlon race safety in the Spring 2014 edition of USAT Magazine. The article shares strategies for athletes, event organizers, and USA Triathlon itself to help ensure everybody’s safety this triathlon season. This is must reading for the triathletes out there!

Download the USAT-Safety-Article.