Based on recent events in Minneapolis and that ice season is upon us, it is a good time to review key considerations for advanced ice rescue operations. To do that, let’s focus on the worst-case scenario: A reported victim who has fallen through the ice and is not visible on the surface when crews arrive.
Each department’s medical director and medical protocol will drive how aggressive they are on in accessing and treating victims who have fallen through the ice.
If there is even a remote chance that the victim is under water, establish a timeline. This should not be a lengthy process. Successful revivals have taken place on cold water drowning victims who were submerged over an hour.
Here’s part of a case study published by Science Nordic.
“Anna Bågenholm, a medical doctor, lost control of her skis on a mountain ski tour outside of Narvik in 1999. At 6:20 p.m., she fell through the ice on a river, head first. When her companions found her they saw just her skis and legs. The rest of her body was locked in the grip of the icy river.
“Bågenholm was lucky in many ways: she landed on her back under the ice and was conscious long enough to find an air pocket. She was unconscious for 40 minutes before her heart stopped, but her core temperature was so low at that point that her body’s oxygen demand was greatly reduced. Finally, after 80 minutes, her ski companions managed to chop her out of the ice. They were all doctors and immediately started CPR.
“Her core body temperature was measured at 13.7 °C. She showed no signs of life. She was pale, wet and ice-cold, and her pupils were dilated. Luckily, Bågenholm ended up at the University Hospital of Northern Norway, where emergency doctor Mads Gilbert, who is now also a researcher on the Cold Water Survival project, and the rest of the medical team knew that a hypothermia patient first has to be warmed up before being declared dead.
The doctors continued CPR while they warmed up Bågenholm. Her heart started beating on its own again at 10:15 p.m.”
Survivial chances
This is the longest documented resuscitation to my knowledge. There are other cases with longer submersions, but they resulted in varying degrees of brain damage. This patient made a full recovery and continued to practice medicine.
What we can take from this is that we owe it to the victims to give them a fighting chance. Even if our timeline is beyond a few hours, the timelines for cold water drowning are still relatively vague.
That’s why it is important to understand why the human body responds so uncharacteristically to cold water. Here’s more from Science Nordic.
“Patients with dramatically low body temperatures and who suffered a cardiac arrest have survived for up to six hours with continuous CPR. And they were able to return to a full life after being resuscitated,” says Torkjel Tveita, an attending physician and professor at the University of Tromsø.
“In this case, think of oxygen as the body’s gasoline. You use more fuel driving at 90 kilometres per hour than at 30 kilometres per hour. The same is true with the body. Circulation naturally decreases as a consequence of cooling, cellular metabolism is reduced and therefore the body uses less oxygen,” explains Tveita.
“The hypothesis is that by providing CPR to maintain blood circulation in a body that is cooled to 25 °C, we can reach virtually 100 percent of optimal oxygen transport,” he says.”
So, we know not to hastily categorize these events as recoveries and go rapidly into rescue mode. That requires some quick decisions about resources and getting them to the scene immediately.
Call for a dive team that is qualified in ice diving and ensure that you have a lightweight, inflatable craft that can support both surface operations and dive operations. Having multiple crafts on scene is optimal.
Another key resource is an additional warming vehicle. This is not just important for personnel, but also for gear.
Once your resources are requested, prepare to support the dive operation while simultaneously performing surface rescue attempts.
Surface rescue operations
Evaluate the condition of the ice and determine the best route to the hole. I prefer to follow the victim’s path if I can identify it.
If there is snow on the ice and you can see the victim’s tracks, you have a proven route. If the victim is a child, consider the weight differential between the rescuers and the victim and proceed with caution.
This initial access must be quick. This usually means having a primary rescuer advancing to the victim and a primary back up rescuer on shore tending the rescuer. The primary rescuer should have a reaching device that is ideally as deep as the body of water.
This is ascertained through planning and on-scene interviews with a competent person. Obviously, this is not always feasible so grab the longest tool you can get your hands on.
If the ice cannot be efficiently traversed without breaking through, the rescue crew can wait for an inflatable craft. This should be a rare choice on flat or static water and should be a prominent choice on moving or dynamic water.
Always be aware of current. Falling through the ice in current presents a much more lethal environment to rescuers than flat water. So, having a large buoyant platform to work from over current is much safer.
In either case, adequate rope and accessories are needed to tether the primary rescuer and/or their craft to shore. This line must be tended at all times by the back up rescuer; have contingencies in place for an adequate haul system or team to retrieve the rescuer, their craft and the victim.
Concise communication
Ensure that communication sequences are reviewed prior to deployment and have back up communication plans in place. The OATH acronym is the common communication tool in this setting because of its versatility. It can be communicated through helmet taps, rope tugs or whistle blasts.
- O: (one tap, tug, blast) OK.
- A: (two taps, tugs or blasts) Advance.
- T: (three taps, tugs or blasts) Tension.
- H: (four taps, tugs or blasts) Help.
The goal for the primary rescuer is to get to the hole and probe for a victim. When using the reaching device to probe, remember to be gentle. The reaching device is most effective if it has a hook capable of bringing the victim up.
A chainsaw or ice saw is another important tool to take to the hole. Before expanding the opening, sweep the underside of the ice with your hand or tool to ensure the victim is not lodged against the planned cut area.
The best practice for expanding the hole is to wait until the divers have entered the water and cleared the cut zone.
Dive team support
If there is only one breach in the ice surface, then the entry point of the victim is known. However, multiple breach points may be present depending on the condition of the ice and the nature of the event.
In this scenario, shore-based personnel should triangulate the victim’s last-known location or entry point. This requires careful analysis of the scene and the competent person’s testimony.
Triangulation is accomplished by looking at the point on the ice where the victim was last seen from two perspectives. From each perspective, establish plot points on the shore that are easily identifiable.
One plot point will always be your own vantage point or where you are standing. The other will be something identifiable on the opposite shore directly across from your vantage point as you look at the last-known point.
Then shift significantly left or right to create a cross reference. If identifiable plot points aren’t present and you are dealing with open spaces, create plot points with markers or placed objects.
The second phase of prep work involves creating reference points for the divers. When divers are under the surface, tenders track their progress by watching their bubbles at the surface.
In ice diving, however, the diver’s bubbles will only be visible as they travel back to the entry point or breaches in the ice surface. A diver’s progress under the ice then becomes much more challenging from a communication and search pattern perspective.
Search reference points
Light from the entry point provides the diver with a point of reference. Creating strategic reference points for the diver will greatly facilitate their orientation and efficiency while searching.
This starts at the hole and progresses outward. The end goal should be to create a hub with spokes.
Visualize the entry point as the hub and then make lines that go away from the hub. The lines are generally created by shoveling the snow off of the ice in a clean line.
Determine the radius of the search patterns and create breaches in the ice at the end of the rays relative to the search radius distance. Each of these lines and points of light are great assets for the divers.
Lastly, ensure that you have a lightweight inflatable craft prepped and ready on shore to help transfer the divers, their attendants and their gear to the hole.
Remember to watch all of your personnel for environmental exposure. Appropriate PPE is a must.
Keep your people warm and buoyant with PFDs and good insulation. Helmets are really important on ice because slips are so common and the landing surface is hard.
Stay safe this winter and train hard.
