Contact with electrical current is the third-leading source of fatal incidents among arborists. About three-quarters of these incidents are aloft, either to a climber or aerial device operator. This means arborists must know how to perform aerial rescue. They also must have first-aid and cardiopulmonary-resuscitation (CPR) skills to respond to an injury.

Aerial rescue has gone through many changes since the beginning of the Electrical Hazards Awareness Program (EHAP). The National Arborist Association’s (now TCIA) 1994 EHAP required a rescuer to bring a dummy to the ground from a height of at least 35 feet in four minutes or less. The basis for this requirement was the thought that electric shock was the most common reason for an aerial rescue and the emergency was ventricular fibrillation (v-fib).

But electric shock is not the most common reason for aerial rescue, it is when the worker aloft is trapped and pinned. And, if the incident is from contact with an electric current, the emergency is typically burns, not v-fib.

This has changed our approach to aerial rescue. The TCIA EHAP requirement for aerial-rescue proficiency no longer has a time component. The emphasis is not speed but the safety of the rescuers and injured workers. It is also critical for arborists performing aerial rescues to be trained in first aid/CPR. Many aerial rescues are more complex than merely lowering an injured climber or aerial-device operator to the ground. The traumatic injuries or illness of the injured worker also must be addressed and treated.

ANSI Z133 standards and OSHA rules

Emergency-response and first-aid/CPR requirements for arborists are addressed in the American National Standard (ANSI) Z133 Standard for Safety Requirements for Arboricultural Operations under Section 3, General Safety Requirements. The Occupational Safety and Health Administration (OSHA) has these topics broadly addressed for line-clearance arborists under 29 CFR 1910.269, Electric Power Generation, Transmission, and Distribution.

Every company sending arborists into tree canopies must have emergency procedures in its policies that address responding to an injured worker aloft. The procedures may be for rescuing or assisting a climber, an aerial-device operator or both, depending on the company’s employment.

The training shall be conducted at least annually and documented by date, the type of rescue and who was in attendance. Responding to an actual aerial rescue may require more than equipment to access and lower a climber – a second saddle and climbing line, as examples – it also may require first-aid supplies.

First-aid kits

The first-aid-kit requirements are addressed in the Z, Section 3, General Safety Requirements, and OSHA under 1910.151, Medical services and first aid. A first-aid kit must have supplies sufficient for the number of workers and appropriate for first aid for the likely types of injuries at the work site. A reference OSHA frequently cites for minimum first-aid requirements is ANSI Z308.1, Minimum Requirements for Workplace First-Aid Kits. To see a related video, visit tcimag.tcia.org and, under the Resources tab, click Videos.

There are two classes of first-aid kits, class A and B. Class A first-aid kits are for typical workplace injuries. Class B is for workers in high-risk occupations. Companies engaged in arboricultural operations must comply with the requirements for a Class B first-aid kit.

Arborists are not office workers, where first aid may be more directed to minor cuts and strains. The numerous hazards during arboricultural operations – working at height, power equipment and being struck by heavy objects – means incidents may require treating severe bleeding and fractures.

First-aid training

A first-aid kit has limited value if no one has the training to treat injuries. So another Z requirement and an OSHA line-clearance requirement is that at least two workers, on each crew of two or more, be trained in first aid and CPR. The exception is that only one trained worker is required on a crew if all workers are trained in first aid/CPR within three months of their hiring date. The intent is to cover the occasional scheduling conflict where a new worker might be paired with a longer-term employee who has first-aid/CPR training. While this arrangement is acceptable, it is not ideal – what if the worker trained in first aid/CPR is the one injured?

The first-aid/CPR training required by OSHA must be through a recognized provider such as the American Heart Association, National Safety Council, American Red Cross or a private institution. The certification must remain current and valid, which generally means it must be renewed every two years, and it is held by the individual, not the employer. If a worker changes employers, they still have their first-aid/CPR certification.

Aerial-rescue precautions

Aerial rescue can be a high-risk operation for the injured worker and the rescuer. There are instances where injured arborists aloft had their medical condition made worse by careless lowering during the rescue. Rescuers have been injured or killed during an aerial rescue. Tragically, rescuers and persons playing the role of “victims” have been injured or killed practicing aerial rescue. This is the reason the “victim” should be a rescue dummy, not a real person, and speed should never be the focus or requirement for a practice.

Since aerial rescue is high risk, an important consideration is determining if the incident is a rescue or body recovery. Always attempt to communicate with the injured worker from the ground. If they can talk, they may be able to describe their condition. This information can be relayed to the 911 dispatcher, along with how high up the climber is and accessibility to the tree. This information can be invaluable to the fire/rescue and emergency medical services (EMS) personnel who are coming to the scene.

If the injured climber or aerial-device operator is unable to communicate and there are no apparent signs of life, it might be a body recovery. There is no need to risk crew members extracting a deceased worker from a tree or lift. This process can be delayed until first responders arrive. The difficult rescue decisions are for incapacitated workers who are alive, but their condition is not apparent from the ground.

Rescues involving electricity

Aerial rescues involving electric shock are ones with the greatest risks to the rescuer. A common double fatality during pruning or removal operations is an electrocuted climber or aerial-device operator whose would-be rescuer also is electrocuted. The rescuer died attempting to reach a dead co-worker. A key tenet for EMS is that their crew safety is the priority, next the bystanders, then the injured person.

Since the safety of the fire/rescue and EMS crews is paramount, a rescue will not be initiated until the power line is de-energized. While arborists were once taught to use a climbing line to pull the power line away from the injured worker, this is no longer an acceptable practice. Accessing an aerial-lift’s lower controls to separate the operator or booms from electrical contact is also no longer an accepted practice.

There are numerous scenarios when an arborist successfully accessed and extracted an injured co-worker. But often the best scenario is one in which a crew member remains on the ground during the rescue. A ground person is helpful in maintaining scene safety and guiding EMS and professional fire rescuers into the site. It also may be necessary to control the lowering line for the injured worker.

Common injuries requiring aerial rescue

While contact with electric current is the focus of EHAP, it is not the most common aerial rescue. Struck by a falling or swinging tree branch is the most common, followed by chain-saw lacerations, falls and electric shock. Electrical-contact injuries are often fatal, so many, but not most, are body recoveries. Electrical-contact incidents are also the ones with the highest number of rescuers killed.

A climber trapped and pinned by a cut branch is a common need for aerial rescue. The traumatic injuries associated with these incidents are fractures, lacerations and punctures. A common myth is that the average aerial rescue takes three-and-a-half hours. Most take far less time, but the ones that do take hours are often the trapped-and-pinned incidents.

One challenge to these rescues is removing a cut branch or tree top – which might weigh more than a ton – off a trapped climber without causing further injuries. The complexity of removing this wood is daunting. It is often best performed by arborists who have the knowledge and skills in rigging and saw handling to safely remove the weight off the climber.

Climbers also have had their trapped limbs amputated – by medically trained personnel – during these rescues. Starting IVs by placing a needle in a vein to deliver drugs has been performed on injured climbers while they are still in the tree. Trapped-and-pinned rescues have the best outcome when the knowledge and skills of both arborists and rescue/EMS/medical professionals are combined on the team.

Climbers, and occasionally aerial-device operators, fall into a tree. A climber takes an unexpected swing in a canopy and strikes the trunk or branch. An aerial-device operator falls out of the bucket and becomes tangled in branches before the fall arrest fully deploys. Common injuries associated with falls are fractures, lacerations and punctures, like those that occur in trapped-and-pinned incidents. These also may be complex rescues where the injured worker may have to be carefully extracted and packaged to prevent further serious injuries.

Electric-shock hazard

Electric shock is another hazard for climbers and aerial-device operators. Indirect contact with an overhead power line through a conductive tool or cut branch is the most common electrical incident to climbers. The most common electrical incident to aerial-device operators is direct contact with the power line. Electric-shock injuries in cases of contact with an overhead power line, either directly or indirectly, are typically severe burns and fractures.

Surprisingly, the heart may be beating normally following brief contact with the power line. The need for speedy lowering to initiate CPR is rare for an electric-current incident to arborists. Lowering the person to the ground within four minutes of the incident is not necessary. Instead, the focus is on delaying the rescue until the line is de-energized, and then the injured worker’s injuries are assessed and the rescue is performed.

Suspension trauma

Two other hazards for aerial-device operators are suspension trauma and mechanical asphyxiation. Suspension trauma is a familiar term to most arborists. Also known as orthostatic intolerance, it occurs when a worker is suspended by their fall-arrest harness and their legs are hanging. Climbers also can be left hanging from their saddles or harnesses.

The leg straps can press on the femoral arteries, restricting blood circulation. The relaxed muscles in the dangling legs may have the veins expand (vasodilation). The blood may pool in the lower legs due to the lack of muscular contraction, leading to an increase in metabolic waste and acidotic blood. The movement of the legs while walking prevents this pooling.

This was listed as a major concern to arborists but has been disproven. While syncope (fainting) can occur from hanging in a harness – in as few as 10 minutes – more serious injuries and deaths have not been well documented for arborists and construction workers. The caution against moving the suspended person to a horizontal position too quickly also has reduced in importance.

It is still a recommended practice, however, to have conscious workers hanging in a harness move their legs in a bicycle fashion or use a strap to push their legs against. Once on the ground, keep the worker in a semi-Fowler position for 30 minutes before fully reclining. The legs are stretched out on the ground, but the upper body and head are kept leaning back at about a 30-degree angle. Since EMS has already been called, they will arrive soon enough that the injured worker is still in the slanted position.

What has been better documented are serious injuries and deaths from improper attachment of the harness or positional asphyxiation. Leg straps adjusted too loose have resulted in blunt-trauma injury to the femoral artery when the straps are quickly made taut by a fall. If the dorsal anchor of the harness is too low – rather than between the shoulder blades – an unconscious wearer may have their breathing restricted.

Step and touch potential

Ground workers have suffered electric shock or been electrocuted during a rescue. While rare, the incidences are most common with aerial-device-operator rescues. When an aerial device is in contact with an overhead power line, the two hazards to ground workers are step and touch potential. Voltage is a difference in potential, and current can only flow when there is voltage.

Step potential is the difference in voltage between the two feet of a ground worker standing near an energized truck. The resistance of the ground means that the voltage decreases as the distance from the energized truck increases.

Touch potential is when a person touching the energized truck provides an alternate path for the flow of electricity. For instance, a ground worker touches the side of the energized truck as they climb up to assess the lower controls of the boom. Arborists were once taught to jump from at least 6 feet away to the truck to avoid being shocked. But the ground can have lethal step potential 20 to 30 feet from the truck.

Another technique was to shuffle to the truck – if the feet are kept together, there is no difference in potential – and then hop up onto the steps. This is dangerous and breaks the basic tenet of rescue – do not become the second victim.

No pole pruners or ropes

Using a pole pruner to reach the lower controls is impractical. The pole would need 30 feet of extension, and it is impossible to hold the pole with any precision at that length. Also, many lift devices require a button to be pressed on the lower controls before the control levers work. The rule for accessing an energized truck is simple – do not. The risk to rescuers is too high.

Arborists should never toss a rope over a boom or branch to break contact with the truck or operator. Even more dangerous is attempting to throw a rope over the overhead power line to break contact. Many arborist ropes do not meet the electrical performance properties defined by IEC 62192 or ASTM F1701-12. Even ropes that do meet these requirements may have their dielectric properties compromised by debris, surface contamination or water entrapment.

Aerial-rescue kit

A well-stocked, Class B first-aid kit should be part of every tree crew. The basic and minimum supplies for these kits are in Table 1 in the online version of TCIA’s EHAP module. These kits should be checked weekly to replace any used supplies. All supplies – even examination gloves – have a shelf life. Supplies should be replaced before their expiration dates.

The aerial-rescue kit also should include a dedicated system for climbing, if the crews have climbers. This kit needs at a minimum a climbing rope, friction device or lines, carabiners, saddle and lanyards. Many kits also include an insulated pole saw. This can be used to cut branches away from climbers trapped and pinned in a tree or aerial-device operators or climbers. The intent is not to use the pole to push the energized overhead power line away from the injured climber.

Aerial-rescue techniques

Climbing systems and equipment continue to evolve. Where moving rope systems were once dominant, now stationary rope systems are common. This means that anyone who might be called upon to assist in an aerial rescue, from a ground worker to a climber, must be familiar with the system and gear that the injured climber is using.

All climbers should be familiar with the use and limitations of any device they employ for ascending, descending or working from a canopy. A device may not be designed for two people – the rescuer and injured climber – to descend on, or it may require an extra friction system. Always read and follow the manufacturer’s instructions and understand the limitations of any part of the climbing system for use in a rescue.

The condition of the tree must be assessed from the ground before attempting a rescue. If a large cut or broken limb is pinning the injured climber, is the tree still safe to climb? If the tree is OK to climb, there are still other considerations. For example, will the anchor support the weight of a rescuer and the injured climber?

Climber rescues

There are several parts to the aerial rescue: ascending to the injured worker, assessing and supporting the worker and then descending. Or the rescue may involve ascending to the injured worker, stabilizing any injuries and awaiting professional rescuers.

One of the most basic aerial-rescue techniques for climbers is one in which the injured worker just needs some assistance during the descent. This lowering technique is called the double-climbing-hitch rescue. The injury might be heat exhaustion or a medical emergency. Each climber, the rescuer and the injured party, descends on their own system. The rescuer may need to control the descent of the injured worker, but it is a simple procedure.

More difficult are rescues when the injured climber is incapacitated. The decision to extricate and lower the climber is based on their medical condition and the stability of the tree. If the injured climber is severely bleeding or not breathing, there is a need to get them on the ground as quickly as safely possible. These rescues also may require the rescuer to support and stabilize the injured worker during the descent.

A ground worker may be involved in aerial rescues. Stationary rope systems (SRS) lend themselves to ground-worker participation in rescues. A ground worker can use a lowerable basal anchor to lower an injured climber. There are still significant challenges to these rescues. First, if the climber is incapacitated, they may sustain further injuries during the lowering as they strike branches during the descent. Second, the ground worker needs prior training in how to use the anchor and, equally important, when not to!

Aerial-device rescues

As mentioned previously, the lower controls should not be used to move a boom that is in contact with an overhead power line. Using the controls should be delayed until the power line is de-energized and this is confirmed by a utility representative.

Once the bucket is lowered to or near the ground, the next decision is whether to leave the injured operator in the bucket or remove them. This decision is based upon the injured operator’s complaints, the mechanism of injury and the extent of the injuries.

If the operator is complaining of neck or back injuries, it may be best if they stay in the bucket until EMS arrives – which should be quickly, as the second step in a rescue, after assessing the situation, is calling 911. If the operator was struck in the back, neck or head, and there are no potentially fatal injuries such as severe bleeding, leaving them in the bucket is the best choice.

If the operator is incapacitated and there is an emergency that cannot be managed in the bucket – severe bleeding from the legs or not breathing – then use the controls to tilt the bucket. The operator can be extracted following a similar procedure to the log roll. One worker has control of the head and calls the moves, and another worker (or two) slides the injured operator out of the bucket and onto the ground. This procedure can result in further injuries, so its use must be balanced with a great need to address a traumatic emergency

Self-rescue

Self-rescue is also an important skill for aerial-device operators and climbers. They must be prepared to initiate their own rescue or stabilize their injuries until they can be rescued. A common severe injury to aerial-device operators and climbers is a deep laceration from the moving chain of a chain saw. These injuries tragically become fatal if the injured worker is not treated quickly – within minutes.

Every climber and aerial-device operator should carry a soft (also called a wide or tactical) tourniquet in a pouch that can easily and quickly be reached. If these are applied quickly and properly, they reduce blood loss. The injured worker may be able to lower themselves or, if they become incapacitated, may still be alive when rescuers arrive.

Aerial-rescue practice

Arborists must practice aerial-rescue techniques appropriate for their company. Every member of the tree crew should perform the practice rescue within their capabilities. If the crew has several climbers, one or more can practice accessing and lowering the dummy. A crew with only one climber and a ground worker can practice SRS rescue, assuming the climber uses this system.

Working with rescue/EMS professionals

Rescue/EMS professionals conduct most aerial rescues. The tree crew sometimes assists them. But the degree of involvement by the tree crew is the prerogative of the professional rescuers. The decision whether the tree crew will be participants or spectators for the rescue depends upon several factors.

First, are the professional rescuers/EMS personnel familiar with the tree crew? Have they practiced together on rescues? The larger the community, the less likely they would have a chance to practice together. But, if the professional rescuers/EMS personnel have previously practiced with arborists, they have some familiarity with the industry and our capabilities.

Second, the crew members’ behavior on the site also plays a role in their participation. If they are swarming the rescuers, giving orders and telling them to hurry, they are going to be moved off the site very quickly. There have been instances when the rescuers called the police to remove a tree crew that was interfering with the rescue. Once the rescuers/EMS arrive, it is their site and under their control, not the tree crew’s.

Next up…

This article covers what to do when things go wrong around electricity – emergency response and aerial rescue. Part 8 of this series will cover safety standards applicable to tree work in proximity to electrical conductors.

John Ball, Ph.D., BCMA, CTSP, A-NREMT (Advanced-National Registry of Emergency Medical Technicians), is a professor of forestry at South Dakota State University.