The continuous conduit leading through a cave is known as a passage. Passages can be huge, with room dimensions so large it is difficult to see distant walls (Figure 46-2) even with a light, whereas just around the next corner, the passage can change to tight impenetrable cracks or a dead end (Figure 46-3). Some cave passages wander around in a maze-like pattern that may total many miles in an area as small as a few acres of ground. Other caves may go for miles in the same direction and contain dozens of miles of passage. Many caves are only a few hundred feet long and have only low, tight, belly-crawl passage. A passage that opens into a wide area is called a room, whereas a tight, narrow passage may be further described as a squeeze or crawl.

FIGURE 46-2 Typical large “room.”

(Courtesy Kris H. Green.)

FIGURE 46-3 Typical tight crack passage.

(Courtesy Kris H. Green.)

Caves are formidable, dark, and often dangerous for the unprepared. Considering that running, seeping, or standing water originally formed most caves, it is not surprising that water is a major part of many cave environments. Cavers and rescuers must be prepared to negotiate anything from crawls in water-filled tubes (Figure 46-4) to underground rivers so large that a boat is required.

FIGURE 46-4 Wet passages require appropriate clothing.

(Courtesy Kris H. Green.)

Caves that are no longer hydrologically active are called dry caves or dead caves because they are no longer in their formative state. Some caves are so dry that dust induces respiratory problems in cavers. Visitors to dusty caves should wear appropriate filter masks as a minimum level of protection from dust stirred up by the act of moving through a dry passage.

Temperature extremes are another common characteristic of caves. Caves tend to be at the mean ground temperature of the area. For the most part, U.S. continental caves run from cool to cold. Very warm climates, such as in Puerto Rico, sport warm caves, whereas alpine mountain caves in locations such as Montana measure close to freezing temperatures and may even contain ice. Caves found in tropical and desert environments can be so hot that cavers must wear lightweight garments to explore them—even then, these cavers are at risk for heat illness.

A common scenario in cave rescue is the concern for hypothermia. Most caves are cool to cold, but temperature differentials can exist within a single cave, depending on exposure, orientation, and water flow. Temperature differentials or pressure differences can result in winds flowing through cave passages. It is not uncommon for a caver to be supine or prone in 4 inches (1.6 cm) of 13° C (55° F) water with his or her back pressed against cold rock, facing a stiff breeze (Figure 46-5).

FIGURE 46-5 Close contact.

(Courtesy Kris H. Green.)

If not prevented, hypothermia will complicate any cave incident. An injured, less mobile person will not generate as much heat as usual in the cold, frequently wet cave environment. Party members and rescuers must work to prevent hypothermia as soon as any injury occurs.

Rescuers must also protect themselves from hypothermia. A common scenario is for a rescuer to carry a load of heavy gear rapidly through the cave, then sit in a cold, wet passage to wait for the next assignment. The sweaty rescuer is now subject to evaporative, conductive, and convective heat loss. The well-prepared rescuer dresses in layers, travels light, and adds or removes layers of clothing as needed.

Caves can be fragile, often heavily decorated with mineral formations that have developed over thousands of years. Cavers try to protect these formations whenever possible by avoiding walking on or touching delicate areas or otherwise altering the cave. Even natural skin oils deposited by human hands can alter the growth of an active formation. The caver’s motto, “leave nothing but footprints, take nothing but pictures, and kill nothing but time,” extends to rescue operations. Everything brought in must be packed out at the end of the operation. An abandoned flashlight battery can leach its chemicals and poison cave-adapted life forms, ultimately destroying the cave and its environment.

Personal Safety

Whether entering a cave for exploration or for rescue purposes, cavers should follow personal gear requirements specifically tailored to caving. Clothing should be appropriate to the environment. Caves can be wet, dry, dusty, cold, warm, or a combination of these. The wind that can exist in passages makes chill factor a significant consideration. Undergarments should provide the necessary thermal layers and be made of a fabric that remains warm when wet. Layering undergarments provides the most versatile system of clothing.

Many cavers wear protective suits with a rubberized, vinyl-coated, or Cordura outer layer. In very wet caves, it is not unusual to find cavers in wetsuits. Coveralls, or one-piece garments with no exterior straps or accessories, help prevent snagging in crawls or tight passages. Ventilation is an important consideration in accommodating the varying degrees of exertion required in caving.

A mountaineering type of helmet, with a nonelastic “three-point” chin strap that keeps it planted properly on the head, is a must. The helmet protects against impact with the hard and often sharp rock of cave ceilings and walls in tight or low passages and offers protection against falling rock. The helmet is also a convenient mounting platform for the required light source (Figure 46-6).

FIGURE 46-6 Typical helmet-mounted light.

(Courtesy Kris H. Green.)

It takes only one episode of trying to navigate in complete darkness underground to understand why every person entering a cave should carry no fewer than three light sources. Rescuers who are underground without functioning lights become additional cavers in need of rescue. Electric lights are preferred, but carbide lamps may also be used. At least two of these lights should be helmet-mountable for hands-free operation, each with sufficient “burn time” capacity or spare batteries to travel into and out of the cave. If carbide lamps are used, care should be taken when working close to patients, because it is easy in tight spots to forget that the light on the head is an open flame that can quickly burn anything with which it comes in contact. For this reason, most cave rescuers prefer electric lights.

Many cavers find gloves useful for both thermal insulation and protection against sharp rocks and sticky mud. Neoprene or rubberized gloves are popular choices, and scuba or sailing gloves offer durable protection. If the cave has vertical components, leather-palmed gloves are necessary for rope work. Ideally, a rescuer should carry different pairs of gloves for rope work and for negotiating a muddy passage.

Cave mud is slippery and adheres to everything. It makes walking and scrambling through a cave dangerous. Lug-soled boots provide the best traction, and stiff leather uppers help protect feet against sharp rocks. For small passages, or “crawlways,” a set of durable kneepads is a necessity, and many cavers use elbow pads as well.

Cavers, as any adventurers in a remote environment, should be self-sufficient and at least able to care for themselves for an extended period. This means being equipped with replacement batteries or carbide, potable water for drinking, food for energy, a basic first-aid kit, and extra insulation, such as thermal layers and a hat that can be worn under the helmet. In many caves, local ethics or regulations also require a “pee-bottle” and material for containing and removing solid waste. Cavers often store a folded trash bag in the suspension of their helmets to be used as an emergency shelter from wind and water, among other possibilities.

For the cave rescuer, the concept of self-reliance extends to being capable of caring for oneself, as well as a patient, for an extended period of time. Although the responsibility of patient care may be shared among several people, it takes planning to ensure that enough extra gear exists within the group so that the patient can be appropriately equipped and cared for.

Use a small, durable pack to carry extra gear. Because the gear will be alternately carried, pulled, pushed, and dragged through cave passages of different sizes, avoid excessively large packs with extra straps or external attachments because these can impede maneuverability.

Not all caves have vertical drops, but for those that do—or when in doubt—a lightweight seat and chest harness, descent device, and a rope-ascending system are essential. A rappelling device must withstand descent down a muddy or gritty rope. A brake bar rack, bobbin-type device, or sturdy figure-8 descender will do. Many devices designed for rock climbing are too lightweight to withstand these conditions repeatedly. In almost all in-cave drops, the caver will have to climb back up the rope. Thus an ascending system is essential. One or two 6-m (20-foot) sections of 25-mm (1-inch) tubular webbing come in handy for an extra step-up or to construct a quick belay or hand line.

Vertical caving is a highly specialized sport, and vertical cave rescue is even more specialized. The National Cave Rescue Commission offers courses in cave rescue, recommended for experienced vertical cavers.

Cave Navigation

Navigating through the cave environment can be disconcerting, particularly because of the three-dimensional nature of travel. Cave passage moves upward, downward, and side to side through the layers of the earth. Passage may overlap, cross, and twist, all without the benefit of sun, stars, or moss on the north sides of trees to provide directional clues. It is always best for several cavers (or cave rescuers) in a given party to be familiar with the cave and be responsible for navigation. If this is not possible, several options exist. The first, and best, is to use a cave map. Reading a cave map is an acquired skill that every cave rescuer should possess. In a pinch, cavers use navigational skills such as remembering landmarks, leaving temporary route markers (be sure to pick them up on the way out!), and using one wall of the cave as a source of consistency. Route markers are especially useful in cave rescue so that the rescuers can focus on the job at hand.

In an unfamiliar cave, keep track of prominent features so that you can find your way out. Passages often look different on the way out than they did on the way in. A small crawl that enters into a large room can be hard to find hours later when returning across that same room. One trick for finding one’s way out later is to get in the habit of turning around and looking at the passage as you enter into a different room, take a significant turn, or negotiate a climb. Rock cairns, light sticks, and flagging tape can be used as reminders. Another option is to leave pieces of reflective tape to mark the way and then remove them as you leave the cave.

During operations in a particularly complex cave, it may be necessary to enlist the help of local cavers to serve as guides for rescuers unfamiliar with the cave. This may be contrary to standard protocols that forbid nonteam members to participate in a search or rescue operation.

Cave Search

When the location of the rescue subject is unknown, a search will be required. Searching a cave is a potentially hazardous task and must be done meticulously and under good planning and management.¹³ A manager of a cave search uses the same basic skills as does an above-ground rescuer. Once the decision is made to begin an in-cave search, teams of cavers will be formed into task forces. Each search task force’s role is to look for, preserve, record, and recover clues that will lead to finding a missing person. The task force should consist of two or three members, one or more of whom should be familiar with basic search techniques, the cave being searched, and cave map reading. Members should be able to perform basic first aid, including patient assessment. In addition to personal caving gear discussed earlier, required equipment includes basic medical supplies, materials to mark passages, pencil and paper, food and liquid for the search subject, hypothermia protection, a map, and a compass. A marking system using colored flagging tape or other means should be established to mark side passages that have already been searched and to differentiate the best route in and out once a subject has been located.

Each search task force should obtain a briefing from command and then follow instructions as to where to search, how long to search, the probability of detection, how to preserve and record clues, how to report if a clue is found, and the debriefing procedures on return. If the search subject is found, the task force will assume the functions of an initial response task force. These functions are to determine whether the scene is safe, access the subject, treat the subject, consider possible courses of action (including walking the subject out if conditions allow), and then immediately notify command.

The report to command should include a full subject assessment, the task force’s recommendation for course of action, additional medical equipment or personnel needed, type of litter needed, obstacles to evacuation, any rigging that will be needed, and suggestions for action to be taken.

Basic Evacuation

On any cave rescue, each person entering the cave must have at least the minimum complement of personal gear, as described in the previous section. Beyond this, the amount of equipment used during a cave rescue is prodigious, particularly in a cave with complex terrain. Equipment and personnel are used nearly as quickly as they can be produced. Dry clothing, food, and water become valuable commodities, and extra supplies not normally used in cave exploration become necessities.

This last category, items not normally used in cave exploration, should be sourced, tested, and stored at the ready well in advance of being needed. Communications equipment, such as hard-wired field phones or cave radio systems, can be particularly difficult to find, as can experienced personnel to operate them. Other needs may include generators, warming tents, food services, and a command post.

Although most cave evacuations require litter transport, each individual situation should be evaluated carefully to determine whether a litter is really necessary. A properly stabilized “walking wounded” caver can be helped out of a cave in a short time and with little manpower. If that same individual is placed in a litter, however, the numbers of rescuers and hours to the hospital increase exponentially.

One crisp October day, cave rescuers in Georgia were dispatched to Pettijohn’s Cave on Pigeon Mountain to evacuate a fall victim some 30 minutes from the entrance. Samuel, a fit, experienced caver who was quite familiar with the cave, had taken a fall, experiencing a dislocated shoulder in the process.

Pettijohn’s Cave is normally considered a horizontal caving experience, but it also involves scrambling over breakdown block and negotiation of several short vertical drops. Although Samuel and his friends were quite familiar with the cave and he could easily negotiate the passage under normal circumstances, loss of the use of his arm would make it impossible for him to balance or climb on the difficult terrain. The pain of such a dislocation complicated matters greatly, and even a litter evacuation would prove to be a trying ordeal.

Terrain in the cave dictated that litter evacuation would require several roped systems, including an initial raise of 4.5 to 6 m (15 to 20 feet), a 30.5-m (100-foot) highline, and one to two more raises to lift the patient through and out the cave entrance. Although Samuel’s location was only an estimated 30-minute walk into the cave, the litter evacuation would easily encompass 6 hours and require numerous riggers and scads of equipment.

An experienced paramedic arrived and resolved the evacuation in short order by reducing the dislocation and immobilizing the limb securely to the patient’s body. Instead of requiring litter lowers and highlines, the rescuers were able to rig handlines, and Samuel walked out of the cave under his own power in a fraction of the time that the technical evacuation would have taken.

Not all cave rescue scenarios benefit from the fitness and ability of a caver such as Samuel or the presence of a skilled paramedic who can resolve a medical situation. If litter transport is deemed necessary, the next difficult decision is which litter (or litters) to use. On any given evacuation, this selection involves a fine balance of requirements. Maneuvering a bulky litter through narrow cave passages can be a challenging proposition. In larger caves, or where a vertical raise is required, basket litters are the best choice. Plastic-bottomed versions are preferable over steel and mesh versions because plastic allows the option of dragging the litter where necessary (Figure 46-7). In tighter caves, drag-sheet types of litters, such as the wraparound SKED, provide low profile and relative flexibility, but they are less comfortable or protective for the patient.

FIGURE 46-7 Plastic litter offers patient protection and slides easily through passage.

(Courtesy Kris H. Green.)

Occasionally, a cave is so restrictive that even the length of a flexible litter is problematic, and a short board, such as a KED or OSS, is the only alternative. It is not unheard of to begin the carry in a tight section of a cave using an OSS, then add a SKED once the passage opens up a bit, drop the SKED into a full basket litter for ease of carrying in a large walking passage, and then remove package layers all the way back to the OSS to negotiate a tight entrance passage.

When choosing a litter and patient packaging, duration of transport and patient comfort should be prime considerations. Natural positioning, pressure points, and temperature are all key concerns. Although rescuers are working up a sweat, the patient lying in the litter is stationary, unable to regulate his or her own comfort, and often extremely cold. Waste elimination may need to be provided for. Thermal layers are a necessity and include a sleeping bag, vapor barrier, and moisture barrier to keep the patient dry. A full-body vacuum mattress works well as padding, immobilizer, and insulator. The patient should also have adequate head and face protection and, if the transport route will become vertical at any point, a harness.

A reasonable first-aid kit for a cave rescue operation should contain writing materials for recording patient condition, basic medications, airway management tools, bandages, cervical collars, and splints. Sealing each item in plastic helps keep out cave grit, and the entire kit can be packaged in a large-mouthed bottle or other watertight, durable container. The kit should be able to fit into the caver’s own cave pack because it is much easier to carry one large pack than two smaller ones. The kit should target common injuries. More specialized supplies can be brought in as needed, but a comprehensive kit is not compatible with reasonable movement through the cave. See Box 46-1 for a minimal list of items to include in a cave rescue medic kit.

Because of extended times involved in reporting caving accidents and responding to and accessing injured cavers, most patients are either very stable or dead by the time medical help arrives. Advanced life support (ALS) skills and equipment are generally not required. This is fortunate because the effects of cave mud and water are not particularly friendly to medical electronics.

Sometimes a cave accident survivor is so badly injured that physicians or paramedics on scene choose serious drug intervention. At these times, electronic tools for monitoring vital signs can be extraordinarily valuable, but great care must be taken because the cave environment is ill-suited to the use of such devices. Even simple interventions such as intravenous (IV) infusions are problematic during cave rescues. In most cases, hanging a gravity-operated IV line is not an option, and positive-pressure infusion methods must be used. Furthermore, consideration must be given to methods for keeping the skin insertion point clean and care taken not to interrupt IV fluid flow while negotiating tight passageways.

Equipment—Vertical Evacuation

Ropes used for high-angle underground rescue are usually of the static kernmantle variety. Low stretch, abrasion resistance, and consistency of quality are considered key ingredients. Caves can be harsh and unforgiving, so for this purpose, the tougher the sheath, the better the rope. The toughest-sheathed rope is usually less pliable and forgiving than those more prone to abrasion, so skilled riggers should be used for the task. Rope length may vary, depending on the particular cave and the resources at hand. Ideally, rope lengths should be sufficient to negotiate each drop without tying knots to join ropes. Knot passes can add undesired complexity to the operation.

Most cave rescues involve negotiation of difficult passages, as well as raising the patient from below ground to the surface. This may be accomplished in many ways, but pulleys and haul systems are generally basic necessities.

Techniques used in high-angle rescue in the cave environment are quite similar to those used above ground, but cave rescue may be complicated by tight spaces, darkness, environmental conditions, and lack of alternative routes. Anchors will seem less available and less obvious to rescuers who are only experienced in rigging above ground.

Brake bar racks are most often preferred for lowering operations because of their variable friction advantages. In addition to these, adequate carabiners, anchor materials, and other hardware should be available for rigging. If multiple locations must be rigged for raising, lowering, or traversing, the best possible scenario is to have enough gear to rig each site individually. Having to de-rig a system, sort the gear, carry it past the proceeding litter, and re-rig another system is time consuming and can derail the entire operation. Even a small cave might require multiple sites rigged for safe patient extrication.

Prebagged packages of gear for specific common rigging tasks are useful. These include anchor webbing, ample carabiners, pulleys, Prusiks, belay devices, lowering devices, and rope grabs, as required, to set up one site per bag.

Logistics

Lack of easy communication, limited access, extended time, and difficulty in obtaining rest and nutrition for teams all contribute to the complexity of cave rescues.

Communication is essential to keep rescuers from becoming lost, to issue instructions, and to maintain the tempo of the operation. Various hard-wired field-phone systems are available for use in cave rescue, but generally only well-established teams have access to these. A relatively new development is availability of special low-frequency cave radios that can transmit voice through dense rock and soil. Without such systems, message runners are indispensable. A group of swift, agile, safety-minded, and well-trained cavers with waterproof notepads—and a method for keeping these volunteers rested and nourished—is invaluable.

A team of rescuers sent into a known location can take hours or most of a day to reach the patient. It is logistically impractical for these rescuers to carry sleeping bags and food to allow for rest and recovery before starting their work assignment. Keeping rescuers rested, fed, hydrated, and warm as they navigate a challenging cave rescue many hours away requires an incident management team that can predict the needs of the underground workers hours before they themselves realize the need.

Whether or not a communication system is available, establishment of a control point at or near the cave entrance is critical. Entrance control should be established as soon as rescuers arrive at the cave. A record of all personnel and equipment entering or leaving the cave should be documented in a log kept by a team member assigned to maintain entrance control. This log will become invaluable hours later in determining when teams should be replaced, verifying whether someone is still in the cave, and confirming who carried in what piece of missing vital gear.

The Incident Command System (see Chapter 36), or a modified version of it, provides the best framework for managing cave rescue personnel by performing required functions while maintaining a reasonable span of control. Generally, the functions required during a cave rescue are similar to those required during any other rescue, although the specific means of accomplishing those functions will vary.

There should always be one person in command of an operation. This is the foundation of creating accountability and organization, which are the keys to efficiency and safety. The incident commander assesses the incident, activates resources, determines the strategy, and approves the plan for the operation. This may be particularly challenging in jurisdictions in which the cave rescue experts are not the same individuals as the emergency response experts. Preplanning and relationships developed in advance are the best solutions for preventing problems in this area.

Other functions vital to success are planning, operations, logistics, and finance. The incident commander may have one or more assistants, or the commander may be responsible for several of these functions. Someone must plan strategies, supervise the operation, take care of the physical needs of the rescuers and required equipment, and track the resources used.

Cave Access

Gaining access to the patient is a matter of overcoming an array of obstructions inherent in the cave. Merely to move a few hundred feet through a cave might require rappelling, crawling on one’s belly, squeezing through cracks in the rocks, climbing over large rocks, swimming, and slithering through mud. Each of these is a more challenging experience when undertaken during a rescue while dragging a vast amount of equipment.

The total darkness of a cave imposes limits on any operation and its effect can be debilitating to some individuals. Even this simple matter can quickly become a major obstacle, particularly if noncavers are called on to assist in medical or other aspects of the operation. Psychological inhibitions, such as fear of the dark or confined spaces, can cause panic and severe dysfunctional behavior. In no case should a would-be rescuer ever be pushed beyond his or her comfort level.

Other factors inherent to the cave rescue operation include temperature variables, wetness, and restrictive cave passages. Certain large or weak people or bulky and heavy equipment might be physically incapable of passing through these tight spaces. These considerations exemplify why it is best for any medical or other rescue person who may eventually become involved in a cave rescue to gain knowledge and experience in advance.

If the cave rescue requires raising or lowering a patient or traversing the patient over horizontal rope lines, people skilled in cave rigging should be responsible for building the systems. Rigging in caves is an art because of anchoring difficulties, directional changes, tight squeezes, and minimal working surface. Details on cave rigging and professional training can be acquired through the National Cave Rescue Commission, a nonprofit organization that teaches courses in cave rescue techniques and management.

Many vertical drops in caves are overhung at the top, preventing the rescuer access to a wall while descending and ascending the rope or moving the patient. In cases in which the roped drop has the rope running against a wall, it can be advantageous to place anchors at points throughout the length of the drop. This “re-belay” method allows multiple people to ascend or descend simultaneously, lessens rope wear points, and provides the added safety of having a shorter rope length for each anchor to protect. Practice at crossing re-belays is essential before attempting to enter a cave thus rigged. The caver must be able to effectively transfer from one free-hanging rope to another while hanging in midair. This is easy to do with the correct equipment setup and practice, but not so easy when the technique is tried for the first time underground on the way to a medical emergency.

Usually, single-rope techniques are used, especially where a long free-hanging drop is involved. This means that just one rope is put over the side for the rescuer to ascend or descend. The use of an additional belay line not only requires additional people but also might prove more hazardous if the two lines become entangled. The moving belay line also has the potential to dislodge rocks onto the caver below.

In the United States, the most common cave-ascending systems are the frog system, Mitchell system, and various renditions of the ropewalker system. These are all efficient means of ascending and can easily be mastered with practice. The frog system requires more climbing effort but is easier to use when ascending past re-belays in the system.

It is imperative that an ascending system be fitted to the user. Some rigs work best for tall, lean frames, and others work best for heavier body types. All rescue team members entering a vertical cave should have their own personally fitted rope-climbing system and must have practiced climbing in that system in a safe practice area.

Large holes or boulder slopes inside the cave may best be negotiated by using a highline traverse. Proper setup of highlines can be a time- and equipment-intensive process, but it can shave away hours of litter movement time by passing above difficult cave terrain that otherwise would present many challenges for a litter carried by hand. Use of a highline is most practical when it is known in advance that there will be sufficient time for rigging. The decision to take the time to rig a highline traverse should be made based on three factors: the time it will take to move the patient to the obstacle you want to traverse, the time necessary to rig the highline, and the time that will be saved by using the highline to move the patient over the obstacle.

Environmental Hazards

One often-overlooked hazard to cavers is the ambient atmosphere. Most caves in the United States breathe naturally, either from changes in barometric pressure or from the chimney effect of multiple entrances. When this airflow is interrupted, limited, or polluted in some way, the resulting air can become hazardous to entrants.

The most basic type of atmospheric hazard is lack of oxygen. Some caves have small rooms with so little airflow that a few cavers can quickly consume most of the oxygen. While frightening, this type of atmospheric hazard is usually quickly recognized as open flame headlamps sputter or cavers become short of breath. Once recognized, the hazard can be mitigated by avoiding panic, controlling air consumption, and relocating to a friendlier part of the cave.

Another type of atmospheric hazard involves buildup of gases such as carbon monoxide, carbon dioxide, methane, and hydrogen sulfide. This can happen as a result of natural metabolism of organic material or through external influences. Instances of gasoline seeping into caves from underground storage tanks have been recorded. If poor air quality is suspected, use of an air-monitoring device is essential. It is possible to enter a cave containing high levels of unhealthy gases, but only with appropriate caution. In such cases, it is advisable to solicit participation of the local hazardous materials emergency response team.

With the assistance of a hazardous materials or confined space rescue team, “bad air” in caves can be mitigated in several ways. One way is to release compressed air into the cave, forcing good air in and bad air out. Success of this method is limited, and because of the massive amounts of air in a cave, this approach is slow at best. If this method is used, entrants should carry an air monitor because pockets of bad air may remain trapped in parts of the cave. The concept of simply releasing oxygen into the cave is a nice idea, but impractical in all but the smallest of spaces. Exhaust fans offer a reasonable method, although care must be taken to prevent generator exhaust from entering the cave.

If necessary, rescuers can be equipped for entry with surface-supplied air with bailout bottles, self-contained breathing apparatus, or rebreathers. Each of these has advantages and disadvantages, but all are difficult to manage in the cave environment and thus should be avoided if possible. Pre-event training and practice in the safe use of any of this equipment are imperative before entering an atmosphere that is hazardous for breathing.

In any rescue situation, atmospheric hazards should be considered before entering a cave. If such hazards are suspected, no rescuer should enter the environment without an appropriate filter mask and other personal protective equipment.

Other environmental hazards posed by caves may be more readily recognized and should also be considered before any rescue. As discussed earlier, water and caves are usually closely associated. Created by water, caves are a natural deposit for overflow or drainage from a variety of sources. This makes caves particularly prone to flooding with little or no warning. A recreational caver (Figure 46-8) or rescuer caught in a flooding cave is in mortal danger.

FIGURE 46-8 Recreational caver in wet pit.

(Courtesy Kris H. Green.)

Flooding is usually associated with heavy rains, which can cause diffuse seepage over a large area of the cave or a high flow into sinkholes. Occasionally, sinking streams can carry floodwater. In some parts of the world, entire rivers disappear underground, flow through caves, and resurface miles away. A flood crest from many miles upstream can pass through these caves without warning.

Flood-prone caves are generally identifiable by their makeup. Cave walls coated with thick mud can be an indication that flooding is not unusual in that section of the cave, and extra caution is warranted. Bedrock cave walls with gravel deposits at key points in the cave and debris lodged in the ceiling can also be warning signs.

Becoming trapped in a flooding cave is not desirable, but it can be survivable. If possible, find a high point in a wide passage, downstream of any major constriction, and wait out the flood. It is also possible, with enough advance warning, to remove a sediment dam downstream that may otherwise cause water to back up into your “safety zone.” It is seldom wise to attempt to swim, either upstream or down.

For a rescuer called to assist cavers trapped in a flooded cave, entering the torrent is not wise. If the location of the trapped persons is known, it may be possible to use (or make) another entrance from which to evacuate them. Knowledgeable local cavers can be extremely valuable in this instance.

If entry into a flooded cave through the main entrance is absolutely necessary, it is imperative that the water level be controlled before entry. Methods of accomplishing this goal vary depending on the situation. Often, it may be enough to simply wait out the flood and let the water level subside naturally. If the water level is still on the rise, however, or if the source remains constant, additional measures may be warranted. Keep in mind that water is a powerful force, and any plan should be engineered by professionals.

One of the simplest diversion methods is to broaden the flood crest so that less of it flows into the cave. Water can be diverted using sandbags, hay bales, or dirt or by digging channels. If this is not possible or feasible, one may be able to lower the water level by digging through debris downstream, thereby expediting the exit. Pumping is also an option, although the hazards inherent in this method should be evaluated closely beforehand. Pumps run on fuel or electricity. Fumes from fuel-driven pumps and generators have entered caves and poisoned the air of the cavers waiting for rescue. Electrical power in a flooded cave situation adds a high risk for electrocution to the operation. Failure of the pumps after rescuers enter a cave can trap additional people if the water rises again.

Entering a flooded cave with scuba equipment is a dangerous, last-resort method that should be attempted only by certified cave divers. A scuba entry may be justified if cavers are known to have been entrapped for an extended period of time, if there is a known medical emergency, or if the cave is completely flooded. In these cases, it may be advisable for certified cave divers to enter and assess the condition of entrapped people, transport survival supplies, or provide medical assistance. Even certified cave divers require additional skills and equipment to enter a recently flooded or sumped cave passage, compared with the typical sport cave dive. A flooded cave may have little to no visibility, currents, and debris blocking the passage. Only in the most dire circumstances is it justified to attempt to transport a patient through a flooded passage.

At a minimum, a scuba entry requires two to three divers, as well as a backup diver. Diving is gear intensive and requires an air compressor, extra tanks, 110-volt electricity to charge dive lights, underwater communications equipment, waterproof bags, full face masks for subjects, water rescue suits, underwater lights, transport cases, and surface personnel to assist with transporting equipment.

Medical Hazards

The most common cave-acquired disease is histoplasmosis, which is caused by Histoplasma capsulatum, a dimorphic fungus present worldwide but especially prevalent in the Ohio and Mississippi River valleys of the United States.¹ It is associated with bird, and especially bat, guano (Figure 46-9).¹² At a national caving convention in 1994, at least 18 people contracted symptomatic histoplasmosis, with an attack rate of greater than 70% for attendees going into two local caves.¹ A follow-up skin test survey found that 60% of one group of cavers showed evidence of Histoplasma capsulatum exposure.¹

FIGURE 46-9 Caver in guano.

(Courtesy Peter Febbroriello.)

Cavers get histoplasmosis by breathing dust from affected parts of the cave. Incubation is 2 to 3 weeks. Most primary cases are not even recognized, because they resemble a flulike illness with fevers, headaches, and cough.²¹ Persons with significant illness demonstrate patchy lung infiltrates, which may calcify, and hilar lymphadenopathy. Some cases progress to cavitation or dissemination. Detection of urinary antigen is the mainstay of diagnosis. In most cases treatment is not necessary. If symptoms last longer than a month, treatment is indicated with itraconazole or other azole drugs or, in cases of dissemination, amphotericin B. Patients may require 3 to 6 months of treatment.⁹

Leptospirosis has been reported on caving expeditions to tropical climes but is probably a risk in temperate regions as well.^5,^6,^17,²² Transmission occurs when water contaminated by urine from infected animals comes into contact with mucous membranes, the conjunctivae, or abraded skin.¹⁸ Cavers often crawl through small passages in the rock to explore what lies beyond, sometimes greatly abrading the skin, especially in hot humid caves where protective clothing may be minimal. Immersion may increase the risk.⁴ Water that has percolated through carbonate rocks in which most caves form will have a higher pH, which favors survival of leptospires.¹¹

Leptospirosis manifests with fevers, chills, myalgias, and headache after a 1- to 4-week incubation.¹⁶ More specific findings are conjunctivitis, proteinuria, and hematuria. It is most commonly diagnosed with serum microscopic agglutination titers (MAT). The diagnosis is confirmed by a fourfold rise in MAT, but is suggested by a titer of 1 : 800 with appropriate exposure and symptoms. Treatment is IV penicillin or ceftriaxone for severe cases and oral doxycycline for mild cases. It can be prevented with 200 mg of weekly doxycycline.²³

The Centers for Disease Control and Prevention recommend rabies vaccination for “spelunkers.” This dates from a concern about two cases of rabies in cavers that were attributed to aerosol transmission. These two people separately visited Frio Cave in Texas, where millions of bats congregate, and developed rabies soon thereafter. Subsequent research demonstrated the presence of rabies virus in the air of Frio Cave, presumably from bat respiratory secretions.^2,²⁴ Transmission to animals exposed only to airborne virus has since been demonstrated in the laboratory and in Frio Cave.^7,⁸ Therefore in the context of massive bat maternity colonies, aerosol transmission of rabies appears possible.

Still, the matter is not so simple. In both cases, there was a more probable cause for rabies than aerosol transmission.¹⁰ In the first case, the caver was employed in a rabies laboratory and worked inoculating bats with rabies virus.¹⁴ The second patient denied being bitten by a bat, but was noted to have a bleeding lesion on the face while exiting Frio Cave.^10,¹⁵

So what are cavers to do? Certainly, anyone doing bat research needs to be vaccinated against rabies and to check titers routinely. Anyone working in caves like Frio needs appropriate masks to filter the hazardous atmosphere, of which rabies is just one component. It is questionable whether the sport caver really has any business at all roaming in a bat maternity colony.³ Decades of exposure have not resulted in further documented cases of cavers contracting rabies. Although some persons have called for vaccination of all cave explorers, the opinion is not unanimous.³ Each caver needs to decide on the level of risk and act accordingly.

Patient Care

As with many remote accidents, the time it takes to report, respond to, and access a caving accident usually means that the person, if alive, is relatively stable. Although this generalization has exceptions, the treatment issues faced by most rescuers are related to extended transportation times.

Data compiled for American Caving Accidents indicate that the leading cause of caving injury is falls, and that hypothermia, fractures, and head injuries top the list of complaints.^19,²⁰ Unfortunately, with significant falls, spinal injury must be contemplated, which compounds the transportation challenge. The approach to medical care should be similar to any other medical situation, with a notable difference: the patient has suffered an acute injury but will be confined for an extended period. Care, then, will be a combination of acute emergency responses adapted for a patient who is, for all practical purposes, bedridden.

Once the patient has been stabilized and packaged, the assessment process should continue throughout the evacuation. It is best if one medical person stays with and monitors the patient throughout the evacuation (Figure 46-10). The ideal medic is a strong caver with good single-rope technique skills and at least paramedic training. By constantly staying with the patient, the medic is best placed to observe changes. The medic will need to know the complete patient history and clinical evolution while en route in order to make decisions that affect the extrication effort, such as needs for urgency and patient orientation. Although other evacuation personnel may cycle through the rescue, the constant presence of the medic is reassuring to the patient. Because the medic may need to spend many hours with the patient, he or she should not take part in the strenuous activity of litter handling.