The fascination of diving always involves a certain level of risk. Even experienced divers who have already been pursuing this sport for decades, either in their spare time or on a professional basis, and have clocked up untold dives in their logbooks, can become victims of a diving accident at any time.
If an emergency arises under water, the diving partners on the one hand and the alerted rescuers on the other are faced with a challenging exceptional situation. And in such a scenario, literally every second counts after the emergency ascent and rescue of the diver in distress – extensive measures have to be taken immediately in order to prevent damage to health, or even save the casualty’s life, as the case may be.
However, in many operations of this type the rescue missions are more difficult by weather and environmental conditions such as wetness, wind, temperature, and rough terrain, as a result of which the demands made of staff and medical equipment are particularly high in such emergencies. The GS corpuls company from Kaufering in Upper Bavaria has been developing innovative patient monitoring systems with an integrated defibrillator and mechanical chest compression devices for over 35 years now. In collaboration with users (including EMS personnel, physicians, and hyperbaric chamber centers) their requests and ideas are integrated into the development process, as a result of which all items of equipment, for example, have a high degree of protection against dust and spraywater so they are ideal for outdoor use.
Based on a case study, there follows a description of how a diver in distress was rescued successfully. Accidents of this kind take place several times a year, not only in Germany.
One cloudy Saturday morning in early summer two experienced divers (63 and 48 years old) set off to explore a steep face in a Bavarian lake. The face suddenly comes to a stop and then goes down to a depth of about 90 meters. In recent years there have been over 50 diving accidents in this area, 18 of them ended deadly. Back in 2008 the basic requirements for diving expeditions were tightened up considerably on account of high accident rates: the maximum diving depth with compressed air was restricted to 40 meters; from a depth of 20 meters it is necessary to use apparatus that is fully compatible with cold water (including two breathing regulators that can be turned off separately); and in winter, diving generally is prohibited.
09:04 Following a thorough check of equipment the dive begins. After about half an hour under water, the 63 year-old suddenly signals to his buddy at a depth of about 13 meters that he is having problems with his air supply and shortly after that he is in danger of sinking. His colleague holds him tightly grasping his jacket and immediately starts the emergency ascent. When the two reach the surface of the water the distressed diver loses consciousness. Bystanders notice the emergency and alert members of the nearby water rescue station, who are just about to go on duty.
09:36 Until the arrival of the rescue boat the younger of the two scuba divers attempts to keep his friend’s face above the water and, even at that early stage, ventilates him several times. Meanwhile, the rescue control center triggers a general alert (local fire department, first responder unit, two ambulances, two helicopters with emergency physicians, command vehicle together with a head of operations, other water rescue units, and police). The two divers are brought to land in the rescue boat without delay. The resuscitation procedure that began immediately is continued there. Using a special ventilation valve (demand valve) the artificial mask ventilation reaches a very high oxygen saturation level of nearly 100%, which is very important especially in diving and drowning accidents. As a result, the nitrogen bubbles that have formed in the blood cannot become larger and at the same time the vital organs are supplied with Oxygen.
09:44 The first defibrillation is administered to the distressed diver about eight minutes after rescue from the water, using the corpuls1 defibrillator of the first responder who has since arrived. The institution is a voluntary one whose members provide qualified first aid at the scene
and bridge the waiting time until EMS arrives.
09:47 The second diver is responsive but has unstable circulation and complains of the typical symptoms after an emergency ascent. At the water rescue station he is also supplied with oxygen and given psychological care. Meanwhile the first emergency doctor has arrived at the resuscitation procedure and he starts administering medication and other measures while his driver fits the corpuls cpr mechanical chest compression device.
By administering chest compression to a patient requiring resuscitation the absent pumping capacity of the heart a minimum circulation is sustained and the oxygen in the blood reaches the vital organs. With mouth-to-mouth or mouth-to-nose ventilation the blood is enriched with oxygen again – albeit at a much lower concentration because the air administered is air exhaled by the responder. With defibrillation, on the other hand, an attempt is made to put the heart’s pacemaker system, which has gotten out of control and is normally responsible for contraction of the cardiac muscle and hence the pumping function, back into a controlled rhythm by administering a systematic surge of current. If these measures are not taken, the patient’s chance of survival decreases by about 10 percent each minute.
Chest compression with a pressure depth of about five to a maximum of six centimeters (according to ERC) at an ideal rate of about 100 to 120 compressions per minute tires out even the best-trained first-aider. As a result, pressure depth and frequency decrease and the efficiency of cardiopulmonary resuscitation (CPR) is significantly reduced. The new, mechanical chest compression device corpuls cpr ensures absolute consistency and hence a constant bloodflow. On account of its articulation and adjustability for height it is also possible to treat relatively corpulent patients, for example. In addition – depending on the resuscitation mode that has been set – the device automatically attracts the user’s attention if the procedure is due for a ventilation pause.
In any manual resuscitation there are moments when chest compression has to be interrupted. Such situations include, for example, transfer of the patient to a wheeled stretcher, rough terrain when transporting the patient to the ambulance, and, for safety reasons, the journey to the hospital. Once it has been fitted, the corpuls cpr, even in these situations continues
chest compression consistently, which significantly increases the effectiveness of the resuscitation procedure.
In the meantime the two ambulances and the rescue helicopters have also arrived. The moderately injured diving partner is examined by emergency paramedics, stabilized, and then flown to a nearby accident clinic with its own in-house hyperbaric chamber. He has symptoms typical of a diving accident, such as severe itching, depression of consciousness, and respiratory distress.
Meanwhile, the diver requiring resuscitation is taken to the emergency ambulance on the wheeled stretcher, together with the corpuls cpr, and is already being monitored by a corpuls3 patient monitor with an integrated defibrillator. On account of its modular design the device can be split up into three components, which conduct wireless communication with each other. The monitor module displays the vital parameters (such as oxygen saturation and pulse rate) and ECG traces and is also the system’s user interface.
The patient box remains directly with the patient, collects the ECG data and measurements of the various sensors, and transmits them to the monitor live. The defibrillator / pacemaker module can be used with conventional “paddles” or adhesive pads. For example, if the ground is wet a lifesaving shock can also be triggered from a safe distance. In addition, the emergency doctor has the patient’s measurements and ECG traces within view at all times and can react quickly to any changes.
After another 20 minutes of ongoing resuscitation with multiple defibrillations in the stationary ambulance, the emergency doctors succeed in restoring the man’s heartbeat. When his circulation has stabilized sufficiently, the distressed diver is transferred to the helicopter and also flown to the Trauma Center.
There the notified specialists are already waiting in the prepared trauma emergency room. They put the patient into an induced coma and continue to stabilize his condition. The resuscitation device, corpuls cpr, together with a board, is for the most part radiolucent so it can, for example, be easily used during procedures in the cardiac cath-lab without influencing the angiography (imaging of the heart vessels). Following management in the trauma emergency room the diving casualty is taken directly to the hyperbaric chamber.
On account of the emergency ascent it was not possible to comply with the decompression time required to enable the nitrogen that had accumulated in tissue to dissolve. During hyperbaric oxygen therapy (HBO), dives are simulated by raising the ambient pressure in the chamber (usually up to 300kPa). Ventilation is performed with pure oxygen, which under these conditions is dissolved in the blood to a maximum extent so the patient’s tissue has an increased supply of oxygen available and the nitrogen bubbles become smaller or can be exhaled. Before the HBO chamber procedure commences, both eardrums of the comatose patient are perforated because on account of his unconsciousness he is unable to perform pressure compensation on his own. The small holes close again of their own accord after a few days.
The diving casualty is then treated in compliance with the standardized US Navy Table 6 (USN TT6): after the relatively rapid descent to 18 meters (1.8 bar gauge pressure) multiple alternating oxygen and air breathing phases follow. After about 95 minutes there is an “ascent” to 9 meters and more breathing phases, with and without an increased oxygen fraction in the gas mix.
Throughout the entire hyperbaric treatment the diving casualty is monitored by a corpuls3 hyperbaric. This device version was specially modified for use in HBO chambers, as a result of which even at different pressures reliable values can be measured and, in an emergency, safe defibrillation procedures can be performed. Use of the corpuls3 hyperbaric was certified by DNV GL SE for an ambient pressure of up to 3 barg.
The diving casualty remained in the intensive care unit of the accident clinic for another five days. After another four treatments in the hyperbaric chamber the symptoms had completely disappeared and the 63 year-old man was brought out of his coma. On account of swift, level-headed action on the part of his “buddy”, expert first aid, systematic use of reliable, rugged medical equipment, and early hyperbaric oxygen therapy, his life was saved and permanent damage was avoided.