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Introduction
This section is focused on the individual employee's decision making and actions in accident prevention and response. For the purpose of this section, the employer's electrical system design, engineering, and management processes to operate and maintain the system are assumed to enable the employee's actions in a safe work environment.
Accident Prevention
No matter how carefully a system is engineered, no matter how carefully employees perform their tasks, and no matter how well trained employees are in the recognition and avoidance of hazards, accidents still happen. This section provides a general approach that may be employed to reduce the number and severity of accidents. Four basic steps-employee responsibility, safe installations, safe work practices, and employee training-combine to create the type of safe work environment that should be the goal of every facility.
Individual Responsibility
The person most responsible for your own personal safety is you. No set of regulations, rules, or procedures can ever replace common sense in the workplace. This statement should not be construed to mean an employer has no responsibility to provide the safest practical work environment, nor does it mean that the injured person is "at fault" in a legal sense. Determining fault for accidents is, in part, a legal problem and is beyond the scope of this handbook.
Time after time, accident investigations reveal that the injured person was the last link in the chain. If the injured person had only been wearing appropriate safety equipment or following proper procedures, or if he or she had only checked one last time, the accident never would have occurred.
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TABLE 1: Employees Safety Behavior
• Determine the nature and extent of hazards before starting a job.
• Each employee should be satisfied that conditions are safe before beginning work on any job or any part of a job.
• All employees should be thoroughly familiar with and should consistently use the work procedures and the safety equipment required for the performance of the job at hand.
• While working, each employee should consider the effects of each step and do nothing that might endanger themselves or others.
• Each employee should be thoroughly familiar with emergency procedures.
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Table 1 lists five behavioral approaches that will help to improve the safety of all employees. To make certain employees have both the responsibility and the authority to carry out the five steps listed in Table 1, employers should adopt a policy similar to the one listed in Table 2. Simply putting such a statement in a safety handbook is insufficient. An employer must believe in this principle and must "put teeth into it." Such a credo provides the absolute maximum in individual employee responsibility and authority and will maximize the safety performance of the organization.
TABLE 2 Recommended Safety Credo:
If it cannot be done safely, it need not be done!
Installation Safety
Design. Proper design of electrical systems is composed of three parts-selection, installation, and calibration.
Selection. Electric equipment should be selected and applied conservatively. That is, maximum ratings must be well in excess of the quantities to which they will be exposed in the power system. To help with this, manufacturing organizations such as the National Electrical Manufacturers association (NEMA) have established ratings for equipment that ensure member companies manufacture only the highest-quality equipment. Equipment is tested per manufacturer's procedures by independent laboratories such as the Underwriters Laboratories (UL). Equipment that is rated and labeled by such organizations should be used in electrical systems to help ensure safety. OSHA, NEC, and NeSC requirements should be considered as minimum criteria for safe selection. With increasing cost consciousness, many companies are opting for the installation of recycled rather than brand- new equipment.
While the selection and use of such equipment can be a financial advantage, at least three criteria should be considered in the purchase:
1. even though used, the equipment should have been originally manufactured by a reputable, professional firm.
2. The recycled equipment should be thoroughly reconditioned by a professional recycling company such as those represented by the professional electrical apparatus recyclers League.
3. Engineering studies such as short-circuit analysis and coordination studies must be performed to ascertain that the recycled equipment has adequate ratings for the sys tem in which it is being placed. Since the system short-circuit values may change with time, this requirement is true even if the recycled equipment is a direct replacement for the previous equipment.
• Installation. Equipment should be installed in a safe and sensible manner. Adequate work spaces for safety clearance should be allowed, safety barriers should be provided when necessary, and electrical installations should never be mixed with areas that are used for general public access.
• Calibration. Equipment always should be properly calibrated. For example, protective devices should be calibrated so that they will operate for the minimum abnormal system condition. Equipment that is improperly calibrated can result in accidents as though the equipment had been improperly selected to begin with. Calibration is also a two- step process:
1. Proper engineering should be performed by professional engineers to ensure that the selected calibration settings are suitable for the application. The starting point for such a system is in the performance of an appropriate suite of power system studies, described later in the section.
2. Proper testing and physical setting of the devices should be carried out to ensure that the equipment is capable of performing when called upon. Such settings should be executed by professional technicians who are certified to perform this work.
Organizations such as the International Electrical Testing Association (NETA) have been formed to ensure quality control on the education and performance of electrical technicians.
Electrical Protective Devices. Protective devices such as circuit breakers, fuses, and switches must be capable of interrupting the currents to which they will be subjected. The National electrical Code has numerous passages that require proper sizing of protective devices.
Maintenance. Improperly maintained equipment is hazardous. For example, circuit breakers can explode violently if not properly maintained. Equipment should be periodically inspected and tested. If deficiencies are observed, the equipment must be repaired, adjusted, or replaced as required. Properly trained and certified technicians and mechanics should be used for such work. As mentioned earlier, national organizations such as NETA can be used to provide qualified personnel.
Operating Schemes. Many personal injury accidents could be prevented if systems were all designed for safe operating procedures. The following are some of the key design concepts that should be used for any new or refurbished electrical system:
1. arc-resistant switchgear should be employed. In addition to reducing the possibility of electrical arcs and resulting blasts, arc-resistant switchgear is designed to contain the blast and blast products. Such switchgear also has pressure relief systems that will redirect the release of arc and blast products and energy in directions that are safe for workers.
2. remote operating controls should be used for all circuit breakers, switches, and other such control devices. This relatively simple and inexpensive design technique allows workers to operate equipment while stationed remotely from the possible results of failure. Whether supervisory control systems or simple remotely placed, hard-wired control switches are used, the distance will allow the workers to operate the equipment in relative safety.
3. Control panels should be designed with protective barriers to prevent shock hazard and contain arcs and arc products. For example, many industrial control panels are fed via 480 v circuit breakers. This breaker, in turn, feeds a step-down transformer. The control voltage output of the transformer feeds the various control circuits throughout the panel.
If the 480 v portions of the circuit are designed with appropriate protective covers, workers in the panel need to protect themselves only from the electrical hazards presented by the 120 v circuits.
Power System Studies
Power system studies are engineering procedures that must be performed. There are three distinct times in the life of a power system when such studies should be performed:
1. During the initial design of the system to ensure that all selected equipment will perform properly during the day-to-day operation of the facility.
2. Any time a significant change occurs such as replacement of an existing piece of equipment or addition of new equipment or circuits.
3. at intervals during the life of the system to identify any possible changes that may have occurred externally. For example, electric utility supplies are changing constantly. Such changes can have a profound effect on the short-circuit currents and normal operating voltage levels.
The studies described in this section should be considered safety-related procedures. If they are not performed, equipment may be improperly applied and can fail, putting personnel at risk.
ANSI/IEEE standard Std- 399 (Recommended Practice for Industrial and Commercial Power Systems) identifies 11 recommended power systems studies. Of these 11, the short-circuit analysis and protective device coordination study are among the most critical with respect to electrical safety. As described later in this section, such studies are required by some industry standards.
The following paragraphs briefly describe these studies and provide basic information about their importance and implementation. The reader is referred to the most recent edition of ANSI/IEEE standard Std- 399 for details. Also note that these procedures are safety- related; they should be performed only by engineers and technicians with the education and experience to do them correctly.
Load Flow Analysis. This type of study determines the voltage, current, reactive power, active power, and power factor in an operating power system. It is performed using computer software and can be set up to analyze contingencies of any type. Such studies are used to size and select equipment and will alert system operators to possible hazardous or poor operating conditions.
Stability Analysis. Stability in a power system is defined as either transient or steady state.
Steady state stability is the ability of a power system to maintain synchronism among machines within the system following relatively slow load changes. Transient stability is the ability to maintain synchronism after short- term events occur, such as switching and short circuits.
Stability studies are safety- related in that they will allow the power system operator to continue safe operation even when the system is exposed to abnormal or excessive events.
Motor-Starting Analysis. When large motors are started, the high current surges and voltage dips can cause malfunction or failure of other system components. A motor- starting analysis uses a computer program to model the behavior of the system when the motor starts. This can be used to size the power system equipment to prevent outages, and the hazards associated with them will be reduced or eliminated.
Harmonic Analysis. Harmonics and other types of power quality problems can cause pre mature equipment failure, malfunctions, and other types of hazardous conditions. Such failures can include heating and failure of rotating machinery and power system capacitors and their associated hazards. A harmonic analysis is performed to pinpoint the sources of harmonic distortion and to determine the solutions to such problems.
Switching Transients Analysis. When certain loads are switched and/or when switches are malfunctioning, failures can occur, which can put employees at risk. A switching transients study determines the magnitude of such transients and allows the system engineers to develop solutions.
Reliability Analysis. Reliability is usually expressed as the frequency of interruptions and expected number of interruptions in a year of system operation. When properly applied, the results of a reliability study can be used to make sure the system operates as continuously as possible. This means that workers will not be exposed to the hazards of working on the system to repair it.
Cable Ampacity Analysis. Cable ampacity studies determine the ampacity (current- carrying capacity) of power cables in the power system. Properly selecting power cables and sizing them will help to minimize unexpected failures.
Ground Mat Analysis. The subject of system grounding is covered in detail in Section 5.
One of the most important pieces of equipment in the grounding system is the ground mat.
A properly designed and installed ground mat will reduce step and touch voltages and provide a much safer environment for the worker. According to IEEE standard std- 399, at least five factors need to be considered in the ground mat analysis:
1. fault current magnitude and duration
2. geometry of the grounding system
3. soil resistivity
4. probability of contact
5. Humans factors such as (a) Body resistance; (b) standard assumptions on physical conditions of the individual
Short-Circuit Analysis and Protective Device Coordination. A short-circuit study deter mines the magnitude of the currents that flow for faults placed at various buses throughout the power system. This information is used to determine interrupting requirements for fuses and circuit breakers and to set trip points for the overcurrent devices.
A coordination study is performed to make certain the overcurrent devices in a system will trip selectively. Selective tripping means that only the nearest upstream device to the short circuit trips to clear the circuit.
The two studies, taken together, are used to properly select and calibrate the protective devices used in the power system. The information that they provide is used for the following purposes:
• fuses and circuit breakers are selected so that they are capable of interrupting the maxi mum fault current that will flow through them.
• instantaneous elements are selected so that they will respond (or in some cases not respond) to the short-circuit currents that will flow through them.
• time curves and instantaneous settings are selected so that the nearest upstream device to the short circuit is the one that operates to clear the fault.
• protective devices are selected so that the short circuit is cleared in a minimum amount of time with as little collateral damage as possible.
• protective devices are selected so that fault currents that flow through cables and trans formers will not cause thermal or mechanical damage to those pieces of equipment.
Each of these points is critical to the safe and economical operation of a power sys tem. For example, if circuit breakers or fuses are incapable of interrupting fault currents, they may explode violently, injuring personnel in the area. If the wrong protective device operates, a "small" outage may expand to include an entire plant. If a transformer over load relay is too slow, the transformer may be damaged by excessive temperature rise.
The only way that such malfunctions can be avoided is to perform a short-circuit analysis and a coordination study and then to select and set protective devices according to their results.
The NEC is the principal source of regulation in the area of electrical installation and design requirements for industrial and commercial facilities. The NEC has several sections that are pertinent. Table 3 reproduces a few of these sections.
In addition, ANSI/NFPA 70B, Electrical Equipment Maintenance, also has a section that applies. This is reproduced in Table 4. The only way to comply with these requirements is to ensure that a short-circuit analysis and a coordination study are performed for the power system.
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TABLE 3 NEC 70-2011 requirements for Short-Circuit analyses and Coordination Studies
Location in NEC ---- Item
[ Definitions
article 110
Article 240
]
[
Interrupting rating. The highest current at rated voltage that a device is identified to interrupt under standard test conditions.
110-9. Interrupting rating. Equipment intended to interrupt current at fault levels shall have an interrupting rating not less than the nominal circuit voltage and the current that is available at the line terminals of the equipment.
Equipment intended to break current at other than fault levels shall have an interrupting rating at nominal circuit voltage not less than the current that must be interrupted.
110- 10. Circuit Impedance, Short-Circuit Current ratings, and Other Characteristics. The over current protective devices, the total impedance, the equipment short- circuit current ratings, and other characteristics of the circuit to be protected shall be selected and coordinated to permit the circuit- protective devices used to clear a fault to do so without extensive damage to the electrical equipment of the circuit. This fault shall be assumed to be either between two or more circuit conductors, or between any circuit conductor and the equipment grounding conductor(s) permitted in 250.118. Listed equipment applied in accordance with their listing shall be considered to meet the requirements of this section.
240-12. Electrical System Coordination. Where an orderly shutdown is required to minimize hazard(s) to personnel and equipment, a system of coordination based on the following two conditions shall be permitted:
(1) Coordinated short-circuit protection
(2) Overload indication based on monitoring systems or devices.
Informational note: The monitoring system may cause the condition to go to alarm, allowing corrective action or an orderly shutdown, thereby minimizing personnel hazard and equipment damage.
]
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TABLE 4 ANSI/NFPA 70B 2010 requirements for Short-Circuit analyses and Coordination Studies
[
ANSI/NFPA 70B
paragraph 8.4.3
para 8.4.3.1
]
[
Item
An up-to-date short-circuit and coordination study is essential for the safety of personnel and equipment. As a function of the study, the momentary and interrupting rating requirements of the protective devices should be analyzed and verification made that the circuit breaker or fuse will safely interrupt a fault during fault conditions.
Additionally, the study should provide the application of the protective device to realize minimum equipment damage and the least disturbance to the system in the event of a fault by properly clearing downstream devices nearest to the point of a fault.
]
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Few would deny that such studies should be performed during the design phase of an electrical power system. But how about later, as the system ages? Several things happen to require the performance and/or reevaluation of these studies for an existing system:
• Electric utilities constantly add capacity. Your utility may have had a 200,000- kilo-volt-ampere (kva) fault capacity when the plant was new 20 years ago. Now, however, the utility's capacity may have doubled or even tripled. Such changes can cause fault duties to rise above the ratings of marginal interrupting equipment.
• Many plants are beginning to internally generate electricity. This generation adds to the fault capacity of the system.
• Operating procedures may have changed. A bus tie circuit breaker that was normally open may now be normally closed. Such a change can greatly increase fault capacity.
• Technical standards can change. For example, in 1985 the protection requirements for liquid-filled transformers changed. Studies showed that many transformers were being mechanically damaged by high current through faults. The protection requirements became more stringent for such installations. Although the standards do not require existing systems to be changed, would it not make sense to at least review your system? The protection changes might be minimal.
• New installations or plant modernization may add capacity and other coordination streams to the system. For example, coordination studies require that the main breaker coordinate with the largest feeder device. If a larger feeder device is added later, the coordination study must be reviewed.
In general, short-circuit analyses and coordination studies should be reviewed at least every five years. These studies should be performed by a registered professional engineer.
Many consulting firms have the ability and the experience to perform them; however, since short-circuit analyses and coordination studies are specialized types of engineering services, not all architect and engineering firms have the experience to do them. Closely review the qualifications of the firm that you retain.
ANSI/IEEE standard Std-399, power Systems analysis, is the standard that covers most of the engineering studies that are key to the proper design and performance of an electrical power system. The Brown Book is part of the IEEE color book series and should be referenced when you are deciding what studies to perform and how to perform them.
Proper selection, sizing, and calibration of the protective devices in a power system directly affect safety, efficiency, and economics. Common sense and regulatory requirements dictate that a short-circuit analysis and coordination study should be performed.
Arc-Flash Study. The arc-flash study is performed to determine the incident energy to which workers will be exposed if an electrical arc occurs. This study is described in some detail in Section 4.
FIRST AID
This handbook provides general coverage of the subject with expanded information on handling electrical injuries. Potential first aid givers should remember four very important points. Before an accident happens:
• Obtain hands-on first aid training for yourself and all employees. Such training may be obtained from the American heart association, the American Red Cross, or local sources such as fire departments or police departments.
If an accident does happen:
• Act quickly!!! You may be the only person who can prevent a death.
• Do not administer first aid that you are not qualified to administer. Injuries can be aggravated by improperly administered first aid.
• Get qualified medical help quickly. Paramedics and emergency medical technicians are trained to provide emergency first aid and should be summoned as soon as possible.
This handbook is not intended to be used as a first aid training manual. Table 5 summarizes the first aid steps that are discussed in the following sections.
General First Aid
Act Quickly. Remember-you may be the only person between the victim and death.
Whatever you do, do it quickly. This does not imply that you should act impetuously. Your actions should be planned and methodical, but you should not waste any time. Do not attempt to perform procedures for which you have no training or experience. Improperly applied procedures can be deadly.
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TABLE 5 general First aid procedure
• Act quickly.
• Survey the situation.
• Develop a plan.
• assess the victim's condition.
• Summon help if needed.
• Move the victim only if danger is imminent.
• establish a de-energized accident scene.
• Administer required first aid:
Shock
Electrical burns
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Survey the Situation. Remember that your purpose as a first aid giver is to help resolve the problem, not contribute to it. If you are injured in the process of administering first aid, you cannot help the victim. If your preliminary assessment indicates that you need to wear safety clothing, put it on first, then administer aid. Table 6 lists key points that should be checked before you rush in.
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TABLE 6 First aid Checklist
• is the circuit still energized?
• is the victim contacting the circuit?
• are noxious gases or materials present that may cause injury?
• is fire present or possible?
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TABLE 7 What to Do If the victim is responsive
• ask the victim what is wrong.
• assess the victim's condition and treat the injuries as best as possible.
• treat the worst injuries first.
• When the victim is out of immediate danger, or if you are unable to help because the injuries are beyond your abilities, summon help.
• attend to the victim(s) and keep them safe until help arrives.
• When help arrives, give the first aid workers your assessment of the situation and stand by to help.
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TABLE 8 the ABCs of First aid
- Airway
- Breathing
- Circulation
- Doctor
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Develop a Plan. After the initial survey of the situation, develop the plan of attack. The specifics of any given situation will vary; however, the following guidelines should be used:
• If the victim is in immediate danger, he or she should be moved to a safe position. (See the next section on moving the victim and later sections on rescue techniques.)
• If the victim is nonresponsive, assess his or her condition and respond accordingly. (See the later section on assessing the victim's condition.)
• If the victim is responsive, make him or her as comfortable as possible and summon aid.
Do not abandon the victim until aid has arrived.
• Constantly monitor the condition of the victim. Electric shock can cause delayed failures and irregularities of heart rhythm.
Assess the Victim's Condition. The procedures to be used in administering first aid depend on the condition of the victim. If the victim is responsive, no action may be required. Table 7 lists the procedures to perform if the victim is awake and responsive.
If the victim is not responsive, you must per form a "hands-on" assessment of his or her condition. Table 8 lists the ABCs of first aid. This memory device can help the first aid giver to remember the proper procedure when examining a nonresponsive victim.
One of the biggest surprises to those who have not worked with accident victims is that the trauma of the accident can induce severe bleeding through the mouth and/or vomiting. Be prepared for these conditions before working with an injured person. When you have prepared yourself for this situation, begin the ABCs.
• A-Check the victim's Airway. FIG. 1 illustrates the correct way to clear an injured person's airway. Remember to avoid moving the victim and to keep the victim's spine straight to avoid aggravating an injury. Caution: an accident victim may suffer from involuntary muscular reflexes and other such spasms. The strongest muscle in the human body is the jaw. Because of this, rescue workers should put their fingers into the victim's mouth only when absolutely necessary.
FIG. 1 Clearing the airway of an injured worker.
Start by opening the victim's mouth as shown in FIG. 1. Search the mouth for foreign matter or other objects that may be blocking the air passage. Many times the victim's tongue may be blocking the air passage. To fix this problem, put your hand behind the victim's neck, gently pull the jaw forward, and, if required, carefully tilt the head back. If the air passage is clear and the victim is still not breathing, you should perform resuscitation.
• B-Check the victim's breathing. First check to see if the victim is breathing. This can be done by observing his or her chest to see if it is moving. Then place your ear close to the victim's mouth and nose and listen carefully. If the victim is breathing but choking or gurgling sounds are heard, clear the victim's airway.
• C-Check the victim's Circulation. Circulation should be checked by feeling for the victim's pulse at the carotid artery as shown in FIG. 2.
To find the carotid artery, place your fingertips gently on the victim's larynx. Gently slide the fingers down into the groove between the wind pipe and the muscle at the back of the neck. The carotid artery is located in this area. Gently feel for the pulse. Table 9 shows the steps to take for the various combinations of problems that may be found.
FIG. 2 Checking the circulation.
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TABLE 9 how to handle Unresponsive victims
Breathing-pulse normal Make victim comfortable. If help has not been summoned, do so and stand by until it arrives.
No breathing-pulse normal perform mouth-to-mouth resuscitation until breathing is re stored or until help arrives and takes over.
Breathing normal-no pulse perform heart-lung resuscitation (CPR) until pulse is re stored or until help arrives and takes over.
No breathing-no pulse perform heart-lung resuscitation (CPR) until pulse is restored or until help arrives and takes over.
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• D-Summon the Doctor. After the victim's condition has been stabilized, summon help.
If the resuscitation efforts are proving unsuccessful, the first aid giver may want to summon more qualified assistance even though the victim is not yet stabilized.
Summon Help If Needed. One of the most difficult decisions is to determine when to summon help. If help is not summoned soon enough, the victim may die. On the other hand, if the first aid giver leaves to summon help, the victim may die. No concrete rules can be given here; however, the following guidelines may help:
• relieve any immediate danger to the victim before summoning help.
• perform the ABCs before summoning help.
• If the victim is not breathing or has no pulse, perform resuscitation before summoning help.
• If anyone else is in the area, yell or call for help while performing the preliminary accident assessment.
Remember that the first aid giver is in charge of the victim until more qualified help arrives. Do not abandon the victim if immediate aid is required.
Move the Victim If Danger Is Imminent. Unless they are in imminent danger, accident victims should be moved only when necessary and only by personnel who are qualified to move them. A victim of violent injury, such as a fall, may have spinal or other internal injuries. Moving such a victim could cause increased problems including paralysis or even death. Moving an injury victim is discussed in detail in the "rescue Techniques" section in this section.
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TABLE 10 Typical Symptoms of electric Shock
• Victim may lose consciousness. This may occur at the moment of contact; however, it can also occur later.
• Victim has a weak or irregular pulse.
• Victim has trouble breathing or has stopped breathing.
• Small burns may appear at the entry and exit points of the electric current.
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TABLE 11 precautions for performing First aid on an electric Shock victim
• Do not touch any energized wires with any part of your body or with any conductive tools or equipment.
• Do not touch a victim who is still in contact with an energized wire with any part of your body or with conductive tools or equipment.
• Do not try to move any energized wires unless you are qualified to do so. Qualified in this instance means that you are trained in the performance of such a procedure and are able to avoid electrical hazards.
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TABLE 13 First aid procedures for Unconscious electric Shock victims with Symptoms
• Check the ABCs. If the victim is not breathing or has heart irregularities, perform resuscitation as described later in this handbook.
• If wounds are evident, cover them with sterile dressings.
• If external burns are evident, they should be cooled using clear, pure water.
• Try to cool burns with sterile compresses.
• Immediately seek medical aid.
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TABLE 12 First Aid Procedures for Conscious Electric Shock Victims Who Exhibit No Symptoms
• Keep the victim still and quiet. Remember that heart and respiratory problems can be delayed in electric shock victims.
• Monitor the victim's condition for at least one hour.
• If the victim continues to show no symptoms, take the victim to a doctor for a thorough examination.
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Establish a De-energized Accident Scene. Before physically approaching a victim, establish that the scene is de-energized. If the scene continues to be supplied electrical energy through an installation failure or downed power line, it is critical to involve utility, police, and emergency medical service personnel. Urgent confirmation is needed that both the electrical energy supply as well as the risk of capacitance are addressed to place the scene in an electrically safe condition for first responders, paramedics, and public safety professionals including fire and police.
First Aid for Electric Shock. Electric shock is one of the most difficult of all injuries to diagnose. In some cases, even if the injury is fatal, no external signs may be visible. Table 10 lists some of the clues and symptoms that may be present when a victim has received an electric shock.
Many prospective first aid givers are themselves injured when they contact an energized wire or a victim who is still in contact with an energized wire. Table 11 lists the precautions for working on or around accident victims who may be in contact with live wires. After cut ting the power to the circuits or removing the victim from contact, if the victim is responsive and shows no signs of breathing or heart problems, the procedures listed in Table 12 should be followed. After cutting the power to the circuits or removing the victim from contact, if the victim is nonresponsive, the procedures listed in Table 13 should be followed.
First Aid for Electrical Burns. Electrical burns may be visible at the skin surface or internal in the victim's body. External burns may be caused by the following:
• Heating from contact with an electrically energized surface
• Flash radiating from an electrical arc
• Fabric or installation ignition and burning due to an electrical arc
• Electrical blast Internal burns are caused by current flow causing resistive heating (Joule heating) to the body's tissues.
Internal burns are virtually impossible to diagnose in the field. The symptoms of internal electrical burns are identical to the symptoms caused by severe electric shock. In addition to the symptoms described in Table 10, the victim may also experience significant pain caused by the damaged tissue. External burns are similar to thermally induced burns caused by fire or other heat sources.
For both internal and external burns, the first aid techniques are similar to those given in Tables 12 and 13.
One extremely important additional procedure for external burn victims is to cool the burns as quickly as possible. A shower or other source of clean, cool water can be used.
Since the treatment of burns is a very specialized medical procedure, qualified medical help should be obtained as quickly as possible.
Resuscitation (Artificial Respiration)
Breathing trauma is one of the two very serious symptoms that result from severe electric shock or internal burns. When breathing is stopped or made irregular by electricity, it must be restored by resuscitation. Over the years many different types of resuscitation have been developed. Mouth-to-mouth resuscitation is the current preferred technique.
To be most effective, resuscitation must be started as soon as possible after breathing has ceased. FIG. 3 shows a curve that approximates the possibility of success plotted against elapsed time before the start of resuscitation. FIG. 4 illustrates a currently accepted procedure for the performance of artificial respiration. Caution: With the proliferation of communicable diseases such as acquired immunodeficiency syndrome (AIDS) and hepatitis, the decision of whether to perform lifesaving mouth-to-mouth resuscitation has become much more difficult.
Instruments such as breathing tubes should be used to protect the victim and the rescuer.
FIG. 3 Elapsed time versus possibility of success for artificial respiration. Curve showing possibility of success plotted against elapsed time before start of resuscitation.
FIG. 4 Steps a, b, c, and d illustrate the procedure to properly position your hands prior to performing CPR.
Heart-Lung Resuscitation
Heart-lung resuscitation is also called cardiopulmonary resuscitation (CPR). This technique should be applied when the victim has no pulse and no respiration. The procedure should be started as soon as possible to maximize the probability of successfully restoring full function to the victim.
Remember that while CPR is being performed, the first aid giver is actually pumping blood and breathing for the victim. Do not give up until qualified medical personnel say to.
CPR has two separate but equally important parts: rescue breathing and chest compressions. The rescue breathing is performed to force air into an unbreathing victim's lungs.
The chest compressions are used to compress the heart and force blood through the victim's circulatory system. Before CPR is performed, the ABCs described earlier in this section should be checked. See Table 8 and associated text.
Chest Compressions. If the victim has no pulse, chest compressions should accompany the rescue breathing. The following steps should be used:
1. properly position your hands on the victim's chest (see Figs. 4, 5, and 6)
a. Kneel facing the victim's chest. Find the correct hand position by sliding your fingers up the rib cage to the breastbone as shown in FIG. 4.
b. place your middle finger in the notch and the index finger next to it on the lower end of the breastbone.
c. place your other hand beside the two fingers.
d. place the hand used to locate the notch on top of the other hand. Lace your fingers together. Be sure to keep your fingers off of the victim's chest. Position your shoulders over your hands with your elbows locked and your arms straight. (See FIG. 5 for alternates to this hand position.)
2. At the rate of 100 compressions per minute, compress the breastbone 1½ to 2 inches, as shown in FIG. 6.
3. Repeat step 2 thirty times.
4. Stop and give the victim two rescue breaths as described under rescue breathing above.
(Note that steps 2, 3, and 4 should take approximately 15 seconds.)
5. Recheck the victim's carotid artery pulse for 5 seconds.
6. If no pulse is found, repeat steps 1 through 5.
7. Continue this process until one of the following occurs
a. another trained person takes over CPR from you.
b. EMS personnel arrive and take over care of the victim.
c. You are too exhausted and unable to continue.
d. The scene becomes unsafe.
Rescue Breathing (Mouth-to-Mouth Resuscitation). If the preliminary assessment indicates that the victim is not breathing, mouth-to-mouth resuscitation should be performed as follows:
1. Open the airway, clear the mouth, and tilt the head back, as shown in FIG. 1.
2. gently pinch the victim's nose to seal it closed, as shown in FIG. 7.
3. Take a deep breath and seal your lips around the victim's mouth, creating an airtight seal.
4. Gently blow into the victim's mouth for 1½ to 2 seconds. While blowing, watch to be sure the victim's chest is rising.
5. Stop blowing and allow the victim's lungs to exhale.
6. Repeat steps 4 and 5.
7. Stop the procedure and watch the victim for 5 to 10 seconds to determine if the victim is breathing on his/her own.
8. If the victim is not breathing normally, repeat steps 4 and 5 until the victim starts breathing normally or until qualified help arrives to relieve you.
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