Body Trauma
Page 2
Resuscitation equipment is available in all transport vehicles. The most important principle in patient transport is to deliver the victim quickly and safely to the nearest appropriate hospital. A contingency plan for foul weather is needed.
Dead victims don't enter the Emergency Medical System (EMS) but must be taken to the proper facility as directed by the coroner or medical examiner.
Transfer of patients: This refers to the transfer of a patient from one trauma center to another of a more sophisticated level (see "Levels of Trauma Care" on page 14). Criteria for considering early transport of the injured victim are summarized in Figure 1 (page 10). An example of a transfer sheet is included in Figure 2 (page 12).
The trauma victim's illness severity is calculated from vital signs, specific lab tests and other variables. Each patient is assigned what is called the revised trauma score. It gives an estimate of survival potential and consists of:
• Respiratory status
• Cardiac status (blood pressure, pulse, etc.)
• Glasgow Coma Score (see chapter five)
Not only does this derived number permit the trauma surgeon to predict outcome, it also gives an estimate of the patient's potential for developing major complications.
The severity of the injury is assessed in the field by a paramedic before the trauma surgeon becomes involved. Field assessment of the degree of injury is determined by the following four factors:
1. Abnormal body functions such as low blood pressure and fast pulse that describe shock or abnormal respirations and neurologic findings that suggest a severe head injury
2. Obvious disruption of the victim's anatomy, e.g., traumatic amputation, impalement, gaping chest or belly wound
3. The mechanism of injury—blunt or penetrating, the caliber of the gun, speed of the motorcycle, length of the knife, distance of the fall, etc.
4. Associated illnesses, such as diabetes, hypertension, heart failure, chronic lung disease or kidney failure
Once the paramedic identifies major life-threatening injuries he institutes emergency care before moving the victim. The pattern of identifying and treating trauma emergencies is ritualized to avoid mistakes.
Prehospital protocols refer to specific instructions given to paramedics and EMTs as part of their training to assure reproducible and
safe care for all trauma victims. These kinds of treatment plans are also available for a variety of medical conditions seen "in the field." The goals of all emergency care protocols are:
• To provide lifesaving care in the field
• To provide comfort to victim
• To transport victim to the appropriate hospital in a timely fashion
The elements of prehospital "cookbook" emergency care plans are taught in a defined order to be followed by every emergency responder in exactly the same way. The concept is to eliminate freelancing and creative thinking in the management of life-threatening emergencies. Anyone who has been responsible for another human who was in the act of dying knows the intense fear that surrounds providing acute care. It's easy to forget what to do for the victim.
Thus, the basic resuscitation scheme used by all EMTs, paramedics, nurses and physicians is ABCDE. This translates into looking for and solving the following acute problems, which, if not reversed, may result in a life-ending tragedy.
• A is for airway. Assure nothing is blocking free flow of air in the mouth and trachea.
• B is for breathing. Make certain air exchange is actually occurring.
• C is for circulation. The heart is beating, pulses are present and any bleeding is stopped.
• D is for disability. Check the nervous system. Is the victim verbally responding? Are eyes open? Arms moving? Legs?
• E is for exposure. Take off the victim's clothes, if necessary, and check for other hidden life-threatening injuries.
Triage refers to the sorting out of trauma victims according to the severity of their injuries. This process occurs in the field, in the trauma room and in the setting of mass casualties. It's crucial to know that half of all trauma victims who will eventually die never reach a hospital. Two-thirds of those who die in spite of acute medical care will expire within the first four hours.
Your "first responder" character should know whom to let die at the scene—unless you are purposely creating conflict by having him make the wrong decision or involving him in a dispute with someone else at the scene about triage priorities.
Why do trauma victims die after reaching the hospital? The reasons include:
• Delayed transportation to a trauma care facility
• Improper triage in the field with missed vital injuries
• Inadequate or delayed resuscitation
The paramedic must consider four situations when performing triage in the field:
1. Whom to ignore because they are going to make it without attention (minor lacerations, abrasions, etc.)
2. Whom to let die at the scene because no amount of care will reverse their overwhelming injuries (massive head injuries, profound shock from blood loss, etc.)
3. Who has life-threatening injuries that must be reversed immediately at the accident scene (obstructed airway; major ongoing bleeding requiring pressure dressings; head or neck injuries requiring stabilization, urgent evacuation and hospital treatment; etc.)
4. Who needs care for major injuries that are not life-threatening (broken bones, bleeding, uncertain internal injuries, etc.)
Sadly, the sickest victim isn't always the one you pay most attention to when sorting injuries. It's a numbers game and it's tough.
Levels off Trauma Care
Now we'll discuss in detail the different levels of trauma care available throughout the U.S. and the way various hospitals mesh together to form a regional trauma care system. There are four recognized levels of trauma care expertise—all of which are vital for a smoothly run national system of trauma care delivery.
Level I trauma centers are major urban medical centers with all surgical specialties available, including a neurosurgeon, plastic surgeon, urologist, cardiac surgeon, orthopedic surgeon, ophthalmologist, ENT surgeon, pediatric surgeon and hand surgeon. A trauma surgeon is on call in-house (surgical resident) at all times. Intensivists work in multi-specialty critical care units (ICU). There exist an excellent blood bank, laboratory facility and support systems, such as rehabilitation, social services and religious support.
Level II trauma centers are urban community hospitals with most surgical specialties represented. They handle 95 percent of all trauma. Level II centers have board-certified general surgeons with trauma experience and many but not all support services. More complex cases are referred to level I centers.
Level III trauma centers are usually rural hospitals. Surgeons aren't on call twenty-four hours a day specifically for trauma, but they are readily available. Most other surgical specialties are available as well. Less complicated cases, for example, patients with single system trauma, may be handled at these facilities.
Level IV trauma centers are rural hospitals or clinics with minimal resources, but they are the only care available for some trauma patients. There may not be a doctor present, so paramedical personnel play a vital role in resuscitating and transporting trauma victims.
The transport of the victim to a big-city level I superspecialty medical center characterizes a continuum of expertise and opportunity. Every link in the national trauma system is vital for the effective running of the program. But some victims only suffer from one injury.
Single system trauma involves only one organ system in the impact event. For example, head trauma by itself causes a majority of traumatic deaths and many long-term disabilities. A fractured leg is also single system trauma but carries little potential for prolonged disability and rehabilitation.
Multiple system trauma is seen in auto accidents, falls and other extreme accidental impacts where deceleration affects any organ that is poorly anchored and not well prot
ected. That is, the aortic arch, spleen, kidney or intestine may continue to move after the body halts abruptly with collision or contact with the ground. In addition to multiple fractures, internal organs are often torn or ruptured, creating a variety of clinical problems for the surgeon. And because so many impacts occur as different force vectors are applied, it isn't surprising that, at times, injuries go undetected.
Missed injuries just happen. Think about the trauma center setting and the chaotic way victims of serious trauma come into the hospital. It's difficult to know exactly how the accident occurred. At first, there's little information about the event. A number of factors contribute to the failure to diagnose certain conditions:
• Fatigue—late at night, the surgeon has already put in a full day and another awaits and there are no residents to help.
• Poor history—occasionally what happened at the accident scene isn't transmitted to the treating doctors. Also, the history is often given by a belligerent patient who may be further confused by substance abuse, shock, concussion, etc.
• Severe, life-threatening injuries—these injuries may preoccupy the surgeon's initial interaction with the victim.
• Ventilator intubation—patient can't indicate the site of pain.
• Paralysis—patient can't localize pain.
• Examining doctor's inexperience—a physical finding may be missed or misinterpreted, or an x-ray may be misread.
• Breakdown in usual evaluation routine—doctor becomes distracted and omits parts of the physical exam or does not perform an essential x-ray.
While surgeons in the past have been reluctant to acknowledge that injuries were periodically missed, most trauma surgeons in the last few years have elected to "look the issue straight in the eye" rather than attribute omitted diagnoses to the inexperience of new surgeons. All surgeons miss something at some point in their careers.
In one study of trauma victims who underwent autopsy, the incidence of missed diagnosis was 34 percent! It is felt that available data suggests only about 5 percent of missed diagnoses caused death while an additional 23 percent of concealed injuries contributed to death. Half of all missed x-ray diagnoses in a Cook County (Chicago) study involved trauma patients. A lot of these patients were victims of inner city war.
Perhaps that sad fact is fitting as, historically, advancements in trauma care have been concentrated in times of conflict. War has educated doctors through the centuries and continues in the modern era to dictate how trauma surgeons care for civilian patients. A brief overview of developments that accompanied modern wars:
• American Civil War—use of antiseptics, amputation and horse ambulances in the field
• World War I—improved wound care, delayed closure of infected wounds to avoid abscess formation; blood loss related to shock, with sea water used to replace lost volume; field ambulances with motors
• World War II—blood transfusions used, rapid evacuation (about two hours), surgical units placed closer to the front lines, colostomy used for traumatic colon injuries
• Korean War—vascular surgery developed for repair of arteries, use of helicopters (evacuation time less than an hour), MASH units developed, kidney failure understood and dialysis developed
• Vietnam War—rapid helicopter evacuation (twenty to thirty minutes from field to hospital); massive IV fluid replacement for shock; realization that respiratory failure is secondary to shock and understanding of resuscitation, leading to new treatment strategies for what became modern critical care medicine
War wounds became better understood through these epic struggles as scientists began to study injury models as well as the effect of various ballistics on tissue. The U.S. Army had special teams in the field evaluating traumatic wounds during the Vietnam era and had research programs involving the study of projectile injuries in animal subjects. Surgical care improved as tissue insults became better understood.
Destructive Impacts
Different types of forces act on human flesh to cause damage and may act simultaneously or concurrently in the same victim. There are four forces that produce destructive impacts in a specific manner.
Impact-Producing Forces
High-velocity versus low-velocity projectiles: Rather than mass, it is the speed (and "tumbling") of a projectile that determines the extent of the damage.
Crush injuries: Soft tissue is squeezed between deep bony structures and whatever is pressing against the skin. The Oklahoma City federal building collapse witnessed many crush injuries. First, damage caused by the direct injury to crushed tissues occurs, followed by the release of toxic inflammatory substances from the area of the crush. "Washed out" into the blood stream when the victim is resuscitated, these toxins may cause lung and kidney failure.
Shear forces: One type of tissue shears against the tissue next to it, often because the first tissue decelerates or stops suddenly and another adjacent tissue keeps in motion. If solid, the organ rips and bleeds, and if hollow, for example, the bowel, the organ tears and perforates, releasing irritating body fluid.
Cavitation: This may be instantaneous and temporary, or permanent. A temporary cavity forms when tissue is compressed by an external force, creating a hole or tear in the tissue that then recloses when the force stops. As will be discussed in a moment, the best example is a gunshot wound that leaves a bullet track.
Automobile Accidents
Now, we'll examine the forces that may cause injuries to a person inside an automobile during impact. Serious injury occurs when a part of the body is struck by an object or another body. The fascinating part is the variable end results. Why variable? Because the differences in the force applied and the individual's anatomy are just enough to create an unpredictable and, at times, bizarre array of injuries.
Automobile accidents are so common that the mechanisms of injury deserve special mention. In addition to any torque or spinning motions created by the collision of one car with another or with a roadside object, there are three types of impact: frontal, rear and side.
A frontal or rear impact stops the car, but the occupants continue to move forward. The driver strikes the steering wheel; the passenger strikes the dash or windshield. Rear impacts snap the neck. Both traumatic events are more severe if the occupants aren't wearing seat belts or if the car doesn't have air bags or neck protection. These devices are designed to blunt the effects of moving inertia, to "cushion" the kinetic energy of the people in the car. Injuries may include:
• Flexion-extension injury to the neck
• Blunt chest trauma
• Compression of intra-abdominal organs with possible rupture
• Blunt facial trauma with fractured facial bones and lacerations, and
scalp lacerations
• Skull fracture, brain contusion, laceration, intracranial hemorrhage
Lateral, or side, impact may cause any of the above injuries as well as spinal fractures caused by rotation and compression of the torso or pelvis upon direct contact. Arm and leg fractures may also occur from lateral force. If the car rolls over, anything can happen.
Injury may be related to the restraining device, particularly the seat belt. Let it be said loud and clear that restraints prevent a vastly larger number of injuries than they cause. Three-point seat belts must be used with air bags as the latter are useless in lateral and rear impacts. Besides, when the air bag deflates, which is immediately after impact, any secondary hits will only be reduced by the seat belt.
Lap seat belts used alone may result in trapped bowel and intestinal rupture as well as flexion spinal cord injury. The use of diagonal belts only may cause neck and chest trauma. Thus, both are needed to protect the automobile occupant from serious harm during impact.
For a moment, consider the basic principles of physics that determine what happens during impact. Newton's first law of motion states that an object will remain in motion in a straight line until acted upon by some external agent or force. The passenger of a car
experiences impact when the car stops because his body is in motion as well. Not until the seat belt, air bag or dashboard intervenes does the driver's forward momentum cease. Which restraint or auto part is impacted partially determines the type and degree of injury.
The idea of acceleration is that of changing velocity. A body may be induced to move faster or slower or change direction. It accelerates or decelerates. To do so the body must acquire kinetic energy or energy on the run, moving energy, and when that body stops suddenly, all of that kinetic energy must be transferred to something else. If that something else is your character's body, he gets seriously hurt.
Other Destructive Impacts
Falls can be disastrous because of the acceleration of gravity, the increase in velocity of a falling body because it is pulled by Earth's gravitational forces. Each second during a free fall, the velocity of the falling body increases by thirty-two feet per second. What your character strikes also partially defines the traumatic injury. The results of a fall are determined by:
• The distance of the fall—a fall from a standing position to a tumble into the Grand Canyon.
• The body part first struck when contact with the ground is made— neck, head, arm, etc.
• The nature of the impact point—water, gravel, concrete, grass, shrubs, etc.
Any of the minor or major injuries described in part two may be the consequence of a fall, and there can be surprises in the degree of trauma resulting from different tumbles. A slip on the ice may result in a ruptured spleen, as I discovered recently in a young patient. And a fall from a cliff may cause only scratches and bruises.
Gunshot wounds are just as unpredictable. In a companion book in this series entitled Armed and Dangerous: A Writer's Guide to Weapons, Michael Newton covers basic ballistics. The following discussion focuses more on what happens to human flesh because of the peculiarities of ballistics and body structure.
As you can see in Figure 3 (page 20), bullets don't leave simple wounds. It is the velocity of the bullet that primarily determines the nature and extent of the wound, although this isn't the only factor, as a .45 caliber slug traveling at 850 feet per second will cause more damage than a .22 caliber bullet at 1000 feet per second. Part of the damage is due to the soft lead projectile, which disintegrates and disperses all of its kinetic energy in the flesh. A faster copper jacket bullet may pass through a body structure without causing much harm because a lot of its energy is still in motion after the exit wound. Add a few bone fragments to a disintegrating bullet and now you've got secondary missiles, which cause more damage.