By Steve Shotz
Mountain biking collisions often involve high speeds, impact with hard and/or sharp objects, or falls from a significant height. Impacts involving these significant MECHANISMS OF INJURY can result in serious damage to the chest, which may not be immediately apparent because the damage is internal. The greater the force involved, the more serious the injury and the greater the need to do a thorough assessment for other associated injuries. This paper covers some common injuries to the chest. Part II will cover the different types of pneumo- and hemothoraces.
BLUNT injuries are caused by impact with an object that is typically not sharp and does not penetrate the skin, e.g. a rounded rock or a tree trunk. PENETRATING injuries are usually caused by impact with a sharp or narrow object, e.g. the end of a piece of rebar or tree limb or other pointed object. Penetrating injuries break the skin and enter the chest cavity.
I. General Assessment
Part of your complete RAPID BODY SURVEY should include PALPATING (gently touching) and observing the chest for deformities, CONTUSIONS (bruises), abrasions, punctures, bleeding, tenderness, lacerations, swelling and CREPITUS (a grinding sensation or noise caused when pieces of bone rub against each other). If you find any of these signs, completely expose the patient's chest down to the skin, so you can see the injury directly. As always, use BODY SUBSTANCE ISOLATION when examining the patient. Watch for equal rise of the chest on both sides, shallow breathing, painful breathing, or unusual effort needed to breathe. A normal adult breathes from 12-20 times/minute. Breath rates of less than eight or more than 24, along with other signs of poor ventilation, signal a significant breathing problem. HEMOPTYSIS (coughing or spitting up blood) is a bad sign, as are signs of shock. Remember to assess for multiple injuries, including head, neck, and spine.
II. General Treatment
Internal chest injuries require emergency evacuation to a hospital for definitive assessment and treatment. Typical protocols apply, including close monitoring of the airway, breathing and circulation (ABCs). When breathing is impaired, provide supplemental oxygen and consider the use of airway adjuncts if you are properly trained and the patient cannot maintain an open airway. Monitor and treat for shock. Transport the patient using a backboard and cervical collar. Take vital signs every five minutes.
III. Types of Injuries
- Rib Fractures: These are the most common blunt chest injury. Injuries to the first and second ribs (the top-most ones) result from significant force and signal the need to check carefully for other injuries to the head, neck, internal organs and abdomen. Rib fractures are indicated by local tenderness and crepitus over the fracture and pain when inhaling. The patient will often hold his ribs and breathe in short, shallow breaths. Simple rib fractures, without other injury, require minimizing movement and monitoring of airway and breathing.
- Flail Chest: This is a fracture of three or more ribs in two or more places, or a fractured sternum in addition to several fractured ribs. It creates a section of ribcage that floats relatively free from the rest of the ribcage. It is characterized by its PARADOXICAL MOTION (the movement of the flail segment in when the rest of the chest moves out and vice-versa). Other signs include DYSPNEA (trouble breathing), TACHYPNEA (rapid breathing), and TACHYCARDIA (rapid heart rate). Flail chest is very painful and impairs adequate breathing. Flail chest often involves PULMONARY CONTUSION. Flail chest video.
Stabilize the flail segment by binding a bulking dressing, jacket, or soft pack against the flail segment, using tape or large cravats, but not so tightly as to impair breathing. Use a backboard if available. The patient may be more comfortable lying on the injured side, with enough padding.
- Traumatic Asphyxia: Sudden crushing injuries to the chest - high speed collisions with trees or being pinned under a large rock - increase the pressure in the chest cavity and prevent blood from moving properly through the heart, essentially causing a backup of blood. Look for CYANOSIS (blue-purple skin color) of the neck and face, bleeding in the whites of the eyes, bruising around the eyes, and distended jugular veins. The face may be swollen and there may be blood in the nose or ears. While secured to a backboard, elevate the patient's head 30 degrees to reduce pressure to the head. As with all breathing emergencies, maintain airway, give supplemental oxygen, and ventilate if necessary.
- Pulmonary Contusion: Lung tissue is bruised and the AVEOLI fill with blood, interfering with air exchange. This typically develops over hours and is common with flail chest. Monitor patient's ABCs.
- Pericardial Tamponade: This is a type of cardiac injury in which blood or other fluid collects in the tough sac that surrounds the heart, preventing the heart chambers from filling with blood. As the pressure in the sac increases, the heart is compressed until it cannot pump and arrests. During the development of pericardial tamponade, the patient's pulse will become weak, blood pressure will be low, and the difference between the systolic and diastolic pressures will become smaller. Also characteristic is JUGULAR VEINOUS DISTENTION, the swelling of an external jugular vein. If you listen to the patient's heart, you may note muffled heart sounds. There is no additional first aid-level field treatment for this injury beside management of ABC's and rapid transport.
- Commotio Cordis: This is a cardiac arrest due to ventricular fibrillation in a healthy person, typically a young male athlete, that results from a sharp blow to the chest. The impact must occur at precisely the right moment before the T-wave peak of the heart rhythm. Resuscitation in the backcountry is rare. Treat with CPR and use of an automated external defibrillator.
Remember to always perform a thorough initial assessment of your patient and keep in mind that in any accident involving a significant mechanism of injury, there is likely to be more than one problem. Don't get fixated. Always monitor the patient's ABC's closely and frequently and intervene according to your level of training. Take precautions for spinal injury and prepare to backboard the patient if necessary. Watch for shock and changes in vital signs. Take your SAMPLE history so you can report it to the paramedics. Evacuate any patient with suspected internal chest injuries immediately to definitive care at a hospital.
Part II of this article will conclude with the remaining common complications of chest injury.
Steve Shotz (sjshotz [at] sbcglobal [dot] net) is an Emergency Medical Technician and an Outdoor Emergency Care instructor for the National Ski Patrol. He welcomes your questions on first aid practices.