a.IV accessallows the administration of crystalloids, blood products, and med- ications. Venous catheterization of trauma patients by paramedics is done routinely, even though outcome data supporting this practice are lacking. Cur- rently, pragmatism suggests that IV access should be attempted but without delaying transport or other interventions (especially airway management and hemorrhage control). To limit the on-scene interval, attempts at IV placement should be made during extrication, while awaiting transport resources, or during transport to the hospital. Large-bore (16 gauge) peripheral IV lines are preferred for major trauma patients. If IV access is not readily available consider IO access.
b.Failures.A small number of trauma patients will arrive at the hospital with- out IV/IO access because of short transport times, uncooperative patients, or
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Chapter 9 rPrehospital and Air Medical Care 93 other more pressing priorities (e.g., airway management, spine protection, or hemorrhage control).
c.Fluid therapy in the field. Significant controversy exists regarding the composition, amount, and ultimate clinical goals of fluid therapy in trauma patients. No specific heart rate or blood pressure targets exist to guide the amount of fluid; rather, controlled or limited fluid resuscitation (sometimes referred to as “permissive hypotension”) appears beneficial, although the end- point and fluid makeup are still uncertain. Recent data suggest that resusci- tation to a palpable pressure or SBP>70 mm Hg is sufficient for penetrating trauma, while recommendations for blunt trauma range from an SBP of 90 to 110 mm Hg.
2.Rapid chest decompression/needle thoracostomy
a.Indications.Needle thoracostomy should be performed when a tension pneu- mothorax exists or is suspected.Any trauma patient with severe respi- ratory distress should be evaluated immediately for tension pneu- mothorax.In the field, the diagnosis is critical and must be treated before arrival at the hospital. Tension pneumothorax should be suspected in the trauma patient who is short of breath or hypotensive and withanyof the following features:
i. Decreased breath sounds
ii. Tracheal deviation (away from the involved side)
iii. Distended neck veins (this may not be seen in the patient who is hypov- olemic)
iv. Hyperresonance to percussion of the chest (on the involved side)—difficult to assess in the field environment
v. If the patient is intubated, increasing difficulty in bag-valve ventilation can be the earliest or sole indication of a developing tension pneumothorax vi. Respiratory distress
b.Procedure.Treatment should proceed rapidly once the diagnosis is suspected;
if incorrect, the only harm is creating the need for a formal tube thoracostomy in the receiving facility, whereas failing to recognize and treat can lead to death.
Decompress the affected side of the chest by inserting a large-bore IV catheter (12 or 14 gauge) perpendicular to the skin at the second or third intercostal space in the midclavicular line, or the third or fourth interspace in the anterior axillary line (Fig. 9-5). Advance the catheter until a rush of air occurs from the open distal end, or until the hub reaches the skin. Common errors include placing the needle either too close to the sternum or cephalad to the second intercostal space (making heart or great vessel puncture possible), or placing the needle under instead of over a rib (making puncture of the neurovascular bundle, which runs in a groove under each rib, possible). After placement, withdraw the needle, but leave the catheter in place to prevent reaccumulation of pleural gas. If the patient’s condition worsens, suspect occlusion of the first catheter and place a second needle.
i.Bilateral decompression.Occasionally, especially in the patient on pos- itive pressure ventilation or with severe obstructive lung disease, bilateral tension pneumothorax can develop. The asymmetry described above with respect to tracheal and chest findings may not be present. If uncertain, both hemithoraces should be decompressed.
ii. Therapy after needle thoracostomy.At the receiving facility, a chest tube is usually placed for definitive treatment once needle decompression is performed (whether or not clinical success occurred with the latter). Once the chest tube is in place, the catheter(s) can be withdrawn.
3.Tourniquets.If pressure fails to control hemorrhage from an extremity injury, a tourniquet should be applied. Controversy over tourniquet use began with reports of amputation or fasciotomies when the devices were left in place too long. Tourni- quets used during this period were improvised with rubber tubing, rifle slings, and belts, and were often inappropriately narrow resulting in further tissue injury at the necessary tension to stop arterial bleeding.
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Figure 9-5.Technique for needle thoracostomy. (Modified from Champion HR, Robbs JV, Trunkey DD. Trauma surgery. In: Rob and Smith’s Operative Surgery. London: Butterworth, 1989:57, with per- mission.)
Several recent case series and case reports have shown that tourniquet use on the battlefield has resulted in neither limb loss nor permanent disability, even among those who had tourniquets applied that in retrospect were not required.
Civilian prehospital studies evaluating the safety and effectiveness of tourniquets are lacking. If direct pressure fails, a tourniquet should be applied. Tourniquets may also be needed in MCIs related to explosive blasts, terrorism, or criminal violence. In these cases there will often be more casualties than skilled providers, and evacuation from the scene may be delayed due to tactical concerns during a criminal or terrorist attack, or because of collapsed and unstable structures in the event of an explosion.
4.Splinting
a.Indications.The purposes of splinting are to prevent further injury, decrease blood loss, and limit the amount of pain the patient will have with movement of that extremity during extrication and transport. An injured extremity should be splinted in anatomic position if possible, with the splint extending to the joints above and below the fracture site for stabilization. If the patient refuses, or if resistance to straightening exists, splint in a position of comfort. Dressings should be applied to any open wounds before splinting.
b.Splint types.A large variety of splint designs will appear on patients brought to the emergency department. They can be as simple as a rolled-up newspaper, or as complex as a vacuum or traction splint.
i.Cardboard splints, with or without foam padding, are intended for single use.
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Chapter 9 rPrehospital and Air Medical Care 95 ii. Board splints are common and durable, made of straight pieces of wood,
metal, or plastic cut to various lengths.
iii. Air splints, which encircle the injured extremity, are inflated with air to impart stiffness. They are usually clear to allow visualization of the underlying structures. Over inflation can cause neurovascular compro- mise.
iv. Vacuum splints incompletely encircle the injured limb. Instead of air being blown into them, air is withdrawn and a vacuum is produced, which stiffens the splint.
v.Traction splints are used for femur fractures. Thomas half-ring splints and Hare traction splints are those most commonly used. Specific training is required for proper placement.
vi.Ladder splints are made from heavy gauge wire in a ladder shape. They are useful for splinting extremities that cannot be straightened because they are bendable and can be shaped to match the extremity. The SAM Splint, with a flexible aluminum alloy core covered with closed-cell foam, is similarly flexible.
vii. Pelvic binders and compression devices may be made out of bed sheets or commercial devices with compound pulley systems and Velcro to close a disrupted pelvis.
c.Complications.Although splinting is safe and effective in most patients, complications can develop, including:
i.Neurovascular compromise. Whichever splint is used, distal neurovascular status must be checked before and after application of the splint. Also, if any patient movement has occurred, the patient reports more pain, or the extremity is noted to be cyanotic or edematous distal to the splint, reexamine the extremity and splint. It is also advisable to periodically check the neurovascular status, even if none of the above occurs. When impaired neurovascular status is seen distal to an injury, the splint should be loosened or adjusted, and the neurovascular status rechecked.
ii. Pain. When the patient reports pain, search for neurovascular compromise or malpositioning. Gentle repositioning should resolve this condition.
5.Axial spine immobilization
a.Prehospital indications.Despite the lack of supporting literature, the entire axial spine is immobilized by prehospital personnel whenever the mechanism of injury, injury pattern, or physical examination indicates the possibility of any spinal injury. Patients with obvious physical findings (e.g., bony crepi- tation, palpable step-offs) or those with neurologic findings (e.g., paresthesia, weakness, paralysis) consistent with spine or cord injury should always receive cervical immobilization before transport.
b.Clinical assessment of the spineoften cannot be performed by field per- sonnel because of time, space, distracting injury, altered consciousness, and other concerns (e.g., airway, bleeding control, vascular access) that can pre- clude adequate in-field evaluation to rule out spinal injury. The rule in prehos- pital care is to maintain a high index of suspicion for such injuries with liberal application of spinal immobilization.
c.The need for spinal immobilizationoccurs at the injury scene and contin- ues through extrication, transportation, and stabilization in the ED. Immobi- lization is accomplished with the least possible neck movement, and ends only when physical and/or radiographic findings definitively rule out injury.
d.Types of immobilization devices.No single method or combinations of methods of immobilization consistently place the spine in neutral position or prevent all motion in the axial spine.
i. Cervical collars(c-collars). These rigid one- or two-piece devices encircle the cervical spine and soft tissues of the neck, providing (when properly fitted) a snug fit between the tip, the chin, and the suprasternal notch of the anterior chest, and between the occiput and the suprascapular region of the back. These collars limit movement of the head in the coronal and
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transverse planes, minimizing lateral and rotary motion. They do not, however, provide adequate immobilization in the sagittal plane (flexion–
extension motion). For this reason,a rigid cervical collar alone is inadequate for effective spinal immobilizationand is always used in conjunction with a cervical immobilization device (CID) and a spine board (short or long). Soft neck collars (foam supports covered with loose-weave material) are ineffective at limiting motion of the head and are not intended for use in spinal immobilization.
ii. CIDsare made of plastic, cardboard, or foam. They act to limit both lateral and rotary motion, and they possess restraining straps that are positioned over the patient’s forehead and chin. The CID affixes the patient’s head and c-collar to a rigid spine board, limiting the head movements of flexion and extension. A CID can be fashioned from blanket rolls, blocks, or sandbags placed alongside the head, with fixation to the spine board via a wide (2 to 3 in) adhesive tape placed over the forehead and chin.
iii. Spine boardshave not been demonstrated to benefit patients with spinal injury and have been associated with respiratory compromise, patient agi- tation, and pressure ulcers. Use of spine boards should be limited to the transfer of the patient to the EMS stretcher and the time on the board should be minimized. Spine boards are termed “short” or “long,” depend- ing on the most distal portion of the patient immobilized. Short boards limit flexion and extension from the head to the hips, minimizing movement in all portions of the spine (cervical, thoracic, lumbar). Short boards are pri- marily used if patient access is limited (e.g., entrapment in a vehicle, or confined space extrication) and stability in the axial spine is needed before and during the extrication process. Once extrication is performed and com- plete access to the patient is achieved, the patient should be log rolled onto the EMS stretcher and kept supine. Straps provide fixation points at the thorax, hips, and lower extremities (above the knees). Padding between the lower extremities and under the knees enhances both stabilization and patient comfort.
a)Secondary pain after immobilization.With any of these devices, immobilization itself can produce symptoms of discomfort (e.g., occip- ital headache; neck, back, head, mandible pain). Padding behind the occiput and in the areas of lordosis and kyphosis make intuitive sense, and may be especially important in the pediatric and elderly popula- tion, given their anatomy. Once patients arrive at the hospital, prompt removal after appropriate assessment will limit pain and skin break- down.
IV. AIR MEDICAL TRANSPORT
On the basis of the experience of the Korean and Vietnam Wars, air medical transport has grown to become an integral part of trauma care in the United States. Over 800 private, hospital-based, public service, and military air medical helicopters transport more than 300,000 patients annually. Two-thirds of the transports are interhospital, with the remaining one-third transported directly from the scene.