Over the past 20 years there has been increasing emphasis on the development of trauma systems that cover geographical areas, such as a nominated state or region. The introduction of trauma systems has resulted in a 15–30% reduction in the risk of death, primarily in the area of preventable deaths.¹⁰ Although this reduction appears widespread, it has not been replicated in remote areas,¹¹ and is limited by the lack of examination of deaths that occur before a patient reaches hospital or after discharge. Additionally, the lack of examination of functional outcomes limits interpretation of the trauma system, as it is not clear whether the patients who survive have altered functional capacity. Despite these limitations, there is widespread agreement on the benefits of trauma system implementation, although the contribution of nursing care in such trauma systems is rarely considered or measured. Furthermore, the precise components of a trauma system that prove beneficial have not been identified.¹²

Prehospital Care

The debate regarding the relative benefits of stabilising a patient at the scene versus proceeding to the hospital as quickly as possible, is not new.¹³ Benefits are somewhat dependent on the proximity of effective trauma facilities, the level of knowledge and skills of the prehospital personnel available and the specific injuries and condition of the patient. The principle of the ‘golden hour’ remains in place today and suggests that, in order to improve outcomes, definitive care should be provided to patients as soon as possible, and preferably within 1 hour of the injury being sustained.^13,¹⁴ In countries with large distances and sparse populations this aim presents particular challenges and cannot be met in many regions. Despite these distances and transport challenges, recognition of life-threatening conditions, application of appropriate emergency interventions and prompt transport to the nearest appropriate hospital remain the principles of prehospital care.¹³^–¹⁵

In a number of regions, processes are in place to facilitate prehospital admission: personnel can notify the receiving hospital in advance, for those patients who meet predefined criteria. Identified patients generally have severe physiological compromise, or injuries from high-velocity causes that result in significant injury and associated poor outcomes. Early notification allows the assembly of a multidisciplinary group of health professionals who can provide immediate, expert assessment, resuscitation and treatment of critically injured patients.^16,¹⁷ Such trauma teams have been shown to provide benefit in the early management of multiply-injured trauma patients, and are reviewed later in this chapter.^10,¹⁶

Transport of the Critically Ill Trauma Patient

Transport of critically injured patients occurs at two stages in the patient’s care. Primary transport occurs from the place of injury to the first healthcare facility to provide care to the patient; this is sometimes referred to as prehospital transport. Secondary transport occurs between healthcare facilities; this is sometimes referred to as interhospital transport. This chapter concentrates on secondary transport, although many of the principles are similar for both stages of transport. Intrahospital transport principles are also relevant for critically injured patients being transferred within departments in a healthcare facility (see Chapter 6). Transport of a patient between healthcare facilities may occur for clinical reasons, such as specialist or higher levels of care being required, or for non-clinical reasons, such as bed availability. It is preferable for patient transfer to be for clinical reasons only; however non-clinical transfer is sometimes unavoidable.

Secondary transport of critically injured patients may occur via either ground or air (by fixed-wing or helicopter). The decision as to what form of transport to use will depend on:

• the condition of the patient

• the potential impact of the transport medium on the patient

• the distance to be covered

• the urgency of the transport

• the environmental conditions

• the resources available

• the expertise of the respective transport teams.

Amenities such as landing sites, particularly for helicopters, being in close proximity to healthcare facilities must also be considered. Different jurisdictions activate air retrieval using helicopters when the distance for the transport is beyond a certain point, with the minimum distance ranging from 16–80 km.^14,^15,^19,²⁰

It is essential that the standard of care is not compromised during transport of critically injured patients. Minimum standards exist that outline the requirements for transport of critically injured patients, and these should be referred to for full details.^13,^18,¹⁹ The following principles apply during such phases of care:

• There must be adequate preparation of the patient and equipment.

• Transport must occur by personnel with appropriate levels of expertise.

• Necessary equipment, including batteries and pumps, should be secured.

• Patients should be stabilised prior to transport (whilst balancing the need for timely transport).

• Monitoring of relevant aspects of the patient’s care is essential.

• Adequate vascular access and airway control must be secured prior to commencing transport.

• Effective communication is mandatory between referring, transporting and receiving personnel.

• Documentation, including X-rays and scans, should accompany the patient and should cover the patient’s status, assessment and treatment before, during, and on completion of, the transport.

• Relatives should be informed of the transfer, including destination, and provided with assistance for their own travel arrangements.¹⁸ Checklists itemising many of these principles, sometimes attached to an envelope containing all transfer documentation, are often used to ensure that all necessary actions are undertaken.²⁰

Trauma Reception

Reception of the trauma patient at the emergency department of the hospital is generally performed by the triage nurse, although in the severely injured patient it is usual for a multidisciplinary team to receive the patient and commence assessment and treatment concurrently. In the setting of a mass-casualty incident, triage may be performed in the field.

The formal process of triage provides a means of categorising patients based on threat to life. Although there are many different triage systems in use, within Australia and New Zealand, the five-level triage categorisation of the Australasian Triage Scale (ATS) is widely used.²³ See Chapter 22 for further description of the ATS.

Primary Survey

Priorities of care are similar to those in all health settings, with airway, breathing and circulation taking precedence, and disability and exposure/environment being part of the primary survey (see Chapter 22). These components of care will often occur simultaneously rather than sequentially. Compromise to airway and breathing may result from direct injury, for example to the trachea, or indirectly through decreased level of consciousness. Compromise to circulation is usually as a result of significant blood loss, although it may occur as a result of injuries, such as cardiac contusions in chest trauma, or the patient’s preexisting disease. The priorities of care during this time reflect the principles of care in any setting, and include:

• maintaining life, with priority given to airway, breathing and circulation

• treating immediate problems such as bleeding

• preventing complications or further compromise.

Secondary Survey

Following stabilisation of the life-threatening problems identified during the primary survey, patients should undergo a secondary survey (see Chapter 22). This is a systematic examination of the body regions to identify injuries that have not yet been recognised. It is essential that both the front and the back of the patient, as well as areas covered by clothing, are examined during this process.

Tertiary Survey

A tertiary survey should be conducted on, or soon after, the arrival of trauma patients in the ICU. The purpose of this third survey is to identify injuries that have not yet been detected, assess initial response to treatment and plan assessment and management strategies for future care.

The tertiary survey consists of another head-to-toe physical examination, assessment of the patient’s condition in the context of his/her earlier condition and the treatment that has been administered, a full review of all diagnostic information gained so far, and acquisition of the patient’s past health history if family members or friends are available. A systematic approach will minimise the number of injuries that are not identified during the first 24 hours of care. It is also important to repeat the tertiary survey after the patient regains consciousness and begins to mobilise. Joint injuries may only become apparent during weight-bearing movements.

Radiological and Other Investigations

Initial radiological investigations will usually be performed in the emergency department using portable equipment. A radiographer is often a member of the trauma team that is activated on notification of the imminent arrival of a severely-injured trauma case. Radiological investigation will be dependent on the type of injury sustained, but will generally consist of a portable X-ray of the injured area/s if these include the chest, cervical spine or pelvis. Other X-rays at this stage are rarely beneficial, or rarely change the course of treatment.

If the patient is sufficiently stable after the secondary survey, more extensive investigation in the radiology department should be undertaken. This will include CT scans. It is essential that clinicians consider investigations carefully, to ensure that all necessary imaging is undertaken; for example, where a CT scan of the brain is required it is often prudent to also undertake a CT scan of the cervical spine. However care should be taken to avoid investigations that will not change the planned treatment but may delay urgent interventions such as surgery. Current controversies in radiation exposure and lifetime-associated cancer risks need to be considered.²¹ Furthermore, the implications of moving the patient on and off imaging tables for repeated imaging is problematic. The patient should be accompanied and monitored by an appropriately competent nurse during all transfers for investigation. Where the patient is requiring ongoing advanced life support such as fluid resuscitation or airway monitoring, it may also be appropriate for a medical officer to accompany the patient.

Further radiological investigation may be required as part of the tertiary survey. This will depend on the radiological examinations that have been undertaken as part of the secondary survey, the treatment that has already been administered and the current condition of the patient.

Focused assessment with sonography for trauma

Where abdominal trauma is suspected, a focused assessment with sonography for trauma (FAST) examination ^22,²³ is likely to be used as part of the secondary survey to determine whether free fluid is present in the abdominal cavity. The abdomen is scanned in four zones – pericardial, Morison’s pouch (right upper quandrant), splenorenal (left upper quadrant), and pelvis (Douglas’ pouch). This generally takes 1–2 minutes when performed by an experienced, credentialled clinician. Findings are regarded as positive (fluid [blood] observed), negative or equivocal. Technical difficulties can be experienced with obese patients. While a positive FAST is useful in identifying if a patient should receive urgent surgical intervention, a negative FAST does not rule out significant abdominal trauma, and the low sensitivity of FAST remains a concern for trauma clinicians.²² Where a patient is undergoing a prolonged trauma resuscitation phase, there may be an indication to repeat the FAST after 20 minutes. The use of FAST examination outside the trauma resuscitation and reception phase is occurring more often and can be undertaken in any clinician setting where there is a suspicion of internal haemorrhage or pneumothorax.²⁴

Trauma Teams

There are a number of different ways to organise the early care of trauma patients. The most common method used is through the establishment of multidisciplinary trauma teams that can provide immediate, expert assessment, resuscitation and treatment of traumatised patients, especially those with multiple injuries. Many hospitals that receive trauma cases operate trauma teams that are either activated or placed on standby, via pagers or telephone, based on communications from paramedic personnel in the prehospital setting.²⁵ This activation is based on a combination of physiological and injury criteria (see Table 23.1). Age is sometimes added to the patient criteria, with those under 5 years or over 65 years receiving particular attention. A number of hospitals have two levels of trauma team activation, with more severe injuries activating the full trauma team and less severe activating a partial team. The use of two-tiered trauma team activation has not been shown to affect patient outcomes.¹⁷

TABLE 23.1 Criteria for activation of trauma teams ^26,²⁷

Physiological criteria	Injury criteria
Heart rate <50 or >120 beats/min Respiratory rate <10 or >29 breaths/min Systolic blood pressure <90 mmHg Glasgow Coma Scale Score <10 Skin pale, cool or moist Paralysis Trauma arrest	Penetrating injury to head, neck or torso Burn to ≥20% body surface area Fall ≥5 metres Multiple trauma Crush or degloving injury to extremity Amputation proximal to the wrist or ankle Motor vehicle crash with ejection

Common Clinical Presentations

Trauma generally occurs to a specific area of the body (e.g. the chest or the head) or consists of an injury caused by a specific external cause (e.g. burns). This section has been arranged according to these specific types of injury, including skeletal, chest, abdominal and from burns. Specific considerations relating to penetrating injuries have been covered separately, although the majority of care for patients with penetrating injuries will follow the principles of the area for injury. For example, a patient with a penetrating injury of the abdomen will generally be cared for in the same way as all patients with abdominal trauma.

Patients with multitrauma will also be cared for according to the principles of care for each specific injury, although consideration of priorities is essential. Care should follow the common principles of airway, breathing and circulation, therefore concentrating on respiratory and circulatory compromise first, before moving on to the treatment of other injuries. The relative importance of other injuries, for example neurological trauma or skeletal trauma, will vary for each individual patient and will be dependent on the physiological impact of the injuries. Neurological and spinal cord injury are reviewed in Chapter 17.

Mechanism of Injury

The most common causes of traumatic injury include road traffic crashes, falls and collisions. While falls account for the greatest number of injuries requiring hospitalisation,²⁸ injuries sustained in road traffic crashes tend to be more severe given the high velocity of the trauma, and account for the greatest number of major injuries, including those injuries requiring a critical care admission.²⁸^–³⁰

The mechanism of injury is recognised as affecting both survival and requirement for admission to the intensive care unit. Patients who are injured in a road traffic crash experience a similar mortality to those injured through falls (approx 3% in all patients and 10–17% in major injury patients), with both groups having a higher mortality than patients injured in assaults and collisions with objects (<1% in all patients and 12% in major injury patients).^28,²⁹ The older age group, with associated comorbidities, is likely to account for many of the deaths in the group injured through falls. In addition, patients injured in road traffic crashes tend to spend longer in the intensive care unit than patients injured through falls or assaults and collisions, and experience a greater number of injuries.²⁸

Generic Nursing Practice

Nursing care of trauma patients is characterised by the need to integrate practices directed towards limiting the impact of the injury and healing injuries to multiple body areas in a complex process. The delivery of critical care services must be systematic and must cross departmental and team barriers to achieve a coordinated approach. This section outlines the principles of care relevant to all trauma patients, including positioning, mobilisation, and prevention or minimisation of the trauma triad components of hypothermia, acidosis and coagulopathy.

Positioning and Mobilisation of the Trauma Patient

Appropriate positioning and mobilisation provides a significant challenge for nurses involved in the acute care of the trauma patient. Positioning refers to the alignment and distribution of the patient in the bed, for example supine, Fowler, semirecumbent or prone. In addition to these fundamental nursing postures, there is positioning of the limbs (i.e. elevated arms and legs). Mobilisation refers to the movement of joints by the patient, to shift from one place to another. This movement may be restricted to rolling within the bed, or moving out of the bed.

The principles of positioning and mobilisation are generally not different from those in other critically ill patients, and should incorporate the need to:

• promote the patient’s comfort

• maintain the patient’s and staff members’ safety

• prevent complications

• facilitate delivery of care.

Difficulty in positioning and mobilisation is often experienced when there is concern for the stability of the patient’s cervical spine, particularly in unconscious patients. Specific protocols for confirming the absence of injury to the cervical spine in unconscious patients, or those complaining of cervical soreness or abnormal neurology, vary between institutions and regions, but generally incorporate the following principles:³¹

• Obtain a detailed history of the injury wherever possible, including specific investigation of mechanisms of injury that might exert force on the cervical spine. A high index of suspicion should remain, particularly in the setting of injuries often associated with cervical spine injury, including craniofacial trauma rib fractures, pneumothoraces and damage to the great vessels and/or trachea.

• Undertake plain X-rays of the full length of the spine, interpreted by a radiologist.

• Where any abnormality exists in clinical or radiological assessment, or the patient remains unconscious, a CT or MRI may be undertaken, and this must be reported on by a radiologist.

• A correctly fitted hard collar should remain in place only until the patient is appropriately reviewed and the chance of a cervical spine injury is eliminated. If a collar is required for more than 4 hours, a long-term collar (e.g. Philadelphia, Aspen or Miami J) should be used.

• Maintain appropriate pressure area care to areas under the hard collar as well as usual pressure points until cervical clearance is gained.³²

The practice of maintaining a patient in a hard collar for days without active attempts to gain cervical clearance should be avoided at all costs.

The two methods available for moving the trauma patient are staff manual handling and lifting hoists. Generally, trauma patients can be log-rolled (see Figure 23.1 for initial care and p. 635 for later care) as frequently as required for nursing care. Any restrictions to patient positioning and weight bearing due to injuries or physiological status must be considered through this process; it is essential that care be taken to prevent any worsening of injuries due to handling of the patient. Knowledge of the position restrictions for each limb, including all weight-bearing joints and the vertebrae, is imperative to avoid secondary iatrogenic injury. Certain injuries will impose position and mobility restrictions (see Table 23.2).

FIGURE 23.1 Spine Movement Precautions.⁷⁸

TABLE 23.2 Position and mobility restrictions in trauma patients

Type of injury	Restrictions
Traumatic brain injury	• Nurse head up 15–30 degrees. • Side-lying as tolerated. • Full tilt on bed if cervical spine not yet cleared of injury. • Occasionally nursed flat if ICP problematic.

Facial trauma

• Generally nurse in head-elevated position to reduce swelling, using either full bed tilt or back rest elevation.

Chest trauma

• Nurse in varying positions from semi-Fowler to side-lying.

• Postural drainage (head down) usually beneficial if not contraindicated by other injuries (e.g. head or facial).

Abdominal trauma

• Nurse in varying positions from semi-Fowler to side-lying.

• Preferable to have some degree of hip flexion when lying supine to reduce abdominal suture line tension.

Pelvic trauma

• Position restrictions are dependent on severity of fracture(s), use of external fixateurs and degree of stabilisation.

• Some patients may sit out of bed and ambulate with external pelvis fixateur in situ.

• Position restrictions require regular review, as changed or loss of fixation may affect recovery.

Extremity trauma

• Significant position restrictions may include limb elevation, avoidance of side-lying or limited movement.

ICP = intracranial pressure.

Practice tip

When planning positioning and mobilisation of the trauma patient, ascertain the weight-bearing status of each injured limb, then determine positions or methods of mobilisation that are appropriate.

Practice tip

The NEXUS low-risk criteria have been widely accepted as identifying patients in whom further examination is unnecessary and cervical spine injury can be excluded on the basis of clinical examination.⁸² These criteria include absence of midline cervical spine tenderness, no focal neurological deficit, no intoxication, no painful distracting injury and normal alertness.

The ‘Trauma Triad’

The critically injured patient can experience the ‘trauma triad’ of hypothermia, acidosis and coagulopathy. While it is possible to experience these pathophysiological conditions individually, they often occur simultaneously. Additionally, hypothermia is a common contributor to the exacerbation of both acidosis and coagulopathy.³³^–³⁸ Acidosis has been discussed in earlier chapters so is reviewed here only as it interacts with hypothermia and coagulopathy in the trauma setting. Low cardiac output, hypotension, hypoxia, hypothermia and rhabdomyolysis are common causes of acidosis in the trauma setting. The increased recognition of the importance of this triad in the trauma setting has led to the development of damage control surgery. The principle of this surgery is reviewed below.

Hypothermia

Hypothermia is defined as a core temperature <35°C and is associated with high morbidity and mortality. Even in sub-tropical environments, hypothermia is identified in approximately 10% of major trauma cases during the prehospital or in-hospital phase of care.^36,³⁹

Uncontrolled causes of hypothermia can be endogenous or accidental.^33,^34,^37,³⁹ Endogenous causes include metabolic dysfunction with decreased heat production, or central nervous system dysfunction with insufficient thermoregulation such as in neurological trauma. Dermal dysfunction, such as a burn, is another endogenous cause of hypothermia.

Accidental hypothermia can occur without thermoregulatory dysfunction, and generally occurs in the trauma patient as a result of environmental exposure either at the injury site or during transport to, or between, healthcare facilities, as a result of large-volume fluid resuscitation or during prolonged surgical procedures. The pathophysiological changes associated with hypothermia vary depending on the severity, and are outlined in Chapter 22. Of particular relevance, shivering leads to increased oxygen consumption and acidosis, and platelet dysfunction leads to impaired clotting.^33,^36,³⁹

Measures to reduce the incidence of hypothermia – or to correct it when it is present – in the trauma setting include:

• ensuring the patient is adequately covered during transport and hospital care

• warm intravenous fluids

• using warm blankets or electrical warming blankets

• adjusting the temperature in the operating room where feasible.³⁹

In extreme cases of hypothermia internal methods of rewarming, such as cardiopulmonary bypass and peritoneal dialysis or lavage, might be utilised.

Coagulopathy

Coagulation is widespread in the trauma setting, and ranges from a mild defect in coagulation function to life-threatening coagulopathy. Defects in coagulation may be caused by dilution, hypothermia, acidosis, tissue damage or the effects of underlying disease.^34,³⁵

Dilution results from the transfusion of either crystalloid or colloid fluids, and occurs as the concentration of coagulation factors in the patient’s blood is diluted with the transfused fluid. It should be remembered that transfusion of red blood cells has the same effect, as whole blood or packed cells have undergone some dilution and have reduced viability of platelets.³⁸ Hypothermia causes coagulopathy because many of the enzymatic reactions in coagulation are temperature-dependent. Platelet and thromboplastin function both decline with even moderate (34°C) hypothermia, while hypothermia stimulates fibrinolysis.^34,⁴⁰

Acidosis reduces the activity of both the extrinsic and the intrinsic coagulation pathways, as well as platelet function. This is particularly pronounced with a pH below 6.8.³⁴ Tissue damage causes endothelial disruption and defibrination, which promote the systemic activation of coagulation; this is particularly profound in patients with brain injury due to the high level of thromboplastin in brain tissue.^34,^37,³⁸ The final cause of coagulopathy in trauma is the underlying disease present in many patients. Patients may have a coagulation defect such as haemophilia or von Willebrand’s disease, or liver disease with resultant compromise to coagulation on an ongoing basis. Alternatively, patients may be taking anticoagulants, such as aspirin or warfarin, as treatment for other health conditions.^37,⁴¹

Treatment of coagulopathy should focus first on prevention of coagulopathy and then on the treatment as required. Prevention strategies include:⁴⁰

• maintaining normothermia in critically injured patients through the use of blankets, warming devices, and minimisation of exposure and theatre time

• administering as little resuscitation fluid as is necessary to maintain adequate circulation

• achieving control of haemorrhage as soon as possible, through techniques such as low-pressure resuscitation and damage-control surgery.

There is a strong need to ensure that patients are not overtransfused, and regular monitoring of coagulation factors including haematocrit, platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen levels will assist in achieving this aim. The international normalised ratio (INR) should be measured at the beginning of the process and repeated if abnormal.

Treatment includes transfusion of platelets, fresh frozen plasma (FFP) and cryoprecipitate, as well as the plasma derivatives showing promise in this area of treatment.³⁵ While transfusion of platelets is specifically directed towards increasing the circulating concentration of platelets, administration of FFP is directed at increasing the levels of fibrinogen and other coagulation factors. Cryoprecipitate is made by freezing and thawing individual units of FFP and collecting the precipitate, a process that concentrates fibrinogen, von Willebrand factor, factor VIII and factor XIII.

Damage-control Surgery

Damage-control surgery can be defined as a four-stage procedure, involving early recognition of relevant patients and ‘rapid termination of an operation after control of life-threatening bleeding and contamination followed by correction of physiological abnormalities and definitive management’.^42,⁴³ This approach to surgical correction of traumatic injuries gained favour through the latter part of the 1990s and is intended to reduce the development of the triad of complications of hypothermia, acidosis and coagulopathy. The intention is that surgery is initiated rapidly, only the most rapid and simplest interventions that are required to stop bleeding and contamination are undertaken, then surgery is completed and the patient moved to definitive care, usually in the ICU.⁴² Care can then be undertaken to ensure that hypothermia, acidosis and coagulopathy do not develop or, if present, are rapidly reversed, thereby ensuring correction of physiological abnormalities as quickly as possible. Definitive surgical correction of injuries is undertaken during the ensuing days when the patient is physiologically stable. Damage-control surgery can apply to a range of patients, including those with abdominal, skeletal and thoracic trauma.

Nursing a patient who undergoes damage-control surgery requires recognition of the principles and aims of the surgery, as well as flexibility in care of the patient after the initial surgery but before definitive surgery. In the emergency department setting there is a need to undertake a rapid, systematic evaluation of the patient and prepare him or her for rapid transfer to the operating room. It is essential to implement all measures possible to preclude the components of the trauma triad, while avoiding any delays to surgery. When the patient is admitted to the ICU postoperatively, the standard mechanisms for the treatment of hypothermia, acidosis and coagulopathy, as discussed above, should be implemented. After damage-control surgery, patients may also have an open abdomen with temporary dressings, or skeletal fractures with external fixateurs in situ.

Skeletal Trauma

Skeletal trauma involves injury to the bony structure of the body. While skeletal injuries alone rarely result in the patient being admitted to critical care, damage to surrounding blood vessels and nerves, as well as potential complications such as fat embolism syndrome (FES) and rhabdomyolysis, may cause the patient to become seriously ill. Patients with skeletal trauma who require admission to ICU include those with multiple injuries, severe pelvic fractures (often associated with significant blood loss), long bone fractures (often associated with FES) and thoracic injuries such as flail segment. A small number of people with crush injuries that cause significant damage to muscles, often resulting in rhabdomyolysis, also require admission to the ICU.^44,⁴⁵

Skeletal trauma is the form of trauma that causes the highest number of patients to be admitted to hospital for 24 hours or more, with approximately 50% of patients experiencing a fracture as their main injury.²⁸ Of those patients admitted to an ICU, fractures are the second most common type of injury (after head injury), with approximately 20% of patients experiencing this type of injury.

Pathophysiology

Bone is composed of an organic matrix as well as bone salts. The majority of the organic matrix is collagen fibres and the remainder is ground substance, a homogeneous gelatinous medium composed of extracellular fluid plus proteoglycans.⁴⁶ Calcium and phosphate are the primary bone salts, although there are smaller amounts of magnesium, sodium, potassium and carbonate ions. These ions combine to form a crystal known as hydroxyapatite.

A fracture is simply defined as a break in the continuity of a bone. Fractures generally occur when there is force applied that exceeds the tensile or compressive strength of the bone. In patients sustaining a major injury (injury severity score [ISS] ≥16) fractures are the primary injury in more than 15% of cases, although many patients experience a fracture in addition to other serious injury resulting in ICU admission.²⁸

Fractures are classified as either complete or incomplete. A complete fracture is where the bone is broken all the way through, while incomplete fractures only involve part of the bone. Fractures are also classified according to the direction of the fracture line, and include linear, oblique, spiral and transverse fractures.

A fracture causes disruption to the periosteum, blood vessels, marrow and surrounding soft tissue, resulting in a loss of mechanical integrity of the bone. Bone is one of only two sites (the other being the liver) that will reform itself, not forming scar tissue when it heals.⁴⁷ When a fracture occurs, there is initial bleeding and soft tissue damage around the site, with haematoma formation within the medullary canal. The healing sequence that follows a fracture depends on the type of fracture fixation that is used. When a fracture is fixed in a method that eliminates the interfragmentary gap and provides stability to the site, such as in screwing or wiring, primary healing takes place. When a fracture is fixed in a manner that reduces but does not eliminate movement around the fracture site, secondary healing takes place.⁴⁸

In primary healing, also referred to as direct union, the haematoma that initially formed is eliminated by the apposition of fracture ends during reduction. Once the bone ends are intact, osteoclasts form cutting cones that in turn form new haversian canals across the fracture gap. These contain blood vessels that are essential to primary bone healing. By 5–6 weeks after the fracture, osteoblasts will fill the canals with osteons, which are the basic structure of the new bone.⁴⁷ Although the bone is now formed, the strength and shape continues to develop over coming weeks.

In contrast to primary healing, secondary healing is characterised by an intermediate phase, where a callus of connective tissue is first formed and then replaced by bone.^47,⁴⁹ The secondary healing phase begins with an inflammatory phase in which the haematoma clots and provides initial support, then inflammatory cells invade the haematoma to remove necrosed bone and debris. The reparative phase begins 1–2 weeks after the fracture and consists of immature woven bone being laid down and strengthened through a process known as mineralisation. The final remodelling stage consists of replacement of the woven bone by lamellar bone, through osteoblasts secreting osteoid that is mineralised and forms interstitial lamellae. The remodelling of these structures occurs in response to appropriate levels of mechanical loading during this phase.^47,⁴⁸

Fat embolism

Fat embolism syndrome (FES) may occur in patients who have experienced a fracture of a long bone, particularly if multiple fractures or fractures to the middle or proximal parts of the femur are experienced. Fractures to the pelvis can also lead to a fat embolism. Incidence of FES is low (<1%). FES consists of fat in the blood circulation associated with an identifiable pattern of clinical signs and symptoms that include hypoxaemia, neurological symptoms and a petechial rash.⁴⁹ Patients generally present 12–48 hours after they have experienced a relevant fracture and often require admission to a critical care unit for assessment and treatment, including mechanical ventilation.

Internationally, there continues to be disagreement regarding the pathophysiological changes associated with FES, although there is general consensus on the following principles. It has been accepted that there is a mechanical component to the changes that take place in FES, where fat is physically forced into the venous system and causes physical obstruction of the vasculature. Although marrow pressure is normally 30–50 mmHg, it can be increased up to 600 mmHg during intramedullary reaming (the process where the medullary cavity of the bone is surgically enlarged to fit a surgical implant such as a tibial nail), consequently reaching a pressure significantly above pressures throughout the vasculature.⁴⁹ A second theory, associated with the biochemical changes that occur during trauma, proposes that trauma is associated with a higher level of circulating free fatty acids, which cause destabilisation of circulating fats and/or direct toxicity to specific tissues, including pulmonary and vascular endothelium.⁴⁹

Rhabdomyolysis

Rhabdomyolysis is the breakdown of muscle fibres resulting in the distribution of the cellular contents of the affected muscle throughout the circulation, and occurs during the reperfusion of injured muscle. The cellular contents that are circulated include potassium, phosphate, organic acids, myoglobin, creatine kinase and thromboplastin.⁴⁴ Two phases of injury are essential for the development of rhabdomyolysis: the first is when muscle ischaemia occurs, and the second is with reperfusion of the injured muscle. The length of time that muscle is ischaemic affects the development of rhabdomyolysis, with periods of less than 2 hours generally not producing permanent damage, but periods above this time resulting in irreversible anatomical and functional changes.⁴⁴ The clinical sequelae of rhabdomyolysis include electrolyte abnormalities such as hypocalcaemia, hyperkalaemia and acidosis, hypovolaemia, acute renal failure and multiorgan failure.

Clinical Manifestations

Common forms of skeletal trauma include the following:

• Long bone fractures. The long bones are the humerus, radius, ulna, femur, tibia and fibula. Fractures of these bones are serious and can carry a high level of morbidity, especially if they involve a joint such as a trimalleolar fracture of the ankle (distal tibia and fibula). In many cases definitive surgical management is required, with internal fixation.

• Dislocations. All joints are at risk of traumatic dislocation, depending on the mechanism of injury. Dislocations can be limb-threatening if they cause neurovascular compromise. Reduction of traumatic dislocation is a medical emergency.

• Open fractures (compound). Any break in the skin that communicates directly with the fracture is classified as an open fracture. Open fractures carry a higher infection risk and require surgical treatment within 8 hours.^50,⁵¹

• Traumatic amputation. Amputation refers to an avulsion in which the affected limb or body appendage is completely separated from the body. This can occur when a digit or extremity is sheared off by either mechanical or severing forces, for example amputation of a thumb by a bandsaw. Traumatic amputations vary in severity and ongoing compromise, with a cleancut amputation more likely to be successfully reattached than a crushed extremity. Criteria that inform the surgical decision-making process include the amount of tissue loss, location on the body at the connection site, damage to underlying and surrounding tissues, bones, nerves, tendons/muscles and vessels, and condition of the amputated part.

• Fractures of the pelvis. The pelvis is the largest combined bony structure in the body and serves to provide an essential supporting framework for ambulation and protection of pelvic organs. Major blood vessels and nerves traverse the pelvic bones, supplying the lower limbs and pelvic organs. Therefore, injury to any part of the pelvis is serious. The three bones that comprise the pelvic ring are the two innominate bones (ilium and pubic rami) and the sacrum. Due to its reinforced structure, the amount of force required to fracture the pelvis is substantial. Fractures of the pelvis can affect one or both sides of the pelvis, and be stable or unstable. A variety of classification systems exist to describe the severity of pelvic fractures, the most common being the Tile classification (see Figure 23.2).

• Fractures of the spinal column. (see also Chapter 17). The spinal column includes all of the bony components in the cervical, thoracic and lumbar vertebral regions. Fractures of the vertebra are common in trauma patients, but the actual incidence of fracture without spinal cord injury in multitrauma patients is not well described. Not all fractures cause vertebral column instability with the subsequent risk of spinal cord damage. A spine column fracture will be diagnosed as mechanically stable or unstable and this will affect the positioning and possible activity of the patient.

• Discoligamentous injuries of the spinal columns (see also Chapter 17). The soft tissue components of the spinal column include the spinal cord, the inter-vertebral discs and the spinal ligaments. An injury to the spinal column can disrupt one or more of these structures with or without fracture. These injuries can be highly unstable and the nurse must be vigilant with spinal precautions and the fitting and management of the patient requiring a spine orthoses (refer to Figure 23.1).

FIGURE 23.2 Tile classification for pelvic fractures.⁷⁹

Nursing Practice

There are several major considerations for the nurse managing the critically ill patient with skeletal trauma. These include appropriate assessment as well as application of traction, management of any amputated parts and stabilisation of pelvic fractures and spine precautions. These latter aspects of care will be conducted in collaboration with medical and allied health colleagues.

Independent practice

Bones are very vascular structures and can be the cause of substantial blood loss in the trauma patient. The critical care nurse should therefore be cognisant of the potential for extensive blood loss in common fractures (see Table 23.3).

TABLE 23.3 Potential blood loss caused by fractures ⁷⁶

Fracture	Blood loss (mL)
Humerus	500–1500
Elbow	250–750
Radius/ulna	250–500
Pelvis	500–3000
Femur	500–3000
Tibia/fibula	250–2000
Ankle	250–1000

Given the potential for extensive blood loss, as well as the frequent close proximity of nerves and blood vessels to bones, neurovascular assessment of the patient with skeletal trauma is essential (see Table 23.4).

TABLE 23.4 Neurovascular observations of the skeletal trauma patient
Should be undertaken on all injured limbs both pre- and postoperatively as required

Observation	Process	Comments
Skin colour	State the skin colour of the area inspected as it compares with the unaffected part. NB: Distal limb pulses may be difficult to palpate in the injured limb; a warm pink limb is a perfused limb.	Pink: normal perfusion
		Pale: reduced perfusion
		Dusky, purple or cyanotic discolouration: usually indicating significantly reduced perfusion
		Demarcated: a distinct line where the skin colour changes to dusky (usually follows the vessel path)
Skin temperature to touch	State the ambient temperature of the skin to touch as it compares with normally perfused skin at room temperature.	Normal: not discernibly cold to touch. Reduced skin temperature indicates reduced perfusion.
Voluntary movement	The patient should be able to move the non-immobilised distal part of any injured limb (i.e. fingers and toes of a plastered limb).	It is important to assess range of motion where that is possible, provided this will not aggravate the injury. Reduced movement may indicate compromise to either the nerve or blood supply to the limb.
Sensation	The patient should be able to report normal sensation to touch.	Sensation should be assessed in nerve distributions (i.e. all fingers and toes). Reduced sensation may indicate compromise to either the nerve or blood supply to the limb.