Introduction

Field hospitals will invariably be deployed in situations in which the medical needs far exceed the surge capacity of the local medical facilities. Most deployments will be either following major natural disasters such as earthquakes, storms and floods, human-made disasters – armed conflicts or industrial accidents – widespread epidemic outbreaks and large-scale refugee migrations[1–5]. Deployments may be short or long term, and the field hospital will treat large numbers of patients with pathologies resulting from the event as well as routine medical problems in the local population – serving as a supplement or substitute to the local medical system[6]. Most deployments will be in low- and middle-income countries in which the baseline of medical services is suboptimal during routine times and is further challenged by the calamity.

As a result of this situation, the prime factor in the operational scenario of a field hospital, when compared to a permanent hospital operating in routine conditions, is an extreme imbalance between the medical requirements and the ability to deliver adequate care to as many patients as possible. The need to diminish this imbalance will dictate the operational principles at all service levels.

While the above “principle of imbalance” is pertinent in all fields of medicine within the field hospital, its relevance is increased tenfold in the field of orthopedics. This is true because of increased needs as well as diminished ability to deliver care.

The orthopedic needs vary widely depending on the operational scenario. However, the two most common situations in which field hospitals are deployed – following major earthquakes and during armed conflicts – produce large numbers of complex injuries requiring a long series of surgeries with subsequent rehabilitation. On the other side of the imbalance scale is the ability to deliver care. Whereas many of the medical and surgical specialties require only basic diagnostic and therapeutic equipment, enabling the caregiver to deliver an adequate standard of care under austere conditions or in a prehospital facility, the situation in orthopedics is very different. At the diagnostic level, the minimal requirement is an X-ray machine producing basic radiographs. X-ray capability, although required by the World Health Organization (WHO) standards in all field hospitals[7], may sometimes be unavailable. Moreover, in some areas of the body, three-dimensional imaging (CT or MRI) is essential to make an accurate diagnosis and these modalities are currently unavailable in the field-hospital setting. This limited diagnostic capability will directly influence the type and level of care that can be delivered in a field hospital. At the therapeutic level, there are two major problems preventing delivery of a standard of treatment that parallels that given in a full-service permanent hospital:

1. Modern orthopedic treatment utilizes an amount and diversity of equipment unparalleled in any other surgical field. This is true of surgical instruments, but more so of hardware and implants utilized for fracture fixation and limb reconstruction, while unsalvageable joints are currently treated by partial or total joint replacement; requiring a large armamentarium of implants. The logistic reality of a field hospital deployment will enable availability of only a very limited hardware stock.

2. The skeletal system’s susceptibility to infection and the extreme difficulty in treating these infections, once established, dictate the need to perform orthopedic surgical procedures under severe aseptic conditions. These conditions are unattainable in most field hospitals.

Both these factors dictate an extreme change in the paradigm of orthopedic treatment in a field hospital when compared to that practiced in a regular hospital in a high resource country.

Deployment Scenarios

The factors governing the orthopedic needs during field hospital deployment include the following:

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   1. The type of event prompting deployment. Scenarios prompting field hospital deployment include natural disasters and human-made calamities. Among natural disasters, earthquakes cause the highest number of musculoskeletal injuries requiring orthopedic treatment[8–10]. The reason lies in the nature of the disaster. The energy released during an earthquake is unequalled in any other event. Most of the energy released is mechanical energy, causing collapse of buildings, and most injuries are caused by falling debris resulting in fractures, soft tissue wounds, and crush injuries. The number and type of injuries will therefore depend on the magnitude of the earthquake, the level of urbanization, the type and quality of building, and the time of day of the occurrence. Additional causes of musculoskeletal injuries during earthquakes include falling or jumping from heights, falls during escape, and burns due to fires erupting during the earthquake. In natural disasters such as tsunamis, storms, and floods, despite a high number of people killed in the disaster, the number and severity of injuries will be much lower than in an earthquake[1,11–13]. However, common to all disaster scenarios, musculoskeletal injuries will predominate as the leading cause of morbidity.

   
   

   In armed conflicts, the types of injuries encountered will depend on the nature of the conflict and the types of weaponry used. These range from traditional weapons such as machetes and small arms, to antipersonnel or antitank landmines, and heavy weaponry such as artillery and air bombardment[14–19].

   
   
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   2. The phase of the deployment in the timeline following the event. Field hospitals will typically not start operating before day four following the event. Therefore, patients sustaining life-threatening internal or multiorgan injuries will either have perished or will have been treated in local facilities. Field hospitals deployed in the first weeks following the disaster will encounter acute injuries, followed by early complications; mainly infections and the consequences of crush injuries. Subsequent deployments will encounter late complications: chronic infections, nonunion, malunion, and rehabilitation problems[1,20].

   
   
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   3. The capabilities of local medical facilities and adjacent emergency medical teams (EMTs) in the disaster zone, as well as the capabilities of medical facilities outside the disaster zone, and the evacuation capabilities to these facilities. These factors, together with the level of coordination in the EMTCC and health cluster managing the disaster, will directly affect the caseload encountered in the field hospital. The caseload will also be affected by the baseline capabilities of the local medical system and the health status of the population prior to the disaster[3,21–24].

Injury Epidemiology

The epidemiology of injuries encountered in field hospitals will vary according to the deployment circumstances. However, in all cases it will be very different from that found in everyday practice. The musculoskeletal injuries encountered following earthquakes and armed conflicts will be mostly high energy injuries. In earthquake deployments, 60% of patients treated due to trauma will suffer limb injuries. Nineteen percent of all patients treated and 54% of those admitted will have fractures, and 31% of these fractures will be open. Lower limb fractures predominate (62%), followed by upper limbs (23%) and axial skeleton injuries (14%)[3,9,20,25–39].

2%–5% of those injured and 12%–25% of hospitalized patients will develop crush syndrome[40,41].

In armed conflict zone deployments, 50%–75% of injuries encountered will be limb injuries; 60%–80% of them to the lower limbs. Thirty-nine percent will have fractures; 50% of them open[14–19]. The injury patterns will depend on the nature of the conflict, the populations involved (military vs civilian), and the type of weaponry used. Assault rifles utilized in close combat will cause single or multiple localized injuries. Shelling and bombing will inflict multiple superficial or deep complex wounds caused by fragments. Antipersonnel mines will inflict blast injuries and traumatic amputations of the lower limbs. Traditional cold weapons such as machetes and pangas, used in intersocietal strife, will result in slash wounds – more commonly to the upper body. The combat scenario will also induce secondary injuries caused by conventional mechanisms: falls while running, high-speed motor vehicle accidents, and injuries caused by collapsing bombed buildings. Burns may be caused by erupting fires or due to cooking in unsafe conditions in temporary habitations.

Surgical and Medical Needs

The abovementioned injury patterns dictate a wide array of surgical and medical needs. These will range from the need to treat a large number of superficial soft tissue injuries requiring basic outpatient surgical capabilities to complex limb injuries requiring major surgical procedures: fracture fixation, complex soft injury treatment and coverage, and amputations at various levels. Multisystem injuries will also require interventions and collaboration with other surgical and medical specialists. Due to the timetable of setup of field hospitals and the poor sanitary conditions prior to admission, many of the wounds encountered will be infected, requiring extensive surgical debridement and antibiotic coverage. In long-term deployments, the sequelae of the acute injuries and the rehabilitation needs will have to be addressed. In addition, patients with routine orthopedic problems will seek treatment even in the early phase following the disaster and these needs will predominate in field hospitals deployed in nondisaster scenarios[3,6,24].

Treatment Capabilities

The treatment capabilities in a field hospital will, by definition, be lower than those in a permanent medical facility. They will vary widely between the teams deployed by various governmental and nongovernmental agencies. WHO has outlined minimal standards for treatment capabilities of EMTs[7].

A type 1 EMT is not defined as a field hospital. It is a mobile or stationary team performing casualty collection and limited triage. It is capable of providing care for minor injuries and illnesses, and stabilization of more seriously injured casualties, preparing them for evacuation to a facility with higher capabilities. Orthopedic treatment capabilities will include basic wound treatment and fracture stabilization by plaster casts or splints.

Type 2 and 3 EMTs are classified as field hospitals. A type 2 facility has basic and emergency surgical capabilities and postoperative support. A type 3 EMT is an advanced field hospital with specialized multidisciplinary surgical and intensive-care capabilities. The orthopedic treatment capabilities will vary among different field hospitals, but should include musculoskeletal imaging capabilities, extended wound care, surgical fracture fixation, and amputation of unsalvageable limbs. Postoperative care, intensive medical and nursing care, and early rehabilitation should be available[8].

Facility

A field hospital should have several loci in which orthopedic care can be delivered. Initial assessment and care will be given in the triage and emergency department. The orthopedic department should be housed in a specific designated area. Wound care, closed reduction, and casting of fractures will be performed in this area. Local anesthesia can be administered, and regional blocks or conscious sedation may be available in some facilities. Outpatient care and follow-up of patients will be performed in this department[28,43].

All field hospitals will have at least one operating theater with one surgical table in type 2 and two tables in type 3 facilities. Regional and general anesthesia and appropriate monitoring will be available.

Patients requiring hospitalization will be treated in the inpatient departments. When possible, surgical patients should be in separate departments enabling specialized nursing, wound care, and pain control. Children should preferably be hospitalized in a separate pediatric ward[44,45].

Personnel

Orthopedic surgeons will be found in type 3 and possibly in type 2 EMTs. In lower-level facilities, orthopedic care will be provided by general surgeons or other health-care personnel. The number of orthopedic surgeons required will depend on the type of the disaster and the resultant caseload, and the number of orthopedists available will depend on the size of the facility and the dispatching organization. Ideally, there should be adequate orthopedic personnel to staff both the orthopedic department and the operating theater simultaneously. The orthopedic workforce can be augmented by task shifting with nonorthopedic surgeons or physicians working under the supervision of orthopedic specialists[3,8].

Nursing and paramedical staff would ideally include personnel specifically trained in caring for orthopedic patients. Practically, such personnel are scarce and will not be readily available, but onsite training is possible including wound, pin, and plaster-cast care. An orthopedic nurse should head the team in the orthopedic department, maintaining order and adequate stock management of the casting and bandaging supplies. The surgical nurses or technician team should include at least one team leader familiar with orthopedic equipment. Physiotherapists should be included in all deployments in high trauma volume scenarios to provide early rehabilitation and predischarge instruction. Due to the unique characteristics of deployment in a field hospital, especially in a postdisaster setting, all staff should undergo predeployment preparation. If there is only one orthopedic surgeon on the staff, he or she should have significant previous field experience in disasters and austere environments.

Larger teams should include personnel with previous experience as well as those exposed to the scenario for the first time to enlarge the pool of experienced personnel available for future deployments. Local health professionals and additional foreign volunteers can be incorporated into the staff, but their credentials should be scrutinized in order to ensure adequate professional standards[27,46,47].

Equipment

Surgical equipment availability, as well as the level of asepsis, will be main limiting factors in the orthopedic treatment capabilities of a field hospital. The minimal equipment set should include the following:

Power instruments (drill and saw) may be available in some field hospitals. These should be with rechargeable batteries rather than electric cable or air powered. Low-priced hardware store drills can be used, but surgical techniques will have to be modified as these are not sterilizable.

Most field hospitals will not include internal fixation in their armamentarium due to inadequate aseptic conditions in the surgical theater, as well as cost and payload considerations. Recently, some nongovernmental organizations (NGOs) have reported limited use of internal fixation in facilities in which adequate aseptic conditions have been attained[27,47–49].

C-arm fluoroscopy will rarely be included in the armamentarium of a field hospital due to price, payload, and maintenance considerations.

Treatment Principles

Treatment principles will be dictated by the deployment scenario and the capabilities of the specific field hospital. Due to all the abovementioned factors, the paradigm governing orthopedic treatment in a field hospital is completely different from that governing routine orthopedic care in a permanent hospital and will be administered according to the principles of damage control medicine, usually deferring definitive and reconstructive surgery to a permanent hospital outside the disaster or conflict area or postponing it until recovery of the local permanent facilities[50].

The first priority will be the treatment of secondary life-threatening or limb-threatening injuries. These will be usually due to massive penetrating trauma, vascular compromise, blast injuries, crush injuries, open fractures with extensive soft tissue damage, or severe infections. Although the governing principle will be “life over limb[25,51],” this principle has sometimes been misinterpreted and has led to unnecessary amputations[46]. The basic principles of a thorough assessment of the patient coupled with a recognition of the available treatment modalities and their appropriate application can lead to an optimal outcome in these suboptimal conditions.

Crush Syndrome

Crush injuries will be encountered mostly in earthquake scenarios due to injuries to the limbs caused by falling debris, with the most severe injuries being caused by prolonged entrapment under the rubble (Figure 18.1a). Besides the severe local injury to the limb with extensive soft tissue damage and possible fractures, patients may develop crush syndrome, which is a multiorgan injury with potentially life-threatening consequences. Local hemorrhage and fluid shifting will cause hypovolemic shock, hyperkalemia, and hypocalcemia, together with cytotoxin and endotoxin release, which may cause cardiac dysfunction and decreased renal blood flow; myoglobinuria and hormonal changes may lead to renal failure. Systemic treatment of crush syndrome will require intensive care and possible peritoneal or hemodialysis and therefore these patients should be treated in a type 3 EMT or in a hospital outside the disaster zone. Treatment of the local injury includes debridement of all nonviable tissues. Assessment of tissue viability will be by gross appearance, bleeding, and muscle response to diathermy[40,41,52,53] (Figure 18.1b).

Figure 18.1a Crush injury of left lower limb in patient extracted after six days under rubble

Figure 18.1b Same patient following initial debridement

Fractures

The prerequisite for modern open surgical treatment of fractures is a clean surgical environment. Although this has been achieved in some field hospitals, in most of the deployed field hospitals the absence of sterile surgical milieu, internal fixation hardware, and C-arm fluoroscopy will dictate a completely different treatment approach to fracture care. However, the basic goals of treatment remain similar: fracture reduction to an acceptable position, provision of optimal conditions for union, early mobilization when possible, and preventing complications such as infection and joint stiffness.

Open Fractures

The priority in treatment of open fractures is the prevention and treatment of infection. Therefore, initial treatment will always be debridement of nonviable and infected tissues (see chapter 17). The viability of soft tissues will be assessed by color, consistency, bleeding, and contractility. Divided nerves and tendons have traditionally been trimmed and marked for later reconstruction, but this approach has been challenged due to the introduction of a foreign body with a potential for infection. Primary repair of nerves and tendons should not be attempted. An effort should be made to preserve viable periosteum as it will induce bone formation and fracture union. Infected and devitalized bone fragments and those with no periosteal attachment should be excised. The exception is large articular osteochondral fragments, which may be cleansed and replaced for possible incorporation. Medullary canals should be inspected and curetted for contamination. Foreign bodies should be excised if they are readily accessible or if their location is potentially damaging: adjacent to neurovascular structures, intra-articular, or in weight-bearing areas. All wounds should be left open following the initial debridement and repeat debridements as described above should be performed until the wound is clean and soft tissue coverage of the bones can be achieved.

Figure 18.2a Open fracture with devitalized tibia

Figure 18.2b Same patient following several debridements, 4 cm shortening, soft tissue coverage, and external fixation

Fractures should be realigned clinically at the first debridement. The method of fracture fixation will be determined by the state of the soft tissues and the fracture configuration. In relatively small wounds, a plaster slab may be used, allowing windowing or change of the dressings for wound care. This is especially appropriate for upper limb open fractures. In injuries with more extensive soft tissue damage, either skeletal traction or external fixation should be utilized. Skeletal traction is simpler, requires only one pin, thus reducing the chance of pin tract infection, and does not contaminate the involved bone. However, the patient is immobilized in bed, requires increased nursing care, and increases hospital-bed occupancy. External fixation, although more expensive, requiring expertise and carrying a somewhat greater risk of pin tract infection, gives improved fracture stability, enables wound access, and allows early limb and patient mobilization and discharge from the hospital. It therefore remains the method of choice for fixation of open long-bone fractures in a field-hospital setting (Figure 18.2a–b). External fixators can be placed without C-arm fluoroscopy, based on clinical examination or a previous radiograph of the fracture. Self-drilling Schanz pins are preferable, but not essential, and conical threaded pins should be avoided as they cannot be backed out if necessary. Sterility of the site of pin insertion site as well as of the drill and pins must be maintained. A sterilizable power drill is preferable, but a home hardware drill can be used, maintaining sterility of the parts of the drill and pins in contact with the limb (Figure 18.3). Some protocols/NGOs will avoid using power drills due to the potential for damage in inexperienced hands and insert all pins with a hand drill[66,68,69,70].

Figure 18.3 External fixation without fluoroscopy, using a nonsterilizable home drill, maintaining sterility at pin–patient interface

The external fixator can be replaced by a plaster cast once wound closure is achieved and the fracture is stable. Alternatively, patients requiring reconstructive surgery can be converted to a circular fixator or internal fixation if required, providing adequate surgical conditions have become available[27,65,71,72]. However, when applying an external fixator, the surgeon must bear in mind that it may be the definitive treatment for the fracture in this setting. Conversion to internal fixation, although practiced in everyday settings, carries a high risk of infection and should therefore be avoided in a field hospital.

Internal fixation should never be used in an acute phase field hospital with inadequate surgical sterility. The only exception is Kirschner wires, which may be used for stabilizing fractures or dislocations in the hand or foot. Internal fixation for limited indications has been reported from field hospitals in which adequate surgical asepsis has been attained. This has mainly been intramedullary nailing of femoral fractures using the SIGN nail, which does not require fluoroscopy for insertion. Nailing of tibias is avoided due to a high infection rate[27,65].

Amputations

Although in some cases an amputation of a limb may be a lifesaving procedure, most amputations (except those of toes and some finger amputations) will cause significant long-term disability and dependency on prosthetic devices. The decision to amputate a limb will therefore be based on many factors including:

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  the general condition of the patient

  
  
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  the condition of the limb

  
  
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  the surgical capabilities in the hospital

  
  
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  the rehabilitation capabilities in the region

  
  
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  social conditions and available welfare support

  
  
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  cultural and religious attitudes to body image and mutilation in the local population

The considerations guiding the decision-making process, when compared to that in everyday practice in the high-resource countries, may be completely different in the setting of a field hospital operating in an underserved region following a major disaster or armed conflict. Several scoring systems have been devised to aid in this decision-making[73,74]. They attempt to prognosticate the chance of salvaging the limb according to various parameters relating to the injury mechanism, patient age and general health condition, and the status of the limb. They have also been used to try and forecast the probability of a patient returning to work following an amputation or limb reconstruction. These scores are based on surgical and rehabilitation capabilities in developed countries and may have to be modified for use in austere settings. However, scoring and recording the status of the limb before amputation is of ethical and medicolegal importance[75,76].

Absolute Indications

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   1. Uncontrollable sepsis. In these cases, an amputation will constitute a lifesaving procedure. However, amputation should almost never be performed as the primary procedure and the definition of a limb as a source of uncontrollable infection should be made only if systemic sepsis persists despite major debridement of all infected tissue and antibiotic coverage. One must also ensure that there is no other occult source of infection besides the limb.

   
   
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   2. Prolonged limb ischemia with irreparable vascular damage. This will depend on the time of ischemia, the degree of mutilation and the vascular reconstructive capabilities in the field hospital or the possibility of evacuating the patient to a facility with more advanced capabilities. Irreversible ischemia is the one factor that constitutes an indication for amputation in all published limb trauma scores[73].

Field Amputations

There may be situations in which the only way to extricate an entrapped person from under the rubble will be to amputate a limb. These cases are rare and controversial, but if the procedure is deemed necessary, the ethical principles of informed consent should be maintained and the amputation should be performed by personnel with adequate surgical experience. Adequate fluid resuscitation should be administered, hemorrhage control should be attainable, and adequate analgesia should be given[77] (Figure 18.4).

Figure 18.4 Patient after field amputation of the upper limb to enable extraction from under the rubble

Relative Indications

1. 
   

   1. Severe crush injuries. These may also be life threatening as mentioned above, but these effects may already be irreversible at the time of surgery and the efficacy of amputation as a lifesaving procedure in these cases remains controversial[40,41,53,54,76].

   
   
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   2. Extensive tissue loss. This may be due to the injury itself or may be the result of debridement of infected or nonviable tissues. Although some limbs may appear unsalvageable on admission, tissue loss is usually not an indication for primary amputation. Bone loss may be treated by acute shortening with planned future lengthening or intercalary bone grafts. Muscle loss and motor nerve damage can be treated by muscle transfers or arthrodesis and sensory loss at the time of injury may recover. Major skin loss can be treated with flaps or skin grafts. Unfortunately, in some past disasters, amputation has been performed too liberally by persons with inadequate experience, resulting in unnecessary physical and emotional damage, and multiple avoidable revision procedures. Although the surgical capabilities in a field hospital are inadequate for performing reconstructive procedures, they may become available in other facilities later on. Therefore, although some limb injuries will be so mutilative as to preclude any limb salvage, the decision to amputate these limbs should be taken by surgeons with experience in major limb trauma in austere settings.

   
   
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   3. Rehabilitation capabilities. An amputation through clean tissue proximal to the injured area with early closure and rehabilitation may result in an early return to the work circle and if the amputation is below the knee, the overall function may be comparable to that of a limb undergoing extensive reconstructive surgery, although longer-term follow-up studies have shown increased satisfaction in patients undergoing limb salvage. However, successful function following amputation depends on the availability of a rehabilitation system, which includes physiotherapy starting in the early postoperative stage with continued long-term treatment and capabilities of prosthetic manufacture and fitting. These capabilities must be sustainable in the long term as the prosthesis will need repair and replacement, and stumps may require future surgical care. Following the 2010 Haiti earthquake, 30% of amputees required revision surgery[78]. In addition, the amputee will require vocational training and psychologic and social support. Therefore, the availability of rehabilitative care is a prerequisite for effective amputation treatment. Lacking this care, an amputee will be severely disabled and will pose a heavy economic and emotional burden to his or her family[76].

   
   
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   4. Cultural and social considerations. The attitude to amputees varies greatly between cultures. In some, it carries a severe stigma and may add psychologic and social stress in a patient who may already be physically and emotionally challenged. Some religions sanctify the wholeness of the body and find mutilative procedures unacceptable. In addition, the economic burden of prolonged rehabilitation in an environment in which public welfare resources and support are scarce or unavailable may be devastating for the injured patients and their families. These factors may significantly affect the decision between amputation and attempts at limb preservation, sometimes at the expense of functional outcome. Therefore, the importance of informed consent following detailed explanation of the possibilities and potential outcome is essential before performing an amputation, for both ethical and medicolegal reasons. The explanation should be given not only to the patients but also to their families with the aid of an interpreter when necessary.

   
   
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   5. Surgical principles. A detailed description of the various amputation techniques is beyond the scope of this text, but the following principles should be adhered to in the field hospital setting: Initially, all viable tissues should be preserved to enable stump coverage. Stumps should be left open initially to be closed or covered as secondary procedures. Guillotine amputations should be avoided. Length should be preserved, especially in the upper limbs. Amputations through joints have the advantage of diminished bleeding. Amputations requiring bone fusion should be avoided[17,75,76].

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Chapter 6 – Training and Accreditation Chapter 3 – Definitions, Needs, Scenarios, Functional Concept, and Modes of Deployment Chapter 11 – Auxiliary Medical Services in a Field Hospital Chapter 7 – Personnel Chapter 17 – Wound Management in a Field Hospital Environment Chapter 25 – Infectious Diseases and Public Health in a Field Hospital