Transport Medicine

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225 Transport Medicine

Kate Felmet

Critically ill patients occasionally need to be moved within an institution or between hospitals. Transport of critically ill patients is a procedure with risks and benefits. Neither the nature and magnitude of risk and benefits nor the variables that might mitigate risks and maximize benefit (e.g., team training and composition, mode of transport) have been well studied. Referral patterns for many diseases, including critical illness, are evolving around centers of excellence. The structure of transport systems and the body of transport research need to keep pace. In order to realize the benefits of regionalization of critical care services, intensivists must take an active role in designing the transport systems and maintaining quality assurance. (Please note that transport issues important to the management of mass casualties in disasters are addressed in Chapter 226.)

image Risks of Transport

Risks of transport are not precisely known. The progression of underlying disease, inadequacy of care delivered during transport, or the physical stress of transport itself can all lead to clinical deterioration of the patient during transport.

The transport environment, given its limited resources and multiple distractions, is bound to be error prone. In a population-based retrospective cohort study of nearly 20,000 air-medical transports, significant adverse events (defined as death, need for major resuscitative measures, hemodynamic deterioration, inadvertent extubation, or respiratory arrest) occurred in 1 in 20 transports. Baseline hemodynamic instability and assisted ventilation before transport and duration of transport were independent predictors of adverse events.1 A retrospective review of voluntarily reported adverse events, which is likely to underestimate the true incidence, reported 11.3 adverse events occurred per 1000 flights.2 The error rate of 1.13% seems low relative to the 2.9% to 16.6% reported incidence of adverse events per hospitalization, but given that the duration of transport is measured in hours, not days, the incidence of adverse events per unit time is quite high.3

The most frequent cause of transport-related adverse events with potential for patient harm is inadequate communication.2 Communication errors are widely recognized to be a major preventable cause of morbidity and mortality in medicine in general. Because interfacility transport involves handoffs between at least three care teams, special care must be taken to ensure that critical details are transmitted. Complete documentation of all patient care records must be sent from the referring facility. Referring physicians should directly communicate the following to both the transport team and the accepting physician: (1) patient identification and medical history, (2) interventions performed during initial stabilization and the patient’s response, (3) pertinent physical examination findings, (4) ongoing therapy, and (5) complications that might occur during transport. The transport team must relay this information to the accepting physician, nurse (RN) and respiratory therapist (RT) in addition to information about the patient’s physiology and interventions performed while en route.

The incidence of adverse events in children is somewhat higher, ranging from 1.5% to 2.8% in transports with a specialized pediatric team to 20% to 61% in high-risk patients transported by nonspecialized teams. Adverse events in pediatric transport tend to be more serious. Airway-related events (loss of endotracheal tube, multiple intubation attempts, malposition of endotracheal tube) are by far the most common adverse event in pediatric transport, followed by loss of critical intravenous (IV) access, sustained hypotension, and cardiac arrest.4–6

image Rapid Transfer, Goal-Directed Therapy, and the Golden Hour

Emergency medical services (EMS) and regional flight teams tend to work under the assumption that the time between the moment of injury and arrival at a center capable of delivering definitive care is among the most important determinants of survival. This notion has been taught for 3 decades but is based on little or no evidence and has recently been scrutinized. Time from scene departure to arrival at the hospital was not associated with survival in out-of-hospital cardiac arrest, and transport time including scene time was not associated with survival in trauma.7,8 At the time the “golden hour” was conceived, prehospital care consisted of providing supplemental oxygen, a fast-moving vehicle, and minimal resuscitation. Under these circumstances, a worse outcome could be expected as prehospital time increased.

Belief in the golden hour may lead to risky behavior. High speeds occasionally result in crashes with injury to EMS providers as well as patients, and EMS have an occupational risk of death similar to that of policemen or firefighters.

There are certainly disease processes—aneurysms requiring neurosurgical intervention, thrombotic events requiring directed thrombolysis, complete transposition of the great arteries requiring urgent atrial septostomy, for example—in which rapid transport to a center that can provide definitive care is the most pressing issue. These are rare in children and, although reasons for interfacility transport of adult patients have not been studied, are likely to represent a small fraction of all critical care adult transports.

In pediatric patients, respiratory failure and shock are the most common reasons for transport. A recent study identified shock in 37% of children transferred to tertiary centers, regardless of reason for referral.9 In adults and children, protocolized, aggressive, early therapy of septic shock has proven vastly more effective than any pharmacologic intervention at improving mortality.10–12

Pediatric protocols recommend aggressive fluid resuscitation, initiation of inotropes, and administration of antibiotics within the first hour after presentation.13 The recommended treatments are simple interventions that can be initiated in community emergency departments (EDs) and continued and refined in transport, provided the treating physician and transferring team appreciate the urgent need and are sensitive to the subtle signs of shock in children. Han et al. reported that when community physicians aggressively resuscitated and successfully reversed shock before a transport team arrived, patients had a ninefold increase in their odds of survival.11 These studies defy the popular notion that out-of-hospital stabilization wastes time and delays definitive therapy that should be rendered at the receiving facility.

Although adult guidelines are more relaxed, there are no data to suggest that it is safe to delay goal-directed therapy for transport. In fact, in adults with septic shock, a delay in antibiotic therapy is associated with worse survival, with mortality increasing by 7% for every 30 minutes that passes without delivery of appropriate antibiotic therapy. The golden hour in transport is the time from presentation to initiation of appropriate treatment, treatments that should be initiated at the referring facility and continued and refined by the transport team.14

image Regionalization of Critical Care

Significant advances in therapeutic and diagnostic interventions for critically ill patients have occurred, but often at great cost and limited availability, prompting the need for transport of these patients to tertiary care centers. A recent consensus conference on prioritizing the organization and management of intensive care services in the United States (PrOMIS) suggested that intensive care would be optimally delivered in a tiered regionalized system.15 Ideally, regionalization would reduce practice variation, improve adherence to best practices, and reduce costs by realizing economies of scale. Regionalization would necessarily result in an increased number of transfers of critically ill patients from lower-volume to higher-volume centers, so the PrOMIS conference proposed that regionalization must be coupled with a regionalized emergency transportation system.

Emergent interfacility transport should occur after initial stabilization and determination by the referring facility that the patient’s needs for care are beyond the scope of local capabilities. In trauma, neonatal intensive care, and pediatric intensive care, the accepting physician serves as an expert who can guide pretransfer stabilization and ensure the safety of transport. Over time, local or low-volume hospitals will have less and less experience with critically ill patients. The transport system may be a useful avenue for education of referring physicians. Receiving centers should have communication centers that facilitate transfers, outreach teams to provide referring facilities with continuing education, and education programs about regional resources and trauma systems.

image Out-of-Hospital Transport

Prehospital Transport

EMS are focused on rapid assessment, stabilization, and transport from the scene to the nearest ED or trauma center that can render appropriate care. Patient management is usually limited to supporting the airway, breathing, and circulation. The transport team should also be able to perform a needle thoracostomy if indicated, control active bleeding, and establish venous access. Other procedures should be kept to a minimum.

Out-of-hospital tracheal intubation by paramedics has recently come under fire. Despite the fact that tracheal intubation is the standard of airway management in the hospital and that tracheal intubation has been practiced by paramedics for 25 years, few studies support a survival benefit of tracheal intubation over bag-valve mask ventilation in the prehospital setting. Tracheal intubation is a complex skill rarely performed by paramedics. Failure rates are high, and multiple attempts are common; both of these may be accompanied by hypoxemia and other physiologic deterioration.16 When intubation is successful, tracheal tube dislodgement during transport by EMS is common; tracheal tube misplacement or dislodgement rate at the time of arrival to ED varies from 5.8% to 12% for adults to 25% for pediatrics.16–18 Finally, uncontrolled hyperventilation during manual ventilation by the EMS crew may be deleterious in head-injured patients and during cardiopulmonary resuscitation (CPR).

Appropriate utilization of resources (air versus ground units) for the prehospital transport of injured patients has been a subject of study and debate since the inception of air medical transport. In general, air medical transport is associated with both shorter transport intervals and a greater medical capability of the transporting team. The decision to use air transport in the prehospital setting should be supported by on-line medical control or preapproved protocols based on the factors of time, distance, geography, patient stability, and local resources. The National Association of Emergency Medical Service Physicians (NAEMSP) and the American College of Emergency Physicians (ACEP) have each recommended triage guidelines for on-scene helicopter transport.19 Retrospective studies have shown improved outcomes in patients transported by air, particularly major trauma patients and patients with severe traumatic brain injury.20–24 Defining the types of specific injuries or medical conditions that benefit from air medical transport has been difficult. As specialized cardiac and stroke centers have developed, air transport has begun to be utilized for rapid transport of these patients directly from the scene.

Interfacility Transport

Most interfacility transfers do not involve critically ill patients and can be accomplished safely a local EMS under predefined protocols or with specific instructions from a command physician. In rural areas, use of local EMS for interfacility transfer risks depleting a large geographic area of valuable medical resources such as ambulances, emergency medical technicians, and paramedics. The referring physician, who has little control over the en route phase of the transport, assumes a significant legal risk. Because of the variable backgrounds of EMS staff, the transferring personnel may not be equipped or trained to provide the necessary care in every situation. In particular, most EMS providers have little experience with critical care beyond the immediate resuscitative measures commonly performed in the prehospital setting, and they may not be trained in the use of certain hospital equipment (e.g., drug infusion pumps.)

In some situations, referring hospital staff may accompany a local ambulance service. The legal risk is reduced because the referring physician maintains tighter control over the patient’s treatment during the transfer. Disadvantages of this option include loss of personnel from the referring hospital and lack of appropriate portable monitoring equipment.

Patients may also be transferred by a regional retrieval system, most of which are centered around air medical transport. Because air medical transport systems are used to transfer sicker patients and are held to a higher standard, the medical teams on these flights offer significantly greater medical capability compared with ground ambulance EMS.

In many instances, regional retrieval teams can also provide ground transport using personnel whose training and experience are held to the higher standard of air medical transport. Air medical transport team members are usually specially trained to deal with out-of-hospital emergencies and are acclimated to the stress of working in a moving environment. The team routinely carries equipment to manage deterioration during transfer and has battery-powered portable monitoring devices designed for use in moving environments. A command physician who is usually based at the institution from which the team originates provides recommendations for management until the team arrives.

Specialty teams provide an even higher level of expertise in the care of selected patients, the largest group being pediatric and neonatal critical care teams. Transport teams with specific expertise in left-ventricular assist devices or extracorporeal membrane oxygenation also exist. In many areas, however, specialty teams are unavailable. Because these teams tend to be based at tertiary care centers, time between decision to transfer and team arrival at the bedside may be longer than for local EMS or a regional air medical team. Specialty teams often perform additional stabilization maneuvers before leaving the referring facility. This practice has been criticized as prolonging bedside time and thus overall transport time interval. In reality, the time to definitive care may be shortened in many critically ill patients transferred by specialty teams. With these teams, the intensive care unit (ICU) is brought to the patient.

In most areas at the time of this writing, regional critical care teams are synonymous with air medical transport teams. However, the U.S. military has developed critical care transport teams with significantly greater capabilities that may serve as a model for critical care specialty civilian teams. In the mid 1990s, the U.S. Air Force began to develop what has come to be called the critical care aeromedical transport team (CCATT.) The team consists of a nurse, respiratory therapist, and physician, all with experience in critical care as well as specific training pertinent to functioning in the transport environment. The teams carry resources to create a mobile ICU, including ventilators, mobile ultrasound equipment, and point-of-care laboratory testing. They go far beyond resuscitation and are able to recognize and manage multiple organ failures. The composition of these teams and details on the equipment and pharmacology they carry are described in an excellent article by Grissom and Farmer.25 In the military, these resource-intensive teams are routinely used to manage up to three critically ill patients in a single transport. Although this model cannot be precisely duplicated in the civilian world, the experience of these teams must be considered when transport systems are designed to support regionalization of critical care.

Issues Specific to Air Medical Transport

Most air medical transport today is done with twin-engine helicopters specially configured for medical missions. The practical transport range for helicopter transfers is generally 150 miles from the craft’s base of operations. For longer-distance transports or in poor weather conditions, fixed-wing aircraft are used by many air medical services. Some flight programs are able use rotorcraft in instrument-flight-rules missions, allowing transport of patients in weather conditions that would otherwise preclude helicopter transport. This method requires filing of a flight plan, which may introduce delay.

The helicopter environment is noisy, so auscultation of blood pressure and breath sounds in flight is difficult if not impossible.26 To monitor patients in flight, transport teams must rely on methods that do not depend on audible sounds: noninvasive blood pressure monitoring, capnometry, and pulse oximetry, to name a few.

Rotorcraft produce significant vibrations, making simple procedures difficult. Most therapeutic interventions such as tracheal intubation, chest decompression, IV access, and control of bleeding must be done before liftoff. The threshold for intubation in pediatric patients undergoing helicopter transport should be slightly lower than in those undergoing ground transport. Intravenous analgesia, sedation, neuromuscular blockade, vasoactive drugs, and blood products can be given in flight. These interventions must be performed under strict on-line medical direction or preapproved protocols.

Barometric pressure changes associated with increasing cabin altitude lower alveolar oxygen tension, increase the volume of any entrapped gas (e.g., in the bowel, sinuses, pneumothorax, endotracheal tube cuffs), and may affect IV infusion rates.

Rotorcraft rarely fly at altitudes more than 2000 feet above ground level. At these altitudes, pressure changes have only a minor impact on the volume of air-filled spaces. The relatively small volume of air in the tracheal tube cuff may be subject to clinically significant pressure changes at that altitude. A recent prospective study found that 98% of patients had tracheal tube cuff pressures above 30 mm Hg, and 72% had intracuff pressures above 50 mm Hg during helicopter transport at a mean of 2260 feet.27 Tracheal tube cuff pressures should be measured and adjusted during flight.

Ventilators are calibrated for performance at sea level. Most flights maintain a cabin pressure equivalent to 6000 to 8000 feet. In the United States, Federal Aviation Administration regulations mandate cabin altitude less than 8000 feet. Ventilators that recognize and compensate for changes in barometric pressure exist (Uni-Vent Eagle Model 754 [Impact Instrumentation Inc., West Caldwell, New Jersey]) but are not in common use outside the military. Tidal volumes delivered by the LTV 1000 (Pulmonetic Systems Inc., Minneapolis, Minnesota), a commonly used transport ventilator, may vary from 5% to 12% at a simulated altitude of 4000 and 8000 in volume control mode. At 15,000 feet, LTV-delivered tidal volumes may be 30% to 37% greater than set tidal volumes.28 Similar findings have been reported with the Drager Oxylog ventilators (Dragger, Telford, Pennsylvania). Ventilators that use pneumatic circuits for respiratory rate control may deliver lower rates and increased tidal volumes at high altitude.29

image Structure of Regional and Specialty Retrieval Systems

The regional retrieval system provides the referral community with transport to locations of tertiary care, providing intensive care when necessary to the patient at both the referring institution and en route. Regional retrieval systems may be independent or may originate at a tertiary care center and should include a communications center, administrative staff, appropriately trained team members, reliable equipment, and a safety program.

Communications

The communications center for the retrieval system should be easily accessible to both the referring physician and the transport team.8,30 It should be staffed around the clock by full-time communication specialists who have no distracting duties. The communication specialist should notify the appropriate personnel and arrange all aspects of the transport so the referring physician can direct his or her attention to patient care. A detailed log of transport requests including time, demographic data, diagnosis, and vehicle availability is kept both for administrative review and medicolegal documentation. Equipment for direct communication with the center should be available in every transport vehicle.

When a request for transfer is initiated, the receiving physician should obtain a brief history of the patient’s present illness, a summary of interventions, and may give the referring physician management recommendations tailored to the capabilities of the referring hospital. Recommendations should be documented on a log that remains a part of the patient’s medical record.

Staffing a Retrieval System

The administrative staff of a retrieval system should include, at a minimum, a program director, medical director, transport coordinator, and medical command.31,32 The program director is responsible for the structure, activities, and organization of the transport system and assumes overall program responsibilities; acts as a liaison between the team and hospital administration; and develops and implements quality management.

The medical director should be a licensed physician specialist in critical care or emergency medicine and might also have training in a surgical subspecialty (trauma) or in pediatrics (neonatology). The medical director should be experienced in both air and ground transport (as appropriate), understand patient care capabilities, and be familiar with limitations and stressors of the transport environment. The medical director must be actively involved in quality management, administrative decisions affecting medical care, and the hiring, training, and continuing education of all transport personnel, including physicians who provide on-line medical direction in policies, procedures, and patient care protocols. The transport medical director may also act as a liaison to the referral community for teaching and outreach.9,30

The transport coordinator, usually a nurse or paramedic, collaborates with the medical director in training, protocols, scheduling, data collection, quality management, and marketing. Whenever possible, the medical director and transport coordinator should participate in patient transport so as to maintain skill and perspective.

A command physician should oversee every transport and provide advice to the referring physician and on-line medical control to the transport team as necessary. The command physician must be experienced in handling transport calls and offering management suggestions for the period before the arrival of the transport team. He or she should be knowledgeable about the availability of resources, have authority to accept transferred patients without further consultation, and perform triage as well as activate backup systems when necessary.

Medical control may be on-line or off-line or a combination of both. On-line medical control is direct real-time voice communication between the medical command physician and the transport team. Medical control physicians must be experienced in critical care transports to ensure that crews provide appropriate care. For specialized transports, the transport service should have a mechanism in place that affords medical control physicians timely consultation with subspecialists or the receiving physician. Alternatively, the critical care transport team should have the ability to consult with the receiving physician and provide updates to the receiving facility. Off-line medical control refers to written protocols or standing orders that guide patient management by the transport team. In some cases, direct communication between the team and the medical control physician is not possible. The medical director is responsible for developing transport protocols and procedures used for off-line medical control.

Transport crewmembers should be experienced in the care of critically ill patients and able to deal with complex environments with limited resources. They must be highly skilled in airway management, resuscitation, and vascular access. They should have a fundamental knowledge of field priorities and be able to make decisions independently. All team members should have specific training in transport medicine, which includes methods of functioning in a moving environment, aeromedical physiology, and troubleshooting for equipment-related problems.

Medical crew composition varies between regional retrieval teams. More than 70% of medical flight crews consist of a nurse-paramedic team. Approximately 20% of programs use two nurses, and only 3% of programs routinely use a flight physician. Respiratory therapists are teamed with nurses in a small percentage of programs and may be particularly appropriate in critical care transport teams.31 Flight nurses typically have extensive experience in the ED or ICU.

Specialty training in critical care is available to paramedics, and board certification for this subspecialty exists. It is unclear what roles critical care paramedics are filling in regional retrieval systems.

Flight physicians are usually emergency medicine residents. In a few programs, they may be attending physicians or medical directors of flight programs. The use of physicians in these services as flight crew members is indicated when the physician might contribute significantly to the care provided in flight. Studies suggest that specific physician judgment or skill may be required in approximately 25% of transports.20,33,34

Equipment

The transport team should be self-sufficient in terms of equipment and medications, should not be dependent on the referring hospital for supplies, and should be prepared to encounter delays or equipment malfunction. The team should carry at least twice the amount of oxygen needed for the expected duration of the trip. Portable compartmentalized equipment packs should be designed for easy access and must be able to withstand the stress of the transport environment. For air medical transport, weight and space restrictions must also be considered in selecting equipment and range of medications. Transport monitors should be free of movement artifact and should have battery power that will last beyond the expected duration of transport. All equipment should be routinely checked and maintained after transport by a team member dedicated to that task.

Safety

Safety should be a high priority in any transport program. Emergency vehicle operation carries substantial risks, not only to the crew and the patient but also to others in its vicinity. Vendors of air or ground transport services should be chosen with attention to safety records, experience of drivers and pilots, and reliability of equipment. Written contracts between the institution and the vendor should include specific insurance details. Ambulance drivers should be discouraged from exceeding the speed limit, because this is unlikely to have a positive effect on patient outcome.

Aeromedical transport involves a unique set of safety issues. A series of high-profile crashes of medical helicopters prompted a review of safety standards for the industry. The four leading causes of accidents are weather, engine failure, collision, and loss of control. Pressure on pilots to fly and failure to observe minimal weather standards are among the components contributing to these accidents. For pilots to make sound decisions based on the flight conditions, they must be isolated from patient care issues. In regions where there are competing aeromedical services, they should act jointly to establish regional safety guidelines, minimal weather standards, and a quality assurance program that would examine compliance.

Transport team members must have a good understanding of aviation medicine and of how the aeromedical environment affects both the team and the patient. The results of poor eating habits (hypoglycemia), sleep deprivation, and drugs (e.g., alcohol, marijuana, antihistamines) are potentiated by increasing altitude. Vibration can produce fatigue, and accelerating and decelerating forces can produce vertigo. Night vision is decreased above cabin altitudes of 5000 feet. The transport team should be adept at survival techniques for their region and should always be prepared to deal with an off-airport landing. Regular sessions to review safety and emergency procedures for each transport mode should be provided for the transport team members.

image Responsibilities of the Referring Hospital

In the United States, the transfer of patients from one institution to another is regulated by federal statute. The Consolidated Omnibus Budget Reconciliation Act of 1986 (COBRA) and its amendment, the Omnibus Reconciliation Act of 1989, set the current legal standard for patient stabilization and transfer.35,36 In an attempt to guarantee equal access to emergency treatment regardless of a patient’s ability to pay, COBRA attributes responsibility for the patient’s transfer to the referring hospital and physician. Violations can result in a number of penalties, including termination of Medicare privileges for the physician and hospital. The Emergency Medical Treatment and Labor Act established by the COBRA legislation governs how patients may be transferred from one hospital to another. Hospitals cannot transfer patients unless the transfer is “appropriate,” the patient consents to transfer after being informed of the risks of transfer, and the referring physician certifies that the medical benefits expected from the transfer outweigh the risks. Appropriate transfers meet the following criteria: (1) the transferring hospital must provide care and stabilization within its ability, (2) copies of medical records and imaging studies must accompany the patient, (3) the receiving facility must have available space and qualified personnel and agree to accept the transfer, and (4) the interfacility transport must be made by qualified personnel with the necessary equipment. It is the responsibility of the referring physician, in consultation with the receiving physician, to choose a mode of transport from among the available teams.

image Unique Aspects of Pediatric Transport

EMS Cannot Provide Ideal Care for All Children

The majority of children are transported by EMS providers with variable educational backgrounds and experience. Currently there are no national regulations for EMS as they relate to children. Pediatric guidelines for EMS are just beginning to evolve from the various national organizations that represent children.37

Limited pediatric training coupled with limited exposure to pediatric patients may hamper the ability of EMS providers to respond appropriately to pediatric emergencies. In 2000, nationally registered paramedics received a median 358 total hours of instruction, less than 5% of which was dedicated to pediatrics. Most paramedics in this study were not required to take pediatric continuing medical education (CME) training.18 Less than 10% of all EMS transports nationwide are for infants and children; 12% of those involve advanced life support, and even fewer provide critical care.38,39 Overall, this translates into 3 pediatric patients per month for 60% of the nation’s paramedics. Although pediatric advanced life support training has been associated with an improvement in ability to secure a pediatric airway or to obtain vascular or intraosseous access, this training is not required for EMS technicians.40

Babl and associates demonstrated that in a program with 50 active ALS providers in the current milieu of EMS, each provider would be expected to have one pediatric bag-valve-mask case every 1.7 years, one pediatric intubation every 3.3 years, and one intraosseous cannulation every 6.7 years.41 Without repeated reinforcement, cognitive and interventional skills deteriorate over time. The poor performance of paramedics in advanced airway management in children is well documented and has led to recommendations that EMS crews avoid tracheal intubation in favor of bag-valve mask ventilation.42

Gausche et al. found that children in the field who were younger than 14 years were more likely to be undertreated compared to adults (33% versus 3%).43 Studies of pediatric trauma victims make it clear that prehospital providers could do a better job with children. Children were twice as likely to die of trauma in the field compared with adults, a finding attributed to the lack of pediatric training.38,42,44

Finally, referring hospitals are often not equipped to care for critically ill and injured children. Two independent studies reported that as recently as 2003, only 6% of emergency rooms were appropriately equipped to care for children. Items frequently unavailable included laryngeal mask airways and infant and neonatal equipment.44 Esposito and coworkers found that frequent errors occur in ED management of pediatric trauma, leading to about 9% preventable mortality.45 They reported a 64% error rate in management of children, including gross violations of basic trauma care. Han et al. found that resuscitation practice in a community ED was consistent with American College of Critical Care Medicine Pediatric Advanced Life Support (ACCM-PALS) guidelines in only 30% of children who presented with septic shock.11

Specialized Teams Improve Outcome

Early investigations of the use of specialized teams for interfacility transport of neonates and children found improved hemodynamic stability and fewer preventable insults with the use of specialized teams.46–49 In a case-control study of preventable insults in head-injured children, Macnab et al. determined that the increase in adverse events with transport by nonspecialty teams resulted in $135,952 in additional costs of care.49 Most importantly, two recent studies have documented an improvement in risk-adjusted mortality with the use of specialized teams for interhospital transfer of pediatric patients.50,51

Pediatric specialized teams bring ICU care to the patient and often perform additional stabilization maneuvers, including upon arrival at the referring facility. In a prospective observational study, pediatric teams initiated sedation 23% of the time, inotropes 44% of the time, and osmolar therapies for intracranial hypertension nearly 50% of the time when the referring facility had failed to do so. Retrieval teams also initiated mechanical ventilation, acquired central venous access, and placed or adjusted tracheal tubes52 (Figure 225-1). Time at the bedside for specialized retrieval teams can be relatively long (97 minutes for neonates and 50 minutes for pediatric patients) because of these interventions, but scene time is not associated with mortality.46,53

image

Figure 225-1 Proportion of interventions performed by referring hospitals and intensive care retrieval teams during stabilization of critically ill children.

(Used with permission from Lampariello S, Clement M, Aralihond AP, Lutman D, Montgomery MA, Petros AJ et al. Stabilisation of critically ill children at the district general hospital prior to intensive care retrieval: a snapshot of current practice. Arch Dis Child 2010;95:681-5.)

The improvement in outcome associated with pediatric specialized transport teams likely stems from unappreciated differences between the respiratory mechanics and cardiovascular physiology in adults and children that lead to a need for earlier, more aggressive intervention in children with common pediatric problems.

In particular, high peripheral airway resistance, small alveoli, and a compliant chest wall increases the risk of lower airway obstructive disease and atelectasis, increases the work of breathing, and increases likelihood of respiratory muscle fatigue. Positive-pressure mechanical support may be required early in the disease process, and airway interventions should be planned so as to avoid having to deal with a respiratory crisis while en route.

Delivery of goal-directed therapy may be hampered by the inability of practitioners to recognize shock. Infants and children have a greater capacity to increase systemic vascular resistance in shock states and tend to preserve blood pressure until very late in the evolution of shock.54 Pediatric shock resuscitation protocols developed by a consensus of experts in the field call for symptomatic treatment of shock using clinical signs including age-specific targets for heart rate and blood pressure and relatively subtle indicators of perfusion as therapeutic endpoints.13 Specialized pediatric teams may be more capable of recognizing deviation from age-specific norms and recognizing the subtle signs of compensated shock in children.

image In-Hospital Transport

Despite the primary focus of transport on prehospital and interfacility settings, in-hospital transport of ICU patients occurs more commonly and may also be life threatening. The transport environment causes some physiologic stress, and almost all patients who are transported experience temporary changes in vital signs requiring some intervention. Over the last 2 decades, the risks associated with in-hospital transport have decreased significantly.

Recent Research

Critically ill adults who require transport out of the ICU for interventions or diagnostic procedures have higher admission severity-of-illness scores with the attendant increase in use of critical care resources than those who do not require transport.55 Because of this, it is difficult to assess the clinical impact of physiologic derangements reported in early evaluations of the safety of in-hospital transport. Still, it is clear that unplanned events are common. In a prospective observational study of in-hospital transports of critically ill patients from the ED, 68% of transports were associated with one or more unplanned events, mostly equipment failures. In the same study, serious unplanned events (hypotension, need for intubation, or elevated intracranial pressure) occurred in 5% of transports.56 High level of experience in the accompanying physician was associated with decreased frequency of unplanned events. A similar series of transports of critically ill patients from the ED to the ICU reported changes in cardiorespiratory physiology requiring intervention in 6% of transports.57

General Principles of In-Hospital Transport

Specific guidelines for in-hospital transport have been published by the American Society for Critical Care Medicine. The general principles of in-hospital transport are the same as those for interfacility transport.58 Patients who require transport from the ICU for procedures and diagnostic studies are sicker on the whole than patients requiring interfacility transport. Patients should be stabilized before the trip. Potential causes of deterioration during transport should be included in planning. Particular attention must be paid to maintenance of hypothermia in patients to whom this therapy has been applied, since rapid rewarming can be devastating to the injured brain. The need for additional sedation should be anticipated. Transfer of critically ill patients to another location should be treated as an extension of intensive care. In the sickest patients, mechanical ventilation is superior to hand ventilation. Adequate medical supervision should be provided during the entire in-hospital transport. Some studies have documented a decrease in unplanned events with greater experience level of the accompanying physician.55

Equipment taken on an in-hospital transport should include a portable system that contains everything normally found on a crash cart and an airway compartment complete with suction apparatus, laryngoscopes, tracheal tubes, bag-valve-mask devices, and medication for emergency intubation. An E-sized oxygen cylinder with a high-pressure regulator, flowmeter, and tubing of sufficient length should accompany all transports and be secured safely to the transport stretcher. Monitoring should include the cardiorespiratory system (electrocardiography, impedance pneumography) at the very least, pulse oximetry for patients in whom oxygen delivery is a potential concern, and the addition of capnography for patients who require mechanical ventilation. Intravascular monitoring should also be continued. It is important to use monitors with reliable batteries in the event of power loss or unexpected delays.

image Conclusion

Traditionally, EMS and regional flight teams have been designed for rapid response and are expected to keep time at the scene to a minimum. In the era of goal-directed therapy for septic shock, it is clear that time-sensitive lifesaving interventions for critically ill patients can be relatively simple and should not be delayed until the patient reaches his or her ICU bed. Where pediatric services, particularly pediatric critical care services, have been regionalized, the use of specialized teams that provide stabilizing interventions beyond what is done by the referring facility improves outcome. Pediatric transport priorities may be a model for what to expect as regionalization of adult critical care services leads to an increase in numbers and acuity of critical care transports as well as a decrease in the referring hospital’s experience with critically ill patients. To realize the benefits of regionalization, intensivists must be actively involved in the planning, maintenance, and quality management of a system that provides constant optimal care.

Key Points

1 During transport, patients are subjected to a high-risk moving environment with limited resources and few monitoring capabilities. The risks of interfacility transport are not precisely known. Adverse events that occur during transport have the potential to negatively impact patient outcome.
2 Except for a few exquisitely time-sensitive disease processes that require interventions not possible in the transport environment, speed of transport alone does not correlate with improved outcomes; the “golden hour” is the time from presentation to initiation of appropriate treatment, not arrival at the accepting facility. Definitive treatment from some common disease processes, including septic shock, should begin at the referring institution and continue during transport.
3 Owing to inadequate training and infrequent contact, adult-oriented emergency medical services (EMS) and air ambulance services may not provide ideal care for critically ill children. The use of specialized pediatric critical care teams has been associated with improved mortality.
4 Regionalization of critical care services will increase the numbers of critically ill patients requiring interfacility transfer. In order to realize the proposed benefits of regionalization, high-quality care must be provided during transport.
5 A retrieval system has a responsibility to the referral community to provide accessible tertiary care. The components include a communications center, administrative staff, appropriately trained team members, reliable equipment, and education and safety programs.
6 A hospital should not transfer until (1) the patient has been appropriately stabilized within the capabilities of the transferring hospital, (2) the patient consents to transfer after being informed of the risks of transfer, (3) the referring physician certifies that the medical benefits expected from the transfer outweigh the risks, and (4) the receiving hospital has available space and has accepted the patient. The referring hospital must prepare copies of medical records and imaging studies to accompany the patient, and the transport must be made by qualified personnel.

Annotated References

Grissom TE, Farmer JC. The provision of sophisticated critical care beyond the hospital: lessons from physiology and military experiences that apply to civil disaster medical response. Crit Care Med. 2005;33:S13-S21.

This article discusses existing systems to provide critical care in environments outside the ICU, including the transport environment, team composition, equipment, and medications necessary for provision of critical care en route. Previous reports of similar data focus on the needs of prehospital teams who perform minimal intervention and rely heavily on speed of transport.

Han YY, Carcillo JA, Dragotta MA, et al. Early reversal of pediatric-neonatal septic shock by community physicians is associated with improved outcome. Pediatrics. 2003;12:793-799.

This study demonstrated that when community physicians successfully achieved shock reversal through aggressive resuscitation before a transport team arrived, patients had a ninefold increase in their odds of survival.

Rivers E, Nguyen B, Havstad S, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med. 2001;345:1368-1377.

This landmark article demonstrated that early goal-directed therapy in the treatment of septic shock before arrival in the ICU improved survival. Patients assigned to the early goal-directed therapy group had improved central venous oxygen saturations, lower base deficits, and a lower incidence of multisystem organ dysfunction compared with those who had standard therapy.

Warren J, Fromm REJr, Orr RA, Rotello LC, Horst HM. American College of Critical Care Medicine. Guidelines for the inter- and intrahospital transport of critically ill patients. Crit Care Med. 2004;32:256-262.

This article is an overview of ACCM standards of care for both interfacility and in-hospital transport.

Orr RA, Felmet KA, Han Y, McCloskey KA, Dragotta MA, Bills DM, et al. Pediatric specialized transport teams are associated with improved outcomes. Pediatrics. 2009;124:40-48.

In a prospective cohort study in which allocation of team depended on team availability, not severity of illness, Orr et al. showed that use of a specialized team resulted in fewer unplanned adverse events and lower mortality compared with use of a nonspecialized team. Most importantly, mortality was high in children transported by nonspecialized teams compared with specialized teams (23% versus 9%), a difference that remained significant when controlling for pre-ICU PRISM score.

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