Augmentation of hospital critical care capacity after bioterrorist attacks or epidemics: recommendations of the Working Group on Emergency Mass Critical Care

A porcine model for initial surge mechanical ventilator assessment and evaluation of two limited-function ventilators

OBJECTIVES

To adapt an animal model of acute lung injury for use as a standard protocol for a screening initial evaluation of limited function, or "surge," ventilators for use in mass casualty scenarios.

DESIGN

Prospective, experimental animal study.

SETTING

University research laboratory.

SUBJECTS

Twelve adult pigs.

INTERVENTIONS

Twelve spontaneously breathing pigs (six in each group) were subjected to acute lung injury/acute respiratory distress syndrome via pulmonary artery infusion of oleic acid. After development of respiratory failure, animals were mechanically ventilated with a limited-function ventilator (simplified automatic ventilator [SAVe] I or II; Automedx, Germantown, MD) for 1 hr or until the ventilator could not support the animal. The limited-function ventilator was then exchanged for a full-function ventilator (Servo 900C; Siemens-Elema, Solna, Sweden).

MEASUREMENTS AND MAIN RESULTS

Reliable and reproducible levels of acute lung injury/acute respiratory distress syndrome were induced. The SAVe I was unable to adequately oxygenate five animals with Pao2 (52.0±11.1 torr) compared to the Servo (106.0±25.6 torr; p=.002). The SAVe II was able to oxygenate and ventilate all six animals for 1 hr with no difference in Pao2 (141.8±169.3 torr) compared to the Servo (158.3±167.7 torr).

CONCLUSIONS

We describe a novel in vivo model of acute lung injury/acute respiratory distress syndrome that can be used to initially screen limited-function ventilators considered for mass respiratory failure stockpiles and that is intended to be combined with additional studies to definitively assess appropriateness for mass respiratory failure. Specifically, during this study we demonstrate that the SAVe I ventilator is unable to provide sufficient gas exchange, whereas the SAVe II, with several more functions, was able to support the same level of hypoxemic respiratory failure secondary to acute lung injury/acute respiratory distress syndrome for 1 hr.

Resource allocation after a nuclear detonation incident: unaltered standards of ethical decision making

This article provides practical ethical guidance for clinicians making decisions after a nuclear detonation, in advance of the full establishment of a coordinated response. We argue that the utilitarian maxim of the greatest good for the greatest number, interpreted only as "the most lives saved," needs refinement. We take the philosophical position that utilitarian efficiency should be tempered by the principle of fairness in making decisions about providing lifesaving interventions and palliation. The most practical way to achieve these goals is to mirror the ethical precepts of routine clinical practice, in which 3 factors govern resource allocation: order of presentation, patient's medical need, and effectiveness of an intervention. Although these basic ethical standards do not change, priority is given in a crisis to those at highest need in whom interventions are expected to be effective. If available resources will not be effective in meeting the need, then it is unfair to expend them and they should be allocated to another patient with high need and greater expectation for survival if treated. As shortage becomes critical, thresholds for intervention become more stringent. Although the focus of providers will be on the victims of the event, the needs of patients already receiving care before the detonation also must be considered. Those not allocated intervention must still be provided as much appropriate comfort, assistance, relief of symptoms, and explanations as possible, given the available resources. Reassessment of patients' clinical status and priority for intervention also should be conducted with regularity.

Critical care management of major disasters: a practical guide to disaster preparation in the intensive care unit

Recent events and regulatory mandates have underlined the importance of medical planning and preparedness for catastrophic events. The purpose of this review is to provide a brief summary of current commonly identified threats, an overview of mass critical care management, and a discussion of resource allocation to provide the intensive care unit (ICU) director with a practical guide to help prepare and coordinate the activities of the multidisciplinary critical care team in the event of a disaster.

Pandemic influenza: implications for preparation and delivery of critical care services

In a 5-week span during the 1918 influenza A pandemic, more than 2000 patients were admitted to Cook County Hospital in Chicago, with a diagnosis of either influenza or pneumonia; 642 patients, approximately 31% of those admitted, died, with deaths occurring predominantly in patients of age 25 to 30 years. This review summarizes basic information on the biology, epidemiology, control, treatment and prevention of influenza overall, and then addresses the potential impact of pandemic influenza in an intensive care unit setting. Issues that require consideration include workforce staffing and safety, resource management, alternate sites of care surge of patients, altered standards of care, and crisis communication.

Prioritizing "psychological" consequences for disaster preparedness and response: a framework for addressing the emotional, behavioral, and cognitive effects of patient surge in large-scale disasters

While information for the medical aspects of disaster surge is increasingly available, there is little guidance for health care facilities on how to manage the psychological aspects of large-scale disasters that might involve a surge of psychological casualties. In addition, no models are available to guide the development of training curricula to address these needs. This article describes 2 conceptual frameworks to guide hospitals and clinics in managing such consequences. One framework was developed to understand the antecedents of psychological effects or "psychological triggers" (restricted movement, limited resources, limited information, trauma exposure, and perceived personal or family risk) that cause the emotional, behavioral, and cognitive reactions following large-scale disasters. Another framework, adapted from the Donabedian quality of care model, was developed to guide appropriate disaster response by health care facilities in addressing the consequences of reactions to psychological triggers. This framework specifies structural components (internal organizational structure and chain of command, resources and infrastructure, and knowledge and skills) that should be in place before an event to minimize consequences. The framework also specifies process components (coordination with external organizations, risk assessment and monitoring, psychological support, and communication and information sharing) to support evidence-informed interventions.

The benefits of designing a stratification system for New York City pediatric intensive care units for use in regional surge capacity planning and management

Accurate assessment of New York City (NYC) pediatric intensive care unit (PICU) resources and the ability to surge them during a disaster has been recognized as an important citywide emergency preparedness activity. However, while NYC hospitals with PICUs may be expected to surge in a disaster, few of them have detailed surge capacity plans. This will likely make it difficult for them to realize their full surge capacity both on individual and regional levels. If the pediatric resources that each NYC PICU hospital has can be identified prior to a disaster, this information can be used to both determine appropriate surge capacity goals for each PICU hospital and the additional resources needed to reach those goals. City agencies can then focus citywide planning efforts on making these resources available and more easily anticipate what a hospital will need during a disaster. Communication of this hospital information both prior to and during a surge situation will be aided by a stratification system familiar to both city planners and hospitals. The goal of this project was to design a NYC PICU surge stratification system that would aid physicians, hospitals and city agencies in regional surge capacity planning for critical pediatric patients. This goal was demonstrated through two objectives. The first identified major factors to consider when designing a stratification system. The second devised a preliminary system of PICU stratification based on clinical criteria and resources.

Chapter 5. Essential equipment, pharmaceuticals and supplies. Recommendations and standard operating procedures for intensive care unit and hospital preparations for an influenza epidemic or mass disaster

PURPOSE

To provide recommendations and standard operating procedures for intensive care unit and hospital preparations for an influenza pandemic or mass disaster with a specific focus on essential equipment, pharmaceuticals and supplies.

METHODS

Based on a literature review and expert opinion, a Delphi process was used to define the essential topics including essential equipment, pharmaceuticals and supplies.

RESULTS

Key recommendations include: (1) ensure that adequate essential medical equipment, pharmaceuticals and important supplies are available during a disaster; (2) develop a communication and coordination system between health care facilities and local/regional/state/country governmental authorities for the provision of additional support; (3) determine the required resources, order and stockpile adequate resources, and judiciously distribute them; (4) acquire additional mechanical ventilators that are portable, provide adequate gas exchange for a range of clinical conditions, function with low-flow oxygen and without high pressure, and are safe for patients and staff; (5) provide advanced ventilatory support and rescue therapies including high levels of inspired oxygen and positive end-expiratory pressure, volume and pressure control ventilation, inhaled nitric oxide, high-frequency ventilation, prone positioning ventilation and extracorporeal membrane oxygenation; (6) triage scarce resources including equipment, pharmaceuticals and supplies based on those who are likely to benefit most or on a 'first come, first served' basis.

CONCLUSIONS

Judicious planning and adoption of protocols for providing adequate equipment, pharmaceuticals and supplies are necessary to optimize outcomes during a pandemic.

Chapter 2. Surge capacity and infrastructure considerations for mass critical care. Recommendations and standard operating procedures for intensive care unit and hospital preparations for an influenza epidemic or mass disaster

Purpose

To provide recommendations and standard operating procedures for intensive care unit (ICU) and hospital preparations for a mass disaster or influenza epidemic with a specific focus on surge capacity and infrastructure considerations.

Methods

Based on a literature review and expert opinion, a Delphi process was used to define the essential topics including surge capacity and infrastructure considerations.

Results

Key recommendations include: (1) hospitals should increase their ICU beds to the maximal extent by expanding ICU capacity and expanding ICUs into other areas; (2) hospitals should have appropriate beds and monitors for these expansion areas; hospitals should develop contingency plans at the facility and government (local, state, provincial, national) levels to provide additional ventilators; (3) hospitals should develop a phased staffing plan (nursing and physician) for ICUs that provides sufficient patient care supervision during contingency and crisis situations; (4) hospitals should provide expert input to the emergency management personnel at the hospital both during planning for surge capacity as well as during response; (5) hospitals should assure that adequate infrastructure support is present to support critical care activities; (6) hospitals should prioritize locations for expansion by expanding existing ICUs, using postanesthesia care units and emergency departments to capacity, then step-down units, large procedure suites, telemetry units and finally hospital wards.

Conclusions

Judicious planning and adoption of protocols for surge capacity and infrastructure considerations are necessary to optimize outcomes during a pandemic.

Chapter 7. Critical care triage. Recommendations and standard operating procedures for intensive care unit and hospital preparations for an influenza epidemic or mass disaster

PURPOSE

To provide recommendations and standard operating procedures for intensive care unit (ICU) and hospital preparations for an influenza pandemic or mass disaster with a specific focus on critical care triage.

METHODS

Based on a literature review and expert opinion, a Delphi process was used to define the essential topics including critical care triage.

RESULTS

Key recommendations include: (1) establish an Incident Management System with Emergency Executive Control Groups at facility, local, regional/state or national levels to exercise authority and direction over resources; (2) developing fair and equitable policies may require restricting ICU services to patients most likely to benefit; (3) usual treatments and standards of practice may be impossible to deliver; (4) ICU care and treatments may have to be withheld from patients likely to die even with ICU care and withdrawn after a trial in patients who do not improve or deteriorate; (5) triage criteria should be objective, ethical, transparent, applied equitably and be publically disclosed; (6) trigger triage protocols for pandemic influenza only when critical care resources across a broad geographic area are or will be overwhelmed despite all reasonable efforts to extend resources or obtain additional resources; (7) triage of patients for ICU should be based on those who are likely to benefit most or a 'first come, first served' basis; (8) a triage officer should apply inclusion and exclusion criteria to determine patient qualification for ICU admission.

CONCLUSIONS

Judicious planning and adoption of protocols for critical care triage are necessary to optimize outcomes during a pandemic.

Mass critical care: pediatric considerations in extending and rationing care in public health emergencies

This article applies developing concepts of mass critical care (MCC) to children. In public health emergencies (PHEs), MCC would improve population outcomes by providing lifesaving interventions while delaying less urgent care. If needs exceed resources despite MCC, then rationing would allocate interventions to those most likely to survive with care. Gaps between estimated needs and actual hospital resources are worse for children than adults. Clear identification of pediatric hospitals would facilitate distribution of children according to PHE needs, but all hospitals must prepare to treat some children. Keeping children with a family member and identifying unaccompanied children complicate PHE regional triage. Pediatric critical care experts would teach and supervise supplemental providers. Adapting nearly equivalent equipment compensates for shortages, but there is no substitute for age-appropriate resuscitation masks, IV/suction catheters, endotracheal/gastric/chest tubes. Limitations will be encountered using adult ventilators for infants. Temporary manual bag valve ventilation and development of shared ventilators may prolong survival until the arrival of ventilator stockpiles. To ration MCC to children most likely to survive, the Pediatric Index of Mortality 2 score meets the criteria for validated pediatric mortality predictions. Policymakers must define population outcome goals in regard to lives saved versus life-years saved.

Surgical mask placement over N95 filtering facepiece respirators: physiological effects on healthcare workers

BACKGROUND AND OBJECTIVE

Filtering facepiece respirators ('N95 Masks') may be in short supply during large-scale infectious outbreaks. Suggestions have been made to extend their useful life by using a surgical mask as an outer barrier, but the physiological impact of this added barrier upon the wearer has not been studied.

METHODS

A surgical mask was worn over an N95 filtering facepiece respirator by 10 healthcare workers for 1 h at each of two work rates. Heart rate, respiratory rate, tidal volume, minute volume, oxygen saturation, transcutaneous carbon dioxide levels and respirator dead space gases were monitored and compared with controls (N95 filtering facepiece respirator without a surgical mask). Subjective perceptions of exertion and comfort were assessed by numerical rating scales.

RESULTS

There were no significant differences in physiological variables between those who used surgical masks and controls. Surgical masks decreased dead space oxygen concentrations of the filtering facepiece respirators at the lesser work rate (P = 0.03) and for filtering facepiece respirators with an exhalation valve at the higher work rate (P = 0.003). Respirator dead space oxygen and carbon dioxide levels were not harmonious with Occupational Safety and Health Administration workplace ambient atmosphere standards. Exertion and comfort scores were not significantly impacted by the surgical mask.

CONCLUSIONS

Use of a surgical mask as an outer barrier over N95 filtering facepiece respirators does not significantly impact the physiological burden or perceptions of comfort and exertion by the wearer over that experienced without use of a surgical mask.

Recommendations for intensive care unit and hospital preparations for an influenza epidemic or mass disaster: summary report of the European Society of Intensive Care Medicine's Task Force for intensive care unit triage during an influenza epidemic or mass disaster

PURPOSE

To provide recommendations and standard operating procedures for intensive care units and hospital preparedness for an influenza pandemic.

METHODS

Based on a literature review and expert opinion, a Delphi process was used to define the essential topics.

RESULTS

Key recommendations include: Hospitals should increase their ICU beds to the maximal extent by expanding ICU capacity and expanding ICUs into other areas. Hospitals should have appropriate beds and monitors for these expansion areas. Establish a management system with control groups at facility, local, regional and/or national levels to exercise authority over resources. Establish a system of communication, coordination and collaboration between the ICU and key interface departments. A plan to access, coordinate and increase labor resources is required with a central inventory of all clinical and non-clinical staff. Delegate duties not within the usual scope of workers' practice. Ensure that adequate essential medical equipment, pharmaceuticals and supplies are available. Protect patients and staff with infection control practices and supporting occupational health policies. Maintain staff confidence with reassurance plans for legal protection and assistance. Have objective, ethical, transparent triage criteria that are applied equitably and publically disclosed. ICU triage of patients should be based on the likelihood for patients to benefit most or a 'first come, first served' basis. Develop protocols for safe performance of high-risk procedures. Train and educate staff.

CONCLUSIONS

Mortality, although inevitable during a severe influenza outbreak or disaster, can be reduced by adequate preparation.

Organization of a third-level care hospital in Mexico City during the 2009 influenza epidemic

An outbreak caused by the novel swine-origin influenza A (H1N1) virus was identified in Mexico in late March 2009. The objective of this report is to describe the organization of a tertiary care center in Mexico City during the contingency. We describe the education program, the hospital organization and triaging, and unforeseen overwhelming circumstances. Educational plans were directed to follow standard, contact, and droplet precautions and to condition behavior to avoid touching the eyes, nose, or mouth. N95 respirators were distributed only to perform respiratory procedures. By the fifth month into the epidemic, four patients with hospital-acquired influenza, 467 workers with respiratory symptoms suggestive of influenza (16% of our staff), and 96 workers with confirmed novel influenza A (3% of our staff) were identified. During the first 2 months of the epidemic, 44,225 people went through the triages and only 1503 (3.3%) reached the emergency room. By the fifth month into the epidemic, four small institutional influenza outbreaks (<10 workers each) had been identified, two of them in areas with no patient contact. Molecular testing for influenza was used mainly for epidemiological purposes. Even though we had a supply, we had difficulties in meeting the demand of masks, N-95 respirators, and hand sanitizers. Due to absenteeism, the nursing administration experienced difficulties in covering shifts. Preparation is mandatory for facing an influenza epidemic. The correct use of precautions is an economic measure to limit institutional transmission. Adequate triaging is essential to meet unusual attention demands.

Bacterial pneumonias during an influenza pandemic: how will we allocate antibiotics?

We are currently in the midst of the 2009 H1N1 pandemic, and a second wave of flu in the fall and winter could lead to more hospitalizations for pneumonia. Recent pathologic and historic data from the 1918 influenza pandemic confirms that many, if not most, of the deaths in that pandemic were a result of secondary bacterial pneumonias. This means that a second wave of 2009 H1N1 pandemic influenza could result in a widespread shortage of antibiotics, making these medications a scarce resource. Recently, our University of Michigan Health System (UMHS) Scarce Resource Allocation Committee (SRAC) added antibiotics to a list of resources (including ventilators, antivirals, vaccines) that might become scarce during an influenza pandemic. In this article, we summarize the data on bacterial pneumonias during the 1918 influenza pandemic, discuss the possible impact of a pandemic on the University of Michigan Health System, and summarize our committee's guiding principles for allocating antibiotics during a pandemic.

Prospective meta-analysis using individual patient data in intensive care medicine

Meta-analysis is a technique for combining evidence from multiple trials. However, meta-analyses of studies with substantial heterogeneity among patients within trials-common in intensive care-can lead to incorrect conclusions if performed using aggregate data. Use of individual patient data (IPD) can avoid this concern, increase the power of a meta-analysis, and is useful for exploring subgroup effects. Barriers exist to IPD meta-analysis, most of which are overcome if clinical trials are designed to prospectively facilitate the incorporation of their results with other trials. We review the features of prospective IPD meta-analysis and identify those of relevance to intensive care research. We identify three clinical questions, which are the subject of recent or planned randomised controlled trials where IPD MA offers advantages over approaches using aggregate data.

Emergency department surge capacity: recommendations of the Australasian Surge Strategy Working Group

For more than a decade, emergency medicine (EM) organizations have produced guidelines, training, and leadership for disaster management. However, to date there have been limited guidelines for emergency physicians (EPs) needing to provide a rapid response to a surge in demand. The aim of this project was to identify strategies that may guide surge management in the emergency department (ED). A working group of individuals experienced in disaster medicine from the Australasian College for Emergency Medicine Disaster Medicine Subcommittee (the Australasian Surge Strategy Working Group) was established to undertake this work. The Working Group used a modified Delphi technique to examine response actions in surge situations and identified underlying assumptions from disaster epidemiology and clinical practice. The group then characterized surge strategies from their corpus of experience; examined them through available relevant published literature; and collated these within domains of space, staff, supplies, and system operations. These recommendations detail 22 potential actions available to an EP working in the context of surge, along with detailed guidance on surge recognition, triage, patient flow through the ED, and clinical goals and practices. The article also identifies areas that merit future research, including the measurement of surge capacity, constraints to strategy implementation, validation of surge strategies, and measurement of strategy impacts on throughput, cost, and quality of care.

A retrospective cohort pilot study to evaluate a triage tool for use in a pandemic

Introduction

The objective of this pilot study was to assess the usability of the draft Ontario triage protocol, to estimate its potential impact on patient outcomes, and ability to increase resource availability based on a retrospective cohort of critically ill patients cared for during a non-pandemic period.

Methods

Triage officers applied the protocol prospectively to 2 retrospective cohorts of patients admitted to 2 academic medical/surgical ICUs during an 8 week period of peak occupancy. Each patient was assigned a treatment priority (red -- 'highest', yellow -- 'intermediate', green -- 'discharge to ward', or blue/black -- 'expectant') by the triage officers at 3 separate time points (at the time of admission to the ICU, 48, and 120 hours post admission).

Results

Overall, triage officers were either confident or very confident in 68.4% of their scores; arbitration was required in 54.9% of cases. Application of the triage protocol would potentially decrease the number of required ventilator days by 49.3% (568 days) and decrease the total ICU days by 52.6% (895 days). On the triage protocol at ICU admission the survival rate in the red (93.7%) and yellow (62.5%) categories were significantly higher then that of the blue category (24.6%) with associated P values of < 0.0001 and 0.0003 respectively. Further, the survival rate of the red group was significantly higher than the overall survival rate of 70.9% observed in the cohort (P < 0.0001). At 48 and 120 hours, survival rates in the blue group increased but remained lower then the red or yellow groups.

Conclusions

Refinement of the triage protocol and implementation is required prior to future study, including improved training of triage officers, and protocol modification to minimize the exclusion from critical care of patients who may in fact benefit. However, our results suggest that the triage protocol can help to direct resources to patients who are most likely to benefit, and help to decrease the demands on critical care resources, thereby making available more resources to treat other critically ill patients.

Developing consensus on appropriate standards of disaster care for children

BACKGROUND

Neither professional consensus nor evidence exists to guide the choice of essential hospital disaster interventions. The objective of our study was to demonstrate a method for developing consensus on hospital disaster interventions that should be regarded as essential, quantitatively balancing needs and resources.

METHODS

A panel of pediatric acute care practitioners developed consensus using a modified Delphi process. Interventions were chosen such that workload per staff member would not exceed the previously validated maximum according to the Therapeutic Intervention Scoring System. Based on published models, it was assumed that the usual numbers of staff would care for a disaster surge of 4 times the usual number of intensive care and non-intensive care hospital patients.

RESULTS

Using a single set of assumptions on constrained resources and overwhelming needs, the panel ranked and agreed on essential interventions. A number of standard interventions would exceed crisis workload constraints, including detailed recording of vital signs and fluid balance, administration of vasoactive agents, invasive monitoring of pressures (central venous, intraarterial, intracranial), dialysis, and tube feedings.

CONCLUSIONS

The quantitative methodology and consensus development process described in the present report may have utility in future planning. Groups with appropriate expertise must develop action plans according to authority within each jurisdiction, addressing likely disaster scenarios, according to the needs in each medical service region, using available regional resources, and accounting for the capabilities of each institution.

Evaluation of the filtration performance of 21 N95 filtering face piece respirators after prolonged storage

Background

Organizations are stockpiling respirators to prepare for an influenza pandemic. To understand better the effects of prolonged storage, this investigation evaluated the filtration efficiency of 21 different models of National Institute for Occupational Safety and Health (NIOSH)-certified disposable N95 filtering face piece respirators. These respirators had been stored in their original packaging for a period of at least 6 years in research laboratories and dry warehouse facilities, ranging in temperature between 15°C and 32°C and relative humidity between 20% and 80%.

Methods

Filter penetration was measured using an abbreviated version of the NIOSH respirator certification test incorporating a polydisperse sodium chloride aerosol at 85 L/min.

Results

Of the 21 respirator models tested, 19 models had both average penetration results of less than 5%. Mean initial penetration values ranged from 0.39% to 5.83%, whereas mean maximum penetration values ranged from 0.95% to 5.83%. There did not appear to be any correlation between the length of storage and failure to pass the filtration test.

Conclusion

Results indicate that most N95 filtering face piece respirators stored for up to 10 years at warehouse conditions will likely have expected levels of filtration performance and that the degree of filtration efficiency degradation is likely model specific.

Pandemic Influenza: Impact on Perianesthesia Nursing Areas

As our readers are aware, these pages are typically used by the editors. However, in light of the recent events and concerns surrounding the swine flu, the editors have elected to quickly substitute an informative piece regarding influenza for the usual editorial. We thank Dr. Daphne Stannard for her willingness to disseminate her knowledge on the topic. The Editors

Who should receive life support during a public health emergency? Using ethical principles to improve allocation decisions

A public health emergency, such as an influenza pandemic, will lead to shortages of mechanical ventilators, critical care beds, and other potentially life-saving treatments. Difficult decisions about who will and will not receive these scarce resources will have to be made. Existing recommendations reflect a narrow utilitarian perspective, in which allocation decisions are based primarily on patients' chances of survival to hospital discharge. Certain patient groups, such as the elderly and those with functional impairment, are denied access to potentially life-saving treatments on the basis of additional allocation criteria. We analyze the ethical principles that could guide allocation and propose an allocation strategy that incorporates and balances multiple morally relevant considerations, including saving the most lives, maximizing the number of "life-years" saved, and prioritizing patients who have had the least chance to live through life's stages. We also argue that these principles are relevant to all patients and therefore should be applied to all patients, rather than selectively to the elderly, those with functional impairment, and those with certain chronic conditions. We discuss strategies to engage the public in setting the priorities that will guide allocation of scarce life-sustaining treatments during a public health emergency.

The Needs of Children in Natural or Manmade Disasters

Disasters have been described as “events of sufficient scale, asset depletion, or numbers of victims to overwhelm medical resources” [1] or as “a serious disruption of the functioning of a community or a society causing widespread human, material, economic or environmental losses that exceed the ability of the affected community or society to cope using its own resources” [2]. Importantly, that definition goes on to state: “A disaster is a function of the risk process. It results from the combination of hazards, conditions of vulnerability and insufficient capacity or measures to reduce the potential negative consequences of risk.”

Definitive care for the critically ill during a disaster: a framework for optimizing critical care surge capacity: from a Task Force for Mass Critical Care summit meeting, January 26-27, 2007, Chicago, IL

BACKGROUND

Plausible disasters may yield hundreds or thousands of critically ill victims. However, most countries, including those with widely available critical care services, lack sufficient specialized staff, medical equipment, and ICU space to provide timely, usual critical care for a large influx of additional patients. Shifting critical care disaster preparedness efforts to augment limited, essential critical care (emergency mass critical care [EMCC]), rather than to marginally increase unrestricted, individual-focused critical care may provide many additional people with access to life-sustaining interventions. In 2007, in response to the increasing concern over a severe influenza pandemic, the Task Force on Mass Critical Care (hereafter called the Task Force) convened to suggest the essential critical care therapeutics and interventions for EMCC.

TASK FORCE SUGGESTIONS

EMCC should include the following: (1) mechanical ventilation, (2) IV fluid resuscitation, (3) vasopressor administration, (4) medication administration for specific disease states (eg, antimicrobials and antidotes), (5) sedation and analgesia, and (6) select practices to reduce adverse consequences of critical illness and critical care delivery. Also, all hospitals with ICUs should prepare to deliver EMCC for a daily critical care census at three times their usual ICU capacity for up to 10 days.

DISCUSSION

By using the Task Force suggestions for EMCC, communities may better prepare to deliver augmented critical care in response to disasters. In light of current mass critical care data limitations, the Task Force suggestions were developed to guide preparedness but are not intended as strict policy mandates. Additional research is required to evaluate EMCC and revise the strategy as warranted.

Organizational characteristics of the austere intensive care unit: the evolution of military trauma and critical care medicine; applications for civilian medical care systems

Critical care in the U.S. military has significantly evolved in the last decade. More recently, the U.S. military has implemented organizational changes, including the use of multidisciplinary teams in austere environments to improve outcomes in severely injured polytrauma combat patients. Specifically, organizational changes in combat support hospitals located in combat zones during Operation Iraqi Freedom have led to decreased intensive care unit mortality and length of stay as well as resource use. These changes were implemented without increases in logistic support or the addition of highly technologic equipment. The mechanism for improvement in mortality is likely attributable to the adherence of basic critical care medicine fundamentals. This intensivist-directed team model provides sophisticated critical care even in the most austere environments. To optimize critically injured patients' outcomes, intensive care organizational models similar to the U.S. military, described in this article, can possibly be adapted to those of civilian care during disaster management to meet the challenges of emergency mass critical care.

Critical care in the austere environment: providing exceptional care in unusual places

BACKGROUND

War and other disasters are inexorably linked to illness and injury. As a consequence of this, healthcare providers will be challenged to provide advanced physiological support to preserve human life. Given the mobility and modularity of modern medical systems, the ability to provide critical care outside of the confines of traditional hospitals under such circumstances has become not only a reality and periodic necessity, but an expectation. Austerity amplifies the complexity of providing high-level critical care, because resources are frequently limited, providers are asked to fill unexpected roles determined by necessity, security may be threatened, and the population at risk and their afflictions can be highly diverse.

DISCUSSION

Our current deployed military medical experience and a review of published literature pertaining to civilian medical disaster response efforts support these stated challenges. The fundamentals of successful critical care practice in unusual settings include proper planning with an emphasis on attention to detail, the careful management of all resources, using the proper equipment, leveraging aeromedical evacuation assets, and employing the right people with the right skills.

SUMMARY

Adherence to sound, evidence-based, routine practice, within bounds of the circumstances, must underscore everything.

Mechanical ventilation in an airborne epidemic

With the increasing threat of pandemic influenza and catastrophic bioterrorism, it is important for intensive care providers to be prepared to meet the challenge of large-scale airborne epidemics causing mass casualty respiratory failure. The severe acute respiratory syndrome outbreak exposed the vulnerability of health care workers and highlighted the importance of establishing stringent infection control and crisis management protocols. Patients who have acute lung injury and acute respiratory distress syndrome who require mechanical ventilation should receive a lung protective, low tidal volume strategy. Controversy remains regarding the use of high-frequency oscillatory ventilation and noninvasive positive pressure ventilation. Standard, contact, and airborne precautions should be instituted in intensive care units, with special care taken when aerosol-generating procedures are performed.

[The organisation of intensive care in a situation of pandemic avian influenza]

The development of an epidemic of avian influenza will have a major impact on the organisation and structure of the facilities for treatment. This paper, the product of collaboration between the six learned societies concerned, analyses the impact of a possible pandemic on the various aspects of management of patients requiring intensive care. It describes the organisation of hospital pathways for flu and non-flu patients with, in particular, the necessary actions in terms of separation of care facilities, the triage of patients and the cancellation of non-urgent activities. It analyses the preconditions necessary for the efficient functioning of intensive care and the predictable limiting factors. It underlines the importance of training of medical and paramedical personnel. Finally, it tackles the specific problems of paediatric intensive care: organisation, capacity for admissions and training.

Mass-casualty incidents: how does an ICU prepare?

Despite the ever-present risk of mass-casualty incidents (MCIs) in all geographical regions, there is a limited body of literature detailing specifically how an intensive care unit (ICU) prepares for such an event. When responding to an overwhelming volume of severely injured victims, the intensivist must make a paradigm shift away from providing complete care to all patients to one of preferentially administering care to those with the greatest likelihood of survival. To do this effectively, ICU directors must possess a detailed understanding of the entire disaster response, including organization, triage, staffing, and treatment. This article provides a comprehensive review of each of these topics, as well as a framework on specific elements of critical care and treatment based on published literature and expert opinion to assist the clinician in directing care to where it is most appropriate.

Definitive care for the critically ill during a disaster: medical resources for surge capacity: from a Task Force for Mass Critical Care summit meeting, January 26-27, 2007, Chicago, IL

BACKGROUND

Mass numbers of critically ill disaster victims will stress the abilities of health-care systems to maintain usual critical care services for all in need. To enhance the number of patients who can receive life-sustaining interventions, the Task Force on Mass Critical Care (hereafter termed the Task Force) has suggested a framework for providing limited, essential critical care, termed emergency mass critical care (EMCC). This article suggests medical equipment, concepts to expand treatment spaces, and staffing models for EMCC.

METHODS

Consensus suggestions for EMCC were derived from published clinical practice guidelines and medical resource utilization data for the everyday critical care conditions that are anticipated to predominate during mass critical care events. When necessary, expert opinion was used. TASK FORCE MAJOR SUGGESTIONS: The Task Force makes the following suggestions: (1) one mechanical ventilator that meets specific characteristics, as well as a set of consumable and durable medical equipment, should be provided for each EMCC patient; (2) EMCC should be provided in hospitals or similarly equipped structures; after ICUs, postanesthesia care units, and emergency departments all reach capacity, hospital locations should be repurposed for EMCC in the following order: (A) step-down units and large procedure suites, (B) telemetry units, and (C) hospital wards; and (3) hospitals can extend the provision of critical care using non-critical care personnel via a deliberate model of delegation to match staff competencies with patient needs.

DISCUSSION

By using the Task Force suggestions for adequate supplies of medical equipment, appropriate treatment space, and trained staff, communities may better prepare to deliver augmented essential critical care in response to disasters.

Definitive care for the critically ill during a disaster: current capabilities and limitations: from a Task Force for Mass Critical Care summit meeting, January 26-27, 2007, Chicago, IL

In the twentieth century, rarely have mass casualty events yielded hundreds or thousands of critically ill patients requiring definitive critical care. However, future catastrophic natural disasters, epidemics or pandemics, nuclear device detonations, or large chemical exposures may change usual disaster epidemiology and require a large critical care response. This article reviews the existing state of emergency preparedness for mass critical illness and presents an analysis of limitations to support the suggestions of the Task Force on Mass Casualty Critical Care, which are presented in subsequent articles. Baseline shortages of specialized resources such as critical care staff, medical supplies, and treatment spaces are likely to limit the number of critically ill victims who can receive life-sustaining interventions. The deficiency in critical care surge capacity is exacerbated by lack of a sufficient framework to integrate critical care within the overall institutional response and coordination of critical care across local institutions and broader geographic areas.

Effect of surgical masks worn concurrently over N95 filtering facepiece respirators: extended service life versus increased user burden

Growing concern over the availability of Respiratory protective devices (eg, filtering facepiece Respirators), in the face of the probable extreme demand brought on by a pandemic influenza, has prompted the suggestion that useful life of N95 filtering facepiece Respirator can be extended by the concurrent use of a surgical mask as an outer protective barrier over the Respirator. Personal protective equipment generally places a strain on the user, and the detrimental physiological and psychological burdens normally imposed by Respirator use could be magnified by the addition of an extra layer of protection such as a surgical mask. The issue of this potentially increased burden of the concurrent use of a surgical facemask with an N95 filtering facepiece Respirator is investigated to afford users the necessary information to make informed decisions Regarding the use of this Respiratory personal protective equipment in the face of large-scale outbreaks of Respiratory pathogens.

Clinical review: allocating ventilators during large-scale disasters--problems, planning, and process

Catastrophic disasters, particularly a pandemic of influenza, may force difficult allocation decisions when demand for mechanical ventilation greatly exceeds available resources. These situations demand integrated incident management responses on the part of the health care facility and community, including resource management, provider liability protection, community education and information, and health care facility decision-making processes designed to allocate resources as justly as possible. If inadequate resources are available despite optimal incident management, a process that is evidence-based and as objective as possible should be used to allocate ventilators. The process and decision tools should be codified pre-event by the local and regional healthcare entities, public health agencies, and the community. A proposed decision tool uses predictive scoring systems, disease-specific prognostic factors, response to current mechanical ventilation, duration of current and expected therapies, and underlying disease states to guide decisions about which patients will receive mechanical ventilation. Although research in the specifics of the decision tools remains nascent, critical care physicians are urged to work with their health care facilities, public health agencies, and communities to ensure that a just and clinically sound systematic approach to these situations is in place prior to their occurrence.

Clinical review: critical care transport and austere critical care

The development of modern intensive care units (ICUs) has allowed the survival of patients with advanced illness and injury, although at a cost of substantial infrastructure. Natural disasters and military operations are two common situations that can create critically ill patients in an environment that is austere or has been rendered austere. This has driven the development of two related strategies to care for these casualties. Portable ICU capability can be rapidly established in the area of need, providing relatively advanced capability but limited capacity and sustainability. The other strategy is to rapidly evacuate critically ill and injured patients following their initial stabilization. This permits medical personnel in the austere location to focus resources on a larger number of less critical patients. It also permits the most vulnerable patients to receive care in an advanced center. This strategy requires careful planning to overcome the constraints of the transport environment. The optimal strategy has not been determined, but a combination of these two approaches has been used in recent disasters and military operations and is promising. The critical care delivered in an austere setting must be integrated with a long-term plan to provide follow-on care.

Biological terrorism

A biological terrorism event could have a large impact on the general population and health care system. The impact of an infectious disaster will most likely be great to emergency departments, and the collaboration between emergency and infectious disease specialists will be critical in developing an effective response. A bioterrorism event is a disaster that requires specific preparations beyond the usual medical disaster planning. An effective response would include attention to infection control issues and plans for large-scale vaccination or antimicrobial prophylaxis. This article addresses some general issues related to preparing an effective response to a biological terrorism event. It will also review organisms and toxins that could be used in biological terrorism, including clinical features, management, diagnostic testing, and infection control.

Clinical review: mass casualty triage--pandemic influenza and critical care

Worst case scenarios for pandemic influenza planning in the US involve over 700,000 patients requiring mechanical ventilation. UK planning predicts a 231% occupancy of current level 3 (intensive care unit) bed capacity. Critical care planners need to recognise that mortality is likely to be high and the risk to healthcare workers significant. Contingency planning should, therefore, be multi-faceted, involving a robust health command structure, the facility to expand critical care provision in terms of space, equipment and staff and cohorting of affected patients in the early stages. It should also be recognised that despite this expansion of critical care, demand will exceed supply and a process for triage needs to be developed that is valid, reproducible, transparent and consistent with distributive justice. We advocate the development and validation of physiological scores for use as a triage tool, coupled with candid public discussion of the process.

Pandemic preparedness

PURPOSE OF REVIEW

Pandemic influenza remains a threat to world health and will probably result in an overwhelming number of critically ill patients. Preparations should be made now to meet this threat.

RECENT FINDINGS

Limited data are available on which to base preparations. Adequate staffing is crucial to the functioning of an ICU and therefore occupational safety is of central concern. In the absence of knowledge of the method of spread of a pandemic disease, it would seem appropriate to take airborne and contact precautions, and the literature related to this area is reviewed. Methods of recruiting and training additional staff and the issues of bed capacity, stockpiling, triage and ethics are discussed.

SUMMARY

Extensive preparation is needed in advance of an epidemic. This should include occupational safety measures, stockpiling of equipment and drugs, staff training, development of triage policies, and discussion of the limits of duty of care to patients. These preparations take considerable time and therefore these issues should be tackled urgently.

Strategies to improve pediatric disaster surge response: potential mortality reduction and tradeoffs

OBJECTIVE

To estimate the potential for disaster mortality reduction with two surge response strategies: 1) control distribution of disaster victims to avoid hospital overcrowding near the scene, and 2) expand capacity by altering standards of care to only "essential" interventions.

DESIGN

Quantitative model of hospital mortality.

SETTING

New York City pediatric intensive care unit and non-intensive care unit pediatric hospital capacity and population.

MEASUREMENTS AND MAIN RESULTS

Mortality was calculated for a hypothetical sudden disaster, of unspecified mechanism, assuming 500 children per million population need hospitalization, including 30% severely ill/injured warranting pediatric intensive care unit care, with high (76%) predisaster hospital occupancy. Triage rules accommodated patients at lower levels of care if capacity was exhausted. Specified higher relative mortality risks were assumed with reduced levels of care. In a pessimistic baseline scenario, hospitals near the disaster scene, considered to have 20% of regional capacity, were overcrowded with 80% of the surge patients. Exhausted capacity at overcrowded hospitals near the scene would account for most of the 45 deaths. Unused capacity would remain at remote facilities. If regional surge distribution were controlled to avoid overcrowding near the scene, then mortality would be reduced by 11%. However, limited pediatric intensive care unit capacity would still require triage of many severe patients to non-intensive care unit care. Instead, if altered standards of care quadrupled pediatric intensive care unit and non-intensive care unit capacity, then mortality would fall 24% below baseline. Strategies 1 and 2 in combination would improve mortality 47% below baseline. If standards of care were altered prematurely, preventable deaths would occur. However, additional simulations varying surge size, patient severity, and predisaster occupancy numbers found that mortality tradeoffs would generally favor altering care for individuals to improve population outcomes within the range of federal planning targets (500 new patients/million population).

CONCLUSION

Quantitative simulations suggest that response strategies controlling patient distribution and expanding capacity by altering standards of care may lower mortality rates in large disasters.

Mass casualty respiratory failure

PURPOSE OF REVIEW

The severe acute respiratory syndrome epidemic of 2002-2003, recent natural catastrophes, burgeoning concerns regarding intentional catastrophes, and the looming threat of an influenza pandemic have focused attention on large-scale, survivable respiratory failure. In this article, we review appropriate medical equipment, treatment space, and strategies to augment health professional staff in response to a massive increase in need for sustained critical care.

RECENT FINDINGS

There is insufficient modern healthcare experience with mass casualty respiratory failure to develop evidence-based preparedness efforts. For this reason, initial efforts to augment critical care capability in response to disasters have relied on extrapolation from the routine critical care knowledge base, military medicine, critical care transport, and expert opinion. We review recently published documents on augmenting supplies of positive pressure ventilation equipment, ongoing projects for increasing health professional staff, and infection control issues during epidemics.

SUMMARY

Mass casualty respiratory failure remains a largely unstudied field, but we believe informed decisions about equipment stockpiling and use, the development of creative operational concepts to increase staffing, and the careful implementation of rational infection control practices can lay a foundation for an appropriate response until additional data become available.