Critical care experts tackle disaster preparation, surge capacity, and rationing

May 13, 2008 (CIDRAP News) – Anticipating that a terrorist attack, influenza pandemic, or natural disaster will someday exhaust regional or national critical care systems, an expert task force recently issued a comprehensive series of reports that takes stock of current capabilities and recommends a surge framework that would care for as many patients as possible but would necessarily exclude some.

The series, from the Critical Care Collaborative Initiative's January 2007 Mass Critical Care Summit, appeared recently in a May supplement issue of the journal Chest. The five articles from the 37-member task force of American and Canadian experts include an executive summary and individual papers on current capabilities, a framework to optimize surge capacity, medical resource guidance, and recommendations for allocating scarce critical care resources in a mass critical care setting.

Task force member John Hick, MD, told CIDRAP News that, although initial mainstream media focus was patient exclusion issues surrounding the task force's ventilator triage criteria, the guidelines are so far receiving good support in the medical community.

"It [the series] provides both a systems and facility-based approach to resource-poor situations," he said. "Whether the goals are reasonable or not, we'll have to see," added Hick, medical director of bioterrorism and disaster preparedness and an emergency medicine physician at Hennepin County Medical Center in Minneapolis and coauthor on three of the five articles.

Though the group covered an expansive array of controversial ethics and resource topics related to critical care in a disaster scenario, they had few disagreements on about 90% of the materials, Hick said. Not surprisingly, the critical care inclusion-exclusion generated the most discussion and required a great deal of compromise, he said.  "It's not exactly what we would do as individuals, but it's a good framework nonetheless," Hick said.

Perhaps the biggest sticking point was the group's recommendation for intensive care unit (ICU) expansion, he said, adding that the group settled on 200% because of pandemic concerns, though many advocated 100% ICU expansion as a more achievable goal.

"My only fear is that people will see that as unrealistic and not aim for what they can achieve, and I think we tried to be clear to do at least what you can," Hick said.

Assessing current resources
In an assessment of current US and Canadian capabilities for critical care during a disaster, including equipment and supplies, staff, and space, the task force points to the likelihood of shortages in many areas.

Mechanical ventilators are essential in critical care, and estimates of the number of ventilators in the US range from about 53,000 to 105,000, the report says. The task force estimates that at least 10,000 ventilators are available nationwide at any given time, but logistical problems would hamper their rapid distribution to areas of need during a disaster.

Moreover, all predictions are that the need for ventilators in a major pandemic will far exceed the supply. The US national stockpile has about 4,600 ventilators, the report says.

One consumable medical item that may run short in a disaster is oxygen, the report says. The number of oxygen suppliers and the number of tanker trucks for shipping oxygen are limited.

Concerning personnel, the report says staff shortages have not typically been a problem in past disasters, but absenteeism has been high in some crises that were prolonged or affected employees personally. In addition, critical care physicians in general are poorly prepared for mass-casualty disasters, and there is evidence that other physician groups are not well prepared for bioterrorism or other public health emergencies, according to the task force.

As for space, the report says that a recent study in Ontario showed that occupancy rates for critical care beds approached 90%. To some extent, hospitals can expand critical care to other areas, such as postanesthesia care units, but shortages of equipment and staff are likely to limit that option.

A hospital facing a major surge of critical care patients might consider sending them to another facility, but for a variety of reasons, this is not likely to be a good immediate option in a disaster, the report says. The possibility of bringing in outside help is not very promising either, the task force asserts.

One possible source of help is the National Disaster Medical System, which was set up to deal with disasters causing a large number of casualties that can't be accommodated by military or Veterans Affairs hospitals. But there are "significant concerns that the system is not equipped to respond to an event involving large numbers of critically ill patients, particularly a biological event, such as a pandemic," the report says.

Critical but limited care
In a separate article, the task force seeks to define the limited level of critical care that hospitals could try to provide in a major disaster and suggests what level of surge capacity hospitals should aim for in this regard.

"Provision of essential rather than limitless critical care will be needed to allow many additional community members to have access to key life-sustaining interventions during disasters," the report states. It stresses that hospitals should use limited, essential critical care, or "emergency mass critical care (EMCC)," only in overwhelming events.

The task force says that EMCC should include the following:

  • Mechanical ventilation
  • Intravenous fluid resuscitation
  • Vasopressor administration
  • Antidote or antimicrobial administration for specific diseases
  • Sedation and analgesia
  • Select practices to reduce adverse consequences of critical illness and critical care delivery
  • Optimal therapeutics and interventions, such as renal replacement therapy and nutrition for patients unable to take food by mouth, if warranted by hospital or regional preference

The report states that every hospital with an intensive care unit should plan to provide EMCC and should coordinate with regional hospital planning efforts in doing so.

As for exactly how much EMCC capacity to aim for, the task force says that multiple uncertainties make it impossible to confidently predict critical care needs for particular types of disasters, but the panel offers recommendations anyway: Hospitals with ICUs should prepare to provide EMCC for at least three times the usual number of critically ill patients and to maintain such care for 10 days without "sufficient external assistance." Ten days is reasonable because most disaster victims' critical care needs are not expected to resolve rapidly, the report says.

The panel also offers a progressive list of changes in resource use for coping with shortages. It starts with substitution and runs through adaptation, conservation, reuse, and finally reallocation, the last meaning taking a resource from one patient and giving it to another with a better prognosis or greater need.

Further, the panel asserts, "All communities should develop a graded response plan for events across the spectrum from multiple casualty to catastrophic critical care events. These plans should clearly delineate what levels of modification of critical care practices are appropriate for the different surge requirements."

The report offers a detailed chart of tiered responses to critical care needs, listing criteria for moving from one level of response to the next. The chart suggests moving to EMCC only at tier 6+, meaning after calls for assistance from local, regional, state, interstate, and federal authorities have been exhausted.

"Sustained EMCC is appropriate when calls for assistance are exhausted and resources are not available or will take days to arrive, and yet critically ill patients remain at high risk for bad outcomes unless critical practice is rationally modified," the article states.

Stocking up for the surge
The task force, in another article focusing on surge capacity, shared guidance on the medical equipment, treatment space, and staffing that will be needed to deliver critical care during a major disaster. The task force said most of the Department of Homeland Security's disaster scenarios represent a double-edged sword. Events, such as a terrorist attack or influenza pandemic, have the potential not only to raise the demand for critical care medical supplies, they also can also sever supply lines.

Hospitals typically rely on "just-in-time" inventories to reduce supply, equipment, and storage costs, they note. "Critical care equipment is no exception, so the quantity of additional critically ill patients a hospital can care for without resupply is impressively small," they wrote.

However, the task force acknowledged that expecting hospitals to stockpile mass quantities of critical care supplies for use during rare catastrophic events is "unrealistic and perhaps even reckless." Instead, the group said its streamlined EMCC framework allows for a more restricted resource list for critical care surge capacity that most communities can accommodate.

They include two tables that list recommended treatment supplies, from endotracheal tubing to blood pressure cuffs, along with minimum quantities for 10 treatment spaces over a span of 10 days. To factor in the uncertainties of patient turnover, the task force suggests increasing stock of consumable supplies above what one patient would require for 10 days.

The authors said they focused a large portion of their surge-capacity equipment recommendations on ventilators because there is little guidance in the medical literature and they anticipate that most patients who will require mechanical ventilation in a mass critical care event will have severe airflow obstruction or lung injury. Given that each patient will probably require several days of ventilation, the task force recommends that each should have his or her own ventilator.

The guidance includes suggestions on short-term strategies to boost ventilator capacity, such as repurposing other types of ventilators, such as anesthesia machines, noninvasive devices, and transport devices, and borrowing from other hospitals that aren't having critical care shortages.

"Hospitals should work with their local, regional, and state partners to perform a PPV [positive-pressure ventilation] need analysis for all plausible mass critical care events, such as a severe influenza pandemic," the task force wrote.

In a surge setting, ventilators should be able to operate without high-pressure medical gas, the task force emphasized. In health facilities, patient care areas outside of critical care units don't typically have the equipment to deliver high-pressure medical gas. Also, a disaster—and subsequent supply chain and transportation disruptions—may require critical care providers to use a patchwork of different oxygen sources.

When addressing where critical care patients should be treated, the expert team discouraged communities from using alternate care sites because of logistical hurdles. Instead, they recommended that general medical patients be discharged to homes or other nonacute settings to allow more critical care patients to be treated in hospitals.

The task force suggested several strategies that healthcare groups could use to augment critical care staffing:

  • Physicians willing to serve in intensivist roles could be encouraged to join critical care teams.
  • Critical care nurses could help mentor noncritical care caregivers.
  • Noncritical care nurses and pharmacists could become responsible for medication delivery to all of the critical care patients.
  • Paramedics could help maintain airways of critical care patients.
  • Respiratory therapists who specialize in critical care could oversee groups of their noncritical care colleagues who could quickly ramp up their skills with just-in-time training materials.
  • Pharmacists from regional health systems could help redistribute scarce pharmaceutical resources.

Tough rationing decisions
The last of the task force's five articles has generated most of the news headlines because it offers a roadmap on which patients should be considered when disaster demands and shortages exhaust the medical system so that not all can receive critical care.

"The lack of a plan to address these issues will result in the perception of unjust allocation of resources, or actual injustice may take place," task force members wrote. The shift from individual to population-based care is best achieved before a disaster occurs, they added.

Though previous antiviral rationing guidance in the event of an influenza pandemic has generally placed healthcare providers in top-priority tiers, the task force does not recommend that health workers—or any other population group—receive preferred status.

According to the group's critical care triage recommendations, critical care resources should be reallocated to other patients in instances when a given patient has a high risk of death and little likelihood of long-term survival and is unlikely to benefit from critical care.

Clinicians should consider two factors when weighing if a patient should receive critical care: daily Sequential Organ Failure Assessment (SOFA) scores and the patient's chronic illness severity. Patients' SOFA scores would be evaluated if their risk of hospital mortality is 80% or greater. Life-limiting illnesses that would exclude patients from receiving scarce critical care resources include conditions such as:

  • Severe trauma
  • Severe burns in certain circumstances
  • Cardiac arrest (unwitnessed or witnessed events that don't respond to electrical therapy)
  • Severe baseline cognitive impairment
  • Metastatic malignancy
  • Advanced, irreversible neurological events or neuromuscular disease
  • End-stage organ failure
  • Age above 85 years

The task force recommends that a triage officer—ideally a highly experienced surgeon who has outstanding leadership and communications skills—review all patients' exclusion and inclusion criteria. "He or she is expected to make decisions that benefit the greatest number of patients given potentially limited resources, even though these decisions may not necessarily be best for any individual patient," the task force wrote.

Attending clinicians will inform patients and family members of the triage officer's decisions, and a triage team made up of clinical care nurses, respiratory therapists, and/or pharmacists will update the triage officer and assist with rationing decisions, the authors wrote.

Decisions to reallocate critical care resources among patients will require a high degree of transparency and regular reviews to ensure that established processes are being followed.

Patients who are excluded from critical care should receive palliative care, the task force said. "During challenging times, it is imperative to uphold the ethical commitment to alleviate discomfort without intentionally hastening death; euthanasia is not acceptable," they wrote. "Thus, it is mandatory that mass disaster preparation anticipates palliation for large numbers of individuals."

The group pointed out that the triage process only applies to patients in acute care settings and that rationing should apply to all acute-care patients, even if their condition isn't related to the disaster events.

They identified several areas that would benefit from more research and care protocols. For example, they said illness severity and scoring systems need more refinement, particularly for pediatric patients.

Also, they wrote that more efforts are needed to train healthcare providers about critical care triage and that strategies are needed for communicating rationing concepts to the public and to the families affected by the triage decisions.

Looking ahead
Hick said now that critical care experts have released their assessments, surge capacity recommendations, and resource allocation guidance, the next step is for states to address liability issues that could protect caregivers and health systems when disasters reduce normal levels of care.

"I hope also that staring down the actual triage criteria from a large group will force states and the federal government to confront these issues and the scarcity of healthcare issues," he said.

The task force doesn't have any more meetings scheduled, but Hick said there are signs that the international community is willing to take on critical care triage issues, such as a research push for better predictive tools for triage.

Devereaux A, Christian MD, Dichter JR, et al. Summary of suggestions from the Task Force for Mass Critical Care Summit, January 26-27, 2007. Chest 2008 May;133(5) Suppl:1S-7S [Full text]

Christian MD, Devereaux AV, Dichter JR, et al. Definitive care for the critically ill during a disaster: current capabilities and limitations. Chest 2008 May;133(5) Suppl:8S-17S [Full text]

Rubinson L, Hick JL, Hanfling DG, et al. Definitive care for the critically ill during a disaster: a framework for optimizing critical care surge capacity. Chest 2008 May;133(5) Suppl:18S-31S [Full text]

Rubinson L, Hick JL, Curtis JR, et al. Definitive care for the critically ill during a disaster: medical resources for surge capacity. Chest 2008 May;133(5) Suppl:32S-50S [Full text]

Devereaux AV, Dichter JR, Christian MD, et al. Definitive care for the critically ill during a disaster: a framework for allocation of scarce resources in mass critical care. Chest 2008 May;133(5) Suppl:51S-66S [Full text]

See also:

May 5 American College of Chest Physicians press release

Apr 30, 2007, CIDRAP News story "New York group offers plan for rationing ventilators in a pandemic"

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