Abstract

ICU TRIAGE UNDER “NORMAL” CONDITIONS

Once patients meet ICU inclusion criteria, the most commonly recommended triage criteria for ICU admission under “normal” circumstances are “medical benefit” or “first come, first served” (5, 6). Patients who are “too well” or “too sick” to achieve a substantial benefit threshold would not be part of the potential pool. The now quite old Society of Critical Care Medicine triage consensus (5) stated that “The foremost consideration in triage decisions is the expected outcome of the patient in terms of survival and function, which turns on the medical status of the patient. In general, patients with good prognoses for recovery have priority over patients with poor prognoses.” In contrast, the American Thoracic Society recommended that “when demand for ICU beds exceeds supply, medically appropriate patients should be admitted on a first-come, first-served basis” (6).

An updated triage consensus statement unanimously found that triage decisions should give priority for patients with greater benefit and not be made on a “first come, first served basis” (7). Interestingly, in an attempt to develop a survival cutoff for triage decisions, only 77% of respondents agreed to a survival cutoff of 0.1% (7). This may be related to intensivists attempting to rescue with an ICU trial even patients with little chance of surviving knowing that they can later discharge the patient or limit treatments (7). Recent statements on ICU triage also recommended that patients be admitted based on their potential for benefit (8–10). Most statements declared that triage criteria should be explicit, fair, disclosed in advance and not be based on race, ethnicity, sex, sexual preference, financial status, or social worth (5–10). Unfortunately, current triage tools using objective prioritization, diagnosis, or parameter models are unable to provide ICU admission and exclusion criteria with demonstrated improved outcomes (8). Although attempts have been made to develop objective, triage scores (11), none are currently being used. Some triage scoring tools have been specifically developed for use in epidemics; however, none have been validated in a crisis setting (12–17).

The question arises as to how should “first come, first served” and “medical benefit” be defined for ICU admission? As only a few patients are admitted to an ICU every day and beds are either available for incoming patients or can be made available by discharging patients, the “first come, first served” criteria can usually be used for one patient after another. Unfortunately, there are occasions where more than one patient is vying for the last ICU bed. How should the “first patient” be defined when determining “first come, first served” criteria? Is it the first patient admitted to the emergency department, the first patient that the triage officer heard about, the patient in the operating room for whom an ICU bed was reserved, or the first patient that the triage physician accepted? In addition, if there is more than one ICU admission candidate how should “medical benefit” be defined? Is it saving the most lives or saving the most life-years with ICU care for potential patients or the incremental medical benefit between ICU care versus ward care in these patients (10)? If the latter, how much larger must the difference in benefit be? The South African consensus guideline recommended a benefit difference of 15–25% (10). Although intensivists prognosticate more accurately than scoring systems (18), uncertainty remains and physicians’ accuracy lacks the consistency and precision patient desire.

TRIAGE DURING A PANDEMIC OR MASS DISASTER WITH OVERWHELMING SHORTAGES

This article deals only with ICU triage. Complete information related to surge capacity, coordination and collaboration, manpower, essential equipment, pharmaceuticals and supplies, protection of patients and staffing, medical procedures, and education for pandemics can be found elsewhere (19). As difficult as triage decisions are during everyday practice, they are even more challenging during pandemics or mass disasters. Pandemics produce countless critically ill patients that overrun healthcare resources (19). In extreme situations, customary interventions and standards of practice may be unachievable leading to avertible deaths (20, 21). Establishing equitable and just strategies for “the greatest good for the greatest number” of patients may demand decreasing ICU therapies to patients who ordinarily would be expected to benefit from them under conditions of adequate resources (20, 21).

Because of these dilemmas several objective, ICU triage protocols, tools, and scores were developed to prioritize limited reserves, reduce additional deaths and help avoid clinical judgments which might be more protracted and less reliable (12–17). Unfortunately, these tools have been shown to have inadequate performance and many patients classified as too sick to require admission survived (14, 16).

ICU triage of patients remains challenging and controversial in pandemics when resources are overwhelmed. Recommendations for ICU triage for appropriate candidates during pandemics have suggested that either “medical benefit” or a “first come, first served” is acceptable (20, 21) or an improved incremental survival rather than a “first come, first served basis” (22). More recently proposals have been for saving the most lives (23) or saving the most life-years (24). The current COVID-19 pandemic has witnessed the use of age as a criteria, primarily because advanced age appears strongly associated with poorer outcomes (4).

INFORMATION FROM THE PRESENT COVID-19 PANDEMIC

China, Italy, Spain, and the Americas have had major severe acute respiratory syndrome coronavirus 2 outbreaks and mortality. Triage data from some ICUs affected by the COVID-19 pandemic are shown in Table ​Table11. ICU beds and daily census increased approximately double from the previous year. It is too early to evaluate mortality which should be relevant at 28 days after admission. Recent reports of moderately high population mortality from COVID-19 in China (61.5%) (25) and high ICU mortality in the United States (67%) (26) are worrisome. It has been suggested that the high mortality maybe related to the large bed expansion without adequate healthcare resources (27). This has implications for expansions that are currently occurring worldwide. Experience from severe acute respiratory syndrome (SARS) showed that rapid and excessive expansion may overwhelm staff leading to excess infections in healthcare workers and compromising care (28). Thus expansion should be matched by safe staffing to guarantee an appropriate quality of care and staff safety which necessarily limits expansion. A consensus group with first-hand experience of outbreak expansion during SARS concluded that safe expansion is realistically limited by availability of acceptably trained staff and limited to a maximum expansion of 50–100% of baseline capacity (29). Hospitals must also balance ICU needs and the potential decreasing benefits of increasing ICU capacity due to excess workload with other hospital needs (20).

TABLE 1.

ICU Utilization and Outcomes in Three Countries During the Coronavirus Disease 2019 Pandemic Surge

Open in a separate window

Compassionate care should be offered to patients with low-level priorities. There are anecdotal reports that they can survive or delay intubation until more resources are available using awake prone position (30) in hospital wards because of the shortage of ventilators or ICU beds (J. Rello, personal communication, 2020).

ICU TRIAGE DURING A PANDEMIC

How should triage decisions be made during the COVID-19 pandemic? It is strongly recommended that institutions develop prospective, objective protocols or algorithms to assist the implementation of their triage decisions to enhance consistency (31) and decrease moral distress among providers (24, 32). First, when demand surges hospitals must increase ICU capacity by 100–200% (20, 33) before triage is instituted. Triage protocols should only be triggered when resources across a broad geographic area are or will be overwhelmed despite efforts to extend them and systems move from contingency to crisis mode (20). As we can predict a wave of incoming patients from an impending peak in COVID-19, it might be prudent to start rationing prior to expending all resources on early cases with low probabilities for survival when it is clear that maximum surge capacity will certainly be exceeded in the near future. If hospitals cannot provide services, they should consider transferring patients to cities where ICU beds are still available (20). Second, the potential ICU patients should be those that meet inclusion and no exclusion criteria. There is no perfect tool. In deciding which tool to use, we chose a tool that was simple, easy to understand and use and most important providing for quick assessments. As different countries and regions have different infrastructures and resources, laws, cultures, and religions, we attempted to offer flexibility in our recommendations along with explanations for the differing opinions so each region or country can choose what is most appropriate for them.

An illustrative example of inclusion and exclusion criteria and an algorithm for ICU triage is found in Figure ​Figure11 and Supplemental Figure 1 (Supplemental Digital Content 1, http://links.lww.com/CCM/F519; legend, Supplemental Digital Content 2, http://links.lww.com/CCM/F520). Admission priority is given to patients from priority 1 to 4 based on their performance scores, ASA score, number of organ failures, and predicted survival. If there are more priority 1 patients than beds, allocation will be based on incremental ICU benefit defined as saving the most life-years (evaluating mortality from both acute and chronic disorders) (24). If there is a tie for ICU candidates, clinicians should use first come, first served (34) which they are accustomed to using and not a random allocation with a lottery (which they are not familiar using, losing valuable time). We recommend that the first-come patient should be defined as the first patient that the triage officer was informed of. The triage algorithm should apply equally to all ICU candidates with and without COVID-19 (35). When the triage protocol commences, all ICU patients must be reevaluated for remaining in the ICU based on these same criteria.

Open in a separate window

Figure 1.

This tool provides an element of objectivity to help enhance consistency. It is not considered, however, a complete substitute for the carefully considered judgment of an experienced intensive care clinician. The presented algorithm is an example and each institution can decide on which performance score, comorbidities, and organ system failures to use based on their experience and what their staff ifs most comfortable using. A triage (prioritization) decision is a complex clinical decision made when ICU beds are limited. A structured decision-making process is important to maximize transparency and improve consistency in decision-making. A clinical estimation of likely benefit (outcomes from ICU admission compared with outcomes expected if the patient remained on the ward/other care area) is necessary so that patients who will benefit most from ICU are given priority. Examples of clinical conditions that the expert group believe would likely result in a failure of a patient to meet sufficient priority for admission is provided (priority 4). This conceptual algorithm outlines a recommended process for making an individual triage decision, based on a likelihood that survival without ICU care would be low (5–10% or less), and if admission criteria as laid out are met, survival would be estimated to be in excess of 50% short- to medium-term survival. The initial exclusion criteria are based on exclusion criteria used under “normal” conditions so that the same patients are eligible during pandemic conditions and given priority based on their likelihood to benefit. Then patients must meet one of the inclusion criteria. Priorities are then based on those to be “considered first” (priority 1 and then priority 2) and “considered last” (priority 3 and then priority 4) with priority ranking from priority 1 to 4. These exclusions should help foster trust in a fairer triage system with less chance of discrimination. Each decision is assisted on the basis of an agreed criterion thresholds for the particular ICU at a specific time and will be dependent on available resources and the number of patients queuing for admission (e.g., stricter thresholds may be required during the peak of the pandemic, and less strict thresholds at the beginning and toward the end). The performance scores, comorbidities, and organ system failure variables chosen for this example are those that are the quickest to assess. Performance scores: The premorbid baseline condition can be assessed using the Eastern Cooperative Oncology Group Performance Score, the Clinical Frailty Score, the Karnofsky Performance Scale, or other functional impairment tool the user is accustomed. Comorbidities can be assessed using the ASA score, number, or severity of comorbidities. Organ system failures can be assessed using the number of organ system failures or Sequential Organ Failure Assessment. Reevaluations for admitted and refused patients should be performed ideally every 24hr. At reassessment of patients at days 10–14 or if significant deterioration or lack of improvement in the patient’s condition occurs decreasing the patient’s predicted survival to below the current priority group receiving critical care, reallocation of ventilator/ICU bed (following review by triage committee) should be considered. Status/post (S/P) cardiac arrest refers to patients with a recent cardiac arrest or one leading to significant anoxic brain damage.

ACKNOWLEDGMENTS

We thank our colleagues who provided coronavirus disease 2019 (COVID-19) data while caring for their many patients. Marcio Borges Sa, MD, and Maria Aranda Perez, MD, ICU, University Hospital Son Llatzer, IDISBA, Palma de Mallorca, Spain; Department of Intensive Care Medicine, Araba University Hospital, Vitoria, Spain; José Vergara Centeno, MD and Cynthia Campozano Burgos, MD, Hospital General Guasmo Sur, Guayaquil, Ecuador; and Jozef Kesecioglu, MD, PhD, University Medical Center, Utrecht, The Netherlands. We offer our heartfelt thanks to healthcare workers around the world for their skill in caring for COVID-19 patients and who also cared for two of the contributors to this article with COVID-19.

Supplementary Material

Footnotes

REFERENCES