During an epidemic or disaster there may be not enough mechanical ventilators for everyone who needs one. Hick and O'Laughlin listed criteria for prioritizing patients to receive mechanical ventilation when resources are the limiting factor. The authors are from Hennepin County Medical Center, Abbott Northwestern Hospital and the University of Minnesota in Minneapolis.


Patients in the following groups should not be offered mechanical ventilation OR should have mechanical ventilation withdrawn. A hospital may make modifications based on local conditions and patient populations.



(1) respiratory failure requiring intubation with

(1a) persistent hypotension (adult with systolic blood pressure < 90 mm Hg) unresponsive to adequate fluid resuscitation after 6-12 hours

(1b) signs of failure in one or more nonpulmonary organs

(2) severe bacterial pneumonia with failure to respond to (a) mechanical ventilation and (b) appropriate antibiotic therapy after 3 or more days of therapy (depending on pathogen)

(3) multiple (>=4) organ failures based on clinical or laboratory evidence (respiratory, cardiovascular. renal. hepatic. neurologic, hematologic)

(4) presence of respiratory failure requiring intubation with 1 or more of the following:

(4a) congestive heart failure with left ventricular ejection fraction < 25%

(4b) persistent cardiac ischemia unresponsive to therapy with pulmonary edema

(4c) acute renal failure requiring hemodialysis

(4d) severe chronic lung disease requiring continuous oxygen use prior to onset of acute illness

(4e) AIDS or other immunodeficiency syndrome at an advanced stage of the disease when the patient is highly susceptible to opportunistic infection

(4f) active malignancy with poor potential for survival

(4g) cirrhosis with ascites OR history of variceal bleeding OR fixed coagulopathy OR encephalopathy

(4g) acute hepatic failure with hyperammonemia

(4i) irreversible, severe neurologic impairment with patient totally dependent for care

(5) Sequential Organ Failure Assessment (SOFA) score above cutoff score



• An adequate response to mechanical ventilation includes improved oxygenation and lung compliance.

• In the implementation number of extrapulmonary organ failures required is >= 3 since respiratory failure is included in item 3.


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