ICU patients frequently lack capacity to provide informed consent for clinical research due to multiple factors. These include sedation, coma, ICU-acquired delirium, or underlying illness. However, the presence of one or more of these characteristics does not automatically designate a potential subject as lacking capacity to provide his or her own informed consent, notes a recent paper.1

“Many can communicate but may not be able to talk due to the endotracheal tube,” says Avelino Verceles, MD, MS, associate professor of medicine in the division of pulmonary, critical care, and sleep medicine at University of Maryland School of Medicine in Baltimore.

Researchers who conduct trials on critically ill patients should be aware that intubation and mechanical ventilation may not always preclude a patient from providing informed consent, underscores Verceles.

Clinicians may seek the input of a legally acceptable representative (LAR) when medical decisions need to be made. “Although the LAR is someone who has the patient’s best interests in mind, there is still the possibility that the LAR’s decision may not be consistent with the patient’s wishes,” says Verceles.

Even if the ICU patient does have capacity, “that doesn’t mean you’re out of the woods,” says Parker Crutchfield, PhD, an associate professor of medical ethics, humanities, and law at Western Michigan University Homer Stryker MD School of Medicine in Kalamazoo.

This is because ICU patients are vulnerable to coercion. “It’s not like they can leave the ICU of their own will,” says Crutchfield. Patients may perceive that if they decline to participate in research, their care will suffer.

Coercion remains an ethical concern even if patients lack decision-making capacity, as surrogates may also believe that receiving good care is contingent on agreeing to participate in research.

One way to mitigate this, says Crutchfield: “Make sure the attending physician is not a member of the research team. Try to get rid of any conflicts of interest.”

Both patients and surrogates need to understand they are free to choose not to participate in the research. “The biggest thing is to make them aware that whoever is treating them will treat them in the same way, whether they do the research or not,” says Crutchfield.

Prospective enrollment at a point in time when the ICU patient does have capacity to consent is sometimes used. Input from the community then becomes more important in contrast to retrospective or interventional research.

“Community engagement enhances protections for vulnerable populations,” says Crutchfield. “It makes it easier for participation to be fully informed.” It also can help identify those who do not want to participate in research. “It takes some creative thinking about what aspect of the community you might go to,” says Crutchfield.

Research ethics consultants or clinical ethicists can be of great help. If the patient suffers from a chronic condition, for example, ethicists may suggest the researcher seek input from a particular group. “Think carefully about the population and who might be able to speak for it,” says Crutchfield.


1. Verceles AC, Bhatti W. The ethical concerns of seeking consent from critically ill, mechanically ventilated patients for research — A matter of possessing capacity or surrogate insight. Clin Ethics 2018; 13(3):107-111.


• Avelino Verceles, MD, Associate Professor of Medicine, Division of Pulmonary and Critical Care, University of Maryland School of Medicine, Baltimore. Phone: (410) 328-8141. Email: