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Ethics in the intensive care unit: Informed consent

Ethics in the intensive care unit: Informed consent
Douglas B White, MD, MAS
Section Editor:
Polly E Parsons, MD
Deputy Editor:
Geraldine Finlay, MD
Literature review current through: Nov 2022. | This topic last updated: Jul 30, 2021.

INTRODUCTION — Informed consent is a process of communication between a clinician and a patient or surrogate decision-maker that results in the patient/surrogate agreeing (or refusing) to undergo a specific medical intervention. Consent for specific aspects of medical treatment is a relatively new concept in medical ethics, having evolved over the last century. Medical decision-making previously occurred under a model that assumed that clinicians, given their technical medical expertise, could adequately know what was good for their patients without consulting them. This model was criticized because it fails to adequately account for the fact that there is often more than one reasonable treatment option, patients may choose different options depending on their values, and clinicians are generally not well-positioned to know what individual patients most value [1-3]. Moreover, it does not adequately acknowledge the importance of manifesting respect for patients as persons, which in the medical context entails efforts to allow patients to choose what happens to their bodies.

During the mid-1980s, this paternalistic model gave way to a model that placed more value on efforts to respect patient autonomy. Ideally, this was achieved through effective conversations in which patients were given enough information about the available treatment options so that they could choose the one that best matched their values and preferences. However, this ideal of patient engagement was sometimes misinterpreted as a call to let patients choose any therapy they desired, without advice from clinicians, out of a concern that such advice might inappropriately influence the patient and thereby infringe on patient autonomy. An all-too-common scenario in intensive care units (ICUs) in this era was one in which patients or surrogates were confronted with an open-ended request from the medical team such as "What do you want us to do?" without a clear explanation of options and or input from the clinician. Consequently, under-informed patient/surrogates often responded with the understandable request to "do everything," which clinicians mistakenly accepted as autonomous guidance that must be followed even if the clinician thought the patient's choice was mistaken.

It is increasingly recognized that expert advice can enhance rather than impede patients' ability to make autonomous choices that reflect their values and preferences. As a result, norms are shifting toward a truly shared approach to decision making in which both the clinician and the patient/surrogate are active participants in deliberations [4-6].

Ethical issues related to informed consent in the ICU are reviewed here. Our emphasis is on informed consent for medical interventions such as arterial catheterization, central venous catheterization, bronchoscopy, endotracheal intubation, and thoracentesis. Although many principles also apply to informed consent for surgery and participation in clinical research, these areas are beyond the scope of this review. Ethical issues related to withholding life support, withdrawing life support, and requests for futile or inappropriate therapy are discussed separately. (See "Withholding and withdrawing ventilatory support in adults in the intensive care unit" and "Ethics in the intensive care unit: Responding to requests for potentially inappropriate therapies in adults".)

JUSTIFICATION FOR INFORMED CONSENT — The primary ethical justification for obtaining informed consent from patients is to respect their right to determine what happens to their bodies (ie, respect for autonomy). This entails a right to approve or refuse treatments that clinicians judge to be medically reasonable. It is important to note that this is a narrower right than a right to demand any medical intervention, regardless of whether the clinician believes it is medically reasonable.

Strictly speaking, the ethical justification for obtaining informed consent from surrogates of incapacitated patients is not grounded in respect for patient autonomy. This is because one of the requirements of autonomous choice is that patients actually make a choice, which incapacitated patients cannot do. In the absence of an oral or written advanced directive, no prior choice was made by the patient. Hence, there is no actual opportunity to respect patient autonomy. Therefore, clinicians and surrogates analyze patients' prior statements, values, and beliefs and attempt to make a decision that broadly respects the patient as a person, which is a broader construct than respect for patient autonomy. Although the goal is to determine what the patient might choose if they were able to do so, this "substituted judgment" does not actually constitute an autonomous choice by the patient, but rather attempts to make decisions that are "authentic" to the patient [7]. Importantly, evidence suggests that >90 percent of patients prefer family members to work with the clinician to make medical decisions for them if they are incapacitated [8].

EMERGENCY EXCEPTION TO THE REQUIREMENT FOR INFORMED CONSENT — An exception to the requirement for informed consent is recognized when an emergent, lifesaving procedure is required (eg, endotracheal intubation in the setting of acute respiratory failure) and delaying the procedure in order to obtain informed consent would pose a risk of serious, imminent harm (eg, death or severe disability). In such emergencies, the courts have recognized a doctrine of implied consent; the clinician may assume the patient would consent based on the assumption that no reasonable person would refuse the procedure in the circumstances. Examples include administering CPR to someone who collapses on the street with cardiac arrest or establishing central vascular access in the setting of a massive upper gastrointestinal hemorrhage.

The emergency exception should not be used when it is possible to obtain informed consent. Moreover, it should not be used to override a patient's clearly articulated treatment preferences (eg, a patient who refuses blood transfusions on religious grounds). Finally, even if a complete informed consent conversation is not possible, it is often possible in emergency settings to have an abbreviated discussion about the treatment in question.  

PROCESS OF INFORMED CONSENT — Informed consent is a communication process rather than merely obtaining a signed consent document. The process of obtaining informed consent involves five steps:

Ensuring the patient or surrogate has decision-making capacity (see 'Assess decision-making capacity' below)

Discussing pertinent medical information (see 'Discuss pertinent information' below)

Ensuring adequate understanding of the information (see 'Assess comprehension' below)

Ensuring voluntariness of patient' or surrogate's decision (see 'Ensure voluntariness' below)

Jointly deliberating and obtaining the patient'/surrogate's agreement to a plan of care (see 'Deliberate jointly and obtain consent' below)

Assess decision-making capacity — Valid consent requires that the patient or surrogate have decision-making capacity. Individuals who lack decision-making capacity are unable to provide valid consent because they cannot adequately understand the choices available or the potential consequences of their medical decisions [9]. Such patients are frequently called incompetent but, strictly speaking, incompetence is a legal term and patients can only be deemed incompetent by the legal system. Incapacity is a clinical determination which is typically made by the treating clinician. Involvement of consultants in psychiatry should be considered in cases in which there is uncertainty about a patient's decision-making capacity, particularly when psychiatric illness is contributing to the uncertainty. Further details on assessing decision-making capacity are provided separately. (See "Assessment of decision-making capacity in adults".)

It is important to remember that patients who acutely lose the capacity to make an informed decision may regain capacity as their illness improves and/or the effects of medications wear off. Thus, patients who have been deemed incapacitated from a decision-making standpoint should be reassessed as subsequent decisions arise. Once the patient regains the capacity to make decisions, his or her wishes supersede the wishes of any surrogate or family members.

Discuss pertinent information — The clinician who will perform the intervention should engage the patient or surrogate in the process of informed consent. It is generally accepted that the informed consent conversation should include a description of the following: the intervention (including the personnel who will be participating), the potential benefits and risks of the intervention, reasonable alternatives (including no intervention), and the potential benefits and risks of these alternatives. This information should be communicated concisely and using terminology that the patient or surrogate can understand.

There is no single widely accepted standard for how much detail should be provided in the informed consent process. The goal is to be informative, but communicating every detail is neither possible nor practical. This is particularly relevant to communicating the risks of an intervention; generally speaking, adverse events that are either frequent or severe should be described.

The frequent ineffectiveness of informed consent conversations has become increasingly evident [10]. One study of informed consent in cardiology found that consent forms were complex, incomplete, and unreadable for the average patient [11]. Another study of patients providing informed consent for elective cardiac catheterization found that 88 percent of the patients had mistaken beliefs about the benefits of the procedure [12]. Reducing the amount of information conveyed while focusing on how and when the information is delivered, and perhaps using newer technology to improve traditional consent discussions, has the potential to "move informed consent away from a meaningless piece of required paperwork and toward a focus on patient autonomy and well-being" [10].

The law provides three different standards by which the adequacy of the information provided may be judged: the professional community standard, the reasonable person standard, and the subjective standard. It is often useful to consider if the information provided would pass all three standards if judged by an outside observer:

The professional community standard compares the information provided with that provided by other clinicians who are faced with the same or a very similar clinical situation. Such comparisons had previously been made with clinicians in the local community; however, these standards are increasingly being established by national professional organizations.

The reasonable person standard compares the information provided with that desired by a well-reasoning individual who is free of mental or physical illness and who has no conflicting interests in the outcome of the case. This standard varies based upon a number of factors, such as the cultural and educational background of the individual receiving the information.

The subjective standard requires the clinician to disclose the information that the individual particular patient deems important in the decision-making process. This standard allows information to be tailored to a specific clinical situation by the clinician.

A number of improvements in the informed consent process are under investigation. A systematic review identified 44 controlled trials of a wide range of interventions designed to improve patient comprehension in informed consent for medical and surgical procedures [13]. The main lessons from these studies are that more is not always better, discussions should take place well before the decision to undertake the intervention, and informing patients using a variety of methods will improve the quality of the discussion with the clinician [10,13].

While it is important that the pertinent medical information be provided to the patient or surrogate when obtaining informed consent, it is equally important that the clinician encourage and listen carefully to the questions and opinions of the patient or surrogate. Occasionally, patients or their surrogate will ask the clinician how many similar interventions he or she has performed and their success rate. Such questions should be answered truthfully. Complete and open communication between the clinician and the patient or surrogate promotes trust and cooperation.

Clinicians with potential financial conflicts of interest should disclose those conflicts to the patient or surrogate. As an example, a clinician who is seeking permission to use a medical device on a patient and owns the patent for the device (or stock in the company that makes it) should disclose the financial relationship. Failure to disclose such conflicts of interest leaves the clinician susceptible to accusations of impropriety.

Assess comprehension — The clinician should ensure that the information that was provided is understood by the patient or surrogate. A useful technique to assess understanding is to ask the patient or surrogate to summarize the information that has been conveyed and to clarify any misunderstandings.

Ensure voluntariness — A condition for valid informed consent is that the patient/surrogate is able to make decisions voluntarily, free from coercion or manipulation [14]. Coercion occurs when intentional threats or other actions substantially constrain patients' ability to choose freely. For example, a clinician might attempt to coerce a patient by stating that he/she will terminate the clinical relationship unless the patient undergoes a particular procedure. Manipulation involves attempts to influence patients' choices through behaviors such as withholding information or lying. An example of manipulation in the intensive care unit (ICU) context is a clinician who intentionally withholds information about the risks of placing a central venous catheter when discussing the procedure with a surrogate of a patient.

Deliberate jointly and obtain consent — Once the appropriate information has been provided, questions have been answered, and comprehension has been confirmed, the clinician should ask the patient or surrogate whether they grant permission for the intervention to be performed. Patients or surrogates usually ask for the clinician's opinion before giving final consent, in which case the clinician should render their opinion regarding the proper course of action. Decisions of this magnitude are best made jointly by those who have in-depth knowledge of the patient's values and wishes and those who understand the pertinent medical issues [15]. A set of facts should not be presented to the patient or surrogate without professional input and advice. The emphasis on patient autonomy has created the temptation for clinicians to shift the burden of decision-making entirely to patients or surrogates; we believe that this is an incorrect approach and that obtaining informed consent often requires genuine conversation and deliberation between the clinician and the patient or surrogate.

Occasionally, the decision made by a surrogate seems contrary to the patient's best interests and/or the clinician's expectation. In such cases, the clinician must be certain that no outside influences have caused the surrogate to deviate from the patient's true wishes. This can be difficult to assess and requires that the clinician explore the motivation for the surrogate's decision. As an example, the clinician might say, "can you tell me a little about why you believe that your father would not want the procedure?" Ongoing communication with family members usually allows clinicians to identify situations in which the patient's well-being is not the surrogate's primary concern. In such cases, clinicians will need to involve the hospital ethics committee and, in extreme cases, involve legal action to ensure that the patient's best interests are the primary driver of clinical decision-making.

Documentation — Clinicians should carefully document any informed consent discussions, regardless of whether consent was ultimately obtained. Documentation should include the date and time of the conversation, the identity of individuals who participated in the discussion, and the benefits and risks of the intervention and alternative interventions that were described. Finally, the clinician should document that the patient or surrogate understood the information, was given the opportunity to ask questions, and either agreed to proceed with the intervention or declined the intervention. If the patient declined the intervention, it should also be documented that the risks of not undergoing the intervention were described. If the intervention is performed without informed consent due to an emergent situation, the precise circumstances for the intervention should be documented in detail.

FOREIGN LANGUAGE SPEAKERS — Informed consent should be obtained in the patient's native language using an interpreter, preferably one who is familiar with medical terminology. This is necessary to insure that the patient understands the information being conveyed by the clinician and is able to ask questions in the way that he or she intends. Family members should not be used to interpret information because they may filter the information in order to protect the patient and this may impede the patient's ability to make an informed judgment.

APPROACHES TO INFORMED CONSENT — There is substantial variability in how clinicians approach informed consent for common procedures in intensive care units (ICUs), and there is ethical controversy about what is sufficient. The three most common approaches are:

Informed consent for each procedure – In this approach, the clinician obtains informed consent for each proposed intervention at the time of the procedure, engaging the patient or surrogate in a conversation as described above (see 'Process of informed consent' above). The main benefits of this approach are that it adheres closely to the theoretical ideal of informed consent and that it allows individuals to consider the procedure in light of the specific condition of the patient at the time. The main drawbacks are that it is time-intensive and sometimes will result in situations in which no consent can be obtained because circumstances may necessitate emergently performing the procedure.

Anticipatory bundled consent for specific procedures Anticipatory bundled consent for specific procedures entails obtaining written consent upon ICU admission for specific procedures before the procedure is actually needed. As an example, a trial compared standard informed consent with an approach in which, upon ICU admission, patients or surrogates were provided a universal consent form for eight common ICU procedures, as well as information about the risks and benefits of each procedure [16]. They found that bundled consent resulted in higher rates of obtaining written informed consent for actual procedures performed (90 versus 53 percent, respectively) and comparable levels of comprehension among consenters regarding the indications for and risks of procedures. The main drawback of this approach is that it may discourage the kinds of ongoing communication between the clinicians and patient or surrogate that is the hallmark of genuine informed consent. Moreover, obtaining consent before a procedure is even being considered risks that the consent is not truly informed because it does not allow consideration of the patient's actual condition and how that may affect the risk-benefit ratio.

Blanket consent for all "routine ICU interventions" – The third approach is to assert that certain invasive procedures are a part of routine ICU care and are therefore covered by a "blanket consent" form that patients or surrogates generally sign upon admission consenting to treatment in the hospital. Blanket consent forms broadly cover almost everything a doctor or hospital might do without mentioning anything specific [16]. The argument offered in favor of "blanket consent" being ethically adequate is that it is accepted (and practically necessary) that ICU clinicians routinely do many things without consent (eg, ventilator mode changes, decisions about pursuing imaging studies, frequent blood pressure monitoring, temperature monitoring via rectal probe, decisions to extubate a patient who passes weaning tests), that there are not adequate differences between these interventions to justify requiring informed consent for the latter group, and that it would lead to substantial inefficiencies in care to require detailed conversations and written informed consent for the myriad decisions that occur daily in ICUs. The ethical difficulties with this approach are that this practice differs with that which occurs outside the ICU, that there are sometimes alternatives to these procedures that reasonable patients might choose, and that blanket consent does not actually achieve the ethical goals of informed consent because patients/surrogates are not informed about the specific procedure that will be performed on them.

Institutions should establish guidelines for how informed consent will be obtained for procedures in ICUs. Although there is controversy about whether the signature of a patient or surrogate should be obtained on a formal consent document for common ICU procedures, there is broad agreement that all invasive procedures should be discussed with the patient or surrogate as part of the ongoing process of communication that defines truly informed consent [17].

ACTUAL PRACTICE IN ICUS — There are limited data addressing whether and how informed consent is obtained for routine intensive care unit (ICU) procedures such as central venous catheter placement, arterial catheter placement, thoracentesis, and bronchoscopy for airway clearance. Practices range from obtaining written informed consent at the time of each procedure to using the blanket hospital consent to treatment to cover common ICU procedures. In a national survey of critical care training program directors, 34 percent reported using blanket consent to cover common ICU procedures. The rates of obtaining written informed consent varied widely: 5 percent for placement of indwelling urinary catheters, 51 percent for arterial catheterization, 65 percent for central venous catheterization, 81 percent for thoracentesis, and 85 percent for bronchoscopy [18].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Intensive care unit ethics".)


Informed consent is a process of communication between a clinician and a patient or surrogate decision-maker that results in the patient agreeing or refusing to undergo a specific medical intervention. (See 'Introduction' above.)

The primary ethical justification for obtaining informed consent from patients is to respect their right to determine what happens to their bodies (ie, respect for autonomy). This entails a right to approve or refuse treatments that clinicians judge to be medically reasonable. Patients who lack the capacity to make an informed decision (eg, due to the critical illness or medications) are unable to participate in medical decision-making because they cannot understand the choices available or the potential consequences of their medical decisions. Instead, the medical team and persons who are most acquainted with the patient (eg, family) should attempt to reconstruct the patient's judgment by analyzing their prior statements, values, and beliefs. This is referred to as "substituted judgment." (See 'Justification for informed consent' above.)

The process of obtaining informed consent entails three steps: providing pertinent medical information about the proposed treatment and the reasonable alternatives, including no treatment; ensuring that the patient or surrogate has adequately understood the information; and deliberating with the patient/surrogate and then obtaining permission to perform the intervention. Clinicians should document any informed consent discussions, regardless of whether consent was ultimately obtained. (See 'Process of informed consent' above.)

There is substantial variability in how clinicians approach informed consent in intensive care units (ICUs), and there is ethical controversy about what is sufficient. The three most common approaches are obtaining informed consent for every intervention at the time of the procedure; anticipatory bundled consent for procedures, which entails obtaining written consent after ICU admission for specific procedures that may occur during the ICU stay; and blanket consent, which asserts that the consent form that patients/surrogates sign upon hospital admission consenting to hospital admission also covers consent for certain invasive procedures that are part of routine ICU care. Although there is controversy about whether the signature of a patient or surrogate should be obtained on a formal consent document for common ICU procedures, there is broad agreement that all invasive procedures should be discussed with the patient or surrogate as part of the ongoing process of communication that defines truly informed consent (See 'Approaches to informed consent' above.)

An exception to the requirement for informed consent occurs when an emergent, life-saving procedure is required and delaying the procedure to obtain consent would likely result in serious harm to the patient. (See 'Emergency exception to the requirement for informed consent' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges John Kellum, MD, who contributed to an earlier version of this topic review.

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