the european clinical trials directive includes a provision for informed consent from the patient or proxy consent from a legal representative in drug trials . although there is no doubt that informed consent is a valuable tool to protect patients ' rights in clinical trials , it is only very rarely possible to obtain a valid informed consent in emergencies , where a life - saving intervention is required within seconds to minutes . if pursued , and the consent is obtained from either the patient or a proxy , it can not be considered valid ; because of the obviously stressful situation , absence of duress can not be pre - supposed , either with regard to a patient 's or a relative 's ( proxy ) consent . in contrast to the most recent revision of the declaration of helsinki , the european directive offers no means of exemption from this requirement . thus , while the requirement of informed consent hampers clinical trials on potentially life - saving drugs in critical care settings , it does not protect the patient 's rights in this context . informed consent is instituted in human experimentation in order to respect the autonomy of the research subject . autonomy is a presupposition of agency and solely refers to agents who can understand and choose what they do . informed consent is not in itself an ethical principle , but an important procedure that permits human experimentation with the aim of benefiting society and future patients , without violating the basic rights of research subjects . however , since both medical treatment and , consequently , medical research also extend to those with incomplete autonomy , such as incapacitated critically ill patients , respect for autonomy can not be considered the only or most important ethical principle . other principles that express the basic rights of the research subject must be considered . in ethical terms , these basic rights are expressed in the ' categorical imperative ' , which states that any human being possesses an inherent value and dignity and must be treated with respect , and therefore ' always at the same time as an end and never merely as a means to an end ' . to sustain this principle in subjects with incomplete autonomy that can not consent to research , these subjects must be ensured adequate protection that reflects their vulnerability . instead of insisting on a prospective informed consent regardless of the context , it may therefore be worthwhile to accept the premise that informed consent or proxy consent can not be obtained in all types of research . it is by no means a sine qua non , and comprises only one of three ethically relevant elements in human experimentation , the other two being risk assessment and selection of research subjects . with regard to risk assessment , thus , higher risks are accepted when the subject is capable of providing a valid informed consent . in accordance with the principle of extra protection to patients with in - complete autonomy therapeutic procedures are study interventions instituted with the intent of providing direct benefit to the patient . in drug trials , therapeutic procedures comprise the administration of drugs that have the prospect of benefiting the patient . these must pass the test of clinical equipoise , which signifies that the two interventions are roughly equivalent , in the sense that a genuine uncertainty concerning the comparable merits and disadvantages of each trial arm exists in the expert medical community . the potential risks of these interventions are thus to be considered in light of their potential benefit for the individual patient . non - therapeutic procedures are those interventions that are not instituted with therapeutic intent and are only intended to answer scientific questions of the study , such as additional laboratory tests and imaging to monitor treatment effects in detail . since the patient can not consent to these risks , these must be reduced to minimal risks . minimal risk implies that the probability and magnitude of harm or discomfort anticipated in the trial are not greater than those encountered by normal persons in daily life ; a routine physical examination with blood sampling is considered a classical example of a procedure that involves a minimal risk . since the risks of the therapeutic procedures are unaffected by trial participation , the only additional risk imposed by inclusion in the trial is equivalent to that associated with a routine physical examination . as previously stated by charles weijer in critical care , such a risk assessment that distinguishes therapeutic from non - therapeutic components of the study shifts the focus from the potentially deleterious complications of critical illness per se to the actual risks imposed by participation in the study . as for the selection of patients , the requirement of adequate protection entails that exploitation of these patients as easily accessible research subjects due to their impaired autonomy must be prevented . thus , the overall aim of the research must be to specifically improve care of this patient group . furthermore , it must be essential to the design and conclusions of the research that it is conducted under circumstances where it is by no means possible to obtain a valid informed consent . if we want treatment of critically ill patients to be based on evidence - based principles , it is necessary to change the european directive so that drug trials can be initiated under circumstances where it is impossible to obtain a valid informed consent from either the patient or a proxy . it is paramount that we ensure adequate protection of the individual patient in such studies , which is achieved by focusing on the scientific content , rather than the consent , which is neither sufficient nor necessary . the ethical review boards should be equipped to determine whether participation in a trial is by any means contrary to the best interest of a given patient , by critically reviewing and monitoring study protocols in which a waiver of consent is deemed necessary . this permits clinical trials in critical care settings while ensuring that the individual patient is treated respectfully in accordance with the categorical imperative .
the european clinical trials directive requires an informed consent from the patient or a proxy in drug trials . 
 although informed consent is a valuable tool to protect patients ' rights in clinical trials , this requirement largely impedes research in critical care settings , and if pursued in this context , it does not provide the patient with adequate protection . instead of insisting on informed consent 
 , we suggest that the focus should be shifted towards two other ethically relevant elements in human experimentation : risk assessment and selection of research subjects . 
 when reviewing protocols in which a waiver of consent is deemed necessary , the ethical review board should ensure that non - therapeutic risks are minimal , that the research is specifically designed to benefit critically ill patients , and that it can not be conducted under circumstances where an informed consent can be obtained . if the european directive is changed accordingly , this permits clinical trials in critical care settings , while adequate protection from risky non - therapeutic procedures is ensured and exploitation of the patient as an easily accessible research subject is prevented .