To do so would violate clinical equipoise, the situation in which genuine uncertainty exists about whether an untested treatment has benefits or risks that exceed those of conventional care.
RCTs require a setting of equipoise, a situation where both patients and clinicians feel a genuine conscious uncertainty as to the optimal management strategy.
In this situation equipoise applies (i.e. the technique has been introduced without definite evidence but opinion regarding its use is not yet solidified) making the need for a trial even more urgent.
We believe that the situation of equipoise prevailing now is different from that prevailing before the publication of the two RCTS on ICU patients and the combined analysis made here.
Additionally a situation of equipoise currently exists, whereby clinicians can see the potential benefits of ECMO, but do not have enough evidence to make an informed choice as to the best treatment for their patient.
In very early times of clinical trials some people argued that in the situation of equipoise the informed consent of the patient may weaken the scientific rigor of the trial because of potentially biased samples, early dropouts, patients' knowledge about possible side effects, and so on.
A situation of clinical equipoise is especially difficult to achieve in placebo-controlled clinical trials, and also when a new drug under development is compared with a commercialized drug.
In situations of clinical equipoise, also known as preference-sensitive decisions, it is widely argued that individual patient preferences [ 7] should become the guiding principle for patients making informed decisions together with their healthcare providers [ 8].
In practice, these considerations would lead clinicians and patients towards something very like equipoise, save in those happy situations in which there is close concordance between the interests of patients, clinicians, triallists and sponsors.
