Time-Limited Trials in Intensive Care Medicine: A Tool for Avoiding Inappropriate Treatment

Approximately 16% of patients treated in intensive care units do not outlive the treatment. Among patients in intensive care units who undergo mechanical ventilation or dialysis, only half survive longer than six months. Prognostication is unreliable in the individual case. Time-limited trials (TLT) may help prevent inappropriate treatment, particularly for older and chronically ill patients.

This review is based on pertinent publications that were retrieved by a selective search in the PubMed and Scopus databases and the Google Scholar searching service.

19 empirical studies and 15 medical-ethical analyses on time-limited trials were identified, as well as expert opinions, guidelines, and review articles. If the prognosis of a patient in intensive care is poor or unclear, the patient or representative can agree with the treating team on a trial of predefined treatment, for a limited period of time, to attain objectifiable, individual therapeutic goals. These goals are set and assessed with the aid of scores used in intensive care medicine, along with the patient's individual values and resources. TLTs enable more accurate prognostication based on the observed effect of treatment in the individual patient, so that a joint decision can be taken on whether to provide further treatment with curative intent or to switch to palliative care. In this way, inappropriate treatment can be avoided-both over- and undertreatment. Initial findings suggest that TLT can identify patients who will not benefit from continued intensive treatment.

TLTs are well founded in medical ethics and address a central problem in intensive care medicine, namely, the question of individual benefit. Only sparse empirical data on TLTs are available to date. TLTs should be standardized and evaluated in prospective studies to determine whether their expected benefit can truly be achieved in the complex real world of intensive care medicine.