Efficiency and Safety of a Procedural Sedation by Propofol on Terminally Ill Patients With Refractory Pain

At the end of life, some patients may feel pain during care procedures. These painful procedures contribute to the patient's overall suffering. Of course the investigators do not take into account procedures which could be considered as futile medical care and would not bring any comfort to the patient. The procedures that the investigators do consider are necessary and acceptable: basic hygiene care, such as bandaging. Even with the best palliative care, certain pains caused by these procedures can be refractory to analgesics, to Entonox and to other conservative treatments. These pains are ethically unacceptable, especially at the end of life. In these cases, short-term procedural sedation could benefit the patient, as indicated by the Agence Nationale de Sécurité du Médicament (French Agency for the Safety of Health Products). However, there are no documented recommendations on the way to administer these types of sedations because of a lack of scientific studies in that field. It therefore remains an important issue in palliative care research. The sedations consist of a transitory reduction of vigilance which is sufficient enough for the patient not to suffer. They are therefore a major tool to provide sufficient comfort to terminally ill patients while being used as part of a treatment approach. However, they still have drawbacks: patients lose contact with the environment but can also experience respiratory complications (embarrassment, respiratory depression, inhalation). These risks compel the investigators to only use these sedations for terminally ill patients suffering from major refractory pain at the end of life, in which case they consider that comfort is an absolute priority (principle of double effect). The decision to use sedation must be agreed upon after collegial consultation and discussion with the patient and/or his or her relatives. The risk of side effects must be reduced as far as possible without pursuing a reanimation approach which would go against a palliative approach.

Sedation, which was originally exclusively administered by anesthesiologists, has been used by palliative care doctors for many years. At first, midazolam seemed to be the best sedative agent and its use spread although it has not been much documented in that context. However, midazolam has its limits. It cannot provide a very deep sedation because of its respiratory depressant effect and the patient, when under light sedation, often experiences persistent discomfort. Moreover, midazolam requires a long titration period and often causes a sedation which can last several hours, thus reducing the patient's relational life and increasing the risk of congestion and respiratory depression. Investigators are therefore looking for alternatives. According to them, propofol would be a suitable molecule because of its pharmacological properties. Its pharmacokinetic properties allow the patient not only to quickly reach deep sedation and therefore better comfort, but also to wake up as soon as the painful care procedure is completed, thus limiting the risk of respiratory side effects.

Note that it is already used in other situations for procedural sedation by doctors who are not anesthesiologists (pulmonologists, gastroenterologists, emergency doctors).

In a feasibility study, investigators pointed out that propofol could be used in a palliative care unit for transitory sedation administered by an anesthesiologist following a strict protocol and could relieve terminally ill patients at the end of life during painful care procedures in a sufficiently safe way (preliminary results presented at the French Society of Support and Palliative Care conference in 2015).

Investigators aim at showing that a procedural sedation using propofol can be administered by palliative care doctors who are not anesthesiologists but have been trained to follow a precise protocol and that it can bring relief to terminally ill patients with refractory pain experienced during care procedures without causing major side effects.