Does Trans-Cutaneous Electrical Nerve Stimulation (TENS) Alleviate The Pain Experienced During Bone Marrow Sampling?

Patients in whom a bone marrow biopsy is planned will be randomised to one of two groups - a control-TENS group where the TENS machine will be set at the lowest sensory threshold and an intervention-TENS group where the TENS machine will be set at a recognised analgesic level (>50 Hertz (Hz) and below the pain threshold for the patient) (Bennett et al. 2011). The identity of the TENS type will be concealed from both the patient and the doctor performing the biopsy. The primary outcome will be pain and this will be recorded by the patient immediately after the procedure using a validated numerical scale (0-10). All patients will receive standard pain relief (ie. local anaesthetic with or without inhaled nitrous oxide).

The benefit of this study is to establish whether or not TENS can benefit patients as an additional, safe, non-invasive and inexpensive method of pain relief during this frequently painful procedure.

Inclusion criteria

• Participant is willing and able to give informed consent for participation in the study.
• Male or Female, aged 18 years or above.
• Participants are those medical patients seen in the haematology outpatients clinic for whom a bone-marrow trephine biopsy is deemed necessary either for diagnosis, staging or disease monitoring purposes. Participants are either new patients or routine follow ups.
• Participant is able (in the Investigators opinion) and willing to comply with all study requirements.
• Participant is willing to allow his or her General Practitioner to be notified of participation in the study.

Exclusion criteria

• Any known adverse reaction to high-frequency TENS or electrode gel pads
• Any significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the study, or may influence the result of the study, or the participant's ability to participate in the study.