Bao, T., Ye, X., Skinner, J., Cao, B., Fisher, J., Nesbit, S., & Grossman, S.A. (2011). The analgesic effect of magnetic acupressure in cancer patients undergoing bone marrow aspiration and biopsy: A randomized, blinded, controlled trial. Journal of Pain and Symptom Management, 41(6), 995–1002.

To compare the analgesic effect of applying magnetic acupressure to the L14 point to that of applying magnetic acupressure to a sham point

Patients were stratified by the number of prior bone marrow aspiration biopsies (BMABs) and randomized to one of two groups. In the first group, a practitioner delivered acupressure to the L14 acupoint (the dorsum of the first interosseus space of the hand). In the second group, a practitioner delivered acupressure to a sham point (the fourth interosseus space of the hand). Two HACI magnetic acupressure suction cups (HMASCs) were applied to the designated area of both the patient's hands for the duration of the BMAB procedure. The same two HMASCs were used on all study patients. All patients received standard local analgesics as ordered by the BMAB provider. The same BMAB provider and acupressure practitioner were used throughout the study. The patient, BMAB provider, and outcome evaluator were blinded to the location of the acupressure. The patient’s pain intensity was measured at baseline and after the BMAB.

• The sample was composed of 77 patients, 37 in the L14 group and 40 in the sham-point group.
• Mean patient age, in both groups, was 57 years (SD = 12.4 years).
• Of all patients, 61% were  male and 39% were female.
• Authors did not cite disease characteristics.
• Of all patients, 82% were Caucasian (authors noted no other races). Of the L14 group, 31% had had more than one BMAB; of the sham-point group, 75% had had more than one BMAB.

• Single site
• Inpatient and outpatient
• Locations associated with the Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore
   

Multiple phases of care

Single-center randomized single-blind clinical trial

• Visual analog scale (VAS) of 11 points, to measure baseline pain score and score post-BMAB (The patient was asked to rank the worst pain experienced during BMAB.)    
• Measures of the use of analgesic or anxiolytic medications in the 12 hours preceding the BMAB (Data were gathered by means of questioning patients.)
• Post-BMAB data reflecting patients' opinions about the effectiveness of the acupressure in pain relief
• Measures of acupressure side effects

Authors noted no significant difference in median pain scores between the patients treated at the L14 site versus the sham site (3.0 versus 3.0, p = 0.08, Mann-Whitney test). Eight patients (20%) in the sham-site group experienced severe pain. One patient (2.7%) in the L14 group experienced severe pain (p = 0.03, two-tailed Fisher’s exact test). The unadjusted risk of patients experiencing severe pain in the sham-site group was nine times higher (95% CI 1.07–75.9, p = 0.04). After accounting for age, number of prior BMABs, baseline pain scores, and the number of times the cup fell during the procedure, patients in the sham-site group were more likely to experience severe pain than were those in the L14 group (risk ratio 9.3; 95% CI 1.01–85.6; p = 0.049). The acupressure point was the only statistically significant factor associated with BMAB-related pain.

Magnetic acupressure delivered at L14 may reduce the number of patients who experience severe pain during BMAB.

• The study had a small sample, with fewer than 100 participants.
• Generalizability of findings is limited because data were collected at only one study site and by only one BMAB operator and because one acupressure practitioner delivered the study procedure. In addition, pain was measured after the procedure rather than during the procedure. When this measurement occurred is unclear.

The combination of magnetic acupressure at the L14 site and local anesthetics may reduce severe pain during BMAB. Acupressure is inexpensive, and it requires minimal training to deliver.