Nurse Initiated Auricular Acupressure for Post-operative Pain Control in Patients Undergoing TKA or THA: A Randomized Controlled Trial

Introduction

Postoperative pain management has become an area of concern since the use of opioids as a primary pain management strategy in the post-operative period may promote the misuse or abuse of opioids in the outpatient setting (Hah, et al., 2017; Varady et al., 2021). According to the American Joint Replacement Registry (2022), over 2.5 million hip and knee arthroplasty procedures (THA and TKA) have been done since 2012 with continued growth in the number of procedures performed each year across the world (Abdelaah, 2020). According to Cook et al. (2019), as many as 10% of THA and 13% of TKA patients may still be taking opioids 1 year after surgery, despite being opioid naive on the day of surgery. Among patients who reported opioid use prior to surgery, 47% of THA and 62% of TKA patients reported using opioids 1 year post surgery (Cook et al., 2019). Non-pharmacological therapies that can be employed independently by nurses in the provision of post-operative care may prove beneficial in decreasing the reliance on opioids.

Beginning in 2018, the Joint Commission (2017) required accredited hospitals to offer non-pharmacologic pain treatment modalities. Listed in this directive, were several complementary strategies such as acupuncture, massage, and relaxation therapy. Although auricular acupressure was not specifically listed, as a derivative of acupuncture and a commonly used massage technique, auricular acupressure may be an effective non-pharmacologic adjunctive strategy for THA and TKA patients needing post-operative pain control (He et al., 2013).

Acupuncture and acupressure have been used for centuries in the management of a variety of disorders including pain (Patil et al., 2021). Auriculotherapy refers to the use of either acupressure or acupuncture to stimulate acupoints on the ear. Although auricular acupuncture/acupressure’s mechanism of action for pain reduction has not been fully elucidated, several clinical studies have demonstrated that both auricular acupuncture and auricular acupressure are effective in reducing post-operative pain. In a randomized controlled trial (RCT) of patients undergoing TKA, He and colleagues (2013) studied the impact of auricular acupressure on post-operative patient controlled analgesia (PCA) use. Although they did not see a significant reduction in pain scores, they did see a significant reduction in PCA dose. Chang and colleagues (2012) had similar results, with a reduction of total analgesia (morphine) through post-operative day 3 after TKA.

Auriculotherapy’s potential effectiveness in the treatment of pain has also been demonstrated by meta-analyses (Asher et al., 2010; Li et al., 2023; Yeh, et al., 2014, and Zhong et al., 2019). A recent meta-analysis (Li et al., 2023) found auricular acupressure combined with conventional pain management was superior to conventional treatment alone in the management of post-operative pain after surgical repair of a hip fracture. A 2014 systematic review of 13 auriculotherapy trials in the US and China (Yeh et al., 2014) found that when compared to auricular acupuncture and auricular electroacupuncture, auricular acupressure had the best evidence of efficacy for pain. The authors postulate that the advantage of auricular acupressure is the self-efficacy afforded by the ability of the patient to stimulate the points themselves as needed. A recent meta-analysis of 26 RCTs (Zhong et al., 2019) favored the use of auricular acupressure for post-operative pain management over usual care based on total effective rate (RR=1.25, [CI= 1.13, 1.37], p <.0001) and total analgesia use (RR=0.41, [CI= 0.24, 0.68] p = .0006). The studies included in their review varied by type of surgery and the acupoints employed for pain reduction. There were no serious adverse events reported in the 26 trials (N=1063 in treatment groups).

Unlike acupuncture, auricular acupressure does not involve needles, it can be easily applied with training, patients may be more open to its use and can self-manage their pain by applying pressure as needed (Yeh et al., 2014). Auricular acupressure is within the scope of practice for many nurses in the U.S. and elsewhere (American Holistic Nurses Association, 2021)—making this an intervention with potential to reach many patients.

The purpose of this study was to assess the feasibility of nurse delivered acupressure using the battlefield auricular acupressure protocol for the management of post-operative pain in patients having either TKA or THA. The aims of this study are as follows:

1. To evaluate the feasibility of nurse-initiated auricular acupressure for post-operative pain management to include: a) patient satisfaction, b) acupressure device adherence, c) patient engagement with intervention, and d) nurse time,

2. To estimate the impact of auricular acupressure applied in the immediate postoperative period on: a) inpatient and outpatient opioid intake, b) average AM pain score, and c) average worst pain of the day score through post-operative day 4 (POD-4).

Materials and Methods

Design, setting and sample

This was a randomized controlled feasibility trial of nurse initiated battlefield auricular acupressure (BAA) compared with usual care. The study took place in a community hospital specializing in orthopedic surgeries that is part of a larger healthcare system in the mid-Atlantic region of the United States. Eligible patients were between the ages of 18 and 80 undergoing either TKA or THA with an American Society of Anesthesiologists (ASA) physical status classification of <IV and morphine milligram equivalence (MME) score < 50 at the time of surgery (ASA, 2020). Patients with a history of cognitive impairment, delirium episode, atopic skin disease or latex allergy were excluded from the study. Based on published literature (He et al., 2013), a total sample size of 50 was needed (25 each arm) to detect a 30% reduction in total MME use and a 1.5 point difference in pain as recorded on a visual analogue scale (alpha= 0.05, power > 80%). Recruitment target was 30 in each arm to allow for attrition. The study was approved by the Institutional Review Board for the healthcare system.

Materials

Auricular acupressure devices come in a variety of styles, including the traditional 2 mm vaccaria plant seed, spherical metal pellets and spherical magnets affixed to an adhesive pad (see Figure 1). For this study, vaccaria seeds were used since these seeds are not metal and would not be a concern if an MRI was needed. All seeds were purchased in bulk through an acupuncture vendor.

Figure 1.

Acupressure seeds placed on adult ear. Right hand side, Vaccaria seed on adhesive pad and tray containing seeds.

Battlefield Auricular Acupressure (BAA) Protocol

There are currently no universally accepted auriculotherapy protocols across or within specific pain populations. Battlefield auricular acupuncture (BFA) is a standardized protocol for both acute and chronic pain developed by Richard Niemtzow, a retired U.S. Air Force physician, based on the work of French physician Paul Nogier (Taylor et al., 2021). BFA utilizes 5 acupoints on the ear that are thought to be involved in central processing of pain. Dr. Niemtzow’s protocol has been used in the U.S. military in the treatment of pain for over 15 years as well as The Veterans Health Administration (VHA)(Taylor et al, 2021). More recently, in an effort to increase access to non-pharmacological modalities for pain management, the VHA has developed a battlefield auricular acupressure (BAA) protocol. The BAA protocol uses the same acupoints as the BFA protocol but instead of piercing the skin with needles, acupressure devices (seeds, metal pellets or magnets) are placed on the acupoints, and stimulation of the points is achieved when pressure is applied to the device.

The original BAA protocol calls for the placement of acupressure devices to both ears in the following order using the acronym CTOPS: 1) Cingulate gyrus, 2) Thalamus, 3) Omega 2 4) Point zero, and 5) Shen men (U.S Air Force, 2021) (see Figure 1). After placement, pressure is applied to the acupressure device, prior to placing the next acupressure pad with reassessment of the pain score before moving to the next acupoint. For this study, the protocol was modified by having the nurses place all acupressure devices in the order noted above. Once all acupressure devices were placed, the nurse applied pressure directly over the seed using their index finger and asked the patient to indicate when they noted tingling, mild-to moderate tenderness, or warmth. The patient was given a picture of a right and left ear labeled with the points and asked to follow along with the nurse while the seeds were being placed and activated. Patients were instructed by nurses on how to apply pressure with return demonstration by the patient. Pressure was applied in CTOPS order. Once noted, pressure was applied to each device for 30 seconds in the CTOPS order. Following surgery, patients were instructed to apply pressure in the CTOPS order 3 times a day, for 30 seconds to each device, through the end of POD-4.

Training of nurses in BAA

Two medical acupuncturists and a licensed acupuncturist trained 5 registered nurses who worked in the holding room in the modified BAA procedure and protocol. The lead acupuncturist and trainer for BAA at the VHA served as a consultant for the training. Competency was confirmed by assessment of knowledge (written assessment) and direct observation, by acupuncturists, of the nurse’s ability to correctly identify auricular acupressure points through visual inspection, proper application of acupressure devices, proper activation of the acupoints via manual pressure applied to the acupressure devices and patient instruction in the care and activation of the acupressure devices.

Participant consent

Participants were informed of the study at the time of their surgical consult or at their pre-operative appointment. The study coordinator reviewed the electronic medical records (EMR) of patients who expressed interest in the study to confirm eligibility. Informed consent was obtained at the pre-operative assessment visit or on the day of surgery. No incentives were offered for study participation. Regardless of treatment group, all patients were informed they could take pain medications as prescribed. The standard post-operative pain medication protocol for both TKA and THA at this facility included oral oxycodone, celecoxib, and acetaminophen. For break through pain, some patients were given IV hydromorphone or oral tramadol.

Procedures

The nurse accessed the random group assignment when the patient arrived to the holding room, prior to surgery. The nurse then checked the EMR to confirm consent. Baseline pain score was recorded prior to any medication administration or acupressure device placement. For patients randomized to BAA, placement of the acupressure devices took place in the holding room prior to surgery. The ears were inspected for any barriers to placement, and the acupressure devices were placed bilaterally as noted earlier. All patients were provided a spiral bound diary with daily questionnaires to record pain scores, pain medications taken, seed/device adherence (treatment group), application of pressure (treatment group), and any comments they wanted to share.

The nurses visited all study patients after arrival to the floor post-surgery and on the day of discharge to ensure all acupressure seeds remained in place (treatment group) and to review instructions for completing the daily diary (both groups). On the last day of the study, patients were instructed to complete the diary indicating their satisfaction with pain management, likelihood of using acupressure in the future, and to provide any comments that might be helpful to the research team. Patients were instructed to remove the seeds before going to bed (end of POD-4), place the diary in a provided addressed stamped envelope and mail at their earliest convenience. All patients received either daily text message reminders or phone calls through POD-4.

Outcome measures-feasibility

Participant satisfaction was measured on POD-4 via patient diary. Participants were asked to rate their overall satisfaction with pain management using a 6-point forced choice format from “very dissatisfied” to “very satisfied”. Secondly, they were asked if they would “consider using auricular acupressure for pain management in the future if recommended by their nurse or physician” with the response choices of: “No, I would not use”, “Maybe”, or “Yes, I would definitely consider using in the future”.

Participant engagement was defined as their self-reported adherence to the protocol applying pressure to the acupressure devices 3 times a day for 30 seconds each for a total activation time of 15 minutes per day. We calculated activations from post-operative day 1 through the end of POD-4 for a total of 12 activations across 4 days. Activations were recorded in the diary with a check mark on a each time pressure was applied to the acupressure devices.

Seed adherence was defined as the number of seeds that remained in place at the end of POD-4 and calculated as a percent. Since a total of 10 seeds were placed (5 per ear), seed adherence was calculated as a percent of total using the following formula: ((number seeds remaining on POD-4) / 10 (total number of seeds placed)) * 100. Participants (treatment group) were asked to record daily if any seeds had fallen off and the location of the point(s). Any seeds that fell off during hospital stay were replaced, but once the patient was discharged, patients were instructed not to replace seeds and to record daily any missing seeds and location using a provided diagram.

Nurse time was measured in minutes from time nurse entered the room to place acupressure devices to when nurse exited the room. Nurses were provided a timer. If the nurse was interrupted by non-study related activities, they were asked to estimate this time and subtract from the total time recorded.

Pain and MME

Both inpatient and outpatient pain scores were measured using a visual analogue scale (VAS). VAS is a highly sensitive measure for pain in clinical research and may be easier for patients to use than numeric rating scales (Younger et al., 2009). Two pain scores were collected daily, “AM pain” was defined as pain upon arising in the morning and “Worst pain” was recorded in the evening before bed as the worst pain the patient experienced throughout the day. Patients self-reported their pain scores in their diary and marked when they applied pressure to the acupressure seeds. Patients were asked to record “AM pain” score, prior to taking any medications or applying pressure to the acupressure devices and to record their “worst pain” score. Patients were asked to place a mark along a 10 cm line to mark their pain anchored by “no pain” on the left and “worst pain” on the right. The line was measured in millimeters by the study coordinator using a provided ruler and recorded in millimeters. The resulting measure was converted to a 0-10 scale, by dividing the VAS recording in mm (10 cm = 100 mm) by 10. Average AM pain scores were aggregated over 4 days (post-op day 1 –POD-4) and average worst pain of the day scores were aggregated over 5 days (post-op day 0 –POD-4).

Inpatient opioid pain medication use was collected via the medication administration record in the EMR. Outpatient usage was self-reported daily in the patient diary. Inpatient and outpatient total opioid use was converted to total morphine milligram equivalents (MME)(U.S Department of Health and Human Services, 2020).

Data analysis

Statistical analyses were conducted with SAS 9.4 (Cary, NC) statistical software by a statistician blinded to the treatment group. Descriptive statistics were reported for patient characteristics, patient engagement in the intervention, adherence of acupressure devices to ears, and nurse time. Analysis of Covariance (ANCOVA) was used to compare MME or pain scores between treatment groups adjusting for age, sex, and type of surgery, baseline MME, and time in hospital (inpatient MME). ANCOVA was also used to determine average AM pain score and average worst pain of the day adjusting for age, sex, type of surgery, and baseline pain score. Linear mixed models were used to assess trajectory of MME consumption and pain scores over time adjusting for age, sex, type of surgery, baseline MME. An interaction term was added to the mixed model to determine if there were differences in response over time by intervention group. Alpha was set to <.05 for two sided tests in all analyses. Type III F statistic for the treatment arm and adjustedp values are reported unless stated otherwise.

Results

Ninety-one surgical patients responded to an advertisement for study participation and were assessed for eligibility (see Figure 2.). A total of 60 patients were randomized with a mean age of 66 (SD= 9.0). Most participants were White (93%), female (65%), and undergoing TKA (61.7%). There were no appreciable differences between randomization arms in regard to surgery type (knee or hip), age, race, sex, baseline pain score, or baseline MME score (See Table 1.). A total of 53 participants completed the study. Three in the intervention group and four in the control group had incomplete data after discharge (patient diary not received). One participant in the treatment group withdrew, but returned the questionnaire with partial data. No imputation was performed for missing data, and all available data were used for each analysis.

Figure 2. Participant Flow Diagram.

*1 patient stated that diary was returned, but not received by study staff.

Table 1.

Participant Characteristics

	BAA (n=30)	Control (n=30)
Age (SD)	66 (9.9)	66 (8.3)
Sex (%)
Male	10 (33)	11 (36.7)
Female	20 (67)	19 (63.3)
Race (%)
Black/African American	1 (3.3)	0
Native Hawaiian/Pacific Islander	1 (3.3)	0
White	27 (90)	29 (97)
More than one race	1 (3.3)	0
Not reported	0	1 (3)
Surgery Type (%)
THA	13 (43)	10 (33)
TKA	17 (57)	20 (67)
Discharge Day (%)
Post-op day 0	2 (7)	0
Post-op day 1	25 (83)	29(97)
Post-op day 2	2 (7)	1(3)
Post-op day 3	1 (3)	0
Baseline MME (SD)	0.5 (1.5)	0.7 (2.9)
Baseline Pain (SD)	2.30 (2.28)	2.84 (2.69)

Note. THA=total hip arthroplasty, TKA= total knee arthroplasty

Feasibility outcomes

Any degree of satisfaction or dissatisfaction was treated as being satisfied or dissatisfied with post-operative pain management. Of the 27 BAA patients who returned their study diaries only 19 responded to the question measuring their overall satisfaction with pain control. All 19 BAA patients reported being satisfied and 95.5% of the control patients who responded to the question were also satisfied (n=21). Twenty-one patients in the BAA group responded to the question whether they would use BAA in the future if recommended, with 90.5% responding they would “definitely consider” using in the future. Twenty-two in the control group responded to the same question, with 59% responding they would “definitely consider”, 36% responding “maybe”, and 1 person, responding “no”.

Engagement data were calculated for all 28 returned diaries. Two patients recorded no activations after post-operative day 1. Of the 28 participants, 15 (52%) applied 90% of prescribed activations, with 2 of those participants activating more than 3 times a day (counted as 3/per day in calculating percent). On POD-4, 24 of 28 (86%) participants reported activating the acupressure devices with a mean number of activations of 2.57 (SD = 1.1, range 0-4).

Of those reporting device adherence (n=25), 40% reported all pads were in place and 23% with 5 or more pads missing (range 1-10) on POD-4. In comparison, on post-operative day 3, 48% reported all pads in place, and only 8% had 5 or more seeds missing (range 1-8).

Nurse time for intervention was calculated for the 28 patients who had data reported The mean time recorded by the BAA nurses was 12.85 minutes (SD=2.92, range 6-18 minutes).

Pain and MME outcomes

Figure 3, displays the trajectory of pain scores and MME through POD-4. Patients in the BAA group had lower average pain scores than the control group (3.14 vs. 4.24. p < 0.048) in the ANCOVA model with the mixed model trending toward significance (p = .053)(See Tables 2 & 3). Women and older persons reported lower AM pain scores in both the mixed and ANCOVA models (ANCOVA: Women, Est = −1.68, SE = 0.62, p = 0.009; Age, Est= −0.07, SE = 0.03, p = 0.04). Although average worst pain of the day was lower in the BAA group, this did not reach significance in either ANCOVA or mixed models (See Tables 2. & 4.).

Figure 3.

Trajectory of pain scores and total opioid use in MMEs. Day 0 = day of surgery, PO = post-operative day

Table 2.

ANCOVA Adjusted Means for Total MME, Average Pain, Average Worst Pain

	BAA M (SE) n = 28	95% CI	Control M (SE) n = 27	95% CI	p Treatment Effect
Inpatient MME*	37.32 (4.46)	28.38, 46.27	36.21 (4.46)	27.27, 45.15	p = 0.86*
Outpatient MME**	77.58 (11.90)	53.62, 101.53	85.46 (11.87)	61.58, 109.35	p = 0.64**
Total MME	114.30 (14.57)	84.97, 143.64	122 .38 (14.53)	93.13, 151.63	p = 0.64
Average Worst Pain	5.35 (0.44)	4.47, 6.24	6.03 (0.45)	5.13, 6.93	p = 0.29***
Average AM Pain	3.14 (0.37)	2.37, 3.90	4.24 (0.38)	3.47, 5.02	p = 0.048***

Note. M= Adjusted mean; SE= Standard Error; CI= confidence interval;

^*Adjusted for sex, surgery type, age, time in hospital, baseline MME;

^**Adjusted for sex, surgery type, age, baseline MME;

^***Adjusted for sex, surgery type, age, and baseline pain score.

Table 3.

Daily AM Pain Scores Mixed Model

Post-op Day	BAA M (SE) n = 28	95% CI	Control M (SE) n = 27	95% CI	p
1	3.16 (0.44)	2.29, 4.04	3.78 (.45)	2.89, 4.67	p =.053
2	3.78 (0.45)	2.90, 4.67	4.90 (.45)	4.00, 5.78
3	2.63 (0.46)	1.76, 3.58	4.34 (0.45)	3.46, 5.23
4	2.89 (0.47)	1.96, 3.80	4.03(0.46)	3.13, 4.93

Note. Adjusted means (M) from mixed model, adjusted for age, sex, surgery type, and baseline pain.

Table 4.

Daily Worst Pain of the Day, BAA vs. Control Mixed Model

Post-op Day	BAA M (SE) n = 28	95% CI	Control M (SE) n = 27	LCI, UCI	p
1	5.82 (0.53)	4.78, 6.86	6.34 (0.54)	5.28, 7.40	p = 0.26
2	5.73 (0.53)	4.69, 6.77	6.43 (0.53)	5.35, 7.48
3	4.90 (0.54)	3.83, 5.96	6.22 (0.53)	5.17, 7.27
4	4.57 (0.55)	3.48, 5.66	5.50 (0.55)	4.42, 6.58

Note. Adjusted means from mixed model, adjusted for age, sex, surgery type, and baseline pain.

Although total MME consumption over 5 days (day of surgery - POD-4) was lower in the BAA group, this were no significant differences any of the models (See Tables 2. & 5.). In the mixed model, there was no significant interaction between time and treatment group; however, there were significant differences in MME consumption between days (F = 14.57, p < .0001).

Table 5.

Daily MME BAA vs. Control, Mixed Model

Post-Op Day	BAA M (SE) n = 28	95% CI	Control M (SE) n = 27	95% CI	p
0	15.82 (3.40)	9.11, 22.53	18.28 (3.41)	11.56, 25.01	F = 0.20 p = 0.66
1	34.07 (3.52)	27.12, 41.02	31.95 (3.53)	24.99, 38.90
2	27.53 (3.56)	20.50, 34.56	27.03 (3.57)	20.00, 34.07
3	20.57 (3.63)	13.42, 27.72	22.77 (3.58)	15.70, 29.83
4	14.35 (3.65)	7.15, 21.55	20.39 (3.63)	13.22, 27.56

Note. M= adjusted means, SE = Standard Errors from mixed model. Adjusted for age, sex, baseline MME, type of surgery.

Discussion

The findings of this feasibility study demonstrate auricular acupressure can be incorporated into the standard nursing care of surgical patients while in the holding room. Patients were receptive to the intervention. There is some evidence that perceived pain may be less in those using auricular acupressure than usual care, but it may not impact opioid intake within the first 4 days of surgery. One benefit of BAA is that it is a standardized auricular acupressure protocol for both acute and chronic pain, making it more conducive to widespread training and dissemination. However, our results demonstrate the need for more rigorous testing before general deployment.

There are few studies that have specifically tested the BAA protocol in post-operative populations. However, various auricular acupressure protocols have been used with mixed results in different post-operative populations (Zhong et al., 2019). Zhong and colleagues (2019) found auricular acupressure to be effective in decreasing post-operative analgesia and pain scores, but noted that all studies meeting their inclusion criteria (RCTs with or without blinding, adult population, within week of surgery, with or without sham arm) were from China with variations in acupoints used, time that pressure was applied to acupressure devices, and frequency of activation. Two studies have reported a significant decrease in analgesic use in patients undergoing TKA randomized to receive auricular acupressure within the first 48-72 hours of surgery (He et al. 2013; Chang 2012)delivered by trained acupuncturists/acupressure therapists. He and colleagues selected four acupoints on one ear (knee joint, Shen Men, [sympathesis], and subcortex) with activation 4 times a day for 3 minutes each totaling 48 minutes per day. Chang and colleagues (2012) reported using two points (subcortex and Shen Men) with patients applying pressure for 3 minutes per point 3 times a day for a total of 18 minutes per day. The total activation time per day was 15 minutes in our study. Thus, it is difficult to ascertain if the dosing of acupressure in our study was sufficient.

Westoff et al. (2021) in a RCT in women undergoing a medication abortion, used a similar modified battlefield auricular acupressure protocol as reported here. There were no differences in pain scores between those receiving modified battlefield auricular acupressure, acupuncture, or placebo. However, women randomized to the BAA arm, were instructed to apply pressure to the acupressure pads for 10 seconds each whenever they wished, total activation time was not reported. As in our study, clinicians without previous auricular acupressure experience were taught to apply the acupressure pads and the authors raised concern whether the brief training was sufficient.

As the opioid epidemic continues to plague the U.S., there is an urgent need to develop strategies that are effective, easily deployed, and acceptable to patients. We demonstrated that patients were highly satisfied with the treatment and even those not randomized to care, were interested in trying BAA, if offered. Exposure to BAA increased the likelihood that patients would be receptive to BAA for future post-operative pain control which suggests that exposure and experience is key to patient receptivity to novel methods. Our study also showed that patients in the treatment group remained engaged with the intervention, with over 80% activating the acupressure devices the last day of the study. It is worth noting that had three patients in the treatment group reach out after the study to request BAA for additional non study related procedures.

Limitations

Since this was a feasibility, as opposed to a mechanism of action trial, we did not employ a sham in this study. Device adherence may also have played a role in our ability to detect meaningful differences in pain or MME use. In a more controlled setting, any ear seeds lost would have been replaced to ensure participants received the full dose of the intervention. We also relied on patient reported adherence to the protocol. Patient reported adherence may not reflect actual use, so frequency and dose may play a role in effectiveness.

Others have raised concern that abbreviated training of non acupressure/acupuncture therapists in auricular acupressure may be one reason for lack of findings in some studies (Westoff et al., 2021). Although our nurses received training with a competency check-off by licensed and medical acupuncturists, the study was paused for several weeks for COVID and enrollment remained sluggish due to a decrease in surgery volumes. This interruption in the study and flow, may have diminished their proficiency.

Although we did not find a significant difference in worst pain scores and total opioid use through POD-4, this study may have been underpowered to detect a difference. There was less than a 10% difference in total MME consumption through POD-4. Interestingly, at POD-4, the difference in MME intake as well as pain scores began to widen (see Figure 3). It may be that the benefit of BAA is not seen in the initial post-operative but later in recovery and perhaps with a longer duration a greater difference would emerge. He and colleagues (2013), followed post TKA patients for 7 days, and found a significant difference in pain scores beginning on day 3 through day 7.

Conclusion

This study provides preliminary evidence that BAA may be a viable intervention that nurses can employ to help patients self-manage their post-operative pain. Determining the appropriate sham, the most effective dosing of the intervention in terms of time and frequency of activations, the timing of placement, and better elucidation of the mechanism of action are needed areas of research. In addition, attention needs to be paid to the quality of training and fidelity to the intervention over time.

Glossary

POD-4

post-operative day 4

PCA

patient controlled analgesia

BAA

battlefield auricular acupressure

ASA

American Society of Anesthesiologists

MME

morphine milligram equivalents

BFA

Battlefield auricular acupuncture

VHA

Veterans Health Administration