EMLA reduces acute and chronic pain after breast surgery for cancer

Gagan Mahajan, M.D.
Assistant Professor, UC Davis

Argyro Fassoulaki, Constantine Sarantopoulos, Aikaterini Melemeni, and Quinn Hogan Regional Anesthesia and Pain Medicine 25 (4); 2000

This study was designed to determine if perioperative application of EMLA (eutectic mixture of local anesthetics [25 mg lidocaine + 25 mg prilocaine per mL of emulsified water]) cream in the breast and axilla area reduces analgesic requirements, as well as the acute and chronic pain after breast surgery.

The pain that occurs in the immediate postoperative period after a modified radical mastectomy or lumpectomy with axillary lymph node dissection (alone or in combination with prophylactic chemotherapy and/or radiation therapy) is due to both the continuous firing of the nerves in the wound area and from direct surgical nerve injury. Neuropathic pain may also develop due to central mechanisms. Immediate post-surgical pain can interfere with early recovery. If inadequately treated, chronic pain may develop and cause impairments in activities of daily living. Chronic pain associated with breast surgery occurs in 65% of women aged 30 -­ 49 years and in 40% of women aged 50 - ­59 years.

46 female patients (<60 years="" of="" age="" were="" enrolled="" in="" a="" randomized="" double-blinded="" placebo-controlled="" study="" none="" had="" taken="" analgesics="" for="" three="" weeks="" preoperatively="" received="" opioids="" or="" other="" at="" induction="" intraoperatively="" emla="" placebo="" cream="" was="" applied="" different="" areas="" and="" covered="" with="" tegaderm:="" 5="" g="" on="" the="" sternal="" area="" five="" minutes="" before="" surgery="" supraclavicular="" immediately="" after="" extubation="" 10="" around="" axilla="" away="" from="" site="" incision="" same="" amount="" daily="" to="" locations="" four="" days="" postoperatively="" during="" first="" 24="" hours="" breakthrough="" pain="" treated="" propoxyphene="" 75="" mg="" paracetamol="" 600="" im="" every="" as="" needed="" second="" through="" fifth="" oral="" medications:="" 500="" 400="" codeine="" hydroxyzine="" 100="" tablets="" also="" given="" supplemental="" analgesia="" lt="" br="">
Pain at rest and with movement (90 degrees of arm abduction) was assessed at 0, 3, 6, 9, and 24 hours postoperatively and from the second through the fifth days postoperatively. Pain was self-rated using the visual analogue scale (VAS 1-10).

The patients were called three months postoperatively and asked to report if they had received chemotherapy or ration therapy; to describe the location, quality and intensity of their pain; and to report what analgesics, if any, they were taking. Pain intensity was self-rated using the visual intensity scale (VIS 0-3).

One patient was excluded from the study after developing a cutaneous allergy to either the EMLA cream or Tegaderm. 10/23 (43%) patients in the EMLA group and 7/22 (33%) in the control group had modified radical mastectomy with axillary node dissection. 13 (56%) and 16 (70%) patients in the EMLA group and 8 (36%) and 16 (73%) in the control group receive radiation therapy and chemotherapy, respectively.

The time to first analgesic requirement was longer in the EMLA (42 + 18) versus control (31 + 16) group [P = .04]. IM propoxyphene and paracetamol requirements between the two groups were statistically insignificant. However, from the second through fifth days the paracetamol and codeine oral consumption was less in the EMLA versus control group (P = .004 for paracetamol and P = .001 for codeine]. There was no statistical difference in terms of hydroxyzine consumption.

VAS scores at rest and with movement were not statistically significant between the two groups when recorded at 0, 3, 6, 9, and 24 hours and days 2, 3, 4, 5, and 6 postoperatively.

Chronic pain was reported in a lower percentage of patients in the EMLA group versus the placebo group: 22% and 68% with chest wall pain and 30% and 68% with axillary pain, respectively. 43% of the EMLA patients versus 91% of the control patient reported pain in >1 location. Analgesics were used during the first 3 months in 13% and 27% of the patients in the EMLA and control group, respectively. VIS was two times lower in the EMLA (0.7 + 0.9) versus control group (1.5 + 0.8). Numbness and loss of sensation in the upper arm was seen in 83% and 80% of the EMLA and control patients, respectively.

EMLA reduces postoperative analgesic requirements from postoperative days 1-6. With respect to chronic pain, the incidence and intensity was smaller in the EMLA group.

Interventional procedures, such as brachial plexus or paravertebral blocks, are also sometimes used for breast surgery. Neither has been shown to decrease the incidence of chronic post-mastectomy pain. Furthermore, they both have the disadvantage of complications, patient discomfort or technical difficulty. EMLA has the advantage of being non-invasive and allowing the patient to be relatively more functional during the immediate postoperative period.

1. The area of application and degree of skin integrity may influence the absorption of EMLA.
2. The depth of analgesia may be altered by regional cutaneous blood flow, dermal thickness, and possible uptake by nervous tissue.
3. It is unclear if application of EMLA to sites other than those tested would provide the same or different analgesia.
4. All of the patients could not be re-examined at three months postoperatively due to logistical reasons. Instead, phone interviews were conducted with all of the patients.

EMLA cream may be useful in breast surgery perioperatively, thus minimizing the immediate postoperative and chronic post-mastectomy pain.