ArticlePDF Available

Pulsed Electromagnetic Fields for Postsurgical Pain Management in Women Undergoing Cesarean Section A Randomized, Double-Blind, Placebo-controlled Trial

Pulsed Electromagnetic Fields for Postsurgical Pain
Management in Women Undergoing Cesarean Section
A Randomized, Double-Blind, Placebo-controlled Trial
Maryam Khooshideh, MD,*Seyedeh Sakineh Latifi Rostami, MD,*
Batool Ghorbani Yekta, MD,
and Ali Shahriari, MD
Objectives: To evaluate the efficacy of pulsed electromagnetic field
(PEMF) in relation to reducing postoperative pain, analgesic use,
and wound healing in patients undergoing Cesarean section
Methods: This randomized, double-blind, placebo-controlled trial
evaluated 72 women who underwent elective C-section. Thirty-six
patients were assigned to the active-PEMF and 36 to the sham-
PEMF groups. The participants were asked to report their pain
intensity on a Visual Analog Scale (VAS) at 2, 4, 6, 12, and 24
hours and 2, 4, and 7 days after surgery. The amount of analgesics
used was recorded. The surgical site was evaluated to assess the
wound-healing process on the seventh postoperative day.
Results: Postoperative pain VAS scores were significantly lower in
the active-PEMF group in all the measured periods within the early
and the late postoperative periods. Fewer women in the active-
PEMF group experienced severe postoperative pain within 24
hours postoperatively (36% vs. 72%, P= 0.002). Analgesic use
during the first 24 hours after C-section was 1.9-times lower in the
active-PEMF group (1.6 ± 0.7 vs. 3.1 ± 1.2, P< 0.001). The total
analgesic use during the seventh postoperative days was 2.1-times
lower in the active-PEMF group than in the sham group (1.7 ±0.7
vs. 3.7± 1.1, P< 0.001). Seven days postoperatively, patients in
the active-PEMF group had better wound healing with no exudate,
erythema, or edema (P= 0.02).
Conclusions: PEMF treatment after C-section decreases post-
surgical pain, analgesic use, and surgical wound exudate and edema
significantly, and is associated with a high level of patient
Key Words: electromagnetic therapy, healing, PEMF, post-
operative, wound
(Clin J Pain 2017;33:142–147)
Cesarean section (C-section) is a lifesaving surgical
procedure to deliver the baby. Most countries have
a C-section rate >15%, and approximately 18.5 million
C-sections are performed yearly throughout the world
according to the 2010 World Health Organization (WHO)
Postoperative pain management is an important issue
in clinical practice, especially in patients who undergo C-
section, because postoperative pain in these patients can
affect maternal and neonatal well-being adversely, and
might increase postsurgical complications.2–4 Postsurgical
pain can cause maternal immobility and further increase the
risk of thromboembolic events that has already increased
during pregnancy.2–4 Pain may also impair the mother’s
care for her neonate and may affect early mother-infant
interactions and effective breastfeeding adversely.2–4
Although different approaches have been described for
proper pain relief, these approaches are still inadequate and
unsatisfactory in many patients.2,3 In addition, due to lac-
tation, using systemic analgesics, especially opioids, which
are used commonly for post-C-section pain relief,3can
affect the mother and the infant negatively and increase
their morbidity.5,6 Therefore, finding a safe and effective
technique for post-C-section pain relief is an urgent need.
Pulsed electromagnetic field (PEMF) devices have
been cleared by the US Food and Drug Administration for
the relief of acute and chronic pain, the promotion of soft-
tissue healing, and the improvement of circulation.7–11
There is accumulating evidence that PEMF treatment can
have significant anti-inflammatory and tissue-healing
Recently, several studies have shown promising results
using PEMF in plastic and oral surgeries.9–14 Two studies
evaluated PEMF treatment for the postsurgical pain con-
trol in breast surgeries; in these studies, PEMF treatment
reduced the pain and the use of analgesics significantly in
the postsurgical period.10,11 Improvement in soft-tissue
healing and pain management were also reported in
another study that used PEMF treatment after oral sur-
gery.9Several pathways have been proposed for the anti-
inflammatory and analgesic effects of PEMF treatment,
including the effects of PEMF signals on increasing anti-
inflammatory cytokines, endogenous analgesic agents, and
endogenous opioid precursor proteins, and decreasing
proinflammatory cytokines and endogenous hyperalgesic
Given the promising results of PEMF treatment in
plastic and oral surgeries and the growing evidence of
safety, pain-relieving, anti-inflammatory, and tissue-healing
effects of PEMF devices, we postulate that these devices
Received for publication October 15, 2015; revised March 30,
2016; accepted March 7, 2016.
From the Departments of *Obstetrics and Gynecology, Arash Wom-
en’s Hospital; yAnesthesiology, Roozbeh Hospital; wMaternal,
Fetal and Neonatal Research Center, Tehran University of Medical
Sciences; and zDepartment of Physiology, Applied Physiology
Research Center, Tehran Medical Sciences Branch, Islamic Azad
University, Tehran, Iran.
Supported by the Research Deputy of the Tehran University of Med-
ical Sciences (Grant Number: 93D-940-130), Tehran, Iran. The
authors declare no conflict of interest.
Reprints: Mahdi Sheikh, MD, PhD, Maternal, Fetal and Neonatal
Research Center, Vali-asr Hospital, Imam Khomeini Hospital
Complexes, Keshavarz Blvd, Tehran 1419733141, Iran (e-mail:
Copyright r2016 Wolters Kluwer Health, Inc. All rights reserved.
DOI: 10.1097/AJP.0000000000000376
142 | Clin J Pain Volume 33, Number 2, February 2017
Copyright r2017 Wolters Kluwer Health, Inc. All rights reserved.
could also be used in other kinds of surgeries, especially in
laparotomy and obstetrics surgeries, which are associated
with significant postoperative pain and opioid use. On
searching the literature, we could not find studies evaluating
the effect of PEMF treatment in surgeries involving deep
organs. It is still unknown whether PEMF treatment can
provide an acceptable pain relief and tissue healing in these
kinds of surgeries.
In view of this lack of information, we conducted this
study to evaluate the efficacy of PEMF treatment in
reducing postoperative pain and analgesic use in patients
undergoing a C-section. We also tried to evaluate the effect
of PEMF treatment on wound healing, return to daily liv-
ing activities, and participant satisfaction.
Study Population and Study Design
This prospective, randomized, double-blinded, pla-
cebo-controlled trial was conducted on 72 pregnant women
who were admitted to Arash Women’s Hospital (a tertiary
referral center), of the Tehran University of Medical Sci-
ences, Tehran, Iran, for elective C-section delivery from
August 2014 through December 2014. Women were con-
sidered eligible if they met the following inclusion criteria:
20 to 35 years of age, singleton uncomplicated pregnancy, a
gestational age of 37 to 42 weeks, and not having a history
of >1 C-sections. Exclusion criteria were: having any
underlying medical disease, a history of any abdominal
surgery other than C-section, a history of any drug or
opium dependency, and refusing to give an informed con-
sent to participate in the study.
Randomization was performed before the surgery. A
computerized random number generator was used for
sequence generation, which was carried out by M.S. Simple
randomization with a 1:1 allocation ratio was used in this
study. We used consecutive opaque envelops for allocation
concealment, which was performed by S.S.L.R. The
envelops were opaque when held to the light, and were
opened sequentially only after the participant’s name and
other details were written on the appropriate envelop. The
implementation of assignments was carried out by M.K.
This study was double-blinded, with M.S. performing the
blinding. Health care providers, participants, and data
collectors were all blinded to the PEMF and sham-PEMF
groups until the end of the study.
The Intervention, Data, and Specimen Collection
After explaining the procedure and obtaining a written
informed consent from the participants, a standardized
questionnaire was completed for the mothers who enrolled
in the study through interviews and medical records. The
questionnaire contained demographic, medical, gyneco-
logical, obstetrical, and social history, as well as vital signs
obtained through physical examinations and the gestational
age that was calculated on the basis of ultrasound imaging.
The participants were allocated randomly into 2 groups: 36
were assigned to the intervention (PEMF treated) group
and 36 were allocated to the placebo (sham-PEMF treated)
group (Fig. 1).
A Visual Analog Scale (VAS) was used to determine
the pain intensity; VAS is a continuous scale comprised of a
horizontal line 100 mm in length. The scale ranges from 0
(no pain) to 100 (worst imaginable pain). The following
cutoff points on the pain VAS were used: no pain (0 to
4 mm), mild pain (5 to 44 mm), moderate pain (45 to
74 mm), and severe pain (75 to 100 mm). Patients were
educated on how to use and interpret the pain VAS; they
were also asked to place a cross-line on the unmarked
horizontal scale at the required times.
All participants underwent spinal anesthesia with
12.5 mg bupivacaine. Immediately after the C-section,
either an active-PEMF device (RecoveryRx; BioElectronics
Corp.) or a sham-PEMF device (an exactly similar device
without any electromagnetic activity that was made by the
same company) was placed on the surgical wound dressing
continuously for 7 days (Fig. 2). The PEMF devices used in
this study consisted of an elliptical coil that was 12 cm in
size and a radiofrequency energy generator powered by a
battery that had an emission frequency of 27.1 MHz, a
pulse rate of 1000 pulses per second, a 100-ms pulse dura-
tion, and a peak spatial power density of 75 mW/cm
. The
circuitry consisted of low-voltage (3 V) digital or analog
electronics controlling all of the timing functions to pro-
duce the therapeutic radiofrequency field with the antenna’s
field directly over the site to be treated. The devices applied
to patients in the placebo group were switched on in the
same way as the active devices, but without producing an
electromagnetic field.
Participants were asked to report their pain intensity
on the basis of the VAS, and the pain intensity was eval-
uated at 2, 4, 6, 12, and 24 hours after surgery. After dis-
charge, participants were asked to record their pain
intensity on the second, the fourth, and the seventh post-
operative days. The requirement for analgesics during the
hospital admission and the amount of analgesics used were
recorded. In our study, diclofenac 100 mg suppositories
were used as the postoperative analgesic. The surgical site
was evaluated for factors that could delay the wound-
healing process including infection, erythema, hematoma,
edema, and wound exudate on the seventh postoperative
day. For ethical reasons, on discharge, analgesics were
recommended for all patients (diclofenac 100 mg supposi-
tories, once a day) on an as-needed basis. Patients could
choose to discontinue or use none if they had no symptoms.
Participants were asked to record the amount of analgesics
used from the discharge day till the seventh postoperative
day. The duration needed to return to daily living activities
as reported by the mother and the patient satisfaction (not
satisfied, moderately satisfied, highly satisfied) from the
treatment received were also recorded at the end of the
The primary outcome of our study was the post-
operative pain intensity as reported by the pain VAS during
the first 24 hours and 1 week postoperatively. Secondary
outcomes were the amount of analgesic use during the
postoperative period, the presence of edema, erythema,
hematoma, and exudate from the surgical wound on the
seventh postoperative day that could impair the wound-
healing process, the duration of return to daily living
activities, and overall participant satisfaction.
This study was approved by the Research Deputy and
the Ethics Committee of Tehran University of Medical
Sciences on July 17, 2014 (approval number: 93/D/940/130)
and is registered at the Iranian Registry of Clinical
Trials (, which is a Primary Registry in
the WHO Registry Network (registration number =
IRCT2014070711020N3). The authors confirm that all
ongoing and related trials for this intervention are
Clin J Pain Volume 33, Number 2, February 2017 PEMF and Postsurgical Pain
Copyright r2016 Wolters Kluwer Health, Inc. All rights reserved. |143
Copyright r2017 Wolters Kluwer Health, Inc. All rights reserved.
Although the study was submitted to http://www.irct.
ir before the expected recruitment start date, the approval
process took a long time and the date of confirming the
registration passed the submitted starting date; therefore,
the registration timing appeared as registration while
recruiting. However, officially, recruiting the patients was
started after the registration approval on August 05, 2014
and was ended on the December 10, 2014, 1 month after the
expected end date.
Another change that was made to the registered pro-
tocol was that in the original protocol the time point was set
at 10 days after C-section; however, because significant
postsurgical pain usually does not last for >1 week, and
also because the first 7 days after surgery are the crucial
period for wound healing, the time point was changed to 7
Statistical Analysis
The sample size was calculated for a power of 80%,
a= 0.05, b= 20%, and a standard effect size of 0.85. All
statistical analyses were performed using SPSS statistical
software (PASW version 18.0.0; SPSS Inc., Chicago, IL).
Data were displayed using mean, SD, and percentage.
Mean comparisons between 2 groups and variables were
performed using the ttest for independent samples. Pearson
correlation coefficient, w
analysis, Fisher exact test,
repeated measures analysis of variance (ANOVA), and the
Logistic Regression Model were also used. The level of
statistical significance was set at P-value <0.05.
FIGURE 2. The PEMF device attached to the surgical wound
FIGURE 1. The flow diagram of the study showing patients’ randomization.
Khooshideh et al Clin J Pain Volume 33, Number 2, February 2017
144 | Copyright r2016 Wolters Kluwer Health, Inc. All rights reserved.
Copyright r2017 Wolters Kluwer Health, Inc. All rights reserved.
Descriptive Statistics
This study included 72 women with a singleton
uncomplicated pregnancy with a gestational age >37 weeks
who were admitted for elective C-section. Thirty-six women
were assigned randomly in the intervention group to receive
active-PEMF therapy and 36 to the placebo group to
receive the sham-PEMF therapy, for 7 days post-
operatively. On enrollment, the mean ± SD of the partic-
ipants’ age was 26.1 ± 2.6 years, the gestational age was
39.2 ± 1.5 weeks, the body mass index before pregnancy
was 24.2 ± 3.9, and the body mass index upon admission
was 32.1 ± 2.7. About 36 participants (50%) had a pre-
vious history of C-section. The ttest for independent
samples and the w
analysis showed that there were no
significant differences in the demographics between the 2
study groups (Table 1).
The Effect of PEMF Therapy on Postoperative
Pain and Analgesic Use
Repeated measures ANOVA and the independent
samples ttest demonstrated that the postoperative pain
VAS scores were significantly lower in the active-PEMF
group than in the sham-PEMF group in all the measured
periods (Table 2 and Fig. 3). The w
analysis showed that
fewer women in the active-PEMF group experienced severe
postoperative pain (VAS score of 75 to 100 mm) within 24
hours after the C-section compared with the sham-PEMF
group (36% vs. 72%, P= 0.002).
According to the independent samples ttest, analgesic
use (mean suppository counts) during the first 24 hours
after C-section was 1.9-times lower in the active-PEMF
group than in the sham group (1.6 ± 0.7 vs. 3.1 ± 1.2,
P< 0.001). Total analgesic use during 7 postoperative days
was 2.1-times lower in the active-PEMF group compared
with the sham group (1.7 ± 0.7 vs. 3.7 ± 1.1, P< 0.001)
(Table 3 and Fig. 4).
The Effect of PEMF Therapy on Surgical-Site
Inflammation, Patient Satisfaction, and Return
to Daily Activities
We used the w
analysis and the Fisher exact test when
appropriate to compare secondary outcomes between the 2
study groups. Seven days after the C-section, mothers in the
sham-PEMF group had significantly higher rates of wound
exudate (13% vs. 0%, P= 0.02) and edema (11% vs. 0%,
P= 0.04) in the surgical site compared with the active-
PEMF group. No infection or erythema was observed in
any of the groups (Table 3). The satisfaction level was
significantly higher in the active-PEMF group (P= 0.001):
in the active-PEMF-treated group, 50% of the patients
reported a high and 50% had a moderate satisfaction level
with the treatment received, whereas in the sham group,
25% reported high and 44% had moderate satisfaction
levels, and 30% were not satisfied with the treatment
received (Table 3). Using the independent samples ttest, no
statistically significant differences were observed in the time
to return to daily activities between the 2 groups (the active-
PEMF group: 3.4 ± 0.7 d; the sham-PEMF group:
3.6 d ± 1.3, P= 0.58) (Table 3).
This was the first study to evaluate the applicability of
PEMF devices in surgeries involving deep organs and lap-
arotomy. PEMF therapy reduced postsurgical pain and the
use of analgesics effectively in the both the immediate and
the late postsurgical periods in women who underwent C-
section, and reproduced essential findings in studies with
other surgical procedures. In the studies of Heden and
Pilla11 and Rohde et al,10 PEMF treatment provided good
pain control and reduced narcotic use postoperatively in
breast augmentation and reduction surgeries. In addition,
in the Stocchero et al9study, PEMF treatment reduced the
pain after mandibular third-molar extraction significantly.
Several mechanisms involving inflammatory mediators
might contribute to the analgesic effects of PEMF treat-
ment. Studies have shown that PEMF signals increase the
anti-inflammatory cytokine interleukin (IL)-10 and
decrease the proinflammatory cytokine IL-1b,10,15 which is
a potent hyperalgesic agent and a stimulator of nociceptors
through direct and indirect pathways.16,17 Animal studies
suggest that IL-1bmight be a signaling molecule that can
excite nociceptive fibers in as little as 1 minute in sensory
transmission, and IL-1breceptors were found in many
sensory neurons.16–19 IL-1balso modulates neuronal
excitability through its effect on neuronal receptors such as
sodium channels, GABA receptors, NMDA receptors, and
through its effect on the release or the activation of noci-
ceptive molecules such as prostaglandins, IL-6, and sub-
TABLE 1. Comparison of Demographics Between the
Intervention (Active-PEMF) and the Placebo (Sham-PEMF)
PEMF Group
(N = 36)
Placebo Group
(N = 36) P
Participants age (y)
(mean ± SD)
26.4 ± 2.3 25.9 ± 2.9 0.43 (NS)
Gestational age (wk)
(mean ± SD)
39.4 ± 1.6 39.1 ± 1.4 0.8 (NS)
BMI before
(mean ± SD)
23.8 ± 3.4 24.5 ± 4.4 0.46 (NS)
BMI upon admission
(mean ± SD)
32.3 ± 2.8 31.8 ± 2.6 0.52 (NS)
History of previous
C/S (n [%])
18 (50) 18 (50) 1 (NS)
BMI indicates body mass index; C/S, Cesarean section; NS, non-
significant; PEMF, pulsed electromagnetic field.
TABLE 2. Comparison of Pain VAS Scores and Analgesic Use
Between the Active-PEMF and the Sham-PEMF Groups in the
Measured Times
Mean ± SD of Pain VAS Scores
Group P
2 h 53 ± 18 63 ± 16 0.01
4 h 41 ± 13 59 ± 8 < 0.001
6 h 37 ± 13 51 ± 8 < 0.001
12 h 30 ± 5 38 ± 10 < 0.001
24 h 23 ± 4 36 ± 12 < 0.001
2 d 18 ± 10 26 ± 4 < 0.001
4 d 6 ± 4 16 ± 4 < 0.001
7 d 0.8 ± 2 3 ± 4 0.01
PEMF indicates pulsed electromagnetic field; VAS, Visual Analog Scale.
Clin J Pain Volume 33, Number 2, February 2017 PEMF and Postsurgical Pain
Copyright r2016 Wolters Kluwer Health, Inc. All rights reserved. |145
Copyright r2017 Wolters Kluwer Health, Inc. All rights reserved.
PEMF may also produce analgesic effects by affecting
nitric oxide (NO) synthesis; NO exhibits analgesic effects in
the periphery in early stages of inflammation, and pain
intensity has been shown to correlate negatively with NO
levels.22 PEMF increases NO synthesis through a cascade
that involves calcium, calmodulin, and cGMP produc-
tion.23,24 Another proposed mechanism is the effect of
PEMF on endogenous opioids. PEMF was shown to
increase endogenous opioid precursor proteins including
proenkephalin, proopiomelanocortin, and prodynorphin.15
In the study of Ventura et al,25 direct exposure of isolated
myocyte nuclei to PEMF enhanced prodynorphin gene
transcription markedly.
In our study, PEMF was associated with a better
wound-healing response at 7 days postoperatively, without
any exudate, edema, or erythema at the incision site. Other
studies that used PEMF in oral and plastic surgeries also
reported that PEMF therapy accelerated wound healing
and tissue repair.9–11 PEMF signals modulate Ca
ing to calmodulin and calmodulin-dependent enzymes and
NO production.24,26 Evidence from animal and human
studies indicate that NO plays a key role in wound repair,
which is attributable to its functional influences on angio-
genesis, inflammation, cell proliferation, and matrix depo-
sition and remodeling.27 Moffett and colleagues evaluated
the effect of PEMF on cultured human keratinocyte and
fibroblast cells; they found that mRNA levels of many
factors that are involved in tissue repair and remodeling
were upregulated after PEMF exposure. PEMF treatment
resulted in the increased expression of integrins and cell
surface receptors that interact with components of the
extracellular matrix.28 During wound healing, integrins
play important roles in reepithelialization, angiogenesis,
and wound contraction. Transcript levels of multiple
cyclins and DNA replication factors that regulate cell
division were also upregulated after PEMF treatment in
both cell types.28
In this study, postoperative PEMF therapy was safe
and easily applicable, and the mothers were highly satisfied
with using this device in the postsurgical period. The
FIGURE 3. Mean pain Visual Analog Scale (VAS) scores between
the pulsed electromagnetic field (PEMF)-treated (thick line) and
the placebo-treated (thin line) groups during the 7 postoperative
TABLE 3. Comparison of the Outcomes Between the Active-
PEMF and Sham-PEMF Groups
(N = 36)
(N = 36) P
Experiencing severe pain
within 24 h PO (n [%])
13 (36) 26 (72) 0.002*
Analgesic use within 24 h PO
(mean ± SD [sum of
suppository count])w
1.6 ± 0.7
3.1 ± 1.2
< 0.001*
Analgesic use within 7 d PO
(mean ± SD [sum of
suppository count])w
1.7 ± 0.7
3.7 ± 1.1
< 0.001*
Duration to return to daily
activities (mean ± SD) (d)
3.4 ± 0.7 3.6 ± 1.3 0.58
Satisfaction levels (n [%]) 0.001*
High 18 (50) 9 (25)
Moderate 18 (50) 16 (44)
Low 0 11 (30)
Surgical wound infection
(n [%])
Surgical wound exudate at
10 d PO (n [%])
0 5 (13) 0.02*
Surgical wound edema at
10 d PO (n [%])
0 4 (11) 0.04*
*Statistically significant P-value (< 0.05).
wDiclofenac 100 mg suppositories.
PEMF indicates pulsed electromagnetic field; PO, postoperation.
FIGURE 4. The number of Diclofenac suppositories used within
24 hours and 7 days postoperatively in the treatment versus the
placebo group.
Khooshideh et al Clin J Pain Volume 33, Number 2, February 2017
146 | Copyright r2016 Wolters Kluwer Health, Inc. All rights reserved.
Copyright r2017 Wolters Kluwer Health, Inc. All rights reserved.
available literature supports the safety of PEMF devices in
long-term applications.8These promising results show that
PEMF therapy can be used as an effective and safe
modality for postoperative pain management, with positive
effects on wound healing that is associated with high
maternal satisfaction in the postoperative period. In addi-
tion, by decreasing maternal requirement for systemic
analgesics and opioids during the postoperative period, and
subsequently decreasing neonatal exposure to these drugs,
PEMF therapy could also have potential benefits to the
neonates. However, effects of PEMF therapy on lactation,
neonatal wellbeing, and mother-infant interaction requires
investigation in future studies.
1. Gibbons L, Beliza
´n JM, Lauer JA, et al. The global numbers
and costs of additionally needed and unnecessary caesarean
sections performed per year: overuse as a barrier to universal
coverage. World Health Rep. 2010. Background Paper, No 30.
2. Snell P, Hicks C. An exploratory study in the UK of the
effectiveness of three different pain management regimens for
post-caesarean section women. Midwifery. 2006;22:249–261.
3. Shahraki AD, Jabalameli M, Ghaedi S. Pain relief after
cesarean section: oral methadone vs. intramuscular pethidine.
J Res Med Sci. 2012;17:143–147.
4. Gadsden J, Hart S, Santos AC. Post-cesarean delivery
analgesia. Anesth Analg. 2005;101(suppl):S62–S69.
5. Miaskowski C. A review of the incidence, causes, consequen-
ces, and management of gastrointestinal effects associated with
postoperative opioid administration. J Perianesth Nurs.
6. Spigset O, Hagg S. Analgesics and breast-feeding: safety
considerations. Paediatr Drugs. 2000;2:223–238.
7. Bassett CA. Beneficial effects of electromagnetic fields. J Cell
Biochem. 1993;51:387–393.
8. Efthimiou P, Kukar M. Complementary and alternative
medicine use in rheumatoid arthritis: proposed mechanism of
action and efficacy of commonly used modalities. Rheumatol
Int. 2010;30:571–586.
9. Stocchero M, Gobbato L, De Biagi M, et al. Pulsed electro-
magnetic fields for postoperative pain: a randomized con-
trolled clinical trial in patients undergoing mandibular third
molar extraction. Oral Surg Oral Med Oral Pathol Oral Radiol.
10. Rohde C, Chiang A, Adipoju O, et al. Effects of pulsed
electromagnetic fields on interleukin-1 beta and postoperative
pain: a double-blind, placebo-controlled, pilot study in breast
reduction patients. Plast Reconstr Surg. 2010;125:1620–1629.
11. Heden P, Pilla AA. Effects of pulsed electromagnetic fields on
postoperative pain: a double-blind randomized pilot study in
breast augmentation patients. Aesthetic Plast Surg. 2008;32:
12. Harper WL, Schmidt WK, Kubat NJ, et al. An open-label
pilot study of pulsed electromagnetic field therapy in the
treatment of failed back surgery syndrome pain. Int Med Case
Rep J. 2015;8:13–22.
13. Strauch B, Herman C, Dabb R, et al. Evidence-based use of
pulsed electromagnetic field therapy in clinical plastic surgery.
Aesthet Surg J. 2009;29:135–143.
14. Kinney BM. Pulsed electromagnetic field therapy in plastic
surgery. Aesthet Surg J. 2005;25:87–91.
15. Moffett J, Fray LM, Kubat NJ. Activation of endogenous
opioid gene expression in human keratinocytes and fibroblasts
by pulsed radiofrequency energy fields. J Pain Res. 2012;5:
16. Fukuoka H, Kawatani M, Hisamitsu T, et al. Cutaneous
hyperalgesia induced by peripheral injection of interleukin-1
beta in the rat. Brain Res. 1994;657:133–140.
17. Ren K, Torres R. Role of interleukin-1beta during pain and
inflammation. Brain Res Rev. 2009;60:57–64.
18. Copray JC, Mantingh I, Brouwer N, et al. Expression of
interleukin-1 beta in rat dorsal root ganglia. J Neuroimmunol.
19. Obreja O, Rathee PK, Lips KS, et al. IL-1 beta potentiates
heat-activated currents in rat sensory neurons: involvement of
IL-1RI, tyrosine kinase, and protein kinase C. FASEB J.
20. Schafers M, Sorkin L. Effect of cytokines on neuronal
excitability. Neurosci Lett. 2008;437:188–193.
21. Inoue A, Ikoma K, Morioka N, et al. Interleukin-1beta
induces substance P release from primary afferent neurons
through the cyclooxygenase-2 system. J Neurochem. 1999;73:
22. Hamza M, Wang XM, Wu T, et al. Nitric oxide is negatively
correlated to pain during acute inflammation. Mol Pain.
23. Fitzsimmons RJ, Gordon SL, Kronberg J, et al. A pulsing
electric field (PEF) increases human chondrocyte proliferation
through a transduction pathway involving nitric oxide signal-
ing. J Orthop Res. 2008;26:854–859.
24. Pilla AA. Electromagnetic fields instantaneously modulate
nitric oxide signaling in challenged biological systems. Biochem
Biophys Res Commun. 2012;426:330–333.
25. Ventura C, Maioli M, Pintus G, et al. Elf-pulsed magnetic
fields modulate opioid peptide gene expression in myocardial
cells. Cardiovasc Res. 2000;45:1054–1064.
26. Pilla A, Fitzsimmons R, Muehsam D, et al. Electromagnetic
fields as first messenger in biological signaling: application to
calmodulin-dependent signaling in tissue repair. Biochim
Biophys Acta. 2011;1810:1236–1245.
27. Luo JD, Chen AF. Nitric oxide: a newly discovered function
on wound healing. Acta Pharmacol Sin. 2005;26:259–264.
28. Moffett J, Kubat NJ, Griffin NE, et al. Pulsed radio frequency
energy field treatment of cells in culture: increased expression
of genes involved in angiogenesis and tissue remodeling
during wound healing. J Diabetic Foot Complications. 2011;3:
Clin J Pain Volume 33, Number 2, February 2017 PEMF and Postsurgical Pain
Copyright r2016 Wolters Kluwer Health, Inc. All rights reserved. |147
Copyright r2017 Wolters Kluwer Health, Inc. All rights reserved.
Full-text available
Background The value of pulsed electromagnetic field (PEMF) in postoperative pain management, due to the inconsistent findings so far, remains unclear. We extended the evaluation of PEMF on postoperative pain and intravenous (IV) analgesic use to a group of post-appendicectomy Asian patients. Methods This is a double-blinded, randomized trial. Adults with a clinical diagnosis of acute appendicitis were enrolled. Patients were allocated randomly to receive an active-PEMF device or an inactive device after the surgery in addition to the standard postoperative pain management. The primary outcome measure was the 12-h cumulative postoperative pain intensity measured at four different time points using the visual analogue scale. The secondary outcome measure was the total amount of IV fentanyl used (in mg) via PCA over the first 12 postoperative hours. The primary analysis in this trial compared the two study groups for the reported cumulative pain score (both at rest and on movement) and the cumulative amount of IV fentanyl uses over the first 12 postoperative hours using the Wilcoxon rank sum test. Analyses were performed based on the intention-to-treat principal. Multiple imputation was used to handle the missing data assuming that the data were missing at random. Findings One hundred eighteen subjects were randomized; 58 were allocated to the active-PEMF group and 60 to the inactive control group. Pooled mean pain score of both intervention groups by time point declined in a similar fashion over the course of 12 postoperative hours. The 12-h cumulative postoperative pain score at rest and on movement did not differ significantly after the procedure. (W = 1832.5 ~ 1933.0, p-value 0.6192 ~ 0.2985 for resting pain score comparison; W = 1737.0 ~ 1804.5, p-value 0.9892 ~ 0.7296 for movement pain score comparison). For the secondary outcome measure of 12-h total fentanyl use, a comparison between the PEMF vs. placebo arm also revealed no statistically significant difference across all the 20 imputed datasets (W = 1676.5 ~ 1859.0, p-value 0.7344 ~ 0.5234). Discussion PEMF was not superior to placebo as an adjunct pain management for up to 12 h post-appendicectomy. Previously reported effect of PEMF on postoperative pain intensity and analgesia uses in similar surgical settings cannot be verified. Trial registration National Medical Research Register Malaysia (NMRR-15–670-25,805) and Thai Clinical Trials Registry (retrospectively registered on November 01, 2019, Study ID—TCTR20191102002).
Full-text available
Introducción La cesárea es un procedimiento quirúrgico que puede pre-venir la mortalidad materna y neonatal cuando se utiliza por razones médicas indicadas. La Organización Mundial de la Salud (OMS) concluyó que la tasa de cesárea no de-bía ser superior al 10-15%, ya que tasas superiores contri-buyen a un aumento en la morbilidad materna y del neo-nato. Recientemente, sin embargo, la OMS aconsejó realizar una cesárea a toda mujer que lo precise, y no tan-to por ajustarse a alcanzar una tasa de cesárea específica 1. La tasa media de cesáreas en Europa es del 27% (en Es-paña se sitúa en el 24,8%) 2. Dada la elevada prevalencia de cesáreas, es relevante explorar qué cuidados se propor-cionan a la herida quirúrgica tras una cesárea, ya que una alteración en la cicatrización conlleva efectos secundarios indeseables locales que se asocian a restricción de movi-mientos, secuelas estéticas y, en ocasiones, psicológicas 3. El objetivo de este artículo es actualizar los conocimien-tos del cuidado de la herida quirúrgica tras una cesárea. Metodología La pregunta de intervención se describió en forma de PICO para diseñar la estrategia de búsqueda bibliográfica: ¿Qué cuidados postoperatorios en la herida quirúrgica son efec-tivos tras una cesárea? Se realizó una búsqueda bibliográfica en las bases de da-tos Cochrane Library, Cinahl, Medline, Cuiden y Cuidat-ge. Las palabras clave usadas fueron: caesarean, c-section, wound closure, cosmetic outcomes, scar, dressing y healing. Se limitó la búsqueda por idioma (inglés y castella-no) y por tiempo (desde 2010 hasta 2019). Se examinaron 26 referencias bibliográficas, de las cua-les 20 se ajustaron a la pregunta (1 revisión sistemática, 8 ensayos clínicos, 1 estudio cualitativo, 1 caso clínico, 8 es-tudios observacionales y 1 artículo especial). Cuidados tras la cesárea En la tabla se pueden ver los procesos y técnicas de cura-ción de la herida.
Trauma, infection, cancer and congenital diseases can lead to bone defects. The combination of 3D printing with biomaterials is of great significance in the treatment of bone defects. In addition, pulse electromagnetic fields (PEMFs) can promote bone regeneration. The main purpose of this study was to evaluate the effects of 3D-printed scaffolds using β-tricalcium phosphate (β-TCP) as the raw material combined with a PEMF on the proliferation and differentiation of rat adipose stem cells (rADSCs) and on the repair of critical defects of the rat skull. Cell Counting Kit-8 (CCK-8) was performed to assess the proliferation of rADSCs. Alkaline phosphatase (ALP) activity, ALP staining and the detection of osteogenic-related gene expression was performed to assess the differentiation of rADSCs. Micro computed tomography (mCT) and hematoxylin-eosin (HE) staining were used to assess the repair of rat skull defects. The results showed that the combination of the scaffold and PEMF could significantly promote the proliferation and differentiation of rADSCs and the repair of a critical defect in the rat skull. Therefore, the combination of β-TCP and PEMF with 3D printing technology can provide better treatment of clinical bone defect patients.
Full-text available
Persistent pain following back surgery remains a major treatment challenge. The primary objective of this open-label exploratory study was to investigate the analgesic effectiveness of pulsed electromagnetic field therapy administered twice daily over a 45-day period in 34 subjects (68% female) with persistent or recurrent pain following back surgery. A secondary goal was to guide the design of future randomized controlled trials that could target responsive subpopulations. All predefined primary and secondary outcomes, including change in pain intensity (PI), physical function (Oswestry Disability Index), analgesic consumption, and overall well-being (Patient Global Impression of Change), are reported. A responder analysis (≥30% reduction in PI versus baseline) was added as a post hoc evaluation. Safety outcomes, as well as results of a cost-avoidance survey, are also summarized. Of the 30 per-protocol subjects who completed the study, 33% reported a clinically meaningful (≥30%) reduction in PI. A higher response rate (60%) was reported for subjects who had undergone discectomy prior to the trial compared to subjects who had undergone other types of surgical interventions (decompression or fusion) without discectomy. Improvements in PI were paralleled by improvements in secondary outcomes. Relative to baseline, responders reported an average 44% and 55% reduction in back PI and leg PI (respectively), and an average 13% improvement in Oswestry Disability Index scores. In the per-protocol population, 50% of responders and 12% of nonresponders reported less analgesia consumption at the end of treatment versus baseline. Sixty-seven percent of per-protocol responders and 0% of nonresponders reported clinically meaningful improvement in overall well-being on the Patient Global Impression of Change scale.
Full-text available
Pulsed radiofrequency energy (PRFE) fields are being used increasingly for the treatment of pain arising from dermal trauma. However, despite their increased use, little is known about the biological and molecular mechanism(s) responsible for PRFE-mediated analgesia. In general, current therapeutics used for analgesia target either endogenous factors involved in inflammation, or act on endogenous opioid pathways. Using cultured human dermal fibroblasts (HDF) and human epidermal keratinocytes (HEK), we investigated the effect of PRFE treatment on factors, which are involved in modulating peripheral analgesia in vivo. We found that PRFE treatment did not inhibit cyclooxygenase enzyme activity, but instead had a positive effect on levels of endogenous opioid precursor mRNA (proenkephalin, pro-opiomelanocortin, prodynorphin) and corresponding opioid peptide. In HEK cells, increases in opioid mRNA were dependent, at least in part, on endothelin-1. In HDF cells, additional pathways also appear to be involved. PRFE treatment was also followed by changes in endogenous expression of several cytokines, including increased levels of interleukin-10 mRNA and decreased levels of interleukin-1β mRNA in both cell types. These findings provide a new insight into the molecular mechanism underlying PRFE-mediated analgesia reported in the clinical setting.
Full-text available
The role that nitric oxide (NO) plays in modulating pain in the periphery is unclear. We show here, the results of two independent clinical studies (microdialysis and gene expression studies) and a pilot dose finding study (glyceryl trinitrate study), to study the role of NO in the early phase of acute inflammatory pain following oral surgery. The effect of ketorolac on NO production and nitric oxide synthase (NOS) gene expression was also studied. Microdialysis samples showed significantly higher levels of NO at the first 100 min compared to the last 80 minutes in the placebo treated group. In the ketorolac group, on the other hand, NO levels gradually decreased over the first 60 min but were similar to placebo over the later 100-180 min, with no significant change in NO level over time. The levels of NO were negatively correlated to pain intensity scores. Local infusion of the NO donor glyceryl trinitrate at the site of surgery, showed a small analgesic effect that did not reach statistical significance in the sample size used. While the gene expression of iNOS and eNOS were not up-regulated, 3 hours after surgery, nNOS was downregulated in both treatment groups and eNOS gene expression was significantly lower in the ketorolac group compared to the placebo group. Further, there was a positive correlation between the change in gene expression of nNOS and eNOS in the placebo group but not in the ketorolac group. We suggest that at this early stage of inflammatory pain in man, NO is analgesic in the periphery. Further, ketorolac down-regulates eNOS gene expression.
Full-text available
Surgeons seek new methods of pain control to reduce side effects and speed postoperative recovery. Pulsed electromagnetic fields are effective for bone and wound repair and pain and edema reduction. This study examined whether the effect of pulsed electromagnetic fields on postoperative pain was associated with differences in levels of cytokines and angiogenic factors in the wound bed. In this double-blind, placebo-controlled, randomized study, 24 patients, undergoing breast reduction for symptomatic macromastia received pulsed electromagnetic field therapy configured to modulate the calmodulin-dependent nitric oxide signaling pathway. Pain levels were measured by a visual analogue scale, and narcotic use was recorded. Wound exudates were analyzed for interleukin (IL)-1 beta, tumor necrosis factor-alpha, vascular endothelial growth factor, and fibroblast growth factor-2. Pulsed electromagnetic fields produced a 57 percent decrease in mean pain scores at 1 hour (p < 0.01) and a 300 percent decrease at 5 hours (p < 0.001), persisting to 48 hours postoperatively in the active versus the control group, along with a concomitant 2.2-fold reduction in narcotic use in active patients (p = 0.002). Mean IL-1 beta concentration in the wound exudates of treated patients was 275 percent lower (p < 0.001). There were no significant differences found for tumor necrosis factor-alpha, vascular endothelial growth factor, or fibroblast growth factor-2 concentrations. Pulsed electromagnetic field therapy significantly reduced postoperative pain and narcotic use in the immediate postoperative period. The reduction of IL-1 beta in the wound exudate supports a mechanism that may involve manipulation of the dynamics of endogenous IL-1 beta in the wound bed by means of a pulsed electromagnetic field effect on nitric oxide signaling, which could impact the speed and quality of wound repair.
Full-text available
Complementary and alternative medicine (CAM) has become popular in patients with rheumatoid arthritis (RA) worldwide. The objective of this study is to systematically review the proposed mechanisms of action and currently available evidence supporting the efficacy of CAM modalities in relieving signs and symptoms of RA. The prevalence of CAM usage by RA patients is anywhere from 28% to 90%. Many published studies on CAM are based on animal models of RA and there is often insufficient evidence for the efficacy of CAM modalities in RA. The existing evidence suggests that some of the CAM modalities, such as acupuncture, herbal medicines, dietary omega-3 fatty acids, vitamins, and pulsed electromagnetic field show promising efficacy in reducing pain. While the use of CAM modalities for the treatment of RA continues to increase, rigorous clinical trials examining their efficacy are necessary to validate or refute the clinical claims made for CAM therapies.
Appropriate pain management is needed during the post-partum hospitalization period for preventing cesarean section (CS) related complications. Protocols of post-partum pain management should be planned based on the facilities of each center or region. The aim of current study was to compare the analgesic efficacy of oral methadone and intra muscular (IM) pethidine which the latter was routinely used in our center in post cesarean pain treatment. In this prospective double-blind clinical trial, women who were candidate for cesarean section were selected and randomized into two groups. All patients routinely received a single IM pethidine dose (50 mg) after CS in the recovery room. One group of patients received 0.7 mg/kg pethidine every 6 hour IM, and another group received 0.07 mg/kg oral methadone every 6 hour. Severity of pain assessed using visual analogue scale (VAS) score in 6, 12, 18 and 24 hour after surgery. Pain severity in methadone group at 6, 12, 18 and 24 hour post operation were 6.4 ± 0.9, 3.4 ± 0.8, 1.9 ± 1.1, 0.5 ± 0.5 (p < 0.05) and for patients in pethidine group were 6.6 ± 0.8, 3.4 ± 0.9, 2.1 ± 1.0 and 0.5 ± 0.5 (p < 0.05), respectively (Mean ± SD). Between groups differences in each follow up time were not statistically significant. There was no difference between groups in terms of complications and supplementary analgesic use. Considering the similar analgesic effects of methadone and pethidine, satisfaction of patients and nursing system with methadone use and the cost benefit of methadone, it can be recommended to use methadone for post operative pain relieving.
This study shows that a non-thermal pulse-modulated RF signal (PRF), configured to modulate calmodulin (CaM) activation via acceleration of Ca(2+) binding kinetics, produced an immediate nearly 3-fold increase in nitric oxide (NO) from dopaminergic MN9D cultures (P<0.001). NO was measured electrochemically in real-time using a NO selective membrane electrode, which showed the PRF effect occurred within the first seconds after lipopolysaccharide (LPS) challenge. Further support that the site of action of PRF involves CaM is provided in human fibroblast cultures challenged with low serum and exposed for 15min to the identical PRF signal. In this case a CaM antagonist W-7 could be added to the culture 3h prior to PRF exposure. Those results showed the PRF signal produced nearly a two-fold increase in NO, which could be blocked by W-7 (P<0.001). To the authors' knowledge this is the first report of a real-time effect of non-thermal electromagnetic fields (EMF) on NO release from challenged cells. The results provide mechanistic support for the many reported bioeffects of EMF in which NO plays a role. Thus, in a typical clinical application for acute post operative pain, or chronic pain from, e.g., osteoarthritis, EMF therapy could be employed to modulate the dynamics of NO via Ca/CaM-dependent constitutive nitric oxide synthase (cNOS) in the target tissue. This, in turn, would modulate the dynamics of the signaling pathways the body uses in response to the various phases of healing after physical or chemical insult or injury.
The transduction mechanism for non-thermal electromagnetic field (EMF) bioeffects has not been fully elucidated. This study proposes that an EMF can act as a first messenger in the calmodulin-dependent signaling pathways that orchestrate the release of cytokines and growth factors in normal cellular responses to physical and/or chemical insults. Given knowledge of Ca(2+) binding kinetics to calmodulin (CaM), an EMF signal having pulse duration or carrier period shorter than bound Ca(2+) lifetime may be configured to accelerate binding, and be detectable above thermal noise. New EMF signals were configured to modulate calmodulin-dependent signaling and assessed for efficacy in cellular studies. Configured EMF signals modulated CaM-dependent enzyme kinetics, produced several-fold increases in key second messengers to include nitric oxide and cyclic guanosine monophosphate in chondrocyte and endothelial cultures and cyclic adenosine monophosphate in neuronal cultures. Calmodulin antagonists and downstream blockers annihilated these effects, providing strong support for the proposed mechanism. Knowledge of the kinetics of Ca(2+) binding to CaM, or for any ion binding specific to any signaling cascade, allows the use of an electrochemical model by which the ability of any EMF signal to modulate CaM-dependent signaling can be assessed a priori or a posteriori. Results are consistent with the proposed mechanism, and strongly support the Ca/CaM/NO pathway as a primary EMF transduction pathway. The predictions of the proposed model open a host of significant possibilities for configuration of non-thermal EMF signals for clinical and wellness applications that can reach far beyond fracture repair and wound healing.