Full text of DOI:10.1007/BF03020945

REPORTS OF INVESTIGATION
319
Acupressure wristbands
do not prevent postop-
erative nausea and vom-
iting after urological
endoscopic surgery
Anil Agarwal MD,
Ashish Pathak MD,
Atul Gaur MD
Purpose: To evaluate the efficacy of acupressure wristbands in the prevention of postoperative nausea and vom-
iting (PONV).
Methods: Two hundred ASA I - II patients undergoing elective endoscopic urological procedures were included
in a randomized, prospective, double blind, placebo-controlled study. Spherical beads of acupressure wristbands
were placed at the P6 points in the anterior surface of both forearms in Group 1 patients (acupressure group,
n=100) whereas, in Group 2 (control group, n=100) they were placed inappropriately on the posterior surface.
The acupressure wristbands were applied 30 min before induction of anesthesia and were removed six hours
postoperatively. Anesthesia was induced with thiopental and maintained with nitrous oxide and oxygen, fentanyl,
isoflurane and vecuronium. The tracheas were extubated on the operation table after patients received neostig-
mine and atropine. Post operative nausea and vomiting were evaluated separately as none, mild, moderate or
severe at the time of patient’s arrival in PACU, then at six hours and twenty-four hours after surgery by a blind-
ed observer.
Results: In the acupressure group, 25 patients had PONV compared with 29 patients in the control group
(P = NS).
Conclusion: Application of acupressure wristbands at the P6 of both forearms 30 min before induction of anes-
thesia did not decrease the incidence of PONV in patients undergoing endoscopic urological procedures.
Objectif : Évaluer l’efficacité de bracelets d’acupression utilisés pour la prévention des nausées et des vomisse-
ments postopératoires (NVPO).
Méthode : Deux cents patients, ASA I - II, devant subir une intervention urologique endoscopique planifiée ont
participé à l’étude randomisée, prospective et à double insu contre placebo. Des bracelets de billes d’acupression
ont été placés aux points P6 de la face antérieure des deux avant-bras des patients du Groupe 1 (groupe d’acu-
pression, n=100) tandis que dans le Groupe 2, (groupe témoin, n=100), ils l’ont été, de façon inappropriée, sur
la face postérieure. On les a appliqués 30 min avant l’induction de l’anesthésie et retirés six heures après l’opéra-
tion. L’anesthésie comportait du thiopental, à l’induction, et du protoxyde d’azote, de l’oxygène, du fentanyl, de
l’isoflurane et du vécuronium. L’extubation trachéale a eu lieu à la salle d’opération après l’administration de
néostigmine et d’atropine. Un observateur objectif a évalué les nausées et les vomissements postopératoires
comme absents, légers, modérés ou sévères au moment où le patient est arrivé à la salle de réveil, puis six et
vingt-quatre heures après l’opération.
Résultats : Dans le groupe d’acupression, 25 patients ont eu des NVPO, comparativement à 29 patients du
groupe témoin (P = NS).
Conclusion : L’application de bracelets d’acupression en P6 aux deux avant-bras, 30 min avant l’induction de
l’anesthésie, n’a pas diminué l’incidence de NVPO chez des patients qui subissent une intervention urologique
endoscopique.
From the Department of Anaesthesiology & Critical Care Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow,
India.
Address correspondence to: Dr Anil Agarwal, Type IV / 48, SGPGIMS Campus, Lucknow, 226 014, India. Phone: 091-0522-440004-8,
Ext. 2473(0), 2474(R); Fax: 091-0522-440017, 440047, 440078; E-mail: aagarwal@sgpgi.ac.in
Accepted for publication January 9, 2000.
CAN J ANESTH 2000 / 47: 4 / pp 319–324

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CANADIAN JOURNAL OF ANESTHESIA
OSTOPERATIVE nausea and vomiting
(PONV) is associated with considerable
morbidity in anesthetic practice. Often, this
is a temporary phenomenon, but may con-
Acupuncture at P6 has produced good results in
the treatment of morning sickness,8,9 nausea and vom-
iting after chemotherapy.8 However, acupuncture at
P6 is invasive and may be associated, though rarely,
with side effects such as nerve damage and transmis-
sion of infectious disease. Acupressure is non-invasive
and is devoid of these complications. If acupressure is
found to be effective in preventing or minimizing
PONV, it may reduce the patient’s inconvenience,
decrease hospital stay and, thus, the total cost of treat-
ment. There have been reports suggesting that acu-
pressure can reduce the nausea due to morning
sickness,10 general anesthesia,11 cytotoxic therapy,1 2
and postoperative morphine administration.1 3 The
present study was aimed at validating the usefulness of
acupressure wristbands in preventing PONV in
patients undergoing endoscopic urological surgery in
the setting of distention of the renal pelvis or urinary
bladder which are known to induce additional afferent
stimuli for nausea and vomiting.1
P
stitute the most memorable distress for many patients
after an otherwise uncomplicated anesthetic and sur-
gical course. The stimulus for nausea and vomiting
arises from various sites throughout the gastrointesti-
nal tract. Additional stimuli for nausea and vomiting
include distention of the uterus, renal pelvis or urinary
bladder.1
The incidence of PONV may be as high as 60-70%
which is influenced by various factors in the perioper-
ative period including patient characteristics.2–6 The
medications used to alleviate PONV may be associat-
ed with side effects varying from lethargy, restlessness,
tachycardia and extrapyramidal symptoms.
Acupuncture and acupressure are based on the belief
that an individual’s well being depends on the balance
of energy in the body as well as the overall energy level.
It is hypothesized that energy flows in the body along
paths referred as meridians and that these techniques
restore the balance of energy by manipulating these
meridians.7 P6 ( Nei-Guan), a Chinese meridian point,
is specifically designated for the treatment of nausea and
vomiting. P6 is located on the anterior surface of the
forearm, approximately 1 cm deep to the skin, two
(body) inches proximal to the distal crease of the wrist
joint between the tendons of flexor-carpi-radialis and
palmaris longus. A body inch is equal to the width of
the interphalangeal joint of the patient’s thumb.
Methods
The study protocol was approved by our institutional
research committee, and informed consent was
obtained from all patients. Two hundred consecutive
patients (ASA I or II) of either sex, aged between 18
and 60 yr, undergoing endoscopic urological surgery
were included in this randomized, prospective, double
blind, placebo controlled study. Patients were assigned
to two different groups according to a computer-gen-
erated table of random numbers. One hundred patients
were in the acupressure group (Group 1) and 100 were
in the control group (Group 2). A spherical bead of
acupressure wristbands was placed at the P6 points on
both forearms in the acupressure group (Group 1)
patients. In the control group (Group 2), the spherical
bead of acupressure wristbands was placed on the pos-
terior surface. The acupressure wristbands were applied
30 min before induction of anesthesia.
The acupressure wristbands were applied by two
individuals specially trained in their proper applica-
tion. The accupressure wristband has an adjustable
strap, ¾ inch in width, with a spherical plastic bead
attached to it and Velcro fastener to prevent the head
from slipping from its position (Figure 1). The treat-
ment point P6 (Nei-Guan) is located on the anterior
surface of the forearm, approximately 1 cm deep to
the skin, two body inches proximal to the distal crease
of the wrist joint between the tendons of flexor-carpi-
radialis and palmaris longus (Figure 1). One body inch
is equal to the width of the interphalangeal joint of
patient’s thumb. The accupressure band was placed
snuggly around the wrist so that the patient felt gen-
FIGURE 1 Location of pericardium 6 (P6) meridian point and
the proper application of accupressure wristband; which is an
adjustable velcro strap, 3/4 inch in width, with a spherical plastic
bead attached to it.

Agarwal et al.: ACUPRESSURE AND PONV
321
TABLE I Demographic data
Acupressure group
(Group1; n=100)
Control group
(Group 2; n=100)
Age (yr)
36.5 8.2
46 / 54
56 10
34.2 6.1
51 / 49
61 12
Sex (M / F)
Weight (kg)
Height (cm)
164
6
160
7
Values are mean SD
TABLE II Number of procedures in each group
Acupressure group Control group
(Group 1; n =100) (Group 2; n =100)
DVIU
Cysto/panendoscopy
DJ Stunting
Uretrorenoscopy
Percutaneous nephrostomy 11
Cystolithopaxy 06
21
17
26
19
26
16
25
18
08
07
FIGURE 2 The duration of surgical procedures. Values are mean
SD; N/V = nausea/vomiting
DVIU = Direct visualization internal urethrotomy
DJ Stunting = Double J stunting
um. At the end of the surgical procedure, the tracheas
were extubated in the operating room after reversal of
the neuromuscular block with appropriate doses of
neostigmine and atropine. A blinded observer evaluat-
ed patients for the presence of PONV. The acupres-
sure wristband was removed six hours postoperatively.
Postoperative analgesia was provided with 100 mg
diclofenac im eight hourly along with 50 µg fentanyl iv
prn to keep the pain score <2 on a visual analogue scale
of 0 to 10. An anesthesiologist blinded to the therapy
registered the incidence of nausea and vomiting at three
different times in the first 24 hr postoperatively: on
arrival of the patient in PACU, and at six hours (time of
removal of acupressure wristband) and 24 hr after oper-
ation. The results were scored as described by Allen et
al.14 as none, nausea, retching/vomiting. Patients expe-
riencing both nausea and vomiting were included in the
vomiting group. For examining the severity of nausea
and vomiting, nausea was classified as none, mild, mod-
erate or severe. Vomiting and retching were not distin-
guished and their severity was classified by the number
of episodes over 24 hr: none, mild (0-2), moderate (3-
5), or severe (5).15 If the patient vomited, they were
given 4 mg ondansetron iv.
tle pressure without discomfort. The patient’s palm
and fingers were examined for any signs of excessive
compression due to the wristband. A pulse oximeter
was also placed on the index finger to confirm that
blood flow to the digits was adequate. Wristbands
were considered too loose and were tightened if a
wedge of paper could fit between the pressure band
and the skin. Forearms were raised by 60° at the elbow
and venous filling emptied normally in all cases. The
acupressure bands were loosely covered with gauze
and tape so that they could not be distinguished from
the placebo bands.
Exclusion criteria included patient refusal to partic-
ipate in the study, previous history of PONV and trav-
el sickness, impaired renal function with increased
urea and creatinine concentrations, diabetes mellitus,
obesity, patients receiving antiemitic medication, hist-
amine H2-receptor antagonist within 72 hr of surgery.
Anesthesia was administered by different anesthesi-
ologists using a standardized technique. No antiemitic
medication was given before or during operation. All
patients received 2 mg lorazepam po on the night
before surgery and two hours before surgery with sips
of water. Anesthesia was induced with 2 µg·kg– 1 fen-
tanyl iv and 4-5 mg·kg–1 thiopental iv, and maintained
with isoflurane 0 -1% and nitrous oxide 60% in oxy-
gen. Neuromuscular block was provided by vecuroni-
Patient characteristics in the two groups were
assessed using the unpaired Student’s t test. PONV
data were analyzed using z test to compare propor-
tions of occurrence in both the groups. Comparisons
between groups was performed for overall nausea and
retching/vomiting; then separately at various score
levels like none, mild, moderate and severe for nausea
and retching/vomiting. A P value of < 0.05 was con-
sidered significant.

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CANADIAN JOURNAL OF ANESTHESIA
TABLE III Severity of nausea and vomiting, and antiemitic requirements. Score is the maximum reported score over 24 hr along with
statistical analysis.
Acupressure group
(Group, n=100)
Control group
(Group 2, n=100)
Statistical analysis
P
Z
Power
Nausea
None
82
18
11
7
80
20
13
7
0.36
0.36
0.43
0.00
0.36
0.35
0.33
0.00
92.22
92.22
98.01
99.4
Nausea(A+B+C)
A = Mild
B = Moderate
C = Severe
Vomiting
0
0
None
Vomiting(A+B+C)
A = Mild
B = Moderate
C = Severe
Anti-emetic (1 dose)
93
7
5
2
0
91
9
6
3
0
0.52
0.52
0.31
0.45
0.30
0.30
0.38
0.33
95.96
99.74
99.95
100
6
7
0.29
0.39
99.84
effects or complications were observed due to the
placement of acupressure wristband in both the
groups and all patients felt comfortable wearing them.
Discussion
The P6 (Nei-Guan) meridian point in acupuncture has
been used to treat vomiting and other stomach ailments
in traditional Chinese medical practice. In 1990, Dundee
revealed that acupuncture or acupressure at the P6
meridian point was effective as a standard antiemitic in
the treatment of nausea and vomiting.9 The mechanism
of action of acupressure is not clear. It is postulated that
acupressure causes low frequency electrical stimulation of
the skin sensory receptors which may activate A-ß and A-
* fibres. These fibres synapse within the dorsal horn and
may, in turn, cause release of endorphins from the hypo-
thalmus. Increased levels of ß-endorphin concentration
have been reported in human cerebrospinal fluid after
acupuncture stimulation.16 It is also postulated that opi-
oids may have antiemitic effects mediated by the action
of ß-endorphins on µ receptors. Acupressure has been
shown to enhance gastric motility.1 7
Acupuncture or acupressure at P6 meridian point is
inconsistent in efficacy. Harmon,5 Dundee et al.11,12,18
and Fan,1 9 observed the efficacy of acupressure or
acupuncture at the P6 meridian. The important com-
ponent of this treatment includes the timing of the
stimulation20 and correct location.21 Lee et al.2 2 per-
formed a meta-analysis and found that non-pharmaco-
logical techniques including acupuncture, electro-
acupuncture, transcutaneous electrical nerve stimula-
tion, acupoint stimulation, and acupressure have more
effect than placebo in the prevention of PONV within
six hours of surgery in adults, but there was no benefit
FIGURE 3 Incidence of nausea / vomiting in the acupressure
and control groups at three different times.
Results
No patient was excluded after admission to the study.
Patients were comparable in both the groups as
regards to age, sex, height and weight (Table I).
Surgical procedures performed (Table II) and the
duration of the procedures (Figure 2) were compara-
ble in both groups. The acupressure group had a
slightly lower numerical incidence of nausea and vom-
iting compared with the control group but this differ-
ence was not statistically significant, (Figure 3), with a
relative risk ratio of 0.86. Severity of nausea and vom-
iting and anti-emetic requirements in the both the
groups were comparable using Z test and are shown
along with their power analysis in (Table III). No side

Agarwal et al.: ACUPRESSURE AND PONV
323
in children. O’Brien et al.23 found no apparent benefit
from the use of P6 accupressure during pregnancy, an
observation similar to the findings of Lewis et al.24 dur-
ing correction of strabismus. The present study was per-
formed in adult patients undergoing urological
endoscopic surgery.
Acupressure, when applied after induction of anes-
thesia, did not report favourable results.2 4 This
emphasizes the importance of application of acupres-
sure before induction of anesthesia. In our study the
acupressure wristbands were applied 30 min before
induction of anesthesia. The effect of combined use of
acupuncture and acupressure has also been studied by
Shenkman et al.25 in children undergoing tonsillecto-
my without any significant effect on PONV.
5 Harmon D, Gardiner J, Harrison R, Kelly A.
Acupressure and the prevention of nausea and vomit-
ing after laproscopy. Br J Anaesth 1999; 82: 387–90.
6 Watcha MF, Simeon RM, White PF, Stevens JL. Effect
of propofol on the incidence of postoperative vomiting
after strabismus surgery in pediatric outpatients.
Anesthesiology 1991; 75: 204–9.
7 Vincent CA, Richardson PH. The evaluation of thera-
peutic acupuncture: concepts and methods. Pain 1986;
24: 1–13.
8 Dundee JW, McMillan CM. Clinical uses of P6
acupuncture antiemisis. Acupunct Electrother Res
1990; 15: 211–5.
9 Dundee JW. Belfast experience with P6 acupuncture
antiemisis. Ulster Med J 1990; 59: 63–70.
10 Dundee JW, Sourial FBR, Ghaly RG, Bell PF. P6 acu-
pressure reduces morning sickness. J R Soc Med 1988;
81: 456–7.
11 Dundee JW, Ghaly RG, Bill KM, Chestnutt WN,
Fitzpatrick KTJ, Lynas AGA. Effect of stimulation of
the P6 antiemitic point on postoperative nausea and
vomiting. Br J Anaesth 1989; 63: 612–8.
12 Dundee JW. Ghaly RG, Fitzpatrick KTJ. Optimizing
antiemesis in cancer chemotherapy (Letter). BMJ
1987; 294: 179.
13 Ho CM, Hseu SS, Tsai SK, Lee TY. Effect of P-6 acu-
pressure on prevention of nausea and vomiting after
epidural morphine for post-cesarean section pain relief.
Acta Anaesthesiol Scand 1996; 40: 372–5.
14 Allen DL, Kitching AJ, Nagle C. P6 acupressure and
nausea and vomiting after gynaecological surgery.
Anesth Intensive Care 1994; 22: 691–3.
15 Tigerstedt I, Salmela L, Aromaa U. Double-blind com-
parison of transdermal scopolamine, droperidol and
placebo against postoperative nausea and vomiting.
Acta Anaesthesiol Scand 1988; 32: 454–7.
16 Clement-Jones V, McLoughlin L, Tomlin S, Besser GM,
Rees LH, Wen HL. Increased ß-endorphin but not met-
enkephalin levels in human cerebrospinal fluid after
acupuncture stimulation for recurrent pain. Lancet
1980; 2: 946–9.
17 Lin X, Liang J, Ren J, Mu F, Zhang M, Chen JDZ.
Electrical stimulation of acupuncture points enhances
gastric myoelectical activity in humans. Am J
Gastroenterol 1997; 92: 1527–30.
It is recognised that certain types of surgery are
associated with a higher incidence of PONV. In
adults, surgical procedures performed laproscopically
and otolaryngological, plastic, gynecological and oph-
thalmological surgical procedures have a higher inci-
dence of associated PONV.3 Fan19 in their study
included patients having surgery associated with a
high incidence of PONV such as laproscopic cholecys-
tectomy and gynecological procedures along with ton-
sillectomy and open cholecystectomy similar to the
studies by Harmon et al. 5 and Stein.2 6 In our study,
we included patients undergoing endoscopic urologi-
cal procedures to validate the usefulness of acupres-
sure in preventing PONV in the setting of distention
of the renal pelvis or urinary bladder which are known
to send additional afferent stimuli for nausea and vom-
iting.1 In this study, acupressure wristbands, applied
prior to the induction of anesthesia, in adult patients
listed for urological endoscopic surgery, did not offer
any benefit.
In conclusion, acupressure at P6 was ineffective in
preventing PONV in patients undergoing endoscopic
urological procedures.
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