original research

Do anxiety, stress, or depression have any impact on pain

perception during shock wave lithotripsy?

Muammer Altok, MD; Abdullah Akpinar, MD; Mustafa Güne

, MD; Mehmet Umul, MD; Kadir Demirci, MD;

Ercan Baş, MD

Süleyman Demirel University, Faculty of Medicine, Department of Urology, Isparta, Turkey; Süleyman Demirel University, Faculty of Medicine, Department of Psychiatry, Isparta, Turkey

Cite as: Can Urol Assoc J 2016;10(5-6):171-4. http://dx.doi.org/10.5489/cuaj.3445

Published online May 12, 2016.

ment it with the aid of ﬂuoroscopy or ultrasound. Adverse

effects of SWL are well known. The most important adverse

effect during the procedure is pain perception, which has

been suggested to be related to many factors (stone size,

stone location, shock frequency or voltage, skin aperture of

the shock wave, the type of the SWL device, etc.).³

The signiﬁcance of anxiety, stress, and depression on pain

perception during SWL is not clear. The aim of this study

was to evaluate the effect of anxiety, stress, and depression

on pain perception during SWL. Additionally, we evaluated

the relationship between pain perception during SWL and

the level of anxiety, stress, and depression.

Abstract

Introduction: The most important adverse effect during shock wave

lithotripsy (SWL) is pain perception. In this study, we evaluated

the effect of anxiety, stress, and depression on pain perception

during SWL.

Methods: From November 2013 to December 2014, 189 consecu-

tive patients undergoing SWL for kidney stones were evaluated pro-

spectively. Patient characteristics (age, sex, body mass index [BMI],

urologic intervention history, the presence of a double-j catheter,

and stone-related parameters) were also recorded. Anxiety, stress,

and depression states were assessed before the ﬁrst procedure using

the Depression, Anxiety, and Stress Scales (DASS-42), which is

a self-report scale. The degree of pain perception was evaluated

with a 10-point Visual Analogue Scale (VAS) at the end of the ﬁrst

SWL session.

Results: There were no statistically signiﬁcant differences in terms

of VAS scores during SWL between patients with and without

anxiety, stress, or depression (p >0.05). Furthermore, no statisti-

cally signiﬁcant relationships were found between VAS scores and

patient age, sex, side of the stone, presence of a double-j stent,

number of stones, and SWL experience (p >0.05).

Methods

Between November 2013 and December 2014, a pro -

spective study was conducted with consecutive patients

allocated in order of application, who underwent SWL for

kidney stones. The sample size was calculated based on

a previous study by assuming an a error of 0.05, a 1-b

error of 0.2 (power of 80%) and an effect size I pl:0.51.

Power calculations determined that a total sample size of

0 patients would be sufﬁcient. The study was approved

by the local ethics committee and informed consent was

obtained from all patients. Patient data, including age, sex,

body mass index (BMI), urologic intervention history (previ-

ous SWL, operation), the presence of a double-j catheter,

and stone-related parameters (size as maximum diameter,

number) were recorded before the procedure.

Conclusions: According to our ﬁndings, anxiety, stress, or depres-

sion seemed to have no impact on pain perception during SWL.

Introduction

Diclofenac sodium 75 mg (Dikloron , Deva, Istanbul,

The development of shock wave lithotripsy (SWL) in 1980

significantly changed the management of urinary tract

Turkey) was administered intramuscularly 30‒45 minutes

before the SWL session for pain control. After the appli -

cation of diclofenac sodium, the patient’s anxiety, stress,

and depression states were assessed using the Depression,

Anxiety, and Stress Scales (DASS-42), a self-report scale

administered before the ﬁrst procedure. All patients under-

went 1‒3 sessions of SWL in relation to treatment responses

stones. It is currently accepted as the primary treatment

option for urinary stones.

SWL produces high-energy shock waves through an elec-

trical discharge. The shock waves are transmitted through

the tissues and focused onto a renal/ureteral stone to frag-

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2016 Canadian Urological Association

E171

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Results

in our department using an ELMED Multimed Classic litho-

tripter (ELMED, Ankara, Turkey) electrohydraulic system.

SWL treatment was initiated with at a 7 KV energy level

and progressively increased to 16‒21 KV while consider-

ing the pain perception of the patient. At a frequency of 60

shock waves per minute, 2500 shock waves were applied

for each patient at every session. Additional analgesics were

not administered during the procedure.

We included 189 patients in this study. Demographic

data, stone-related parameters, and patients’ characteristics

including VAS, anxiety, stress, and depression scores are

shown in Table 1.

The comparison of VAS scores and anxiety, stress, and

depression statuses according to the DASS-42 scale are

described in Table 2. There were no statistically signiﬁcant

differences in terms of VAS scores during SWL between

patients with and without anxiety, stress, or depression

(p >0.05, Table 2).

Exclusion criteria for this study were the presence of any

untreated urinary infections, nonsteroidal anti-inﬂammatory

drug intolerance or allergy, psychiatric drug consumption

(

such as antidepressants and anxiolytics), the inability to

complete the DASS-42 form or evaluate pain with the visual

analog scale (VAS), and absolute contraindications for SWL

The comparison of the severity of anxiety, stress, and

depression, and VAS score are shown in Table 3. There was

no statistically signiﬁcant difference between the anxiety,

stress, and depression subgroups according to VAS scores (p

>0.05, Tables 3, 4). Furthermore, no statistically signiﬁcant

relationships were found between VAS scores and patient

age, sex, side of the stone, presence of a double-j stent, num-

ber of stones, and SWL experience. The VAS score seemed

to increase with increasing BMI and stone size; however,

statistical signiﬁcance for this was not detected (Table 5).

(

pregnancy, bleeding diatheses).

The degree of pain perception was evaluated with a

0-point VAS at the end of the procedure. Only the VAS

results of the ﬁrst SWL session were evaluated. Statistical

analysis was performed using the Statistical Package for the

Social Sciences version 12.0 software program (SPSS 12.0

for Windows; SPSS Inc., Chicago, IL, U.S.). Continuous

variables were presented as a mean (± , standard deviation

[

SD]). The distribution of numerical variables was analyzed

separately in each group to establish nonparametric require-

ments. We performed chi-square tests to compare categori-

cal variables. The signiﬁcance of differences between groups

was estimated using the Mann-Whitney U test and differ-

ences were analyzed. Bivariate comparisons were examined

using Kendall’s correlation coefﬁcients (r) and values were

corrected for ties. Two-tailed hypothesis tests were used for

statistical analysis and all of these differences were consid-

ered signiﬁcant at p <0.05.

Discussion

Pain during SWL is thought to be related to two different

origins. First, is the effect of the shock waves on the cuta-

neous and subcutaneous structures (skin, muscle, ribs, and

subcostal nerves). The second is related to the kidney and

to increases in intrapyelic pressure, distention of the renal

capsule, or obstructions caused by fragmented stones. The

type of SWL machine, shock wave voltage and number,

skin aperture, stone size, stone location, sex, age, and BMI

are thought to affect pain perception during SWL.¹

However, published data on this subject are contradictory.

,3,4,7-12

Table 1: Patients and stone characteristics (n=189)

Age ± SD

43.92 ± 13.98

Vergnolles et al, Tokgoz et al, and Berwin et al reported

that female patients have signiﬁcantly higher pain percep-

tion and require more analgesic treatments. Alternatively,

Sex (%)

Female

Male

59 (31.2%)

130 (68.8%)

BMI ± SD

27.22 ± 4.20

Salinas et al and Tailly et al reported that there was no

Side of stone (%)

Right

Left

89 (47.1%)

100 (52.9%)

Table 2. The presence of anxiety, stress, depression, and

VAS score

Double-J stent status (%)

Yes

Number (%)

VAS score ± Sꢀ

p value

32 (16.9%)

157 (83.1%)

All patients

189 (100%)

4.62 ± 1.45

Anxiety

Yes

Stone number ± SD

Stone size (mm) ± SD

SWL session no ± SD

VAS score ± SD

1.41 ± 1.04

10.5 ± 3.91

2.3 ± 0.86

115 (60.8%)

74 (39.2%)

4.55 ± 1.37

4.74 ± 1.57

0.458

Stress

Yes

4.62 ± 1.45

7.35 ± 7.05

10.95 ± 8.84

6.73 ± 7.96

136 (72.0%)

53 (28.0%)

4.64 ± 1.47

4.58 ± 1.41

.786

.995

Anxiety score ± SD

Stress score ± SD

Depression

Yes

VAS: Visual Analogue Scale.

Depression score ± SD

BMI: body mass index; SD: standard deviation; SWL: of shock wave lithotripsy; VAS: Visual

Analogue Scale.

140 (74.1%)

49 (25.9%)

4.64 ± 1.48

4.59 ± 1.38

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Pꢃꢄꢅ pꢂꢆꢇꢂptꢄꢁꢅ duꢆꢄꢅꢈ ꢉꢊꢁꢇk wꢃvꢂ ꢀꢄtꢊꢁtꢆꢄpꢉy

Table 3. Comparison between the severity of anxiety,

stress, and depression, and VAS score

Table 4. Correlation between anxiety, stress, and

depression levels, and VAS score

VAS score

Number (%)

Mean ± Sꢀ

VAS score

Number (%)

p value

Sꢀ

Anxiety (n=74)

Mild

Moderate

Severe

Anxiety

Yes

22 (29.7%)

26 (35.1%)

4.55 ± 1.85

4.73 ± 1.46

4.92 ± 1.47

115 (60.8%)

74 (39.2%)

3.04 ± 2.35

14.04 ± 6.69

0.019

0.027

0.793

0.776

0.402

0.260

0.831

Stress

Yes

Stress (n=53)

Mild

Moderate

Severe

136 (72.0%)

53 (28.0%)

6.52 ± 4.52

22.32 ± 6.93

0.067

-0.151

0.309

0.156

20 (37.7%)

19 (35.8%)

14 (26.4%)

5.05 ± 1.76

4.53 ± 1.07

4.00 ± 1.04

Depression

Yes

140 (74.1%)

49 (25.9%)

2.89 ± 2.77

17.69 ± 7.78

0.107

-0.137

0.110

0.220

Depression (n=49)

Mild

Moderate

Severe

16 (32.7%)

21 (42.9%)

12 (24.5%)

4.75 ± 1.34

4.62 ± 1.50

4.33 ± 1.30

SD: standard deviation; VAS: Visual Analogue Scale.

was used to detect anxiety or depression.¹³^,¹⁶^,¹⁷The STAI is

a self-report form, does not have a cutoff point for detect-

ing the presence of anxiety, and only measures the level of

SD: standard deviation; VAS: Visual Analogue Scale.

signiﬁcant relationship between pain perception and sex.

Berwin et al reported that BMI is related, while Vergnolles

anxiety. HADS is also a self-report form and has a cutoff

et al and Tokgoz et al reported that BMI in not related to

point,but it evaluates the level of anxiety and depression;

however, subgroup evaluations are not possible.¹⁹Unlike

these studies, we used the DASS-42 form in our study. The

DASS-42 form is also a self-report form and includes 42

pain perception. Tailly et al reported that stone size and

number are related to pain perception, unlike Berwin et al

who reported that there is no signiﬁcant correlation between

pain and stone size and the number of stones.

Pain is a subjective description. Other than pathophysi-

ological factors, psychological and social factors may also

Table 5. Descriptive statistics for patient and stone

characteristics

4,15

The relationship between pain

affect pain perception.

and anxiety in SWL patients has been evaluated in a few

VAS Score

Mean ± Sꢀ)

Variables

p value

0.402

0.308

0.183

(

2,13

Franceschi

Age

0–39

studies and the results were controversial.

et al reported that anxiety cannot be predictive of pain.

4.78 ± 1.65

4.55 ± 1.20

4.34 ± 1.40

0–59

Sex

Female

Male

BMI

8.5–24.9

5–29.9

Alternatively, Vergnolles et al investigated an anxiety and

depression status effect on pain perception during SWL

treatment in 164 patients and reported that depressed and

4.73 ± 1.50

4.58 ± 1.43

anxious patients experienced more pain. In the current

study, we investigated the effect of existing anxiety, stress,

and depression before the SWL treatment on pain percep-

tion during the SWL session. To our knowledge, this is the

ﬁrst study that has evaluated anxiety, stress, and depression

at the same time in a large patient series; it is also the only

study to evaluate the stress factor and its relationship to

pain. In our study, no signiﬁcant relationships were detected

between pain perception and anxiety, stress, or depression

among the subgroups.

4.31 ± 1.29

4.69 ± 1.55

4.85 ± 1.37

Side of stone

Right

Left

4.76 ± 1.43

4.50 ± 1.46

.172

.950

Double-J stent status

Yes

4.63 ± 1.48

4.60 ± 1.43

Stone number

We only evaluated anxiety, depression, and stress levels

before the ﬁrst SWL session and VAS was only evaluated in

the ﬁrst SWL session. In the previously mentioned studies,

this topic was unclear. These previous studies suggested

that anxiety and pain perception increased in accordance

4.56 ± 1.49

4.52 ± 1.20

5.21 ± 1.31

0.108

0.240

Stone size (mm)

7 mm

8–14 mm

14 mm

4.41 ± 1.44

4.61 ± 1.50

4.91 ± 1.29

with the increase in SWL session numbers. Therefore, the

evaluation of anxiety, depression, and VAS status for every

session, especially in the same patients, can cause conﬂict-

ing results due to the cumulative experience.

In similar studies, the State-Trait Anxiety Inventory (STAI)

or Hospital Anxiety and Depression Scores (HADS) form

Urologic background

SWL

4.60 ± 1.35

4.65 ± 1.66

.941

BMI: body mass index; SD: standard deviation; SWL: of shock wave lithotripsy; VAS: Visual

Analogue Scale.

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questions. The advantage of this form is that it evaluates

anxiety, stress, and depression simultaneously. Also, it has

cutoff points for detecting the presence of anxiety, stress,

and depression, and can evaluate their severity within sub-

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Conclusion

Based on our ﬁndings, we can conclude that existing anxi-

ety, stress, or depression before the SWL treatment may not

be related to pain perception during the SWL session.

Competing interests: The authors declare no competing ꢀnancial or personal interests.

This paper has been peer-reviewed.

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humans as pain phenotypes. J Pain 2004;5:377-84. http://dx.doi.org/10.1016/j.jpain.2004.06.003

Correspondence: Dr. Muammer Altok, Süleyman Demirel University, Faculty of Medicine, Department

of Urology, Isparta, Turkey; muammeraltok@sdu.edu.tr

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