Photoplethysmography-based assessment of varicose vein-related risk factors,exercise health beliefs,and venous refill time in healthcare professionals working in operating rooms and outpatient clinics

Abstract

Bacground

Impaired venous return is observed in healthcare professionals who spend long periods standing and sitting. This descriptive cross-sectional study was conducted to evaluate varicose vein-related risk factors, exercise health beliefs, and venous refill time in healthcare professionals working in operating rooms and outpatient clinics by photoplethysmography.

Method

The study sample consisted of 100 healthcare professionals without a diagnosis of peripheral venous insufficiency. Data were collected using a descriptive characteristics form, the Health Belief Model Scale for Exercise, the Short-Form McGill Pain Questionnaire, and photoplethysmography.

Result

This study found that OR nurses had shorter venous refill times and experienced more pain due to prolonged standing, despite their high health beliefs about exercise.

Conclusion

Healthcare professionals working in operating rooms should be screened for venous insufficiency and trained regarding the practices to prevent venous insufficiency, such as lying down, elevating legs, and using elastic stockings.

Keywords

Healthcare workers occupational factors venous insufficiency photoplethysmography

Introduction

Chronic venous insufficiency (CVI) is a global health problem with a high prevalence that significantly affects the quality of life, results in losses in the workforce, and imposes significant diagnostic and treatment costs.¹ Risk factors associated with the development of CVI include female gender, obesity, hypertension, pregnancy, sedentary lifestyle, smoking, and chronic constipation.^1–3 Literature has reported a higher prevalence of varicose veins in individuals with prolonged standing, women, and those working in hot and humid environments.³ In contrast, however, Kroeger et al.⁴ (2004) associated the prevalence of varicose veins with predominantly sedentary sitting and standing work positions.

The primary pathological mechanism underlying CVI is an increase in venous pressure, known as venous. Prolonged standing further increases the incidence of venous hypertension.^4,5 Venous diseases are diagnoses based on a combination of clinical findings, physical examination, and diagnostic modalities. Doppler ultrasound, plethysmography, venography, computed tomography, and magnetic resonance imaging are commonly used in patients with suspected venous disease.^6,7 As a viable alternative to Doppler ultrasound, photoplethysmography (PPG) is a non-invasive diagnostic test, which is used to assess calf muscle pump function, global venous reflux, and venous outflow obstruction.⁸

CVI is a chronic disease with serious socioeconomic consequences that negatively affect the quality of life with the loss of labor force and the onset of edema appearance.⁹ Work posture and occupation are among the most controversial predisposing factors associated with venous disease. Lapropoulos et al. (1995) examined the distribution and extent of venous reflux in the lower extremities of symptom-free vascular surgeons, who were typically classified as leading a life of prolonged standing, in comparison to a group of symptom-free volunteers by color-flow duplex imaging.¹⁰ In this study, venous reflux was more frequently seen among symptom-free vascular surgeons than normal individuals of a nonmedical vocation. Compared to the general population, healthcare professionals have a significantly higher prevalence of CVI by 58%, with varicose veins prevalence of 22.1%, on average.¹¹ A study in Turkey found that 50.4% of nurses suffered from CVI, and there was a significant correlation between the discrepancy in daily ankle circumference between the left and right ankles and the average years of working in the hospital.¹² These findings indicate an increased prevalence of CVI in healthcare professionals compared to the general population. For this reason, there is a need for early detection and preventive measures to protect healthcare professionals from developing CVI and varicose veins.

Materials and Methods

This descriptive cross-sectional study was conducted between 16 November 2022, and 6 March 2023, to investigate risk factors for varicose veins, exercise health beliefs, and venous refill time in healthcare professionals working in operating rooms and outpatient clinics.

The population of the study consisted of healthcare professionals working in the operating rooms and outpatient clinics of a private hospital in Istanbul. The sample size was determined by power analysis, with a two-way hypothesis requiring a minimum of 84 participants to achieve 80% power (1-β = 0.80) with a 0.05 margin of error. The sample of the study consisted of 100 healthcare professionals working in the operating room and outpatient clinic who agreed to participate in the research. Healthcare workers previously diagnosed with peripheral venous insufficiency, history of DVT, previous venous operation, or injection sclerotherapy were not included in the study. Healthcare workers may underestimate their diseases and their preventive behaviour is generally weak. They usually start treatment after the disease is diagnosed.¹³ The healthcare workers who participated in the study were asked whether they had ever consulted a doctor about peripheral venous insufficiency and whether they had undergone any tests related to it, and checked from the health system. The people included in the study were healthcare professionals and this declaration was accepted.

Data collection instruments

Descriptive Characteristics Form

This form consisted of 12 items for collecting data about (age, gender, height, weight, smoking, etc.) the healthcare professionals.

Short-Form McGill Pain Questionnaire (SF-MPQ)

This scale was originally developed by Melzack in 1987.¹⁴ Turkish reliability and validity study of the scale was conducted by Biçici¹⁵ and Güneş (2010). The SF-MPQ consists of three sections. The first section includes 15 groups of descriptive words that reflect different aspects of pain. The scores from this section were used to calculate three pain scores: sensory pain score (ranging from 0 to 33), perceptual pain score (ranging from 0 to 12), and total pain score (ranging from 0 to 45). Higher scores indicate greater pain intensity. The second section consists of five word groups ranging from “mild pain” to “unbearable pain” that allow participants to indicate the severity of their pain. The third section uses a visual analog scale to assess the individual’s current pain intensity. In this study, Cronbach’s alpha coefficient of the scale was calculated as 0.70.

Health Belief Model Scale for Exercise (HBMS-E)

This scale was developed by Villar et al.¹⁶ as a tool to assess individuals’ exercise health behaviors. The Turkish validation and reliability study of the scale was conducted by Yılmaz and Kartal (2021).¹⁷ The scale consists of 25 items scored on a five-point Likert scale and includes five sub-dimensions: general health values, beliefs about the significance of not exercising, beliefs about reducing the risk (threats) of disease through exercise, beliefs that the benefits of exercise outweigh its costs, and beliefs about the disadvantages of not exercising. Higher scale scores indicate stronger exercise health beliefs. In this study, Cronbach’s alpha coefficients ranged from 0.66 to 0.87.

Photoplethysmography

Photoplethysmography is an effective screening method for evaluating venous function. It is a noninvasive technology that is used as part of the venous assessment of the lower extremities. Although duplex ultrasound remains the industry gold standard for assessment, there are many situations in which access or expertise is not available. The measurement of venous refill time with PPG, one measure of venous insufficiency, is becoming increasingly more prevalent in research settings; however, PPG is underused in clinical settings.^8,18 PPG is a method that measures capillary refill in the skin after venous emptying caused by exercise.¹⁸ In addition, it provides a serious advantage by providing quantitative data in muscle pump measurement. Measurement results can be stored and graphically documented.^19–22 A light-sensitive diode is placed on the skin approximately 8–10 cm above the medial malleolus of the ankle, and the reflected infrared light is detected by the diode. The amount of reflected light depends on the volume of blood in the skin capillaries. During the test, the subject sits on the edge of the examination table and allows the foot to hang down while performing eight consecutive foot extensions and flexions. The time it takes for the device to return to the reference value after the exercise is known as the refill time. A shorter refill time indicates increased venous reflux in the legs and provides an assessment of the severity of venous disease. By applying a tourniquet proximal to the detector, superficial systemic insufficiency can be differentiated from deep systemic pathology. If the shortened refill time returns to normal after tourniquet application, deep systemic pathology can be ruled out. VRT was recorded as a normal vein (healthy vein) at >25 s, mild insufficiency at 20–24 s, moderate insufficiency at 10–19 s, and severe insufficiency.^19,23

Data Collection

The healthcare professionals were informed about the study, and informed consent was obtained for participation. The healthcare professionals first completed the descriptive characteristics form. Then, SF-MPQ and HBMS-E were applied. Following the questionnaires, photoplethysmography (ELCAT Vasoquant VQ1000 D-PPG^®, Germany) was used to determine venous refill time. Before photoplethysmography, the room temperature was maintained at 20–23°C. To avoid pressure on the thigh area, the healthcare professional was instructed to remove tight clothing. Before the measurement, the healthcare professional was seated and allowed to rest for 10 min. After taking necessary precautions for safety, the healthcare professional was positioned in a sitting position. An infrared light-emitting diode was placed on intact skin approximately 8–10 cm above the medial malleolus for the photoplethysmography. The healthcare professionals were then asked to flex and extend their legs eight times while seated. The test was repeated with a tourniquet proximal to the detector to differentiate between superficial system insufficiency and deep system pathology. A tourniquet is applied proximal to the detector to differentiate superficial system failure from deep system pathology. The normalization of the shortened refill time after the tourniquet is applied rules out deep system pathology. Therefore, a tourniquet was used. The results were recorded for both legs. Data collection took an average of 20–25 min.

Statistical analysis

IBM SPSS Statistics 23.0 (Statistical Package for Social Sciences, IBM Corp., Armonk, NYC, USA) was used to analyze the collected data. Descriptive statistical methods (numbers, percentages, means, standard deviations, and minimum and maximum values), the Pearson chi-squared test, and the Mann–Whitney U test were used to compare demographic variables and other qualitative and quantitative data. Spearman correlation analysis was used to examine the relationship between the Health Belief Model Scale for Exercise and the Short-Form McGill Pain Questionnaire. Hierarchical regression analysis was used to predict the Health Belief Model Scale for Exercise and venous refill time in healthcare professionals working in operating rooms and outpatient clinics. The internal consistency Cronbach’s alpha coefficient was used to assess the reliability of the scales used in the research. The statistical significance level was set at p < 0.05.

Results

The comparison of the descriptive characteristics of the healthcare professionals who participated in the study is presented in Table 1. The chi-squared test revealed a significant association between shoe preferences and the departments of healthcare professionals (χ2 (2) = 12.341, p < 0.05). The results of the Cramer’s V test demonstrate a statistically significant, moderate level of association between the two categorical variables under study. This indicates that the variables are related to a certain extent and that this relationship is not due to random chance (r = 0.351).

Table 1.

The comparison of the descriptive characteristics of the healthcare professionals (n = 100).

Variables	Operating room worker (n = 50)		Outpatient clinic worker (n = 50)		Test	Degree of freedom	p-value
Categorical variables	n	(%)	n	(%)	χ2	SD	p
Sex
Female	29	43.9	37	56.1	2.184	1	0.139^a
Male	21	61.8	13	38.2	2.184	1	0.139^a
Smoking status
Yes	19	61.3	12	38.7	1.683	1	0.195^a
No	31	44.9	38	55.1	1.683	1	0.195^a
Alcohol use status
Yes	1	100	0	0	1.01	1	0.315^b
No	49	49.5	50	50.5	1.01	1	0.315^b
Chronic disease status
Yes	3	100	0	0	1.375	1	0.241^a
No	47	48.5	50	51.5	1.375	1	0.241^a
Tight clothing preference
Yes	5	83.3	1	16.7	1.596	1	0.207^a
No	45	47.9	49	52.1	1.596	1	0.207^a
Shoe preference
Generally sports shoes	37	43	49	57	12.341	2	0.002^b
Generally classic shoes	8	100	0	0
Sport and classic equally	5	83.3	1	16.7
Previous surgery status
Yes	2	100	0	0	0.51	1	0.473^a
No	48	49	50	51	0.51	1	0.473^a
Compression stockings usage status
Yes	0	0	0	0			^c
No	50	50	50	50			^c
Continuous variables	$\bar{X}$ ± $S_{\bar{X}}$	Min-max	$\bar{X}$ ± $S_{\bar{X}}$	Min-max	SD	t	p
Age	37.22 ± 11.37	20–59	34.26 ± 9.55	21–55	98	1.409	0.162
BMI^d	25.80 ± 5.06	16.02–41.23	25.94 ± 4.16	18.52 ± 35.16	98	0.151	0.880
Standing time at work	9.50 ± 1.52	7–12	3.80 ± 1.29	1–6	98	20.127	0.000
Number of glasses of water drunk per day	6.62 ± 2.25	2–12	6.28 ± 2.09	3–12	98	0.781	0.436

^aContinuity Correction.

^bPearson Chi-Square.

^cStatistics could not be calculated due to insufficient data.

^dBMI: Body Mass Index.

A significant difference was found in the duration of standing at work between healthcare professionals working in outpatient clinics and operating rooms (t = 20.127, p < 0.05). The calculated effect size (d = 4.06) indicated a very large difference.

Table 2 shows the distribution of mean scores for the total scale and sub-dimensions of the Health Belief Model Scale for Exercise and the Short-Form McGill Pain Questionnaire among healthcare professionals working in operating rooms and outpatient clinics. The difference between the HBMS-E total and beliefs about the disadvantages of not exercising sub-dimension mean scores of the healthcare professionals working in operating rooms was found to be statistically significantly higher than that of healthcare professionals working in outpatient clinics (p < 0.05). In addition, the scores for sensory pain, total sensory pain, perceived pain, and total pain intensity were significantly higher in the healthcare professionals working in operating rooms than in the healthcare professionals working in outpatient clinics (p < 0.05).

Table 2.

The distribution of mean scores for the total scale and sub-dimensions of the Health Belief Model Scale for Exercise and the Short-Form McGill Pain Questionnaire among healthcare professionals working in operating rooms and outpatient clinics.

Scales	Sub-dimensions	Operating room worker		Outpatient clinics worker		U	p
Scales	Sub-dimensions	Median	Average of ranks	Median	Average of ranks	U	p
HBMS-E	General health values	12	45.8	12	55.2	1.485	0.100
	Beliefs about the significance of not exercising	12	47.44	12	53.56	1.403	0.272
	Beliefs about reducing the risk (threats) of disease through exercise	27	49.99	27	51.01	1.275	0.86
	Beliefs that the benefits of exercise outweigh its costs	23.5	50.08	23	50.92	1.271	0.884
	Beliefs about the disadvantages of not exercising	12	38.16	17	62.84	1.867	0.000
	HBMS-E total score	82	40.57	89.5	60.43	1.746	0.001
SF-MPQ	Sensory pain score	4	59.88	0.5	41.12	781	0.000
	Perceptual pain score	0	49.50	0	51.50	1.300	0.464
	Total sensory and perceptual pain score	5	59.56	0.5	41.44	797	0.001
	Pain severity	2	60.93	0.5	40.07	728.5	0.000

HBMS-E = Health Belief Model Scale for Exercise, SF-MPQ = Short-Form McGill Pain Questionnaire, U = Mann Whitney testi.

Table 3 shows the comparison of mean venous refill times for healthcare professionals working in operating rooms and outpatient clinics. The venous refill times of the right and left legs were found to be shorter for healthcare professionals working in operating rooms than for those in outpatient clinics (p < 0.05).

Table 3.

The comparison of mean venous refill times for healthcare professionals working in operating rooms and outpatient clinics.

Leg	Operating room worker		Outpatient clinics worker		U	p
Leg	Median	Average of ranks	Median	Average of ranks	U	p
Right leg	14	37.75	24	63.25	1.887.50	0.000
Left leg	13	37.50	24	63.50	1.900	0.000

U: Mann Whitney testi.

Discussion

The present study is significant because it is the first of its kind in the literature to investigate the relationship between risk factors associated with varicose veins, exercise health beliefs, and venous refill time in healthcare professionals in operating rooms who spend prolonged periods standing and in outpatient clinics who spend intermittent periods standing.

The main pathology that causes chronic venous insufficiency is an increase in venous pressure, i.e. venous hypertension. Standing in the same position for a long time is one of the reasons that increases venous hypertension.²⁴ The easiest calf muscle exercises are intermittent stepping or seated ankle movements. These exercises, which are performed several times every half hour, provide a serious advantage to lower extremity venous circulation.²⁵ With insufficient leg movement, the blood from the heart to the feet stays there due to venous pooling. Venous pooling in the lower extremities results in edema, leg swelling, increased foot and leg temperature, and the development of varicose veins.²⁶ Prolonged standing or sitting is a risk factor for chronic venous insufficiency.^1,11

In our study a key difference between outpatient clinic healthcare and OR professionals is that the latter remains quite stationary without activation of the calf muscle pump, while the former may walk around the clinic and activate their calf muscle pump. This study showed that individuals working in operating rooms had longer standing times (p < 0.001), and shorter venous refill times in the right and left legs (p < 0.001) compared to those working in outpatient clinics. This study is important for the objective diagnosis of venous refill time in healthcare professionals working in operating rooms. It is crucial to intervene before symptoms manifest in healthcare professionals with risk factors. A study conducted in France showed a significant correlation between prolonged standing or sitting and varicose vein symptoms and complaints such as heavy feeling in the legs, swelling, and restlessness.²⁷ Lapropoulos et al. found that the rate of venous reflux was higher in surgeons compared to the control group.¹⁰ Abou-El-Wafa et al. reported a higher prevalence of varicose veins in nurses who had worked in the emergency department, intensive care unit, and operating room for more than 5 years, worked more than 6 h per day, and maintained a static standing position. Another study found an increased incidence of venous reflux in nurses who stood for more than 4 h²⁵⁶ In a study by Łastowiecka-Moras (2017) conducted on 10 healthy young participants, venous refill time was assessed using photoplethysmography before and after 20 min of standing with no additional load, as well as while sitting with the knee joints flexed at 90°. The results indicated a shortened venous refill time in the participants who stood without additional load.²⁸ The results of this study are consistent with the literature and show that healthcare professionals in operating rooms who engage in prolonged standing have shorter venous refill times.^26,29,30 Healthcare professionals working in the operating room remain immobilized for long periods without activating the calf muscle pump.

Leg pain or discomfort and leg swelling are recognized as early symptoms of problems in the venous system.³¹ A study by Bishera et al. (1986) conducted on 25 healthy subjects reported that 21% of the participants experienced abnormally shortened venous refill times in extremities with initially normal venous refill times after standing for 5 h or more. In addition, participants experienced pain and swelling in the extremities with shortened venous refill time. Studies in the literature also report complaints of pain in industrial workers and healthcare professionals who stand for long periods.³⁰ In our study, healthcare professionals in operating rooms were found to experience high levels of sensory pain and pain intensity. Physically, leg pain and fatigue can interfere with daily activities and lead to reduced productivity at work.³² A prospective study conducted in Denmark found that prolonged standing at work was associated with an increased risk of hospitalization for varicose veins.³³

Regular exercise or physical activity is widely recognized as having a positive impact on human health.³⁴ Exercise aims to prevent venous blood accumulation in the lower extremities by activating the calf muscle pump. Exercises that increase ankle mobility play a role in eliminating calf muscle pump dysfunctions, alleviating venous hypertension and regulating venous flow.^25,34 Studies in the last 10–12 years have shown that ankle movements are the key biomechanical element in calf muscle pump function.³⁵ In one study, they restricted the movements of the ankle in healthy volunteers and showed that there was a significant decrease in the efficiency of the pump along with a decrease in venous pressure during exercise.³⁶ Calf muscle strength may affect venous return efficiency. Back et al. stated that normal walking motion is required for calf muscle pump activation, which requires dorsi flexion exceeding 90^o.³⁷ Despite the known benefits of physical activity, its practice remains below desired levels. Beliefs and attitudes about maintaining and improving health play a critical role in shaping behavior. Once behavioral beliefs and attitudes are identified, tailored health training or treatment methods can be developed for individuals.¹⁷ For example, an individual who believes in the need to exercise and has the self-efficacy to engage in such activity is more likely to adopt and maintain this behavior. The present study showed that the mean HBMS-E total score was significantly higher in operating room personnel compared to outpatient personnel. This finding suggests that individuals in operating rooms with a shorter venous refill time have a stronger belief in the importance of exercise. In a standing person, only the contraction of the muscles and the vein valves provide the return of venous blood, especially in the legs. When the leg muscles contract, they pressurize the deep veins between them and send the venous blood upwards. The valves here prevent venous blood from escaping back. The valves in the perforating veins prevent the passage of blood from deep veins to superficial veins. When these valves fail to function properly, the blood in the deep veins escapes back to the superficial veins after the contraction of the muscles and increases the pressure here, thus forming vein pockets that show enlarged folds in the weak places of the superficial veins.³⁸ Leg exercises are effective in increasing venous return to the heart. During leg exercises, calf muscle pump, compression of deep leg veins and venous valves help increase blood flow to the heart.³⁹

Conclusion

In conclusion, prolonged standing or sitting is a significant risk factor for venous insufficiency. Therefore, it is crucial to regularly assess the venous system in the lower extremities of individuals engaged in these activities. Healthcare professionals neglect their health while providing healthcare services to their patients. Healthcare professionals should be screened for signs of venous insufficiency in perspective, and healthcare professionals working in the operating room should be informed about taking intermediate steps or performing ankle movements while sitting, which contribute to lower extremity venous return circulation.

Footnotes

Acknowledgements

Gökçe Şirin, Selda Karaveli Çakır, Osman Pirhan, Hasan Toz, İlknur Çalışkan and Semra Erpolat Taşabat “Photoplethysmography-Based Assessment of Varicose Vein-Related Risk Factors, Exercise Health Beliefs, and Venous Refill Time in Healthcare Professionals Working in Operating Rooms and Outpatient Clinics” thank you for your contribution.

Author contributions

Study design S.E., G.Ç., Data collection S.E., İ.Ç., S.K.Ç. Analysis S.E., S.E.T., S.K.Ç. Literature search S.E., O.P.,G.Ç.,H.T.,S.K.Ç. Manuscript preparation SE,SKC,HT

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Ethical statement

Guarantor

ORCID iDs

Selda Karaveli Cakir

Sinem Eryiğit

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