Abstract

Interventional pulmonologists require a unique set of skills including precise motor abilities and physical endurance, but surprisingly the application of ergonomic principles in the field of bronchoscopy remains limited. This is particularly intriguing when considering the significant impact that poor ergonomics can have on diagnostic aptitude, income potential and overall health. It is therefore imperative to provide comprehensive education to physicians regarding the significance of ergonomics in their work, especially considering the introduction of advanced diagnostic and therapeutic procedures. By implementing simple yet effective measures (e.g. maintaining neutral positions of the wrist, neck and shoulder; adjusting the height of tables and monitors; incorporating scheduled breaks; and engaging in regular exercises), the risk of injuries can be substantially reduced. Moreover, objective tools are readily available to assess ergonomic postures and estimate the likelihood of work-related musculoskeletal injuries. This review aims to evaluate the current literature on the impact of procedure-related musculoskeletal pain on practising pulmonologists and identify modifiable factors for future research.

Tweetable abstract

Ergonomics of bronchoscopy is currently understudied but has wide-ranging implications including operator efficiency and overall health of the bronchoscopist. https://bit.ly/3PtJus4

Introduction

Ergonomics, derived from the Greek words ergo (work) and nomos (law), is the science of designing the job to fit the worker, optimising the interface between the worker, the equipment and the work environment [1]. Its goal is to minimise injury and maximise efficiency by optimising the interaction of the operator with tools, tasks and workplace. Ergonomic analyses are widely applied in various fields to enhance performance and reduce the risk of error and injury [2–6]. Risk factors for work-related strain injury include repetitive manoeuvres, prolonged awkward postures, manipulation of the hands and contact stress. Repetitive motion injuries are frequent and disabling among medical professionals, particularly interventional pulmonologists [7–10]. While existing literature highlights the negative impact of musculoskeletal pain on physicians, it primarily focuses on gastroenterology, otolaryngology, anaesthesia and surgery [11–14]. The volume of bronchoscopic procedures performed by interventional pulmonologists has significantly increased, making it crucial to prevent overuse injuries that could limit patient care. The National Institute of Occupational Safety and Health recommends workstation design principles to avoid static loads, reduce fixed work postures and prevent excessive bending or neck forward positions of more than 15° [15]. The field of ergonomics in bronchoscopy is still in its early stages with limited research available. This review seeks to evaluate the current prevalence and impact of procedure-related musculoskeletal pain among practising pulmonologists. It also provides useful guidance on proper posture and positioning. Furthermore, we identify key modifiable factors for future research to enhance the understanding and application of ergonomics of bronchoscopists, ultimately improving their wellbeing and performance.

Search strategy

The search strategy was as follows: original articles that included the words or variations of “ergonomics of bronchoscopy” or “work place ergonomics” or “pulmonologist and ergonomics” and also the word “ergonomics” were included. Peer-reviewed studies in any language from inception to June 2023 from the following databases were evaluated: PubMed, MEDLINE, Scopus and Cochrane Central Register of Controlled Trials (CENTRAL).

Scope of the problem

The field of interventional pulmonology has undergone significant changes, expanding the diagnostic and therapeutic capabilities of flexible bronchoscopy. These advances aim to reduce procedure-related complications and enhance patient comfort, but the physical strain and cumulative trauma experienced by the performing physicians are often overlooked [16, 17]. Current bronchoscopes have seen minimal changes since their introduction in 1967 [18]. The required torque and thumb lever pressure vary depending on airway anatomy and sampling location. Repetitive hand movements, high pinch force, sustained awkward postures, procedure volumes, years of practice and prolonged standing are associated with these symptoms, leading to overuse injuries [19–24]. Injuries can be severe and may lead to work load reduction, missed days off work, reduction of activities outside of work and long-term disability. Thumb and wrist injuries, including “endoscopist's thumb” (de Quervain's tenosynovitis) and carpal tunnel syndrome, are common in the long term [25, 26]. Prolonged standing and lead aprons are implicated in back and neck injuries [27]. Two-piece aprons and antifatigue mats are recommended to decrease pressure on the lumbar and cervical disks as well as delay muscle fatigue [28, 29].

The exact prevalence of bronchoscopy-related injuries among bronchoscopists is unknown, but surveys indicate that 39% of pulmonologists experience pain during bronchoscopy, particularly in the back, shoulder, wrist, thumb and neck [30]. However, this issue is often under-appreciated, with many physicians (79%) not seeking treatment. Longer procedures lasting over 30 min have a higher risk of pain (relative risk 1.568, 95% CI 1.053–2.190, p=0.024) [30].

Similar observations have been made in gastroenterology, where higher procedure volume (>20 cases per week), longer hours spent performing endoscopy (>16 h per week) and increased years of practice correlate with higher rates of endoscopy-related injury [28].

In the largest survey of bronchoscopists to date, up to 51% reported procedure-related musculoskeletal pain, with left upper extremity (49%), neck (47%) and lower back (46%) being the most affected areas [21]. Younger physicians with less experience and smaller glove sizes were more likely to report pain. The mentor–mentee concept in pulmonary fellowship may contribute to this association, as mentors often supervise procedures rather than performing them.

A similar study has shown that experienced bronchoscopists have less muscle burden and improved ergonomic positioning compared to less experienced ones [20].

Although the literature on ergonomics in the pulmonary subspecialty is limited, there are available data from gastroenterology and surgical subspecialties that can be informative. One of the most studied ergonomic models is the surgeon performing laparoscopic surgery [31, 32]. Current literature explores ergonomic concepts such as optimal bed height, monitor placement, adjustable screen heights, screen sizes, image quality and standing mat technology, which have been associated with improved provider comfort [33–40].

The prevalence of procedure-related musculoskeletal pain in surgical specialties is high, with rates ranging from 40% in general surgery to 97% in vascular surgeons [41–45]. Similarly, otolaryngologists report a prevalence of 79% for musculoskeletal pain [46, 47].

In gastroenterology literature, certain demographic characteristics such as female sex, smaller glove size and short stature have been recognised as risk factors for procedure-related pain [12, 29, 48]. However, the impact of physical attributes such as height, sex, hand size (which are mostly nonmodifiable) and bronchoscope design on ergonomics has been minimally explored.

While a survey among interventional pulmonologists did identify small glove size as a significant risk factor for musculoskeletal pain, height and sex were not found to be significant factors. It worth mentioning that the only 23 of the 161 respondents were women [21].

Performing rigid bronchoscopy is also associated with increased odds of pain, especially for individuals performing one or more procedures per week [49]. The odds of pain further increased for those performing two or more procedures per week. Force measurements during rigid bronchoscopy have demonstrated high peak forces, particularly during scope insertion, which may increase the risk of thumb and wrist injuries.

While efforts to improve ergonomics are underway, more research and advancements in technology are needed to optimise procedural ergonomics in bronchoscopy. Technological advancements in bronchoscope design, such as rotational-head bronchoscopes, show potential for improved ergonomics when targeting specific areas like the left upper lobe [20].

Enhancing the bronchoscopy experience and minimising risk

For the purpose of our discussion, we will classify the bronchoscopy unit into three distinct components: the bronchoscopist (including the proceduralist bronchoscope, shoes, attire, apron), the bed and the monitor (with image processor). Within each of these categories, there are multiple elements that can be adjusted and optimised to improve the bronchoscopy experience and reduce the likelihood of injuries.

Position of equipment: monitor

The initial step involves assessing the modifiable elements within the workplace environment. The monitor's height should be adjustable to accommodate the endoscopist's height and preferred viewing distance. In the absence of specific ergonomic data for bronchoscopy, we draw insights from studies on surgical laparoscopy. These studies have demonstrated that placing monitors directly in front of surgeons at eye level, as opposed to off to the side or at the head of the bed, effectively reduces muscle activity in the neck and shoulders [50, 51]. Although the optimal distance of the monitor has not been formally studied, it will depend on factors such as monitor size, image clarity and individual bronchoscopist preference [50, 51]. Estimates based on computer simulation and laparoscopists show that the optimal distance between the bronchoscopist and a 14-inch monitor is between 52 and 182 cm (20.5–63.8 inches), which allows for the least amount of image degradation [48, 50, 51]. Many modern monitors are larger (19–26 inches), which allows for placement farther from the bronchoscopist without losing image quality. The optimal viewing angle requires the monitors to be placed in such a way that the middle of the screen is at or below eye level, preferably between 15° and 25° below [48]. Alternatively, monitors should be placed with a height 20 cm lower than the height of the bronchoscopist [50, 51]. In cases where the monitor is fixed or non-adjustable, it is important to consider the bronchoscopist's height and assign them to a specific room to ensure comfort and prevent potential neck strain. Maintaining a straight posture and avoiding slouched or crooked positions is essential. If there is an obstructing C-arm or similar equipment within the line of vision, it is advisable for individuals to turn their entire body towards left or right screen, rather than solely relying on neck rotation.

Optimising bed height and patient positioning

Two crucial factors to consider are the height of the bed and the positioning of the patient on it. Bed height affects both spine and arm position; surgical data again suggest that optimal bed height is between elbow height and 10 cm below elbow height [52]. It is vital to have an adjustable procedure table or bed that enables proper alignment of the elbow, shoulder and back. Insufficient bed height can result in stooping, while placing the patient in the centre requires leaning forwards [52]. Ideally, the patient's head should be positioned at the edge of the bed. In environments with limited resources and nonadjustable beds, it may be necessary to customise the beds for each bronchoscopist to mitigate the risks of injuries associated with beds that are too high or too low. By implementing these modifications, one can automatically achieve a correct posture with ears above shoulders, a straight back and a properly aligned neck and spine. A tip by the authors is to raise the bed to the level of the operator's umbilicus. Some have suggested that if there is a bend in the scope, the bed is too high and if one if stooping over, the bed is too low. The perfect height is one where the bronchoscopist can keep their elbow and arm close to their body and still maintain a straight posture.

The image processor

In the bronchoscopy suite, it is common for most processors to be positioned on the left side of the bronchoscopist, as per the design of the flexible bronchoscope. When a young trainee enters the suite, their primary focus is often on obtaining the bronchoscope and proceeding with the procedure, without considering the condition of the umbilical cord. If the cord contains a coil, it adds weight and increases resistance when manoeuvring the scope, resulting in strain. So, the initial step should be to remove the coil and straighten the scope, which facilitates easy manipulation of the bronchoscope.

Optimising body positioning and movement techniques

Maintaining flexibility and avoiding unnecessary stress on the body is of utmost importance, making is essential to avoid locking the knees because this can lead to strain. Instead, individuals should maintain a slight flex in the knees. The feet should be positioned approximately shoulder-width apart. Keeping the elbows in a neutral position is also recommended. It is worth noting that movements can involve the entire body, and individuals can use their wrists for lateral movements. Practising such movements with different body parts can be beneficial, because it reduces the reliance on a single body area and minimises the risk of injury.

Flexible bronchoscope: which hand should hold it?

This is always an interesting pro versus con debate at various bronchology conferences. Dr Ikeda, who designed the flexible bronchoscope, was left-handed. So, the overarching belief is that he designed the bronchoscope to be held with the left hand up [53]. Interestingly, there is a statement in the Journal of Bronchology and Interventional Pulmonology that says “Dr. Ikeda repeatedly stated that the flexible bronchoscope was not constructed to be used easily for a left-handed person because he himself was left-handed. The reason why the flexible bronchoscope is held in the left hand is to make it simpler for the right hand (the dominant hand for 90% of the population) to operate the forceps and other auxiliary equipment.” [53]. Because the design is made with the right-handed person in mind, the light source and cable are located on the left-hand side of the scope. This naturally makes it ergonomically challenging to hold it with the right hand. However, it is easier to do a bronchoscopy in the left lung while holding the scope with the right hand. Some argue that the cable will be in the way owing to its location on the left side, similar to the fibrescopes, in which if the scope is held in the right hand and viewed through the right eye, the light source and the cable to the light source would cross in front of the left eye of the operator and would therefore be in the way. As authors, we have no preference and recommend that alternating hands during bronchoscopy is actually ergonomically friendly to avoid muscle fatigue.

Many new navigational technologies have shown some promise by minimising the need for a bronchoscopist to manoeuvre the bronchoscope through the airway because it is self-propelled and either self-navigating or guided by a joystick.

Rotation function at the working channel insertion port

The dial at the working channel insertion port allows clockwise or counterclockwise rotation of 120°, which assists in difficult-to-reach segments. The impact of bronchoscope design on ergonomics and muscle activity has been looked at by a few studies but robustly validated assessments are scarce [20]. Gilbert et al. [20] suggested that technological advances in bronchoscope design may have the potential to improve procedural ergonomics. In their study, the bronchoscopic targets chosen included the posterior subsegment of the anterior segment of the right upper lobe (RB3), lateral subsegment of the anterior segment of the right lower lobe (RB8) and the posterior subsegment of the apical-posterior segment of the left upper lobe (LB1+2). Two groups took turns using different bronchoscopes (standard flexible bronchoscope versus rotational-head flexible bronchoscope (RHFB)) focusing on the target area. There was no statistically significant difference in terms of improvement in ergonomic positioning (p=0.15) during access to RB3 or RB8, even when they controlled for age, sex or skill level. However, during access to the left upper lobe (LB1+2), there was a statistically significant improvement in the ergonomics when utilising RHFB (p=0.036) compared with a flexible bronchoscope.

One abstract suggested that experienced bronchoscopists demonstrated improved ergonomics with a rotational-head bronchoscope when performing simulated bronchoscopy [54]. The ergonomic benefits suggested by these studies with the use of RHFB at certain lung segments (specifically the left upper lobe) suggests that further studies should be undertaken to expand on the trends found.

Lead apron

Advanced procedures that use C-arm fluoroscopy also confer a risk to the bronchoscopist. For example, the operator is burdened with an increase in static load on the neck, shoulders and back because of the use of lead aprons. When possible, a two-piece lead apron for procedures that require fluoroscopy is recommended, which transfers some of the weight of the apron from the shoulders to the hips and reduces upper-body strain.

According to studies conducted in Korea, lead aprons, thyroid shields and lead glasses are worn by approximately 93–100%, 81–100% and 38–40% of operators, respectively [27].

A study compared body part discomfort, fatigue and ease of movement while wearing two-piece lead suits, one-piece suits and one-piece suits with waist belts [27]. The average weight of one-piece suits was 8 kg (17.9 lbs) versus 3–4 kg (6.1–8 lbs) for the top and 3–6 kg (6.2–13 lbs) for the bottom of a two-piece suit. While not significant, they noted trends towards increasing thoracic discomfort (p=0.07) while wearing a one-piece suit and greater ease of movement (p=0.07) for subjects wearing a two-piece suit or a one-piece suit with a waist belt. The use of lead aprons has not been systematically studied in interventional bronchoscopy, but a two-piece lead apron offers a theoretical advantage because the load can be more evenly distributed between the spine and pelvis.

Ergonomics assessment methods

Several ergonomic assessment methods have seen significant increases in overall prevalence of use in the USA over the past 20 years. Some of these include Rapid Upper Limb Assessment (RULA), Rapid Entire Body Assessment (REBA), Psychophysical Upper Extremity Data, Strain Index and Threshold Limit Value (TLV) for Hand Activity Level [55]. However, there are no data to suggest this is the trend within the medical community except for research purposes.

Rapid Upper Limb Assessment

RULA is a well-accepted and validated survey method originally developed to assess ergonomic postures to estimate the risk of injury [19, 20, 56]. It considers postural load requirements of job tasks/demands on the neck, trunk and upper extremities. RULA scores are general reflections of potential ergonomic strain during manoeuvres of the body and can often suggest a more thorough assessment for workplace safety. RULA scoring is also meant to be simple and straightforward, allowing assessment with little training as opposed to very complicated training or specialty background. Scores range from 1 to 7 with 1 indicating normal posture and 7 indicating increased muscle strain and the need for immediate implementation of change. Depending on one's posture, the scoring system correlates with negligible, low, medium or very high musculoskeletal disorder risk. Scores in the 3–4 range suggest that people are working outside of suitable ranges of motion or may be within appropriate working postures but that repetitive action, loading or exertional forces are required and potentially detrimental. Further investigations are encouraged to make the workplace safer. A score of 5–6 suggests that both workplace postures and repetitive muscle use/loading are unsafe [57, 58]. The major limitations of RULA are that it does not consider the duration of the task or available recovery time; it only allows the evaluator to assess one employee's worst-case posture at one point in time, requiring the use of representative postures. Lastly, it requires separate assessment of right and left sides of the body, although in most cases you will be able to quickly determine which side of the body has the greatest exposure to musculoskeletal disorder risk.

The use of the RULA to evaluate ergonomics within bronchoscopy appears novel; however, the RULA has been used within numerous workplace situations, including for computer programmers, dentists and laparoscopic surgeons [59–62].

In a study by Gilbert et al. [20], a comparison of RULA scores across skill levels revealed that beginner bronchoscopists had higher mean RULA scores when compared with non-beginners (4.85 versus 4.42, p=0.007). Participants with increased height (p<0.001) and larger glove size (p=0.001) were also found to have significantly less muscle usage. However, this did not result in improved ergonomic (RULA) scores. Furthermore, comparison of electromyography (EMG) effort across skill levels revealed that nonexpert (beginner and intermediate) level bronchoscopists demonstrated increased muscle activity when compared with expert level bronchoscopists (p=0.007). Age was found to be colinear with experience level; however, there were no significant differences in EMG burden or RULA scoring as age increased. This was the first study to capitalise on the use of surface EMG to study the ergonomics of bronchoscopy. These data suggest that muscle usage decreases and ergonomic scoring improves as bronchoscopic experience increases.

Taking care of you: ergonomic essentials for your practiceImproving posture during bronchoscopy

To enhance posture during bronchoscopy and reduce strain, adopting an ergonomic or “athletic” stance is recommended. The stance involves maintaining a neutral neck and back position without hyperextension or flexion, keeping shoulders back and chest out, distributing weight evenly between both legs, avoiding knee hyperextension, and positioning feet hip-width apart and directed towards the bronchoscopy screen. Using this stance consistently can help decrease excessive strain on the neck, shoulders, back and knees.

Utilising personal accessories for comfort

Several personal accessories can be beneficial in mitigating the physical toll of long hours on your feet during bronchoscopy. Compression stockings may enhance circulation during lengthy procedures. Cushioned support mats with downward sloping edges have been shown to decrease back strain and leg discomfort. In the absence of such mats, cushioned insoles can encourage postural changes and provide comfort during prolonged standing [25]. One systematic review suggested that a moderate level of evidence exists to support the use of cushioning materials for the reduction of perceived musculoskeletal discomfort of the lower limb and the lower back while standing at work [63]. Implementing these accessories can contribute to better ergonomics and alleviate discomfort.

Incorporating ergonomic practices into routineMaintaining physical fitness

Maintaining physical fitness significantly aids endurance during long days of bronchoscopy. Bronchoscopy can be physically strenuous, and having good stamina and physical strength can make a significant difference in overall wellbeing. Despite the challenges of finding consistent time to exercise as a trainee or consultant, it is important to prioritise even a few days a week. Experienced bronchoscopists often recommend practices like yoga or consistent stretching.

Practice points

To ensure adherence to ergonomic principles, performing a brief ergonomic time out before procedures can be highly beneficial. This entails taking 60 s or less to review posture (stance), bed and monitor height adjustments, and pedal positioning. Taking micro breaks for a few seconds during a challenging case to rest the scope and shake out the hands can help reduce upper limb pain. A recent meta-analysis suggested that scheduled micro breaks between prolonged procedures are recommended [64]. Additionally, incorporating a few minutes of stretching exercises between cases or at the end of the day can help alleviate tension. An often overlooked but crucial aspect of improving bronchoscopy ergonomics is optimising the room setup. Because poor monitor placement has been identified as a risk factor for musculoskeletal injuries, the first step is to improve the sight line by adjusting the height appropriately. If possible, the monitor should be 20 cm lower than the bronchoscopists height, with the centre of the screen falling at 15–25° below eye level, accommodating the resting eye angle. Additionally, maintaining an optimum distance between the monitor and the proceduralist is crucial. The favourable distance is estimated between 52 cm and 182 cm, which is a wide range, but the takeaway here is that it should not be too close or too far. Adjusting the height of the bed is a simple yet impactful measure to ensure proper posture. Ideally, the bed should be set at a height approximately between elbow height and 10 cm below elbow height. The floor pedals for fluoroscopy, cryotherapy or electrocautery should be easily accessible and within reach without straining. A useful tip is to place one foot on the edge of the pedal as a pivot or guide to know where it is, so that one does not have to keep looking down to locate the pedal each time. Discomfort in the left hand and wrist often arises when performing bronchoscopic procedures in the left lung, particularly the left upper lobe. Positioning an extra monitor to the left of the patient can alleviate the issue. Oftentimes, the monitor may not be completely adjustable in preexisting rooms; however, considering these factors when seeking future employment is advised.

Proper scope-handling techniques

Finding the most ergonomic and neutral way to hold the bronchoscope is extremely important; however, this is probably the hardest part of incorporating ergonomics into practice during training. A key concept to bear in mind is keeping the scope straight and in the most neutral position possible. This serves to improve the efficacy, efficiency and ergonomics of the procedure. Consistently minimising external loops in the universal cord is vital. Using gauze or a washcloth to reduce grip pressure is a small tweak in practice that many have found extremely helpful. When entering the left bronchus, the bronchoscopist can step over to the patient's right side and use the monitor to the left. This maintains a neutral position for the left hand and head during left lung examination. Adjusting the rotatory knob on the bronchoscope can also make it easier to access the left upper lobe easier. Although opinions may vary, alternating hands while navigating various airway segments can help alleviate strain on one hand. This also helps because then one can use a left-hand pinky grip technique when holding the scope in the right hand, and the right-hand pinky grip technique when holding the scope in the left hand during advanced procedures. All these are done in an attempt to improve the ergonomics of the proceduralist.

Conclusion

There is increasing evidence of work-related injuries among bronchoscopists, yet specific guidelines for bronchoscopists are lacking. To address this, a team approach involving specialists from occupational medicine, bronchoscopy nurses, technicians and physicians should establish an ergonomics committee to study and develop a protocol for the bronchoscopy suite. A standardised, ergonomically centred approach to teaching bronchoscopy should be implemented, incorporating essential endoscopy teaching competencies and effective feedback provision to minimise endoscopy-related injuries. Improving the design of the bronchoscope and bronchoscopy suite is crucial. Manufacturers should prioritise ergonomic improvements, while endoscopists should adopt ergonomic approaches during training. Recommendations from other specialties, such as gastroenterology and laparoscopic surgery, should be considered. As advanced technologies are adopted for diagnostic precision and patient safety, the safety and wellbeing of the endoscopist should not be overlooked. Bronchoscopists may be subjecting themselves to repeated cycles of musculoskeletal pain and connective tissue damage, which could affect their careers. While efforts to improve ergonomics are underway, more research and advancements in technology are needed to optimise procedural ergonomics in bronchoscopy.

Points for clinical practice

There appears to be an increased prevalence of work-related musculoskeletal injuries among bronchoscopists.

However, the additional physical strain and exposure to cumulative trauma on the person actually performing the bronchoscopy are often overlooked.

There is a need to further explore causative factors and educate physicians regarding ergonomics at work.

Footnotes

Provenance: Submitted article, peer reviewed.

Conflict of interest: All authors have nothing to disclose.

Received July 10, 2023.Accepted August 28, 2023.Copyright ©The authors 2023http://creativecommons.org/licenses/by-nc/4.0/

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