Keywords
surgical lighting - disposable instruments - lighted retractors - skin burns - overhead
lighting
Current Lighting Methods in Operating Rooms
Current Lighting Methods in Operating Rooms
Surgical performance in the operating room (OR) is supported by effective illumination,
which mitigates the inherent environmental, operational, and visual challenges associated
with surgery. Okoro et al describe three critical components to optimize operating
light as illumination: (1) centering on the surgeon's immediate field, (2) illuminating
a wide or narrow field with high-intensity light, and (3) penetrating into a cavity
or under a flap.[1] Furthermore, optimal surgical illumination reduces shadow, glare, and distortion
in visualization of the surgical site. However, achieving these principles is more
complex than at first glance, requiring a detailed examination of the variables that
comprise surgical illumination. In brief, efficacious surgical illumination combines
sufficient ambient light with the ability to apply focused light at specific operative
stages and angles. But, brighter is not always merely better; rather, a nuanced approach,
cognizant of the challenges inherent in the OR theater, can provide for a thoughtful
exploration of how surgical illumination can be utilized to the best of its ability,
ensuring a safe and smooth surgery for all.
There are currently four predominant methods of illumination utilized in the surgical
field: surgical lighting systems (SLS), lighted retractors, headlights, and operating
microscopes. Current methods of illumination address the fundamental needs of illumination,
largely intensity and control, in slightly different ways. For traditional open surgeries
across surgical disciplines, SLS, commonly referred to simply as OR lights, are broadly
utilized to illuminate the OR during procedures. Lighted surgical retractors, on the
other hand, are relatively more recent innovations that provide in-field focused illumination
targeted to the surgical site. To promote increased mobility and manipulation of the
light field, however, surgeons may elect to wear headlights. Operating microscopes
are exclusively utilized in microsurgery and provide the advantages of magnification
and reverse illumination. Each illumination method carries its own distinct advantages
and disadvantages, and use is dependent on the surgeon as well as the operation itself.
Current illumination methods are limited by the lack of mobility, repetitive and time-lengthy
adjustments, sterilization, and contamination concerns, nonoptimal illumination, inefficiencies,
and time delays. Knulst et al highlighted the ergonomic concerns around overhead lighting
systems, noting that every 7.5 minutes the adjustment of a two-arm pendant luminaire
system occurred.[2] The cited reason for initiating luminaire actions was to reestablish lighting at
surgical sites, and at adjusted angles, particularly in large, narrow but deep, and
multiple wounds. Knulst et al also emphasized that complications, such as mechanical
issues, that were encountered during luminaire actions increased the median time of
adjustment, thus adding to the overall duration of surgery.
In addition to the exact need for visualization, there is also a requirement for a
nuanced approach to delivering light at the surgical site. Traditional OR lights often
provide high-intensity, directional light, which serves as beneficial up to a threshold.
A great amount of light directed toward a surgical site allows for increased reflection
off structures, which provides for effective contrast. Contrast here refers to the
ability to confidently differentiate between different structures at the surgical
site, including microstructures. However, a consistently applied light source which
is too intense can, in fact, cause glare, washing out the details of the surgical
site and hence mitigating contrast. The relationship between contrast and glare is
thus in a delicate balance, with the exact illumination threshold dependent on the
specific structures and surgery at hand. In simpler terms, brighter is not always
better when it comes to visualization. Therefore, targeted, modulatory lighting is
recommended for parsing out the details of the surgical site and allowing contrast
to inform the surgeon's understanding of the anatomy. In this way, a base level of
lighting which is moderately intense, with the option to apply enhanced high-intensity,
buildable light for specific subtasks, is preferential for balanced visualization
throughout the surgery.
In line with the effects on visualization, high-intensity, conventional OR lighting
can also adversely affect surgeons' health and performance over time. Photoreceptors
in the eye are highly sensitive to stimuli, and may be affected depending on the duration,
intensity, wavelength, and intermittence of light. Surgeons are particularly vulnerable
to such effects, as surgeons work under illumination conditions that are high-intensity
and long duration, over multiple years. In the short term, this condition manifests
itself as eye fatigue, or the general symptoms of mild pain, headache, and sensitivity
around the eyes. Indeed, studies have suggested that extended exposure to high-intensity
light in the OR may contribute to eye fatigue specifically in surgeons.[3] In the long-term, sustained exposure to nonmodulated illumination sources may result
in permanent photochemical damage, as the eye loses its ability to protect the retina.
The adverse effects of hyperintense light sources on surgeons are beginning to be
recognized in the literature. For example, in one meta-analysis of over 5,000 surgeons,
Stucky et al found that over 25% of surgeons reported eye strain as an occupational
health hazard.[4] OR light source was one of multiple OR ergonomic factors considered. Future studies
should aim to capture the effects of light-derived eye fatigue and strain among surgeons,
to measure the long-term impact. Therefore, moderate, buildable light with the option
for directed, enhanced illumination is cited as optimal for surgeons to promote visualization,
as well as reduce eye fatigue and strain.
Further analysis corroborates that central issues with overhead SLS derive from the
pendant arms, which allow the possibility of collision and/or drift, and also contribute
to eye fatigue due to overhead lighting. Moreover, SLS represent a potential source
of contamination by way of the surgical light handles, despite coverage with sterile
light handles or sleeves. Schweitzer et al revealed that in hip replacement surgery
procedures in their hospital, 50% of randomly selected sterile light handles contained
a significant amount of bacterial culture.[5] Given that sterile surgical light handles are often manipulated during the procedure
to expose the patient to more or less light, there exists the potential to transfer
bacteria between the light handle, the surgeon or adjuster's gloves, and the wound
site, particularly if luminaire adjustments occur often throughout the course of a
procedure.
Practicing surgeons concur with the above issues, and further add concerns on the
clinical experience of alternative light sources, such as headlights and lighted retractors.
Qualitative survey analysis of 12 breast surgeons concluded that 92% of surgeon respondents
did not prefer to utilize headlights during surgery, citing insufficient light for
deep cavities, presence of shadows and glare, head and neck strain, continuous adjustment,
and potential source of contamination as reasons for nonpreference.[6] Other complaints traditionally have been the unwieldiness of cables related to lighted
retractor systems on the surgical field, as well as the tethering of a cabled headlight
to the surgeon, limiting mobility. Surgeon respondents' main contentions with fiber
optic lighted retractors centered on heat concerns and the perception that lighted
retractors provide less than optimal lighting.
In the current illumination landscape, there exists an urgent need for a light source
that is nimble, sterile, functionally simple, and visually superior. In the words
of Knulst et al:
“A sound surgical lighting solution will provide always good illumination at a wide
range of locations simultaneously, thus minimizing the need for and effect of luminaire
repositioning. As small-entrance deep wounds were reported to be difficult to illuminate,
the development of tailored lighting solutions might be advisable for these cases
. . . the surgeon should be able to perform this task with minimal effort and by paying
minimal attention to this secondary task.”[2]
Takeaways
-
The main illumination methods used in surgery are OR lighting, lighted retractors,
headlights, and operating microscopes.
-
Each method carries advantages and disadvantages driven by function and ease of use.
-
OR lights are frequently adjusted, notably every 7.5 minutes, and 50% of previously
sterile light handles have been shown to foster bacterial growth.
-
Light which is too bright can introduce glare, which thus impedes the ability to appropriately
visualize contrast.
-
Similarly, too-bright light can result in strain, fatigue, and permanent photochemical
damage to surgeon's eyes.
-
Practicing surgeons contend issues with current options and express interest in more
innovative, effective light sources.
Safety
Burns and Fires
The risk for burns due to light sources during surgery is well-documented in the literature,
inclusive of fiber optic light cables, headlights, overhead OR lights, and operating
microscopes. Fiber optic light cables, such as those attached to headlights or lighted
retractor systems, are largely considered in the literature to be a major burn risk
due to the propensity to record temperatures as high as 437°F.[7] Case reports of patient burns due to contact with fiber optic cables are described.
Headlights themselves and even overhead OR lighting are also recorded as causes of
patient burns. Operative microscopes pose a significant thermal injury risk to patients,
as the working distance between light source and surgical site is relatively small,
thus increasing the energy absorbed by the patient and hence the skin's vulnerability
to burn. Surgical fires are an additional inherent risk of surgical illumination,
specifically with regards to fiber optic light cables. Strategies to avoid burns and
fires, as well as the advantages and disadvantages of such strategies, are also discussed.
“While the healthcare community has made great strides in preventing surgical fires,
we must not be complacent.”[8]
-Scott Lucas, PhD, PE, Director of Accident and Forensic Investigation at ECRI Institute
Multiple clinical case studies report on burns caused by fiber optic cables, headlights,
and/or overhead OR lights. Fiber optic cables and cords are often attached to lighted
retractors or headlights, and thus used in illumination among a great number of surgical
specialties, fields, and procedures. Fiber optic cables are subject to achieving dangerously
high temperatures, recording as high as 437°F within 10 minutes.[7] Sandhu conducted a quantitative study in which light cables were measured for temperature
as well as propensity to cause skin burns.[9] It was found that in an orthopaedic surgical simulation, light cable ends were recorded
at a temperature of 213.8°F and subsequently could cause skin burns within a time
horizon of seconds. This result was supported in further studies.[10] To study the effects of light cable ends in a simulated OR, Smith and Roy employed
a study in which a 300-W light source was connected to a conventional fiber optic
cable and placed in various positions, in contact with standard surgical instruments
and items.[11] It was calculated that the fiber optic cable in contact with a surgical drape resulted
in a hole in the drape within 15 seconds.
To include viable patient-centered outcomes in this exploration, Spradling conducted
a comparable study utilizing cadavers as a conduit for examining skin damage due to
cables.[12] In this study, the temperature for cables was recorded at 382.1°F, surpassing that
of the previous study at the same unit of power. Contact with the fiber optic cable
resulted in skin damage to the cadaver, despite little visible change to the drape
covering the cadaver. No live or simulated patients were included in the previously
cited studies, therefore the limitations of these results are that the probability
of thermal damage was observed within the framework of the cable's ability to penetrate
protection of the simulated patient's skin, as opposed to measuring the impact to
the skin itself. Future studies may consider the inclusion of advanced skin models
as a vehicle for quantifying the specific time-dependent impact of incendiary cable
ends to the patient. The prior studies do, however, signify judgment on the hazards
of fiber optic light cables connected to a light source, by indicating that cable
ends can convey a serious burn threat in the OR, including cutaneous burns.[13] Fiber optics have been identified in a recent medical device safety report as one
of the top 10 technology safety hazards.[14]
Of the light sources, xenon light is most frequently associated with instances of
intraoperative burns. De Armendi et al detailed a pediatric patient who suffered a
second degree burn from a fiber optic xenon headlight utilized during a neck surgery
procedure.[15] In this case, the exact cause was deemed to be a lack of irrigation around the wound
site, combined with an incorrect proximate distance between the lens and the site
at maximum intensity. Retrospective analyses from this study were integrated into
the manufacturer manual to modify future use; however, such modifications are subject
to the discretion of each individual surgeon.
Burns are also cited in cases of overhead light use without effective heat shielding,
ranging in severity.[16]
[17]
[18] However, current light emitting diode (LED) technology can reduce heat emission.
Operating microscopes are detailed as the cause for significant burns in patients,
in large part due to the short working distances necessary in microsurgery. Schutt
et al describe the propensity for operative microscopes to impart thermal damage on
patients.[19] Operative microscopes were measured for irradiance at varying intensities, spot
sizes, and working distances. It was ascertained that microscopes have the potential
to transfer large amounts of energy to the patient, measuring as high as 736.26 J
absorbed by 1 cm2 of skin at a working distance of 20 cm over 200 minutes. These conclusions are corroborated
by the clinical literature. Choudhry et al reported a single case of a pediatric patient
whose brachial plexus palsy correction surgery resulted in a first degree burn from
an operating microscope.[20] Similarly, Al-Qattan and Clarke reported a case of a patient who experienced a burn
following brachial plexus reconstruction.[21] In response to published Food and Drug Administration (FDA) reports that listed
over 80 cases of tissue damage related to operating microscope burns, Latuska et al
conducted a retrospective case review in two tertiary academic centers.[22] This study unveiled four cases of microscope-related soft tissue burns during otologic
surgery. Boldrey et al supported these findings with the addition of 12 patients that
suffered macular and paramacular burns as a result of light overexposure in cataract
surgery.[23]
Preventive methods discussed with respect to operating microscopes encourage the utilization
of the lowest light intensity.[20] Yet, lowering the light intensity has the effect of reduced visualization for the
surgeon, which could contribute negatively to surgical performance. Others recommend
the adjustment of the aperture to align with the operative field.[22] However, illumination required in microsurgery presents a unique issue in that the
tissues being operated on are typically less than or equal to 3 mm in diameter. For
microsurgeries such as those detailed above, it is often infeasible to repeatedly
adjust the microscope when operating on relatively small geographic areas. Lastly,
the application of wet surgical sponges to the wound site can reduce the risk of burn.[22]
In response to the increased reporting of light-related burns, institutions such as
the FDA and the Japan Council for Quality Health Care have established registries
to collate episodes of patient burns as related to light sources.[24] However, these registries are voluntary and thus often under-report the total prevalence
of burns. Organizations such as the ECRI Institute have also produced guidelines for
the management of light sources in surgery to avoid burns, to little measured effect.[25]
There are multiple models as to how specific light sources may cause burns. The most
common source of burn results from maximum intensity and overexposure, which can be
controlled by selecting for lower intensity lights.[15]
[22] Other factors can increase the likelihood of burn. The patient's interaction with
certain anesthetic agents is found to reduce the skin's ability to dissipate heat
across the epidermis.[20] Choice of anesthesia can be controlled to some extent, but standard anesthetic agents
may not be feasibly removed from use. Other factors include the improper draping of
the patient, particularly around the wound site which receives the greatest amount
of light. Inadequate draping can lend itself to increasing the surface area that is
vulnerable to becoming overheated, thus increasing the burn risk.[15] A subsequent crucial factor for assessing burn risk relates to the aperture size
and distance from the illumination site, which varies considerably on a light source
basis. In general, it is cited that a greater distance between the light source and
wound site diminishes burn risk; however, this also reduces the surgeon's visibility
and is potentially detrimental to clinical performance.[9]
[19]
[20] In effect, the modifications required to mitigate the risk of burns associated with
conventional light sources are viable, but not often easily integrated into standardized
surgical procedures and may be slow to adopt from the practitioner perspective.
A French systematic review concluded that surgical fires caused by energy sources
comprised 11% of adverse events related to health care over 6 years, indicating a
significant driver for fire risk assessments in the OR.[26] In a cross-sectional study among members of the American Academy of Otolaryngology—Head
and Neck Surgery, the most frequent sources of ignition for reported fires included
electrosurgical units, lasers, and/or cable cords.[27] Furthermore, fiber optic light cables are broadly implicated in the “fire triangle”
of the OR, serving as the heat source element.[28]
Burns and fires, which are detrimental to patient safety as well as safety of all
OR physicians and staff, are thus presented as a significant environmental hazard,
particularly with regard to fiber optic light cables and light sources derived from
xenon bulbs.
Takeaways
-
Patient burns are recorded due to contact with fiber optic cables and/or light overexposure.
-
Fiber optic cables are subject to achieving dangerously high temperatures, recording
as high as 437°F within 10 minutes, and can result in a burn injury within seconds.
-
The ECRI Institute reports that 550 to 600 surgical fires occur annually.
Safety
Surgeon Health
Surgery presents a significant occupational health hazard. Surgeons must maintain
positions for an extended amount of time, deftly handling fine surgical instruments,
while often carrying the added physical weight of additional gear, such as protective
lead or even a surgical headlight. Specifically, regarding use of a headlight, surgeons
are thus placed at risk for developing musculoskeletal disorders (MSDs), including
cervical degenerative disk disease, which can thereby impair their ability to effectively
perform surgeries and can shorten their career. Several reports of MSDs in surgeons
are discussed, in addition to recommended interventions for reducing stressors on
the surgeon. Interventions emphasize moderating the surgeon's posture and removing
headlights and other additional weight where possible.
In recent years, the literature on physician health has expanded to hone in on the
epidemiology of MSDs among surgeons.[29]
[30]
[31] Dianat et al performed an analysis exploring the effect of the surgical profession
on prevalence of musculoskeletal symptoms.[32] It was explicated that musculoskeletal symptomatology was broadly prevalent among
recorded surgeons, specifically in the neck, shoulders, and low back regions, indicating
that these are areas of concern for occupational health. The noted effects were reasonably
mediated by the surgeon's schedule, including number and length of surgeries per week.
Cervical disk herniation is a specific musculoskeletal health issue reported in the
literature as deleterious to surgeon health. Tzeng et al reported a case series of
several surgeons who presented with magnetic resonance imaging-confirmed cervical
disk herniation.[33] A retrospective analysis of surgeon occupational history, combined with imaging,
confirmed that wearing surgical headlights and loupes was associated with symptom
onset. The surgeons in this study either sought physical therapy or underwent surgery
in severe cases following the analysis. All surgeons in the institution's department
were instructed to wear cervical braces during operations to mitigate risk of cervical
disk disease. Similarly, Sahni et al reported a single-site study that analyzed surgeon
occupational health by headlight exposure, finding that 68% of high-frequency headlight
users experienced aggravated neck symptoms as compared with 38% of non- or low-frequency
headlight users; additionally, 34% of high-frequency users developed confirmed clinical
diagnosis of degenerative cervical disorder compared with 7% of low-frequency users.[34] In a review, Fisher et al emphasized the importance of a healthy cervical spine
for optimizing surgical function.[35] He noted that the cervical spine is often manipulated during surgery to enact sustained
cervical hyperflexion for needed positions, rendering it vulnerable to overuse and
damage. Sustained musculoskeletal fatigue imparts significant long-term health effects,
thus impacting the surgeon's ability to perform future operations.[36]
The negative health effects of standing with stressors during surgery can cumulatively
result in significant health issues for the surgeon. Recommendations are in development
to improve the state of conditions for the surgeon. Rodigari found that surgeons who
accounted intense fatigue at time of standing during surgery had 16 times the risk
of developing musculoskeletal pain.[37] Rodigari recommended that the surgeon's working posture be controlled to minimize
stressors such as added weight, including the removal or minimization of headlight
use. In agreement, Esser et al recommended interventions to improve the ergonomics
of surgery, including lighting, table height, and surgical instruments as areas of
intervention.[3]
Takeaways
-
Physical stressors mitigate surgical performance at least once a month.
-
66% of surveyed surgeons reported having an occupational-related MSD.
-
A retrospective analysis of surgeon occupational history, combined with imaging, confirmed
that wearing surgical headlights was associated with symptom onset.
-
If left uncorrected, unergonomic surgical posture may result in cervical sprain and,
eventually, permanent disability.
-
A surgeon-directed, handheld light that does not rely on head or neck angle can be
effective in illuminating the surgical site without the physical consequences of other
lighting modalities.
Safety
Distractions
Distractions and interference occur often in the OR, spanning multiple surgical specialties.[38]
[39]
[40]
[41] There is emerging evidence to suggest that a direct relationship exists between
surgeon exposure to distractions in the OR and a decrease in patient safety.[42] Light-related distractions are often included in broader environmental or equipment
malfunction interruption categories, causing the examination of its effect on surgical
performance to be opaque. However, in recent years, the literature has expanded to
include light adjustments as a specific subcategory of OR distractions and interruptions.
Building off foundational texts, it is shown that light adjustments comprise a significant
portion of interruptions during surgery and may have quantifiable outcomes on surgical
performance as well as patient safety at large. Light sources thus represent an area
of opportunity to significantly minimize equipment-related distractions, thereby enhancing
patient safety and quality of care outcomes.
Distractions in the workplace can have long-lasting effects. Research cites that after
an interruption, it can take up to 23 minutes to recover in terms of concentration
and productivity.[43] The surgical theater is no different. In the OR, phone and/or pager calls are cited
to be the most frequent interruptions,[44]
[45]
[46]
[47]
[48]
[49]
[50]
[51] and subsequently are the greatest studied. Previous studies have exhibited the prevalence
of phone and pager calls as vehicles for distraction in the OR.[46] In light of this phenomenon, several studies have sought to examine the effect of
phone-based distractions on specific clinical performance. In a simulation study,
Yang compared simulated laparoscopic performance between surgeons who were exposed
to scheduled phone call distractions and a control cohort consisting of surgeons who
did not have distractions during the allotted time frame.[51] It was calculated that exposure to distractions was associated with worse surgical
performance, as measured by time to completion and accuracy of the task. Furthermore,
observed surgical and cognitive errors increased in the distraction cohort, emphasizing
that exposure to distractions has a cumulatively negative effect on surgical performance
over time.
The literature on lighting-specific distractions in the OR is limited but increasing.
In 2010, Knulst et al addressed the need for observing and quantifying luminaire actions,
so far lacking in the surgical literature.[2] In this study, the authors describe a method for observing OR staff during procedures,
including annotations by live observers as well as video recording. The function,
duration, and features of the luminaire action were noted as per a standardized rubric.
The luminaire actions were also mapped on a 3D rendering to ascertain if an adjustment
was made on the shortest route by distance. The authors subsequently released a questionnaire
to all participants, requesting information on the respondent's perception of SLS
as a whole. In this study, 56% of all lighting adjustments did not take the shortest
route to completion, thus increasing the time of adjustment. It was calculated that
on average, one light adjustment was noted to occur every 7.5 minutes. In 97% of the
cases, the performing surgeon paused his/her task to complete the lighting adjustment.
Moreover, the majority of lighting adjustments occurred during the time at which surgery
was performed at the wound site, suggesting that such adjustments had the potential
to viably affect specific time points in the surgery. This study demonstrated that
lighting adjustments are frequent during surgery, and significantly interrupt the
surgeon's actions during the operation. The findings were validated by surgeon questionnaires,
which affirmed that the lighting of deep wounds and shadows is a significant issue
during surgery. It has been suggested that a biometric study could yield further validation
of the impact of distractions.
Takeaways
-
Emerging evidence suggests that a direct relationship exists between surgeon exposure
to distractions in the OR and a decrease in patient safety.
-
63% of resident trainees made one unsafe clinical decision when distracted by cell
phone and/or pager interruptions.
-
After one interruption, it takes an individual on average 23 minutes to fully regain
his/her concentration to the task at hand.
-
One light adjustment occurs every 7.5 minutes in the OR and, therefore, is a potential
source of distraction.
-
In 97% of the cases, the surgeon paused his/her task to complete a lighting adjustment.
-
Equipment and OR environment distractions were found to be the greatest interference
factors affecting OR team function.
Disposables versus Reusables
Disposables versus Reusables
Reusable instruments, including lighted retractors and light cords, require a high
degree of decontamination and sterilization after use, to ensure that biological materials
from one patient do not come into contact with the next. Manufacturers often provide
manuals to inform sterilization processes for specific instruments, and hospitals
may have individual protocols in tandem. However, studies show that the decontamination
processes are not 100% effective, resulting in a significant proportion of instruments
that are culture-positive moving into the next procedure. Incomplete decontamination
has specific effects on patient's outcomes. A retrospective study showed that the
cause for a surgical site infection (SSI) epidemic in one facility was bacteria retained
by reusable surgical instruments. Further case studies of infection related to reusable
surgical instruments are also described. Disposable instruments offer a solution to
this issue, by ensuring complete and total sterilization. Comparative studies have
corroborated this statement, showing that surgeries performed with disposable instruments
result in a significantly decreased infection rate. Furthermore, specific studies
have combined a disposable piece, such as a sheath, with a reusable instrument and
concluded that optimal sterilization was achieved. Disposable instruments, and specifically
disposable additions to instruments, are thus shown to serve as an important tool
for achieving quality care and patient safety outcomes.
Cleanliness is at the core of surgical performance. The decontamination and sterilization
processes dictated for surgical instruments, including surgical lighting such as lighted
retractors, are established, yet not consistently adhered to.[52]
[53]
[54] Southworth conducted a comprehensive literature review, returning 21 cases of incomplete
decontamination.[54] Even when followed, the sterilization of reusable devices can be ineffective.[52] Kumar et al reported on steam, plasma, and ethyl oxidization routes of sterilization
for reusable instruments.[53] It was evaluated that an average of 5% of steam sterilized instruments and 3% of
plasma sterilization instruments failed the quality control indicators for effective
sterilization.
Infection caused by the transfer of bacteria can lead to less successful postoperative
patient outcomes. Infection Control Today highlighted a comparative study that examined the safety and efficacy of reusables
and disposables.[55] Following sterilization, 29.5% of samples from reusables devices tested bacteriologically
positive, of which the majority were pathogens. The FDA has also established MAUDE,
or Manufacturer and User Facility Device Experience, a central database that stores
reports of adverse events due to medical devices, including the improper decontamination
of reusable devices.[56] Tosh et al presented a case series of arthroscopic procedure patients who were exposed
to Pseudomonas aeruginosa and subsequently acquired SSIs.[57] In a retrospective analysis, it was revealed that the SSIs were likely related to
instrument reprocessing, as multiple surgical instruments were positive for P. aeruginosa. It was hypothesized that minor amounts of trace tissue retained in specific instruments
may have allowed an environment for the bacteria to outlast repeated sterilization.
Vijayaraghavan discuss an episode in their hospital in which a Mycobacterium chelonae outbreak was recorded in 35 patients who underwent laparoscopy over a period of 6
weeks.[58] In a study of portable medical equipment in the emergency department setting, Obasi
cultured the equipment after standard manual decontamination, to determine the efficacy
of the decontamination process.[59] In this study, 25% of the tested objects yielded culture-positive results, including
the presence of clinically significant microorganisms.
Disposables offer a solution to issues of contamination and sterility related to traditional
reusable instruments. It is shown that the implementation of disposable instruments
results in decreased infection rates postoperatively. Studies on lumbar fusion, total
knee arthroplasties have demonstrated significant reductions in infection rates when
switching to disposable instruments.[60]
[61]
Evidence for the use of specifically disposable additions to reusable instruments
is promising. Recognizing the intensive time and labor associated with processing
reusable endoscopic instruments, Alvarado et al introduced a transparent protective
sheath that did not markedly impair visualization for use on nasopharyngoscopes.[62] The instruments were tested for presence of bacteria via culture prior to the procedure,
immediately following the procedure with use of a sheath, and after an extensive sterilization
process which included an enzymatic rinse and ethanol disinfection. The number of
instruments with culture-confirmed bacteria decreased significantly following addition
of the sheath and was reduced to zero after the additional decontamination stage.
The study provided support for the use of disposable sheaths that can be applied to
instruments as a vehicle for contamination reduction initiatives. Indeed, such evidence
has produced policy changes abroad. In the United Kingdom, a significant increase
in variant Creutzfeldt-Jakob disease led the Department of Health to institute a mandatory
transition to universal disposable instruments in all surgical offices performing
adenotonsillectomy, with results pending.[63]
Incomplete decontamination and sterilization of reusable instruments represent a significant
clinical risk for patients. Disposables are proven to significantly decrease and/or
nullify pathogen growth or transfer among instruments, thus mitigating infection and
thereby improving postoperative outcomes for patients.
Takeaways
-
Even when followed, sterilization of reusable devices can be ineffective.
-
Following sterilization, 29.5% of reusable devices tested bacteriologically positive,
including pathogens.
-
In a 2-week period at one single institution, seven SSIs were caused by reusable surgical
instrument contamination.
-
In one institution, introduction of disposable instruments reduced the infection rate
by 66%, a statistically significant difference.[61]
Cost
Cost is a significant driver of Operations Management decisions. SLS (OR lights),
lighted retractor sets, and headlights each impose their own set of costs, including
purchase price and maintenance fees. In terms of reusable versus disposable surgical
instruments, the argument for cost is more nuanced than at first glance. The true
cost of reusable instruments includes not only the acquisition price, but also expenses
related to decontamination and sterilization, processing, transport, utilities, and
storage. In comparison, disposable instruments typically require a single predictable
expense. Several studies that conducted a ground-up cost analysis of reusable and
disposable instruments found that disposable instruments were more cost-effective
on a per-unit basis with all factors considered. In addition to the hidden costs of
reusable instruments, time in the OR is valued. Reusable instruments require set-up
and adjustment in the OR, whereas disposables require none. Time in the OR can be
expensive on a cost-per-minute basis; hence, saving time also saves costs incurred.
The literature suggests that a cost-effective supply chain for hospitals includes
disposable items where appropriate, and the optimization of time and space.
Of note, hospitals have limited resources, and thus may only own a specific, cost-limited
number of lighting systems—including OR lighting and portable systems. Therefore,
a hospital's OR schedule or clinical application may be limited by the supply of light
sources, rendering additional administrative challenges, including cost delays.
Current Illumination Methods
Current Illumination Methods
Overhead OR lights exist in every standard OR environment as a necessary minimum for
surgical illumination, and thus there is a baseline cost associated with these devices.
The SLS, commonly referred to as an OR light, is composed of two parts, the light
system itself and the surgical light handle utilized to adjust the direction and distance
of the light. The light configuration may be a single light or multiple light configuration,
all of which is attached to a suspension arm or arms tethered to the ceiling, wall,
or an external mobile shelf unit. Two types of lamp categories exist in OR lights:
conventional, or incandescent, and LED lamps. Incandescent lamps refer to a quartz,
xenon, or tungsten bulb that is filled with halogen, whereas LEDs are driven by electric
currents. Current price estimates list the purchase price for the light system at
$2,000 to $37,000 for incandescent lights, and $12,000 to $89,000 for LED lights.[a] The light system is typically sold separately from the light handle and the sterile
light handle covers. The light handles usually are priced at approximately $100 to
$150 for one aluminum handle, compared with $30 for one plastic handle. The sterile
light handle covers are sold in large quantities, typically 120 or more per package,
and are priced at approximately $200 for the total package, or about $1.50 to $3.00
per cover.
OR lights are typically high functioning for 3 to 10 years, depending on the warranty,
after which maintenance and repairs will require significant investment. Maintenance
and repairs of overhead lighting systems are usually serviced by a third-party vendor.
Surgical lighting technician rates sit at approximately $400/h for the first technician
hour, and $200/h for additional time, noninclusive of parts. Alternatively, hospitals
can arrange long-term contracts with technician vendors, which cost approximately
$5,000 to $6,000 per year and include semiannual and as needed technician visits.
In any case, replacement parts are sold separately, purchased either from the technician
vendor or directly from the manufacturer. Light system parts range in expense. Minute
hardware parts are in the cents and dollars range, but specific parts, such as master
controls, ceiling plate parts, and power supplies and electrical parts, can be several
hundred to thousands of dollars. In terms of the lamps themselves, replacement halogen
bulbs range from $10 to $100 per bulb depending on the specific features and are less
expensive in bulk. Replacement bulbs are typically not necessary for LEDs, given the
longevity of the source. Of note, halogen bulbs usually last 1,500 hours but can last
up to 4,000 hours, whereas LED bulbs usually last for 40,000 to 50,000 hours. Therefore,
the hospital's specific surgical load will dictate how often the light system is in
need of replacement bulbs. Again, however, the overhead OR lights are typically a
basic standard in OR suites, and their expense, in one range or another, cannot be
avoided.
Lighted retractor sets are a relatively recent addition to the field. Lighted retractors
broadly come in two forms, a standardized retractor that has a port for fiber optic
cable connection to a halogen or LED light source, and a cordless retractor with an
integrated, battery-powered LED light source. The associated costs for lighted retractor
sets are as follows: the standard reusable retractor ranges from $200 to $1,500 for
a single retractor, fiber optic cables range from $300 to $1,300 for a single cable
depending upon the length and port size, a sterilization tray is usually around $1,000,
and external light sources can range from $1,000 to $5,000 for LED, and $5,000 to
$20,000 for halogen. In total, a sophisticated system can cost more than $13,000 all
included. Furthermore, specific add-on pieces are available on a per case basis to
enhance illumination. These single use pieces may cost between $250 and $500. Lighted
retractors therefore can represent a significant expense on a per system basis, especially
with the understanding that if a single retractor system is being utilized in a surgery,
for example, it cannot be used elsewhere until it is fully decontaminated and sterilized
again.
Headlights can be advantageous, potentially reducing the need for multiple overhead
light adjustments. Headlights also minimize shadows, thus optimizing surgeon visibility.
However, headlights, as noted in the Surgeon Health (IIb) section above, can also
be disadvantageous. Surgical headlights are produced in a variety of light sources
and configurations. Light sources include halogen and LED sources. Configurations
range from the traditional, e.g., the headlight apparatus connected by fiber optic
cable to a light source, to more modern iterations. Headlights are also manufactured
as cordless, battery-operated, or rechargeable devices in an initiative to address
portability concerns. In terms of list price, the majority of headlights range from
approximately $1,000 to $10,000 per system depending upon the product specifications,
the sophistication of the system, and whether or not accessories are included. In
terms of maintenance, traditional standalone light sources range from $500 to $8,000
per system, and batteries required for newer headlight systems range from $100 to
$200 per unit.
Novel iterations of handheld lighting technologies provide a look into the future
of surgical illumination. Examples include a single cable system, which removes the
intermediary cable and directly connects a LED light source with an extended length,
disposable light source, and innovations such as sterile light strips that are adhesively
attached to the retractor and cabled to an adjacent light source. Sterilized, disposable
light strip products are typically sold in multiple-unit packages at a unit price
of approximately $100 per strip, not inclusive of the cable and light source itself.
A multitude of facilities may only possess one to two ancillary lighting systems at
one time, given the significant cost per unit, as stated prior. Moreover, the hospital
may also be limited in the number of portable light sources that are readily available.
This results in a limited supply of light sources for OR teams, given the length of
surgeries. Increased demand and limited resources may thus require hospitals to secure
loaner sets from another health care facility or third-party vendor, if necessary.
However, the loaner set process translates into its own set of challenges and expenses.
Administrators are needed to coordinate the loaner set process, which requires time
as well as additional compensated staff responsibilities. Furthermore, personnel must
be routed to complete the inventory, sterilization, and quality control processes
for the loaner set, incurring further costs. Solutions are needed to mitigate administrative
delays and ensure that surgeries can be performed with sufficient illumination using
ergonomically efficient solutions.
Sterilization and Decontamination
Sterilization and Decontamination
The cost of sterilization of an instrument tray includes the unit material cost as
well as labor. For reference, LaBove et al implemented a cost analysis of a plastic
and reconstructive office-based surgical suite, accounting for surgical supply, labor,
and administrative costs.[64] Subsequently, the data suggested that the estimated cost of sterilization in this
site, including sterilization supplies and labor, was an average of $94.28 per case.
Specific procedures of abdominoplasty, facelift, breast augmentation, and liposuction
were included in the average analysis. This result was validated by the conclusions
of Isaacson et al, who calculated the cost for reprocessing at $96.13 for reusable
flexible ureteroscopes.[65] Further estimates have calculated the comprehensive sterilization cost equates to
approximately $51 to $77 per tray.[66]
[67] Sterilization, including sterilization of light sources such as lighted retractors,
can therefore incur significant financial costs in terms of a hospital global budget,
particularly in cases of incomplete sterilization. In sum, the literature suggests
that the cost for reprocessing a single surgical instrument tray, inclusive of labor,
can range from $51 to $96, which is not an insignificant cost when factored into the
operations workflow management of a high-volume surgical center.
Given the data on sterilization, certain categories of disposable instruments are
shown in the literature to be more cost-effective for hospitals. Mager et al completed
a prospective clinical outcomes and cost study of procedures in a tertiary referral
center, comparing reusable to single-use flexible ureteroscopes.[68] The global cost analysis included the initial purchase, repair, and reprocessing
expenses for the reusable devices, compared with the acquisition price of disposable
instruments. It was concluded that the cost per procedure for reusable ureteroscopes
ranged from $1,212 to $1,743, depending upon the procedure. In contrast, in this institution,
the minimum price of a disposable ureteroscope was $1,300. The stated results reflected
a viable cost savings for the election of single-use instruments. In a parallel study,
Yang et al explored cost and performance for biopsy forceps in gastrointestinal endoscopies,
including purchase price as well as expenses for reprocessing.[69] It was calculated that the total cost per use for a single reusable forceps was
$58.06, while disposable forceps were each acquired at $38.00. Based on the cost analysis,
and comparable clinical outcomes, this institution elected to develop a strategy-driven
approach, wherein disposable forceps were preferred at a certain threshold of procedure
demand. In a study of fiberoptic flexible scopes for difficult tracheal intubation,
Aïssou calculated that the differential costs between reusable and disposable scopes
were minimal when acquisition, sterilization, and maintenance expenses were included,
€206 as compared with €200, respectively.[70] Based on these results, the authors indicated a preference for proceeding with single-use
devices. Cost equivalency and additional researched benefits of disposable devices
were cited as the basis for the decision.
Additional Considerations
Additional Considerations
Separate from the sterilization process, time in the OR is valued on a cost-per-minute
basis. Yu et al conducted a time-driven activity-based costing of pediatric appendectomies,
including consumable and labor costs.[71] The cost per minute in the OR was found to be $25.55 for this procedure. Similarly,
Childers and Maggard-Gibbons performed a review of hospitals in California, completing
analysis that the mean cost per minute of OR time was $37.45 for inpatient and $36.12
for ambulatory procedures.[72] In a study of New York health systems, Girotto et al concluded that the cost per
minute in the OR was between $60.00 and $100.00.[73] As evidenced above, any additional time in the OR is cost wasted, and elements such
as set-up time and time required to adjust, for example, fiber optic cable attachments
or overhead light handles, merely increases that cost, contributing to delays and
poor efficiency. A further expense to consider is that of storage allocation in the
hospital or surgical suite. Conventionally, reusable instruments are sterilized and
stored on-site when not in use.
Takeaways
-
Acquisition cost of ancillary surgical lighting can be expensive, with a purchase
price of up to $10,000 to $13,000 for advanced headlights and lighted retractor systems.
-
Maintenance and repair costs are often overlooked, and average $5,500 per year for
technician time, and can cost up to $1,000 per year in replacement parts depending
on the specific part.
-
Sterilization and processing costs for reusable instruments are additional real costs
and are estimated at $50 to $100 per tray.
-
The average cost per minute in the OR can be up to $100 per minute, not including
the surgeon's cost, so efficiency and time savings can result in an increase in facility
profitability.
-
There is further value to optimizing shelf and storage space, by minimizing additional
costs.
Conclusion
The evolution of surgical illumination continues to be addressed through research
and practice. However, the literature lends itself to providing a framework for assessing
the needs of surgeons with respect to surgical illumination. Three components of surgical
lights are essential: a light source should (1) center on the surgeon's immediate
field, (2) illuminate with high-intensity light, and (3) viably penetrate into surgical
cavities or under flaps. Each of the current OR lighting methods meets at least one
of these criteria, but none meets all, thus leaving room for a novel product to enter
the space.
Researchers and surgeons alike contend several issues with conventional light sources.
Burns and fires represent a significant risk of current lighting systems. Surgical
lighting, most frequently fiber optic cables from lighted retractors, are directly
responsible for severe burn damage to patients, as recorded by the U.S. FDA. Patients
have suffered second and third degree burns as a result of current lighting options.
Light sources are also implicated in a great proportion of surgical fires, which serves
as an environmental hazard for patients, surgeons, and all OR and hospital staff.
In line with safety and workflow concerns, current lighting systems take their toll
on surgeons with respect to physical and cognitive health. Headlights specifically
impart ergonomic issues, in large part due to the weight and need for movement-driven
adjustment. Studies have reported that frequent headlight use is an occupational health
hazard with specific negative health outcomes and may even be linked to the shortening
of a surgeon's career. More broadly, current lighting systems are associated with
multiple levels of adjustment, from moving surgical light handles to the alteration
of cables for lighted retractors. Aside from data which reveal that even previously
sterile OR light handles harbor bacteria, and the extrapolation that repeated manipulation
can result in transfer to surgical gloves, such distractions have a marked effect
on surgeon performance, with experts citing that a 1-minute distraction may result
in a 23-minute delay in cognitive processing and focus. Distractions could lead to
negative outcomes with respect to patient safety and quality of care. Future biometric
studies may explore in-depth impact of specific distractions on surgeon's performance
and OR ergonomics, providing a research tool to support use of future OR technologies.
On another note, time also has measurable outcomes on global cost to the hospital.
Cost-per-minute in the OR varies from hospital to hospital as well as regionally but
can be as high as $100. Given that each adjustment of a lighting system can take minutes,
multiplied by the total number of adjustments per surgery, it logically follows that
cost associated with light-related distractions may represent an unnecessary expense
to the hospital.
With respect to future surgical illumination sources, it is debated whether reusable
or disposable options are most advantageous. This can be considered from the sterility
and cost perspectives. With respect to decontamination and sterilization, disposable
instruments can be more effective than reusable instruments. Multiple cases of measured
nonsterilization are reported with reusable instruments, with marked effects including
SSIs. In addition, in many cases, when all hidden costs are factored in, it is found
that disposable devices are, in fact, often less expensive on a per-unit basis, strengthening
the support for single-use instruments, including lighting devices.
