INSIDE THE CURRENT ISSUE

October 2012

Operating Room

Outpatient Connection
ICU misdiagnoses may account for as many annual deaths as breast cancer

Each year as many as 40,500 critically ill U.S. hospital patients die with an unknown medical condition that may have caused or contributed to their death, Johns Hopkins patient safety experts report in a recent study.

In a discussion of their findings, described online in BMJ Quality & Safety, researchers say that although diagnostic errors in the intensive care unit (ICU) may claim as many lives each year as breast cancer, they remain an underappreciated cause of preventable patient harm.

"Our study shows that misdiagnosis is alarmingly common in the acute care setting," says Bradford Winters, M.D., Ph.D., lead author and associate professor of anesthesiology and critical care medicine and neurology and surgery in the Johns Hopkins University School of Medicine.

By reviewing studies that used autopsy to detect diagnostic errors in adult ICU patients, the experts in the Johns Hopkins Armstrong Institute for Patient Safety and Quality discovered that 28 percent of patients — more than one in four — had at least one missed diagnosis at death. In 8 percent of patients, the diagnostic error was serious enough that it may either have caused or directly contributed to the individual’s death and, if known, likely would have changed treatment, researchers say. Infections and vascular maladies, such as heart attack and stroke, accounted for more than three-quarters of those fatal flaws.

Overall, the medical conditions most commonly missed by diagnosticians included heart attack; pulmonary embolism, an artery blockage in the lungs; pneumonia; and aspergillosis, a fungal infection that most commonly affects individuals with a weakened immune system. Cumulatively, these four conditions accounted for about one-third of all illnesses that doctors failed to detect.

After collecting and classifying all error data, the researchers calculated how frequently misdiagnoses would be discovered if every patient who died in the ICU underwent an autopsy. Although autopsy is more frequently performed in complex patient cases in which the clinician may have a lower level of diagnostic certainty, the authors took this potential bias into account. Based on those adjustments, they say their calculations are conservative estimates.

"We need to develop better cognitive tools that can take into account the 7,000 or more pieces of information that critical care physicians are bombarded with each day to ensure we’re not ruling out potential diagnoses," Winters says.

Although two-thirds of discovered misdiagnoses did not directly contribute to the patient’s death, Winters says they’re an important indicator of accuracy and aren’t without costs. Patients may endure lengthened hospital stays, unnecessary surgical procedures and reduced quality of life because of non-fatal diagnostic mistakes, Winters adds.

 

High-tech surgical suites pursuing high-def tools

BERCHTOLD surgical display installation
at St. Thomas Hospital, Nashville, TN

by Jeannie Akridge

With the advent of high-definition television, consumers can now enjoy movie-theater like picture quality in the comfort of their home. Most buyers look for large screen sizes and clear, sharp images as primary selling points. When it comes to HD displays that are used in the operating room, screen size and high-resolution image quality are equally, arguably more important. However, some key distinctions exist that make shopping for an HD surgical monitor vastly different from buying an HDTV for the home.

Jake Isley, product manager, CHROMOPHARE, BERCHTOLD, observed that compared to the typical shopping experience for an HDTV for the home setting where there may be a choice of 50 or 60 different models hanging in the retail showroom, stringent FDA regulations greatly narrow the available options that can be placed in a surgical suite.

"While an HDTV for your home may look similar to a high-definition surgical display (also referred to as a monitor) designed for the operating room, these products are actually quite different from each other, as is their procurement method," said Jim Roselius, Vision Systems group manager, Panasonic System Communications Company of North America. "Healthcare customers often work with resellers to purchase professional grade surgical displays which are typically sold through the channel."

Anne Bondulich, marketing manager, surgical products, Sony Medical, commented, "Whether you’re shopping for an HD surgical display or an HDTV for the home you’ll want to compare brand features, specifications, size, and price. However, the process of selecting a surgical display for the OR is quite different than an HDTV for the living room. For surgical displays, look for medical grade certification which is often required in the OR especially for use close to the sterile field. Medical grade monitors generally are more ruggedized, comply with medical safety regulations, meet higher electrical standards, and are designed to be wiped clean for sanitary conditions. These displays are also VESA compliant and can be either boom arm-mounted or wall-mounted. You should also compare specifications such as resolution, aspect ratio, and signal inputs/outputs of your camera system with those of the monitor to ensure operability and optimum image quality."       

Screen sizes of up to 56 inches are not uncommon in today’s hybrid OR environment, Isley noted. At the same time, a slim profile is key in the space-constrained OR. With some monitors weighing up to 150 pounds, it’s essential to verify that the flat panel arms will hold the monitor steady without drifting over time — while still allowing flexibility to maneuver into a variety of positions. The mounting pattern on the back of the monitor should also be considered, with a "VESA" pattern being the most common and typically easiest to mount, said Isley.

Roselius emphasized differences in professional services and warranties. "Consumer displays usually come with a 1-year warranty which is voided if the device is used in a commercial capacity. Professional displays however, often come with a standard 2-year warranty and an option for an additional 3 to 5-year extended warranty. When the healthcare customer is ready to make their purchase decision they will work with a reseller to make their purchase through the channel. The channel is incredibly valuable as it fills the gap between customer needs and what the business can supply. Resellers can assist customers with installation and deployment services, technical and sales support issues."

26" monitor from STERIS Surgical Solutions

"Selecting a surgical monitor is very different from shopping for a home theater system," contended Melissa Sminchak, associate product manager, STERIS Surgical Solutions. "Our surgical-grade monitors are designed for the OR environment, and are built to last. For example, there are no vents, fans, or molded plastic design elements that could temporarily trap airborne particulates, which minimizes the risk of infection for surgical patients. In contrast, some theater systems are designed for aesthetics and low manufacturing cost, and dust is not a critical concern for them."

"In addition, HDTV for the home environment only needs to accommodate a small number of signal inputs and resolutions," she said. "A surgical display must accommodate a much wider array of resolutions and signal types. Healthcare providers should assure that the surgical displays they select are compatible with all the equipment currently in use, and that their integration systems can accommodate future technology."

Herb Ruterschmidt, product manager, TRU-Vu Monitors Inc., advised: "A consumer shopping for a HDTV for personal use will typically select a TV based upon price, screen size (the largest he can afford) and brand name. The selection process for a HD surgical display will include some of these same criteria, but to a lesser degree. A surgical-grade display must be selected for optimal image quality, true color reproduction, long-term reliability, include the feature set necessary for the particular installation, a medical-grade power supply and green-dot power cord, and must of course carry the proper agency certifications and approvals." Ease of cleaning will also be a factor, he noted. "The new zero-bezel designs are becoming increasingly popular." Zero-bezel, he explained, means the glass on the front of the monitor goes from edge to edge, with no metal frame on the front side. A single, seamless piece of glass covers the entire front face, giving the monitor a sleek, modern look, and a glossy finish. More importantly for the healthcare environment, the bezel-less design eliminates the potential for contamination build-up under the bezel and the solid surface makes it easy to clean.

"When purchasing a display for a ‘mission critical’ surgical application a number of additional factors must be considered versus when purchasing a home TV," said Andy Larg, director of marketing, NDS Surgical Imaging. "Since patient safety and hospital liability are at stake, it is important that the highest quality product is selected. The manufacturer should be an ISO certified, FDA registered company with a quality system fully compliant with rigorous certifications demanded by region-specific regulatory organizations including FDA, Health Canada, Japan PAL, China SFDA, and Notify Body (Europe)."

"Confirming that the display meets medical industry standards is essential, when it comes to sanitization and industry equipment standards," Roselius stated. "Surgical displays should be FDA Class 1 and UL60601 certified. UL60601 certification is the standard for medical electrical equipment recognized by public health authorities in most countries. IPX1Protection rating is also instrumental in a professional grade display and choosing one with an antimicrobial surface will make it easy to clean and sanitize. Installing devices that don’t meet the appropriate industry specifications could create liabilities from a performance and legal standpoint."

NDSsi 26" Radiance G2 HB with surgical and vitals split-screen

How colors are displayed is another key distinction for a surgical monitor. "The color performance and consistency from display to display is important since clinicians may use these devices as means of making diagnostic decisions based upon the color tone of tissues," said Larg, NDSsi. "Many consumer displays are tuned toward the red spectrum in an effort to warm the fleshtones of on-camera talent and please consumer tastes; others are tuned for extreme contrast to make movie watching more dramatic. Obviously, this would be unacceptable for medical-grade usage. High-quality surgical displays are carefully calibrated to produce a true representation of color."

"Purchasing a display that is proven to be compatible with various medical imaging devices is critical, since many imaging devices do not follow video standards and often use proprietary video formats," he added. "Purchasing a display that can quickly and easily be disinfected is important to ensure quick OR turn-around times. OR cost is rated in dollars per minute – at home you have all day to clean your display."

Surgical display specs

Vendors provided additional details as to specifications to consider when purchasing medical grade surgical monitors, with special attention to image quality and resolution.

"When choosing a wide-screen display consider full capability 1920 x 1080 resolution which is quickly becoming the standard for most endoscopic camera systems," said Bondulich, Sony. "You will also want to choose a monitor that more closely matches the aspect ratio of the images that are captured by the endoscopic camera system. For example, some systems require either a 4:3, 5:4, 16:9, or 16:10 monitor aspect ratio to perform at their optimum level."    

Sony OLED Medical Monit

"Many of our displays feature Sony’s exclusive ChromaTRU color processing technology which ensures precise color matching between multiple monitors," said Bondulich of the company’s medical-grade compliant surgical flat panel displays. "ChromaTRU color precisely calibrates each LCD panel’s light output so that the RGB color coordinates are consistent for every monitor. A second calibration is further applied so that the white balance is maintained at a consistent color temperature. This technology is invaluable for applications such as simultaneous monitoring in operating rooms."

"Our monitors also feature a sophisticated advanced I/P (interlace to progressive) conversion," she said. "I/P conversion is essential, enabling an interlaced video signal to display on the LCD progressive panel. Our displays incorporate a variety of multiple display modes such as Mirror Image, Picture-in-Picture, and Side-by-Side for flexible multi-image viewing. Sony surgical displays can also accept a wide variety of input and output signals for integration into virtually any system environment."   

Sony’s 3D/2D 24" (measured diagonally) medical grade monitor "is outstanding for viewing 3D images captured by today’s state-of-the-art endoscopic and microsurgery camera systems," said Bondulich. "The monitor is 2D/3D switchable and may be used with both 2D and 3D camera systems, which makes it ideal for surgeons planning to upgrade to 3D technology in the future. 3D imaging provides a truer visual experience, closer to natural sight, than 2D imaging. It improves depth perception and spatial orientation and as a result can help surgeons more easily grasp, cut, and suture tissue." 

She described the latest advancement from Sony offering a unique platform for consideration. "OLED (Organic Light-Emitting Diode) is the newest groundbreaking technology offered by Sony that features exceptional image quality that outperforms LCD (Liquid Crystal Display). OLED is made from organic materials that react to electric current to output light. Combined with Sony’s ‘Super Top Emission’ structure and exclusive TRIMASTER EL technology, OLED provides accurate color reproduction even in deep dark areas, the widest color gamut of any Sony monitor previously offered, response time more than 10X faster than LCD for virtually no motion blur, and accurate black detail reproduction. The Sony PVM-2551MD, 25" is the world’s first medical-grade [OLED] monitor to be offered."

TRU-Vu Monitor

Ruterschmidt,TRU-Vu, advised," Ideally, the native resolution of the monitor should be the same as the incoming video signal."

TRU-Vu’s 22" Medical-Grade LCD wide­screen (16:10 aspect ratio) 720p HD color monitor (MM-22C) provides an ultra-wide 178º x 178º viewing angle, quick response time, and brilliant color reproduction. With both digital and analog video inputs and rear 100 x 100 mm VESA mounting hole pattern, the MM-22C offers versatility in connectivity as well as mounting. The new TRU-Vu MMTR-22C wide-screen 22" HD medical touch screen is a high-brightness, high resolution monitor that delivers excellent image quality and color contrast. The monitors include TRU-Vu’s full 3-year warranty.

Roselius noted the importance of a wide viewing angle to allow staff the ability to view images displayed from top, bottom, left and right angles. "Having such a clear view of the screen is valuable in the OR where space is usually limited and staff cannot always position themselves to face a medical monitor directly."

"Being able to see multiple images at once such as vital signs, the surgical procedure itself, and radiological images is also incredibly useful in a surgical environment as it helps to reduce clutter," he continued. "To be able to view multiple images you’ll need to make sure there are multiple inputs on the professional grade display you select. There are even options when it comes to the dimensions of the images you are viewing. Today there are not only 2D medical grade monitors on the market but also 3D monitors that can alternatively provide excellent 2D image quality."

Panasonic EJ-MDA32U

Describing options from Panasonic, Roselius noted, "We have a family of full HD medical grade monitors with sharp color and stereoscopic features that actually surpass medical electrical equipment sanitization and industry standards. With our IPS-Pro technology, users can view natural full HD images from a wide selection of angles. IPS-Pro also reproduces vibrant color and perspective with enough depth to give the perception of 3D depth for surgeons and OR staff."

The EJ-MDA32U series of professional grade monitors also produces HD images with over 2 million pixels and a 1200:1 contrast ratio, "delivering the brilliant image quality needed in surgical settings," he said, noting the line’s "exceptional color reproduction and user-friendly technology that can even reduce surgeons’ eye fatigue when viewing content."

The EJ-MDA32U allows for up to three images, from three separate sources, to be displayed simultaneously, on one screen as the monitors have multiple outputs. The monitor supports two HD-SDI inputs, two DVI inputs and an analog input. "This allows for live viewing of the surgery, radiological images and vital signs on a single display," said Roselius.

Panasonic’s EJ-MDA32U-K 32" medical-grade 3D monitor provides exceptional image quality in both 2D and 3D, he offered. "The new 3D monitor uses the Xpol circular polarizing system to produce its 3D image instead of the usual linear polarization solutions. Panasonic’s passive circular polarizing glasses and the Xpol system maintain the stereoscopic effect even when the head is tilted to the left or right – a benefit linear polarization solutions cannot offer. This feature allows for a natural viewing experience and several clinicians or medical students in the OR to watch the same 3D display. The device also supports multiple 3D formats and inputs."

"Before comparing product options and specs," added Roselius, "we recommend first understanding exactly which features OR surgeons and nurses need the most; Is it vital that your surgeons are able to view the monitor from a wide angle? Would the surgical staff prefer 3D viewing, or at least want that option in the future? How much space do you have for a display in the surgical bubble? These are the questions you should ask hospital staff before making your investment."

"The quality of the image remains the most important aspect of a surgical monitor," agreed Sminchak, STERIS, "However, other factors that should be considered include the monitor’s durability, resolution, readiness for future technology the department may acquire, and compatibility with the endoscopes being used in the facility. Buyers should be asking questions such as: Will my monitor work with my other technology? What video input signals will my monitor broadcast? Is this monitor safe in the vicinity of my patient?"

"STERIS monitors provide superior color and consistent image quality, every time, Sminchak touted. "Our surgical-grade monitors include broadcast-quality electronics. [They] do not have vents that could harbor dust particles, or fans that might interfere with laminar flow or send debris over the sterile field. They are lightweight and have sturdy aluminum cases and an optical quality polycarbonate cover over the display area. The cable management system neatly routes video, power and control cables behind a protective cover that is easy to clean."

Larg noted that it’s important that output luminance, or brightness, "be relatively high to ensure the image can easily be viewed in high ambient light conditions (such as under surgical lights). Response time is important to ensure that fast moving images are crisply displayed and do not appear blurry or smeared. Video input capabilities are of key importance since they are what determine what types of imaging devices can be connected to the display. For example, in order to view the high resolution video output of most C-arm fluoroscopy machines, the display must have a special SOG (sync-on-green) single BNC input connection."

NDSsi’s 26" Radiance G2 HB surgical display offers high-bright LED backlight technology, Larg described. Exclusive to NDS, the technology offers 800 nits max., 500 nits calibrated. An Intelli-guard backlight stabilization system regulates the backlight to maintain a calibrated luminance output of 500 nits by slowly increasing the backlight drive level as the display ages. All NDS Radiance G2 displays include Color Correction Technology that ensures precise consistency and allows the display to meet the BT.709 HDTV color standard. Input options include 2 x DVI inputs, 2 x 3G-SDI inputs, 2 x SOG inputs, or optional single-fiber optic input. A video level setting allows the display to "expand" the dynamic range of signals such as SDI, to provide darker black levels and brighter white levels.

Achieving true HD

While choosing a high-quality HD surgical display is the first step to achieving optimal image quality, the way the monitor is integrated with the input source as well as the type of conduit, or wireless, system used will ultimately determine the clarity of what the surgeon sees on the screen. In order to maximize investment in HD monitors, and ensure surgeons are presented with the sharpest images, requires a three-pronged approach encompassing all of the links in the chain, from the input source, i.e., the camera or endoscope capturing the image, to the conduit or cabling (ideally fiber optic), to the output source, i.e., the monitor/display, Isley illustrated, emphasizing that any weak link will compromise the goal of achieving true HD 1080p resolution.

Berchtold’s ChromoVision HD Wireless in-light camera solution allows images to be routed from the camera to the destination monitor while continuously maintaining the native integrity of the HD signal. With a conventional wired system, "there is potential for signal degradation due to wire crimping within the mounting systems," said Isley. Also "up conversion affects image quality," he cautioned. "We’ve eliminated the step of needing to convert the image, so that there is no signal loss or degradation."

Larg advised: "To ensure the integrity of HD signals is maintained from the source equipment all the way through the imaging chain to the display, several principals and guidelines need to be followed. The video signal should never be down-scaled to a lower-resolution as this will dramatically impact the image quality. Conversion of video signals from digital to analog formats should be avoided. If done properly, conversion of analog signals to a digital format such as DVI or SDI will not result in any loss of quality, provided the signal’s resolution is maintained. Integration systems that convert all input signals to one digital format have significant advantages both in terms of cabling simplicity, as well as preservation of image quality."

NDSsi’s customizable ConductOR enables routing of virtually any medical imaging source to the surgeon’s field of view and beyond, Larg described. Serving as the visualization informatics backbone for integrated ORs used for minimally-invasive surgery, "ConductOR can replace an entire rack of older A/V equipment," he said.

NDSsi’s ScaleOR is a medical-grade video scaling appliance that provides flexibility to choose the appropriate input module to accommodate analog or digital signal conversions and scaling. ZeroWire HD Wireless Imaging delivers full HD surgical video in real time with less than 1-frame latency. It utilizes the Ultra-Wideband (UWB) frequency spectrum, allowing it to co-exist with other electronic devices in the OR, Larg explained.

The choice of camera system also plays a role in attaining true HD quality images in the surgical suite, said Bondulich. "The most important factor in ensuring the highest quality in an integrated OR suite is to choose a surgical camera system that produces the highest definition video and best image quality. In fact, many of the best quality surgical camera systems on the market today incorporate Sony sensor, camera module and digital signal processing technology as the core technology. Sony monitors are precision instruments designed to accurately display the full quality of the captured image, ensuring optimal video and still image clarity from the surgical camera system. Sony surgical displays offer a broad variety of input capabilities compatibility with virtually all surgical camera systems. Unique image enhancement and color control features such as ChromaTru also contribute to providing the highest quality HD video in the OR. Additionally, Sony offers recorders, printers and storage solutions that preserve the highest HD quality throughout the entire surgical imaging workflow."    

Sminchak noted, "Our Harmony iQ integration systems are not only compatible with all major endoscopic cameras and other sources of video; they also have a 1080p end-to-end digital fiber backbone infrastructure. STERIS uses broadcast quality electronics and specifically designs components for use in the OR. This combination ensures minimal lag and motion blur for surgeons, and helps prevent the stress and frustration than can result from a noticeable delay between actual hand movement and the resulting video display. The STERIS system with fiber optics has the greatest available ‘bandwidth’ so that all the video information coming into the system is displayed on the other end."

"The Harmony LED pre-wired extension arms use a patented technology that protects the internal wiring and prevents cable damage," she added. Also, "encasing our fiber optic cables in a double–wall Kevlar* jacket prevents them from kinking and breaking."

Panasonic’s line of medical-grade HD quality monitors and displays, HD remote head cameras and recording devices, "create an HD ecosystem for the surgical environment and can help hospitals fully digitally integrate their OR suites," said Roselius.

*Kevlar is a registered trademark of DuPont.