April 28, 2021

Numerous patient safety risks can be mitigated by careful positioning and proper application of safeguards.

DEFY GRAVITY Patients in steep Trendelenburg face numerous dangerous physical stressors that require careful monitoring and mitigation by the OR staff.

As the popularity of robotic urologic and gynecological procedures increases, so is the need to put patients in the gravity-defying, slide-inducing steep version of the Trendelenburg position. That creates patient safety challenges for your OR staff, because if executed improperly, this position can lead to skin tears, pressure injuries and other complications.

Emma Greene, BSN, RN, CNOR, a nurse at Northside Hospital in Atlanta, says safety risks increase with the steepness of the angle and the duration of the procedure. The literal gravity of the situation not only can cause the patient to slide down the table's surface and possibly tear skin along the way, but also increases intraocular and intracranial pressures as well as risks of airway and facial edema.

"I've seen a few patients emerge from anesthesia with significant swelling around the eyes," says Ms. Greene. "In one case, we had to keep the patient intubated to let the swelling go down. If a procedure is taking longer than three hours, consider flattening the patient out for a few minutes to give their body a break."

Particularly challenging is the lithotomy-Trendelenburg position — supine with legs separated, flexed and supported in stirrups. This position, which compresses the lateral side of the legs, can lead to injuries of peroneal, obturator, sciatic and popliteal nerves. Ms. Green says surgeons at her facility often employ this position for robotic prostatectomies, and she stresses the importance rooting out any inconsistencies, no matter how minor, in low lithotomy positioning. Her suggestions:

• Ensure the table is properly positioned and securely attach a non-slip positioning pad to its surface.
• Align the hips and buttocks with the cutout in the surface.
• After intubation, slowly and simultaneously place the legs in stirrups. "Limit pressure on the back of the knees and make sure the heels are at the back of the stirrups, the knees are lined up with the opposite shoulder, hips are not over-rotated externally and all pressure points are padded," says Ms. Greene.
• Pad IV locations and securely wrap the patient's arms, covering the elbow to prevent ulnar nerve injury and the hands to prevent crushing or pinching injuries when raising or lowering the stirrups.
• Place the patient's arms at their sides with thumbs up and palms facing inward.
• Draw the sheet up and over the arms, making sure to support the elbow, and tuck it under their body, using the patient's weight to secure the sheet; don't just stuff it under the table pad.
• If you use a chest strap to secure the patient, be aware that it can compress the area where gravity is already pushing the abdominal cavity toward the lungs.
• Pad the patient's head, making sure it is properly aligned and the face is protected. "We place a foam donut under the head, which provides better non-slip friction than a regular pillow," says Ms. Greene.
• When the patient is fully positioned, run through a checklist of potential problem areas. Are the patient's legs aligned and positioned correctly in the stirrups? Are all sensitive areas sufficiently padded? Are the arms secured at their sides? Is the patient secure on the surface after the table has been tilted?

"Adding extra safeguards and standardizing your Trendelenburg protocols is well worth the effort," says Ms. Greene. "The last thing you want for a patient who trusts you to perform a complex surgery is to send them home with a positioning-related complication."

Minimally invasive procedures become less dangerous when active warming is applied.

Credit: Cedric J. Ortiguera, MD
OR teams performing robotic surgeries should not let their guard down about maintaining the patient’s normothermia.

The relationship between robotic surgery and inadvertent perioperative hypothermia is the subject of increased investigation. Minimally invasive robotic surgeries were assumed to provide less risk of losing normothermia than traditional open surgeries, but that assumption has been called into question. A recent case study examined the relationship in the specific subspecialty of pediatric robotic pyeloplasty, which requires placing patients in the left lateral and steep Trendelenburg position.

According to the study, published last June in the Journal of Neonatology & Clinical Pediatrics, a seven-year-old male patient presented for robotic pyeloplasty. The patient was pre-medicated with midazolam, fentanyl and glycopyrrolate, induced with propofol and maintained on low flow (1L/min) nitrous oxide, oxygen, sevoflurane (2%) with volume control ventilation (VCV). Pneumoperitoneum was created and maintained below 12mm Hg.

After the patient was positioned in left lateral and steep Trendelenburg position, end tidal carbon dioxide (EtCO2) unexpectedly rose to a dangerous level of 45 to 55 mmHg. Changes to ventilator settings did not alleviate the situation, while peak inspiratory pressure (PIP) and plateau pressure rose to 32mm Hg and 28mm Hg, respectively. The patient was shifted onto pressure-controlled, lung-protective ventilation, which lowered EtCO2 to the range of 40 to 45mmHg.

After the 4.5-hour surgery, the patient was not taking spontaneous breaths despite an hour passing since the last dose of relaxant and no signs of hypercapnia, as EtCO2 was within 35 to 40mm Hg. The patient's axillary temperature was 36°C. Ventilation continued, and the patient was actively warmed for 30 minutes, as the team theorized that hypothermia was behind the delayed awakening. After active warming, the patient was finally successfully extubated and shifted to the PACU.

The team regrouped to determine exactly what caused the delayed awakening and hypothermia. They ruled out hypoglycemia, hypoxia, hypercapnia, electrolyte disturbances and drug overdoses. Although the IV and irrigation fluids were warm and the patient was properly covered with warm sheets, they concluded that the long duration of surgery resulted in prolonged exposure to the cold, dry insufflating carbon dioxide used during laparoscopy, which led to core hypothermia. They also cited research found exaggerated instances of intraoperative hypothermia in the head-down position.

"When dealing with pediatric patients or surgeries demanding accurate temperature monitoring, due caution [should] be paid to the relationship between the measured temperature and the core temperature," say the researchers. "This can guide us in an accurate assessment and efficient prevention of hypothermia."

The preventive measures recommended by the researchers include active warming devices and heat humidifiers. Insufflating gas flows should be warmed and kept below 2 L/min, while a surgical humidification system should be used to humidify and warm the gas to about 37°C, they suggest.

"There are various critical anesthetic concerns in robotic-assisted pediatric surgery," says the team. "However, with meticulous preparation, close watch of the functional correlations, active efforts and good communication, complications can be minimized to achieve improved patient outcomes."

A robotics expert choses safe securement that also offers warming.

Credit: Augustine Surgical Inc
WaffleGrip™ is a disposable, friction-based surface that safely prevents sliding in Steep T while also effectively transferring heat from HotDog® Patient Warming. Information and videos at: https://hotdogwarming.com/wafflegrip-trendelenburg-positioner/

Eleanor Markle, RN, CNOR is currently a consultant specializing in robotic program growth and development. She has worked in the Las Vegas robotic market for the past 12 years for multiple organizations, has been a guest speaker for Intuitive Surgical Inc. and a consultant for Augustine Surgical, Inc., and has taught robotic excellence courses across the country. She believes every patient deserves the best minimally invasive procedure available and is passionate about driving robotic excellence. She shares her insights about how to achieve the best patient experience.

Q: In your previous roles as robotic coordinator, you spent years looking for the best securement solution. Tell us what you were looking for to fill that need.
With robotics, safety is always the first consideration. I'm always looking for positioning equipment that first will be safe for patients. Then, it has to be efficient – quick and easy to use. Anesthesia must buy in, and the cost needs to be reasonable.

To avoid re-docking the robot, the patient must be perfectly stabilized. That is obviously Number 1, but it is not the only issue. You have to consider turn-over time; every minute on a robot is expensive. With heavy patients, staff safety during transfer can be an issue. Then there's warming to consider, since normothermic patients have the best outcomes. Justifying the expense of robotic surgery demands better outcomes.

Q: What did you try initially?
Pink foam roll was first, but the way our patients received an epidural, relaxing them completely, created dead weight. With foam, it's very difficult to reposition the patient. Foam requires storage space and creates lots of waste. Securing to the bed is problematic. Warming from below is impossible.

Next, we tried gel pads, but we had trouble with the integrity of the pads and worried about body weight shifting, creating micro shear forces and pressure injuries. I was concerned about infections as well as pressure injuries. Warming was still an issue.

Then we tried a mechanical device with a frame and a foam safety bump at the neck and shoulder bolsters, but I couldn't get 100% of my anesthesia providers to get onboard. To run an efficient robotic program, you really want to standardize as much as possible, including positioning. The anesthesia providers didn't like the mechanical device because of brachial-plexus injury concerns, no matter what information and training I tried to provide for them. I also found a group of our larger patients with neck and upper back anatomy that didn't allow for the safety bump to work, causing some concern about workarounds to secure those patients.

Q: You ultimately chose WaffleGrip as a solution. Why?
In an effort to continue to standardize positioning, I trialed WaffleGrip with a group of anesthesia providers who had refused to use the mechanical device. They loved WaffleGrip. It is easy to use, easy to reposition, easy to educate staff and physicians on, and the warming was an additional benefit. Rolling out for the whole program was easy after that. What I found next was that our non-robotic teams were adopting WaffleGrip for nonrobotic cases as a best practice for lap GYN and lap colon cases. Over time we expanded our use outside of robotic to our laparoscopic cases.

Q: Was there a concern for brachial plexus injuries?
Safe patient positioning is always of top concern for robotics because of the extreme positioning, whether Trendelenburg, reverse Trendelenburg for foregut cases, or lateral side positioning. Brachial plexus injury can be caused by arm securement, shoulder securement, and the weight of the head pulling down in steep Trendelenburg. Positioning education so important! I am not aware of any brachial plexus injury caused by our positioning with the WaffleGrip system.

Q: You mentioned warming. How does WaffleGrip warm?
The securement portion doesn't, but it is part of the HotDog® patient warming system. The Underbody Mattress heats through the thin WaffleGrip material – something that can't be done with thick foam and gel pads, which was a huge and unexpected bonus. There's very little skin available to warm in robotic surgery, so warming from below is crucial. If space is available, a HotDog blanket can be added as well.

Q: If WaffleGrip is thin, how can it secure larger patients?
Although thin, WaffleGrip has a high coefficient of friction. There is no patient weight limit, and it can be used at angles up to 40 degrees. There are other benefits as well. It's single-use, so there are no contamination concerns and extremely little waste. Set-up is fast, so it doesn't delay OR turnover. It even comes with a slide sheet, making it very easy to reposition patients.

WaffleGrip™ and HotDog™ are registered trademarks of Augustine Surgical, Inc.

Note: For more information go to https://hotdogwarming.com/wafflegrip-trendelenburg-positioner/

Eleanor Markle provides consulting to medical device companies, including Intuitive Surgical, Inc. and Augustine Surgical. Inc.

OR teams should be on heightened alert for blood clotting.

Surgical teams should be aware of the higher-than-usual potential for patients in the reverse Trendelenburg position to develop deep vein thrombosis (DVT) during or following a procedure.

There is evidence in the literature that the reverse Trendelenburg position can significantly decrease a patient's femoral blood flow. As a result, these patients are more likely to suffer venous stasis or blood pooling, which can lead to blood clotting in the leg.

Mitigation strategies during prolonged surgeries include placement of a compression stocking over the patient's leg not just during surgery, but until they're fully mobile after the procedure. Another is the placement of an intermittent pneumatic compression device over the patient's leg to help improve blood flow by putting alternating amounts of pressure on the lower limb.

Best practices for DVT prevention may vary depending on the procedure types as well. For example, one study examines the conjunctive risks of high intra-abdominal pressure and the reverse Trendelenburg position during laparoscopic cholecystectomies. Acting on the recommendation that pneumoperitoneum can help patients with limited cardiac, pulmonary or renal reserves avoid venous stasis during these procedures, they sought to determine exactly how much pressure should be applied.

Fifty patients were classified in two 25-patient groups. One received high-pressure pneumoperitoneum (14 mmHg) and the other received low-pressure pneumoperitoneum (8 mmHg). Researchers detected that the changes in coagulation parameters were less significant at low-pressure pneumoperitoneum. "This study provides evidence of using low-pressure pneumoperitoneum during laparoscopic cholecystectomies, as changes in femoral vein hemodynamics and coagulation parameters were less pronounced."

This and other research suggests that DVT concerns should be top-of-mind for OR staff during any extended Trendelenburg procedure.

The practice was shown to prevent hypothermia and related complications.

Research shows heated irrigation fluids reduce risks of decreased body temperature and subsequent postoperative complications such as vasoconstriction of the blood vessels, impaired oxygen delivery through altered chemotaxis, and impairment of neutrophil and platelet function.

Researchers examined records of male patients who underwent endoscopic urology procedures between 2000 and 2016. These patients, usually 65 years or older, frequently receive irrigation fluids. The goal of the study, published in the Turkish Journal of Anaesthesiology & Reanimation, was to determine if the use of heated irrigation fluids would lower incidences of hypothermia and related complications.

Of the 1,632 patients studied, 1,369 received room temperature irrigation fluids and 264 received heated irrigation fluids. Researchers found a temperature loss of 0.10°C in the room temperature group, and an increase of 0.32°C in the heated group. All patients involved were found to be normothermic, with a temperature of at least 36°C in pre-op, without documented preoperative warming efforts.

"The study revealed that warmed irrigation fluids do have a significant impact on the prevention of postoperative hypothermia," say the researchers. "However, the study failed to present any statistically significant changes in postoperative clinical outcomes." They theorized that the health system's use of warming blankets prevented temperature decreases significantly enough to impact postoperative outcomes.

"Nevertheless, heat-preserving policies that integrate the use of warmed fluids for irrigation emdash especially in patients undergoing higher risk surgeries emdash may be beneficial in decreasing unwanted events secondary to postoperative hypothermia," they conclude.