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New Distal Pharyngeal Airway Contributes to Improved Patient Care and Outcomes: 2 Case Reports

Joanna Blondeau, CRNA, Staff CRNA, MedStream Anesthesia, Hilton Head Island, S.C.

Most airway management for anesthesia providers and airway experts is routine, predictable, uneventful and straightforward. However, when a challenging airway occurs in a clinical situation, it can lead to adverse effects and life-threatening consequences for the patient and anxious moments for the provider. The inability to successfully open the airway to ventilate or secure an airway with intubation are among the most challenging clinical situations that anesthesia providers encounter. Opening and securing the airway in a timely fashion is key to improving outcomes. Despite some improvements in airway management,1 these difficult events still contribute to morbidity and mortality and closed legal claims in anesthesia.2-4

Advanced airway tools have improved outcomes. Video laryngoscopes, laryngeal mask airways, positive airway pressure (PAP) devices, high-flow nasal cannula (HFNC) devices and cricothyrotomy kits all offer options for managing airways to assist patient breathing. However, core airway tools—the oropharyngeal airway (OPA) and nasopharyngeal airway (NPA)—have not advanced to address current patient needs, leaving a gap in airway management.

In the United States, the average patient is taller, heavier and older than patients from previous generations.5 These older, heavier patients are often prone to obstructive sleep apnea (OSA). Current OPA designs do not reach the distal pharyngeal tissue beyond the tongue that commonly obstructs the airway.6 An NPA can stimulate epistaxis, further compromising the airway. As a result, the risk for hypoxia due to upper airway obstruction during and after anesthesia has increased as well.7,8

To address challenges from apnea, hypoventilation or soft tissue obstruction during sedation or positive pressure ventilation, some anesthesia providers have begun to use a new distal pharyngeal airway (DPA) (Figure 1). The DPA stents open distal pharyngeal tissue beyond the tongue (Figure 2). When used with a connector, the airway also can bypass difficult mask ventilation variables with patients who have a beard, are obese or have OSA (Figure 3).

Figure 1

Figure 1. Distal pharyngeal airway.
All images courtesy of McMurray Medical.

Figure 2

Figure 2. Placement of the distal pharyngeal airway device.

Figure 3

Figure 3. Intraoral positive pressure ventilation while manually closing the nares and mouth.

Two case studies illustrate the utility of the new DPA device in obtaining a patent airway under urgent and difficult circumstances.

Case Report 1

A 60-year-old male with a body mass index (BMI) of 30 kg/m2 was hospitalized with COVID-19. The patient was intubated and on a ventilator in the ICU for two weeks. The surgeon was to perform a tracheostomy in the OR under general anesthesia. A bronchoscope was placed in the endotracheal tube to provide visualization of the percutaneous needle and wire placement. As the anesthesia team (anesthesiologists and CRNAs) carefully retracted the bronchoscope, the ETT inadvertently became dislodged. Oxygen saturation dropped quickly to approximately 30%. Mask ventilation and reintubation attempts by two different anesthesia providers, using both direct laryngoscopy and video laryngoscopy, were unsuccessful due to laryngeal edema from prolonged intubation. As the team was preparing for an emergent tracheostomy, an anesthesia provider quickly placed a DPA and started positive pressure intraoral ventilation. Oxygen saturation returned to baseline and the trach was subsequently successfully placed in a controlled setting.

Case Report 2

A 40-year-old male with a BMI of 40 and a medical history of cervical stenosis and bilateral arm neuropathy presented for anterior cervical discectomy and fusion (ACDF) surgery. A general anesthetic was started without incident, but intubation was challenging. After the surgical procedure was successfully completed, a hard collar was placed, and the awake patient was extubated with no coughing. However, in the recovery room, upper airway obstruction developed after the patient was medicated for pain, leading to desaturation and hypoxia.

Knowing that the patient had a challenging airway with excessive neck tissue and a large head, and that the surgeon did not want the collar to be removed to prevent disruption of the cervical repair, anesthesia personnel effortlessly placed the DPA. Intraoral ventilation was initiated and oxygen saturation reached baseline. With the DPA in place, the patient was assisted with occasional intraoral bag ventilation when saturation dropped. The DPA was removed when the patient was awake enough to maintain an open airway and adequate ventilation. The DPA proved to be an effective tool to keep the patient breathing without disrupting the surgical repair.

After this event, the nurses in this recovery room routinely used the DPA as an urgent intervention while waiting for anesthesia personnel to arrive with additional assistance. Staff who have limited intubating skills can place the DPA easily, helping to manage hypoxia quickly.


Airway management can be challenging in some patients. Airway tools have evolved, but traditional OPAs and NPAs historically relied upon as essential airway management devices have not advanced appreciably since their creation many decades ago. Today’s patients are more susceptible to upper airway obstruction due to increased weight, age and OSA. There is now a third option available to add to the core set of airway management tools. DPAs are easy-to-use devices that quickly open the distal tissue beyond the base of the tongue, helping to provide a patent airway, ventilation and a lower risk for hypoxia.

Blondeau reported no relevant financial disclosures.


  1. Cook TM. Strategies for the prevention of airway complications – a narrative review. Anaesthesia. 2018;73(1):93-111.
  2. Larson SL, Matthews RW, Jordan L, et al. Improving patient outcomes through closed-claims analysis: salient characteristics and patterns associated with respiratory events. AANA J. 2018;86(3):201-208.
  3. Mora JC, Kaye AD, Romankowski ML, et al. Trends in anesthesia-related liability and lessons learned. Adv Anesth. 2018;36(1):231-249.
  4. Cook TM, Scott S, Mihai R. Litigation related to airway and respiratory complications of anaesthesia: an analysis of claims against the NHS in England 1995-2007. Anaesthesia. 2010;65(6):556-563.
  5. NCD Risk Factor Collaboration (NCD-RisC). A century of trends in adult human height. ELife. 2016;5:13410.
  6. Garvey J, Pengo M, Drakatos P, et al. Epidemiological aspects of obstructive sleep apnea. J Thorac Dis. 2015;7(5):920-929.
  7. Ogden CL, Carroll MD, Kit BK, et al. Prevalence of childhood and adult obesity in the United States, 2011-2012. JAMA. 2014;311(8):806-814.
  8. Krogh M. Obesity and anesthesia practice. In: Nagelhout J, Elisha S, Plaus K, eds. Nurse Anesthesia. 6th ed. Elsevier Saunders; 2018:998-1014.

Used with permission from Anesthesiology News 3/2022

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Selecting the right blood/fluid warmer

Selecting the right blood/fluid warmer for your organization is a critical decision. Nowadays, due to multiple recent recalls of aluminum warmers — that according to the FDA’s warning their aluminum leaching levels “may cause serious adverse events including death”– decisionmakers should be fully aware of what’s inside their warmers of choice. The last thing you want is to face a recall situation just after you have invested considerable funds in procuring new warming devices.

A study published in 2019 expressed concerns regarding non-coated aluminum solutions. At the same time, the authors stated that “Even in a coated warming device, aluminum concentrations are detectable, but remain below the limit of quantification, LOQ (i.e. our methodology does not have the ability to differentiate between the concentrations we measured and the FDA threshold)[1]. Of note, some of the recent devices that were recalled are based on coated aluminum. Similarly, in TCCC’s recent Management of Hypothermia in Tactical Combat Casualty Care guidelines (2020), the authors also raised a concern regarding the utilization of aluminum warmers.

The risk of aluminum toxicity is nonexistent with the Warrior line, which is utilizing commonly-used medical-grade stainless steel coil for the fluids path and heat exchange functions. Our compact disposable unit (CDU) also includes PVC line with standard luer lock connection, to fit common blood/IV lines. A few temperature sensors are attached to the coil and report the blood/fluid temperature hundreds of time per second to the controller. Based on these readings, the controller regulates the energy distribution so as to ensure 38 degree Celsius output temperature.

Our technology is packaged in a compact and lightweight Expanded Polypropylene (EPP) casing. As per the British Plastic Federation, EPP “is a highly versatile closed-cell bead foam that provides a unique range of properties, including outstanding energy absorption, multiple impact resistance, thermal insulation, buoyancy, water and chemical resistance, exceptionally high strength to weight ratio and 100% recyclability”. With its excellent thermal insulation properties, the EPP casing ensures that heat is not dissipating; thus, allowing unmatched efficiency which is then translated into top warming performance.

Our technology is designed to address risks that may be associated with blood/fluid warming:

  • Hemolysis. Hemolysis might be accelerated by suboptimal design of the fluid path of the warming element. You expect your blood/fluid line to be smooth and homogeneous, then why make exceptions for the warmer’s fluid path (or as it is often called, the cassette)? In other words, preferably the fluid path of the warmer should be designed in an ‘undisrupted’ fashion. That is, and to the extent possible, the fluid path design should avoid for example abrupt turns, connection points, and flow changes (e.g. from a wide to narrow carrier and vice versa) in order to minimize sheer force, turbulence, cavitation, and air bubble formation, to name just a few potential complications associated with high flows and elevated pressure. Our fluid path has been designed in an undisrupted fashion so as to address the complications listed above.
  • Over/under heating. Another risk is over/under heating the blood/fluid being infused. Under heating is a more common issue especially with high flows and with rapid intermittent (bolus) flow methods, since most warmers cannot keep up with the job. If the warmer is unable to warm the fluids to body temperature at the rate being infused, you are introducing hypothermic fluids into your patient. Even room temperature fluids are far below body temperature, especially for severely sick patients suffering from shock. Our technology has been designed to support high flow rates and rapid intermittent (bolus) flow methods.
  • Aggressive heat transfer process. It seems logical that a relaxed heat transfer process from the heat exchanger to the blood/fluid is safer than an aggressive heat transfer process. Therefore, why not add this to your evaluation criteria? The most relaxed heat transfer mechanisms require a warming surface of 15-20 ml. We all love solutions with small priming volume, but we need to acknowledge that this may come at a ‘price’. And the price is a potentially aggressive heat transfer process from the heater to the blood, especially at elevated flows. With its 19ml priming volume, our heat exchange process is amongst the most relaxed heat exchange processes in the industry.
  • Unavailability. One of the most prominent risks associated with your blood/fluid warmer over the past years is that you will not be able to use it since there is a shortage of disposable sets or (as explained in the first part of this mail) due to a recall of the device. Ask users of enFlow, Level 1, ThermaCor, Thermal Angel, and several others to understand how frustrating this can get. And if there is one thing that COVID taught us, it is that complex solutions lead to complex supply chains and therefore to many months of lead times when the unexpected strikes. Therefore, make sure that the consumable of your solution of choice is simple enough to manufacture in large quantities, fast! Make sure that there are no chips that need to be placed into this consumable, otherwise you will be at the mercy of the market availability of chips, which is currently experiencing significant shortages. Our CDU has been designed for mass production and we have not experienced any shortage due to the adverse impact of COVID on global supply chains.

Finally, it should be noted that not only that our technology delivers unmatched performance, but also our per-use price is very affordable, especially compared with other modern warming solutions. A true win-win solution.

For more information click below,

Team Bell Medical

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An Evolving New Paradigm in Blood Warming: “A Bridge To Rapid Infusers”


Initially created on JANUARY 15, 2022 BY ARIEL KATZ, CEO QINFLOW

Rapid infusers are a great option for treating patients with severe hemorrhage. However, they require significant commitment from the hospitals: they are expensive to purchase, expensive to operate, and expensive to maintain. As importantly, they require significant ongoing investment in training so as to keep the staff adequately comfortable using them. Too often emergency personnel would avoid using their state-of-the-art rapid infusers simply because they are overwhelmed with their complex operation and time-consuming troubleshooting. In today’s environment, that requires hospital to rely on ‘travelling nurses’ to complement their staff. The situation is worsened since continuous education on rapid infusers is simply impractical.

Therefore, a growing number of hospitals are approaching us with a similar request: “we need a bridge to the rapid infusers”, they say. Indeed, there are other more practical solutions to transfuse warm blood fast. When used with flow-inducing devices such as pressure bag, hand pump, push-pull, electro-mechanical pump, or LifeFlow infuser, the Warrior line of next-generation blood warmers is an excellent bridge to the rapid infusers.  The following paragraphs introduce some of the key benefits of the Warrior over rapid infusers.

  • Speed. It is important to note that in over 95% of the cases rapid infusers are not required.  The patient will receive anywhere between 1 and 3 units of blood and rushed to the OR. In such instances, we celebrate that the Warrior delivers 1-3 units of warmed blood to patients much faster than rapid infusers, simply because set up time is reduced to just a few seconds.
  • Simplicity. Moreover, unlike rapid infusers, anyone can be trained to operate the Warrior. This removes the pressure that only a few expert nurses can operate the device flawlessly, as is often the case with rapid infusers. In addition, and unlike rapid infusers, troubleshooting the Warrior is fast and easy.  The Warrior’s simplicity has even greater value in situations of a mass casualty event since a stretched medical staff will greatly struggle to operate multiple rapid infusing devices concurrently.
  • Portability. One additional key advantage of the Warrior over rapid infusers is its portability. With rapid infusers, warm blood cannot be administered during a patient’s transfer to the next level of care, whereas the Warrior has been designed to facilitate patient’s transports (from field to ED, trauma, OR, and ICU). Unlike rapid infusers, the Warrior can be simply attached to the bed during patient’s transfer from ED to OR, thus freeing the hands of caregivers to perform more important stuff.
  • Unique Continuum of Emergency Care Proposition. The portability aspect enables a unique continuum of care proposition, whereby the same consumable can be used across the entire continuum of emergency care, thus simplifying patient handoff between emergency settings and reducing costs. If fully adopted by the hospital, further ROI benefits can be attained by streamlining training efforts, reducing dependency on dedicated staff, reducing spare part inventory, and eliminate monthly service calls and calibration endeavors that raid infusers typically require. If the hospital has a critical care transport team, treatment with the Warrior can commence even prior to the arrival of the patient to the ED.
  • Pediatric Applications. Another benefit of the Warrior is its ability to operate even with small-size catheters, designed for pediatric patients. Rapid infusers are limited to larger catheters which is part of the reason that a growing number of pediatric hospitals have adopted the Warriors along with the LifeFlow infusion device.
  • Maintenance Free. The Warrior does not require any routine service or any annual calibration.  It requires just one inspection every 5 years. Rapid infusers typically demand monthly service and calibration endeavors that overload the biomed team.
  • Aluminum Free. The Warrior is aluminum free; some rapid infusers contain aluminum in their fluid path.
  • Improved ROI. Finally, cost — both capital and consumables — is another huge benefit of the Warrior over rapid infusers.  A rapid infuser may cost $30k. At this price you can get approximately 8 Warrior AC devices…  A rapid infuser’s consumables are in the range of hundreds of dollars, considerably higher than the Warrior’s Compact Disposable Unit. There are also significant benefits related to reduction of indirect costs, such as simplified training, elimination of spare inventory, and elimination of complex service requirements, to name just a few.

To summarize, even the best-equipped medical centers are too often reluctant to use their rapid infusers due to their complexity. In such cases, therefore, the patients will get cold blood/fluid. While the Warrior is not a rapid infuser, it will outperform rapid infusers in greater than 95% of the cases, when just a few units of blood/fluid are required. In such cases, the Warrior will perform the job faster, more effectively, and more economically than the over-sized, complex, and expensive to operate rapid infusers.  Even in those few cases that rapid infusers are required, the Warrior can be used initially so as to accelerate the delivery of the first few units of blood to the patient.  In all these cases, the Warrior acts as an optimal bridge to the rapid infusersContact us for more information.

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Good News Line is OPEN!

Northeast Georgia Medical Center in Gainsville, GA has ordered and received 10 Warrior AC systems from Bell Medical and QinFlow for use in their operating rooms. 

This is our third order in the last 3 months for Warrior fluid warmers.  Children’s of Alabama, Birmingham, AL purchased 8 Warriors including the Warrior Hybrid and Warrior AC including the Warrior base unit with battery operation.  Kings Daughters Children’s hospital in Norfolk, VA. Has also invested in the Warrior with 8 systems. 

Warrior uses medical grade stainless steel tubing and state of the art micro processing to automatically adjust and control the temperature of fluids.  Warrior delivers 38 degrees C consistently regardless of flow rates from KVO to 290ml/min. The Warrior is perfect for the operating room, ED and Trauma but also has battery option offering unique portability for patient transport to ICU or use on Helicopter.  Combat hypothermia with the Warrior!   WE ARE ON A ROLL WITH WARRIOR!  Why:  Because Smith’s Level One is on recall for aluminum leaching and Smith’s Hotline is having warming set supply shortages AND the Warrior is amazing!  The Warrior is the only fluid warmer approved to work with the LifeFlow rapid infuser and the only warmer that excels in handling intermittent flow rates.  Bell Medical has the GOOD STUFF! 

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Aluminum: The Hidden Danger in Blood Warmers

Posted on by Stephen Alexander

Recently, there have been growing concerns from regulatory agencies, such as the FDA, as to the safety of aluminum containing medical devices, especially those involved with the infusion of fluids into patients. Just this past year, the FDA has recalled six intravenous fluid warming products due to evidence showing increased levels of aluminum. According to the FDA, “Exposure to toxic levels of aluminum may not be easily recognized and exposure effects may cause serious adverse events including death”. Some manufacturers have provided a potential solution by using coated aluminum surfaces. While these solutions certainly show improvement, they still release detectable levels of aluminum into infused fluids. The question is, are these levels safe or not? In this article, I will unfold some information about the recent recalls, the risk in aluminum, and other safety considerations regarding blood/fluid warmer. But I would like to start by making it clear to the reader that —

I’m not an expert, just an informer. First let me say that I am no expert in the field of toxicology, therefore it is beyond me to say for certain the safety of aluminum based warmers. That job I leave to regulatory agencies such as the FDA. However, once I reviewed the evidence and recalls put out by the FDA, I felt that I needed to make sure other providers are aware of the risks and recent recalls of these products. We should trust the sophisticated and rigorous medical approval system that we have in place. Therefore, it is my viewpoint that aluminum-based heaters that are regulatory cleared must be 100% safe to use. Nonetheless, we as critical care paramedics, nurses, and physicians must, as a minimal requirement, understand the risks associated with this method of warming. We owe it to our patients to be as well informed and up to date with the risks of certain treatments we provide, especially given the growing number of recalls of aluminum based warming devices.

Peer reviewed research of the risks. Aluminum toxicity can lead to a plethora of diseases ranging from Alzheimer’s, autism, breast cancer, to pancreatitis and pneumonia just to name a few (Igbokwe, 2019). In infants, aluminum toxicity is associated with impaired neurological development (Bishop, 1997). What’s even more alarming is that aluminum can also cause decreased iron absorption and anemia. Imagine trying to infuse blood products to correct anemia, and exposing your patient to toxic aluminum that causes the problem you are trying to reverse! Recalls of blood/fluid warmers due to the potential of aluminum leaching are typically identified as Class I recalls. These are the most serious as they are for devices that may cause serious injury or death! Patients most at risk are pediatric patients, specifically neonates and infants, pregnant women, geriatric populations, and those with decreased renal function or on dialysis.

Why manufacturers like to use aluminum in fluid warmers. Aluminum is used in a wide spectrum of medical devices, and when compared to other materials, it’s easy to see why. Aluminum has a large strength-to-weight ratio. This means that aluminum compared to other materials is stronger and lighter. Aluminum is also a good thermal conductor. In addition, aluminum is very malleable, thus it can be formed to almost any specification. Aluminum is a plentiful material as well; in fact, it is the most abundant metal in earth’s crust, making it very cost effective. All these reasons are why we find aluminum, not just in medical equipment, but in our everyday lives. It’s a good, plentiful, strong material that has countless applications. However, this article seeks to explain why using aluminum may not be the best option with respect to blood/fluid warmers.

Advancements in analytical technology have changed the stance on aluminum. If aluminum is unsafe, then why did the FDA approve of its use in fluid warmers initially? The answer is basically “you don’t know what you don’t know”. Regulatory agencies such as the FDA are only as good as the technology they have available to them. In recent years, advancements in technology have enabled regulators to measure more accurately the levels of aluminum produced from blood warmers that use that material. Keep in mind that when the FDA approved aluminum containing medical devices, it was before sensitive testing instruments were used to detect the minimum allowable limits of aluminum that is set forth today. This means that there was no way of knowing if these devices were leaching aluminum or not into the infused fluids. Therefore, these devices were developed, approved, and put on the market. Only until recently are regulatory agencies capable of measuring the threshold limits produced by these products, and the results — for some of these devices — are concerning.

Increased concern over aluminum containing warmers evident by 3 FDA recalls of 6 warming devices in just 6 months. Since March of this year there have been three separate recalls on fluid warmers that contain aluminum. The FDA has warned that the aluminum used in the heating elements is leaching into the fluids and being infused into patients. In March of 2021 ThermaCor 1200 disposable sets were recalled. The customers were notified of a Toxicological Assessment that there was potential aluminum leaching into fluids. Later, Eight Medical International’s Recirculator disposables were recalled in July of this year. The most recent recall was of 4 Smith Medical’s Level 1 configurations for the same reason, leaching of aluminum. This is on top of yet another global recall of the enFlow device in 2019. With so many recalls in such a short period, it does raise concern that blood warmers containing aluminum in their heating elements pose a potential risk to patients. You can read the FDA’s Letter to Health Care Providers on the recent recalls here.

Researchers find that coated aluminum may not prevent leaching. Manufacturers of blood/fluid warmers with aluminum heaters often make a distinction between uncoated and coated aluminum heaters. The latter (i.e. coated aluminum) is expected to be safer for patients, compared with non-coated aluminum. This makes sense. However, even blood/fluid warmers that utilize coated aluminum may pose a risk to patients. In June of 2019, researchers found that aluminum was still detectable in fluids infused with devices that use coated aluminum. The study compared aluminum release of coated and uncoated fluid-warming devices. The results of the study found that while aluminum release was less in coated devices, it still was elevated above baseline. In fact, the researchers stated that “our methodology does not have the ability to differentiate between the concentrations we measured and the FDA threshold.”(Perl, 2019).

Manufacturers may be predisposed to maintain the status quo. Despite the recent recalls, the default claim of manufacturers that use aluminum heaters is that the aluminum remains below the acceptable limits set forth by regulatory agencies. However, the accuracy of this claim is debatable, and the data that is used to defend these claims is often open for contradicting interpretations. At least in one recent case, the Canadian FDA publicly refuted such a claim proposed by Smiths Medical. Without getting into the specifics of this particular case, it’s easy to understand why manufacturers may resist a change. It goes without saying that they must trust that their solution is 100% safe in order to commercialize it. However, is it possible that this high level of confidence may also be fueled by some sort of an ‘organizational predisposition’? Let me try to explain: these manufacturers assumed significant risks and invested millions of dollars to overcome the demanding regulatory barriers that stand between any medical device innovation and the marketplace. Even after commercializing the product, they had to invest significant budgets in continuous engineering and regulatory affairs. Therefore, they need to see positive returns following these huge investments, otherwise future innovation might suffer. Certainly, a very complex and delicate situation that manufacturers must contend with.

Other associated risks of blood/fluid warming. It should be noted that warming fluids does come with other risks besides aluminum leaching. Let’s review some of these other risks:

  • Hemolysis. One risk is hemolysis due to the age of blood products given. This isn’t necessarily a risk associated only with warming blood products, but just a general risk overall. As the products age, red blood cells have a higher chance of rupturing. That’s why it’s important to infuse blood products before the expiration date.
  • Excessive sheer force, turbulence, and cavitation. Hemolysis might be accelerated by suboptimal design of the fluid path of the warming element. You expect your blood/fluid line to be smooth and homogeneous, then why make exceptions for the warmer’s fluid path (or as it is often called, the cassette)? In other words, preferably the fluid path of the warmer should be designed in an ‘undisrupted’ fashion. That is, and to the extent possible, the fluid path design should avoid for example abrupt turns, connection points, and flow changes (e.g. from a wide to narrow carrier and vice versa) in order to minimize sheer force, turbulence, cavitation, and air bubble formation, to name just a few potential complications associated with high flows and elevated pressure. Why don’t you simply try to look under the hood of your chosen warmer?
  • Over/under heating. Another risk is over/under heating the fluids/blood being infused. I believe that under heating is a bigger and more common issue especially with high flows and with intermittent flow methods. If your agency requires high flows or uses an infusion device that utilizes intermittent flow, most warmers cannot keep up with the job. If the warmer can’t physically warm the fluids to body temperature at the rate being infused, you’re introducing hypothermic fluids into your patient. Even room temperature fluids are far below body temperature, especially for severely sick patients suffering from shock.
  • Aggressive heat transfer process. It seems logical that a relaxed heat transfer process from the heat exchanger to the blood/fluids is safer than an aggressive heat transfer process. Therefore, why not add this to your evaluation criteria? The most relaxed heat transfer mechanisms require a warming surface of 15-20 ml. We all love solutions with small priming volume, but we need to acknowledge that this may come at a ‘price’. And the price is a potentially aggressive heat transfer process from the heater to the blood, especially at elevated flows.
  • Unavailability. One of the most prominent risks associated with your blood/fluid warmer over the past years is that you will not be able to use it since there is a shortage of disposable sets or a recall of the device. Ask users of enFlow, Level 1, ThermaCor, Thermal Angel, and several others to understand how frustrating this can get. And if there is one thing that COVID taught us, it is that complex solutions lead to complex supply chains and therefore to many months of lead times when the unexpected strikes. Therefore, make sure that the consumable of your solution of choice is simple enough to manufacture in large quantities, fast! Make sure that there are no chips that need to be placed into this consumable, otherwise you will be at the mercy of the market availability of chips, which is currently experiencing significant shortages.

A solution. Clearly the wrong answer to prevent aluminum leaching from blood/fluid warmers is to not utilize a warmer. Myself and other colleagues have written extensively about the importance of warming fluids, especially blood products in rapid transfusions. You can read some of those articles here .One practical solution to this problem is utilizing a warmer that is aluminum free in the first place, or, if you decide to use an aluminum warming solution, then do your due diligence about the solution. There are several prehospital and hospital solutions that are aluminum free, such as the Thermal Angel, Quantum, and Ranger, to name just a few. QinFlow’s Warrior is another excellent example of an aluminum-free warmer: it has battery and AC power sources and it therefore fits both prehospital and hospital settings. It has amazing performance levels, measured in maximum delivery rates. And as importantly, its per-use price is very competitive. You can read more about the Warrior here.

Summary & Conclusion. New, more sensitive, monitoring technology has made it possible for regulatory agencies to detect trace levels of aluminum, before unknown to us. Exposure to toxic levels of aluminum, according to the FDA, “may cause serious adverse events including death”. With that information, three recalls of 6 devices have been issued within the past few months over growing concern of elevated aluminum levels in fluids infused by products containing aluminum heating elements. We’ve seen that not even coated aluminum surfaces prevent leaching into fluids. The only way to ensure that zero aluminum is leaching into your patients is most probably to utilize solutions that are aluminum free. While there are several options out there, the QinFlow’s Warrior is a good place to start. Their fluid path is 100 percent aluminum free. They are also amongst the most cost efficient solutions on the market. A true win win. QinFlow’s disposable cassettes have a comfortable and gentle priming volume of 19mL. Finally, the Warrior is rugged enough to withstand high pressures of intermittent flow and can warm near freezing blood products to body temperature within seconds, safely!


Bishop NJ, Morley R, Day JP, Lucas A. Aluminumneurotoxicity in preterm infants receiving intravenous-feeding solutions. New England Journal of Medicine 1997;336: 1557–61

Igbokwe, I. O., Igwenagu, E., & Igbokwe, N. A. (2019). Aluminium toxicosis: a review of toxic actions and effects. Interdisciplinary toxicology, 12(2), 45–70.

Perl, T., Kunze-Szikszay, N., Bräuer, A., Quintel, M., Röhrig, A.L., Kerpen, K. and Telgheder, U. (2019), Aluminium release by coated and uncoated fluid-warming devices. Anaesthesia, 74: 708-713.

Stephen Alexander

Stephen Alexander is a Critical Care Paramedic residing in Little Rock Arkansas. He enjoys writing informative and educational articles about pre-hospital medicine. Stephen started his career in EMS by enlisting in the Army as a 68W Combat Medic. He then attended the U.S Army Flight Medic program through UTHSCSA and received his paramedic license through NREMT. He then went to RUSH Advanced Trauma Training Program in Chicago and attained his CCEMTP. He currently flies for the Arkansas Army National Guard MEDEVAC unit.

Full article can be found here:

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Innovative MAC anesthesia approach to reducing nausea and vomiting!

Patients experience nausea and vomiting 30-50% of surgical recoveries!  There are NO positive reviews from a patient that vomits post-surgery.  PONV is costly in many ways including slowed patient recovery, poor patient experience and in increased staffing needs.  Reducing PONV can help make hospitals and surgery centers become more productive, more pleasant and more profitable and anesthesia providers happier. 

Aromatherapy from the vanilla infused Capnomask O2/CO2 mask is a safe and effective tool for anesthesia to use to reduce PONV, provide oxygen and monitor the patients breathing to assure safe MAC anesthesia. 

The vanilla infused Capnomask offers a drug-free therapy to give anesthesia a proactive way to reduce the chance of a patient experiencing nausea and vomiting.  The Capnomask offers other advantages including:

  • Excellent patient oxygenation of over double the FiO2 of nasal oxygen canula.
  • Capnomask acts as a physical shield or barrier reducing atomization of a patient’s exhalation thus protecting nurses, surgeons and anesthesia by reducing the spread of germs including Covid19.
  • Capnomask comes preassembled with oxygen tubing and 10’ EtCO2 sample line to safely monitor a patient’s breathing to assure no hypoventilation incidents.
  • Vanilla infused scent reduces nausea and vomiting reducing PONV.
  • Low cost of Capnomask compared to cost of DIY or Do It Yourself options of converting a standard oxygen mask with IV catheter and adding an EtCO2 sample line.
  • Reduced anesthesia time to set up DIY version for MAC cases. 

Further benefits of the Capnomask:

  • Reducing Costs
    • Reduced staffing costs and resources used to administer and monitor PONV treatments
    • Reduced drug costs and side effects of nausea prevention drugs
    • Reduced involvement of pharmacy and medication costs
    • Reduced length of recovery time and improved PACU throughput
    • Improved HCAHPS scores with less PONV
  • Adding Value
    • Preventing nausea with the aromatherapy of Capnomask improves patient experience.
    • Satisfaction scores improve with the reduction in PONV
    • Less staff required for PONV intervention if prevented by proactively using Capnomask
    • Capnomask may be considered an added component of ERAS or Enhanced Recovery after Surgery
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Corneal Abrasion; problem what problem?

Well, it all depends on which side of the fence you are sitting on. Most medical definitions describe a corneal abrasion as a painful scrape or scratch on the surface of the clear part of the eye. This clear tissue of the eye is known as the cornea, the transparent window covering the iris, the circular coloured portion of the eye. Descriptions also state that in most cases the cornea heals in a couple of days and all symptoms pass.

A patient on the other hand would probably describe a corneal abrasion as painful to say the least. In fact, it may be extremely painful. This is because the cornea has a high concentration of nerve endings, so it is going to be really painful. Alongside the extreme pain they may feel as though there is something in their eye. The eye will look red, vision will be blurred and there will be excessive tearing. They may be sensitive to light but closing the eye may only cause the pain to intensify. There may be vision loss and headaches which will cause concern.

So, this can be an extremely uncomfortable situation for someone to be in and they need treatment immediately to relieve the pain and allow them to see clearly.

How does a corneal abrasion occur? The answer is, quite easily. Minor abrasions can be caused by:

  • Poking your eye with a fingernail, pen, or makeup brush.
  • Rubbing it too hard.
  • Wear poor-fitting or dirty contact lenses or wearing them for too long.
  • Walking into something like a branch of a tree.

More serious abrasions can occur from:

  • Getting chemicals in your eye.
  • Get dirt, sand, sawdust, ash, or some other foreign matter in your eye, especially at work and not wearing eye protection.
  • Play sports or engaging in high-risk physical activity without eye protection.

You may be surprised to learn that a corneal abrasion can occur when you are having an operation and are anaesthetised. How can that possibly happen, you are probably thinking. Again, the answer is quite easily. But before we consider how a corneal abrasion can occur in the operating theatre, we need to look at how the eye behaves when it is anaesthetised, and the steps taken to protect your eyes when you have an operation.

A general anaesthetic can have several effects on your eyes, including:

  • It can cause lagophthalmos which is a failure of the eyelids to fully close. During normal sleep, lid closure is maintained by the tonic contractions of the orbicularis muscle. Lagophthalmos only occurs in about 4% of people during normal sleep. However, under anaesthesia one study demonstrated that 59% of patients failed to have complete eyelid closure.(1)
  • Tear production and stability are significantly reduced which causes the cornea to dry out.
  • Bell’s phenomenon is a protective mechanism that turns the eyes upwards to protect the cornea. It occurs naturally during sleep, but this mechanism is also lost during general anaesthesia.

Therefore, you can see that the eyes are compromised when you are given a general anaesthetic and so must be protected from being damaged. But how common is getting a corneal abrasion in the operating theatre, what causes it and what is done to protect the eyes?

A corneal abrasion is the most frequent ocular complication of general anaesthesia.(2) The American Society of Anaesthesiologists’ closed claims analysis of ocular injuries associated with general anaesthesia, 35% were corneal abrasions, of which 16% resulted in permanent ocular damage.(3)

Because the eyes are compromised during general anaesthesia, almost anything can cause a corneal abrasion. The list is endless. A watch strap, name badge, the anaesthetist’s hands, facemasks, drapes, instruments laryngoscope, skin preparation solutions, or the direct irritant effect of inhalational anaesthetic agents. In recovery the eye may be injured by face masks, the patient’s fingers, or the bed linen. However, most corneal abrasions are caused by the failure of the eyelids to close properly leading to corneal drying.(4) I will return to this point later.

It’s clear that the eyes need some solid protection to prevent them from being damaged. So, what is done in today’s modern, high tech expensive operating theatre? They do this.


Usually, a theatre technician will use some general-purpose tape that is lying on a trolley or in their pocket and your eyes will be taped shut. Prior to taping a protective ointment or gel may be applied. However, we all know that adhesiveness of tape varies and that used in the operating theatre is no different. Too little stick may not ensure or maintain complete eyelid closure, leading to moisture loss from the eye. Too much stick may cause eyelid bruising, irritation and skin tears or eyelash loss on removal. Tape used is usually opaque making it difficult to tell if the patients’ eyes are completely closed. Frequent removal and reapplication of the tape makes it less sticky and prone to falling off Additionally, the anaesthetist may need to check pupil dilation and the tape needs to be removed and reapplied whilst wearing surgical gloves. Not an easy thing to do!

So, back to our patient. Despite taping the patient’s eyes being taped during an operation, the tape was opaque, and no one spotted that the eyes opened during the operation causing the cornea to dry out. When the patient woke up, they had a really painful and sore red eye. A saline washout of the eye was tried but that didn’t work. In the end an ophthalmologist was called to examine the patient and a corneal abrasion, caused by the eye drying out was diagnosed. This required treatment including pain management, antimicrobial prophylaxis, a pressure patch, and close monitoring meaning the patient was in hospital for an extra day.

Could all this have been avoided? Could the anaesthetist have spotted that the patients’ eyes had opened during the operation and closed them? Could a corneal abrasion have been avoided and the patient not had such a painful experience? Could the hospital have avoided all those extra treatment costs such as consultant time, drugs, and bed usage?

Instead of using opaque general-purpose tape to protect the patients’ eyes, the hospital should have used EyePro™ instead.


Why should we use EyePro™ instead of tape?  EyePro™ is a unique eyelid cover designed by an anaesthetist to maintain eyelid closure during general anaesthesia.

It ensures rapid, complete, and safe eyelid closure. By sealing around the eye circumferentially, all moisture is retained, thus preventing the eye from drying out. Additionally, a clear central window allows direct observation of eyelid closure.

EyePro™ has a patented dual zone design whereby an inner transparent window allows intra-operative assessment of eyelid closure, while an outer, more rigid, opaque zone allows for easy handling and excellent conformity to the eye socket. The inner window has a gentle adhesive which helps to maintain eyelid closure and reduces eyelid trauma and/or eyelash removal. The outer zone has slightly stronger adhesive that maintains eyelid closure for extended periods. Also, non- adhesive tabs allow for easy handling, application, and removal, even while wearing gloves.

Additionally, each pair of EyePro™ comes packaged together in a sterile wrap to decrease the risk of cross contamination. In a world where we are going to have to live with Covid-19 anything that reduces the risk of infection must be a good thing. But that will be the subject of another article.

EyePro™ is more expensive than tape I hear you say. Yes, it is. That’s because it has been specifically designed for one purpose; to protect the eyes during general anaesthesia. In doing so, EyePro™ provides a superior level of protection against corneal abrasions. And don’t forget those extra treatment costs such as consultant time, drugs, and bed usage. An extra day in hospital would cost approximately $1800/day in the USA, $AUD1000/day in Australia, £400/day in the UK and €600 in the EU.

EyePro™ is a major advance in keeping the patients’ eyes safe during general anaesthesia. Remember, most corneal abrasions are caused by the failure of the eyelids to close properly leading to corneal drying. EyePro™ allows the anaesthetist to ensure the eyes remain closed, thereby reducing the risk of corneal abrasion. This leads to a better patient experience, quicker recovery time and a reduction in the use of valuable hospital resources such as drugs, bed occupancy and clinical time. Additionally, within the overall cost of treating the patient EyePro™ could also save you money. It really is a no brainer!!!


  1. Batra YK & Bali IM. Corneal abrasions during general anaesthesia. Anaesthesia and Analgesia 1977; 56: 363– 5.
  2. Terry TH, Kearns TP, Grafton‐Loue J, Orwell G. Untoward ophthalmic and neurological events of anaesthesia. Surgical Clinics of North America 1965; 45: 927– 9.
  3. Gild WM, Posner KL, Caplan RA, Cheney FW. Eye injuries associated with anaesthesia. Anaesthesiology 1992; 72: 204– 8.
  4. White E, Crosse MM. The aetiology and prevention of peri‐operative corneal abrasions. Anaesthesia, 1998, 53, pages 157–161

Author: Niall Shannon, European Business Manager, Innovgas

This article is based on research and opinion available in the public domain.

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Doctor There’s a Problem in the Recovery Room

The operation had been a long, but it had been a success. The patient had been taken into the recovery room and was being looked after by theatre staff as they were slowly woken up. In theatre the anaesthetist was talking with colleagues about the operation.

Suddenly, a member of staff put their head through the door of the recovery room and looking at the anaesthetist said, “doctor there’s a problem in the recovery room.”

Upon entering the recovery room, the anaesthetist found that the patient, had started to recover but was biting down on the reinforced laryngeal mask airway (LMA). The anaesthetist tried to encourage the patient to stop biting, but that didn’t work. The patient bit right through the LMA and this part was removed from his mouth. Remarkably the patient could still breathe through the bitten off end. A few minutes later the patient had recovered enough to spit the remnants of the LMA out. The photographs below clearly show the aftermath. 


Thankfully, that was a good outcome both for the patient and the anaesthetist and their team. But there are two other scenarios that could have occurred:

  • The patient could have broken their teeth and suffered dental damage. I wrote about this last year and pointed out the consequences both from a repair perspective and a financial one for the patient and the hospital.
  • Another more serious scenario is that the patient obstructs the lumen of the LMA or the LMA blocks the upper airway. There is a real risk of desaturation and negative pressure pulmonary oedema. This is a dangerous and potentially fatal condition. Negative pressure pulmonary oedema (NPPE) or post obstruction pulmonary oedema (POPE) is a clinical entity of great relevance in anaesthesiology and intensive care. The presentation of NPPE can be immediate or delayed, which therefore necessitates immediate recognition and treatment by anyone directly involved in the perioperative care of a patient.(1)

So, what do we know about negative pressure pulmonary oedema or Post Obstruction Pulmonary Oedema?

There are few studies in the public domain that look at the incidence of NPPE. The incidence of NPPE has been reported to be 0.05%–0.1% of all anaesthetic practices. However, it is suggested that it occurs more commonly than is generally documented. According to one estimate, NPPE develops in 11% of all patients requiring active intervention for acute upper airway obstruction (2) . In a small review of case reports where laryngeal mask is cited, 60% reported that the patient bit through the LMA and of that group ⅔ reported that the patient developed a pulmonary oedema (3) .

The review concluded, ”The vast majority of the papers found are case reports, though a single survey suggests that biting of an unguarded laryngeal mask airway (LMA) is not an uncommon event. Complications of biting include airway obstruction and the development of negative pressure pulmonary oedema, neither of which would be welcome events in the resuscitation area.”

In a U.K. national survey of the use of bite guards and critical incidents involving the laryngeal mask airway (3) a postal questionnaire was sent to 451 anaesthetists with a 42% response rate. 63% of consultants, 45% of SpRs and 43% of recovery staff never used a bite guard in conjunction with a laryngeal mask airway of any sort. However, biting of a laryngeal mask airway by a patient, resulting in airway obstruction, had been experienced by 18 users of the flexible laryngeal mask airway (7.3%) and 71 users of the standard laryngeal mask airway (18.8%).

The recovery staff reported an average of two incidents per month of laryngeal mask airway obstruction. The authors concluded that the use of a bite guard with a laryngeal mask airway is an uncommon practice but the occurrence of airway obstruction with the laryngeal mask airway is high.

An upper airway obstruction is the cause of negative pressure pulmonary oedema. A blocked or broken LMA caused by biting is one cause. Others include hanging, strangulation, upper airway tumours, foreign bodies, croup, choking, migration of Folly’s catheter balloon used to tamponade the nose in epistaxis, near drowning, goitre mononucleosis, big tonsils, hypertrophic adenoids, or a redundant uvula.

Once the upper airway is obstructed a very large, negative, intrathoracic pressure is generated by the patient’s increased effort to breathe. This causes pulmonary oedema or fluid build-up in the lungs resulting in acute respiratory failure. The onset of pulmonary oedema is usually rapid (within a few minutes after signs of upper airway obstruction). The patient will become agitated, may look frightened, will breathe rapidly, may become tachycardic, crackling sounds or rales may be heard with a stethoscope and pulmonary secretions become frothy and pink as progressive oxygen desaturation occurs.

Quick thinking and action are required to remove the blockage causing this emergency. If the blockage were caused by a broken LMA the patient would need to be rapidly re-anaesthetised and paralysed to allow the LMA to be removed. This would also allow reoxygenation to occur if the patient were desaturated. This intervention not only exposes the patient to more drugs but if desaturation carries on for long enough the situation can become an anaesthetic emergency. The Difficult Airway Society Guidelines for the management of tracheal extubation(4) recommend the following for the management of negative pressure oedema.

  1. Treat the cause: relieve the airway obstruction.
  2. Administer 100% O2 with full facial CPAP mask. In addition to relieving upper airway obstruction, CPAP may reduce oedema formation by increasing mean intrathoracic pressure and minimise alveolar collapse by increasing functional residual capacity, improving gas exchange, and reducing the work of breathing.
  3. Nurse the patient sitting upright.
  4. If there is fulminant pulmonary oedema with critical hypoxaemia, tracheal intubation and mechanical ventilation with PEEP are necessary. Less severe hypoxia responds to supplemental oxygen and ⁄ or non-invasive ventilation, or CPAP.
  5. Intravenous opioids may help reduce subjective dyspnoea.
  6. Chest radiography may exclude other complications of difficult airway management and causes of hypoxia (gastric aspiration, pre-existing infection, pneumothorax, barotrauma, pulmonary collapse).
  7. Frank haemoptysis may necessitate direct laryngoscopy and ⁄ or flexible bronchoscopy.
  8. Diuretics are often administered, but their efficacy is unproven.

The Difficult Airway Society also comment,” Post-obstructive pulmonary oedema may be prevented through use of a bite block during emergence.”

And so, let us finally consider the economics of managing a patient who develops negative pressure oedema from biting through their LMA. The first thing to say is that the patient would probably need to spend more time recovering in hospital either in the recovery room, on a ward, HDU or even ICU. Further investigations such as a chest x-ray or blood gas analysis might be needed. Interventions as described in the Difficult airway Society Guidelines may also be required.

Uncovering the daily cost of a hospital bed is not easy and the data is quite old. A stay in a hospital bed without factoring in investigations and/or interventions would cost approximately $1800/day in the USA, $AUD1000/day in Australia and £400/day in the UK. Private healthcare charges would be higher. In most health care systems around the world the daily cost of an ICU bed is in 4 figures. In the USA it is approximately $6000/day, Australia approximately $AUD4000/day and the UK approximately £2000/day. A bite block such as BiteMe™ costs $1.48 per patient and would reduce the incidence of negative pressure pulmonary oedema resulting in fewer patients needing to spend extra time in ICU.

I leave you to make your own mind up when it comes to cost effectiveness.

So, what can we determine from this article?

  • The incidence of NPPE is poorly understood and probably under reported.
  • NPPE can result in acute respiratory failure which is a dangerous and potentially fatal condition.
  • Biting through a laryngeal mask airway (LMA) is not an uncommon event.
  • Despite being recommended by the Difficult Airway Society the use of a bite block with a laryngeal mask airway is not a common practice.
  • Using a bite block in conjunction with an LMA would reduce the incidence of potentially fatal negative pressure pulmonary oedema caused by a patient biting through their LMA.
  • Using a bite block such as BiteMe™ to prevent NPPE caused by the patient biting through the LMA and the upper airway becoming blocked is a more cost-effective option than having the patient spend extra time in ICU.

By using a specifically designed bite block such as BiteMe™. Which is made of a very strong, but soft, plastic that resists the shear forces of a human bite very well reduces the risk of desaturation and/or Negative pressure pulmonary oedema if the patient’s airway device becomes obstructed.

The combination of the soft plastic surrounding a closed air-filled space means that when a patient bites down, there are two forces opposing the bite. This means BiteMe™ has a spongy recoil and therefore reduces the risk of the patient severing the LMA if they start biting during emergence.



  1. Bhaskar B, Fraser JF. Negative pressure pulmonary edema revisited: Pathophysiology and review of management. Saudi J Anaesth. 2011 Jul-Sep; 5(3): 308–313.
  2. Tami TA, Chu F, Wildes TO, Kaplan M. Pulmonary edema and acute upper airway obstruction. Laryngoscope. 1986;96:506–9.
  3. Heptinstall E, Heptinstall L. Should Bite Guards Be Used with Laryngeal Mask Airways In Adults? Best Evidence Topics Database (BestBETS). March 2015.
  4. Popat M (Chairman),Mitchell V, Dravid R, Patel A, Swampillai C, Higgs A. Difficult Airway Society Guidelines for the management of tracheal extubation. Anaesthesia 2012, 67, 318–340

Author: Niall Shannon, European Business Manager, Innovgas

This article is based on research and opinion available in the public domain.

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