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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. 

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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.

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References

  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
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Author: Niall Shannon, European Business Manager, Innovgas

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

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LifeFlow Blood and Fluid Infuser: Volume resuscitation when minutes matter!

LifeFlow offers improved resuscitation through earlier and controlled fluid delivery. LifeFlow is a hand operated rapid infuser for critically ill patients who require urgent fluid delivery. 

  • Controlled hand-operated rapid infuser
  • Easy to use, intuitive and safe
  • Four times plus faster than pressure bag delivering 500ml in less than 2 minutes
  • Reverses shock and restores tissue perfusion saving lives
  • Improves outcomes and reduces mortality
  • Easy set up and priming with set up in less than 40 seconds
  • Measured delivery with 10ml delivered with each trigger pull
  • Built in “force reducer” reducing infuser force protecting IV site from blow outs
  • Works with the QinFlow Warrior blood warmer
  • Eliminates “Pull/Push technique for pediatrics
  • Fluids can be delivered through 24 gauge catheter and blood through a 22g. 
  • 5 times faster than pressure bag
  • Great for hypotension
  • Safety system prohibits more than 200PSI pressure delivery

Click to view a short training video

Can be used with Warrior Blood and Fluid Warmer

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The face mask that could end the pandemic

By Keri Enriquez

Updated 10:24 AM ET, Sat January 23, 2021

 (CNN)Getting Americans masked up is a top priority for the Biden administration.

Biden, who calls wearing masks “a patriotic act,” signed an executive order Wednesday — his very first as President — to ask Americans to wear masks of their choice for the first 100 days of the new administration. The executive order also requires mask use on all federal property, though in this case, not just any old mask will do.

On Wednesday, after the inauguration, White House press secretary Jen Psaki showed off her bright white N95 mask in the press briefing room. “I wore it out, of course, here today and will continue to do that,” Psaki said after removing her medical-grade mask and before turning to questions.

CDC reports record number of daily Covid-19 vaccinations as states struggle with supply

N95 masks are considered the gold standard in personal protective equipment because they block 95% of large and small particles utilizing a unique electrostatic filter.

The filter works by trapping neutral particles like bacteria and viruses before they pass through the mask, protecting the wearer and those around them. It’s similar to how socks might get stuck to a blanket in the dryer. The N95 mask, which costs roughly $5, also fits securely to the face, eliminating most of the leakage that may occur with a loose-fitting cloth or paper mask.

Studies have shown that masks significantly decrease the chances of transmitting or contracting the coronavirus. But not all masks provide equal protection. Depending on the fabric and number of layers, homemade and simple cloth masks have a range of effectiveness that can be as low as 26%, which leaves the wearer vulnerable.

Some experts like Brigham and Women’s Hospital and Harvard Medical School physician Dr. Abraar Karan have been advocating for public use of N95 masks from the start of the pandemic. In an interview with CNN Chief Medical Correspondent Dr. Sanjay Gupta, Karan outlined why N95s are critical at this stage of the pandemic.

“If for four weeks the country essentially wore these masks in those risky settings like that indoors, what kind of difference do you think it would make?” Gupta asked.

“This would stop the epidemic,” Karan responded.

Dr. Gupta on Covid-19: This is the worst it’s ever been 05:46

The quality of protection a face mask can provide is crucial. A respiratory illness like the coronavirus is transmitted through aerosols, tiny particles that waft and hang in the air. Some virus-carrying particles are small enough to travel through or around lower-quality masks, making the wearer vulnerable to inhalation of viral particles.

“We know now that aerosols spread best when there is poor ventilation, crowding and close contact that’s prolonged,” Karan told Gupta in an interview. “So we were arguing that actually in those settings, cloth masks alone are not going to block aerosols.”

Karan is not the only expert who has been vocal in support of better quality masks for the general public. Former US Food and Drug Administration Commissioner Dr. Scott Gottlieb wrote in an op-ed in the Wall Street Journal that “encouraging Americans to wear higher-quality masks is a simple step that might make a difference.”

The biggest problem is lack of supply. This week marked a full year of the coronavirus, and the Biden administration has committed to invoking the Defense Production Act more often to boost manufacture of N95 masks and other critical supplies. Experts hope manufacturing will hit a speed to be able to sufficiently supply the population.

“An N95 that’s well-fitted clearly is the best that you can do,” National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci told CNN Friday. “You could get production of that at a much higher rate now.”

Karan believes N95 masks could be an essential asset in reopening the economy as the vaccine rollout remains sluggish and quarantine fatigue soars.

The huge stakes of Biden’s new Covid-19 plan

“If we have better personal protection for people, they can more safely go back to work. They can more safely re-engage, especially if testing and tracing is not where we need it to be,” Karan said.

“This was going to be one way to get people back in and get the economy back up.”

Some European countries are already taking that step to prevent coronavirus spread within their borders. Earlier this week, Germany and France mandated that all citizens wear high filtration masks like the N95 in all public places.

After months of treating coronavirus patients, Karan says it’s time to invest in making sure masks people wear are even more effective. “Focus on getting better masks to as many people as possible, focus on the messaging around masks, be consistent with your messaging, make masks part of American culture to stop the epidemic.”

The key here is to always wear a mask whenever you’re in public. One study in Lancet Digital Health found that a 10% increase in mask-wearing could lead to a three-fold increase in the odds of maintaining control over virus transmission in a community. The ability to control the spread of the coronavirus is in our hands — and on our faces.

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Novaerus Defend 1050 air purifier approved by FDA as 510(k) Class II Medical Device

Novaerus Defend 1050 cleared by FDA as 510(k) Class II Medical Device to inactivate and filter out airborne virus and bacteria for medical purposes

Defend 1050 uses patented NanoStrike® technology to damage and inactivate airborne micro-organisms.

Dublin, Ireland and Stamford, CT – Novaerus, a WellAir company that delivers clean air solutions to help prevent the spread of infectious outbreaks, announced today that the U.S. Food and Drug Administration (FDA) cleared the Novaerus Defend 1050 (NV 1050) as a 510(k) Class II Medical Device to inactivate and filter out micro-organisms, including virus and bacteria, for medical purposes. The Novaerus Defend 1050 is the first system that uses NanoStrike®, a patented plasma generating technology, to receive FDA 510(k) clearance.

The Novaerus Defend 1050 is a free-standing, portable recirculating air cleaning system designed for additional frontline protection in healthcare settings such as operating rooms, intensive care units, in vitro fertilization labs, emergency rooms, waiting and treatment areas, neonatal units, and other critical environments including those performing aerosol-generating medical procedures (AGMP).

The Defend 1050’s NanoStrike technology uses a plasma field that rapidly inactivates micro-organisms at the molecular level. Within 15 minutes, the Defend 1050 has demonstrated a 4-log (99.99%) reduction of the MS2 bacteriophage RNA virus, an accepted surrogate for SARS-CoV-2. The Defend 1050 also showed a 4-log (99.99%) reduction in Bacillus Globigii endospores (bacterial spores) within 15 minutes, which was maintained over the prolonged operation (24 hours).

The Defend 1050 is currently used in hospitals and healthcare settings worldwide. Given the rapid spread of COVID-19, WellAir moved quickly to understand how this device could potentially combat the virus while moving it through a thorough FDA medical device clearance process. Additionally, the Defend 1050 meets relevant performance criteria in the FDA Guidance, which provides non-binding recommendations that may reduce the risk of viral exposure for patients and healthcare providers during the current public health emergency.

“Our team of outstanding engineers and scientists have been focused on delivering innovative and powerful airborne infection control devices. The FDA clearance on the Defend 1050 is a critical milestone for our company, validating our work to deliver a safe and effective medical device,” said Dr Kevin Devlin, WellAir CEO. “The Defend 1050 has demonstrated tremendous efficacy in third party testing against viruses, bacteria, VOCs, and particulate matter, which makes it an ideal solution for hospitals and healthcare settings. As we continue to see an alarming rise in the number of COVID-19 cases, we have moved quickly to make the device readily available.”

Defend 1050 utilizes multiple stages to reduce airborne micro-organisms. The first stage is a general air pre-filter that captures particles between 4 and 10 microns from the input airflow. This filtered air passes through a series of NanoStrike coils (plasma generators) that damage and inactivate micro-organisms on contact, including viruses and bacteria. The resulting inactive particulates are trapped by a HEPA (High-efficiency Particulate Air) filter. In a final cleaning stage, an activated carbon filter traps VOCs in the airstream before the air is released into the environment.

The Defend 1050 system is delivered complete with all components necessary for immediate use. It can be wheeled easily by a single person to the desired point of use and plugs into standard outlets. Five airflow speed settings enable optimization to each healthcare environment. The only routine maintenance required is a calendar-based filter change schedule.

If you are a medical or healthcare facility interested in learning more about the Novaerus Defend 1050 or other Novaerus products, additional information can be found here, or please contact us

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Xavant Technology Announces First Dual-Sensor Neuromuscular Patient Monitor

The Stimpod NMS450X NMT monitor for Anesthesia first to feature both AMG and EMG modalities in one single, portable patient monitoring system.  

Pretoria, South Africa, October. 15, 2019 – Xavant Technology, a pioneer in neuromuscular monitoring and innovative neuromodulation modalities, announced an addition to the company’s newest generation of Stimpod neuromuscular transmission monitor – the capability of utilizing either of the two most industry prominent types of monitoring sensors, AMG and EMG. The new Stimpod system and EMG sensor accessory will be exhibited at the American Society of Anesthesia (ASA) Annual Meeting, October 19-21 in Orlando, Florida alongside the company’s entire Stimpod portfolio for anesthesia.

“We are excited to announce the EMG modality to our Stimpod line of monitors,” stated Corlius Birkill, CEO of Xavant Technology. “By offering, for the first time, anesthesiologists and clinicians a choice in using either AMG or EMG, we can give them unparalleled clinical and budgetary benefits.” Mr. Birkill continued, “We believe quantitative or objective monitoring of patients who are undergoing neuromuscular block for surgery should be the standard of care. Our goal is to provide physicians with the most optimal and efficient tools to achieve that standard.”

The latest update to the AMG-based Stimpod NMS450X monitor series will enable the use for the first time ever, a dual sensor objective neuromuscular transmission monitor that enables anesthesiologists the choice of using either acceleromyography (AMG) with a reusable sensor or electromyography (EMG) with a disposable sensor to manage patients undergoing neuromuscular block during surgery or while being cared for in the intensive care unit.

By adding an EMG sensor accessory to the Stimpod, clinician opportunities in monitoring will be maximized. Being able to choose either AMG or EMG at site of service, hospitals can perform cost-effective entire-surgery monitoring with the platform that is optimal for that specific case. While AMG is a proven, accurate and cost-effective technology, the EMG sensor will simplify how clinicians monitor patients in more restrictive surgical cases, such as robotic surgery where restricting the hands is common. The EMG accessory is pending FDA clearance.

“The Stimpod NMT monitor is simple and economical way for hospitals to drive patient safety, Operating room, PACU, and ICU efficiency, and manage their very expensive paralytic and recovery drug budgets,” stated Xavant Chairman Roche van Rensburg. “We believe the data is fairly conclusive that hospitals can enhance safety outcomes related to residual neuromuscular block by utilizing objective NMT monitoring. But also important is the power to more effectively manage the time and cost-of-care efficacy for the hospital – we believe the Stimpod system can make a tremendous positive difference on both fronts,” added Mr. van Rensburg.

About Xavant Technology

By Xavant Technology October 17, 2019

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Novaerus NanoStrike Airborne Disinfection Technology

Novaerus NanoStrike Airborne Disinfection Technology

  • Table Top for Smaller Rooms ~120 sq. ft., NV200 delivers 50 CFM(Cubic Feet per Minute) airflow.
  • Wall Mountable, Pedestal Mounted or Roll Stand Mounted options for Medium Rooms ~900 sq. ft., NV900 delivers 150 CFM(Cubic Feet per Minute) airflow at fan speed 1 and 180 CFM at fan speed II.
  • Standalone for rapid remediation for larger common areas with a triple-stage Camfil filter, ~3,000 sq. ft., NV1050 delivers 533 CFM(Cubic Feet per Minute) airflow.
  • Novaerus NanoStrike Airborne Disinfection Technology protects against airborne viruses and bacteria. Nanostrike is the core, patented technology that uses Novaerus plasma-based technology killing all airborne microoganisms on contact providing protection against viruses and bacteria.

NanoStrike patented technology destroys viruses, microorganisms and bacteria at the DNA level:

  • Plasma coils create energy field that kills ALL germs and pathogens in sub-second time.
  • 99.9+% effective at eliminating Influenza pathogens, SARS-Cov-2(Covid-19), and MRSA
  • Kills ALL airborne microorganisms at the DNA level as small as 1 nanometer!
  • Total cell destruction ensures cells do not become viable as an infectious agent ever again.
  • Continuous 24/7 air disinfection and odor control with no disposables
  • Lowest cost of ownership operating 24/7 with no supplies needed for NV200 or NV900.
  • Plugs into standard power outlets plus wall mounts, pedestal stand or roll stand options
  • Independently tested and proven for use in ORs, ICUs, ED, Offices, Restaurants, etc.

 How does NanoStrike Protect?

NanoStrike utilizes an atmospheric plasma discharge like a lightning strike to kill and deactivate harmful airborne microoganisms.  NanoStrike plasma coils provide a deadly strike made up of multiple concurrent processes that work to rapidly destroy airborne pathogens.  The result is total destruction of all airborne pathogens! 

NanoStrike plasma coils create an electrostatic field bombarded by electroporation and electromagnetic field radiating heat and UV radiation in sub-second time to force cells down to one nanometer to explode with osmotic pressure resulting in total destruction of airborne pathogens. 

Novaerus does not filter virus and bacteria cells from the air it destroys them to the point of total destruction with no chance of reactivation or self-healing. 

NanoStrike can protect humans in hospitals, senior living facilities, long term care facilities, schools, locker rooms, casinos, railway stations, residences, hotel common areas, offices, manufacturing, meat processing plants and virtually any indoor environment where people gather.   

Breathe easy with Bell Medical and NanoStrike Technology.

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The Eyes are the Window to Your Soul

We all know this quote, but its origin is a little unclear. It has been attributed to William Shakespeare, Leonardo Da Vinci, the philosopher Cicero and even the bible.

Whatever the origins of this well-known quote, throughout history we have been aware that our eyes are incredibly precious organs. Not only do they allow us to see the world around us but through them we can tell what a person feels and thinks.

However, despite being aware that somehow our eyes are special, we have been a bit blasé about protecting them. Eye protection has evolved over time(1) via several different routes including:

  1. Combat – To lose an eye in battle and wear an eye patch was once considered an honour. The use of helmets did offer some protection. The use of gas during World War 1 resulted in gas masks with glass windows to protect the eyes from the deadly gas. More recently the rise of IEDs resulted in the percentage of combat causalities hospitalised due to ocular trauma increasing from 2% in 1914 to 13% in the 1990s Desert Storm conflict. In modern armies today eye protection is mandatory.
  2. Sports and Recreation – Jousting required the riders to wear helmets with visors, but eye injuries were common. King Henry II, the French-born King of England, suffered an eye injury during a jousting tournament in 1559.  The king had not fastened his visor upon returning to the arena and a splinter from his opponent’s lance entered his right orbit. Complications resulted in the death of ‘the young lion’ from his eye injury. His death significantly changed the respective roles of France and England and the course of Western civilisation and history. Recently, ice hockey, Baseball and Basketball were the first sports to embrace eye protection followed by Squash, Cricket Hockey and Lacrosse.
  3. Occupational Eye Injuries – The rise of industry in the late 19th century resulted in a huge increase in mining and metalwork. This led to a surge in corneal abrasions in miners, heat cataracts in foundry workers and arc eye in welders. Gradually, visors and goggles. . Gradually, improved understanding of the impact resistance of materials and the nature of hazards brought about improvements in visors and goggles in the workplace

Thankfully, mainly due to the rise of Health and Safety, eye protection is now mandatory in many workplaces. There is good reason why this is necessary. Thousands of workers suffer painful eye injuries each year around the world. Many are minor but around 10-20% result in partial or full blindness. Equally, we only have two eyes and whilst some parts of the eye can be transplanted, a complete eyeball transplant is not yet possible. So, we need to do everything we can to protect our eyes as much as we can.

The most common types of injuries are:

  • Invasion of foreign bodies – The eye/s may sometimes be invaded by small foreign particles (e.g. dust from manufacturing activities) which can cause irritation and inflammation. Chemical Eye Burns – Both highly acidic (pH <4) and highly alkaline (pH >10) substances are toxic to the eye and cause chemical eye burns if they come into contact with the surface of the eye. Such substances are commonly found in the workplace, for example in laboratory chemicals or industrial cleaning products.Penetrating Injuries – When an object pierces the eye, penetration occurs, and this can lead to loss of vision or blindness. Staples, nails and flying debris commonly cause this type of injury.Blunt trauma injuries – These are injuries which do not penetrate the skin and do not result in external bleeding.  The eye is struck by a heavy object and this can cause the eye to bleed internally.Allergic conjunctivitis – Is common amongst workers in the food handling and agricultural sectors who are regularly exposed to spices, fruits, and vegetables. Eye diseases associated with ultraviolet radiation exposure – Outdoor workers are often exposed to ultraviolet radiation (in the form of sunlight) in excessive quantities. Artificial sources of ultraviolet radiation are also found in a range of workplaces and can damage the eyes. These include welding arcs, germicidal lamps, and lasers. Computer use disorders – Using a computer for extended periods of time is associated with a range of temporary eye disorders including pain and altered vision.

Of course, when we go about our daily lives, we meet all sorts of people wearing eye protection. These can be construction site workers, the mechanic fixing your car, the gardener mowing your lawn, the person mending your shoes. Many jobs now take eye protection seriously.

Eye protection is also taken seriously even if you are unfortunate to be here –

However, can you guess by looking at these photographs what the problem is?

Where is the eye protection for the patient? Everyone else in theatre has eye protection so why not the patient? A nurse will take a roll of non-sterile tape that has been lying in theatre and tape your eyes. A piece of equipment could hit you in the eye or even someone’s elbow. You are the most vulnerable person in the room and yet nothing is done to protect your eyes from an infection, a corneal abrasion or even a trauma blow. Surely, if a gardener or a cobbler has eye protection then patients undergoing surgery should equally have their eyes protected.

References:

  1. Hoskin A.K, Mackey D.A, Agrawal R, Watson S. (2019). Eye Injuries across history and the evolution of eye protection. Acta Ophthalmologica, 97: 637–643.

Author: Niall Shannon, European Business Manager, Innovgas

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

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Measures to Control the Transmission of Covid-19

Ever since the first reports of Covid-19 in China (1) there has been a great deal of focus on how the virus spreads.

 It is now clear that, the virus causing COVID-19, is primarily transmitted between people through respiratory droplets and contact routes.

Droplet transmission occurs when a person is in close contact (within 1 m) of someone with respiratory symptoms (e.g. coughing or sneezing) and is therefore at risk of having their mucosae (mouth and nose) or conjunctiva (eyes) exposed to potentially infective respiratory droplets. Transmission may also occur through fomites in the immediate environment around the infected person. Therefore, transmission of the COVID-19 virus may occur by direct contact with infected people and indirect contact with surfaces in the immediate environment or with objects used on the infected person. (2) Studies from a variety of disciplines investigating viruses clearly support the following:

  • most respiratory and enteric viruses can survive on fomites and hands for varying lengths of time.
  •  fomites and hands can become contaminated with viruses from both natural and laboratory sources.
  •   viral transfer from fomites to hands is possible.
  •   hands come in contact with portals of entry for viral infection.

 If viruses remain viable on surfaces long enough to come into contact with a host, the virus may only need to be present in small numbers to infect the host. (3)

The virus can also be spread via airborne transmission which is different to droplet transmission. This refers to the presence of microbes within droplet nuclei. Droplet nuclei are generally considered to be particles ≤ 5μm in diameter that can remain in the air for longer periods of time and can be transmitted to others over distances greater than 1 metre. Airborne transmission of the COVID-19 virus is possible under circumstances and settings where aerosol generating procedures (AGPs) are performed. (2)

We are all aware of the measures that are being taken in the community to prevent the transmission of the virus via the droplet and contact routes. (4) But what is happening in hospitals; particularly when a patient needs emergency surgery or, as is now happening an elective or planned procedure?

In planned procedures the patient should isolate for several days and test negative for Covid-19 before entering theatre. Emergency patients are identified as symptomatic or asymptomatic and appropriate Infection Prevention and Control procedures are put in place. (5)

Much is being done in hospitals generally and more specifically in operating theatres to reduce transmission rates. While the rates of overall infection in a country may be below 1%, (6) in hospitals the rates could be anywhere between 5% and 15%. (7)

So, what more could be done in hospitals to bring the rates of infection down? In my opinion, whilst some effort is being made to reduce fomite spread of covid-19 in the operating theatre with regular disinfection and greater use of single use items, much more could be done. (8,9)

Rolls of medical tape are often to be found in the operating theatre. Studies have shown that 51 % of rolls of tape found lying around in theatre may have VRE or MRSA, so multiple resistant bacterial organisms on them, which we then apply to patients. (10) These rolls of tape may well have Covid-19 on them and if applied to the patient’s eyes may well infect them.

It would be far safer, and better practice to use our sterile, single use EyePro™ to cover the patient’s eyes (11) thereby removing a potential Covid-19 transmission route.

Many theatres make up their own bite blocks using gauze and rolls of tape on the anaesthetic trolley. All this activity carries a high risk of fomite transmission. If you use a single wrapped clean BiteMe™ with clean gloves, BiteMe™ should pose less risk compared to rolled up gauze with respect to viral transmission. (12)

Thus, by making two small changes to operating theatre procedures you could be doing so much more to reduce the potential transmission of Covid-19.

  • Use sterile single use EyePro™, the only sterile eyelid occlusion dressing available and stop using medical tape on your patient’s eyes.
  • Use single use, clean BiteMe™ as your bite block of choice and stop making your own bite blocks.

Dr Andrew Wallis

BSc., BMedSci., MBBS (hons), FANZCA

Private Anaesthetist

Member of Medical Advisory Committee, Calvary Hospital, Launceston, Tasmania.

Medical Director Innovgas Pty Ltd

References:

  1.  Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19). 16-24 February 2020. World Health Organisation.
  2.  Infection prevention and control during health care when coronavirus disease (COVID-19) is suspected or confirmed. Interim guidance 29 June 2020. World Health Organisation
  3. S. A. Boone* and C. P. Gerba. Significance of Fomites in the Spread of Respiratory and Enteric Viral Disease. Applied and Environmental Microbiology, Mar. 2007, p. 1687–1696.
  4. Transmission of SARS-CoV-2: implications for infection prevention precautions. Scientific brief 09 July 2020. World Health Organisation.
  5. Operating framework for urgent and planned services in hospital settings during COVID-19. 14 May 2020. NHS England.
  6. COVID-19 situation update for the EU/EEA and the UK, as of 14 July 2020. European Centre for Disease Prevention and Control.
  7. G. Iacobucci. Covid-19: Doctors sound alarm over hospital transmissions. BMJ 2020;369. 19 May 2020.
  8. Infection prevention and control and preparedness for COVID-19 in healthcare settings. Third update – 13 May 2020. European Centre for Disease Prevention and Control.
  9. COVID-19: infection prevention and control guidance. 21st May 2020. NHS England.
  10.  Harris PN et al. Adhesive tape in the health care setting: another high-risk fomite? Med J Aust. z2012;196(1):34.
  11.  EyePro™ Brochure.
  12.  BiteMe™ Brochure.
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Why Quantitative NMT Monitoring is Critical in Surgical Patients and How Best to Do It

Some sort of assessment of neuromuscular transmission (NMT) is necessary in surgical patients by clinicians and anesthetists to get a feel for the depth of anesthesia. This assessment can be done using simple yet subjective clinical parameters or through more advanced and objective monitoring devices. NMT monitoring is required to

  • ascertain that anesthesia is appropriate for tracheal intubation
  • check the adequacy of neuromuscular blockade during a procedure
  • determine the need for adjusting the dose of neuromuscular blocking agents (NMBAs)
  • decide the timing and dose of reversal agents
  • ensure full patient recovery before extubation

When NMT monitoring is absent, inadequate, or inaccurate, it is associated with an increased risk of

  • aspiration
  • airway obstruction
  • adverse respiratory events
  • pharyngeal dysfunction
  • prolonged post-anesthesia stays
  • unpleasant postoperative symptoms including muscle weakness

Almost 40% of patients have incomplete neuromuscular recovery in the early recovery period from anesthesia

Having said that, it may come as a surprise that anesthesiologists often overlook the importance of effective monitoring. Research reveals that less than 40% of patients receive subjective assessment using nerve stimulators, while objective monitoring is performed in only 17% of patients. Furthermore, almost 40% of patients have incomplete neuromuscular recovery in the early recovery period from anesthesia. Against this backdrop, it is easy to understand why proper NMT monitoring is the need of the hour in surgical patients. We will now discuss how such monitoring can be achieved.

Current Approaches to NMT Monitoring

There are three ways to monitor the neuromuscular status:

  1. Clinical assessment—most commonly employed by clinicians, it is a subjective evaluation of clinical parameters such as respiratory measures and muscle function. However, none of the tests has a sensitivity greater than 0.35 or positive predictive value more than 0.52. Clearly, it’s not the most reliable approach.
  2. Qualitative monitoring/peripheral nerve stimulation—Qualitative monitoring uses peripheral nerve stimulators (PNSs). The evoked response of the stimulated muscle is then assessed visually or tactilely. It’s more reliable than a simple clinical assessment but less so than quantitative monitoring.
  3. Quantitative monitoring—this involves the use of devices that quantify the NMT blockade and display the measurements numerically. Quantitative monitoring offers the virtues of reliability, accuracy, and objectivity. We describe quantitative monitoring in more detail below.

Why Quantitative Monitoring is the Way to Go

Following are just some of the benefits of quantitative neuromuscular monitoring:

  • Objective measurements—stimulation is provided to a suitable muscle and the evoked response is quantified objectively. It can be through measuring the action potentials generated within the muscle, the strength of its contraction, or even the crackling sounds associated with muscle movement. Whichever the underlying mechanism for the monitoring device, nothing is left to the subjective opinion of the clinician. Hence, the results are consistent and reproducible.
  • Display of results—quantitative monitoring devices are smart and internally compute any raw data to display final results in numerical form that can then be used to guide clinical decision-making.
  • Automatic processes—most devices just need their leads to be attached at the appropriate locations and then they do the rest themselves, including providing stimuli, recording responses, computing results, and displaying the same. Modern devices also require no calibration.
  • Risk of PRNB nearly eliminated—the risk of postoperative residual neuromuscular blockade (PRNB) is almost completely eliminated with the use of quantitative monitors for tracheal extubation.

Quantitative NMT Monitoring Devices

There are several methods to perform quantitative NMT monitoring:

Modern quantitative NMT monitoring devices are capable of automatically providing stimulation to the muscle and recording and interpreting the response. The impulses can be given in various patterns such as train of four (TOF), double-burst (DBS), tetanic and post-tetanic count (PTC), which can be used to determine the train-of-four count (TOFC) or the degree of fade. The evoked muscle response can then be measured by using different scientific techniques giving rise to several types of devices:

  1. Mechanomyography (MMG)—the device detects muscle isometric force of contraction and converts it into an electrical signal. The amplitude of the signal reflects contraction strength.
  2. Electromyography (EMG)—it records compound muscle action potentials generated in the muscle and this electrical activity is proportional to the contraction force.
  3. Acceleromyography (AMG)—the monitor measures muscle acceleration via a piezoelectric sensor. The piezoelectric crystal generates voltage when it is put into motion due to muscle contraction.
  4. Kinemyography (KMG)—such devices quantify muscle movement via a motion sensor strip. The strip once again contains piezoelectric sensors.
  5. Phonomyography (PMG)—it calculates muscle response based on sounds picked up a by microphone. This is possible because muscle contraction produces low-frequency sounds.

Decades of research demonstrate that AMG technology can detect residual paralysis in 97% of patients.

While the above seem some fantastic methods to quantitatively monitor NMT blockade in clinical settings, MMG and PMG monitors are not commercially available and only used for research purposes, there is only one EMG monitor available for commercial use but it’s not standalone, and studies comparing KMG to MMG (the “gold standard”) have found its data to have a large bias and it cannot be used interchangeably. In the end, the AMG technology has been the most successful for commercial and clinical deployment. The Stimpod NMS 450X is a classic example of a cutting-edge AMG monitor.

Why the Stimpod NMS 450X is the Monitor of Choice for Quantitative NMT Monitoring

There are many features that make the Stimpod NMS 450X the monitor of choice for quantitative neuromuscular transmission monitoring. You can review these features in detail here. We will go over some of the more pertinent features of this device in light of what we have discussed so far about neuromuscular monitoring:

Stimpod NMS450X Neuromuscular Patient Monitor

The Stimpod NMS450X reduces the incidence of residual paralysis in 97% of patients

  • Global coverage—There is no point in reading up about the importance of NMT monitoring and researching a monitor only to find that either it’s not commercially manufactured or it’s not available in your area. Xavant’s worldwide coverage ensures Stimpod’s availability across the globe. In his comprehensive review article covering NMT monitoring in the perioperative period, Dr. Glenn Murphy, a senior anesthesiologist affiliated with the NorthShore University HealthSystem, points out, “At the present time, only one stand-alone portable device is available in the United States, the STIMPOD (Xavant Technologies, Pretoria, South Africa).”
  • Fully automated—The Stimpod NMS 450X’s OneTouch NMT™ technology allows users to monitor an entire case from electrode placement to extubation by pressing a single button. The device automatically verifies optimal electrode placement, provides the appropriate supramaximal current, begins TOF monitoring and moves to PTC when a deep block is reached. Upon reversal, it automatically reinitiates monitoring until the patient is 90%+ recovered.
  • 3D AMG transducer—The Stimpod NMS 450X uses a 3D AMG transducer which is most effective in capturing the full force of muscle contraction. In his seminal article, Dr. Murphy observes, “An important disadvantage of first-generation AMG monitors … is that acceleration of a muscle following nerve stimulation is only measured in a single direction (perpendicular to the face of the transducer). However, stimulation of the ulnar nerve results in isotonic contractions of the adductor pollicis that are often in three dimensions, involving three joints, frictional forces, and deformation of tissues.”

Decades of research demonstrate that AMG technology can detect residual paralysis in 97% of patients. The Stimpod NMS450X is an embodiment of that technology and an all-in-one solution for neuromuscular monitoring. Please contact us to know more about NMT monitoring, train of four monitoring and our solutions.

References

Murphy GS. Neuromuscular monitoring in the perioperative period. Anesth Analg. 2018;126:464–468.
Duţu M, Ivaşcu R, Tudorache O, et al. Neuromuscular monitoring: an update. Rom J Anaesth Intensive Care. 2018;25(1):55–60. doi:10.21454/rjaic.7518.251.nrm

Thilen SR, Bhananker SM. Qualitative Neuromuscular Monitoring: How to Optimize the Use of a Peripheral Nerve Stimulator to Reduce the Risk of Residual Neuromuscular Blockade. Curr Anesthesiol Rep. 2016;6:164–169. doi:10.1007/s40140-016-0155-8

Hemmerling TM, Le N. Brief review: Neuromuscular monitoring: an update for the clinician. Canadian Journal of Anesthesia. 2007;54(1):58-72.

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The Cost of Postoperative Respiratory Adverse Events

Respiratory impairment following general anaesthesia can pose a significant problem. Adverse and critical respiratory events (AREs and CREs) have been responsible for increased morbidity and mortality. The main cause of AREs after surgery is related to the use of neuromuscular blockers (NMBAs) during general anaesthesia. The action of NMBAs might not cease completely at the end of the procedure, leading to residual muscle paralysis. Postoperative residual neuromuscular blockade, aka postoperative residual curarization (PORC), ranks among the top three critical events in the post-anesthesia care unit (PACU) that require emergency intervention.1 It has been estimated that approximately 40% of the patients brought to the PACU have residual blockages.2 Apart from the obvious effects on patients’ life and health, AREs can have other consequences. Caregivers have to undergo increased physical and emotional stress, which can affect delivery of care to other patients in the PACU. Financial costs can increase for both patients and hospitals as substantial critical care resources are devoted to solving such problems.

How big is the problem of residual neuromuscular blockade?

Muscle paralysis is estimated using a clinical tool called train-of-four ratio (TOFR). Residual neuromuscular blockade is believed to have significant clinical effects if the TOFR goes below 0.9.3 With just a single dose of intermediate acting NMBAs, it has been shown that up to 45% of patients can have residual blockade (TOFR < 0.9).4 Lower TOFRs have been associated with increased risk of CREs. This was demonstrated by Murphy et al, who collected data of over 7400 patients who had received general anaesthesia.5 They found that the incidence of critical respiratory events in this group of patients due to residual blockade was 0.8%. Based on these statistics, Brull et al estimated that each year about 81,000 people in the United States and almost 0.5 million people worldwide experience CREs after general anaesthesia.2

What is the main cause of CRE after surgery?

It was shown that the incidence of CREs was higher by 50% in patients who had TOFR less than 0.76

While there can be several causes of CRE, a large proportion of cases have been associated with residual neuromuscular blockade. In one study by Bissenger et al, it was shown that the incidence of CREs was higher by 50% in patients who had TOFR less than 0.7.6 In a separate case-control study, Murphy et al compared TOFRs in patients who had developed CREs and controls who did not have CREs. They showed that while patients in the control group had TOFRs above 0.7, 78.3% of patients who had CREs had TOFRs that were below 0.7.3 Xara et al also investigated the determinants of AREs in 340 patients who underwent surgery. They found that patients who were administered NMBAs during the surgical procedure had increased incidence of AREs (79%) as compared to those who did not receive them (55%).7 They also noted that the incidence of ARE was increased in patients who had received neostigmine. Grosse-Sundrup et al showed that the use of intermediate NMBAs increased the risk of postoperative desaturation and re-intubation.8

What are the costs involved?

Residual neuromuscular blockade can cause upper airway obstruction, aspiration and pharyngeal dysfunction. These situations may require emergency intervention in the form of re-intubation and positive pressure ventilation. The costs associated with these interventions can be considerable. Patients who develop respiratory complications after surgery generally often have to be hospitalised for longer, which increases costs.

The cost of treatment for patients with respiratory complications was $62,000, compared to $5000 without complications, with an additional 92,000 more ICU admissions per year10

Zhan et al found that postoperative respiratory failure (that did not include pulmonary embolism) increased hospital stay by nine additional days, and translated to an additional $53,000 in healthcare costs.9

A report developed by the National Surgical Quality improvement program showed that patients with respiratory complications stayed at the hospital for at least 14 days longer vs. those who did not have these complications.10 The same report estimated the cost of treatment for patients with respiratory complications was around $62,000, while those without such complications were set back by a mere $5,000 in comparison. On a national level, pulmonary complications after surgery lead to 92,000 more ICU admissions per year, which alone imposes a burden of $3.42 billion annually.

What is the best way to deal with the situation?

Residual neuromuscular blockade can be avoided by monitoring neuromuscular status during the surgical procedure. If neuromuscular function is allowed to return to optimal levels prior to extubating the patient, chances of residual blockade in the PACU decrease. Ideally, the anaesthetist should be able to monitor the TOFR, so that it may be allowed to reach the critical threshold of 0.9 prior to extubation.

What kind of monitoring works best?

Severe hypoxaemia occurred in 21.1% of patients in the conventional group but in none of the patients in the acceleromyography group11

There are three methods to monitor neuromuscular function—clinical, qualitative monitoring and quantitative monitoring. Clinical methods (such as head-lift and grip-strength tests) have low sensitivity and specificity, and are not really suited for patients prior to extubation. Qualitative evaluation using peripheral nerve stimulators is a common practice. However, it involves subjective assessment of TOFR and studies have shown that TOFRs above 0.4 may not be effectively detected by this method. Quantitative (or objective) methods of calculating TOFR, using techniques such as mechanomyography, electromyography and acceleromyography, have proven more effective. Murphy et al assessed the risk of residual neuromuscular blockade and AREs in patients who were monitored by both qualitative and quantitative means.11 Patients were randomised for NMB monitoring using either conventional peripheral nerve stimulators or acceleromyography. Residual NMBs in the PACU were documented in 30% of patients in the conventional group and only 4.5% of patients in the acceleromyography group. More significantly, severe hypoxaemia occurred in 21.1% of patients in the conventional group but in none of the patients in the acceleromyography group.

The bottom line is this: quantitative neuromuscular transmission monitoring has the potential to reduce residual blockades, decrease CRE risk, and reduce costs.

Stimpod NMS450X Neuromuscular Transmission Monitor

The Stimpod NMS450X Neuromuscular Transmission Monitor

The Stimpod NMS450X is a standalone neuromuscular transmission monitor that can easily be integrated into the anaesthetic setup. During reversal of neuromuscular blockade, the monitor automatically initiates TOFR monitoring, which continues until recovery is complete. Its portable design makes it easy to shift between the OR and PACU, and it can easily be attached to the IV pole. Its economical pricing and proven efficacy make it a sensible investment for hospitals who wish to make optimum use of resources and cut costs in the long term. For more details, visit xavant.com or request a quotation.

References

  1. Strauss P, Lewis M. Identifying and Treating Postanesthesia Emergencies. Or Nurse. 2015 Nov 1;9(6):24-30.
  2. Brull, S. J., & Kopman, A. F. Current Status of Neuromuscular Reversal and Monitoring: Challenges and Opportunities. Anesthesiology 2017; 126(1): 173-90.
  3. Murphy GS, Szokol JW, Avram MJ, et al. Postoperative Residual Neuromuscular Blockade is Associated with Impaired Clinical Recovery. Anesth Analg. 2013;117(1):133–141
  4. Debaene B, Plaud B, Dilly MP, Donati F. Residual Paralysis in the PACU After a Single Intubating Dose of Nondepolarizing Muscle Relaxant with an Intermediate Duration of Action. Anesthesiology 2003;98: 1042–8
  5. Murphy GS, Szokol JW, Marymont JH, Greenberg SB, Avram MJ, Vender JS: Residual Neuromuscular Blockade and Critical Respiratory Events in the Postanesthesia Care Unit. Anesth Analg 2008; 107:130–7
  6. Bissinger U, Schimek F, Lenz G. Postoperative Residual Paralysis and Respiratory Status: A Comparative Study of Pancuronium and Vecuronium. Physiol Res/Acad Sci Bohemoslovaca. 2000; 49(4):455–462
  7. Xará D, Santos A, Abelha F. Adverse Respiratory Events in a Post-anesthesia Care Unit. Archivos de Bronconeumología (English Edition). 2015 Feb 1;51(2):69-75.
  8. Grosse-Sundrup M, Henneman JP, Sandberg WS, et al. Intermediate Acting Non-depolarizing Neuromuscular Blocking Agents and Risk of Postoperative Respiratory Complications: Prospective Propensity Score Matched Cohort Study. BMJ. 2012;345:6329.
  9. Zhan C, Miller MR: Excess Length of Stay, Charges, and Mortality Attributable to Medical Injuries During Hospitalization. JAMA 2003; 290: 1868–1874
  10. Dimick JB, Chen SL, Taheri PA, Henderson WG, Khuri SF, Campbell DA. Hospital Costs Associated with Surgical Complications: A Report from the Private-sector National Surgical Quality Improvement Program. J Am Coll Surg. 2004;199(4):531–537
  11. Murphy GS, Szokol JW, Marymont JH, Greenberg SB, Avram MJ, Vender JS, Nisman M. Intraoperative Acceleromyographic Monitoring Reduces the Risk of Residual Meeting Abstracts and Adverse Respiratory Events in the Postanesthesia Care Unit. Anesthesiology: The Journal of the American Society of Anesthesiologists. 2008 Sep 1;109(3):389-98.