Charles Durbin, MD, professor of anesthesiology and surgery, University of Virginia, Charlottesville, describes a difficult airway management case that left his patient feeling fine but gave him heart palpitations.
“About 15 years ago, I did an emergency cricothyrotomy on a patient [during which] the tube stopped sealing. The resident performed a laryngoscopy. We took the tube out but couldn’t see anything. We tried to ventilate for about 5 minutes, but couldn’t pass gas. The patient’s saturations were falling. The patient was fine afterwards, but my heart rate was pretty high,” he explains.
Durbin’s story illustrates the challenges of managing difficult airways, common among obese patients, neonates, young children, and men with beards. The ability of respiratory therapists to manage difficult airways impacts the quality of anesthesia delivery and success of patient outcomes.
What Is a Difficult Airway?
“Practice Guidelines for Management of the Difficult Airway,” published by the American Society of Anesthesiologists (ASA), defines a difficult airway as “the clinical situation in which a conventionally trained anesthesiologist experiences difficulty with face mask ventilation of the upper airway, difficulty with tracheal intubation or both. The difficult airway represents a complex interaction between patient factors, the clinical setting and the skills of the practitioner,” it adds.
Mark Grzeskowiak, RRT, manager of education and quality, Long Beach Memorial Medical Center, Long Beach, Calif, says some practitioners define difficult airway management by the number of intubation attempts. He thinks the quality of available technology plays an important role in airway management, saying, “If you’ve got the world’s greatest equipment at your disposal, then difficult may not be so difficult.”
Durbin says airway management includes a range of respiratory services. He says, “It’s important to distinguish managing a difficult airway from placing an endotracheal tube.
“People who don’t work in the operating room think that managing the patient [is just] placing the endotracheal tube. It also includes oxygenating the patient, removing CO2, and preparing to intubate. If you intubate a patient who hasn’t been adequately ventilated, the delay in providing oxygen can produce a bad outcome, such as brain injury,” he warns.
Durbin says factors that determine the degree of airway management difficulty include the visibility of the pharynx, ease of jaw movement, and side-to-side neck mobility. “If you have problems with one, you have a 5% chance of difficulty; two, a 20% chance; and three, a 30% chance of difficult intubation,” he observes.
Difficult Airway Management Cases
Durbin says patients immobilized by halo traction devices present the greatest challenges to airway management. “These folks are fine when they’re awake, but upon induction of anesthesia, they lose their airway and stop breathing. When you put them to sleep, you can’t ventilate or intubate them,” he says.
Durbin also notes the problems posed by facial hair on men, saying, “A full beard caused more difficulty during patient ventilation than predicted [in studies].”
Grzeskowiak says craniofacial conditions—such as Pierre Robin or Apert’s syndrome and a predisposition toward laryngeal webs (multiple strands of tissue that connect one side of the airway to the other)—make intubation of pediatric patients difficult, as can the disproportionate size of a child’s tongue and tonsils, which can block airways. Grzeskowiak, who notes that infants receiving anesthesia suffer higher rates of mortality and morbidity than adults, describes the challenges of intubating babies.
“The voice box is relatively small and located higher in the neck. The higher up the larynx, the harder it is to see. When you lay them on their backs, [the voice box] is in an anterior position and harder to put a tube through,” he explains.
Pediatric ventilation also poses problems for children, who lack the oxygen reserves of adults, says Grzeskowiak. “If you’re trying to perform bag and mask ventilation on a little kid, it’s far easier to fill their stomachs with air than [it is in] adults. If you distend a baby’s stomach, their diaphragm doesn’t move and the resting lung volumes get smaller, putting [the infant] at greater risk for vomiting and aspiration,” he explains.
Pediatric management of difficult airways may require a strategy other than “a primary approach,” state the practice guidelines. Durbin, who says, “You can’t reason with children age 2 to 10,” recommends the “judicious use of inhalation anesthesia” for young children. “A neonate in respiratory distress needs a mask or endotracheal tube,” he says.
Obesity and Obstructive Sleep Apnea
According to the Obesity Action Coalition (OAC), an advocacy organization based in Tampa, Fla, 93 million Americans are obese with body mass indexes (BMI) of 30 or more. The OAC expects this number to rise to 120 million over the next 5 years.
Grzeskowiak says, “As our population’s waistlines change, so [do] their neck sizes. The extra fat around their necks makes it difficult to position [obese patients] properly for intubation. Once the laryngoscopes are in their mouths, the pharynxes are frequently full of excess tissue, which makes it difficult to find the anatomical landmarks you need to guide you to the trachea. If you use conventional equipment, there’s more physical force required because there’s more tissue to move around.”
Durbin says intubation of patients with morbid obesity (MO) “may require head and trunk elevation and large laryngoscope blades,” but “is rarely difficult.” He says mask fit and manual ventilation can pose problems for MO patients.
Grzeskowiak agrees. He says, “Most people think MO patients are difficult to intubate, but it may be difficult to hold a mask on their face. You might have the wrong size mask, or it may be difficult to make it seal around the contours of the face.”
According to the OAC, patients with MO, or a BMI of 40% or more, have disproportionate rates of comorbidities, such as obstructive sleep apnea (OSA). Durbin recommends preoperative screening and sleep studies to determine the severity of the disorder in patients, who should avoid respiratory depressants.
“Continuous positive airway pressure or bilevel positive airway pressure should be considered postoperatively, at home, or in the hospital. Admission to the hospital for all but minor procedures should be considered in OSA patients,” he explains.
Adverse outcomes associated with difficult airway management include death, brain injury, cardiopulmonary arrest, unnecessary tracheostomy, airway trauma, and damage to teeth, state the guidelines. Grzeskowiak says, “The more difficult the airway management, the more likely [adverse events] are to occur.”
Durbin calls death, cardiac arrest, and brain injury rare events, but says tooth damage represents “the most common outcome for which anesthesiologists must pay money. We probably see a tooth injury once every 2 or 3 weeks in my practice of 35 operating areas,” he adds.
Indeed, “Dental Trauma in Anesthesia,” published in the Canadian Journal of Anesthesia, states that dental trauma is the largest single reason for successful malpractice claims against anesthetists. Durbin says tooth damage occurs most frequently among patients with poor dentition. He warns his patients that tooth damage might occur during intubation.
Preventing Adverse Outcomes
Durbin says RTs need to know how to perform emergency airway procedures, such as tracheotomies, to prevent adverse events, such as death, cardiac arrest, and brain injury. He advises RTs to measure blood and oxygen saturation levels with a pulse oximeter, saying, “Patients don’t get brain injury from hypoxemia, but when the heart stops. If you wait until the point when the heart is declining, which is common in children, you’ve probably missed your chance to intervene,” he adds.
Grzeskowiak recommends keeping a difficult airway cart (DAC) on hand to prevent adverse events from becoming airway emergencies. “We have DACs in our adult ICU, CCU, pediatric ICU, and emergency department. The first year we used the carts 85 times. Sometimes we push [a cart] in the room just in case. One time we used everything on it,” he says.
Durbin feels that RTs need more training with mask management to prevent adverse reactions to anesthesia. He says, “We’ve de-emphasized mask management. People have difficulty with those skills because they haven’t been practiced in difficult patients.”
“In my training,” he adds, “I had to provide mask anesthesia that didn’t require intubation for surgery. When you do that in training, you learn little things that make [airway management] easier and more successful.”
Grzeskowiak advises RTs to diversify their skill set and learn to use alternate airway devices to accommodate different types of patients. He says, “Most people want to dance with the one who brought them,” a reference to the habit of RTs to use the intubation device with which they are most familiar.
Durbin advises RTs to choose the alternate intubation device with which they are most comfortable, saying, “If you’ve never used a fiber-optic scope, it’s probably not a good strategy to use it on a patient who’s going to be difficult. On the other hand, if you’ve used an indirect laryngoscope, you’d want to have that as your secondary technique,” he adds.
Grzeskowiak thinks a team approach can minimize adverse outcomes. He suggests adopting the crew resource management principles used by the airline industry to foster collaboration and cross-training during airway management.
Durbin says, “You might want to have a backup person available with a different skill set. So, when you run out of choices, there’s another choice available. If you’re in the middle of a procedure and you’re having trouble, you should call for help,” he stresses.
Difficult Airway Management Strategy
“Practice Guidelines for Management of the Difficult Airway” suggests developing a preformulated strategy to accommodate intubation and extubation of difficult airway management cases. The guidelines state, “The degree of benefit for any specific strategy cannot be determined, [but] a preplanned strategy may lead to improved outcomes.”
Grzeskowiak endorses this approach, saying, “We have found that [a preformulated airway management strategy] is pretty important.”
Development of a strategy depends, in part, on the anticipated surgery, condition of the patient, and skills and preferences of the anesthesiologist, state the guidelines.
Durbin says, “You should be prepared to deal with the same problems you started with. If you struggled on the way in, you probably want to do additional tests, such as cuff leak tests to measure the pressure at which the gas passes the tube.”
“Practice Guidelines for Management of the Difficult Airway” strives to improve management of difficult airways and reduce the incidence of adverse outcomes. Grzeskowiak recommends using a couple of strategies for difficult airway cases. He believes that a proactive approach can mitigate complications related to patient care, saying, “If you plan for the worse, everything goes better.”
Sherree Geyer is a contributing writer for RT. For further information, contact [email protected].
- Practice guidelines for the management of the difficult airway. Available at: www.anesthesiadoc.net/. Accessed August 1, 2008.
- All about obesity. Available at: www.obesityaction.org/aboutobesity/index.php. Accessed August 1, 2008.
- Clokie C, Metcalf I, Holland A. Dental trauma in anesthesia. Available at: www.cja-jca.org/cgi/content/abstract/36/6/675. Accessed August 1, 2008.