LEARNING Objectives
>> Learn about the various devices available to effectively suction the airway.
>> Understand the critical importance of preventing airway aspiration.
>> Recognize some of the new techniques in airway suctioning.
KEY Terms
Aspiration: The act of inhaling foreign material or emesis into the lungs.
Aspiration pneumonia: Infection of the lung caused by inhalation of oral secretions and foreign material that contain infectious bacteria.
Aspiration pneumonitis: Chemical injury to the lung caused by inhalation of sterile gastric contents or other foreign material.
Few situations in medicine are more high-stakes than management of the unstable airway. Failure to protect a patient’s airway can result in life-threatening hypoxia, aspiration and hemodynamic compromise in only a matter of minutes. A common threat to a patient’s airway in the prehospital setting is rapidly accumulating fluid such as airway secretions, blood, vomit and other foreign material. For EMS providers, few situations are more technically challenging than managing these unstable airways in the dynamic, dimly lit, confined spaces frequently encountered in the prehospital setting.
Despite this reality, outside of initial EMT training, EMS providers rarely train on the art of airway suctioning or discuss its critical importance to the patient both in the immediate prehospital setting as well as in the following days and weeks. In addition, many EMS agencies don’t routinely take their portable suction units patient-side, potentially causing a delay in successfully managing the airway should this valuable tool need to be retrieved from a responding apparatus.
Furthermore, both experience and some published literature suggest that because EMS suction units are infrequently used, they’re also infrequently inspected, resulting in the potential for mechanical failure when needed.1
Lastly, in recent years, ACLS guidelines have refocused rescuers on the importance of delivering high-quality chest compressions and early defibrillation while placing less emphasis on the immediate need for endotracheal (ET) intubation during cardiac arrest management.2 The reasons for these procedural changes are multifactorial and beyond the scope of this article. However, with an increasing utilization of supraglottic airways and bag-valve mask (BVM) ventilation during cardiac arrests, providers are potentially encountering unprotected airways more frequently and managing them for longer periods of time.
SUCTION EQUIPMENT
Prehospital suction units fall into two categories:portable and vehicle mounted. Both types depend on essentially the same components: catheters and tubing, collection canister and ability to create a vacuum, typically with a positive displacement pump and power source. Each of these components are integral in creating suction and thus must be checked each shift and after every use, in order to be considered response-ready. Each component, if not properly cared for, can become the weak link that renders your suction unit useless during the exact moment your patient needs it most.
Required suction unit checks should be clearly spelled out in department policies and procedures. Documentation they’ve been checked is your best defense if a unit fails to operate. At a minimum, a quick 10-second system check can be conducted by following these simple steps: unplug the suction unit from the onboard charging system, pinch the distal end of the large bore suction tubing, turn the unit on while listening for the distinct sound of the motor being put under a load. This quick check provides the following:
1. The tubing is connected properly and the integrity of the tubing hasn’t been compromised by a significant crack or break;
2. The canister and lid are maintaining an airtight seal;
3. The motor is functioning properly (see your manufacturer specifications for the vacuum pressure your device should be able to achieve); and
4. The batteries are charged and connected correctly.
It’s important to note that this quick shift check doesn’t replace the manufacturer’s suggested bench tests and maintenance schedule. In addition, providers should check to ensure responding apparatus have manufacturer-sealed spare tubing and suction catheters in the event replacements are needed on scene. Lastly, agencies should be prepared with appropriate equipment and training to rapidly suction a variety of very different airways and airway devices from ET tubes to supraglottic airways to tracheostomies.
HONEST EXPERIENCES SHARED
The San Diego Fire Department (SDFD) recently performed a 12-month audit of over 700 intubations. Within a few minutes of completing the advanced airway call, EMS staff conducted a telephone interview with the paramedics who were involved in the intubation. This audit and following policies resulted in a reduction of the department’s rate of unrecognized esophageal intubations from 18 per year to zero. A surprising finding during this audit was that a number of paramedics admitted the suction unit wasn’t initially brought to the patient’s side on scene. In most cases, the suction unit wasn’t retrieved until the need for suction was realized. Why is that?
Emergency providers tend to be action oriented with a focus on solving the immediate problems right in front of them. In these critical situations, the focus is often “just get the tube.” After all, who hasn’t successfully intubated with at least some secretions in the oral pharynx? However, as the practice of EMS medicine advances in capabilities and its importance to the patient’s long-term care grows in recognition, EMS providers must be aware of the potential complications that can occur in the hours and days that follow. Thus, perhaps the focus shouldn’t only be on “getting the tube,” but also on efficiently securing a “clean airway” when possible. With this added attention, maybe we can help our patients avoid serious complications that lie just around the corner.
We don’t need more studies or data to tell us when we need to take our suction unit patientside. It’s simple: if the patient were your mom or dad, would you take your suction? Wherever your airway equipment goes, your portable suction unit should tag along.
ASPIRATION
Aspiration occurs when foreign matter enters into the airways and lungs.3 Aspiration of small amounts of material is a relatively common occurrence, with one study demonstrating that 50% of healthy subjects aspirate airway secretions during routine sleep.4 However, in the ill and injured, aspiration can result in very serious consequences depending on the type, volume and acidity of the material aspirated. In addition, the frequency of aspiration events and the patient’s ability to tolerate these incidents will greatly affect overall patient outcomes.
Aspiration commonly stimulates protective airway reflexes, causing the patient to begin coughing or gagging; however, this isn’t always the case–this is termed “silent aspiration.” In one study, aspiration was suspected in only 9% of patients in whom aspiration was later confirmed.5 Although aspiration may be difficult to clinically diagnose in some patients, all EMS providers should recognize those patients who are at increased risk for such events and thus who require more careful airway monitoring and aggressive preventive suctioning on scene and during transport. (See Table 1.)
The possible complications of aspiration are numerous and range from a persistent cough and vocal cord dysfunction to rapidly progressive respiratory failure and death. (See Table 2) In the immediate prehospital setting, the SDFD paramedic rapid sequence intubation trial found that patients who aspirated prior to intubation required more intubation attempts, had a higher incidence of oxygen desaturation, and had lower pre- and post-intubation pulse oximetry values.6 For the long-term care of these patients, two aspiration-related syndromes are particularly notable: aspiration pneumonitis and aspiration pneumonia.
Aspiration pneumonitis refers to acute lung injury occurring after inhaling a large volume of regurgitated gastric contents.7 Because of the extreme acidity of gastric contents, chemical lung injury can occur rapidly. A superimposed bacterial infection may develop later depending on the bacteria within the gastric contents. Aspiration pneumonitis typically presents with acute shortness of breath, coughing and wheezing. Over the course of just a few hours, hypoxemia and hypotension can rapidly develop, ultimately progressing to acute respiratory distress syndrome (ARDS). Management of aspiration pneumonitis is mainly supportive, including aggressive suctioning/removal of the aspirated material if possible and providing adequate supplemental oxygen as necessary.
Aspiration pneumonia is a lung infection that occurs as a result of pathologic organisms entering into the lungs from the mouth and upper airway.7 Although aspiration pneumonia accounts for only 5—15% of all pneumonias, patients with aspiration pneumonia are more likely to be admitted to the intensive care unit and are more likely to die than patients with other types of community-acquired pneumonias.8 Aspiration pneumonia typically presents with a productive sputum cough, shortness of breath and fever evolving over several days to weeks. It’s important to note that aspiration pneumonia frequently occurs as a result of a silent aspiration and often without the patient being aware aspiration has occurred.3 If there’s a delay in diagnosing and treating aspiration pneumonia, it can result in formation of a lung abscess or even emphyema (purulent infection in the pleural space lining the outside of the lung). Management of aspiration pneumonia, as with any potentially septic patient, focuses on early antibiotic administration, fluid resuscitation, and maximizing oxygenation. (See “Infection Inspection: Screening & managing sepsis in the prehospital setting,” by Keith Widmeier, NREMT-P, CCEMT-P, EMS-I & Keith Wesley, MD, FACEP, in the March 2014 issue of JEMS.)
INNOVATIVE TECHNIQUES
In recent years, a number of innovative techniques to enhance airway suctioning and thus improve overall airway management have been described in a variety of online education forums. Three of these are briefly described here. EMS providers are encouraged to evaluate these techniques with their own agency leaders and medical director prior to application.
The first is the suction assisted laryngoscopy airway decontamination (SALAD) technique. Originally described by anesthesiologist James DuCanto, MD, this approach to airway management is particularly useful if uncontrolled vomiting is threatening your patient’s airway during attempts at intubation. The cornerstone of SALAD is using a rigid suction catheter in all phases of laryngoscopy to facilitate successful intubation. A provider places the suction catheter in the mouth and hypopharynx to decontaminate the airway before insertion of the laryngoscope (this is particularly important if using video laryngoscopy). The laryngoscope is then placed into the airway and the suction catheter is deliberately advanced into the opening of the esophagus to provide continuous drainage. The suction catheter is then maneuvered behind the laryngoscope handle and lodged into the left corner of the mouth to allow traditional ET tube placement from the right corner of the mouth.
A second innovative idea is that of “outsourcing suction.” With uncontrolled airway hemorrhage or persistent emesis, frequently the situation will occur where the intubator can suction the airway and obtain the necessary view of the vocal cords. However, upon stopping suctioning efforts to place the ET tube, blood rapidly re-accumulates in the airway, again obstructing the necessary view of the vocal cords. To overcome this, assign a second provider to maintain continuous suction in the oropharynx throughout the entire intubation attempt. In other words, “outsource” the task of suctioning to a colleague while you place the ET tube. This can be done from both sides of the mouth as resources and equipment allow.9 This team approach to airway management is facilitated by utilization of video laryngoscopy as all team members share the same view of the airway and thus the obstacles to successful intubation.
A third idea is transforming the ET tube into a large bore suction catheter. Described by emergency physician and intensivist Scott Weingart, MD, this method involves attaching a neonatal meconium aspirator to the end of the ET tube, which allows for continuous removal of airway fluids throughout ET tube placement.10 There are some possible EMS operational limitations to this method and some possible long-term clinical ramifications, but this technique does seem to offer the potential to improve airway visualization.
SUCCESSFUL VIDEO LARYNGOSCOPY
EMS use of video laryngoscopy is steadily increasing around the world as multiple studies have demonstrated improved intubation success rates with use of these devices compared with traditional direct laryngoscopes in a variety of clinical settings.11,12 (See “Seeing the Difference: Deploying the video laryngoscope into a ground EMS system, by Mark E.A. Escott, MD, MPH, FACEP; Guy R. Gleisberg, MBA, BSEE, NREMT-B; Lee S. Gillum, MPH, BS, LP; et al., in the August 2014 issue of JEMS.)
However, one commonly encountered obstacle to the successful use of this technology is excessive fluid in the airway that may obscure the camera lens at the distal end of the laryngoscope blade. If the video laryngoscope has a hyperangulated geometry blade, such as the Glidescope Ranger or King Vision, the laryngoscope must be removed from the mouth and the camera wiped clean before another attempt at intubation can be made. If the video laryngoscope has a standard geometry blade, such as the Glidescope Direct Trainer or McGrath MAC, then the intubator may abort using the video capabilities and immediately attempt traditional direct laryngoscopy.13 All providers using a video laryngoscope should be aware of these subtle but critically different clinical applications.
Either way, the enemy of video laryngoscopes is always blood, vomit and secretions in the airway. As agencies train on and deploy these devices, it’s imperative providers recognize the critical importance of aggressive suctioning both prior to blade insertion and throughout the entire course of airway management. Future use of video laryngoscope blades with integrated suction near the distal camera may solve this problem.14—16
A FORGOTTEN SUCTION
While this article has focused primarily on airway suctioning, we should also mention the importance of gastric suction as a potential adjunct tool during airway management. Whether by nasogastric (NG) or orogastric (OG) tube placement, removing air and stomach contents from the critically ill patient can significantly decrease the risk of vomiting, thus preventing a more difficult intubation and possible aspiration.17 This is particularly applicable after a long period of positive pressure ventilation via BVM. As a result, some clinicians advocate for the placement of an OG or NG tube before intubation if the patient’s clinical status and local protocols allow.18-19 In addition, stomach decompression whether before or after intubation can decrease the pressure on the diaphragm and thus potentially facilitate more effective respiratory ventilation during long transports.20
CONCLUSION
Managing the unstable airway is a mission-critical skill for all EMS providers. Timely and effective suctioning is one of the core building blocks upon which this skill rests. Failure to remove secretions, blood, vomit and other foreign material from a patient’s airway can result in both immediate and long-term catastrophic consequences from failed intubations to aspiration pneumonia. However, with continued education on the art of suctioning, frequent training, routine equipment checks and calculated utilization, EMS providers are uniquely positioned to stabilize the airway and thus improve patient outcomes.
REFERENCES
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19. Salem MR, Khorasani A, Saatee S, et al. Gastric tubes and airway management in patients at risk of aspiration: History, current concepts, and proposal of an algorithm. Anesth Analg. 2014;118(3):569—579.
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