By Charlie Eisele, BS, NREMT-P, & Jimmie Meurrens, BS, NREMT-P
Is the juice worth the squeeze?
We ask ourselves that after every prehospital journal or magazine article we read. When we dive into the literature, we want to come out more knowledgeable and capable of using the information on our next call.
If you’re like us, you like to know that you didn’t waste 20 minutes or more reading something that’s going to take another class or special permission to use. So we promise that after consuming the information in this article, you’ll be able to immediately apply it and improve the level of care you deliver in the field.
Nationally recognized EMS textbook author and JEMS contributing author Bryan E. Bledsoe, DO, FACEP, recently wrote, “[Endotracheal intubation] is problematic and the procedure should probably be stopped.” He added, “Everybody better get used to LMAs, Combi-Tubes and similar rescue airways because routine prehospital ETI is probably a thing of the past.”
For those who haven’t heard about recent studies on the success rates and efficacy of prehospital intubation, Bledsoe’s comments might seem like a step backward in prehospital medicine. But his concern is valid. Several prominent studies have strengthened a growing concern about this intervention, and as EMS professionals, we can’t ignore what the science is showing us.
Specifically, we should note the findings from a St. Luke’s-Roosevelt Hospital, Columbia University 2004 study. The researchers found that endotracheal (ET) tubes placed by paramedics in the prehospital setting were incorrectly placed “at a concerning rateÚ and appeared to be associated with poor outcomes.” What rate constitutes “concerning?” Nearly one-third. In the 10-month study, the researchers found that approximately 29.5% of intubated patients arrived at the emergency department (ED) with improperly placed ET tubes.
Those results are similar to those of research conducted by the University of Pittsburgh School of Medicine in 2006. In a detailed study of roughly 2,000 patients, the researchers found a 22.7% error rate associated with paramedic prehospital intubation.
These two studies, and a number of others, suggest that prehospital intubation may be adversely affecting patients due to misplaced or dislodged tubes, leading to subsequent inadequate oxygenation and ventilation management. Such findings and expert commentary should serve as a wake-up call to all prehospital providers. We shouldn’t be concerned that a procedure may be taken away, but rather that we’re performing a procedure with substandard skill. It’s time we all get on board to reduce the incidence of prehospital intubation errors and ineffectiveness.
Thus, the art of post-intubation management is born. Its principles will guide you in properly confirming tube placement and securing the tube to prevent inadvertent extubation and to ensure maximum tube efficacy. Additionally, implementing specific oxygenation and ventilation strategies will provide optimal therapeutic benefit to both hemodynamically compromised and head-injured patients. Individually simple; the applied sum of these principles is profound.
Confirm the Tube
No single technique is 100% positive proof of proper tube placement every minute we’re with the patient. But a mere hunch, suspicion or feeling is not adequate. Confirmation relies on assessing multiple parameters and weighing the validity of each. Don’t let one parameter sway you into believing a tube is good if all the other elements say it’s bad. Let’s look at a few commonly used parameters.
Direct visualization: This method provides an instantaneous value. It’s valid as long as you’re looking at it. Ever have the glottis squarely in your sights, slide the tube and look away at the last second? We have. You can watch the tube all the way in, withdraw the laryngoscope blade gently, and still drag the tube out of the glottis while removing the blade.
Tube depth: Measured at the incisors, a general rule of thumb is that the depth should be three times the tube diameter. For adult males, look for a depth of 21Ï23 cm; in adult females, aim for 20Ï22 cm. A change in tube depth is a good method to identify tube movement, but it doesn’t tell you if the tip of the tube has curled up and moved. You can secure the tube so well that you couldn’t pull it out with a come-a-long and a pair of vice grips, but just flex the patient’s head and out pops the tip of the tube.
Epigastric sounds (or the lack thereof): Listen for these sounds before lung auscultation. If you hear sounds, the tube is probably in the esophagus. If no sounds are noted, it means no air is entering the stomach. Sound quality is dependent on obesity, thoracic trauma, ambient noise, pregnancy and patient movement, as well as the provider’s skill, experience and equipment.
Breath sounds: Listen before you intubate. Are they the same or better after you dropped the tube? During the 2007 EMS Today Conference & Exposition, Bob Page, CCEMT-P, spoke in detail about capnography. He made a great point: We should listen to breath sounds to help judge bronchial placementƒnot for tube confirmation.
Listen bilaterally along the axillary line to ensure you have bilateral breath sounds. Again, sound quality can be affected by obesity, thoracic trauma, ambient noise, pregnancy, patient movement, provider skill and equipment. If the tip of the tube is above the glottis, you can still get breath sounds. You’ll also hear breath sounds if you’re doing proficient BVM ventilation.
Chest expansion: Visualize and palpate the chest. You should identify symmetrical rise and fall of the chest with each ventilation. Remember that Esophageal ET tube placement can cause chest movement. Also, remember that the quality of chest wall movement is affected by obesity, pregnancy, lung disease, chest trauma and patient movement.
Bag compliance: This tells us the ease with which the lungs expand when we ventilate. Simply put, if it’s easy to bag the patient, compliance is sufficient; if it’s difficult to bag the patient, you’ve achieved poor compliance. You should check compliance before and after placing the tube to identify any changes. We want consistently good compliance. A change in compliance may reveal an airway problem.
Increasingly better compliance may mean we’re doing a good job of opening the lower airway and ventilating the patient. But it can also mean the ventilation circuit has a leak somewhere. Is the tube disconnected from the BVM? Is there a cuff leak?
Increasingly poor compliance may indicate a dislodged ET tube, gastric distention, ET tube obstruction (due to blood, secretions, a tube kink or a patient biting the tube), an expanding pneumothorax, mainstem intubation, or that the patient is breathing against your ventilation attempts.
Esophageal detector devices (EDDs):These devices come in two styles: syringe aspiration technique and self-inflating bulb. Put the unit on the ET tube and withdraw the syringe or release the bulb. If the syringe draws easily or the bulb fills with air, the tip of the tube is presumed to be in the rigid trachea. If the syringe doesn’t easily withdraw or the bulb doesn’t inflate, the tip of the tube is presumed to be in the soft, flexible tissue of the esophagus or somewhere other than the trachea.
EDDs are inexpensive, and most studies have found them to be reliableƒwith 95Ï100% accuracy. However, false positives (i.e., the ET tube is in the esophagus but the bulb inflates) have occurred in patients with esophageal intubations who have been vigorously ventilated prior to using the EDD and in patients who have had BVM ventilation without cricoid pressure. False negatives (i.e., the ET tube is in the trachea but the bulb doesn’t inflate) have also occurred and are associated with a tube depth greater than 22 cm, obese or pregnant patients, a kinked ET tube, status asthmaticus, pulmonary edema, tracheal injury and bronchospasms. Despite the false positives and negatives, the EDD remains a good tool.
End-tidalCO: Measuring EtCO via capnography has truly become the gold standard in tube verification and the expected standard of care. San Diego Fire-Rescue Assistant Chief Criss Brainard noted during his session at this year’s EMS Today that it provides “objective, quantified and documented proof.” This objectivity is established via a numerical value with breath-to-breath waveforms that can be used to verify ET tube placement and guide ventilation rates. It also provides documentation to back up your assessment and action.
False readings occur on rare occasions. False positives (i.e., when the ET tube is in the trachea, but no EtCO is detected) are associated with operator error, sensor contamination, unit calibration, cardiac arrest with poor CPR, pulmonary embolism, severe asthma and pulmonary edema. False negatives (i.e., the ET tube is not in trachea but EtCO is present) have been linked to operator error, sensor contamination, unit calibration, hypo-pharyngeal intubation (supraglottic tube placement) and severe gastric distension.
Patient status: How is your patient doing? How are the vital signs? There’s always a case when the patient gets worse regardless of your actions. However, in most cases, the patient should get better, or at least not deteriorate.
Endotracheal tube verification is a collection and assessment of multiple factors. Don’t let one sign convince you to leave the tube in place when everything else is saying “no.” Not sure of the placement? Pull the tube and bag ’em at the very least.
Secure the Tube
How much time did you spend last year training to place a tube? And how much time did you spend training tosecure the tube? We do a disservice to our patients and our profession when we think our job is done once we drop the tube. Typically, we move an intubated patient four to five times before we turn over care to hospital staff. Moving the patient is one of the prime opportunities to lose a tube. Let’s see what we can do to lessen that chance.
You’ve successfully inserted the ET tube through the glottic opening. Now start securing the tube. Before withdrawing the stylette, manually pin the tube against the upper incisors and inflate the cuff. This technique will lessen the chance of moving the distal tip of the tube while withdrawing the stylette.
An anchoring system has three components: the anchor (the patient’s head), the tube, and the anchor connection between the two. Anchor connections for securing endotracheal tubes in the field can be broadly classified into four groups: 1) adhesive tape, 2) cloth tape, 3) commercial devices and 4) homemade stuff.
Adhesive tape:Applied to the face and tube, adhesive tape is primarily used for pediatric patients. The act of taping is personal and more elaborate than origami, so we won’t try to convince you that one method is best. But we will share some tricks that have worked for us.
Tape doesn’t secure well in the presence of facial hair, blood, vomit, burns or any loose material on the face. So dry the skin and apply tincture of benzoine to help with adhesion. Of course, a towel and benzoine won’t remove facial hair and should not be used on burns.
Apply the tape to the maxilla. Wrapping the tape completely around the head (occiput) also works well. Anchoring the tube to a movable structure (such as the mandible) increases the chance of displacing the tube.
Determine the tube depth at the incisors and write it down before you start wrapping tape on the tube. It would also be prudent to leave the number at the incisors exposed so you can see it to check for movement. (Tip:Create a tab at the end of the tape by folding over the end of the tape on itself; this will make it easier to unwrap the tape from the tube.)
Cloth tape:Tie cloth tape (aka, twill or umbilical tape) to the tube, wrap it around the patient’s head and then tie the ends of the tape together. We were amazed to find more than 20 studies on which kind of knot to use; it was a tie between the girth hitch and clove hitch. If you’re not sure how to tie these two knots, check with a Boy Scout nearby.
Do not overtighten the knot on the tube; it can occlude it. This is especially true with the Endotrol Tracheal Tube and pediatric tubes. Use a bow (yes, a bow) to tie the ends of the tube together so it will be easy to untie the tape when necessary.
Commerical devices:In researching this article, we found more commercial devices than we thought could possibly exist. With that said, we won’t even begin to discuss individual devices. Some are excellent; others, not so great. The key is to know how to use what you have before you need it so you’re not pulling out the instructions in the middle of a call. You can use a variety of means to actually secure the tube to a commercial device. We find that clamps work best but, like cloth tape, you can overtighten the clamp and occlude the tube.
We like the fact that most commercial devices have some kind of bite block attached, because this is commonly overlooked. Unlike on an oral airway, the bite blocks on commercial devices are usually so short they don’t tickle the patient’s gag reflex. Speaking of bite blocks,use them. If you forget, your patient will remind you. An oropharyngeal airway (OPA) is good, but be gentle. Vigorous movement in the mouth can dislodge the tube.
One last note about commercial devices: Dutton’s Corollary states, “The chance of something actually working in an emergency is inversely proportional to the number of moving parts it has.” Simple is better.
Homemade stuff: Clinician-fashioned devices and techniques reveal highly detailed and personal contrivances, which can be ritualistic. ET tube security seems to bring out the inventor, the handyman, and the obsessive-compulsive in all of us. Some of the homemade or modified devices we’ve seen include wire, sutures, Velcro_, plastic tubing, molded rubber, tongue depressors, umbilical clamps, safety pins, rubber bands and cable ties.
Our favorite is IV tubing. We like the tubing from a 60-drop set. It’s easy to carry and virtually immune to blood, sweat, facial hair, vomit and rain. It works well when trauma results in poor facial structure.
Throw it on the tube with a girth hitch, slide the hitch to the lip, wrap the tubing around the patient’s head, and tie it off in a bow. However, it can be overtightened, so we don’t recommend it for Endotrol or pediatric tubes.
Secure the Patient
Forall intubated patientsƒtrauma or medicalƒapply a cervical collar and head blocks or use a specially designed head/airway immobilizer (see p. 53). This limits excessive head and neck movement. You will get questioning stares at the receiving hospital when you present an intubated medical patient with a collar and head blocks. But, if it keeps your tube in the right hole, who cares if they stare?
Also, secure the patient’s torso and hands. It doesn’t make much sense to strap the patient’s head down and let their body roll around. Self-extubation is common, so secure the patient’s hands below their waist. Sedatives and paralytics are poor replacements for properly securing a patient.
Provider-induced extubation is another top way to dislodge an ETT, especially when moving the patient. The best prevention is to slow down. Have one person manage the airway throughout the move. Verbalize this process so everyone is aware which person is in charge of each part of the move. Disconnect the BVM before moving the patient. If you need to ventilate, stop the move. Plan the move and ensure everyone knows the plan. Move slowly, and pay attention to what you’re doing.
Oxygenate & Ventilate
We briefly touched on capnography for tube confirmation. It’s also an extremely valuable tool for continued definitive tube confirmation as well as for guiding ventilation. Hyperventilation was for a long time the treatment of choice for all head-injured patients. Over time, however, it has proven to be an ineffective treatment modality for some head injuries.
When you hyperventilate someone, CO levels fall and cerebral vasoconstriction ensues. This vasoconstriction is great for head-injured patients exhibiting signs and symptoms of herniation syndrome, e.g., blown or unequal pupils, posturing or Cushing’s triad (i.e., decreased pulse and respiratory rate, increased systolic BP, and widened pulse pressure due to increased intracranial pressure). But for all other head-injured patients, the hyperventilation and subsequent vasoconstriction will unnecessarily reduce cerebral blood flow.
Also, remember that maintaining oxygenation should be your first priority. Specifically, you shouldn’t sacrifice SpO for EtCO levels. With that said, overzealous and uncontrolled hyperventilation shouldn’t occur. You should have set end-target EtCO values for head-injured patients with and without the signs and symptoms of herniation. Check with your medical director for numerical guidance.
Just as hyperventilation is out for all head injuries, so is the concept of hyperventilating intubated patients who are hemodynamically compromised. Those patients consist of post-arrest, multisystem trauma and those who are otherwise sick/injured and hemodynamically unstable.
For example, consider a patient who has been shot twice in the abdomen. His abdomen is becoming rigid and distended, and he’s hypotensive, tachycardic, cool, pale and diaphoretic. Your physical exam findings and baseline set of vitals indicate intra-abdominal bleeding. Because he has a GCS of 3 and an absent gag reflex, you correctly decide to intubate him to secure his airway. What now?
In addition to rapid transport and responsible fluid therapy, your treatment considerations should include a ventilation strategy that assists the patient’s inherent respirations at a rate and depth great enough only to maintain acceptable oxygenation.
Every consideration should be given to not inducing positive pressure ventilations. The positive pressure induced into the patient’s thoracic cavity would increase thoracic pressure and reduce venous return, worsening his already compromised hemodynamic status.
However, assisting his ventilations enough to maintain only oxygenation allows for his inherent respirations to continually apply negative pressure in his thoracic cavity. This negative pressure assists venous return and helps maintain the circulation the patient so desperately needs. The same physiological principle applies to the other subsets of patients mentioned as well.
Confirm the tube; secure the tube. Ventilate the patient; oxygenate the patient. Simple, but profound. Our job is done when the receiving physician accepts the patient with a thumbs-up to the tube. We hope to read journal articles in the near future that sing the praises of superb prehospital airway care. It starts with you. Do what’s best for your patientƒand strive to improveƒso the juice becomes worth the squeeze.
Charlie Eisele, BS, NREMT-P, is a flight paramedic and state trooper. He has been an EMS and technical rescue instructor for more than 26 years and serves as an airwayinstructorfor the R Adams Cowley Shock Trauma.
Jimmie Meurrens, BS, NREMT-P, has been a paramedic for 10 years and is a flight paramedic for the Maryland State Police, Aviation Command.
Learn more from Charlie Eisele at the EMS Today Conference & Expo, March 2-6 in Baltimore.
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2. Wirtz DD, Ortiz CA, Newman DH. “Rate and outcomes of unrecognized esophageal placement of endotracheal tubes by paramedics in an urban emergency department”. Academic Emergency Medicine 2004;11:591-592.
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7. Paris BL, Flaxman A, St_rmann K. “The insecure airway: A comparison of knots and commercial devices for securing endotracheal tubes”. Academic Emergency Medicine 2003;10:485-486.
8. Personal conversation with Richard Dutton, MD. R.AdamsCowleyShockTraumaCenter, 2006.