In the past decade, very few changes have occurred in the prehospital treatment of patients in respiratory distress.
The standard approach for EMS, including Mesa (Ariz.) Fire and Medical Department (MFMD), was to place the patient on 100% oxygen via a non-rebreather mask, or if needed, ventilation via a bag-valve mask for respiratory distress and failure.
In conjunction with airway management, the patient would also receive medication depending on the field diagnosis. If the patient was in congestive heart failure (CHF), nitroglycerine and Lasix (furosemide) would be administered. If they were suffering an exacerbation of their reactive airway disease, they would receive a small-volume nebulizer with beta-2 agonists, magnesium sulfate and solumedrol.
Many times, the patients waited too long to call EMS or their disease had developed beyond the point where current treatment modalities could stop the progression of the illness, requiring invasive airway management (i.e., intubation).
Depending on agency policy and procedures, providers would either intubate the patient utilizing rapid sequence intubation/medication assisted intubation (RSI/MAI), or they would wait until the patient was obtunded enough to place a laryngoscope.
It’s well-documented that morbidity and mortality is increased when a patient is intubated, and if you can prevent this invasive procedure with its associated complications, patient outcomes improve and healthcare costs decrease significantly.1,2
Evidence-based medicine supports the implementation of noninvasive positive pressure ventilation (NPPV) as a first-line treatment for acute respiratory failure in the prehospital setting prior to intubation attempts and invasive ventilation.3,4 The inclusion criteria should be based upon patient presentation and provider impression rather than a specific diagnosis.
Patients present with respiratory distress from a multitude of etiologies.
Unless NPPV is contraindicated–even in the best-controlled situations–advanced airway management such as intubation isn’t without risk. The chance of a complication resulting from a prehospital RSI/MAI is extremely high.
It has also been documented that length of stay in the hospital is decreased if intubation can be prevented utilizing NPPV.2 Larger studies are needed to evaluate the benefits of NPPV application in the prehospital setting by analyzing the following:
- Outcomes of patients placed on NPPV in the prehospital setting;
- Decrease in healthcare costs from the application of prehospital NPPV;
- If use of NPPV decreased the number of elective intubations in the prehospital setting;
- If NPPV was continued in the ED;
- Improved prehospital NPPV protocols based on evidence-based medicine;
- If it’s financially beneficial for the hospital to help support prehospital NPPV; and
- Application of prehospital NPPV in pediatric patients.
- Differences in NPPV, CPAP & Bi-Level
Both continuous positive airway pressure (CPAP) and NPPV apply positive pressure to the airway via an interface, but there are distinct differences. CPAP supports the airway by increasing lung volumes, functional residual capacity and intrathoracic pressure, but it doesn’t decrease the work on the muscles of respiration. Tidal volume, the volume of gas inhaled, is solely dependent on patient effort and the work of breathing.
NPPV utilizes two levels of pressure. One is the pressure during exhalation, which is referred to as expiratory positive airway pressure (EPAP). The other is referred to as inspiratory positive airway pressure (IPAP).
This bi-level pressure (BiPAP) has all the benefits of CPAP, but also assists or controls the pressure applied during inspiration, which will decrease the work of respiration by assisting or supporting the patient when they attempt to take a breath. In some circumstances, the device can also be time-cycled to deliver a controlled breath if the patient becomes apneic or has episodes of bradypnea. The interface of choice for emergent NPPV is an oronasal mask to prevent leaks and increase patient comfort.
MFMD recognized the need to investigate other options in our treatment protocols for providing assistance to our patients in respiratory distress. The goal was to decrease the number of patients who would require prehospital intubation. However, if they did require intubation, they would be ventilated with a safe and appropriate mechanical ventilator.
Prehospital CPAP has been effective and has been proven beneficial for a select group of patients in hypoxic respiratory distress/failure, but it only works on a select group of patients. Instead of implementing CPAP alone, MFMD decided to wait for the technology and find a device that was capable of providing CPAP, BiPAP and invasive ventilation. We spent countless hours evaluating and bench-testing ventilators with specific capabilities in mind.
Generating Evidence-Based Protocols & Training Providers
One of the most challenging obstacles MFMD faced during the implementation of NPPV in the prehospital setting was the absence of any provider protocols. We had to start from scratch, utilizing current best practices from hospital-based medicine since no research has been published on NPPV use and application in the prehospital setting.
We also had to teach new concepts that hadn’t been taught to paramedics in the past. Figure 1 supports the offline algorithm developed by MFMD to refer to for best prehospital ventilation practices. Protocol development was done using the American Association of Respiratory Care’s journal, Repiratory Care, as a primary resource.
Figure 1: Mesa Fire and Medical Department NPPV/BiPAP flowchart
Once the protocols were developed, we next faced the challenge of training providers. With most other programs taught, a curriculum or lesson plan was already available. In this case, however, we had no road map and had to start organically.
When consulting with respiratory therapy professionals, we were told: “You can’t train paramedics to provide NPPV. It’s not going to work.” This struck a nerve and strengthened our determination. The best advice we received from colleagues was to “keep it simple.” This became our mantra.
Yes, it did take time to develop and teach the program. We utilized passionate, skillful trainers drawn from the ranks of the providers. The results far surpassed expectations, reminding us that our providers are bright, intelligent medical professionals who want the best for their patients.
MFMD utilizes a fire-based response model. Our typical response includes two paramedics and two EMTs. When developing our crew-based training plan for prehospital ventilation, we included the EMTs in all the training.
This plan proved to be of great benefit. The EMTs embraced the training and were able to grasp the new concepts as fast as the ALS providers. We also noticed the EMTs were setting up the ventilator from the direction of the paramedic.
This team approach improved the time it takes to rapidly deploy the ventilator and allowed the paramedic to provide other lifesaving treatments prior to ventilator application. This was noticed when utilizing scenario-based training.
Positive (Pressure) Results
The go-live date for NPPV was April 1, and the first call came at 10:52 a.m. In the first month, we had 20 applications of NPPV, including three in one day. Not only were providers using it correctly, but in 13 out of 20 patients (65%), providers stated they would have intubated their patients if NPPV hadn’t been available. Those 20 patients had relief to the point they didn’t need intubation in the field or ED.
Providers were spreading positive results faster than the speed of light as one good outcome led to another. The NPPV modality became contagious, as were the tales of a rapid, dramatic improvement in dyspnea after only being on NPPV for a short period of time. Prehospital personnel are true patient advocates, and when they see a treatment or drug that makes a patient feel better or one that gives them the ability to do their job better, they will step up to the challenge.
The application of NPPV, when used for some of the different provider impression/diagnosis that MFMD has utilized it for, has been significant. After only a short period of time, we’ve seen NPPV applied on patients we wouldn’t have predicted. We’ve seen it used on several with end-stage diseases who would have been intubated and spent their last days or hours on life support with an endotracheal tube in their airway. Instead, they were able to make end-of-life decisions and die comfortably with dignity.
Data is collected from all NPPV patient outcomes after ED admission, including whether NPPV was continued, and if so, for how long; whether the patient was admitted or discharged; admission destination (e.g., ICU, telemetry); arterial blood gas results; chest X-ray results; whether or not the patient was intubated during their stay; discharge date and diagnosis.
In the first month, only two patients were intubated a few days after being admitted to the hospital. The rest either came off NPPV in the ED or shortly after their admission to the hospital. Their hospital stays averaged 3—6 days. Not only are the providers saving lives, which is their biggest reward, but they’re saving the healthcare system valuable resources and money by preventing potential intubations, ventilator-acquired pneumonias, long intensive hospital stays and possible long-term care costs for those who fail to wean from a ventilator.
When you can’t breathe, every second is an eternity. Our providers can quickly recognize patients who benefit from NPPV, using it in conjunction with the medications available to them for respiratory problems.
MFMD is four months along in our use of NPPV in the prehospital setting, and the results are very positive. Patients are getting the treatment they need when they need it and where they need it. NPPV is another tool that should help decrease intubation in a select group of patients in respiratory distress or impending respiratory failure, with intubation becoming a secondary, but sometimes necessary intervention.
1. Kraynek B, Best, J. (December 2011.) What are the clinical indications for noninvasive positive pressure ventilation? The Hospitalist. Retrieved Sept. 26, 2014 from www.the-hospitalist.org/details/article/1409003/What_Are_the_Clinical_Indications_for_Noninvasive_Positive_Pressure_Ventilation.html.
2. Grap MJ, Munro CL, Unoki T, et al. Ventilator-associated pneumonia: The potential critical role of emergency medicine in prevention. J Emerg Med. 2012;42(3):353—362.
3. Hess DR. Noninvasive ventilation for acute respiratory failure. Respir Care. 2013;58(6):950—972.
4. McNeill GBS, Glossop AJ. Clinical applications of non-invasive ventilation in critical care. Continuing Education in Anaesthesia, Critical Care & Pain. 2012;12(1);33-37.
- Daily JC, Wang HE. Noninvasive positive pressure ventilation: Resource document for the National Association of EMS Physicians position statement. Prehosp Emerg Care. 2011;15(3):432—438.
- Gray A, Goodacre S, Newby DE, et al. Noninvasive ventilation in acute cardiogenic pulmonary edema. N Engl J Med. 2008;359(2):142—151.
- Tomii K: Current strategies and equipment for noninvasive ventilation in emergency medicine. In AM Esquinas (Ed.), Noninvasive mechanical ventilation. Springer: New York, pp. 217—221, 2010.
Scenario for Respiratory Distress Simulation Training
Team is presented with a 60-year-old female with a history of shortness of breath and a productive cough for two days. Upon arrival patient is found in severe respiratory distress (Glasgow coma scale = 13, and speaking 3—4 word sentences). Patient has a history of chronic obstructive pulmonary disease and frequent pneumonias.
- Heart rate: 120 a fib
- Respiratory rate: 22
- Blood pressure: 160/78
- SpO2: 80%
- EtCO2: 88 mmhg
- Lung sounds: wheezing rales and rhonchi bilaterally
- Productive cough: dark brown/green mucus
- ECG: 120 (12-lead, non-diagnostic)
- Skin color: pale with blue nail beds
- Temperature: 102.8 degrees F axillary
Is this respiratory distress caused from low oxygen hypoxia, hypercarbia or combined? What’s your field diagnosis?
- 100% O2 and run to the hospital
- Intubate and ventilate
- NPPV (CPAP or BiPAP)
- Assist her with the bag-valve mask
NPPV Ventilator Setup
- Turn on
- New pt.
- IPAP =16; EPAP= 6; Rate =12
- Adjust time if needed–if RR > 24, decrease to 0.7
- Turn FiO2 to 50% and titrate down in increments of 10% down to 40%. Stop if it goes below 94% as most patients won’t require 100%.
- Adjust low min alarm down, adjust alarms PRN
- Pick appropriate interface and fit to patient
- Discuss the differences between CPAP and BiPaP
- Don’t forget SVN, solumedrol, magnesium sulfate and any other treatment as needed
- Lower FiO2 in 10% increments keeping SpO2 at 94%
- Any time a change is made, allow a little time for the patient to respond. Make one change at a time and always assess the effect it has on the patient.
- The patient should look like they’re breathing when they’re asleep.
- If patient is agitated, give Ativan/Versed in small increments; titrate to effect.
Patient Assessment Post-Ventilation
- Heart rate: 112
- Respiratory rate: 16
- Blood pressure: 120/70
- SpO2: 100%
- EtCO2: 78 mmhg
- Chest rise is poor
- Breath sounds: tight inspirations and expiratory wheezing scattered bilaterally with diminished bases
- Patient agitated, consider sedation
- The participant should increase the IPAP in 2 cmH2O increments until adequate chest rise and breath sounds are evaluated. Remember that EtCO2 can be misleading and will read lower than PaCO2 in patients with VQ mismatching
Perform a Complete Ventilator Check
Require the student to verbalize the vent check as they are performing a complete check:
- Exhaled tidal volume
- Rate set and actual
- I:E ratio–caution with obstructive lung disease always allow at least a 1:2 IE ratio
- Minute volume
Request a Full Report
- This should include initial vent settings and any changes made and how the patient tolerated your treatment.