No CPAP device will accomplish its goal if the patient can’t tolerate its application. To facilitate successful use, consider the following tips.
Don’t start with the Head Straps
Patients in respiratory distress often feel claustrophobic when a tight-fitting mask is applied, particularly with straps. One option: Ask the patient to hold the mask to their face. Keep your hand on the mask and provide verbal encouragement. This allows you to assess compliance with the procedure and evaluate their mental status, level of consciousness and ability to breathe spontaneously.
Another advantage of holding the mask: It requires you to stay close to the patient and coach them to breathe in through their nose and out through their mouth. This prevents incoming air/oxygen from hitting the back of the throat, minimizing the gag reflex, and it reduces the likelihood of gastric distension, which can result in vomiting. In addition, one of the side effects of CPAP with a higher level of PEEP is a decrease in blood pressure. Close contact and monitoring will lessen the possibility of side effects going undetected.
If the patient is tolerating the therapy well and the clinical condition is clearly improving, apply straps per local protocol.
Tip: If the patient doesn’t tolerate CPAP well, allow them to remove the mask and breathe normally, then have them reapply it when they feel more comfortable. Intermittent CPAP is better than no CPAP at all.
Use Coaching to Improve Compliance
“CPAP virgins” are often fearful and anxious, particularly if they’re also hypoxic. It’s therefore vital that, before starting CPAP, you explain to the patient what to expect.
Don’t approach the severely short-of-breath patient with mask in hand, telling them you’re going to apply a tight-fitting mask to their face to help them breathe. Instead, refer to the device like you do any oxygen-delivery system, saying, “I’m going to give you some oxygen to breathe. Once it starts, it may be difficult for you to talk to me, so I want you to listen to me and follow my instructions. This will feel odd at first and it will be loud. But if you breathe through your nose and out through your mouth, you’ll feel better.” Try calling it a special mask that will help them breathe more easily.
Tip: Don’t tell the patient the procedure may make them gag or vomit; this can result in a self-fulfilling prophecy.
ALS providers should consider administering a small dose of an anxiolytic drug, such as lorazepam, in conjunction with CPAP. A dose of 0.5 to 1 mg IV lorazepam (or 2 mg IV pyelogram midazolam) is usually sufficient to reduce the anxiety associated with CPAP administration or respiratory distress, without decreasing the patient’s ventilator drive. Repeat doses may be administered as needed as long as the patient continues to follow directions.
Diazepam may be used, but with caution, because it’s more likely to cause respiratory depression. Start with 1 mg IV; titrate as needed.
Apply Nitrates Via an IV
The primary medication for the treatment of heart failure is nitrates, usually delivered via sublingual tabs or spray. Tablets require temporary lifting of the CPAP mask to administer. Some patients in respiratory distress have a dry mouth, and the sublingual tabs may not be efficiently absorbed under the tongue.
If tablets are the only choice, place a drop of water or saline on the tablet when placed sublingually, or have the patient suck on the tablet. Use of the spray may be accomplished with minimal breaking of the mask/face seal by sliding the dispenser straw under the mask and spraying the nitrate directly into the open mouth. Don’t forget to follow this with transdermal nitrates in the field.
The most effective means of nitrate administration for heart failure, however, is IV, because it allows more judicious titration. Even in services with relatively short transport times, the use of IV nitrates has proved very effective, particularly if started early.
Use a Nasal Cannula for Capnography
Capnography, the standard of care for the intubated patient, should also be used with CPAP. Many CPAP devices have ports or connectors to the circuit that are used to monitor EtCO2. However, the use of ports or connecting sites in the circuit can result in significant blunting of the graph and washout of the reading.
A recent study performed by HealthEast Medical Transportation in St. Paul, Minn., demonstrated that the only reliable method of using capnography with CPAP is the application of a nasal cannula that has both oral and nasal sampling ports.
A Final Bit of Advice
When using CPAP in the field, there’s no need to reinvent the wheel. Consult with other agencies and resources for other best practices and tips. By keeping your patient’s comfort in mind, you’ll ensure better results and build confidence to regularly tap the benefits of this powerful therapy.
This article originally appeared in the January 2011 JEMS supplement “CPAP: The push for rapid relief” as “Proceed with Caution: How to apply CPAP with patient comfort in mind”