| Think about what kind of patients we are going to place on an in line
nebulizer. We probably had to intubate them or provide manual PPV because they were headed to respiratory arrest from some type of exacerbation of COPD, Asthma, or CHF.
If we are going to give a breathing treatment it is likely due to some obstructive airway or reactive airway disease. So likely, you have a patient that has air trapping (auto PEEP) with broncho-constriction and perhaps mucus plugging or hypersecretion. We must run 6-8 lpm to nebulize the bronchodilator medicine. In addition we provide PPV with 15 lpm O2 by BVM as we ventilate. The idea is the direct path to the lungs with the Albuterol, Ipatropium, or whatever you are nebulizing will hopefully quickly relieve the constriction, relaxing the musculature around the bronchioles, and hopefully, you should feel the compliance relax a bit. People with air trapping require prolonged expiration periods. If we don't allow for this, we can possibly make the patients auto peep (air trapping) worse, hyperexpanding the chest and inhibiting exhalation further. If you had to paralyze them to intubate, you're now relying on completely passive exhalation which won't fare well with obstructive airway diseases. Think about how hard the asthmatic or emphysema patient pushed to exhale when they were conscious.
Keep a close eye on cardiac output. Auto PEEP with PPV can inhibit venous return and affect cardiac output and BP. Pneumo is a complication from too much volume and pressure. It may be time to think about nebulizing some EPI or IV EPI if compliance is worse and the patient isn't improving. Always be weary, and monitor your patient very closely. A patient in our ambulance needing an inline nebulizer treatment with a reactive airway disease probably shouldnt be on the vent, due to increased expiratory phase of the patient with air trapping (our vents can't adjust for prolonged expiration like some of the more expensive ones although you can adjust to a degree by reducing the ventilatory rate and volume), added risk of baurotrauma, and volutrauma to the lungs. An exception to this would be near drowning or acute pulmonary edema, where grit or aspiration could be causing laryngospasm or fluid in the alveoli blocking gas exchange. PPV and PEEP help push fluid out, dilate bronchioles, and hold open alveoli.
With obstructive or reactive airway disease hand held BVM ventilation will allow a better tactile feel for patient progress. ETCO2 capnography (with the waveform) would be a very useful tool in this situation as well. The ETT ETCO2 monitor will fit between the ETT and the patient valve (from the vent circuit.) Be aware that the high humidity environment of the nebulized circuit could saturate the ETCo2 filter and effect sampling.
|UN-ASSEMBLED VIEW Without PEEP - Made entirely from parts of standard T-neb, "T" 22mm/30mm adaptor, and Vent 02 circuit parts that are carried on board our ambulances. Note when PEEP is NOT being used,
the exhaust collecter MUST BE REMOVED from the patient valve. |
|For CPAP use the same nebulizer bowel and the same "T" 22mm/30mm adaptor. Shown here assembled and unassembled. Thanks to Andy Muller for the push.