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The following are the most common errors in the evaluation and management of people with respiratory muscle dysfunction as fully explained in Bach JR, Management of Patients with Neuromuscular Disease, Elsevier 2004:


1. Misinterpretation of symptoms:

People who can walk but who have limited breathing muscle reserve complain of shortness of breath before developing acute respiratory failure. People in wheelchairs may not. Instead, these people tend to complain of anxiety and inability to sleep in the moments preceding acute respiratory failure.


2. Ordering pulmonary function testing (PFTs) rather than evaluation with:


-Peak flow meter



at every outpatient visit of every infant and adult with an Applicable Condition.


3. Failure to evaluate vital capacity (VC) with spirometry with the patient in multiple positions:



-Circumstances such as with a chest brace on and off


4. Failure to evaluate maximum insufflation capacity (MIC) and gossopharyngeal maximum single breath capacity (GPmaxSBC) with spirometry at every outpatient visit.


5. Failure to evaluate cough peak flows (CPF).


6. Ordering arterial blood gas analyses rather than noninvasive monitoring of oxygen saturation (O2 sat) and CO2 levels. (Up to 30% of arterial blood gas analyses cause the patient to hyperventilate due to pain from the arterial stick. This lowers actual baseline CO2 levels.)


7. Unnecessary resort to bronchoscopy, endotracheal intubation, and tracheotomy which can be avoided by using noninvasive ventilatory support (NVS) and mechanical insufflation-exsufflation (MIE) appropriately.


8. Failure to try multiple noninvasive interfaces for fit, comfort, and efficacy to find the best fit.





1. Failure to deflate tracheostomy tube cuffs (or opt for cuffless tubes) thereby preventing the patient from speaking and increasing risk of complications from the tube cuff (e.g. tracheal damage).


2. Use of tracheal and airway suctioning, oxygen supplementation, and bronchodilators rather than NVS with MIE at optimal settings of 50 to 60 cm H2O insufflation and exsufflation.


3. Use of phrenic and diaphragm pacemakers and body ventilators that cause obstructive apneas and do not permit air stacking.


4. Use of CPAP or suboptimal low-span bi-level PAP instead of NVS.


5. Use of pressure-preset rather than volume-preset ventilation for people who can air stack.


6. Failure to extend NVS use into daytime hours and switch patients from nasal to mouthpiece interfaces.


7. Failure to use non-vented interfaces (nasal or oronasal interfaces without ports/holes or with ports/holes covered) with active ventilator circuits which have exhalation valves that permit air stacking.


8. Failure to train in glossopharyngeal breathing (GPB) for ventilator-free breathing ability.


9. Failure to extubate unweanable patients to continuous NVS and MIE, that is, failure to extubate to wean rather than wean to extubate.


10. Confusion with noninvasive ventilation (see NIV) and use of polysomnograms (see polysomnography).


11. Potentially harmful treatments:

People with healthy lungs but weak muscles are often treated with oxygen therapy, bronchodilators, and nebulizer use (asthma treatments). Oxygen must never be used as a substitute for NVS/MIE since it renders the oximeter useless as a gauge of effective lung ventilation and depresses breathing while exacerbating CO2 levels in the blood.


12. Resort to tracheotomy:

Tracheostomy tubes placed through the neck and into the windpipe are not necessary for ventilatory (“respiratory”) support for people satisfying certain criteria, in particular, alert infants and cooperative older people with healthy lungs and only weak respiratory muscles. Even people with no strength to breathe who use continuous noninvasive ventilatory support (CNVS) do not need tracheostomy tubes.


13. Use of chest oscillation devices:

Chest oscillation devices do not substitute for cough and do not prevent pneumonia and respiratory failure for people with weak muscles. Instead, mechanical insufflation-exsufflation devices (see MIE) must be used.

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