Authors: Mei-Ean Yeow MD and Eytan Szmuilowicz MD
Background Non-Invasive Positive Pressure Ventilation (NPPV) can be used to palliate dyspnea in dying patients. Fast Fact #230 discusses medical decision making around using NPPV. This Fast Fact discusses practical aspects of using NPPV in dying patients. Little research has occurred on this topic; unless otherwise indicated the following discussion is empiric and based on clinician opinion and common practice.
Location The cost and experience needed to initiate NPPV limit its use to the hospital setting, with some exceptions (see below). Most NPPV use occurs in ICUs or transitional care (‘step-down’) units, and at some institutions continuous NPPV is not allowed outside of these settings. While the use of NPPV for palliation can occur at home or a hospice facility, it requires adequate nursing, respiratory therapy, and physician support to employ it safely. This can be a practical barrier to its use, and NPPV should not be offered unless one is sure it can be provided appropriately. Ensuring adequate respiratory therapist support is particularly crucial, as they have unique expertise at initiating and trouble-shooting the machines. Continuing NPPV for palliation in patients and families who are already comfortable managing home NPPV (e.g. for COPD or ALS) can be practical in the home or hospice facility setting, as long as it is consistent with care goals. Initiating NPPV in the home setting for dying patients is impractical and, given how uncertain its real benefits are (see Fast Fact #230), is not advised.
Masks: While full facemasks are commonly used in the in-patient setting, some patients find these claustrophobic. Nasal masks tend to be better-tolerated, but they do not work as well in patients who are mouth breathers. Patient preference and clinician familiarity should guide this decision.
Settings: Two parameters need to be set: the inspiratory positive airway pressure (IPAP) and end-expiratory positive pressure (EPAP). The breaths are usually triggered by the patient. On many devices it is possible to set a back-up rate if the patient does not trigger a breath spontaneously– this is inappropriate in dying patients receiving NPPV for symptom relief.
Strategies: There are two general approaches to initiating NPPV settings: a ‘high to low’ approach and a ‘low to high’ approach, referring to the initial IPAP settings. The EPAP is usually set at 3-5 cmH2O. In order to maximize the tolerability of NPPV for symptom relief in dying patients, a ‘low-high’ approach is recommended. Start with a lower IPAP (8-10 cmH2O), and gradually increase as tolerated to achieve alleviation of dyspnea, decreased respiratory rate, increased tidal volume, and patient-machine synchrony.
Monitoring Monitoring of pulse oximetry and arterial blood gases are not needed for patients using NPPV only for symptom control. Rather, the effect of NPPV should be assessed based on subjective improvement of dyspnea and decrease in respiratory rate. It is important to reassess patients frequently (looking specifically for respiratory rate, use of accessory muscles, and signs of anxiety), and to ask them if they are comfortable with the NPPV and deriving any benefit from it. Breaks from NPPV to eat, drink, and more freely communicate should be encouraged as much as patients desire.
Contraindications Contraindications are facial surgery/trauma/deformities that limit placement of the NPPV mask and patients with active nausea and vomiting. Decreased mental status is also considered a contraindication it increases the risk of aspiration from NPPV.
Discontinuing NPPV NPPV should be discontinued if it does not provide relief from dyspnea within an hour of the maximally tolerated setting, once a patient is no longer alert, or at any point when it is no longer meeting a patient’s goals. If the patient does not tolerate the mask, or feels claustrophobic, a small dose of a benzodiazepine can be administered to alleviate anxiety. If the patient is still uncomfortable, then NPPV should be stopped as it is then not adding to patient comfort. Opioids and benzodiazepines should be used to decrease dyspnea once NPPV is stopped. Remember that NPPV provides ventilatory support to patients and the work of breathing can dramatically increase without it. Be prepared to rapidly control any distressing symptoms, just as you would with discontinuing invasive mechanical ventilation (see Fast Facts #27, 33 and 34).
Nava S, et al. Multicenter, randomized study of the use of non-invasive ventilation (NIV) vs oxygen therapy (O2) in reducing respiratory distress in end-stage cancer patients. Am J Respir Crit Care Med. 2008; 177:A767.
Yeow M, Santanilla J. Non-invasive positive pressure ventilation in the emergency room. Emerg Med Clin N Am. 2008; 26:835-847.
Author Affiliations: Northwestern Memorial Hospital, Chicago, IL
Fast Facts and Concepts are edited by Drew A. Rosielle MD, Palliative Care Program, University of Minnesota Medical Center – Fairview Health Services, and are published by the End of Life/Palliative Education Resource Center at the Medical College of Wisconsin. For more information write to: firstname.lastname@example.org. More information, as well as the complete set of Fast Facts, are available at EPERC: http://www.mcw.edu/eperc. Readers can comment on this publication at the Fast Facts and Concepts Discussion Blog (http://epercfastfacts.blogspot.com).
Copyright/Referencing Information: Users are free to download and distribute Fast Facts for educational purposes only. Yeow M, Szmuilowicz E. Practical Aspects of Using NPPV at the End of Life. Fast Facts and Concepts. June 2010; 231. Available at: http://www.eperc.mcw.edu/EPERC/FastFactsIndex/ff_231.htm.
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