Respiratory Therapy

One of the most crucial avenues of support is respiratory therapy, including the use of mechanical ventilation to aid patients with weakened diaphragms and other respiratory muscles.

The use of mechanical ventilation can also prolong survival in late-stage cases, as patients with acute respiratory failure may be able to live for more than a decade longer with proper ventilatory support.¹

Ideally, patients should be referred to a pulmonologist prior to the onset of respiratory failure, although in many cases the signals may be subtle.

Patients with exercise intolerance may not complain of dyspnea given their inability to exert themselves, so other symptoms may present first. Morning headaches and somnolence are two early manifestations that may warrant further investigation.

Other signs include a decrease in vital capacity in a supine position and orthopnea. To determine the cause, a sleep evaluation or gas exchange assessment may be indicated.²

In many cases, a ventilatory support may only be needed initially at night to address nocturnal carbon dioxide retention and sleep disordered breathing (SDB). Because diurnal hypoventilation usually follows nocturnal hypoventilation, patients may increasingly need ventilation during the day as well.³

Noninvasive Ventilation

Patients with growing respiratory impairment typically begin by using noninvasive ventilation devices that deliver air through a mask that fits over the nose or mouth, or both.

Advantages of noninvasive ventilation devices:

Convenience
Portability
Low complications
Lower cost and morbidity, fewer infections, and reduced caregiver burden than invasive ventilation devices⁴

Currently, there are several different modes of ventilation available depending on patients' needs and ability to breathe spontaneously. Patients with the strength to inhale on their own may prefer a ventilator that follows their own breathing pattern, while others may need a ventilator programmed to automatically deliver breaths in preset cycles.

To initiate use, patients are generally referred to a respiratory therapist (RT), who may be available in a hospital or clinic setting. In some cases, the RT may visit patients' homes to provide training and assistance. The RT then typically follows up with patients for several weeks to ensure that the mask fits properly (with no leaks) and adjust the ventilator settings.

Noninvasive ventilation may not be feasible for:

Small children
Patients with claustrophobia
Patients with excessive secretions
Patients with swallowing or coughing difficulty
Patients with advanced cases that require more intensive respiratory support

Invasive Ventilation

In cases where noninvasive ventilation is not feasible, patients may not begin mechanical ventilation unless they are hospitalized for respiratory failure, which in some cases occurs when infection potentiates respiratory impairment. Intubation is generally employed in this scenario to deliver conditioned and oxygenated air to the lungs.

Once respiratory function stabilizes, "weaning" is usually attempted to determine if patients can breathe on their own entirely, or for a portion of the day. Some patients may not respond to weaning and may become permanently dependent on ventilation, however.

Although definitive guidelines have not been established, patients who appear that they will require mechanical ventilation 24-hours a day for a prolonged period of time and do not respond to weaning may become candidates for tracheostomy.⁵

Most modern devices have mechanisms that facilitate speech, such as a one-way valve that can be used along with a deflated cuff to allow patients to converse.

Tracheostomy has been associated with improved patient comfort and enhanced ability to participate in rehabilitation-oriented activities.[6] Tracheostomy openings should be cleaned daily to prevent infection.

For more information on common modes of ventilation, click here.

Other Forms of Respiratory Therapy

Another component of respiratory therapy is intermittent positive pressure breathing (IPPB), which can be administered by a RT in the hospital, clinic, or home setting in 10-15 minute sessions. IPPB helps to increase the patient's depth of breathing and can be used to deliver aerosol medications such as mucolytics to the lungs.

In some cases, an incentive spirometer may also be employed to increase inhaled lung volume and help eliminate mucus and saliva. Other "respiratory toilet" techniques that may help to clear pulmonary secretions include frequent suctioning and cough assist measures such as chest percussion.

Preventing Infections

Preventing infections is an important part of the total care of Pompe patients. Given that most patients have some degree of respiratory impairment, they are often highly susceptible to pulmonary exacerbations such as bronchitis and pneumonia.

Due to this vulnerability, vaccinations such as a flu shot, pneumoccal vaccine, or respiratory syncytial virus (RSV) vaccine may be considered. Infants in particular may encounter aspiration pneumonia as a major complication.⁷

As a result, any infection should be treated promptly before it progresses to a more serious stage. Should an infection worsen despite measures to curb it, mechanical ventilation can support patients through this critical period and help to prevent a decline in clinical status.

Dietary Therapy >

References

1. Hirschhorn, Rochelle and Arnold J. J. Reuser. Glycogen Storage Disease Type II: Acid Alpha-Glucosidase (Acid Maltase) Deficiency. In: Scriver C, Beaudet A, Sly W, Valle D, editors. The Metabolic and Molecular Bases of Inherited Disease. 8th Edition. New York: McGraw-Hill, 2001. 3389-3420.

2. Hill, Nicholas. Ventilator Management for Neuromuscular Disease. Semin Respir Crit Care Med 2002; 23(3): 293-305.

3. Hill, Nicholas. Ventilator Management for Neuromuscular Disease. Semin Respir Crit Care Med 2002; 23(3): 293-305.

4. Hill, Nicholas. Ventilator Management for Neuromuscular Disease. Semin Respir Crit Care Med 2002; 23(3): 293-305.

5. Harrison's Online. Chapter 266: Mechanical Ventilatory Support. The McGraw-Hill Companies. 2001-2002. Available at: www.harrisonsonline.com Accessed September 26, 2005.

6. Harrison's Online. Chapter 266: Mechanical Ventilatory Support. The McGraw-Hill Companies. 2001-2002. Available at: www.harrisonsonline.com Accessed September 26, 2005.

7. Ibrahim, Jennifer. Glycogen Storage Disease Type II. eMedicine Specialties. Available at: http://www.emedicine.com/ped/topic1866.htm Accessed September 26, 2005.

Disclaimer: The information contained is intended for educational purposes only. It is not a substitute for actual medical care. Persons requiring diagnosis or treatment or with questions specific to a single individual are urged to contact their local health care provider.