Respiratory care can improve quality of life
Second of a two-part series. Read the first part: "Breathe Easy: Options offered for respiratory care."
|"Breathe Easy" (Quest Vol. 5, no. 5) explains how neuromuscular diseases weaken the muscles that operate the lungs, including the diaphragm, leading to respiratory problems. It also describes forms of assistance with breathing and coughing that don't involve mechanical ventilation.|
The first time I used a ventilator, it was like breathing fresh air," says Larry Homolka. "It was like walking into an air-conditioned room. I promptly took a two-hour nap."
Homolka, an artist who lives in New York, has acid maltase deficiency. He uses a ventilator at night, and increasingly during the day, to compensate for his weakened respiratory muscles. Like thousands of other people with neuromuscular disease, Homolka discovered that mechanical ventilation offered him the means to improve, not simply extend, his life. In the words of Ed White of Fredericksburg, Texas, who has amyotrophic lateral sclerosis (ALS), "mechanical ventilation is the best 'drug' we have access to."
"Historically, mechanical ventilation was used for life support for people who couldn't breathe without a ventilator, people who would die immediately without one," says Edward Anthony Oppenheimer of the Pulmonary and Critical Care Medicine Division at Los Angeles Kaiser Permanente Medical Center. "Then, it was found that people with neuromuscular diseases did much better if they had a respiratory muscle rest, using mechanical ventilation for part of the 24 hours, usually at night."
As experience has shown, mechanical ventilation is increasingly seen not as a "desperate measure," but rather as a standard form of care for people with weakened respiratory muscles. Mechanical ventilation can not only extend life for people with neuromuscular disease, sometimes by decades, but can greatly improve its quality.
As Lori Hinderer of Tucson, Ariz., puts it, "I seem to have done more in this past year and a half than ever, and I owe it to my 'friend,' an LP6 ventilator by Aequitron."
Know your options
For almost every person who may eventually need mechanical ventilation, there is time to consider the options early on in the disease course. Planning ahead and understanding the choices available can make those choices easier, and help to avoid a respiratory crisis. Robert Warren, medical director of Pediatric Pulmonology Services at Arkansas Children's Hospital in Little Rock, says, "We do an assessment of need before implementation is actually required, eliminating the crisis event."
Warren's clinic provides new patients and their families with a booklet explaining the expected respiratory complications of muscular dystrophy, and outlining the choices available. This gives families the information they need to begin talking about ventilatory options years before they'll have to make choices.
Homolka wishes he'd gotten more information at the start: "I didn't get enough detail from my doctor at the beginning. She left too many mysteries. Once I saw what the ventilator was, I had no trouble accepting it." The lack of information can stem in part from scarcity of knowledge on the part of doctors. Oppenheimer notes that lack of home ventilator experience among medical professionals continues to be a serious obstacle to good patient care in this area.
Types of ventilator systems
A mechanical ventilation system includes both the machine that pumps the air — the ventilator — and the connecting system, or "interface." There are two major types of ventilators used for neuromuscular disease. The volume ventilator delivers a preset volume of air in each cycle, while the BiPAP (bilevel positive airway pressure) ventilator delivers air up to a preset pressure.
|Larry Homolka uses a mouthpiece to deliver ventilation during the day.|
While volume ventilators were the first type in use, bilevel pressure machines (such as the BiPAP S/T) are increasingly common. Oppenheimer notes that bilevel machines are both cheaper and lighter. However, they aren't yet approved for continuous use or for use with a tracheostomy, even though they're sometimes used this way.
While both types have safety alarms, volume ventilators have more safety features. Volume vents can also inflate the lungs more powerfully than a bilevel vent can, and can be used for air stacking (a technique that uses multiple breaths without exhaling to force as much air as possible into the lungs).
Warren prescribes volume ventilators in his clinic. "The volume ventilator can be used early on in the course of the disease — prior to the need for continuous assistance — as a lung inflation device intermittently throughout the day during an acute illness. As muscle weakness progresses, the same machine can be used up to 24 hours a day, when full mechanical assistance is desired," he said. This wide range of use makes it a versatile machine.
Bilevel vents are commonly used for nighttime assistance, to give ventilatory muscles a rest and to supplement the lower respiratory drive that comes with sleep. BiPAP and others like it were developed from the original CPAP (continuous positive airway pressure) machines.
As Oppenheimer explains, "The distinction between BiPAP and CPAP is a very important one. CPAP was designed as a treatment for obstructive sleep apnea, to keep the airway tissues apart so they wouldn't close down. But CPAP is by and large inappropriate for people with neuromuscular disease," in part because it requires more work for respiratory muscles to exhale against the continuous pressure.
Bilevel ventilators, on the other hand, still give extra inspiratory (air intake) pressure, high enough to inflate the lungs, but then the machine cycles to a lower pressure to allow easy exhalation. The slight amount of pressure in the second part of the cycle allows the circuits to be cleared of exhaled air.
Which machine is right depends on the needs of the person, taking into consideration the number of hours a day the ventilator will be used, the degree of assistance required, and the level of safety and types of alarms needed.
Most people who use ventilation more than 20 hours per day will want a second, usually identical, ventilator as a backup.
Types of interfaces
The type of interface to use is probably a more important decision for most vent users. Interfaces are broadly categorized as either "noninvasive" or "invasive." The tracheostomy tube, connected to an opening in the throat, is the only invasive method in routine use.
There are several options for noninvasive interfaces. "Once the decision is made to initiate mechanical ventilatory assistance," Warren says, "we spend much more time working with the various types of noninvasive mask-mouthpiece devices. This is where patient compliance and cooperation are focused.
"As a general rule, patients need several types of interface devices — nasal, oral, full face — in order to maintain an appropriate seal with different activities and at different times of the day or night."
Joshua Benditt, medical director of Respiratory Care Services at the University of Washington Medical Center in Seattle, says, "In almost all cases, at least part of the system is custom designed or adapted for the patient, most commonly the patient-ventilator interface."
| A nasal mask is a convenient way to deliver nighttime ventilation.
There are several options for a noninvasive interface, including simple mouthpiece, mouthpiece with lipseal, nasal mask, oronasal mask and nasal pillows. To use a mouthpiece, a person simply bites down on it lightly, seals his lips around it and allows the ventilator to do the rest.
A lipseal, somewhat like the mouthpiece used by boxers or football players, performs two functions. First, it prevents leakage of air around the lips, useful at night or when the facial muscles are weak. Second, it prevents tooth deformity, which can occur from long-term, constant use of simple mouthpiece ventilation.
Masks fit over the nose, or the mouth and nose together, to provide the seal needed. They are held on by Velcro straps that fit over the back of the head. Nasal masks don't prevent normal conversation, although masks covering the mouth do. Nasal pillows, really more like flexible rubber plungers that fit snugly against the nostrils, are held in place by straps as well.
Larry Homolka uses a mouthpiece during the day and a nasal mask at night. He shapes his mouthpiece to his liking by warming it on the stove, then squeezing it with a pair of pliers. To keep the mouthpiece within easy reach while he works or talks on the phone, he hooks the exhaust valve around his Medic-Alert chain. "It frees the hands," he says.
Ed White uses a variety of interfaces, including a nasal mask and an oronasal mask; at night, he uses nasal pillows. Rotating through a variety of masks helps prevent the skin irritation and breakdown that's sometimes seen at areas of excess pressure. Newer commercially available masks have been specifically designed to avoid these problems.
"Masks can be custom fitted, too," Benditt says. "This usually involves making a cast of the nose and upper lip that is then used to manufacture the rubber or plastic mask. Once this is done, the mask is fitted with adapters for holding it in place and attaching it to the ventilator." He also notes that some kits now allow a mask to be manufactured without using a mold.
Tracheostomy is another option for an interface, but one that comes with some significant disadvantages. The tracheostomy is an opening into the trachea, or windpipe. A tracheostomy tube is inserted into the opening, allowing the ventilator to pump air directly into the airways.
Oppenheimer says that tracheostomy is primarily for people with bulbar, or throat muscle, weakness. "People who are at risk for aspiration — passing food into the airways — can benefit from a tracheostomy, because they aren't as likely to aspirate with a trach in place."
Tracheostomy tubes can be fitted with an inflatable cuff that blocks off the top of the windpipe, preventing aspiration. However, Oppenheimer says, "Most people do better with uncuffed tubes, since they can push secretions up and out, and prevent putrefaction of unswallowed food above the cuff. Also, cuff inflation interferes with passage of air up to vocal cords needed for speech."
Although tracheostomies require a much higher level of care, Oppenheimer says, "Many doctors recommend tracheostomies for people who need more than 20 hours a day of mechanical ventilation." This isn't a firm rule, and there are some people who use noninvasive ventilation around the clock. For some people, though, the constant use of masks or mouthpieces is itself burdensome, and for others the tracheostomy feels safer or more reliable.
Another consideration with tracheostomy, says John Bach of the Department of Physical Medicine and Rehabilitation and co-director of the MDA clinic at New Jersey Medical School, is the strength of the assisted peak cough flow, a measurement of the air flow generated with the hardest cough a person can produce. If it's too weak — below 160 liters per minute — a tracheostomy may be better, since it allows direct access to the lungs for suctioning of secretions that coughing can no longer clear.
Airway secretions are one reason to avoid tracheostomy if possible, Warren notes. "The trach tube is an irritant to the airway. The irritation creates inflammation, which causes increased secretions," necessitating more secretion removal. Suctioning out those secretions can often lead to tears in the delicate airway lining, worsening the irritation and increasing secretions further.
"In addition," Warren continues, "this 'foreign body' in the airway becomes colonized with bacteria. During an acute respiratory illness, this particular bacterial organism may grow more rapidly, producing true respiratory infection." Pneumonia is much more common for people with trachs than for those using noninvasive ventilation.
The risk of infection can be minimized by daily attention to proper trach care. Benditt explains that this includes cleaning around the trach site and changing the dressing that surrounds the trach. This should be done at least once a day, or more often if there is skin irritation or excessive drainage. Good hand washing before and after is crucial. Keeping the skin dry around the opening is absolutely essential to maintain health of the skin. A bib may be used to keep the area dry during bathing.
Careful suctioning by someone trained in the proper procedure is also crucial, both to ensure adequate removal and to prevent damaging the airways. Lori Hinderer, who uses a trach, says her personal assistant's skill and attention has been the key to continued good respiratory health.
Hinderer has adapted her wardrobe to minimize the visual impact of the trach. "I purchase high-neck shirts and cut out a slit for around the trach. Another important wardrobe addition has been scarves. This simple adaptation has afforded me more self-esteem, as my hosing and trach are unnoticed."
Regarding the effect of a tracheostomy on speech, Oppenheimer notes, "There are lots of misconceptions about speaking with a trach. If you can speak before the tracheostomy, in almost all cases you'll be able to speak afterwards."
There are several options in this area. Uncuffed trachs allow air to move through the vocal cords. Cuffs can be deflated temporarily to allow speech. Hinderer uses a Passy-Muir valve, which routes air around the uncuffed trach tube. Finally, there are newer trach tubes specifically designed to assist speech.
Nonetheless, tracheostomies overall require significantly more care, and are more expensive, than a noninvasive interface. Warren says, "Most patients that have tracheostomies received them due to a 'crisis event,' without any thought or preplanning beforehand. It's my opinion, and studies have shown, that patients would not initially desire a tracheostomy if appropriate discussions about patient-machine interface are carried out."
Having a trach need not be an irreversible condition, however. Chris Arblaster had a tracheostomy in early 1997 following a respiratory crisis. In July of that year, his tracheostomy tube was removed by Bach and his team. Arblaster now uses nighttime noninvasive ventilation only. "I went from 24 hours a day to 7 hours only at night — I think that's pretty good," he says. His experience also serves as a cautionary tale about the value of planning ahead. It's likely that his crisis and tracheostomy could have been avoided with early discussion of ventilatory options.
There are other, less common, types of mechanical ventilation systems. One, the Pneumobelt, uses an inflatable sack strapped to the abdomen to apply pressure. This pushes air out of the lungs. When it deflates, gravity pulls the abdominal contents down, pulling air back in. The rocking bed uses a similar principle, tipping the head of the bed down to deflate the lungs, then tipping the foot down to reinflate.
Benditt has used Pneumobelts with many of his patients. "In appropriate individuals, I think it's terrific as an adjunct measure, in combination with other forms of ventilation." Bach also likes to consider the Pneumobelt, because "it optimizes appearance and leaves the mouth, nose and neck free." Benditt wishes there were quieter, smaller models available, since the equipment is noisy and bulky.
Cuirasses, or shell ventilators, are also available. These are rigid shells that strap over the chest and upper abdomen. Evacuation of the shell inflates the lungs, and repressurizing it deflates them.
Using mechanical ventilation
Whichever type of system is chosen, the goal is the same: to provide adequate ventilation to keep oxygen high and carbon dioxide low. Benditt explains, "Nocturnal ventilation should prevent any symptoms of chronic hypoventilation, including morning headache, drowsiness or disrupted sleep. If these symptoms are present, the ventilation settings may not be correct."
It's usually easy for vent users to tell if daytime settings are correct, or if they need more time on the ventilator, as long as they pay attention to their symptoms. "Patients are usually able to sense whether they are getting an appropriate volume of air just by feeling the inflation volume in their lungs," Warren says.
In addition, home monitoring of carbon dioxide, oxygen and expired volumes provides an objective check on the adequacy of the ventilation settings. White keeps daily records of his measurements to discuss with his pulmonologist. Settings are checked and adjusted as needed during clinic visits.
Homolka's ventilation system "works great" for him. "I never wake up because of breathing problems. I have a respiratory therapist who comes once a month to check the machine. She says my oxygenation is better than hers."
Like most vent users, Hinderer rents her equipment. "My company offers 24-hour service, many branch offices (helpful when traveling out of state) and professional respiratory therapists who take care of ventilator maintenance, supplies and any needs." The service also includes emergency response and equipment replacement.
To prepare for emergencies, all vent users should keep a resuscitation bag handy. The bag delivers air through a mask when it's squeezed.
Benditt and Bach also both recommend learning glossopharyngeal, or "frog," breathing. In this technique, the tongue and throat muscles are used to push air into the lungs. It's best learned by demonstration from someone who knows how. A second backup ventilator system is considered standard for people who use the ventilator 20 hours or more per day.
When Hinderer travels, she takes an extra ventilator, extra batteries, emergency numbers and a cell phone. She also has an adapter that powers her vent through a car cigarette lighter. When she flies, she first talks to a customer service representative at the airline, who contacts the shift supervisors on duty during her flight.
If there's one message everyone involved with mechanical ventilation agrees on, it's the importance of planning ahead, to begin to understand options before a crisis occurs. As Oppenheimer puts it, "You should get some experience, make some decisions ahead of time. It's much easier to try out noninvasive ventilation than a trach."
Benditt encourages his patients to talk with others who have made similar decisions. Bach offers patients his book, Guide to the Evaluation and Management of Neuromuscular Disease. He's edited another book on the subject as well, Pulmonary Rehabilitation: The Obstructive and Paralytic Conditions, both published by Hanley and Belfus.
Homolka notes that, "There's nothing noble about turning down medical opportunities, and the alternative is certainly worse. Sure, you constantly have to adapt. But I look at all this as positive, that we're able to get these machines. Since starting on mechanical ventilation, I've done more work and done more art shows than ever before. So there's a lot you can do with a ventilator."
MDA has published a 16-page booklet, "Breathe Easy: Respiratory Care in Neuromuscular Disorders," now available through local MDA offices. The text is written by Dr. Robert Warren, Dr. Vikki Stefans and respiratory therapist Sheila Horan, all with the Pulmonary Medicine Section, Department of Pediatrics, University of Arkansas for Medical Sciences.