Mechanical Ventilation: Beyond the ICU

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Mechanical Ventilation: What Is It?

Mechanical ventilation is a method for using machines to help patients breathe when they are unable to breathe sufficiently on their own.

Most often, mechanical ventilation is used for a few days to help a patient breathe during a serious illness. This type of breathing support is usually done in an intensive care unit—an ICU for short.

Sometimes patients still can't breathe on their own after the acute illness is over, despite efforts to restore spontaneous breathing. Patients may no longer need to be in the ICU but still require mechanical ventilation because of an extended need for the breathing assistance of the ventilator.

Other patients may have stable, longer-term (chronic) conditions that make them unable to breathe on their own.

Due to a variety of reasons, including the cost of hospital care and the patient's quality of life, for the patient who is dependent on a ventilator for breathing assistance, it may be better to receive mechanical ventilation at home or at a nonhospital institution offering specialized nursing or rehabilitation services.

Over time, with the professional support of physicians and respiratory therapists, some ventilator-assisted individuals are able to become less dependent on the ventilator and breathe on their own for substantial portions of every day. Other patients have medical conditions that require 24-h mechanical ventilation for many months or years, or even for a lifetime.

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Ventilator Dependence

"Weaning" is the word used to describe the process of gradually removing the patient from the ventilator and restoring spontaneous breathing after a period of mechanical ventilation. Physicians and the ICU respiratory care specialists help patients to wean when weaning is determined to be medically appropriate. While patients with some conditions can be weaned from mechanical ventilation after a few days to a week in the ICU, patients with other conditions cannot or should not be taken off the ventilator. Patients with stable chronic medical conditions are more likely to require long-term mechanical ventilation, for example, patients with neuromuscular disorders or chest wall deformities.

Mechanical ventilation is required when a patient's spontaneous efforts are unable to sustain adequate ventilation of the lungs.

Conditions such as stroke and spinal cord injury damage the nerves that control breathing and make spontaneous breathing impossible for an extended period or for life.

Chronic stable illnesses, such as neuromuscular disorders and chest wall deformities, and/or advanced age, may make long-term mechanical ventilation necessary for extended periods or for life.

Chronic illness that requires recurrent ICU hospitalization may require frequent repeated treatments with mechanical ventilation and repeated attempts to wean from mechanical ventilation.

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Long-term Mechanical Ventilation: Who, When, and Where

Who

The patient's physician and respiratory care team determine (1) the need for long-term ventilatory assistance, and (2) the type of mechanical ventilation, both technique and equipment, best for the patient after discharge from the ICU.

These determinations are based on (1) the patient's current illness and past medical history, (2) complete medical assessment, and (3) tests of daytime, and sometimes of nighttime, breathing efficiency and ability to breathe without help.

Patients who benefit from long-term mechanical ventilation are those whose medical conditions would become unstable if they were removed from mechanical ventilation. They might have recurrent or chronic conditions that make it more difficult for the patient to carry out activities of daily living.

When

Medical criteria determine when a patient can be discharged from the ICU on long-term mechanical ventilation to a site outside the ICU. However, other considerations also are important. Successful discharge on long-term mechanical ventilation is more likely when:

• the patient is highly motivated to accept the responsibility to make long-term ventilation work;
• the patient may be able to independently do some activities of daily living;
• the patient is able to communicate with caregivers and give them direction;
• the patient and his/her family understand all available options for long-term ventilation;
• the family is able and willing to participate in long-term care;
• financial resources are available for mechanical ventilation equipment and caregiver assistance such as nursing services; and
• medical and respiratory care professionals are available to monitor and supervise long-term care.

Where

The optimal location for long-term ventilator-assisted individuals may be with the family in the home. In the home, the patient's quality of life is likely to be better than at any other location. Costs of care are usually lower when the patient is at home, but insurance coverage of home-care costs must be evaluated on an individual basis to determine if adequate reimbursement is available. Usually, the cost of home care must be less than the cost of a long-term care facility in order for benefits to apply.

Home is not the only site for patients to receive long-term mechanical ventilation. Other non-hospital sites may be appropriate for the patient's needs and resources. The appropriate site for long-term mechanical ventilation is one in which all of the patient's needs—medical care, respiratory care, psychological support, and rehabilitation—can be met by available resources. A site other than the home may be more appropriate for some patients.

The choice of a site for long-term mechanical ventilation is a joint responsibility of the patient, patient's family, and patient's physician, with consultation from other members of the respiratory care team—respiratory therapist, nurse, social worker, case manager, and benefits manager.

Types of Facilities That May Be Considered:

For patients who can leave the ICU but still require hospitalization:

• Specialized respiratory care unit of the hospital
• General medical/surgical unit of the hospital

For patients who can leave the hospital but have special needs for care, monitoring, or rehabilitation:

• Subacute care unit of the hospital
• Long-term care hospital
• Rehabilitation hospital

For patients capable of some degree of independent living:

• Skilled nursing facility
• Congregate living center
• Home

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Mechanical Ventilation: Methods

The method of long-term mechanical ventilation that is best for the patient will be determined by the physician, respiratory therapist, and the patient. A patient capable of some independent activities and several hours a day off the ventilator will have different requirements than the patient who needs ventilator assistance 24 h a day.

Invasive methods use a tracheostomy—a surgical hole in the windpipe through which a tube is channeled to assist breathing.

Noninvasive methods use masks, nasal tubes, and other techniques that do not require surgical entry into the respiratory tract. Some apply positive pressure to the mouth and/or nose. Others apply negative pressure to the chest or body by lowering the pressure outside the body.

All methods of ventilation require an initial assessment of comfort and efficacy and follow-up monitoring of daytime and nighttime breathing. The patient and caregivers should be educated in use and maintenance of the equipment needed to provide the support.

Noninvasive Methods

• Positive Pressure Ventilation: Mouth and/or Nose

Positive pressure ventilation delivers air (and sometimes extra oxygen when medically necessary) to the patient through a face mask, mouthpiece, or nasal mask. Patients who can be independent of the ventilator for portions of the day may use noninvasive positive-pressure ventilation to assist nighttime breathing.

• Negative Pressure Ventilation

Entry of air into the lungs is assisted by applying intermittent negative pressure (like a vacuum) to the chest and abdomen by means of a body tank (iron lung), a chest shell, or a body jacket.

• Rocking Bed

A bed with rocking motion assists ventilation by intermittently causing the diaphragm to move up and down, creating a "pumping" motion in the chest, and thus, helping air to go in and out of the lungs.

• Pneumobelt

An inflatable band around the abdomen presses on the abdomen and forces air in and out of the lungs. The pneumobelt may be used in combination with other noninvasive methods of ventilation. It may not be suitable for some patients—for example, patients who are excessively underweight or overweight. The patient must be sitting up for this device to work. It is often used by patients in a wheelchair.

• Diaphragm Pacing

An electronic pacer stimulates the diaphragm to contract, thus assisting breathing by "bellows" motion of the diaphragm. This method is used by patients who have high (C1-C2) spinal cord injury, and with tracheostomy in some children who cannot breathe spontaneously because of a problem with central control of breathing.

• Glossopharyngeal Breathing

Sometimes called "frog" breathing—a technique in which the patient learns to "gulp" air into the lungs. Some patients use this technique in order to spend more time off the ventilator and to have "free" time in case of ventilator failure.

• Manually Assisted Coughing

A caregiver helps the patient to exhale and clear mucus from the lungs by delivering a thrust similar to a Heimlich maneuver. Thorough training of the patient and caregivers is required to make this technique effective and to avoid injury to the patient.

Invasive Methods

Invasive methods may be needed for patients who are unable to use noninvasive methods. Invasive mechanical ventilation requires a tracheostomy for placement of a tracheostomy tube into the windpipe to deliver air directly into the lungs. The patient and caregivers are trained in care of the tracheostomy and tube to prevent complications such as infection around the tracheostomy tube or clogging of the tube.

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Discharge Management Plan

Before a ventilator-assisted individual is discharged from the hospital to home or a long-term care institution, the patient and all caregivers (1) must be trained in all aspects of long-term mechanical ventilation, and (2) must show the physician and health-care team that they have learned to carry out all care techniques.

A written discharge plan should be provided and should include:

• names and telephone numbers of the primary physicians;
• address and telephone number of the local hospital emergency department;
• address and telephone number of the physician for regular check-ups;
• the responsibilities of the patient in daily care;
• the responsibilities of caregivers in daily care;
• identification of financial resources for long-term care;
• identification of community resources for health, social, educational, and vocational needs;
• an itemized list of all equipment and supplies needed for long-term mechanical ventilation;
• names, addresses, and telephone numbers of mechanical ventilation equipment dealers and a list of services they provide; and
• contingency plans for emergency situations.

The physician and health-care team will arrange a schedule for follow-up visits as indicated by the needs of the patient.

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Equipment and Resources

A wide array of equipment and supplies is needed for long-term mechanical ventilation at home or other site.

The table provides a checklist of equipment and supplies.

Some of the supplies may not be needed by every patient. For example, a patient on noninvasive ventilation would not need a tracheostomy tube adaptor or tracheostomy supplies unless the physician believes the supplies are medically necessary.

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Mechanical Ventilator

Portability

A small ventilator mounted on a wheelchair or cart can enable a ventilator-assisted individual to be more mobile, and therefore, more independent. Travel away from home for a day or more requires special arrangements, such as oxygen supplies en route, a portable power source for the ventilator, and advance arrangements for any emergency situations.

Power Sources

Most ventilators operate on regular household electrical current. A 12-volt battery should be readily available for use as an interim power source during a short-term power outage and should be checked weekly to make sure it is fully charged. The 12-volt battery also can be used to power a wheelchair-mounted ventilator. A backup electricity generator may be needed in remote areas where power outages can be prolonged; the backup generator should be operated at least once a month to make certain it is ready for any emergency.

Ventilator Circuits

Nondisposable ventilator circuits are less expensive than disposable types, but regular cleansing every 7 to 10 days is necessary: thorough washing with dishwashing detergent and water, disinfection with vinegar and water solution, followed by thorough clean water rinse and thorough drying in open air.

Humidification

All patients receiving continuous mechanical ventilation by tracheostomy should have warmed, humidified inspired air. Patients receiving noninvasive ventilation may need humidification of inspired air in dry climates or during dry winter months.

Oxygen

Medical assessment of the patient determines whether supplemental oxygen should be added to air delivered by mechanical ventilation. Tank oxygen must be available as needed and for emergencies.

Suctioning

A suction machine and supplies may be needed to regularly remove secretions from the patient's airway, especially for the patient with a tracheostomy. A member of the health-care team should teach caregivers how to suction using clean techniques to avoid infection.

Alarms

Ventilators, especially for patients with a tracheostomy, should have alarms to signal high or low air pressure changes, breathing problems of the patient, ventilator malfunction, and power failure. An alarm must be available for the patient to call for assistance.

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Patient Communication System

Speech may not be possible for some patients, especially those on invasive ventilation. Alternative methods of communication are then required—for example, electronic larynx, computer terminal, or pad and pencil. Communication devices are desirable both for quality of life and for safety.

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Equipment Supplier

The firm that supplies mechanical ventilation equipment should offer 24-h emergency repair and maintenance service and an equipment inventory adequate to service equipment failure.

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Long-term Mechanical Ventilation in Infants and Children

When infants and children require long-term mechanical ventilation at home or at a long-term care facility, their needs differ from those of adults in many respects.

Goals for long-term mechanical ventilation of children include:

• maximizing the child's opportunity for growth and development;
• preparing the child for rehabilitation; and
• optimizing the child's quality of life.

Mechanical ventilation of the infant and child must be planned with the child's future in mind—schooling, playtime, socialization. A method of mechanical ventilation must be selected individually for every child.

Around-the-clock responsibility is an especially difficult issue for caregivers of a child being mechanically ventilated at home. While the child usually receives maximum care and attention, caregivers (parents, siblings, relatives) often experience substantial stress due to physical, psychological, and emotional demands. Caregivers may find it useful to join a support group that includes people facing similar situations. The patient's physician and members of the health-care team can help the caregivers obtain professional counseling, if needed.

Copyright © 1999 by the American College of Chest Physicians