Respiratory Management

There is currently no cure for CCHS, and treatment options are limited, for now. Researchers are actively studying the genetic and biological components of CCHS in hopes of discovering information needed for drug development.

The hallmark symptom of CCHS is impaired respiratory drive, which is managed solely by mechanical ventilation. Mechanical ventilation is a term used to describe machines that provide artificial breathing to ensure proper gas exchange in the body. It is technically a form of life support. Mechanical ventilation is required for CCHS patients whenever they are asleep and during wake hours for more complex cases. CCHS is lifelong which means weaning from mechanical ventilation is never a safe or realistic goal, regardless of age or severity. Devices commonly used in the respiratory management of CCHS include ventilators, BiPAP machines, and phrenic nerve pacers. The development of home ventilators and other bedside, portable therapies have directly improved quality of life for CCHS patients. They offer flexibility to travel, stay at a friends’ home, or live on-campus while in college. Families become accustomed to carrying all equipment and supplies anytime they leave the house. Ventilation, oxygen and carbon dioxide levels should be monitored. This can be done at home with a pulse oximeter and carbon dioxide end tidal machine. CCHS specialists also recommend “spot checks” of these levels throughout the day. Optimal oxygenation is between 95-100% and carbon dioxide levels should run between 30 to 50 mm Hg (ideally 35-40 mm Hg). Mechanical ventilation requires a dependable power supply. Families may want to consider purchasing a power generator in the event of an electrical outage or natural disaster. Placement on an emergency list for the local energy company and fire department ensures continuous care in the home.

It is also important to note that CCHS must be factored into treatment planning for all other medical conditions affecting the patient. For example, sedative and antihistamine drugs should be largely avoided as they can worsen hypoventilation. Surgical procedures should not be performed without an in-depth conversation with the anesthesiologist regarding CCHS risks. It is imperative that any treating clinician is made aware of the patient’s CCHS diagnosis and related implications.

MECHANICAL VENTILATION OPTIONS FOR CCHS

POSITIVE PRESSURE VENTILATION VIA TRACHEOSTOMY

The most common form of CCHS management, especially in the early stages, is positive pressure ventilation via tracheostomy. A tracheostomy tube is placed in a surgically constructed hole in the patient’s airway known as a stoma. This tube is connected to the ventilator circuit, which forces air into the lungs. The amount of air and pressure with each breath is determined by the patient’s age, size and disease severity. This approach is considered most reliable by many specialists as it offers direct access to the airway for proper ventilation and emergency intervention. It is also less cumbersome for parents/caregivers of a newborn, who must quickly attach the ventilator when their baby begins to fall asleep. There are complications with tracheostomies that need to be closely monitored. They introduce the risk of bacterial and viral infections that can spread to the lungs. Mucus plugs can also build up within the trach tube and obstruct airflow. Frequent suctioning is therefore required, especially during the first several years. Parents/caregivers need to be prepared for emergency situations that require immediate trach tube changes. They must also be educated on tracheostomy care, which requires cleaning of the stoma twice a day and weekly trach tube changes, as well as equipment maintenance.

BILEVELPOSITIVE PRESSURE (BIPAP) VENTILATION VIA MASK

BiPAP ventilation is considered non-invasive as it does not require surgical intervention. It provides artificial breathing through a face mask or in fewer cases, nasal prongs. The primary benefit of BiPAP is that a tracheostomy is not needed. Bilevel ventilation can be delivered through most home ventilators using specific settings or a smaller device designed for this mode of ventilation. BiPAP is different from CPAP as it provides both positive inspiratory and expiratory pressures. CPAP is commonly used for obstructive sleep apnea and is not an appropriate mode of ventilation for CCHS. Furthermore, clinicians must ensure proper BiPAP settings that guarantee the delivery of breaths for CCHS patients. A large portion of CCHS patients will transition from tracheostomy to BiPAP ventilation during childhood (typically after age 5), adolescence, or even adulthood. With that said, a small but growing number of mild newborn cases have been able to tolerate BiPAP via mask ventilation as initial therapy. Mask use was once thought to cause facial changes in young children however, newer masks have relieved some of this concern. One of the primary risks with BiPAP ventilation is air leakage from ill-fitting or detached masks or nasal prongs. Appropriate mask options must be considered (nasal, nasal and mouth, full face) and properly fitted by a respiratory therapist or trained specialist. Patients should always use a pulse oximeter as a back-up to ventilator alarms in the event of air leaks or other issues.

PHRENIC NERVE/DIAPHRAGM PACING

This form of ventilation entails surgical implantation of electrodes around the phrenic nerve in the neck or chest as well as a receiver. The phrenic nerve is critical in breathing as it controls the diaphragm. The electrodes connect to an external device that creates radio waves. These waves stimulate the nerve which causes the diaphragm to contract and the lungs to inhale. When the diaphragm relaxes, it allows for exhalation. Bilateral stimulation of the phrenic nerve (both sides) is strongly recommended for adequate ventilation in CCHS patients. Phrenic nerve stimulators are often recommended for complex patients who require prolonged ventilation beyond sleep. Pacers allow the patient to be ambulatory during the day then switch to a ventilator at night. There are also milder patients who prefer phrenic nerve stimulation over tracheostomy or mask ventilation due to its internal and compact design. Surgery can be complicated and requires an experienced cardiovascular-thoracic surgeon familiar with CCHS and the device. Patients and caregivers will need to be trained on the management and maintenance of the equipment, including an external antenna and transmitter that runs on batteries. Hospitalization is required for several days to weeks following the procedure. Like all CCHS patients, those with phrenic nerve stimulators must be monitored with routine checks of oxygen and carbon dioxide levels. Obstructive apnea can be a complication during sleep. Equipment failure is also a concern due to the risk of broken antennas, wires and electrodes.

Common Terms Used With Mechanical Ventilation:

Respiration/Breath Rate (RR): The number of breaths delivered in one minute.

Tidal Volume (TV): The volume of air that moves in a single normal inspiration or expiration.

Flow Rate: The amount of time to achieve tidal volume (TV).

Minute Ventilation (MV): The amount of air inhaled and exhaled in one minute.

Peak Inspiratory Pressure (PIP): The highest amount of pressure in the lungs when filled with air.

Positive End Expiratory Pressure (PEEP): The amount of pressure remaining in the lungs after expiration.

Volume Control Ventilation: The amount of air (TV) is guaranteed by the ventilator but not the pressure (PIP).

Pressure Control Ventilation: The amount of airway pressure (PIP) is guaranteed by the ventilator but not the amount of air (TV)

For information on other CCHS symptoms and related treatments, click here.