2005 OPEN FORUM Abstracts
CAN HIGH FREQUENCY CHEST WALL OSCILLATION WORSEN PULMONARY STATUS IN CHILDREN WITH SEVERE NEUROLOGICAL IMPAIRMENT AND INEFFECTIVE COUGH?
Denise Willis, RRT-NPS, Robert Warren, MD. Arkansas Children's Hospital, Little Rock, AR.
High frequency chest wall oscillation (HFCWO) is a mode of airway clearance used to treat a variety of pulmonary diseases and conditions. The vest system is one type of HFCWO which has proven to be effective in the treatment of cystic fibrosis but has not been widely studied in other diagnoses such as cerebral palsy. The vest system works to loosen and mobilize airway secretions by rapidly inflating and deflating to produce chest compression. Although highly effective in mobilizing mucus, the vest does not assist in removing mucus from the lungs.
Parental report describes 3 children with severe neurological impairment and ineffective cough who experienced adverse effects after administering HFCWO with a vest system. "A" is a 12 year old male who suffered an anoxic episode at 6 weeks of age resulting in cerebral palsy, seizures and severe developmental delay. His first pulmonary visit occurred at 11 years for a surgical evaluation for scoliosis repair. At that time he demonstrated a hypopneic breathing pattern with a resting tidal volume of only 3.6ml/kg. He was also noted to have an ineffective cough with inability to clear secretions. He was prescribed a vest and mechanical insufflator-exsufflator (MI-E). The MI-E was denied by insurance so only the vest was begun. Two months later he was admitted to the PICU for aspiration versus mucus plugging. The mother reported an event which occurred during vest therapy in which large amounts of secretions were produced followed by desaturation and respiratory distress. Following a 2.5-month hospital stay, he was discharged with nocturnal non-invasive mechanical ventilation and a MI-E. He continues to receive vest treatments, however now followed by MI-E and is tolerating this regimen well. "B" is a 10 year old male who was a 32 week ex-preemie admitted to the hospital at 9 days of age for Group B Streptococcus and sepsis which lead to anoxic brain injury, severe developmental delay, seizures and resultant cerebral palsy. At 9 years he was prescribed vest therapy because of recurrent pneumonia and chronic aspiration. Four months later his mother stated the vest "made him worse" and requested it be discontinued. Large amounts of secretions were being produced that he was unable to remove with coughing. A MI-E was recommended but declined by the mother. "C" is a 5 year old male who was a term newborn with meconium aspiration syndrome requiring ECMO. He suffered an anoxic event due to prolonged hypoxemia and consequential cerebral palsy, severe developmental delay and seizures. His first pulmonary evaluation occurred at 14 months of age. Manual CPT was being performed at that time. The primary care physician ordered a vest system at 4 years. At a pulmonary visit 3 months following initiation of vest therapy, the parents stated he was "drowning in secretions" during treatments. A MI-E was prescribed and is now used in conjunction with the vest without secretion problems.
In severe cerebral palsy, normal airway clearance is often compromised due to limited mobility and inadequate cough. A stimulus to cough may exist in these children but they may be unable to produce an effective cough because of neurological impairment. A weak or absent cough effort interferes with the ability to clear secretions from the airways and can result in aspiration, pneumonia, atelectasis and recurrent respiratory infections. HFCWO with a vest system has been shown to be effective in preventing recurrent infections. However, in the absence of an effective cough, additional devices such as the MI-E may be required as an adjunct.