Annotated Bibliography: Clinical Research

Acute Care/ICU/Post-Surgical

Pulmonary complications arising from transient impairment of mucociliary clearance and cough function are common in post-surgical/ acute care patients. Retained secretions promote development of atelectasis, bronchopulmonary infections, pneumonia and respiratory failure. Such complications are a major factor in driving up total healthcare costs, especially in terms of intensive care unit utilization.

1. Allen JS, Garrity JM, Donohue DM. The utility of high-frequency chest wall oscillation therapy in the post-operative management of thoracic patients. Abstract: Control/Tracking Number: 03-A-732-ACCP.
In a safety and tolerance assessment of high frequency chest compression (HFCC) in post-operative secretion management, 25 elective thoracic surgical patients received HFCC as soon as 24 hours after surgery. Pre and post HFCC treatment, hemodynamic and pulse oximetric values remained stable; 84% of patients tolerated and accepted the therapy; no major adverse events were observed. HFCC may be a safe, cost-effective intervention for prevention or management of post-operative pulmonary complications for appropriately selected patients.

2. al-Saady NM, Fernando SS, Petros AJ, Cummin AR, Sidhu VS, Bennett ED. External high-frequency oscillation in normal subjects and in patients with acute respiratory failure. Anaesthesia 1995; 50:1031-1035.
Twenty healthy volunteers treated with an external chest wall oscillation (ECWO) device (the Hayek Oscillator) demonstrated significant improvement in lung ventilation. Effective ventilation was measured in terms of the fall in alveolar PCO2 immediately after oscillation. In the same study, ECWO was compared with intrapulmonary positive pressure ventilation (IPPV) in five patients with respiratory failure. After a 30 minute treatment with IPPV, therapy was replaced with 30 minutes of ECWO. Oxygenation improved by 16% and PCO2 decreased by 6%, indicating that ECWO can maintain adequate ventilation is this group of patients.

3. Brierley S, Adams C, Suelter J, Gooch T, Becker B. Safety and tolerance of high-frequency chest wall oscillation (HFCWO) in hospitalized critical care patients. Respir Care 2003; 48 (11): 1112.
In an observational study of the safety and tolerance of high frequency chest compression (HFCC) therapy in acute care patients, 73 critical care/post-surgical patients were treated with HFCC concurrently with therapies or equipment including 1) sternal incision/sternal wires ( n = 48); 2) chest tubes ( n=24); 3) external pacer wires ( n=30) ; 4) swan-ganz catheters ( n =27); 5) penrose drains (n= 23); 6) central venous pressure lines (n=21); 7) implanted cardiac pacemakers (n= 11); 8); CPAP (n= 5); 9) mechanical ventilation (n=1);10) internal cardiac defibrillator (n =1). A total of 179 therapy days were evaluated. HFCC was well tolerated by 84% of users; 16% discontinued citing discomfort. No significant adverse events were reported. With appropriate care, HFCC use in this patient population appears to be safe, well-tolerated and unlikely to dislodge or disrupt invasive or sensitive equipment.

4. Chiappetta A, Mendendez A, Gozal D, Kiernan M. High-frequency chest wall oscillation in hospitalized non-cystic fibrosis patients. Am J Respir Crit Care Med 1996; 153:A56.
A retrospective medical chart review of 300 hospitalized non-cystic fibrosis patients (diagnoses unspecified) receiving professionally administered percussion and postural drainage (P& PD) treatments for secretion clearance found that a significant proportion of those treatments could have been effectively replaced with high frequency chest compression (HFCC), thus providing a substantial savings in professional time, effort and costs.

5. Gomez A, Elisan I, Hardy K. Utilization of high frequency chest wall oscillation (Vest therapy) during therapeutic pediatric flexible fiberoptic bronchoscopy. Poster presentation at the 46th International Respiratory Congress of the American Association for Respiratory Care, October 7, 2000, Cincinnati, Ohio, USA.
This report of the use of high frequency chest compression (HFCC) in three pediatric patients in conjunction with fiberoptic broncoscopy showed marked enhancement of secretion clearance in two of the three during the procedure. No safety concerns were noted.

6. Gomez A, Elisan I, Hardy K. High frequency chest wall oscillation: video documentation of effect on a patient with Duchenne muscular dystrophy and severe scoliosis. Presented at the 46th International Respiratory Congress of the American Association for Respiratory Care, October 7, 2000, Cincinnati, Ohio, USA.
A 16 year-old Duchenne muscular dystrophy patient with severe kyphoscoliosis and deteriorating respiratory health had persistent atelectasis and mucus plugging unresponsive to both manual chest physiotherapy (CPT) and therapeutic bronchoscopy. A subsequent bronchoscopy performed while the patient received high frequency chest compression (HFCC) successfully cleared large volumes of secretions. A follow-up videotaped broncoscopy with HFCC showed healing bronchial mucosa, minimal secretions and significant mobilization for mucus from peripheral lung regions.

7. Gomez A, Acker R, Buehler C, Newman V, Successful use of high frequency chest wall oscillation in pediatric post operative spinal fusion. Presentation at the 48th International Respiratory Congress of the American Association for Respiratory Care, AARC 2002 Abstract; OF-O2-156.
A retrospective hospital chart review is reported for four adolescent spinal fusion patients (idiopathic scoliosis) in a pediatric intensive care unit (PICU) who received high frequency chest compression (HFCC) 3-5 days post-operatively after failing other airway clearance interventions. Indications were atelectasis with or without pleural effusion and with or without evidence of mucus plugging. All patients had either inadequate cough secondary to post operative pain, an artificial airway for ventilatory support and/or neuromuscular disease. HFCC was administered for 20-30 minutes every 2-4 hours. Radiographs after 4 days of HFCC for all patients showed either complete resolution or minimal residual atelectasis.

8. Ndukwu IM, Shapiro S, Nam AJ, Schumm PL. Comparison of high-frequency chest wall oscillation (HFCWO) and manual chest physiotherapy (mCPT) in long-term acute care hospital (LTAC) ventilator-dependent patients. Chest 1999; 116 (4) Suppl: 311S.
This randomized, controlled study of 54 long-term acute care patients who had been ventilator-dependent for a median of 84 days compared chest physiotherapy (CPT) and high frequency chest compression (HFCC) as modalities for secretion management. Subjects were randomized to receive either CPT or HFCC 4 times daily for 15 minutes for 40 days. After 21 days, the HFCC group produced larger volumes of sputum and, after 40 days, 38 % were weaned from ventilator dependence compared with 15% in the CPT group. No adverse events occurred, suggesting that HFCC is safe, effective and may promote ventilator weaning.

9. Whitman J, Van Beusekom R, Olson S, Worm M, Indihar F. Preliminary evaluation of high-frequency chest compression for secretion clearance in mechanically ventilated patients. Respir Care 1993; 38:1081-1087.
A comparison of the safety and efficacy of percussion and postural drainage (P&PD) and high frequency chest compression (HFCC) in the treatment of long-term mechanically ventilated patients showed equivalent safety and efficacy; 80% of therapists believed HFCC reduced work load.

Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS), a progressive, fatal neurodegenerative disease, has no known cause and few effective treatments. Patients with advanced disease are unable to clear airway secretions effectively; most die of respiratory failure following recurrent, increasingly severe episodes of pneumonia.

1. Chaisson KM, Walsh S, Simmons Z, Vender RL. A clinical pilot study: High frequency chest wall oscillation airway clearance in patients with amyotrophic lateral sclerosis. ALS 2006; 7 (2): 107-111.
This single center study evaluates the effectiveness of high frequency chest compression (HFCC) when added to standard care in preventing pulmonary complications and prolonging the time to death in patients with ALS. Nine patients with a diagnosis of ALS and concurrently receiving non-invasive ventilatory support with bi-level positive airway pressure (BiPAP) were randomized to receive either standard care or standard care plus the addition of HFCC twice-daily for 15 minutes. The addition of HFCC did not significantly improve time to death compared to standard treatment alone (340 days +/- 247 vs. 470 days +/- 241; p = 0.26); effects on pulmonary function were non-significant. Investigators comment that this study does not exclude the potential benefit of HFCC in select patients with ALS who have co-existent pulmonary diseases, pre-existent mucus-related pulmonary complications, or less severe levels of respiratory muscle weakness.

2. Jackson CE, Moore D, Kittrell P, Ensrud, E. High-frequency chest wall oscillation in amyotrophic lateral sclerosis. J Neuromusc Dis 2006; 8(2): 60-64.
In this three month retrospective chart review to evaluate the effectiveness of high-frequency chest compression (HFCC) therapy in 18 patients with amyotrophic lateral sclerosis (ALS), pre-treatment and post-treatment data including ALS Functional Rating Scale-Revised (ALSFRS-R), forced vital capacity (FVC), maximal inspiratory pressure (MIP), peak cough expiratory flow (PCEF), and daytime oximetry were compared. Daytime oximetry increased for 8 of 18 patients; none of the other measures changed significantly although the change in slope of FVC, MIP, and PCEF following initiation of treatment suggested a reduction in the rate of decline of each measure. Patient survey results reported that 92% felt better after HFCC therapy and breathing was easier; 85% agreed that HFCC eased secretion clearance and improved their quality of life.

3. Lange DJ, Lechtzin N, Davey C, David W, Heiman-Patterson T, Gelinas D, Becker B, Mitsumoto H, and the HFCWO study group. High-frequency chest wall oscillation in ALS: An exploratory randomized controlled trial. Neurol 2006; 67: 991-997.
This 12-week randomized controlled trial to evaluate changes in respiratory function in ALS patients after using high-frequency chest compression (HFCC) showed that the HFCC users (19) had less breathlessness (p = 0.021) and better nocturnal cough function (p = 0.048) at 12 weeks compared to baseline. Non-users (20) reported more noise when breathing (p = 0.027); those with FVC between 40 and 70% predicted showed a significant mean decrease in FVC; HFCC users showed stable FVC and significantly less increased fatigue and breathlessness. 79% reported satisfaction with HFCC.

Asthma

A subset of asthma patients are unresponsive to routine therapies and experience acute, severe, even life-threatening exacerbations. Ongoing bronchospasm, inflammatory edema, and mucus plugging critically diminish airway diameter and initiate a cascade of events including hypoxia, hypercapnia, acidosis, lung hyperinflation, increased work of breathing, and ventilatory muscle fatigue; life-threatening cardiovascular depression and respiratory arrest may ensue. In fatal cases, mucus plugging is a routine post-mortem finding.

1. Koga T, Kawazu T, Iwashita K, Yahata R. Pulmonary hyperinflation and respiratory distress following solvent aspiration in a patient with asthma: expectoration of bronchial casts and clinical improvement with high-frequency chest wall oscillation. Respir Care. 2004 Nov; 49(11):1335-8.
This case report describes the experience of an 18-year old man with status asthmaticus following accidental inhalation of toluene. The patient presented with severe dyspnea, did not respond to standard treatment [(including chest physiotherapy (CPT)] and deteriorated rapidly. Symptoms included a sharp decline in oxygen saturation, rapid, shallow breathing, profuse sweating, and activation of accessory respiratory muscles. Combined treatment with high frequency chest compression (HFCC) for airway clearance and BiPAP for ventilatory support resulted in expectoration of a large bronchial cast followed by copious volumes of mucus and additional casts. Authors suggest that HFCC may have been effective in this patient because of its ability to reduce the viscoelastic and cohesive properties of mucus and to enhance clearability by inducing a cephalad airflow bias in obstructed or plugged airways.

2. Krishnan JA, Spencer L, Schmidt, L, Bilderback MS, and Diette GB MD, MHS. Feasibility of High Frequency Chest Wall Oscillation (HFCWO) for Treatment of Asthma Exacerbations. Chest 2004; 126 (4): 721S.
This randomized, controlled, double-blinded trial compared active and sham device high frequency chest compression (HFCC) treatments (15 minute treatments, 3X daily) in eight patients hospitalized with asthma exacerbation. Outcomes for adherence, comfort, and perceived benefit were assessed after 4 treatments. Adherence to HFCC was high (mean 98.1%; range 87% -100%). 100% of participants agreed that the therapy was both comfortable and beneficial.

3. Naviaux W, Stamey D, Redding G. Factors altering airflow during high-frequency chest wall compression in normal and asthmatic subjects. Am J Respir Crit Care Med 1998; 157 (Suppl 30): A630.
In this study of oscillatory airway flow measured at the mouth during high frequency chest wall compression (HFCC), both normal and asthmatic subjects with significant airway disease showed increased airflow with the addition of inhaled Heliox (30% O2 -70% He mixture) over that achieved when subjects breathed room air. Data suggest that Heliox inhalation during HFCC treatment may augment mucus clearance in some patients.

4. Wen AS, Woo MS, Keens TG. Safety of chest physiotherapy in asthma. Am J Respir Crit Care Med 1996; 153 (Suppl): A 77.
In this randomized crossover study, 13 asthma patients received either nebulized bronchodilator (NB) treatment or NB plus high frequency chest compression (HFCC) on different days. No episodes of bronchiospasm occurred, suggesting that HFCC administered in conjunction with NB may be used safely in patients with asthma.

Bronchiectasis

Bronchiectasis is a term for irreversible lung damage resulting from recurrent episodes of infection and inflammation triggered by any disease or condition complicated by mucus hypersecretion and/or retention. Clinical symptoms include daily copious sputum production, chest pain and shortness of breath associated with airflow limitation and recurrent respiratory infections. Progression is marked by increasingly frequent, severe episodes of exacerbation.

1. Silverman E, Ebright L, Kwiatkowski M, Cullina J. Current management of bronchiectasis; review and 3 cases. Heart Lung; 2003; 32 (1): 59-64.
Three case reports describe secretion management in bronchiectasis patients using a combination or airway clearance interventions including high frequency chest compression (HFCC). Although the contribution of HFCC to the significant improvement of all three patients cannot be quantified, the therapy is judged "…equally safe and effective when compared to CPT during acute pulmonary exacerbations, with the advantage of being easier to administer, less expensive, and less time consuming."

Chronic Obstructive Pulmonary Disease (COPD)

Chronic obstructive pulmonary disease (COPD) is an umbrella term for a spectrum of chronic respiratory disorders characterized by symptoms including airflow limitation, impaired gas exchange, dyspnea and tissue inflammation. Functional and structural mucociliary impairment is characteristic; increased sputum production is common but not universal.

1. Beck GJ. Chronic bronchial asthma and emphysema: Rehabilitation and use of thoracic vibrocompression. Geriatrics, 1966; 21: 139-158.
In this earliest known clinical application of HFCC, the inventor/clinician described equipment consisting of an air pulse generator that delivered positive pressure of 30 cm H2O from a compressor passed over a vibrator operating at 30 Hz and applied to the upper abdomen and lower thorax with a thoracoabdominal belt. Outcomes include significant mucus expectoration, marked reduction of dyspnea and temporary or sustained benefit in severely obstructed patients.

2. George RJ, Winter RJ, Flockton SJ, Geddes DM. Ventilatory saving by external chest wall compression or oral high-frequency oscillation in normal subjects and those with chronic airflow obstruction. Clin Sci (Lond). 1985; 69:349-359.
Oscillation of the air within the lungs at high frequency is associated with an increased clearance of CO2. In this study, high-frequency oscillations were superimposed upon tidal breathing by using a loudspeaker attached to a mouthpiece to produce oral high-frequency oscillation (OHFO) or by external chest wall compression (ECWC). Changes in ventilation and breathlessness using OHFO and ECWC in normal subjects were compared with those in patients with chronic airflow obstruction (CAO). The pattern of breath conservation was then related to the resonant frequencies of the respiratory system as a whole (5-10 Hz in normal subjects, 16-26 Hz in CAO) and those of the ribcage (70 Hz). OHFO reduced minute ventilation (VE) by up to 46% in normal subjects (P = < 0.01) and 29% in CAO (P = < 0.01) without any rise in CO2. ECWC reduced VE by 27% in normal subjects (p = < 0.01) and 16% in CAO (p =< 0.01) without a rise in CO2. High-frequency oscillation by either method relieved breathlessness in those with CAO, was comfortable and well tolerated and may have value as a supplement to ventilation.

3. Perry RJ, Man GCW, Jones RL. Effects of positive-end expiratory pressure on oscillated flow rate during high-frequency chest compression. Chest 1998; 113 (4): 1028-1033.
A comparative study of six normal subjects and six with stable COPD showed that, in the COPD group, the addition of a small amount of positive end expiratory pressure (PEEP) during HFCC therapy prevents decreased end-expiratory lung volume and increases mean oscillated flow rate during both phases of spontaneous breathing. The higher oscillated flow rates achieved during HFCC+PEEP may improve the effectiveness of HFCC in clearing mucus from the lungs of patients with airway disease.

4. Piquet J, Brochard L, Isabey D, De Cremoux H, Chang HK, Bignon J, Harf A. High frequency chest wall oscillation in patients with chronic airflow obstruction. Am Rev Respir Dis 1987; 136:1355-1359.
This study of 12 patients with severe COPD showed that high-frequency chest compression (HFCC) administered during expiration resulted in decreased respiratory rate, increased tidal volume, increased arterial PO2, decreased arterial PCO2, and decreased duty cycle (time of inspiration/total breath period). Results suggest that HFCC may facilitate inspiratory muscle work and enhance both gas exchange and inspiratory muscle function. The potential of HFCC to strengthen respiratory muscle function and improve ambulatory care in patients with severe COPD merits further investigation

5. Rumbak MJ, Marchione VL, Kennedy TC, Rolfe MW. Ninety-day assessment of the effect of high-frequency chest wall oscillation (HFCWO) on exercise tolerance and quality of life of patients with chronic obstructive pulmonary disease. Chest 2001; 120:4(Suppl): 250S. (Presented at ACCP Chest Conference, November 2001).
In a 90-day trial of high frequency chest compression (HFCC), COPD patients that completed the trial program and then elected to continue HFCC therapy experienced statistically and/or clinically significant improvements in treatment and quality-of-life outcomes measured by validated instruments. Outcome domains include: 1) dyspnea; 2) six-minute walk distance; 3) quality of life (general health category); 4) treatment satisfaction and; 5) treatment adherence.

Cystic Fibrosis

Cystic fibrosis (CF) is an inherited disorder characterized by abnormalities in mucus secretion and clearance. Secretions accumulated in the airways harbor infectious organisms and initiate a cascade of events leading to a vicious cycle of progressive lung disease, respiratory failure and ultimately, death. Lifelong daily airway clearance therapy is universally prescribed as medically necessary for all CF patients.

1. Anbar RD. Compliance with use of ThAIRapy® Vest by patients with cystic fibrosis. Pediatr Pulmonol 1998; (suppl 17):346, A497.
Eighty-two patients using high frequency chest compression (HFCC) for more than six months were evaluated retrospectively for compliance. Analysis of data recorded by a meter installed in the device showed fairly constant compliance over the first several months of therapy.

2. Anbar RD, Powell KN, Iannuzzi DM. Short-term effect of ThAIRapy® Vest on pulmonary function of cystic fibrosis patients. Am J Respir Crit Care Med 1998; 157(suppl 3):A130.
A retrospective chart review of 54 cystic fibrosis patients receiving daily high frequency chest compression (HFCC) therapy showed an aggregate average FEV1 improvement of 8% when compared with their best pulmonary function test (PFT) results obtained 0-6 months prior to initiation of HFCC. Patients receiving regular CPT prior to initiation of HFCC therapy (61%) showed FEV1 improvements averaging 7% compared to average improvements of 11% for patients receiving no regular pre-HFCC airway clearance therapy (39%).

3. Anbar RD. Use of ThAIRapy Vest does not affect liver function of patients with cystic fibrosis. Am J Respir Crit Care Med 1999; 159(3), A687.
A retrospective chart review of liver enzyme levels for 77 consecutive patients receiving short-term high frequency chest compression (HFCC) therapy showed no evidence of an adverse effect on liver function.

4. App EM, Lohse P, Matthys H, King M. Physiotherapy and mechanical breakdown of the excessive DNA load in CF sputum-an anti-inflammatory therapeutic strategy. Pediatr Pulmonol 1998; (suppl 17):349, A507.
Results of this study evaluating the effects of high-frequency oscillations on the breakdown of high-molecular-weight DNA in cystic fibrosis (CF) sputum samples suggest that such oscillations can break down DNA as effectively as rhDNAse treatments. Reductions in intact DNA are estimated at approximately 15% after 30 minutes of treatment.

5. Arens R, Gozal D, Omlin KJ, Vega J, Boyd KP, Keens TG, Woo MS. Comparison of high-frequency chest compression and conventional chest physiotherapy in hospitalized patients with cystic fibrosis. Am J Respir Crit Care Med 1994; 150:1154-1157.
Fifty CF patients hospitalized for acute pulmonary exacerbation were randomly assigned to therapy with either HFCC or CPT three times daily. Clinical status and pulmonary function tests (PFT) were similar for both groups at admission. After 7 and 14 days of treatment with either intervention, both groups showed significant but similar improvements in clinical status and PFT scores and comparable time to discharge. HFCC and professionally administered CPT are judged equally safe and effective for secretion management during acute pulmonary exacerbations in CF patients.

6. Braggion C, Cappelletti LM, Cornacchia M, Zanolla L, Mastella G. Short-term effects of three chest physiotherapy regimens in patients hospitalized for pulmonary exacerbations of cystic fibrosis: a cross-over randomized study. Pediatr Pulmonol 1995; 19:16-22.
This randomized cross-over trial compared the short-term efficacy of three physiotherapy modalities - postural drainage (PD), positive expiratory pressure (PEP) therapy, and high-frequency chest compression (HFCC) - in 16 cystic fibrosis patients hospitalized for acute exacerbation. Subjects received a control session and randomized 2-day trials of each study modality. Results of sputum volume assays (wet and dry weight) and lung function scores (FEV1, FVC, and FEF) were similar for all three regimens.

7. Burnett M, Takis C, Hoffmeyer B, Patil S, Pichurko B. Comparative efficacy of manual chest physiotherapy and a high-frequency chest compression vest in inpatient treatment of cystic fibrosis. Am Rev Respir Dis 1993; (suppl 147):A30.
This randomized controlled trial compared chest physiotherapy (CPT) and high frequency chest compression (HFCC) in 10 adult CF patients hospitalized for infectious exacerbations. Patients were randomized to receive alternate treatments of CPT for 30 minutes every 4 hours for 1 day or HFCC for 30 minutes every 4 hours for 1 day over 24 hours; treatments were administered for 4 to 8 days. HFCC data showed significantly greater secretion clearance (p = 0.04).

8. Butler S, O’Neill B. High-frequency chest compression therapy: a case study. Pediatr Pulmonol 1995; 19:56-59.
A retrospective chart review of a patient with advanced cystic fibrosis lung disease showed improved clinical stability and reduced health care utilization after one year of high frequency chest compression (HFCC) therapy.

9. Castile R, Tice J, Flucke R, Filbrun D, Varekojis, McCoy K. Comparison of three sputum clearance methods in in-patients with cystic fibrosis. Pediatr Pulmonol 1998; (suppl 17):329, A443.
Sputum production was measured and compared in 24 in-patients with cystic fibrosis (CF) receiving, in random order, 2 days each of manual chest physiotherapy (mCPT), intrapulmonary percussive ventilation (IPV), and high-frequency chest compression (HFCC) 3 times daily for 30 minutes. Wet and dry sputum weights were similar for all modalities except for wet weights derived from IPV; the difference is attributed to use of an aerosol mouthpiece that stimulates salivation.

10. Clayton Sr RG, Donahue M. ThAIRapy use in 6 to 12 year old children with cystic fibrosis. Pediatr Pulmonol 1998; (suppl 17): 345, A496.
This retrospective review of medical records of 40 children with cystic fibrosis (CF) assessed lung function before and after initiation of high frequency chest compression (HFCC) therapy. After one year of HFCC therapy, declining trends in FEV1 tended to stabilize or improve. HFCC treatment adherence as documented by a device use meter was 68.1% over a 22-month period.

11. D'Angelo S, Craigmyle L, Kanga J. How are patients using alternating pressure vests for chest physiotherapy? Pediatr Pulmonol 1994; (suppl 10):266, A314.
This assessment of high frequency chest compression (HFCC) use by 27 cystic fibrosis patients determined that 58% used their machines one hour or less per week. Most patients’ average daily use was consistent during the first three months of treatment, suggesting that early use habits are a strong predictor of future compliance.

12. Darbee JC, Kanga JF, Ohtake PJ. Physiologic evidence for high-frequency chest wall oscillation and positive expiratory pressure breathing in hospitalized subjects with cystic fibrosis. Physical Therapy 2005; 85:1278-1289.
This study compared physiologic responses to two airway clearance techniques - high frequency chest compression (HFCC) and low positive expiratory pressure (PEP) techniques - in hospitalized subjects with moderate to severe cystic fibrosis (CF) lung disease. Subjects were randomized to either HFCC or PEP on day one and the alternate therapy on day two. Data analysis showed that HFCC and PEP were equally efficacious in improving ventilation distribution, gas mixing, and pulmonary function.

13. Dosman CF, Zuberbuhler PC, Tabak JI, Jones RL. Effects of positive end-expiratory pressure on oscillated volume during high frequency chest compression in children with cystic fibrosis. Can Respir J. 2003; 10:94-98.
In a clinic-based prospective study of 9 children with minimal cystic fibrosis (CF) obstructive airway disease, positive end-expiratory pressure (PEEP) was combined with high-frequency chest compression (HFCC) to evaluate possible additive therapeutic effect. Subjects were placed in a closed - circuit spirometry system and evaluated for changes in end-expiratory lung volumes (EELV) and mean oscillated volume (Vosc) during HFCC alone, and then during HFCC+PEEP. Data showed that adding PEEP during HFCC prevents an HFCC-associated drop in EELV and increases Vosc, suggesting that the addition of PEEP may improve HFCC-induced mucus clearance in children with CF.

14. Grece CA. Effectiveness of high frequency chest compression: a three-year retrospective study. Pediatr Pulmonol 2000; (suppl 20):452.
This three-year retrospective study of 41 cystic fibrosis (CF) patients using either manual chest physiotherapy (CPT) or high-frequency chest compression (HFCC) found a significant improvement in weight gain in the HFCC group (p=0.0001), but no significant differences in hospitalization days or pulmonary function between the two groups.

15. Hansen L, Warwick W. High-frequency chest compression system to aid in clearance of mucus from the lung. Biomed Instrum Technol 1990; 24:289-294.
In a crossover study comparing the volume of mucus cleared using HFCC vs CPT, 5 cystic fibrosis (CF) patients received 30 time and day-matched sessions of each modality administered by a professional therapist. Data showed 1) increased mucus clearance [3.3cc/ HFCC therapy session vs 1.8 cc/ chest physiotherapy (CPT) session] and; 2) Improved lung function. The paper also includes an outcomes report of a 60-month retrospective/prospective study of HFCC use in a 48 year-old man with CF and Pseudomonas aeruginosa in his sputum and a two-year history of worsening pulmonary function. Results showed: 1) after one year of HFCC, the patient’s pulmonary function returned to the level measured five years before initiation of HFCC therapy; 2) a baseline technetium aerosol scan showed absence of ventilation in the upper lobes, but after 8 months of HFCC, a repeat test showed that ventilation was restored in these regions. For every outcome measure, HFCC therapy was shown to be more effective than standard chest physical therapy.

16. Hull KK, Warren RH. ThAIRapy Vest vs. conventional chest physical therapy (CPT): case report. Respir Care 1991; 36:1266-1267.
This case report describes the effects of high frequency chest compression (HFCC) therapy in a 32 year old man hospitalized with end-stage cystic fibrosis (CF) lung disease. Chest physiotherapy was administered for 26 in-patient days with no appreciable mobilization of secretions. CPT was replaced with HFCC for 30 minutes 4x daily, resulting in copious mucus production and improved pulmonary function (FEV1: pre- admission = 0.59; day 27 = 0.70; day 30 = 0.87). After 4 days of HFCC therapy, the patient felt well enough to be discharged.

17. Jones RL, Lester RT, Brown NE. Effects of high-frequency chest compression on respiratory system mechanics in normal subjects and cystic fibrosis patients. Can Respir J 1995; 2:40-46.
In this randomized blinded study investigating short-term effects of high frequency chest compression (HFCC) on several indices of respiratory system mechanics, 10 normal and 10 stable cystic fibrosis (CF) volunteers received HFCC at 10 randomized settings (5, 10, 15, 20, 25 Hz; highest and lowest pressures); effects were measured with balloon-tipped esophageal catheters, spirograms and reverse plesmography. Both normal and CF subjects had similar changes in esophageal pressure (Pes) and end-expiratory lung volume (EELV). EELV decreased approximately 30% from the no-HFCC baseline functional residual capacity (FRC). Differences between normals and CF subjects were dependent upon overall airway function. In CF patients with moderate to severe airway obstruction, HFCC at low pressure and 10-15 Hz minimizes decrease in EELV and maximizes oscillatory flow.

18. Kempainen R, Hazelwood A, Williams C, Dunitz J, Billings J, Milla C. Comparison of airway clearance efficacy of sine and triangular wave high frequency chest wall oscillation in patients with cystic fibrosis. Poster Presentation. North American Cystic Fibrosis Conference, Denver, Co Nov 2-5, 2006.
Fifteen stable CF patients were randomly allocated to receive one 30-minute treatment with each of two high frequency chest compression (HFCC) machines (The Vest ™airway clearance system model 104 [Hill-Rom, St. Paul MN] and The inCourage™ System, aka ICS [RespirTech, St. Paul MN]). A two-day washout interval separated sessions; double-blinding was attempted. Outcomes for: 1) sputum production were non significantly but quantitatively greater with ICS; 2) pulmonary functions were statistically significantly better with ICS for residual lung volumes (suggesting less air-trapping) and forced expiratory volume (FEV) (suggesting greater ability to generate a mucus-clearing cough); 3) differences in mucus rheology (viscosity, elasticity, etc.) were statistically non-significant but numerically better for the ICS system; 4) mucus cough transportability was statistically significantly better for ICS and 5) comfort ratings were equal and positive.

19. Kluft J, Beker L, Castagnino M, Gaiser J, Chaney H, Fink R. A comparison of bronchial drainage treatments in cystic fibrosis. Pediatr Pulmonol 1996; 22:271-274.
This large randomized controlled crossover trial compared the square waveform model 102™ HFCC device [Advanced Respiratory, Inc., St. Paul, MN] with professionally administered chest physiotherapy (CPT) in 29 cystic fibrosis (CF) patients hospitalized with acute pulmonary exacerbations. Subjects were allocated to treatment with HFCC and CPT for 2 days each over a 4-day period. Sputum weight, both wet and dry, was used as a clinical index of mucus clearance efficacy. Results showed significantly greater volume for volume clearance in the HFCC group compared to the CPT group; (wet: p = 0.001; dry: p = 0.01).

20. McColley SA, Harris CV, Qualter N, O'Malley C, Boas SR, Jain M. Predictors of adherence to an airway clearance technique in cystic fibrosis. Pediatr Pulmonol 1999; (suppl 19):332, A582.
This study was designed to assess treatment adherence (TA) with high frequency chest compression (HFCC) therapy and to identify predictors of TA. Participants included twenty-eight cystic fibrosis (CF) patients aged 7-23. Usage times recorded for six months with an hour meter installed in the HFCC machine showed TA to be 43±27%. Factors associated with better TA include 1) greater age; 2) poorer nutrition; 3) worse pulmonary function and; 4) more positive self-assessment of quality of life.

21. McColley SA, Schulz C, Qualter N, Boas SR, Jain M, Goodman DM. Participation in an observational study of airway clearance in cystic fibrosis does not influence patient adherence. Pediatr Pulmonol 1999 ;( suppl 19): 331, A581.
In this corporate-sponsored assessment of treatment adherence (TA) with a high frequency chest compression (HFCC) machine, young ( ages 9-23) cystic fibrosis patients with mild to moderate disease were enrolled in the manufacturer’s outcomes monitoring program. Data showed that HFCC TA was 48±28% for study participants and 49±30% for age-matched patients also receiving the corporate outcomes monitoring but not enrolled in the formal study, suggesting that knowledge of participation in a study does not affect compliance behavior.

22. Milla CE, Hansen LG, Warwick WJ. Different frequencies should be prescribed for different high frequency chest compression machines. Biomed Instrum Technol 2006; 40 (4): 319-324.
HFCC treatment frequencies may be prescribed according to the manufacturers' generic guidelines or may be determined for each individual patient by a "tuning" method that measures, at the mouth, the air volume displacement and the associated airflows produced at each frequency. This paper describes a protocol for finding the best frequencies and pressures for individual patients based upon a sample of 100 consecutive tunings. Data showed that every frequency from 6 and 20 Hz was a best frequency for at least one patient.

23. Milla CE, Hansen LG, Weber A, Warwick WJ. High-frequency chest compression: effect of the third generation compression waveform. Biomed Instrum Technol. 2004; 38:322-328.
In a study comparing the differences in output characteristics between triangle waveform and sine waveform HFCC machines, eight stable CF subjects treated with both modalities yielded a 20% mean increase in volumes of mucus cleared - with a range of improvement up to 41% - with the triangle waveform machine. Authors speculate that 1) the shape of the waveform delivered by HFCC machines is important in maximizing mucus clearance; 2) the triangle waveform may be more effective because peak airflow and maximum lung volumes occur at the same frequencies and; 3) the triangle waveform may be more comfortable as a result of the shorter duration of peak pressure and venting to atmospheric pressure.

24. Oermann CM, Sockrider MM, Giles D, Sontag MK, Accurso FJ, Castile RG. Comparison of high-frequency chest wall oscillation and oscillating positive expiratory pressure in the home management of cystic fibrosis: A pilot study. Pediatr Pulmonol 2001; 32:372-377.
This prospective, randomized, multicenter crossover pilot study evaluates the efficacy and patient satisfaction with high frequency chest compression (HFCC) and oscillating positive expiratory pressure (OPEP) compared to percussion and postural drainage (PDPV) in the home use setting. Twenty-nine CF patients, 9-39 years of age, performed 4 weeks each of HFCC and OPEP following 2-week lead-in/washout periods. Efficacy, safety and compliance differences among therapies were non-significant, but given a choice of therapy, 50% of subjects chose HFCC, 37% OPEP, and 13% PDPV.

25. Oermann CM, Swank PR, Sockrider MM. Validation of an instrument measuring patient satisfaction with Chest Physiotherapy (CPT) techniques in cystic fibrosis. Chest 2000; 118:92-97.
A validated survey instrument to assess patient satisfaction with three airway clearance techniques showed that users of a high frequency chest compression (HFCC) device reported the highest levels of overall satisfaction ( p = < 0.0001) and perceived it as more efficacious ( p = 0.045) when compared to either CPT or the Flutter® valve [post-test Tukey’s Honestly Significant Difference (HSD) method]. Treatment adherence is strongly correlated to severity of illness.

26. Oermann CM, Accurso F, Castile R, Sockrider MM. Evaluation of the safety, efficacy and impact on quality of life of the ThAIRapy Vest and Flutter® compared to conventional chest physical therapy (CPT) in patients with cystic fibrosis. Am J Respir Crit Care Med 1997; 155(suppl 4): A638.
This multicenter, randomized crossover study compared efficacy, safety and patient satisfaction of three popular airway clearance modalities (CPT, HFCC and Flutter). Twenty-four CF patients completing the study received two cycles of a 2-week standard CPT lead-in period followed by 4 weeks of either HFCC or Flutter treatments. Spirometry, lung volumes, NIH and Petty scores, and a satisfaction survey were performed at baseline and after each treatment period. Results showed comparable safety and efficacy for all three modalities, but with NIH scores improved from baseline with HFCC (p= .04); subjects expressed a clear preference for HFCC over both CPT and Flutter.

27. Phillips GE, Pike SE, Jaffe A, Bush A. Comparison of active cycle of breathing and high-frequency oscillation jacket in children with cystic fibrosis. Pediatr Pulmonol. 2004; 37:71-75.
In this study of secretion clearance performance comparing active cycle of breathing techniques (ACBT) with high frequency chest compression ( HFCC) administered by the Hayek Oscillator Cuirass, ten children experiencing CF pulmonary exacerbations received either two supervised sessions using HFCC or two self-treatment ACBT sessions in random order on successive days. Sputum weight and pulmonary function increased significantly with ACBT compared with HFCC, suggesting that ACBT may be more effective for airway clearance during infective CF exacerbations than the Hayek Cuirass.

28. Robinson C, Hernried L. Evaluation of a high frequency chest compression device in cystic fibrosis. Pediatr Pulmonol 1992; ( suppl 8):304, A255.
A three month assessment of the effects of high frequency chest compression (HFCC) on pulmonary function scores showed neither significant improvement nor deterioration; participants reported greater independence and improved ability to self-manage their disease with HFCC.

29. Scherer TA, Barandun J, Martinez E, Wanner A, Rubin EM. Effect of high-frequency oral airway and chest wall oscillation and conventional chest physical therapy on expectoration in patients with stable cystic fibrosis. Chest 1998; 113:1019-1027.
This prospective randomized short-term study compares the effects of oral high-frequency (OHFO) airway oscillation, high frequency chest compression (HFCC), and chest physiotherapy (CPT) in 14 CF patients over age 12 with stable disease. Each subject received two modes of OHFO (1) frequency 8 Hz; inspiratory to expiratory [I:E] ratio 9:1; 2) frequency 14 Hz; I:E ratio 8:1); two modes of HFCC (1) frequency 3 Hz; I:E ratio 4:1; 2) frequency 16 Hz; I:E ratio 1:1, alternating with frequency 1.5 Hz, I:E ratio 6:1), and CPT (clapping, vibration, postural drainage, and encouraged coughing). Subjects had one treatment per study day with 2 or more days between study days. Data were comparable for each modality with respect to weight of expectorated sputum, pulmonary function scores, and oxygen saturation values. All treatments were tolerated but some patients expressed discomfort with oral high-frequency oscillation.

30. Tecklin JS, Clayton RG, Scanlin TF. High frequency chest wall oscillation vs. traditional chest physical therapy in CF-a large, one-year, controlled study. Pediatr Pulmonol 2000; (suppl 20):459.
This well-powered one-year retrospective chart review comparing pulmonary function test (PFT) scores and chest x-ray interpretations in cystic fibrosis patients receiving either high frequency chest compression (HFCC) therapy or chest physiotherapy (CPT) showed comparable PFTs; Brasefield chest x-ray scores were statistically significantly better with HFCC.

31. Varekojis SM, Douce FH, Flucke RL, Filburn DA, Tice JS, McCoy KS, Castile RG. A comparison of the therapeutic effectiveness and preference for postural drainage and percussion, intrapulmonary percussive ventilation, and high-frequency chest wall compression in hospitalized cystic fibrosis patients. Respir Care 2003; 48:24-28.
This comparison study of three airway clearance methods including 1) postural drainage and percussion (PD&P); 2) intrapulmonary percussive ventilation (IPV) and; 3) high-frequency chest wall compression (HFCC), assigned 24 hospitalized CF patients ( aged 12 or older) in random order 2 consecutive days of each therapy, delivered 3 times daily for 30 minutes. Sputum was collected during and for 15 minutes after each treatment and assayed for wet and dry weights. The mean wet sputum weights differed significantly (p = 0.035), with wet sputum weights from IPV significantly greater than with HFCC (p < 0.05). All three modalities are judged comparably effective and equally accepted by patients.

32. Warwick WJ, Hansen LG. The long-term effect of high-frequency chest compression therapy on pulmonary complications of cystic fibrosis. Pediatr Pulmonol 1991; 11:265-271.
This four-year retrospective study of CF patients compared pulmonary function after two years of chest physiotherapy treatment CPT followed by two additional years of high frequency chest compression (HFCC) therapy. After two years of HFCC, 94% of subjects-regardless of disease severity or age- showed either a slowing or reversal of the decline experienced during CPT treatment in terms of percent FEV1; most of the subjects showed meaningful clinical improvement. Results are unprecedented.

33. Warwick WJ, Wielinski CL, Hansen LG. Comparison of expectorated sputum after manual chest physical therapy and high-frequency chest compression. Biomed Instrum Technol. 2004; 38:470-475.
This study compared wet and dry weights of sputum produced by 12 subjects with cystic fibrosis (CF) who received high-frequency chest compression (HFCC) and professionally administered standard chest physical therapy (CPT) in randomized order. The wet and dry weights of the sputum produced as a result of the two techniques were significantly different, with HFCC having greater weight. Regardless of the mode of therapy, the sputum produced by the subjects who regularly received HFCC (6 subjects) had greater water content than did the sputum produced by those subjects who regularly received CPT ( 6 subjects).

34. Wielinski CL, Warwick WJ. Change in pulmonary function over a 30-month period for high-frequency vest users vs. non-users in a cystic fibrosis population. Am J Respir Crit Care Med 1996; 153:A71.
In a 30 month study to assess long-term effects of high frequency chest compression (HFCC) on pulmonary function, test results of 140 cystic fibrosis patients treated with HFCC were compared with 79 who were not exposed to HFCC. Baseline measures were similar for both groups. Over 30 months, decline in % predicted forced expiratory flow at 25-75% (FEF 25-75%) was less for the HFCC group (P = 0.04): HFCC males had significant improvement in forced expiratory volume at one second (FEV1) (p = <.0.05) and FEF 25-75% (P = < 0.01), confirming the long-term benefit of HFCC for preservation of pulmonary function.

Lung Procurement for Transplantation, Use In

Lung transplantation is now a realistic treatment for many patients with end-stage pulmonary diseases. Unfortunately, the demand for transplantable lungs greatly exceeds the supply; many patients die while waiting. Potential donor lungs are frequently rejected for transplantation because their quality is compromised by excess mucus and/or purulent secretions.

1. Babcock W, Menza RL, Riznyk S, Prince P, Kern TJ. Results of a prospective study using high-frequency chest wall oscillation for brain dead organ donors. J Heart Lung Trans, 2002; 21(1): A239.
In this pilot study evaluating the effects HCFF as part of the management protocol for lung donors, the quantity and quality of transplantable lungs increased. One hundred consecutive eligible brain-dead beating heart donor patients were randomized to standard protocol or standard protocol plus HFCC on the basis of equipment availability. Compared with lungs recovered from the non-HFCC group (45 donors), HFCC-treated donor lungs demonstrated improved chest x-ray interpretations (p = 0.026); fewer organisms on gram stain (p = 0.031); a strong trend toward improved P/F ratios (p=0.059); and a lung recovery rate of 40% vs. 24% in the non-HFCC group. Results suggest that HFCC may be a valuable addition to the lung procurement protocol.

2. Braverman JM. Increasing the quantity of lungs for transplantation using high-frequency chest wall oscillation: a proposal. Prog Transplant. 2002; 12:266-74.
The use of chest physiotherapy (CPT) in donor patient management is an established component of most lung procurement protocols. High-frequency chest wall compression (HFCC), which has few of the disadvantages associated with labor-intensive, technique and positioning-dependent CPT, may offer a superior alternative. Extrapolation of data from clinical studies and experience with HFCC in a variety of patient populations suggests that HFCC may have the potential to help increase the quantity and quality donor lungs by controlling the secretion-related complications that make them ineligible for transplantation. Effective management of obstructing pulmonary secretions in donor lungs should reduce the destructive by-products of inflammation and entrapped pathogens and improve ventilation and perfusion.

3. Ganz SS, Levi DM, Nishida S, et al. Improving pulmonary function and lung recovery for transplantation using the Link TM [ high frequency chest compression] during organ donor management. Poster Presentation. Association of Organ Procurement Organizations (AOPO), Chicago IL June 14-18, 2004.
Sixty-one eligible lung donor patients were treated with HFCC in addition to the standard protocol for lung recovery; outcome parameters were compared with 79 historical controls. HFCC-treated donors showed 1) 87% improvement in frequency of successful lung procurement (p = 0.015); [24.7% viable lungs with HFCC vs 12.6% controls] and; 2) maintenance of P/F ratios > 300 mm Hg. (p = 0.04); HFCC appears to be a practical adjunct for increasing rates of lung procurement for transplantation.

Mechanically Ventilated Patients

Mechanical ventilation (MV) requires bypassing the upper airway, thus introducing dry air breathing inadequately compensated by the addition of humidifiers and filters. Decreased humidification injures the mucociliary transport system and causes moisture-related changes in mucus viscosity and elasticity. Concomitant ineffective cough may facilitate retrograde movement of secretions to the lung periphery or aspiration from one lung to the other, leading to ventilator-associated pneumonia (VAP). Prolonged dependence on MV diminishes likelihood of successful weaning.

1. Gomez A, Acker R, Buehler C, Newman V. Successful use of high frequency chest wall oscillation in pediatric post operative spinal fusion. Presentation at the 48th International Respiratory Congress of the American Association for Respiratory Care, AARC 2002 Abstract; OF-O2-156.
A retrospective hospital course chart review is reported for four adolescent spinal fusion patients (idiopathic scoliosis) in a pediatric intensive care unit (PICU) who received high frequency chest compression (HFCC) 3-5 days post- operatively after failing other airway clearance interventions. Indications were atelectasis with or without pleural effusion and with or without evidence of mucus plugging. All patients had either inadequate cough secondary to post operative pain, an artificial airway for ventilatory support and/or neuromuscular disease. HFCC was administered for 20-30 minutes every 2-4 hours. Radiographs after 4 days of HFCC for all patients showed either complete resolution or minimal residual atelectasis.

2. Ndukwu IM, Shapiro S, Nam AJ, Schumm PL. Comparison of high-frequency chest wall oscillation (HFCWO) and manual chest physiotherapy (mCPT) in long-term acute care hospital (LTAC) ventilator-dependent patients. Chest 1999; 116 (4) Suppl: 311S.
This randomized, controlled study of 54 long-term acute care patients who had been ventilator-dependent for a median of 84 days compared chest physiotherapy (CPT) and high frequency chest compression (HFCC) as modalities for secretion management. Subjects were randomized to receive either CPT or HFCC 4 times daily for 15 minutes for 40 days. After 21 days, the HFCC group discharged larger volumes of sputum and, after 40 days, 38 % were weaned from ventilator dependence compared with 15% in the CPT group. No adverse events occurred. Results suggest that HFCC is safe, effective and may promote successful ventilator weaning.

3. Whitman J, Van Beusekom R, Olson S, Worm M, Indihar F. Preliminary evaluation of high-frequency chest compression for secretion clearance in mechanically ventilated patients. Respir Care 1993; 38:1081-1087.
A comparison of the safety and efficacy of percussion and postural drainage (P&PD) and high frequency chest compression (HFCC) in treatment of long-term mechanically ventilated patients showed equivalent safety and efficacy; 80% of therapists believed HFCC reduced their workload.

Neuromotor/Neuromuscular Disorders

Neuromotor and neuromuscular disorders arise from a broad variety of congenital and acquired etiologies; clinical manifestations are equally diverse. In patients with severe disability or advanced disease, respiratory muscle weakness significantly increases risk for pulmonary complications associated with retained airway secretions; respiratory illness is the leading cause of hospitalization and premature death.

1. Castagnino M, Vojtove J, Fink R. Safety of high-frequency chest wall oscillation in patients with respiratory muscle weakness. Chest 1996; 110: S65.
In this controlled short-term evaluation of safety, efficacy and acceptance of high frequency chest compression therapy (HFCC), 8 patients with respiratory muscle weakness (vital capacities of 30 ml/kg or less; Age> 10 years, able to perform PFTs) received HFCC at frequencies of 5, 15, and 20 Hz for five minutes each. Measures of patient comfort, pulmonary function, and other physiological parameters were collected and evaluated as mean percent change from baseline. No clinically relevant changes occurred in physiological values, all patients found HFCC both comfortable and acceptable; no adverse events were noted.

2. Chiappetta A, Beckerman R. High-frequency chest-wall oscillation in spinal muscular atrophy (SMA). RT J Respir Care Pract 1995; 8:112-114.
This six-week study evaluated the substitution of high frequency chest compression (HFCC) to replace chest physiotherapy (CPT) in a ten-year old girl with spinal muscular atrophy. The child had been hospitalized 3x in past year for pneumonia, mucus retention, and pulmonary deterioration. She had received percussion and postural drainage therapy (P&PD) x2 daily from her mother for 4 years. HFCC was administered 2x daily for 30 minutes for 5 minutes at each of 6 frequencies; each 5 minute session was followed by one or two cough maneuvers. After six weeks of HFCC, the patient showed stronger cough function and improvements in FVC, FEV1, MEF and NIF of 25%, 16%, 20%, and 28% respectively.

3. Giarraffa P, Berger KI, Chaikin AA, Axelrod FB, Davey C, Becker B. Assessing efficacy of high-frequency chest wall oscillation in patients with familial dysautonomia. Chest 2005; 128:3377-3381.
This study evaluated daily high-frequency chest compression (HFCC) therapy in15 patients (11-33 years of age) with familial dysautonomia (FD) and clinically evident lung disease. A twelve month retrospective/ prospective medical chart data comparison showed improvements in all measured outcomes including: pneumonias (p = 0.056); hospitalizations (p = 0.0156); antibiotic courses (p = 0.0005); antibiotic days (p = 0.0002); doctor visits (p = 0.0005) and; absenteeism (p = 0.0002).

4. Gomez A, Acker R, Buehler C, Newman V. Successful use of high frequency chest wall oscillation in pediatric post operative spinal fusion. Presentation at the 48th International Respiratory Congress of the American Association for Respiratory Care, AARC 2002 Abstract; OF-O2-156.
A retrospective hospital course chart review is reported for four adolescent spinal fusion patients (idiopathic scoliosis) in a pediatric intensive care unit (PICU) who received high frequency chest compression (HFCC) 3-5 days post- operatively after failing other airway clearance interventions. Indications were atelectasis with or without pleural effusion and with or without evidence of mucus plugging. All patients had either inadequate cough secondary to post operative pain, an artificial airway for ventilatory support and/or neuromuscular disease. HFCC was administered for 20-30 minutes every 2-4 hours. Radiographs after 4 days of HFCC for all patients showed either complete resolution or minimal residual atelectasis.

6. Gomez A, Elisan I, Hardy K. High frequency chest wall oscillation: video documentation of effect on a patient with Duchenne muscular dystrophy and severe scoliosis. Poster presentation at the 46th International Respiratory Congress of the American Association for Respiratory Care, October 7, 2000, Cincinnati, Ohio, USA.
A 16 year-old Duchenne muscular dystrophy patient with severe kyphoscoliosis and deteriorating respiratory health had persistent atelectasis and mucus plugging unresponsive to both manual chest physiotherapy (CPT) and therapeutic bronchoscopy. A subsequent bronchoscopy performed while the patient received high frequency chest compression (HFCC) therapy successfully cleared large volumes of secretions. A follow-up videotaped broncoscopy with HFCC showed healing bronchial mucosa, minimal secretions and significant mobilization for mucus from peripheral lung regions.

7. Overgaard PM, Radford PJ. High frequency chest wall oscillation improves outcomes in children with cerebral palsy. Chest, October 2005.
A retrospective quality assurance review of 13 children with cerebral palsy (CP) using HFCC for airway clearance therapy for at least 6 months (7 for 6+ months; 6 for 1+ years) showed significant aggregate reductions in hospitalizations and emergency room (ER) visits. Chart review for the year prior to HFCC use compared prospectively with 6 or more months of HFCC therapy documented 8 hospitalizations and 5 ER visits vs. 5 hospitalizations and 1 ER visit. Parents reported fewer respiratory illnesses, less antibiotic use, and reduced absenteeism. Treatment adherence (measured by hourly use meter) and parental satisfaction were high.

8. Plioplys AV, Lewis S, Kasnicka I. Pulmonary vest therapy in pediatric long-term care. J Am Med Dir Assoc 2002; 3:318-321.
In this retrospective/prospective study to evaluate the use of high frequency chest compression (HFCC) in institutionalized quadriplegic cerebral palsy (CP) patients with lung disease, 7 subjects (age range 7-28, median age 19) received HFCC for 12 months. All subjects had histories of frequent pulmonary infections, were fed by G-tube and were treated retrospectively with CPT; 5 had tracheostomies, 3 had active seizure disorder. Prospective data was collected and compared with 12 month retrospective data from nursing records maintained daily according to facility protocol. Improvements were shown in all outcome measures after 12 months of HFCC: 1) fewer pneumonias (p = 0.025); 2) fewer hospitalizations (p = 0.16) and; 3) increased effective suctioning interventions (p = 0.008). Unexpectedly, seizures fell from 267 events retrospectively to only 43 during the HFCC year (p = 0.125). HFCC was well tolerated; no complications or side effects were noted.

Stroke

Morbidity and mortality from stroke is associated with pulmonary complications arising from neurologic deficits including hemiparesis, swallowing abnormalities and alterations of consciousness. These impairments interfere with airway protection and effective clearance of pulmonary secretions, resulting in a higher risk for aspiration, atelectasis, pneumonia and hypoxemia.

1. Rhodes DJ, Lemons NV, Coupland DJ, Orr SC, Soto RD, Gomez CR. Simultaneous Application of Vibrating Vest and Cough Assist Device Improve Respiratory Function in Stroke Patient. Univ of Alabama-Birmingham, Birmingham, AL. Presented at the 28th International Stroke Conference, Phoenix, AZ. 2003. [Abstract ID: 100980; Pub Number: P322]
Ten acute stroke patients treated with a combination of HFCC and a mechanical cough-assisting device for at least 3 days showed significant improvement in forced vital capacity (FVC) [p= 0.0001] and minute ventilations (Ve) [ p=0.02] as well as a positive trend in SpO2 [p=0.08] compared to no significant improvements in a control group receiving CPT only.

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