Non-invasive Negative Pressure Ventilation: Body Ventilators and Poncho Wrap

Number: 0298

Table Of Contents

Applicable CPT / HCPCS / ICD-10 Codes


Scope of Policy

This Clinical Policy Bulletin addresses non-invasive negative pressure ventilation: Body ventilators and poncho wrap.

  1. Medical Necessity

    1. Aetna considers non-invasive negative pressure ventilation medically necessary durable medical equipment (DME) for members with stable or slowly progressive respiratory failure due to neuromuscular diseases, chest wall deformity, or central hypoventilation syndromes (see background section for selection criteria).
    2. Aetna considers a second invasive or non-invasive ventilator medically necessary if it is required to serve a different purpose as determined by the member’s medical needs.  Examples (not all-inclusive) of situations in which multiple ventilators may be considered medically necessary are:

      1. An individual requires one type of ventilator (e.g., a negative pressure ventilator with a chest shell) for part of the day and needs a different type of ventilator (e.g., positive pressure ventilator with a nasal mask) during the rest of the day.
      2. An individual who is confined to a wheelchair requires a ventilator mounted on the wheelchair for use during the day and needs another ventilator of the same type for use while in bed.  Without both pieces of equipment, the individual may be prone to certain medical complications, may not be able to achieve certain appropriate medical outcomes, or may not be able to use the medical equipment effectively.

      Note: Non-invasive negative pressure ventilation may be given to members with respiratory failure with the use of devices that apply intermittent negative extra-thoracic pressure and augment tidal volume.  These include body ventilators and the poncho wrap.

  2. Experimental and Investigational

    Aetna considers non-invasive negative pressure ventilation experimental and investigational for all other indications (e.g., acute hypoxemic respiratory failure) because its effectiveness for indications other than the ones listed above has not been established.

  3. Policy Limitations and Exclusions

    Note: Electrical generators do not meet Aetna’s definition of DME because they are not primarily medical in nature.


CPT Codes / HCPCS Codes / ICD-10 Codes

Code Code Description

Information in the [brackets] below has been added for clarification purposes.   Codes requiring a 7th character are represented by "+":

CPT codes covered if selection criteria are met:

94662 Continuous negative pressure ventilation (CNP), initiation and management

Other CPT codes related to the CPB:

82800 Gases, blood, pH only
82803 Gases, blood, any combination of pH, pCO2, pO2, CO2, HCO3 (including calculated O2 saturation);
82805     with O2 saturation, by direct measurement, except pulse oximetry
82810 Gases, blood O2 saturation only, by direct measurement, except pulse oximetry
82820 Hemoglobin-oxygen affinity (pO2 for 50 % hemoglobin saturation with oxygen)

HCPCS codes covered if selection criteria are met:

E0457 Chest shell (cuirass)
E0459 Chest wrap

ICD-10 codes covered if selection criteria are met:

J96.10 - J96.12 Chronic respiratory failure

ICD-10 codes not covered if selection criteria are met:

J96.00 - J96.02 Acute respiratory failure [acute hypoxemic respiratory failure]


The term non-invasive ventilation refers to the delivery of ventilatory support without endotracheal intubation or tracheostomy.  Traditionally, non-invasive ventilation has been given with the use of devices that apply intermittent negative extra-thoracic pressure (non-invasive negative pressure ventilation).  More recently the use of non-invasive ventilation has greatly expanded with the advent of positive pressure ventilation that is delivered through a nasal or face mask (non-invasive positive pressure ventilation).

Tank-type negative-pressure ventilators, such as the Emerson iron lung or Drinker respirator, were the mainstay of ventilatory support during the polio epidemics in the 1950's.  Although the tank ventilator is reliable, it is bulky (3 meters long) and heavy (300 kg), virtually precluding portability.  A more portable fiberglass tank ventilator is available (Portalung, Nellcor Puritan Bennett, St. Louis, MO), but it weighs approximately 50 kg and requires 2 persons to move.  Subsequently, less bulky, more portable negative-pressure ventilators were developed.  Today, the most commonly used negative-pressure ventilator is the poncho wrap (or jacket) ventilator (Numowrap, Respironics, Inc., Pittsburgh, PA), which consists of an impermeable nylon jacket suspended by a rigid chest piece that fits over the chest and abdomen.  The cuirass (or tortoise shell) ventilator is another negative-pressure device, which consists of a rigid plastic or metal dome over the chest and abdomen.  The chest and wrap ventilators are lightweight, but both must be connected to negative-pressure generators, which weigh 15 to 30 kg, such as the Maxi-vent (Nellcor Puritan Bennett, St. Louis, MO), Emerson NPV (J.J. Emerson, Inc., Cambridge, MA), or NEV-100 (Respironics, Inc., Pittsburgh, PA).

Negative-pressure ventilators work by intermittently applying a sub-atmospheric pressure to the chest wall and abdomen; this increases transpulmonary pressure and causes atmospheric pressure at the mouth to inflate the lungs.  Expiration occurs passively by elastic recoil of the lung and chest wall as pressure within the device rises to atmospheric levels.  Several uncontrolled studies reported benefits of intermittent negative pressure ventilation in patients with chronic respiratory failure due to chest wall deformity, neuromuscular diseases, and central hypoventilation.  In patients with stable, severe chronic obstructive pulmonary disease (COPD), however, a large randomized controlled trial found that negative pressure ventilation had no benefit (Shapiro, 1992).  The non-invasive use of positive-pressure ventilators has now superseded negative-pressure treatment for COPD.

Regarding use of noninvasive negative pressure ventilation in COPD, the Global Initiative for Chronic Obstructive Lung Disease (GOLD, 2010) concluded that negative pressure ventilation is not indicated for the chronic management of stage IV, very severe COPD patients, with or without CO2 retention. The GOLD guidelines state that negative pressure ventilation has been demonstrated to have no effect on shortness of breath, exercise tolerance, arterial blood gases, respiratory muscle strength, or quality of life in COPD patients with chronic respiratory failure.

In recent years, negative-pressure ventilation has been used infrequently for the management of patients with acute respiratory failure.  In a review of the literature on non-invasive ventilation, Hillberg and Johnson (1997) noted that the role of negative pressure ventilation in the management of acute respiratory failure is unclear.  Studies of the use of the body ventilator or poncho wrap for patients with acute respiratory failure and COPD, neuromuscular disease, or chest wall deformity suggest some benefit from these devices, but the studies have not been prospective and controlled.

Hillberg and Johnson (1997) also noted that negative pressure ventilation has not been widely used, because of poor acceptance by patients, inadequate effectiveness for many patients, the awkward size of the devices, and the development of upper airway obstruction in some patients.  Candidates for non-invasive negative-pressure ventilation with chronic respiratory failure should have at least mild to moderate daytime CO2 retention (usually an indication of more severe nocturnal CO2 retention).  Candidates with mild CO2 retention should also have symptoms attributable to hypoventilation and associated poor sleep quality such as morning headache, daytime hypersomnolence, and energy loss.  In the absence of evidence of daytime CO2 retention, there should be direct evidence of nocturnal hypoventilation and oxygen desaturation.  A recent consensus conference concluded that a PaCO2 greater than 45 mm Hg or abnormal nocturnal oxygen saturation was a sufficient indication for non-invasive ventilation (Robert, 1993; NAMDRC, 1999).  Clinically significant hypoxemia during sleep has been defined as oxyhemoglobin saturation of less than 88 % for at least 5 minutes (NAMDRC, 1999).

Patients with stable or slowly progressive neuromuscular diseases, central hypoventilation, or chest wall deformities are the best candidates for non-invasive negative-pressure ventilation.  On the other hand, patients with rapidly progressive neuromuscular processes like Guillian-Barre syndrome are poor candidates.

Appropriate candidates for non-invasive ventilation should have adequate upper airway function and no excessive airway secretions.  Non-invasive ventilation is not indicated in diseases that affect the upper airways, such as amyotrophic lateral sclerosis.  Reversible underlying disorders that may be contributing to the patient's symptoms (e.g., hypothyroidism, congestive heart failure, etc.) should be adequately treated.  In general, non-invasive ventilation should not be used in patients who are unable to cooperate or who have impaired consciousness, problems with retained secretions, or hemodynamic instability.

Shah and colleagues (2013) stated that acute hypoxemic respiratory failure (AHRF) is an important cause of mortality and morbidity in children.  Positive pressure ventilation is currently the standard care; however, it does have complications.  Continuous negative extrathoracic pressure (CNEP) ventilation or continuous positive airway pressure (CPAP) ventilation delivered via non-invasive approaches (Ni-CPAP) have shown certain beneficial effects in animal and uncontrolled human studies.  In a Cochrane review, these researchers evaluated the effectiveness of CNEP or Ni-CPAP compared to conventional ventilation in children (at least 1 month old and less than 18 years of age) with AHRF due to non-cardiogenic causes for improving the mortality or morbidity associated with AHRF.  These investigators searched CENTRAL 2013, Issue 6, MEDLINE (January 1966 to week 3 of June 2013), EMBASE (1980 to July 2013) and CINAHL (1982 to July 2013).  Randomized or quasi-randomized clinical trials of CNEP or Ni-CPAP versus standard therapy (including positive pressure ventilation) involving children (from 1 month old to less than 18 years at time of randomization) who met the criteria for diagnosis of AHRF with at least one of the outcomes reported.  These researchers assessed risk of bias of the included studies using allocation concealment, blinding of intervention, completeness of follow-up and blinding of outcome measurements.  They abstracted data on relevant outcomes and estimated the effect size by calculating risk ratio (RR) and risk difference (RD) with 95 % confidence intervals (CI).  These investigators identified 2 eligible studies: 1 of CPAP and 1 of CNEP (published as an abstract).  Both were un-blinded studies with mainly unclear risk of bias due to lack of adequate information to assess this.  The CPAP study enrolled 37 children to oxygen mask and CPAP and reported improvement in respiratory rate and oxygen saturation in both arms after 30 mins of application.  The CNEP study was published as an abstract and included 33 infants with bronchiolitis.  In the CNEP study there was a reduction in the fraction of inspired oxygen (FiO2) (less than 30 % within 1 hour of initiation of therapy) in 4 participants in the CNEP group compared to none in the control group (RR 10.7, 95 % CI: 0.6 to 183.9).  One infant required CPAP and mechanical ventilation in the control group while all infants in the CNEP group were managed without intubation (RR for both outcomes 0.40, 95 % CI: 0.02 to 9.06).  None of the trials reported on mortality.  No adverse events were reported in ether of the included trials.  The authors concluded that there is a lack of well-designed, controlled trials of non-invasive modes of respiratory support in children with AHRF.  Moreover, they stated that studies assessing the outcomes mortality, avoidance of intubation and its associated complications, hospital stay and patient comfort are needed.

Chao and Nassef (2021) noted that pulmonary rehabilitation combined with negative pressure ventilation (NPV) demonstrated benefits in patients with COPD; however, the effect of NPV remains unknown.  In a pilot study, these researchers examined the short-term response of the hemodynamic outcome of NPV in patients with COPD undergoing pulmonary rehabilitation program by electrical cardiometry.  This was a retrospective, observational study of COPD patients who had been treated in a pulmonary rehabilitation unit with NPV between January 2018 and December 2019 that were enrolled to analyze the hemodynamic outcomes.  A total of 30 patients with COPD who were undergoing a pulmonary rehabilitation program and were regularly receiving NPV were enrolled.  Cardiac output (p < 0.001) and heart rate (p < 0.001) showed a significant decrease after NPV.  Stroke volume (SV) did not demonstrate significant change (p = 0.15).  There was a significant decrease in thoracic fluid content (p = 0.016) and a significant increase in SV variation (p = 0.038) systemic vascular resistance (p < 0.001) and left ventricular ejection time (p < 0.001).  Other hemodynamic parameters were all comparable before and after NPV.  The authors concluded that NPV demonstrated an impact on hemodynamics in patients with COPD undergoing pulmonary rehabilitation.  Electrical cardiometry is a feasible method of determining the hemodynamic effects of NPV.  Thoracic fluid content significantly decreased immediately after the NPV.  Moreover, these researchers stated that further investigation on changes in hemodynamics of patients with COPD who received NPV is needed to clarify further details.

The authors stated that this study had several drawbacks.  To their best knowledge, this was the 1st study to examine the effects of NPV on the hemodynamics of patients with COPD in a pulmonary rehabilitation program; however, in contrast to their expectation, hemodynamics was found to be affected by the sitting position.  Co-morbidities (e.g., cardiovascular diseases) were common among patients with COPD; therefore, a potential bias in this report was that these investigators were unaware of whether patients with COPD and cardiovascular disease took medication before NPV treatment. In the present study, NPV was provided at a mandatory rate with zero end‐expiratory pressure, whereas most related studies have used continuous external NPV.  These researchers did not carry out the pulmonary function test routinely before and after NPV.  Thus, these investigators have not presented lung function after NPV in this report.


Selection Criteria for Non-invasive Negative Pressure Ventilation

Aetna considers non-invasive negative pressure ventilation medically necessary DME for members who meet the following criteria:

  1. Member has been diagnosed with any of the following conditions: 

    1. Central hypoventilation (i.e., apnea not due to airway obstruction); or
    2. Chest wall deformity (e.g., post-thoracoplasty for tuberculosis, etc.); or 
    3. Slowly progressive neuromuscular diseases (e.g., muscular dystrophies, poliomyelitis, multiple sclerosis, spinal cord diseases, diaphragmatic paralysis, etc.); and
  2. Member has chronic stable or slowly progressive respiratory failure that meets any of the following criteria:  

    1. Significant CO2 retention (PaCO2 greater than 50 mm Hg); or  
    2. Mild CO2 retention (PaCO2 greater than 45 mm Hg) with any of the following symptoms:  

      1. Cognitive dysfunction, or
      2. Daytime hypersomnolence, or
      3. Morning headache, or  
    3. Documented nocturnal hypoventilation or oxygen desaturation (with oxyhemoglobin saturation less than 88 % for at least 5 minutes).


The above policy is based on the following references:

  1. Annane D, Orlikowski D, Chevret S, et al. Nocturnal mechanical ventilation for chronic hypoventilation in patients with neuromuscular and chest wall disorders. Cochrane Database Syst Rev. 2007;(4):CD001941.
  2. Bonekat HW. Noninvasive ventilation in neuromuscular disease. Crit Care Clin. 1998;14(4):775-797.
  3. Chao K-Y, Nassef Y. A pilot study of short-term hemodynamic effects of negative pressure ventilation in chronic obstructive pulmonary disease assessed using electrical cardiometry. Ann Noninvasive Electrocardiol. 2021;26(5):e12843.
  4. Chen ML, Keens TG. Congenital central hypoventilation syndrome: Not just another rare disorder. Paediatr Respir Rev. 2004;5(3):182-189.
  5. Corrado A, Gorini M. Long-term negative pressure ventilation. Respir Care Clin N Am. 2002;8(4):545-557, v-vi.
  6. Corrado A, Gorini M. Negative-pressure ventilation: Is there still a role? Eur Respir J. 2002;20(1):187-197.
  7. Curran FJ. Night ventilation by body respirators for patients in chronic respiratory failure due to late stage Duchenne muscular dystrophy. Arch Phys Med Rehab. 1981;62:270-274.
  8. Ferguson G. Noninvasive ventilation. National Jewish Medical and Research Center Medical/Scientific Update. 1993;11(3):1-3.
  9. Garay SM, Turino GM, Goldring RM. Sustained reversal of chronic hypercapnia in patients with alveolar hypoventilation syndromes: Long-term maintenance with noninvasive nocturnal mechanical ventilation. Am J Med. 1981;70:269-274.
  10. Gilmartin ME. Body ventilators. Equipment and techniques. Respir Care Clin N Am. 1996;2(2):195-222.
  11. Global Initiative for Chronic Obstructive Lung Disease (GOLD). Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. Bethesda, MD: Global Initiative for Chronic Obstructive Lung Disease (GOLD); 2010.
  12. Hill NS, Kramer NR. Types of noninvasive nocturnal ventilatory support in neuromuscular and chest wall disease. UpToDate [online serial]. Waltham, MA: UpToDate; reviewed January 2014.
  13. Hill NS. Noninvasive mechanical ventilation. In: Pulmonary and Critical Care Medicine. 1998 ed. RC Bone, DR Dantzker, RB George, et al., eds. St. Louis, MO: Mosby-Year Book, Inc.; 1998: R41-1 - R41-22.
  14. Hill NS. Use of negative pressure ventilation, rocking beds, and pneumobelts. Respir Care. 1994;39(5):532-549.
  15. Hillberg RE, Johnson DC. Current concepts: Noninvasive ventilation. N Engl J Med. 1997;337(24):1746-1752.
  16. Huang HY, Chou PC, Joa WC, et al. Pulmonary rehabilitation coupled with negative pressure ventilation decreases decline in lung function, hospitalizations, and medical cost in COPD: A 5-year study. Medicine (Baltimore). 2016;95(41):e5119.
  17. Hull J, Aniapravan R, Chan E, et al. British Thoracic Society guideline for respiratory management of children with neuromuscular weakness. Thorax 2012;67(Suppl 1):i1-i40.
  18. Imitazione P, Annunziata A, Lanza M, Fiorentino G. Combined high flow nasal cannula and negative pressure ventilation as a novel respiratory approach in a patient with acute respiratory failure and limb-girdle muscular dystrophy. Acta Myol. 2021;40(2):101-104.
  19. National Association for Medical Direction of Respiratory Care (NAMDRC). Clinical indications for noninvasive positive pressure ventilation in chronic respiratory failure due to restrictive lung disease, COPD, and nocturnal hypoventilation -- A consensus conference report. Chest. 1999;116(2):521-534.
  20. Ottonello G, Ferrari I, Pirroddi IM, et al. Home mechanical ventilation in children: Retrospective survey of a pediatric population. Pediatr Int. 2007;49(6):801-805.
  21. Owens MW, Wissing DR, Milligan SA, et al. Respiratory care modalities. In: Pulmonary and Critical Care Medicine. 1998 Ed. RC Bone, DR Dantzker, RB George, et al., eds. St. Louis, MO: Mosby-Yearbook, Inc.; 1998: D5-1 - D5-20.
  22. Palmetto Government Benefits Administrators (GBA), Durable Medical Equipment Regional Carrier. Backup equipment. DMERC Medicare Advisory. Issue 42. Columbia, SC: Palmetto GBA; Autumn 2002:84-85.
  23. Robert D, Willig TN, Paulus J, et al. Long-term nasal ventilation in neuromuscular disorders: Report of a consensus conference. Eur Respir J. 1993;6:599-606.
  24. Shah PS, Ohlsson A, Shah JP. Continuous negative extrathoracic pressure or continuous positive airway pressure for acute hypoxemic respiratory failure in children. Cochrane Database Syst Rev. 2008;(1):CD003699.
  25. Shah PS, Ohlsson A, Shah JP. Continuous negative extrathoracic pressure or continuous positive airway pressure compared to conventional ventilation for acute hypoxaemic respiratory failure in children. Cochrane Database Syst Rev. 2013;11:CD003699.
  26. Shapiro SH, Ernst P, Gray-Donald K, et al. Effect of negative pressure ventilation in severe chronic obstructive pulmonary disease. Lancet. 1992;340:1425-1429.
  27. Shneerson JM, Simonds AK. Noninvasive ventilation for chest wall and neuromuscular disorders. Eur Respir J. 2002;20(2):480-487.