Non-invasive ventilation indications and assessment

Before starting NIV

SectionRecommendationGrade of recommendation


Prior to commencement of NIV patients are to be assessed for:

  • capacity to protect his or her airway
  • level of consciousness (the exception being suitable "do not intubate" unconscious patients with hypercapnic COPD)
  • anticipated level of compliance with interface
  • capacity to manage their respiratory secretions and
  • potential to recover to a quality of life acceptable to the patient.

Failure to meet any one of these criteria renders the patient ineligible for NIV and review of alternate care or escalation of therapy should be undertaken (4, 5).


The evidence review for these recommendations was current to December 2012. Clinicians are advised to check the literature as research may have been published that change these recommendations.

Non-invasive ventilation is increasingly being used as an adjunct to standard medical therapy to treat episodes of ARF in the critical care and specialised respiratory ward setting (5, 6). This technique has also been used as a weaning strategy to facilitate early liberation from invasive ventilation with current evidence suggesting greater benefits in those with a diagnosis of COPD (7). Although NIV does not reduce the need for reintubation in unselected patients who develop post extubation respiratory failure (2, 6) it has been shown to be effective in preventing respiratory failure after extubation in high risk individuals (8). When commenced early, NIV has been shown to significantly decrease: mortality, need for intubation, incidence of ventilator-associated pneumonia (VAP), ICU and hospital length of stay (LOS), duration of endotracheal tube (ETT) and total mechanical ventilation, risk of treatment/weaning failure; as well as improve symptoms of respiratory distress in selected patients (7, 9, 10). Evidence supports the use of bilevel non-invasive ventilation in acute exacerbations of COPD and other disorders characterised by hypoventilation. Continuous positive airway pressure (CPAP) is the other form of NIV, and has been most commonly studied in patients with acute cardiogenic pulmonary oedema (ACPO); While the evidence is mixed regarding the benefit of  NIV in ACPO (11), there is a trend towards a reduction in intubation and mortality (12). However, CPAP is not indicated in the presence of symptomatic CO2 retention(13). Evidence for NIV in ARF secondary to acute exacerbations of asthma is controversial; however, if a clinical trial is to be undertaken it should be limited to an appropriately equipped and staffed setting with close monitoring and low thresholds for intubation (2, 14). At present, there is limited quality evidence to support the use of NIV in disorders such as pneumonia (15) or ARDS (10, 16).

Data from several large registries have shown that over the past decade NIV use has increased at similar relative rates in both COPD and non-COPD diagnostic groups (17). Of significance for clinical practice, when NIV was used for diagnoses with weak supporting evidence, it was more likely to fail (17). Furthermore, when patients required intubation after NIV failure they were more likely to die than patients who were intubated directly without a preceding trial of NIV (17). This highlights the importance of appropriate patient selection when considering NIV.

Despite the benefits to morbidity and mortality classification of disease is not the only determinant for or against the use of NIV; patients must also be assessed for clinical inclusion/exclusion signs and symptoms.

Clinical indications for non-invasive ventilation

  • Severe (acute) exacerbation of COPD (pH<7.35 and relative hypercarbia) (18, 19).
  • ACPO and ARF in the absence of shock or acute coronary syndrome requiring acute coronary revascularization (13).
  • Immunosuppressed patients with acute respiratory failure (20).
  • High risk recurrent acute respiratory failure after planned extubation (not indicated post extubation for low risk patients) (2).
  • Weaning from mechanical ventilation particularly in patients with a background of COPD (7).
  • Acute respiratory failure following lung resection surgery or post abdominal surgery (2, 21).
  • Asthma (14).
  • Acute respiratory failure in selected ‘not for intubation’ patients (22).
  • Acute deterioration of disorders associated with sleep hypoventilation such as neuromuscular and chest wall restrictive disorders and obesity hypoventilation syndrome (15, 23, 24).
  • Palliation for symptom relief in combination with opioids and benzodiazepines to treat breathlessness. A medical team decision will be made when NIV is deemed no longer beneficial to the patient’s management (1).

Contraindications for non-invasive positive pressure support ventilation

  • Heliox therapy in combination with NIV for severe exacerbation of COPD (2).
  • Life-threatening hypoxemia (PaO2 <60mmHg on iO2 100%) (1).
  • CPAP in acute lung injury (ALI) (2).
  • Respiratory arrest (1).
  • Untreated pneumothorax (18) Life-threatening dysrhythmias (1).
  • Inability to protect own airway (1, 10, 25).
  • Copious, unmanageable respiratory secretions (1, 10, 25)
    Facial burns/trauma/recent facial or upper airway surgery (1).

Ongoing Assessment

SectionRecommendationGrade of recommendation


All patients receiving NIV are to have a documented plan of care. This plan is to be developed on commencement of NIV, reviewed on a regular basis (at least every 24 hours and with a change in the patient’s condition) and updated as required. Where available, the care plan is to be developed by a critical care or respiratory Medical Officer or designated clinically qualified respiratory proxy.



All patients receiving NIV are to have a formal assessment and documentation of full body skin integrity at least daily. This includes the skin under the interface i.e. nose, face and neck.


The evidence review for these recommendations was current to December 2012. Clinicians are advised to check the literature as research may have been published that change these recommendations.

There have been no definitive studies on what observations should be taken on a patient receiving NIV or the optimum frequency of these observations. The frequency and type of observations in this guideline have been based on recommendations from the British Thoracic Society Consensus guideline (1). This suggests continuous observation of respiratory rate, heart rate, level of consciousness, patient comfort, patient pain score, chest wall movement, ventilator synchrony and accessory muscle use for the first 15 minutes after initiation of treatment, followed by regular observations at 15-minute intervals for the first hour then every 30 minutes in the 1-4 hour period, then hourly for the duration of the treatment.

Regular assessment of gas exchange and acid-base status is required to evaluate the patient’s response to treatment. Research has identified that where patients are not shocked the correlation between arterial and venous pCO2 was poor and it is not clinically acceptable to substitute arterial for venous results (26). Therefore while venous blood gases (VBGs) are usually easier, less painful and more convenient, it is recommended that ABGs be used to measure biochemistry for patients on NIV.

Observations required to inform an integrative management plan lists the parameters to be observed, evaluated and documented to formulate an integrative management plan.

Observations required to inform an integrative management plan

Baseline observations






Evaluate patient level of breathlessness –

Borg Scale (see Modified Borg Scale below)


Heart rate

Blood pressure

Cardiac monitoring


Level of consciousness e.g. AVPU

Patient comfort

Pain score
NB Consider other systems as pertains to patient co-morbidities

Ongoing observations

Repeat ABGs
  • After 1 hour of therapy and 1 hour after every subsequent change in settings
  • After 4 hours or earlier in patients who are not improving clinically
Frequent clinical monitoring of acutely ill patients
  • Every 15 minutes in the first hour
  • Every 30 minutes in the 1-4 hour period
  • Then hourly
Observations should include
  • RR, continuous pulse oximetry, HR, BP, AVPU,
  • Pain score
  • Patient comfort, including interface skin integrity
  • Chest wall movement, ventilator synchrony, accessory muscle use (1)

Modified Borg Scale




Nothing at all


Extremely slight (just noticeable)


Very slight






Somewhat severe






Very severe




Extremely severe (almost maximal)



Borg RPE scale © Gunnar Borg, 1970, 1985, 1994, 1998.

Grading of recommendations

Grade of recommendation



Body of evidence can be trusted to guide evidence


Body of evidence can be trusted to guide practice in most situations


Body of evidence provides some support for recommendation/s but care should be taken in its application


Body of evidence is weak and recommendation must be applied with caution


Consensus was set as a median of ≥ 7

Grades A–D are based on NHMRC grades (14)


  1. Roberts CM, Brown JL, Reinhardt AK, Kaul S, Scales K, Mikelsons C, et al. Non-invasive ventilation in chronic obstructive pulmonary disease: management of acute type 2 respiratory failure. Clin Med. 2008;8(5):517-21.
  2. Keenan SP, Sinuff T, Burns KE, Muscedere J, Kutsogiannis J, Mehta S, et al. Clinical practice guidelines for the use of noninvasive positive-pressure ventilation and noninvasive continuous positive airway pressure in the acute care setting. Cmaj. 2011;183(3):14.
  3. Arroliga AC. Noninvasive positive pressure ventilation in acute respiratory failure: does it improve outcomes? Cleveland Clinic journal of medicine. 2001;68(8):677-80.
  4. Kaul S. Non-invasive ventilation. AIRWAYS JOURNAL. 2005;3(3):155.
  5. Chandra D, Stamm JA, Taylor B, Ramos RM, Satterwhite L, Krishnan JA, et al. Outcomes of noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease in the United States, 1998–2008. American journal of respiratory and critical care medicine. 2012;185(2):152-9.
  6. Esteban A, Ferguson ND, Meade MO, Frutos-Vivar F, Apezteguia C, Brochard L, et al. Evolution of mechanical ventilation in response to clinical research. American journal of respiratory and critical care medicine. 2008;177(2):170-7.
  7. Burns KE, Adhikari NK, Keenan SP, Meade MO. Noninvasive positive pressure ventilation as a weaning strategy for intubated adults with respiratory failure. Cochrane Database Syst Rev. 2010;4(8).
  8. Ferrer M, Sellares J, Valencia M, Carrillo A, Gonzalez G, Badia JR, et al. Non-invasive ventilation after extubation in hypercapnic patients with chronic respiratory disorders: randomised controlled trial. Lancet. 2009;374(9695):1082-8.
  9. McCurdy B. Noninvasive Positive Pressure Ventilation for Acute Respiratory Failure Patients With Chronic Obstructive Pulmonary Disease (COPD): An Evidence-Based Analysis. Ontario Health Technology Assessment Series. 2012;12(8):1.
  10. Nava S, Hill N. Non-invasive ventilation in acute respiratory failure. Lancet. 2009;374(9685):250-9.
  11. Gray A, Goodacre S, Newby D. Noninvasive Ventilation in Acute Cardiogenic Pulmonary Edema Reply. MASSACHUSETTS MEDICAL SOC WALTHAM WOODS CENTER, 860 WINTER ST,, WALTHAM, MA 02451-1413 USA; 2008. p. 2069-.
  12. Weng C-L, Zhao Y-T, Liu Q-H, Fu C-J, Sun F, Ma Y-L, et al. Meta-analysis: Noninvasive ventilation in acute cardiogenic pulmonary edema. Annals of internal medicine. 2010;152(9):590-600.
  13. Moritz F, Brousse B, Gellée B, Chajara A, L'HER E, Hellot M-F, et al. Continuous positive airway pressure versus bilevel noninvasive ventilation in acute cardiogenic pulmonary edema: a randomized multicenter trial. Annals of emergency medicine. 2007;50(6):666-75.
  14. Nowak R, Corbridge T, Brenner B. Noninvasive ventilation. J Emerg Med. 2009;37(2 Suppl):S18-22.
  15. Carrillo A, Ferrer M, Gonzalez-Diaz G, Lopez-Martinez A, Llamas N, Alcazar M, et al. Noninvasive ventilation in acute hypercapnic respiratory failure caused by obesity hypoventilation syndrome and chronic obstructive pulmonary disease. American journal of respiratory and critical care medicine. 2012;186(12):1279-85.
  16. Agarwal R, Reddy C, Aggarwal AN, Gupta D. Is there a role for noninvasive ventilation in acute respiratory distress syndrome? A meta-analysis. Respiratory medicine. 2006;100(12):2235-8.
  17. Walkey AJ, Wiener RS. Use of Noninvasive Ventilation in Patients with Acute Respiratory Failure, 2000–2009: A Population-Based Study. Annals of the American Thoracic Society. 2013;10(1):10-7.
  18. Plant P, Owen J, Elliott M. Early use of non-invasive ventilation for acute exacerbations of chronic obstructive pulmonary disease on general respiratory wards: a multicentre randomised controlled trial. The Lancet. 2000;355(9219):1931-5.
  19. Ram FS, Picot J, Lightowler J, Wedzicha JA. Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease. Cochrane Database Syst Rev. 2004;3.
  20. Hilbert G, Gruson D, Vargas F, Valentino R, Gbikpi-Benissan G, Dupon M, et al. Noninvasive ventilation in immunosuppressed patients with pulmonary infiltrates, fever, and acute respiratory failure. New England Journal of Medicine. 2001;344(7):481-7.
  21. Chiumello D, Chevallard G, Gregoretti C. Non-invasive ventilation in postoperative patients: a systematic review. Intensive Care Med. 2011;37(6):918-29.
  22. Schettino G, Altobelli N, Kacmarek RM. Noninvasive positive pressure ventilation reverses acute respiratory failure in select" do-not-intubate" patients. Critical care medicine. 2005;33(9):1976-82.
  23. Girault C, Bubenheim M, Abroug F, Diehl JL, Elatrous S, Beuret P, et al. Noninvasive Ventilation and Weaning in Patients with Chronic Hypercapnic Respiratory Failure A Randomized Multicenter Trial. American journal of respiratory and critical care medicine. 2011;184(6):672-9.
  24. Nava S, Navalesi P, Gregoretti C. Interfaces and humidification for noninvasive mechanical ventilation. Respir Care. 2009;54(1):71-84.
  25. Masip J. Non-invasive ventilation. Heart Fail Rev. 2007;12(2):119-24.
  26. Kelly AM. Review article: Can venous blood gas analysis replace arterial in emergency medical care. Emergency Medicine Australasia. 2010;22(6):493-8.


The information on this page is general in nature and cannot reflect individual patient variation. It reflects Australian intensive care practice, which may differ from that in other countries. It is intended as a supplement to the more specific information provided by the doctors and nurses caring for your loved one. ICNSW attests to the accuracy of the information contained here but takes no responsibility for how it may apply to an individual patient. Please refer to the full disclaimer.