The role of NIV in COPD is to decrease work of breathing and improve respiratory mechanics through effects on several pathophysiologic abnormalities present in severe COPD (Table 1).
When should NIV be given to COPD patients?
Patients recovering from acute respiratory failure associated with an exacerbation of COPD should be evaluated at 2–4 weeks after resolution of respiratory acidosis, and those with persistent hypercapnia should be given home NIV.1 Stable COPD patients with chronic hypercapnic respiratory failure also benefit from home NIV.3
How does NIV work?
How does NIV work? Non-invasive positive pressure ventilation delivers intermittent positive airway pressure (PAP), which gives the patient ventilatory support using a face or nasal mask. This is achieved through a pressure-cycled machine known as BiPAP.
What is the pathophysiology of acute COPD with Niv?
COPD with: Intolerance of supplementary oxygen (because of CO 2 retention) with symptomatic sleep disturbance All patients who have been treated with NIV for acute hypercapnic respiratory failure should undergo spirometric testing and arterial blood gas analysis while breathing air prior to discharge.
How effective is noninvasive ventilation (NIV) for COPD?
A number of studies have identified the effectiveness of NIV in patients with an acute exacerbation of COPD, complicated by type 2 RF (Quon et al, 2008; Royal College of Physicians et al, 2008; Lightowler et al, 2003; Plant et al 2001; 2000); this has been one of the major technological advances in respiratory management in the last decade.
Why is NIV used for COPD?
NIV is used in nearly one third of COPD patients considered to have a poor life expectancy (71). Its use in this setting has a weak evidence base but used judiciously can contribute to symptom relief without adding to the care burden. NIV can relieve breathlessness by unloading the respiratory muscles.
Does NIV help with COPD?
Noninvasive ventilation (NIV) has been shown to be an effective treatment for ventilatory failure resulting from acute exacerbations of chronic obstructive pulmonary disease (COPD) 1–16. It has been used in a variety of settings and in exacerbations of differing degrees of severity.
How does NIV reduce CO2?
This is achieved through a pressure-cycled machine known as BiPAP. The higher level of pressure assists ventilation during inspiration (IPAP) by lowering CO2 levels, while the lower level maintains airway patency during expiration (EPAP), thereby increasing oxygen levels.
How does NIV improve gas exchange?
In conclusion, this study suggests improved gas-exchange and reduced sleepiness in symptomatic hypercapnic COPD patients initiated on NIV. It supports the hypothesis that improvements are brought about by optimization of pulmonary mechanics with reduced gas-trapping and increased ventilatory sensitivity to CO2.
Which mode of ventilation is most common for COPD?
Mechanical ventilation is a lifesaving therapy in patients who have acute respiratory failure due to chronic obstructive pulmonary disease (COPD).
How does NIV ventilation work?
NIV works by creating a positive airway pressure - the pressure outside the lungs being greater than the pressure inside of the lungs. This causes air to be forced into the lungs (down the pressure gradient), lessening the respiratory effort and reducing the work of breathing.
How is CO2 retention treated in COPD?
Options include:Ventilation. There are two types of ventilation used for hypercapnia: ... Medication. Certain medications can assist breathing, such as:Oxygen therapy. People who undergo oxygen therapy regularly use a device to deliver oxygen to the lungs. ... Lifestyle changes. ... Surgery.
How do you wash out CO2 in a ventilated patient?
In a mechanically ventilated patient, the CO2 content of the blood can be modified by changing the tidal volume or the respiratory rate.
What is pressure support on NIV?
In NIV, pressure support and CPAP are often used in combination as bi-level pressure support. Ventilation is produced by the inspiratory positive airway pressure (IPAP), while the expiratory positive airway pressure (EPAP) recruits underventilated lung and offsets intrinsic PEEP (with beneficial effects on triggering).
How does NIV reduce afterload?
Non-invasive ventilation in acute cardiogenic pulmonary oedema. During systole, NIV increases the intrathoracic pressure and reduces venous return, thus decreasing the right and left ventricular preload; in diastole, NIV increases the pericardial pressure, reduces PTM, and thus decreases afterload.
Why do we use non-invasive ventilation?
Non-invasive ventilation can be used to treat acute or chronic respiratory failure. Delivered through a face mask, it provides positive pressure to increase a patient's lung volume, reduce the work of breathing and improve overall gas exchange.
Is NIV same as BiPAP?
NIV is the same way. BIPAP is the application of a two different levels of pressure. There is a lower pressure that is there during expiration (EPAP) and then the pressure increases to a higher level during inspiration (IPAP).
Is BiPAP good for COPD patients?
BiPAP machines provide two different levels of air pressure, which makes breathing out easier than it is with a CPAP machine. For this reason, BiPAP is preferred for people with COPD. It lessens the work it takes to breathe, which is important in people with COPD who expend a lot of energy breathing.
How long NIV can be given?
Most patients will only use NIV for parts of the day or night. However, some are dependent on NIV 24 hours of the day. For these patients, withdrawal of their NIV may cause distressing symptoms and death may occur soon after withdrawal. For these reasons forward planning is required.
When would you use a BiPAP for COPD?
If you have moderate to severe COPD, you may use a BiPAP machine at the hospital to help with sudden, intense symptoms. You can also use them at home to help with sleep. They'll keep your blood oxygen levels up and remove carbon dioxide. Just remember that BiPAP is not always helpful for COPD.
When do you start BiPAP for COPD?
Indications for BiPAP? Substantial respiratory distress or tachypnea (respiratory rate >~30/min). Somnolence due to hypercapnic encephalopathy, as a result of COPD exacerbation.
How often should you record observations on NIV chart?
Record observations on NIV Observation Chart every 15 minutes for the first hour, evaluate thereafter:
What to do if patient is not tolerant of NIV?
If patient is not tolerant of, or refuses NIV, rediscuss management with senior medical staff.
What is the oxygen level needed to maintain a spO2 of 88-92%?
OXYGEN = if supplementary oxygen required, set at 4L/min and titrate as necessary to maintain SpO 2 88-92%.
When should arterial blood gases be checked?
Arterial blood gases must be checked prior to starting NIV and whilst the patient is on controlled FiO2.
What is NIV in medical terms?
Non-invasive ventilation (NIV) is the application of respiratory support via a sealed face-mask, nasal mask, mouthpiece, full face visor or helmet without the need for intubation. In the modern era it implies the application of positive airway pressure, however some classifications include the application of a negative-pressure generator to ...
What is NIV used for?
Pre-oxygenation prior to intubation. In reality, NIV is often used for a combination (to varying extents) of hypoxaemia, hypercapnia and respiratory weakness regardless of the underlying diagnosis.
Why is NIV important?
NIV decreases resource utilisation compared with invasive ventilation and avoids the associated complications. Patient selection and a well-designed clinical protocol are important to avoid delaying intubation in patients who are not suitable for and/or failing NIV.
What is CPAP for cardiothoracic patients?
CPAP improves oxygenation and respiratory rate in general surgical and cardiothoracic patients with mild hypoxaemia.
How many RCTs are there for COPD?
COPD – RCTs and Cochrane review (14 RCTs) showed significant improvement in intubation rates, complications, length of hospital stay and mortality rates for NIV compared with invasive ventilation
When to use NIV?
Use NIV as a planned strategy post-extubation in selected patients and as ventilatory support for patients with respiratory failure and treatment directives limiting care. Avoid the use of NIV to delay or withhold intubation in those who need it.
How does extravascular lung water get back into interstitial space?
also allows for redistribution of extravascular lung water back into interstitial space through recruitment and surfactant production
What is NIV ventilation?
Non-invasive ventilation (NIV) refers to the provision of ventilatory support through the patient's upper airway using a mask or similar device. This technique is distinguished from those which bypass the upper airway with a tracheal tube, laryngeal mask, or tracheostomy and are therefore considered invasive. In this document NIV refers to non-invasive positive pressure ventilation, and other less commonly used techniques such as external negative pressure or rocking beds will not be discussed. (NIPPV is an alternative abbreviation but it is more cumbersome and involves ambiguity as to whether “N” is for “non-invasive” or “nasal”.)
What is NIV in hospitals?
Non-invasive ventilation (NIV) works – an evidence-based verdict. NIV can be used in any hospital given the following minimum facilities: A consultant committed to developing an NIV service. Nurses on a respiratory ward, high dependency unit, or intensive care unit who are keen to be involved in NIV.
What is NIV used for?
Within a few years of its introduction, NIV was starting to be used in acute hypercapnic respiratory failure and in patients with abnormal lungs rather than an impaired respiratory pump.
Why is NIV important?
NIV is becoming established as an important modality in the management of acute respiratory failure. The skills required are easily learnt and the equipment required is relatively inexpensive. If an acute NIV service is not provided, the shortage of ICU beds means that some patients will die because facilities to ventilate them invasively are not available. Even if they are intubated, some patients will die unnecessarily from complications such as pneumonia which they would not have developed if they had been ventilated non-invasively. These factors must be weighed against the potential disadvantages of an acute NIV service, the most important of which is that severely ill patients might receive NIV when intubation and invasive ventilation would be more appropriate.
Why use NIV masks?
One of the first descriptions of the use of NIV using nasal masks was for the treatment of hypoventilation at night in patients with neuromuscular disease. 1,2 This has proved to be so successful that it has become widely accepted as the standard method of non-invasive ventilation used in patients with chronic hypercapnic respiratory failure caused by chest wall deformity, neuromuscular disease, or impaired central respiratory drive. It has largely replaced other modalities such as external negative pressure ventilation and rocking beds.
How does oxygen enrichment work in NIV ventilators?
NIV ventilators entrain room air and, on most machines, oxygen enrichment requires oxygen to be fed proximally into the circuit or directly into the mask. An Fi o2 of about 35% can be achieved, but the flow rate of oxygen required will vary depending on the flow rate of air from the ventilator as it attempts to reach the set pressure, and the magnitude of any leaks in the circuit. An oxygen analyser inserted into the ventilator tubing gives unreliable information and an oximeter to guide oxygen enrichment is more reliable. Higher enrichment requires premixing which necessitates a high pressure oxygen supply. This is only available with ventilators designed for ICU use such as the Respironics Vision or volume control machines.
How successful is NIV?
Soo Hoo et al80 in a small study (14 episodes in 12 patients), in which NIV was successful in 50% of cases, found that there were no differences in age, prior pulmonary function, baseline arterial blood gas tensions, admission arterial blood gas tensions, or respiratory rate between those patients successfully treated and those who failed NIV. Unsuccessfully treated patients had more severe illness than successfully treated patients, as indicated by a higher Acute Physiology and Chronic Health Evaluation (APACHE) II score, and had pneumonia or excess secretions. In addition, they were edentulous and had pursed lip breathing—factors that prevented adequate mouth seal and contributed to greater mouth leaks than in successfully treated patients. Successfully treated patients were able to adapt more rapidly to the nasal mask and ventilator, with greater and more rapid reduction in Pa co2, correction of pH, and reduction in respiratory rate. In a study of NIV in 17 consecutive patients with respiratory failure of various causes, 81 NIV was successful in 47%; patients successfully ventilated with NIV had a higher Pa co2, a lower pH (7.33 (0.03) v 7.45 (0.08); p=0.02), and a lower alveolar–arterial oxygen difference (P (A–a) o2) (144 (46) mm Hg v 265 (18) mm Hg; p=0.01), suggesting that CO 2 retention without major hypoxaemia is a better indication for NIV than severe hypoxaemia alone. In both groups of patients gas exchange improved after 1 hour on NIV, but such values were not improved on the first day in patients who failed with NIV.
