Both non-invasive ventilation (NIV) and continuous positive airway pressure (CPAP) machines are used to treat respiratory problems in patients. They offer ventilatory support when the person remains hypoxic despite being provided with medical aid. The devices are commonly found in respiratory wards, intensive care units, and high dependency units. Irrespective of their similarities, the treatment options are quite different from each other for the following reasons. Have a look!

NIV vs CPAP
What is NIV?
NIV is a form of respiratory treatment that offers breathing support by delivering air, usually with added oxygen, via a facemask by positive pressure. The term is also used when referring to the bi-level positive airway pressure machine (BiPAP). The device provides oxygen to your lungs at different pressures based on inspiration and expiration. Since the inspiratory positive airway pressure is higher than the expiratory positive airway pressure, ventilation is given by iPAP. On the other hand, ePAP uses under-ventilated or collapsed alveoli to exchange gases and assists removal of exhaled gas.

Primarily, NIV treatment is provided for type 2 respiratory failure that happens in case of COPD exacerbation.

What is CPAP?
The CPAP machine delivers air to your respiratory system at a constant rate for inspiration and expiration. Thus, it is not a type of ventilation. Instead, it splints the airway open. In a chronic setting, a CPAP machine supports breathing in case of severe obstructive sleep apnea. On the other hand, in an acute setting, it aids with type 1 respiratory failure that happens with acute pulmonary oedema.

When are NIV and CPAP started?

Indications for beginning NIV treatment include:

. If the patient has COPD with respiratory acidosis.
. Suffering from weaning from tracheal intubation.
. The patient has a hypercapnic respiratory failure that is secondary to chest wall deformity and neuromuscular
disease.
Indications for beginning CPAP treatment include:
The person has obstructive sleep apnea.
The patient is suffering from cardiogenic pulmonary oedema.
In case of pneumonia as an interim measure before invasive ventilation begins.

Consent for NIV and CPAP treatment
If there is a need for NIV or CPAP, you should discuss it with the patient and gain their consent. If the person is unwell and cannot make this decision on his own, the medical team should discuss it with the family.

Contraindications
Here are certain contraindications that suggest you should not start with the NIV/CPAP treatment:
. If the patient is vomiting.
. The person reports being confused or agitated.
. The patient has had recent facial, gastrointestinal, or upper airway surgery.
. If he has impaired consciousness and is drifting in and out of awareness.
. In case of bowel obstruction.
. If the patient has suffered from facial burns or trauma.

Monitoring
Once the CPAP or NIV treatment has been commenced, the following should be measured:
. ECG
. Respiratory rate
. Consciousness level
. Pulse
. Respiratory rate
. Blood pressure
. Pulse
. Arterial blood gas

NIV and CPAP come in use for providing breathing support to the patient. However, despite their similarities, both forms of treatment are different.