[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Nursing](https://durgical.com/en/nursing/) › [Critical care](https://durgical.com/en/nursing/areas/critical-care/) › Noninvasive ventilation (CPAP, BiPAP) and high-flow nasal oxygen: mask fit, skin, tolerance and failure signs # Noninvasive ventilation (CPAP, BiPAP) and high-flow nasal oxygen: mask fit, skin, tolerance and failure signs - Procedure Fit the interface well, protect the skin, support the patient and check early and often whether it is working or intubation is needed. Updated Nov 13, 2026 ## Key points - Reassess about every hour at first and every 2–4 h once stable: RR, SpO2, work of breathing and consciousness. - Failure signs: ongoing distress, SpO2 45 mmHg, falling or altered consciousness — tell the doctor; intubation must not be delayed. - Mask pressure injuries appear mostly on the nasal bridge, forehead and ears; long use and low albumin raise the risk. - Fill humidifiers with sterile or distilled water, never tap water. - Masks can cause claustrophobia and high-flow cannulas nasal discomfort: explain, adjust and support. ## What it is High-flow nasal oxygen delivers heated, humidified oxygen up to 100% at flows of up to 60 L/min through a wide nasal cannula. CPAP gives one continuous pressure; BiPAP gives two levels, higher during inspiration and lower during expiration. In acute care these devices can avoid intubation in some patients with respiratory failure, but they need close monitoring, trained staff and a plan for rescue. They must never delay intubation when it is needed. The respiratory therapist or the doctor sets them up; the nurse keeps the interface working, protects the skin, supports the patient and watches for failure. Basic oxygen devices are on the oxygen therapy page. ## Indications - Acute hypoxaemic respiratory failure without an immediate need for intubation (high-flow oxygen, CPAP or NIV). - Acute respiratory failure with hypercapnia, especially in COPD or left heart failure (NIV). - Preoxygenation before intubation. - Awake prone positioning in selected hypoxaemic patients receiving oxygen, high flow or NIV. ## Contraindications and precautions - Not a substitute for intubation when there is severe hypoxaemia despite oxygen, severe hypercapnia despite NIV, haemodynamic instability or a need to protect the airway. - Emergency signs (obstructed breathing, central cyanosis, shock, seizures, reduced consciousness) call for urgent airway management. - These devices can spread aerosols: follow the infection precautions of the protocol. - The patient needs equipment and staff for close monitoring and rescue nearby. ## Equipment - The device and circuit, set up by the respiratory therapist or as the protocol says. - An interface of the right size: high-flow nasal cannula, or nasal, oronasal mask or helmet for NIV. - Humidifier with sterile or distilled water. - Protective dressings for the skin under the interface, as the protocol says. - Pulse oximetry and a monitor; suction, bag-mask and intubation equipment nearby. ## Step by step (and why) - Explain the device and what the patient will feel — anxiety and claustrophobia reduce tolerance. - Sit the patient well up and choose an interface of the right size — a poor fit leaks and presses on the skin. - Protect the nasal bridge, forehead and ears with dressings as the protocol says — they are the commonest injury sites. - Fit the mask or cannula firmly without overtightening — tight straps injure the skin; big leaks waste the support. - Confirm settings, oxygen and humidifier water against the order — the gas must be humidified and the support correct. - Reassess about every hour at first, then every 2–4 h when stable: RR, SpO2, effort and consciousness — failure shows early. - Send blood gases as ordered, especially with hypercapnia — pH and PaCO2 show whether NIV is working. - Inspect the skin under the interface every shift and relieve pressure as the protocol says — longer use raises the risk. - Keep suction, bag-mask and intubation equipment ready — failure must be treated without delay. - Record settings, tolerance, skin, vital signs and response. ## Complications - Pressure injury of the nasal bridge, forehead and ears. - Intolerance, anxiety and claustrophobia with masks; nasal discomfort with high flow. - Delayed intubation when the device is failing. - Exposure of staff to aerosols without the right precautions. ## Next step: when to call for help - Ongoing distress, SpO2 below 90%, pH below 7.30, PaCO2 above 45 mmHg or worsening consciousness: call the doctor now. - The patient cannot tolerate the interface or keeps removing it: report it; another interface or another plan is needed. - Skin redness that does not fade or broken skin under the interface: report and record it. - Any emergency sign: call for urgent airway management. ## Test yourself Think of the answer, then tap the question to see it. ## What is the difference between CPAP and BiPAP? CPAP gives one continuous pressure throughout breathing; BiPAP gives two levels, higher during inspiration and lower during expiration. ## Which signs mean noninvasive support is failing? Ongoing distress, SpO2 below 90%, pH below 7.30, PaCO2 above 45 mmHg and falling or altered consciousness. ## Where do NIV mask pressure injuries usually appear? Mostly on the nasal bridge, forehead and ears. Longer time on the device and low albumin raise the risk. ## What water goes into the humidifier of a CPAP or high-flow device? Sterile or distilled water, never tap water. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/nursing/noninvasive-ventilation-and-high-flow-nasal-oxygen-mask-fit-skin-tolerance-and-f/) ## Connections ## Related 4 - [Oxygen therapy: devices, flows and safety](https://durgical.com/en/nursing/oxygen-therapy-devices-flows-and-safety/) - [Weaning from the ventilator: readiness, the spontaneous breathing trial, extubation and the hours after](https://durgical.com/en/nursing/weaning-from-the-ventilator-readiness-the-spontaneous-breathing-trial-extubation/) - [Preventing pressure injuries: risk scales, repositioning and skin care](https://durgical.com/en/nursing/preventing-pressure-injuries-risk-scales-repositioning-and-skin-care/) - [Nursing care of the patient with COPD: exacerbations, controlled oxygen, breathing techniques and inhaler teaching](https://durgical.com/en/nursing/nursing-care-of-the-patient-with-copd-exacerbations-controlled-oxygen-breathing/) ## Related conditions 2 - [Chronic obstructive pulmonary disease (COPD)](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/) - [Acute respiratory failure (hypoxaemic and hypercapnic)](https://durgical.com/en/conditions/acute-respiratory-failure/) [← All of nursing](https://durgical.com/en/nursing/) Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order. Sources: [Nursing Skills, 11.3: Oxygenation Equipment](https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/11%3A_Oxygen_Therapy/11.03%3A_Oxygenation_Equipment) (Open RN, Chippewa Valley Technical College (via LibreTexts), 2021); [Clinical management of COVID-19: living guideline, 18 August 2023](https://www.who.int/publications/i/item/WHO-2019-nCoV-clinical-2023.2) (World Health Organization, 2023); [Clinical care for severe acute respiratory infection: toolkit, update 2022 (COVID-19 adaptation), tool 9.3](https://www.who.int/publications/i/item/clinical-care-of-severe-acute-respiratory-infections-tool-kit) (World Health Organization, 2022); [Incidence and risk factors of noninvasive ventilation device-related pressure skin injuries: a retrospective study](https://pmc.ncbi.nlm.nih.gov/articles/PMC12079089/) (Health Science Reports (open access, PMC), 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/nursing/noninvasive-ventilation-and-high-flow-nasal-oxygen-mask-fit-skin-tolerance-and-f/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/nursing/noninvasive-ventilation-and-high-flow-nasal-oxygen-mask-fit-skin-tolerance-and-f/