Patients with COPD and other risk factors for hypercapnia who develop critical illness should have the same initial target saturations as other critically ill patients pending the results of blood gas results after which these patients may need controlled oxygen therapy with target range 88–92% or supported ventilation if there is severe hypoxaemia and/or hypercapnia with respiratory acidosis.

In terms of nebulizers versus inhaler devices, there have actually been a lot of studies comparing the two. The research based on children with asthma actually shows a better effect with an inhaler (with a spacer attached) compared to a nebuliser. In the adult population, the evidence shows there is no difference between the two in terms of outcomes. But for some reason, clinicians feel like nebulisers work better. Maybe the same way we incorrectly believe that normal saline nebulisers actually independently mobilise mucous? It is not actually reflected in the evidence, but sometimes we see something working and we feel that it is actually better. A change in delivery device (without an increase in O2 therapy) does not require review by the medical team. Use reservoir masks at 15L/minute O 2 flow initially in all patient groups pending arterial blood gas (ABG) analysis. B1. Fully trained clinicians should assess all acutely ill patients by measuring respiratory rate, pulse rate, blood pressure, temperature and assessing circulating blood volume and anaemia. Expert assistance from specialists in intensive care or from other disciplines should be sought at an early stage if patients are thought to have major life-threatening illnesses and clinicians should be prepared to call for assistance when necessary including a call for a 999 ambulance in prehospital care or a call for the resuscitation team or intensive care unit (ICU) outreach team in hospital care (grade D).

Oxygen therapy should be increased if the saturation is below the desired range and decreased if the saturation is above the desired range (and eventually discontinued as the patient recovers). The presence of a normal SpO 2 does not negate the need for blood gas measurements especially if the patient is on supplemental oxygen therapy. Pulse oximetry will be normal in a patient with normal oxygen tension (PO 2) but abnormal blood pH or carbon dioxide tension PCO 2 or with a low blood oxygen content due to anaemia. For this reason, blood gases and full blood count tests are required as early as possible in all situations where these measurements may affect patient outcomes. Best practice is to prescribe a target range for all hospital patients at the time of admission so that appropriate oxygen therapy can be started in the event of unexpected clinical deterioration with hypoxaemia and also to ensure that the oximetry section of the early warning score (EWS) can be scored appropriately.

Patients should be monitored accurately for signs of improvement or deterioration. Nurses should also monitor skin colour for peripheral cyanosis and respiratory rate. F14. High concentrations of oxygen should be avoided in patients with stroke, unless required to maintain normal oxygen saturation. Aim at an oxygen saturation of 94–98% or 88–92% if the patient is at risk of hypercapnic respiratory failure (grade D). Few case reports show absorption of the interstitial abnormalities including reticulation, GGO and patchy consolidation, indicating the potential use of Pirfenidone as an effective medication for the post-inflammatory pulmonary fibrosis of COVID-19 patients. Admit to regional CF centre if possible, if not discuss with regional centre or manage according to protocol agreed with regional CF centre. Ideally use ‘alert cards’ to guide therapy. Increase Venturi mask flow by by up to 50% if respiratory rate is above 30bpmCan be used for long-term oxygen use, whilst allowing the child to vocalise and eat. The concentration is often not controlled resulting in a low inspiratory oxygen concentration. The use of nasal cannulae can cause dermatitis and mucosal drying (Joint Formulary Committee, 2006). Nasal cannula oxygen does not need to be humidified. I would then educate the patient that “breathing in is going to become a lot easier now, but they have to focus on breathing out”. Otherwise, you start to get the blowfish effect in that not all the air that they breathe in comes out. Also the higher your pressure support gets, the more it is going to push the mask off your patient resulting in an air leak…so just be aware of that as you are titrating up to meet the inspiratory flow demand of your patient. And then you can set the FiO2 on the machine to whatever is required to meet the oxygenation demands of your patient.

High-flow nasal oxygen (HFNO): compared to a non-rebreather mask, can deliver oxygen at a greater FiO 2 (up to 100%) and flow rate (up to 60L/min). Usually only available in high-dependency/intensive care environments. Nakane M. Biological effects of the oxygen molecule in critically ill patients. Journal of Intensive Care. Published in 2020. Available from: [ LINK] Any changes in oxygen should be documented on the patient’s observation chart and signed for by nursing staff on drug chart.

SECTION 11: PRESCRIPTION, ADMINISTRATION AND MONITORING OF OXYGEN THERAPY

F11. In anaemia, aim at an oxygen saturation of 94–98% or 88–92% if the patient is at risk of hypercapnic respiratory failure (grade D). A non-rebreather mask is used in emergency situations to prevent hypoxemia, also known as low blood oxygen. Conditions that disrupt your lungs’ ability to uptake oxygen or your heart’s ability to pump blood can cause low blood oxygen levels. A normal or high oximetry reading should be disregarded because saturation monitors cannot differentiate between carboxyhaemoglobin and oxyhaemoglobin, owing to their similar absorbances.