In patients who are in the last weeks to days of life, is routine continuous pulse‑oximetry monitoring appropriate?

Oxygen Saturation Monitoring in the Last Weeks and Days of Life

In general, there is no role for monitoring oxygen saturation in comfort-focused care during the last few days of life—if the patient appears comfortable, oxygen levels are irrelevant and should not influence care. 1

Core Principle: Comfort Over Numbers

The British Thoracic Society explicitly states that oxygen saturation monitoring should be discontinued in dying patients receiving comfort-focused care. 1 This recommendation fundamentally shifts the clinical paradigm from physiological parameters to observable comfort as the primary endpoint.

The rationale is straightforward:

• Breathlessness in palliative care patients shows little correlation with actual oxygen saturation levels 1
• Vital signs, including oxygen saturation, can remain normal even in the last days of life, making them unreliable predictors of death 2
• Blood pressure and oxygen saturation naturally decrease in the final three days of life as part of the dying process, not as a treatable emergency 2

When Monitoring Parameters Actually Matter

Focus monitoring exclusively on comfort parameters rather than vital signs: 1

• Respiratory distress (labored breathing, use of accessory muscles, tachypnea)
• Signs of pain (grimacing, moaning, restlessness)
• Agitation or terminal restlessness

These observable signs of suffering require intervention, regardless of what the pulse oximeter displays. 1

The Problem with Routine Monitoring in Dying Patients

Continuing oxygen saturation monitoring in the last days creates several clinical pitfalls:

• It medicalizes the natural dying process by treating normal physiological decline as a problem requiring intervention 1
• It may prompt unnecessary interventions that increase discomfort (oxygen masks, nasal cannulae causing dryness and irritation) without improving quality of life 1
• It distracts from what matters—the patient's subjective experience of comfort and dignity 1

Practical Algorithm for End-of-Life Oxygen Decisions

For patients in the last weeks to days of life:

1. Is the patient imminently dying? (bedbound, unconscious, unable to swallow, profound weakness, changing breathing patterns) 3

   • Yes → Discontinue routine vital sign monitoring including oxygen saturation; monitor only for signs of distress 1
   • No → Proceed to step 2

2. Is the patient hypoxaemic (SpO₂ consistently <90%)? 1

   • Yes → Consider oxygen only if patient reports significant relief of breathlessness from oxygen 1
   • No → Do not use oxygen; try opioids and non-pharmacological measures (hand-held fan, treating anxiety) first 1

3. If oxygen is being used, does it provide subjective benefit? 1

   • No benefit or disadvantages outweigh benefits → Discontinue oxygen 1
   • Clear benefit → Continue with minimal monitoring focused on comfort 1

Evidence Strength and Nuances

The recommendation against monitoring is based on level 1+ evidence showing no difference between oxygen and air for breathlessness relief in non-hypoxaemic palliative patients, and level 2+ evidence showing breathlessness correlates poorly with oxygen saturation. 1 While the specific recommendation against monitoring is grade D (expert opinion), it flows logically from the higher-level evidence that oxygen saturation is clinically irrelevant to comfort in this population.

A critical caveat: This guidance applies specifically to comfort-focused care in the dying phase. 1 For palliative patients who are not imminently dying and who have potentially reversible conditions, standard monitoring may still be appropriate. 1

What to Do Instead

Prioritize these interventions over monitoring: 1

• Early involvement of palliative care specialists and physiotherapists
• Comprehensive assessment of anxiety and other contributing factors to breathlessness
• Low-dose opioids for breathlessness relief
• Trial of hand-held fan before considering oxygen
• Treatment of underlying anxiety or existential distress 3

For patients receiving palliative sedation for refractory symptoms, monitoring should focus exclusively on comfort parameters, not respiratory rate or oxygen saturation. 1 A gradual deterioration of respiration is expected as patients near death and should not trigger interventions. 1