Oxygen is perhaps
the most common drug administered in medical emergencies. It requires careful
use in patients with exacerbations of chronic obstructive pulmonary disease
(COPD). This case report looks at the treatment of a patient that thought he
was “allergic” to oxygen, explores reasons for hypercapnia in certain patients
and looks at how treatment could have been improved.
· COPD is a group of lung diseases
characterised by non-reversible and progressive obstruction of airflow that interferes
with normal breathing.1 It is
a common condition and the second leading cause of emergency admission to
· Patients with COPD generally have
lower than normal SaO2 and in cases of exacerbation it is
recommended to maintain a SaO2 of 88-92% (GOLD, BTS ref, JRCALC)
This is due to the risk of hypercapnic respiratory failure in some patients
(BTS hypercapnic ref).
· Oxygen is legally a general sales
list medication that does not require a prescription. But in the context of
being administered by a healthcare professional oxygen requires accurate
documentation of dosage and clinical intentions.
· Oxygen is absorbed by passive
diffusion from alveoli into capillary beds and is distributed mostly bound to
haemoglobin. Oxygen is metabolised in cell mitochondria where it is essential
in the formation of ATP. The resulting carbon dioxide produced enables the
oxygen to be excreted via the lungs.
· Oxygen is indicated for hypoxemic
patients. Concentration is dictated by the condition being treated; guidelines
are available for common medical emergencies (JRCALC).
Patient: 58-year-old male, smoker, end-stage COPD, lives in residential
Presenting condition: Difficulty in breathing.
History of presenting condition: Struggling to breath, residential home
staff concerned. Increasing difficulty in breathing for past week, rigors, increased
cough and sputum production. Feels increasingly unwell.
Previous medical history: COPD, hypertension, diabetes.
Findings: The patient presented with low oxygen saturations (