COPD and Asthma, and the Oxygen Decisions Between Them

Two obstructive conditions, two different stems. Asthma is episodic and reversible, and the patient is usually well between attacks. COPD is chronic and progressive, and the patient lives with a baseline they have adapted to. That difference drives almost every option you will be offered.

How the two present differently on paper

An asthma stem tends to be an event. There is a trigger, a sudden onset, wheezing, chest tightness and a cough, and a patient who was fine yesterday and is not fine now.

A COPD stem tends to be a life. Years of history, a barrel chest, a chronic productive cough, breathlessness on exertion that has slowly worsened, and a patient who has learned to sit forward to breathe.

That history changes what counts as normal for this person. A saturation reading you would treat urgently in one patient may be close to another patient's usual, which is why the stem often tells you the baseline.

Read for the baseline every time. If the stem gives it to you, it is load-bearing information rather than scene setting.

The oxygen decision is where the exam separates them

In an acute asthma attack, hypoxemia is treated. Oxygen goes on, the bronchodilator is the priority intervention, and nobody withholds it while the airway is narrowing.

In COPD, oxygen is titrated toward a prescribed target rather than turned up to the maximum. Long-standing carbon dioxide retention changes how some patients respond to high concentrations, and the goal is enough oxygen, not all of it.

We are not printing a target saturation range in this post, because the range that governs your patient is the one written in the orders and it is not a number this site can source for you.

Here is the sentence that keeps students safe. Never withhold oxygen from a hypoxic patient. Titrating is not the same as refusing, and an option that leaves someone hypoxic to protect a theory is not the correct one.

Delivery device matters too. Low-flow devices are titratable and comfortable for long-term use, while higher-flow and reservoir systems exist for the patient whose need has outrun them, and the escalation is a nursing observation as much as a prescription.

Positioning and breathing teaching

Positioning is free and it is frequently the correct first action. Upright and forward opens the chest, drops the diaphragm and lets accessory muscles work with gravity rather than against it.

Pursed-lip breathing belongs to the COPD patient. Breathing in through the nose and out slowly through pursed lips holds a small back pressure in the airway, which keeps floppy airways from collapsing before the air has left.

The teaching point is the exhale. Longer out than in, slow and unhurried, practised when the patient is calm rather than invented during an attack.

Diaphragmatic breathing, pacing activities and energy conservation fill out the rest of the COPD teaching. Sit down to wash and dress, put the heaviest task in the best part of the day, and rest before exhaustion rather than after it.

Infection prevention belongs in that conversation too, since a chest infection in a patient with limited reserve is a hospital admission. Hand hygiene, keeping current with recommended vaccination, and knowing which change in sputum warrants a call are all practical teaching.

That last distinction is worth drilling. A patient reaching for the maintenance inhaler during an attack is a teaching failure that shows up in stems constantly.

The medication teaching that keeps being tested

Inhaler technique is examined more often than inhaler pharmacology, because technique is the part nursing owns. A perfectly prescribed drug delivered to the back of the throat is a wasted dose.

Teach it as a sequence and watch it performed rather than described.

A spacer solves most technique problems at once, and it is not only for children. Anyone who struggles to coordinate the actuation with the breath will get more drug into the lungs with one.

Rescue and maintenance is the other conversation. The patient needs to know which device treats symptoms now, which one prevents them, and that needing the rescue device more often than usual is information for the clinic rather than a reason to use it more.

Written action plans work the same way. The zones and the thresholds on them are set by the prescriber for that patient, and the nursing job is making sure the patient can say what they would do at each stage.

Which findings mean this is getting worse

Loud is not the same as dangerous. A wheeze requires moving air, so a chest that gets quieter while the patient works harder is describing less air movement, not less disease.

The findings that should worry you are the ones that look like tiring. Speaking in words rather than sentences, accessory muscle use, a rising then falling respiratory rate, drowsiness, and a patient who stops fighting.

That inversion is worth a post of its own, and it has one. The findings that precede measurable failure are set out in recognising respiratory failure before the numbers say so.

Altered consciousness has more than one explanation. A sudden change in speech, facial symmetry or one-sided strength is a different emergency with a different clock, described in stroke assessment and the time-sensitive actions.

The gases, briefly, and where they get read properly

StatPearls gives a normal arterial pH of 7.35 to 7.45 and a normal PaCO2 of 35 to 45 mmHg, and reference ranges vary slightly between laboratories, which is a sentence worth attaching to every value you quote.

A COPD patient with a long history may sit outside those figures and be at their own baseline, which is exactly why the interpretation order matters more than the values.

Interpreting a gas is a separate skill with a fixed sequence, worked through in arterial blood gases, a four-step reading order and, in shorter form, in reading ABGs in three steps.

Studying these two together

Study them as a pair. The contrast is the content, and revising either one alone wastes half the comparison that the exam is built on.

Where respiratory sits relative to the other systems, and why it gets studied early, is described in the med-surg reasoning order.