Beta-2 agonists relax bronchial smooth muscle; expect tachycardia, tremor and lower potassium.
Before you read
Test yourself first: 5 questions
Question 1 of 5
Which finding best indicates that a patient in respiratory distress is progressing to respiratory failure?
Answer: A. Distress is a patient still compensating: anxious, fast, working hard, upright. Failure begins when the effort can no longer be sustained — the patient tires, carbon dioxide climbs, the level of consciousness falls and the rate slows. A slowing rate in a patient who was working hard is not improvement; it is exhaustion, and it calls for assisted ventilation.
Question 2 of 5
What is the minute volume of an adult breathing 8 times a minute with a tidal volume of 500 mL?
Answer: A. Minute volume is respiratory rate multiplied by tidal volume: 8 x 500 mL = 4,000 mL each minute. Adding the two numbers (508) or dividing them (62.5) are the classic arithmetic slips; 6,000 mL is what a normal adult moves at 12 breaths a minute, which is exactly why a rate of 8 matters.
Question 3 of 5
A patient treated for mild respiratory distress is now comfortable on a nonrebreather mask with a saturation of 100%. What is the most appropriate change?
Answer: A. Oxygen is a treatment titrated to effect; for most patients the target is roughly 94 to 98%, and sustained excess oxygen carries its own harms. Keeping full flow ignores that target, stopping monitoring abandons reassessment of a patient who was recently in distress, and a saturation of 100% cannot be improved.
Question 4 of 5
A 2-month-old with heavy nasal congestion is working hard to breathe and feeding poorly. The reason a blocked nose matters so much at this age is that infants:
Answer: A. Young infants are near-obligate nasal breathers and do not reliably switch to the mouth, so occluded nares alone produce genuine respiratory distress and interrupt feeding. Gentle suction of the nostrils can transform the picture, which is why it is an early and high-yield intervention rather than a cosmetic one.
Question 5 of 5
An alert adult with an uncomplicated injury has a room-air saturation of 98%, normal work of breathing and no respiratory complaint. Supplemental oxygen should be:
Answer: A. Oxygen is a treatment for hypoxia, and a patient who is not hypoxic gains nothing from it while excess oxygen carries its own risks in several conditions. Reassessment, not a mask, is what catches a later deterioration — giving it pre-emptively removes the very finding you would have used to detect one.
Keep the streak going with more questions like these, each with a full rationale.
What is respiratory pharmacology?
Knowing which class hits which target explains why a nebulized bronchodilator fixes wheezing, why steroids are given early but work late, and why stridor needs a different drug.
Key points to remember
- Beta-2 agonists relax bronchial smooth muscle; expect tachycardia, tremor and lower potassium.
- Anticholinergics add bronchodilation by blocking vagal tone; best paired with a beta-2 agonist.
- Corticosteroids reduce inflammation but take hours — give early so the effect arrives in time.
- Magnesium relaxes smooth muscle and is reserved for severe or refractory bronchospasm.
- Nebulized epinephrine shrinks swollen upper-airway tissue in croup and angioedema.
Field priorities
- In severe asthma with poor air movement, consider intramuscular epinephrine alongside nebulized therapy.
- Reassess breath sounds, work of breathing and end-tidal CO2 after every treatment.
- Do not delay CPAP or ventilatory support while waiting for drugs to work.
Coaching the patient
- Wheezing that fades as air movement falls is worsening, not improving — a quiet chest in severe asthma means almost no air is moving.
Red flags: act now
- Silent chest with fatigue
- Rising end-tidal CO2 in an asthmatic
- Stridor at rest in a child
Respiratory Pharmacology: FAQs
What are the priority actions for Respiratory Pharmacology in the field?
In severe asthma with poor air movement, consider intramuscular epinephrine alongside nebulized therapy. Reassess breath sounds, work of breathing and end-tidal CO2 after every treatment. Do not delay CPAP or ventilatory support while waiting for drugs to work.
What findings in Respiratory Pharmacology change your plan or your transport decision?
Silent chest with fatigue. Rising end-tidal CO2 in an asthmatic. Stridor at rest in a child.
What do I need to know about Respiratory Pharmacology for the NREMT?
Beta-2 agonists relax bronchial smooth muscle; expect tachycardia, tremor and lower potassium. Anticholinergics add bronchodilation by blocking vagal tone; best paired with a beta-2 agonist. Corticosteroids reduce inflammation but take hours — give early so the effect arrives in time. Magnesium relaxes smooth muscle and is reserved for severe or refractory bronchospasm.
What should the crew communicate or document for Respiratory Pharmacology?
Wheezing that fades as air movement falls is worsening, not improving — a quiet chest in severe asthma means almost no air is moving.
