Resp: Oxygen, Antihistamines, Mucolytic

Question 1

Indications of oxygen?

Answer 1

Acute hypoxaemia (increase tissue oxygen delivery)

Pneuomothorax (accelerate reabsorption of pleural gas)

Carbon monoxide poisoning (reduce carboxyhaemoglobin half-life)

Chronic hypoxaemia (long-term oxygen therapy)

Question 2

Adverse effects of oxygen?

Answer 2

Discomfort of a face mask.

Lack of water vapour:
- dry mouth (humidification improves this)

Hyperoxaemia

Question 3

Warnings of oxygen?

Answer 3

Chronic type 2 resp failure pts (e.g. severe COPD):
- partial pressure of CO2 can increase because their body has already adapted to persistent hypoxaemia and hypercapnia.
→ this can lead to respiratory acidosis, depressed consciousness, and worsened tissue hypoxia.

Oxygen accelerates combustion.
→ FIRE risk if exposed to heart source or naked flame, including smoking.

Question 4

Interactions of oxygen?

Answer 4

None

Question 5

Monitoring of oxygen?

Answer 5

Frequent oxygen saturation monitoring.

Adjust device and/or flow rate as necessary to keep oxygen saturation in target range.

ABG measurement is essential in pts with critical illness -e.g. chronic type 2 resp failure, or risk of hypercapnoea, or hypoxaemia.

Question 6

Pt education of oxygen?

Answer 6

Explain that the face mask or nasal cannulae should be kept in place continuously.

May briefly be removed to allow eating and drinking.

Report any discomfort -can improve this by changing device or flow rate.

Question 7

Indications of antihistamines?

Answer 7

1st line: allergies, hay fever

Relief of itchiness and hives (e.g. insect bites and drug allergies)

Anaphylaxis (after giving adrenaline)

May be used for n+v

Question 8

Examples of antihistamines?

Answer 8

cetirizine
loratadine
fexofenadine
chlorphenamine

Question 9

Adverse effects of antihistamines?

Answer 9

‘first generation’ antihistamines cause SEDATION.

‘second generation’ does NOT have this effect because it does not cross blood-brain barrier.

Question 10

Warnings of antihistamines?

Answer 10

Avoid sedating antihistamine in severe liver disease.
→ can lead to hepatic encephalopathy

Question 11

Examples of first generation antihistamine?

Answer 11

chlorphenamine

Question 12

Examples of second generation antihistamine?

Answer 12

loratadine
cetirizine
fexofenadine

Question 13

Interaction of antihistamines?

Answer 13

None significant.

Question 14

Monitoring of antihistamines?

Answer 14

Assess for allergic symptoms like rash.

Enquire about side effects.

Question 15

Pt education of antihistamines?

Answer 15

Aims to help relieve their allergic symptoms or their itchy rash/hives.

Hay fever tablets -improve sneezing, itchiness, runniness, but not nasal congestion.

Chlorphenamine -may feel sleepy or lose concentration.
→ so AVOID taking it before driving or any activity that requires concentration.

Avoid combing medication with alcohol -may exacerbate the effect.

Question 16

Indications of mucolytic (carbocisteine)?

Answer 16

Paracetamol poisoning
Prevent renal injury from contrast nephropathy
Reduce viscosity of respiratory secretions

Question 17

Adverse effects of mucolytic (carbocisteine)?

Answer 17

Anaphylactoid reaction (but involves histamine release independent of immunoglobulin E (IgE) antibodies)
- nausea
- tachycardia
- rash
- wheeze

Once reaction has settled, give antihistamine +/-bronchodilator).

Nebulised mucolytic -BRONCHOSPASM
→so give bronchodilator (salbutamol) beforehand.

Question 18

Warnings of mucolytic (carbocisteine)?

Answer 18

Hx of an anaphylactoid reaction to acetylcysteine does NOT contraindicate its use in future.

Question 19

Interactions of mucolytic (carbocisteine)?

Answer 19

None significant.

Question 20

Monitoring of mucolytic (carbocisteine)?

Answer 20

In paracetomol poisoning:
- monitor for anaphylactoid reaction

INR, serum ALT, and creatinine should be measured at presentation and after giving antihistamine.
→ track liver injury

Question 21

Pt education of mucolytic (carbocisteine)?

Answer 21

Offering paracetamol antidote.
→ given slowly through a drip over 21 hours.

Avoid interruptions to the tx.

Alert staff if you notice signs of reaction, e.g. rash, nausea, wheeziness.
→ infusion can be interrupted and tx given.