MP324- COUGHING AND BREATHING PROBLEMS

Question 1

what happens with a cough

Answer 1

• deep inspiration followed by a build up of intra-thoracic pressure against a closed glottis
• glottis open and rapid expulsion of air and sound

500MPH

Question 2

causes of dry cough

Answer 2

asthma
cold
GERD
sleep apnea
vocal cord dysfunction
allergies
COVID

Question 3

causes of wet cough

Answer 3

cold
flu
lung infection
cystic fibrosis
COPD
acute bronchitis
bronchiectasis

Question 4

easing coughs originating above the larynx

Answer 4

often helped by meds which form a soothing coat over the inflamed membranous tissue
(DEMULCENT)

Question 5

easing coughs originating below the larynx

Answer 5

• eased by steam inhalation or water aerosol inhalations
• menthol, eucalyptus and benzoin tincture can help stimulate the secretion of a thin layer of mucus to protect the inflamed area
• menthol can block TRPV1 channels
• cough mixtures

Question 6

suppression of a cough centrally

Answer 6

• opioids can suppress neuronal activity in the medulla
• codeine and methadone: activates u-opioid receptors (help lung cancer) with pain relief and better sleep (sedation)
• dectromethorphan and pholcodeine: act via mu-opioid receptors and are anti-tussive without pain relief

Question 7

ATP as a key modulator of the cough reflex

Answer 7

• tussive stimuli from various various sources can increase calcium efflux, leading to ATP release from the open pannexin-1 channel
• ATP stimulates the P2X3 and P2X2 receptors on sensory neurones within the airway mucosa
• promising antitussive efficacy of P2X3 antagonists

Question 8

the problem with mucus

Answer 8

• during infection or illness, more mucus produced and glycoproteins in the mucus can change (MORE VISCOUS)
• in bronchiectasis and CF mucus is very viscous and not easily cleared
• COPD mucus plugs - no airflow below part of lungs

Question 9

mucolytics

Answer 9

N-acetylcysteine (NAC)
carbocysteine
dornase-a

Question 10

solution to excessive mucus

Answer 10

MUCO-ACTIVE DRUGS
- mucolytics
- expectorants encourage productive cough by stimulating secretion of mucus (more watery)
- Muco-kinetic drugs, cilia beat faster
- Muco-regulators

Question 11

Dornase-a MOA

Answer 11

• mucolytic enzyme
• used in CF
• can break down DNA polymers found in the thickened mucus and make it less viscous

Question 12

expectorant example

Answer 12

guaifenesin

Question 13

mucolytics MOA

Answer 13

break apart the di-sulphide bonds in the mucins, this decreases the viscosity of mucus

Question 14

muco-kinetic drug examples

Answer 14

beta-2 adrenergic agonists

Question 15

Muco-regulator drugs examples

Answer 15

anti-muscarinics
glucocorticoids

Question 16

surfactants MOA

Answer 16

produced from type II pneumocystis and lower surface tension on the alveolar surface - reduced inner pressure within the alveoli

Question 17

what happens without surfactant

Answer 17

the small alveoli would collapse and gas exchange would be severely compromised

also prevents so much fluid coming from the capillaries into the lungs (sealant)

Question 18

Infant respiratory distress syndrome

Answer 18

• occurs in 50% of neonates between 26-28 weeks but becomes less frequent with development
• alveoli collapse leaving larger spaces that get filled with cellular debris
• layer of dead cells, proteins and surfactant on the surface of the alveoli
• gaseous exchange is severely compromised

Question 19

symptoms of infant respiratory distress syndrome

Answer 19

breathing difficulties
blue colouration of the baby
apnoea

Question 20

treatment options for infant respiratory distress syndrome

Answer 20

• pre-treatment of the mother with glucocorticoids can enhance surfactant secretion
• 40% oxygen, mechanical ventilation, fluids and artificial surfactants are used for symptoms

Question 21

apnoea vs dyspnoea

Answer 21

apnoea -> stopping breathing
dyspnoea -> difficulty breathing

Question 22

2 types of apnoea

Answer 22

obstructive
Central

Question 23

obstructive apnoea

Answer 23

collapsible airways
narrow airways

Question 24

central apnoea

Answer 24

neurological misfunction/imbalance
no inspiration

Question 25

apnoea

Answer 25

• sleep apnoea common in babies
• prolonged apnoea can impair brain oxygenation
• avoiding sleeping on back, hypnotic drugs, alcohol and respiratory depressants (heroin)

Question 26

type I respiratory failure

Answer 26

• low level of oxygen in the blood (hypoxemia)
• associated with damage to the lung tissue which prevents adequate oxygenation of the blood however the remaining normal lung is still sufficient to excrete carbon dioxide
• low oxygen PO2 <60mmHg but normal or lower PCO2

HIGH O2 THERAPY 85-95%

Question 27

type II respiratory failure

Answer 27

• alveolar ventilation is insufficient to excrete the carbon dioxide being produced
• high PCO2 (hypercapnia)
• respiratory acidosis

low O2 therapy (24-28%)