SLEEP PHYSIOLOGY

Question 1

An apnoea is classed by:

Answer 1

Complete cessation of breathing (>90%) resp efforts continue. >10 SECONDS

Question 2

CSA (CENTRAL SLEEP APNOEA) IS…

Answer 2

When there is no respiratory drive and effort.

Question 3

A pulse rate rise of how much may indicate cortisol arousal/sleep disturbance.

Answer 3

> 6bpm

Question 4

What is NIV?

Answer 4

Non-invasive ventilation, uses masks instead if endotracheal tube

Question 5

IPAP is…

Answer 5

• inspiratory positive airway pressure- inflates the lungs
• Higher the Ipap higher the Vt, >10cmh20 is ideal
• Stiff/fibrotic lungs may need more

Question 6

EPAP is…

Answer 6

expiratory positive airway pressure- stents upper airway open

• Higher epap in obese patients,
• set at least 4cmH20 to help flush c02

Question 7

Describe intrinsic peep

Answer 7

• Typical in COPD patients, airway collapse hence air trapping
• Increased lung volumes. FRC increases.
• Inspiratory muscles need to contract behind air trapping to start inspiratory flow
• EPAP should be increased to help this.

Question 8

How can patients be assessed before, during and after NIV

Answer 8

ABG- GOLD STANDARD,

• CBG- CAN BE ACCURATE, EASY TO PERFORM, LESS PAINFUL THAN ABG
• TOSCA,TcCO2 GIVES OVERNIGHT TcC02 and Sp02 and trends

Question 9

WILL those who have kyphoscoliosis need a higher pressure? And please give your reasoning.

Answer 9

stiff lungs-higher pressures needed to expand the chest walls (around 20-25cmH2O)

Question 10

Will those who have a neuromuscular condition need a higher or lower pressures than those who have kyphoscoliosis?

Answer 10

Neuromuscular conditions= lower pressures (12-15cmH20)

Question 11

The pros of NIV are:

Answer 11

• increase ventilation
• reduce PC02
• Saves endotracheal intubation
• saves ITU resources

Question 12

The cons of NIV are:

Answer 12

• leaking
• pressure points, discomfort
• barotrauma to the lungs if high pressures applied which could lead to pneumothorax
• prolonging disease

Question 13

Why paeds sleep centres?

Answer 13

Importance of early diagnosis and treatment. Increased risk of adult mortality and cost of treatmen if undiagnosed and untreated. ‘

Question 14

In infants who sleep 12-16 hours, the percentageof REM vs nREM 3 is:

Answer 14

Around 50% REM Vs nREM3 50%

Question 15

The N REM vs REM in teenagers/adults is:

Answer 15

8 Hrs Sleep: 75 nREM vs 25% REM

Question 16

The main Paeds physiology features are:

Answer 16

Smaller space, larger tongue and epiglottis

Narrow nares. Larynx is funnel shaped

Question 17

Upper airway patency is determined by-

Answer 17

Activity of upper airway muscle
@Genioglossus-tongue
@tensor veli  plating- soft palate
-craniofacial and soft tissue structure
-sleep stage

Question 18

What happens to the upper airway during sleep?

Answer 18

Decreased uaw muscle tone
-decreased UAW reflex responses to negative airway pressure
-decreased airway volume
All leading to uaw collapse, snore, uaw obstruction during sleep.

Question 19

How is the chestwall And diaphragm different than adults?

Answer 19

. Ribs are more cartilaginous and therefore chest wall is more compliant

• during the first two years ribs are more horizontal which limits thoracic expansion
• infants are dependant on diaphragm for inspiratory and expiratory phase.

Question 20

What is the respiration pattern in pediatrics

Answer 20

paradoxical inward chest wall movement during inspiration

Question 21

Does respiration increaseor decrease with age?

Answer 21

rate decreases with age-

40-60br.min, higher in REM infancy

Question 22

Is periodic breathing common in preterm infants and in what sleepstage does it occur in?

Answer 22

‘Common in preterm infants. Occurs in all sleep stages, but more common in REM.

Question 23

How is an apnoea scored in paeds?

Answer 23

,, Apnoeas are scored the same as adults with the addition of 2 missed breaths.

Question 24

Central apnoeas are classed as… w

Answer 24

90% in flow signal and absent inspiratory effort. Must last >20s
Or- a >%o2 desat with atleast 2 missed breaths.
For infants <1 year-decreased Hr, <50bpm for atleast 5 seconds or<60bpm for 15 seconds.

Question 25

Mixed apneas are classed as

Answer 25

> 2 missed breaths and >90% fall in flow signal

Question 26

Hypopnea in Paediatric isclassed as:

Answer 26

2 missed breaths with >30% o2 desat,

. If there’s snoring, flattening in flow or paradox =obstructive /Opposite =central

Question 27

Periodic breathing is when…

Answer 27

> 3 episodes of central pauses in respiration(no airflow or inspiratory effort) lasting>3s separated by no more than 20s of normal breathing.

Question 28

Hypoventilation is when

Answer 28

25%TST Spent with c02 50mmHg(6.7kPa)- can be REM related

Question 29

-, what is considered a Normal Spo2 %? And a normal ODI is…

Answer 29

Greater than 95 %, 92-88% is the lower limit of Normal. And an ODI of 0-4 is normal

Question 30

Normal Tc02 levels are:

Answer 30

35mmhg- 45,>50 is abnormal and 55mmHg should be the highest

Question 31

Normal AHI FOR OSA ahi that includes mixed EVENTS ARE

Answer 31

<1=normal, 1-5=mild, 5-10=moderate,>10=severe

Question 32

Define nocturnal hypoventilation

Answer 32

Ineffective breathing/’under’ breathing
-Respiratory depression
-Inability to effectively undertake gas exchange
•Hypercapnia
Typically secondary to an underlying diagnosis

Question 33

Which diagnostic tests can be used to diagnose nocturnal hypoventilation

Answer 33

Overnight oximetry
TOSCA-TC02
ABG/CBG

Sitting and supine vc

Question 34

In Which disease conditions would you typically have Nocturnal hypoventilation

Answer 34

OHS- UAO, REDUCED COMPLIANCE, EARLY AIRWAY CLOSURE , reduced Vc and hypercapnic,hypoxia ventilators response

COPD- INTRINSIC PEEP, HYPERINFLATION, reduced Vt expansion and functional diaphragm weakness

NMD-UAO, REDUCED VC AND Vt

Cwd- reduced compliance, low VC AND Vt

Question 35

How can nocturnal ventilation be treated

Answer 35

CPAP
NIV
SURGICAL
LTOT