Lecture 5 Part 2

Question 1

*List the stages of the development of the respiratory structure and the weeks of their development

Answer 1

Embryonic - 0 to 7

pseudoglandular 7 to 17

canalicular 17 to 27

saccular 27 to 36

alveolar 36 to 2 years

Question 2

• what respiratory complications can happen during to prematurity?*

Answer 2

Respiratory distress syndrome (RDS)

Apnoea of prematurity

Bronchopulmonary dysplasia

Question 3

For RDS, hyaline membrane disease can happen. What can this lead to?

Answer 3

Alveolar damage - formation of exudate from leaky capillaries inflammation, inflammation, repair

Primary and secondary pathology - surfactant deficiency and structural immaturity

Question 4

How common is hyaline membrane disease?

Answer 4

75% of infants born before 29 weeks
10% in infants born after 32 weeks

Question 5

What is the clinical features of RDS?

Answer 5

Respiratory distress
Tachypnoea - grunting, intercostal recessions, nasal flaring, cyanosis
Worsens over minutes to hours
Natural history

Question 6

How is RDS managed?

Answer 6

Maternal steroids

Surfactant

Ventilation - invasive, non invasive ventilation

Question 7

What are the goals of respiratory support?

Answer 7

Maintain oxygenation

Effective ventilation

Minimise work of breathing

Avoid complications- short and long term

Question 8

Why is it important to control oxygenation?

Answer 8

To improve the oxygen in the lungs
Have enough space for oxygen to diffuse into the blood
Blood flows through alveolar capillaries

Question 9

What happens to the oxygen control when a baby is hypoxic?

Answer 9

Increase the FiO2
Open the lungs: PEEP or CPAP or mean airway pressure
Improve blood flow in lungs: volume,BP, NO

Question 10

What happens when you control the CO2?

Answer 10

Move gas in and out of the lung to remove CO2
Controlled by - tidal volume, ventilator rate/spontaneous rate, assisting baby’s breathing
Treatment if hyper and hypo carbia - alter tidal volume, alter ventilator rate

Question 11

What are the disadvantages of frequent ventilator alarms?

Answer 11

Disruption to staff
Staff desensitised
Potential threat for patient safety
Parental anxiety
High priority alarms often exceed safe acoustic limits

Question 12

What are the ventilator alarm hazards?

Answer 12

Inappropriate modification of alarms
Alarms desensitised or alarm fatigue
Non restoration of alarms settings to the normal or standard value after being modified for specific situation
Improper relaying of alarm signals to appropriate personnel

Question 13

What are the non invasive methods for neonatal respiration?

Answer 13

Nasal cannula - blended oxygen delivered through prongs in the nose at low flow rates
HFNC/HFOT - humidified, blended oxygen delivered through prongs in the nose at higher flow rates
CPAP - humidified, blended oxygen driven by CPAP to prevent alveolar collapse. Delivered through prongs in the nose or by mask
BiPAP: Biphasic CPAP
NIPPV
NIV NAVA: Neural adjustment ventilatory assist

Question 14

What is the invasive way for neonatal respiratory care?

Answer 14

Mechanical ventilation

Question 15

What are the hybrid way for respiratory care of neonates?

Answer 15

SIMV/SIPPV + VG
PSV + VG
SIMV + PS

Question 16

Explain the chain for mechanical ventilation

Answer 16

Mechanical ventilation splits to positive and negative and then positive splits to conventional ventilator and high frequency ventilation

Question 17

What parameters can ventilators accurately measure?

Answer 17

Inspired tidal volume
Expired tidal volume
Endotracheal tube leak
Inflation, inspiration, expiration times and pressures

Question 18

Why 3 types of high frequency ventilation can you get? What happens in them?

Answer 18

High frequency oscillatory ventilation (HFOV) - technique generates active biphasic displacement of air during both inspiration and expiration

High frequency flow interruption (HFFI) - short bursts of gas delivered directly into the ventilatory circuit

High frequency jet ventilation - rapid pulses fresh gas produced by a pinch valve and released as a jet, either directly into the upper airway via a special endotracheal tube or into the Y piece of the circuit

Question 19

What should the setting of ventilators be set to?

Answer 19

It should be individualised based on the pathoohysiologic characteristics and severity of the underlying lung disease