25. basics of mechanical ventilation in neonates

NNC Module: Basics of Mechanical Ventilation in Neonates

Learning Objectives Slide 1

Learning Objectives Learning Objectives (cont.)(cont.)

7. Apply initial ventilator settings.

8. Adjust ventilator settings to improve oxygenation and ventilation as indicated

9. Monitor the neonate during mechanical ventilation.

10. Detect any deterioration during mechanical ventilation and identify its causes.


Learning Objectives Slide 2

Learning Objectives Learning Objectives (cont.)(cont.)

11. Apply paralysis and sedation as needed.

12. Recognize how to wean the neonate from assisted ventilation.

13. Apply physiotherapy and suction to the neonate as indicated.

14. Detect complications that may occur during mechanical ventilation.


Introduction Slide 3

IntroductionIntroduction

Mechanical ventilation is an invasive life-support procedure with many effects on the cardiopulmonary system.

The goal is to optimize both gas exchange and clinical status at minimum FiO2 and ventilator pressure. The ventilator strategy employed to accomplish this goal depends in part on the infant disease process.


Indications of Mechanical Ventilation Slide 4

Indications of Mechanical Indications of Mechanical Ventilation Ventilation

Absolute indicationsAbsolute indications

If any of the following is present:If any of the following is present:

1. Severe hypoxemia with PaO2 less than 50 mmHg despite FiO2 of 0.8.

2. Respiratory acidosis with pH of less than 7.20 to 7.25, or PaCO2 above 60 mmHg.

3. Severe prolonged apnea.


Indications of Mechanical Ventilation Slide 5

Indications of Mechanical Indications of Mechanical Ventilation Ventilation (cont.)(cont.)

Relative indicationsRelative indications1. Frequent intermittent apnea

unresponsive to drug therapy.2. Early treatment when use of mechanical

ventilation is anticipated because of deteriorating gas exchange.

3. Relieving work of breathing in an infant with signs of respiratory difficulty.

4. Initiation of exogenous surfactant therapy in infants with RDS.


Effects of Ventilator Setting Changes on Blood Gases Slide 6

Effects of Ventilator Setting Changes on Effects of Ventilator Setting Changes on Blood GasesBlood Gases

EffectEffectVentilator Ventilator setting setting changeschanges

PaCO2PaCO2 PaO2PaO2

Increase PIPIncrease PIP Decrease Increase

Increase PEEPIncrease PEEP Increase Increase

Increase rateIncrease rate Decrease Increase

Increase I:E Increase I:E ratioratio

------- Increase

Increase FiO2Increase FiO2 ------- Increase

Increase flowIncrease flow Decrease Increase


Starting Ventilator Setting Slide 7

Starting Ventilator Starting Ventilator SettingSetting

Intubate infant with an endotracheal tube according to body weight.

During intubation, infants require fractional inspired oxygen FiO2 that is 10% higher than what they were receiving before mechanical ventilation.


Guidelines for Endotracheal Tube Size Slide 8

Guidelines for Endotracheal Guidelines for Endotracheal Tube SizeTube Size

Infant weight(gm)Infant weight(gm) Endotracheal tube Endotracheal tube internal diameterinternal diameter

< 1,000gm 2.5mm

1,000 - 2,000 3.0mm

2,000 - 3,000 3.5mm

> 3,000 3.5 - 4.00mm


Initial Setting of Mechanical Ventilation Slide 9

Initial Setting of Mechanical Initial Setting of Mechanical VentilationVentilation

PIP is determined by hearing good breath sounds and good lung expansion.

FiO2 is determined according to patient need.

Ti should not be prolonged because of risk of alveolar over-distention. Start with 0.25 seconds and do not exceed 0.5 seconds (unless there are special indications).

Respirator rate should not ordinarily exceed 80 breaths/min to allow sufficient time for exhalation.


Initial Setting of Mechanical Ventilation Slide 10

Initial Setting of Mechanical Initial Setting of Mechanical Ventilation (cont.)Ventilation (cont.)

Initial settingsInitial settings

Fio2Fio2 As indicatedAs indicated

Systemic flowSystemic flow 8-10l/min8-10l/min

RateRate 60 breaths / min60 breaths / min

Ti/TeTi/Te 1:1.25 - 1:41:1.25 - 1:4

PIPPIP 18 - 22cm H2018 - 22cm H20

Good breath Good breath soundssounds

PEEPPEEP 3 - 5cm H203 - 5cm H20


Subsequent Settings of Mechanical Ventilation Slide 11

Subsequent Settings of Subsequent Settings of Mechanical VentilationMechanical Ventilation

Measure arterial blood gases half an hour after the initial setting and adjust the setting accordingly. (Table)

Although it is tempting to try to lower PaCO2 by increasing the respiratory rate rather than by adjusting ventilatory pressure, data suggest that this can not be without risk.


Subsequent Settings of Mechanical Ventilation Slide 12

Subsequent Settings of Mechanical Subsequent Settings of Mechanical VentilationVentilation (cont.) (cont.)

Subsequent Subsequent settingssettings

PEEPPEEP PIPPIP

Low PaO2 ,Low PaO2 ,

Low PaCo2Low PaCo2Increase

Low PaO2 ,Low PaO2 ,

High PaCo2High PaCo2Increase

High PaO2 ,High PaO2 ,

High PaCo2High PaCo2Decrease

High PaO2 ,High PaO2 ,

Low PaCo2Low PaCo2Decrease


Monitoring The Infant during Mechanical Ventilation Slide 13

Monitoring The Infant Monitoring The Infant during Mechanical during Mechanical

VentilationVentilation Obtain an initial blood gas within 15-30

minutes of starting mechanical ventilation.• Obtain a blood gas within 15-30 minutes of Obtain a blood gas within 15-30 minutes of

any change in ventilator settings. any change in ventilator settings.

• Obtain a blood gas every 6 hours unless a Obtain a blood gas every 6 hours unless a sudden change in the infant's condition sudden change in the infant's condition occurs. occurs.

• Continuous monitoring of the O2 saturation Continuous monitoring of the O2 saturation

level as well as the HR and RR is necessary.level as well as the HR and RR is necessary.


Deterioration during Mechanical Ventilation Slide 14

Deterioration during Deterioration during Mechanical VentilationMechanical Ventilation

Sudden clinical deteriorationSudden clinical deterioration Mechanical or electrical ventilator

failure. Disconnected tube or leaking

connection. Endotracheal tube displacement or

blockage. Pneumothorax.


Deterioration during Mechanical Ventilation Slide 15

Deterioration during Deterioration during Mechanical VentilationMechanical Ventilation

(cont.)(cont.)Gradual deteriorationGradual deterioration Inappropriate ventilator setting. Intraventricular hemorrhage. Baby fighting against ventilator. PDA. Anemia. Infection.


Paralysis and Sedation Slide 16

Paralysis and Sedation Paralysis and Sedation (cont.)(cont.)

Sedation is useful when agitation interferes with ventilatory support and when infants fight the ventilator.

Phenobarbital decreases the variability in mean arterial pressure and intracranial pressure associated with endotracheal suctioning.


Weaning Slide 17

WeaningWeaning When the patient is stable, FiO2 and PIP

are weaned first. Decrease PIP as tolerated and as chest rise

diminishes. When PIP is around 20, attention is

directed to FiO2 and then to the respiratory rate alternating with each other, in response to assessment of chest excursion, blood gas results, and oxygen saturation.


Weaning Slide 18

Weaning Weaning (cont.)(cont.) As frequency is decreased, Te should

be prolonged. For larger infants, weaning to

endotracheal CPAP may begin when PIP has been stable between 15-18 cmH2O, and FiO2 is less than 0.4.

The infant can be weaned to oxygen hood when he/she requires less than 4 cmH2O of end expiratory pressure.


Weaning Slide 19

Weaning Weaning (cont.)(cont.) For infants weighing less than 1,750 gm,

when PIP is less than 15 cmH2O and FiO2 is less than 0.3, start to decrease the respiratory rate gradually to 15-20 breaths/min and then wean directly to nasal CPAP if available.

In most infants, when ventilator frequency of approximately 15 breaths per minute is tolerated, endotracheal CPAP may be tried for a short period before extubation.


Weaning Slide 20

Weaning Weaning (cont.)(cont.) Atelectasis after extubation is common in

preterm infants recovering from RDS. Use of nasal CPAP may prevent atelectasis.

Steroids are not routine before extubation, but if there was prolonged intubation or previous failed attempts of extubation, a short course of steroids may facilitate extubation.

If strider caused by laryngeal edema develops after extubation, racemic epinephrine aerosols and steroids may be helpful.


Physiotherapy and Suctioning Slide 21

Physiotherapy and Physiotherapy and SuctioningSuctioning

Tracheal suctioning and chest physiotherapy should be minimized in infants with HMD in the first few days after birth because their secretions are scant.

Physiotherapy and suctioning should be done to prevent the development of atelectasis, especially in premature infants. However, some infants show acute deterioration of blood gases.


Complications of Mechanical Ventilation Slide 22

Complications of Mechanical Complications of Mechanical VentilationVentilation

Endotracheal tube complications Endotracheal tube complications and and

tracheal lesionstracheal lesions Accidental displacement of the

endotracheal tube into main stem bronchus, hypopharynx, or esophagus.

Accidental extubation. Obstruction of endotracheal tube.



Complications of Complications of Mechanical Ventilation Mechanical Ventilation

(cont.) (cont.) Airway injuryAirway injury Subglottic stenosis. Edema of the cords after extubation

(may result in hoarseness and stridor). Prolonged use of orotracheal

intubation associated with palatal groove formation.

Necrotizing tracheobronchitis.




(cont.)(cont.)

InfectionInfectionPneumonia and systemic infections with Staphylococcus epidermidis, Candida organism, gram-negative organisms, and Staphylococcus aureus.




(cont.)(cont.)Chronic lung disease / Oxygen Chronic lung disease / Oxygen

toxicitytoxicity Bronchopulmonary dysplasia (BPD),

related to increased airway pressure and changes in lung volume.

Other contributing factors are oxygen toxicity, anatomic and physiologic immaturity, and individual susceptibility.




(cont.)(cont.)Air leakAir leakPneumothorax, pulmonary interstitial emphysema (PIE), and pneumomediastinum directly related to increased airway pressure occurring frequently at MAP >14 cmH2O.




(cont.)(cont.)MiscellaneousMiscellaneous Intraventricular hemorrhage. Decreased cardiac output. Feeding intolerance

25. basics of mechanical ventilation in neonates

Technology