pediatric emergency medicines

1. 1
Mechanical Ventilation – II
(Troubleshooting and Weaning)

2. 2
By the end of this session, the learners will be
able to:
1. Enlist common ventilator alarms
2. Recognize and outline the troubleshooting of
common alarms and problems
3. Discuss weaning from mechanical ventilation
Objectives

3. 3
Ventilator Alarms
Always treat your patient first and the ventilator
second!
Examine patient and measure vital signs
Review the alarm and ventilator parameters
Try to find out the cause of the alarm: Patient
or Ventilator ??

4. DOPE
• D: Displacement
• O: Obstruction
• P: Pneumothorax
• E: Equipment failure
4

5. 5
Ventilator Alarms
• Knowledge of various alarms and timely response
is very crucial
• Most ventilators have audible and visual alarms
 alarm (low priority) for warning
 alarm (high priority) Immediate action!!!

6. 6
Common Ventilator Alarms
• High airway pressure alarm
• Low airway pressure alarm
• High minute volume
• Low minute volume
• Apnoea alarm
• Low Oxygen pressure alarm
• System failure alarm

7. Alarm setting for 5 years, 20 kg, pneumonia patient
in SIMV mode
Initial setting Lower limit Upper limit
PIP 25 20 30
TV 120 ml 80 160
PEEP 8 6 10
RR 30 20 40
FiO2 80% 70 90
7

8. 8
Airway pressure alarm
Airway
pressure
< 10 cmH20
Low Pressure
Alarm
>30 cmH20
High Pressure
Alarm

9. Causes of high pressure alarm
Patient factors:
 Coughing
 Biting the tube
 Bronchospasm
 ARDS
 Pneumothorax
Ventilator factors:
 Faulty Settings
 Patient Ventilator
 Asynchrony
Circuit and ET tube factors:
 Kinking of circuit
 Water in the circuit
 Kinking of ET tube
 Secretion in tube
 Mucus plug in ET tube
 Endo-bronchial
position of ET tube
9

10. 10
Troubleshooting high pressure alarm
Examine the patient
•Bite guard
•Sedation
•Bronchodilator
•Rule out Pneumothorax
Check the Circuit
•Remove kinks
•Drain water

11. 11
Troubleshooting high pressure alarm
Check the ET tube
• Remove kinks
• Check marking Endobronchial displacement
 pull and adjust the tube
• Pass a suction catheter through the tube 
remove mucus/secretions
• Manual ventilation with Bag Difficulty 
Block change the tube
Check the Ventilator
•Check settings
•Measure airway pressure (Plateau pressure)

12. 12
Causes of low pressure alarm
Circuit factors:
 Circuit disconnection
 Loose circuit connection
 Leak from water trap
 Loose humidifier connection
ET tube factors:
 Cuff leak (ET tube or Tracheostomy tube)
 ET tube pulled out
Patient factors:
 Insufficient inspiratory flow
 Leak from chest tube

13. 13
Troubleshooting low pressure alarm
Check Disconnections or Loose Connections
Check cuff leak
Check Ventilator
settings
Ensure adequate Inspiratory flow
Whenever in Doubt:
CALL FOR HELP &
MANUALLY VENTILATE THE PATIENT

14. 14
Apnoea alarm
Ventilator does not sense a breath during set interval (20
seconds)
Causes:
 Over sedation, or neurologic changes
 No respiratory effort in spontaneous mode
 Inappropriate alarm settings
 Cardiopulmonary arrest
• Rule out life threatening causes
• Make sure Apnoea-backup-Ventilation is ON
• Review settings
• Whenever in doubt manually ventilate the patient

15. 15
Low O2 Inlet Pressure
• Inadequate or Loss of oxygen inlet pressure
• Call the maintenance service:
• To restore the pressure OR
• To connect new oxygen cylinder
• Monitor patient and manually ventilate with 100%
oxygen from cylinder

16. 16
Clinical Problems: Fighting the Ventilator

17. 17
Fighting the Ventilator
• Biting the tube
• Asynchrony
• Bronchospasm, Pneumothorax
• Inadequate Sedation & Analgesia
Patient
Factors
• Leaks, disconnections, kinking,
blockade, secretions
• Increased dead space
Circuit
factors
• Inappropriate settings
• Inadequate flow
Ventilator
factors
Identify and treat the cause

18. 18
Accidental Extubation
Call for HELP
Manually ventilate with Bag and Mask
• Ensure the bag is attached to the oxygen
source with 15 L/min flow
• Ensure a good seal on the patient’s face
• Maintain Oxygenation
• Prepare for re-intubation

19. 19
Weaning from Mechanical
Ventilation

20. 20
Weaning from Mechanical Ventilation
“Weaning is the process of decreasing ventilator
support and allowing patients to maintain their
ventilation”
Weaning is usually started once:
 Primary Cause for mechanical Ventilation has been
resolved or Controlled

21. 21
Weaning from Mechanical Ventilation
AC CPAP
SIMV
PSV

22. Assessing readiness to wean
• Clinical assessment
• Objective assessment
Hemodynamic stability
Adequate oxygenation
Adequate ventilation
Adequate mentation
22

23. 23
Mechanical ventilation
1. Appropriate level of oxygenation
2. Adequate ventilatory status
3. Absence of major organ failure
4. Intact airway protective mechanism
SBT
30-120 minutes
SBT passed
Yes
No
Extubation
Continue PS/Assist mode
Decrease PS by 2 cm
every 12 hourly
24 hrs
Low level CPAP (5 cm H2O
Pressure support ventilation (5-
7 cm H2O
T-piece breathing
SBT failure
Subjective criteria:
Diaphoresis
Nasal flaring
Agitation
Anxiety
Objective criteria:
Tachypnoea
Tachycardia
Hypotension
Hypoxaemia/Acidosis
Arrhythmia

24. 24

25. Summary
• What are the common ventilator alarms?
• What is DOPE?
• What is the immediate step in troubleshooting of
ventilator whenever you are in doubt?
• How do you assess patient for readiness to wean on
mechanical ventilator?
25

26. 26
Thank You