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Respiratory Failure & Mechanical Ventilation

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69 years old with anoxic encephalopathy and acute right parietal infarct after cardiac arrest. On Volume control mode of ventilation with VT of 510 breathing

What do you think?

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62 years old female who was intubated for acute on chronic hypercapnic respiratory failure secondary to COPD exacerbation. Her ideal body weight is 67 Kg. CXR shows severely hyperinflated lungs.

Patient was placed on AC mode of ventilation with VT of 450 mL, RR of 22 per minute, and an inspiratory flow of 60 L/min. Her minute ventilation was 10 liters per minute.

Ibrahim Ameen
ي ا

I guess all the answers are right, the goal is to prolong the expiratory time to allow for complete exhalation of the air. I would start by increasing the flow rate trying to decrease the inspiratory time and I:E ratio without changing the minute ventilation. Then I would decrease the tidal volume and/or the rate and accepting permissive hypercapnea. Adding external PERP can help triggering on the ventilator as this would allow the patient to exert less efforts.

This screenshot shows an increased flow rate to 70 L/min, decreased rate to 14, and decreased tidal volume to 450:

inspiratory hold now shows improved plateau pressure to 22:

And expiratory hold shows improved autoPEEP to around 5-7:

Blood gases improved despite decreased minutes ventilation:


‎‏Age/gender : 54y/o male

📝 ‎‏ Diagnosed as ARDS, H1N1 positive, later found to have ICH

‎‏ 🗂️ Medical history : Nil

🏋🏻‍♂️ ‎‏Adm wt.60kg, ht.168cm.

‎‏ Current wt: 54.0

Ibrahim Ameen

Interesting answers, it looks like this is a case of delayed cycling indicated by increase inspiratory flow at end of inspiration in every single breath. Notice the increase in volume at the same time. This may lead to double triggering if the inspiratory negative pressure continued and was at the level to trigger another breath. However, we need to rule out reverse triggering by applying expiratory hold and notice if these efforts disappear. If they disappear then the answer to the question would be resuming paralysis, if they did not then we need to shorten inspiratory time on the ventilator first and re-evaluate.


67 year old who eas intubated and placed on the ventilator for COPD exacerbation. Respiratory rate increased from 13 to 142 per minute

What should you do?

Ibrahim Ameen
Salman Ali

Thank you all for your answers, this is auto cycling due to low sensitivity responding to heart pulsation.


64 years old male who is a heavy smoker with COPD and laryngeal carcinoma, s/p tracheostomy. He is addmitted now to the ICU complaining of air hunger. When connected to the ventilator; it showed the waves you see and the patient felt suffocation. Unfortunately, this is the only screenshot that was provided by Dr. Abdulhaseeb Tarabulsi.

Knowing that this is not a ventilator malfunction or circuit disconnection, what do you thing is happening?


With this huge leak, I think tracheo-bronchial fistula is very likely and should be investigated


Suction me please!

Ahmed Argawi
Faisal Rawagah
Ibrahim Ameen
suray Bakkar

Water in circut


Ventilator graphic of an intubated asthmatic patient on mechanical ventilation showing mild persistent flow at end of expiration indicating auto-PEEP:

The ventilator settings were changed as the following:

VT decreased from 470 to 420 mL.

Rate decreased from 20 to 16 breaths per minute but the patient is still breathing over.

The inspiratory time was decreased from 0.9 second to 0.6 second.

Noor Shah
Noor Shah

Improving in auto PEEP , it can be achieved by :

1) decrease in RR ,

2) decrease in Tidal Volume,

3) by decreasing inspiration time, expiration time will be automatically increased.


How do you explain the the drop in the pressure indicated by the white arrows on the pressure/time scalar?


Please answer the question and provide your input in the comment section!

The drop in the pressure on the pressure waveform is caused by:

  • 0%Ventilator malfunction

  • 0%Double triggering

  • 0%Patient’s inspiratory efforts

  • 0%Early cycling


having this phenomena in each breath at the same time will trigger me to find if it is a type of reverse trigger or just additional inspiratory efforts that do not cause another trigger.

the scalar does not show if the initiation of the cycle is triggered by time or by the patient.

Reverse trigger may manifest by a nigative deviation in the pressure wave after the beginning of the inspiration by the ventilator. However, the initial trigger should be time.

I tried to compare the total frequency to the set frequency. They are not the same, 41 vs 24, which may indicate that its not time triggered but patient triggered. If this is true then it is not a reverse trigger.


PRVC mode of ventilation with a targeted VT of 400, RR 26 and I:E ratio of 1:1.5. Notice the dynamic hyperinflation (autoPEEP) with persistent flow at end of expiration and the ineffective triggers.

Ventilator settings were adjusted to allow longer expiration by decreasing the rate to 20 per minute, and decreasing inspiratory time with I:E at 1:2.9. The volume was also increased to 450 ml.

Dynamic hyperinflation improved remarkably and now the ventilator is triggered with every inspiratory effort of the patient.

Ibrahim Ameen
Hussam Almasri
Osama BasHa
Noor Shah
Noor Shah

In the first setting of ventilator, there were two issues discovered

1) Auto Peep due to low expiration time, leading to air trapping- Auto Peep, by decreasing RR expiration time increased lead to resolved the auto peep issue as shown in second picture.

2) The second issue discovered what I observed was “ Air Hunger or Starvation ” in flow time waves, which was resolved by increasing Tidal Volume or Peak flow.

Thanks Dr. Mazen for sharing such interesting articles.