different inspiratory time

[manberbenitez]

Dear friends:
I want to know your opinion about the IT that you use in different pathologies.In my NICU I have a problem, we have differents kind of patients with RDS, congenital pneumonia, NEC etc etc, that we have to ventilate, but sometimes I found that all my patientes have 0.33 IT ( conventional ventilation) like a rule, no matter what the problem is. In acute phase of an RDS probable we can need short IT like 0.2 - 0.3 sec and we can obtain 3-5 Time constants and get a good ventilation, but what happen with all other patients that sometimes has not respiratory problems, with a good compliance and we can use IT between 0.3 to 0.5 sec. Do we have to ventilate all the neonatal pathology with 0.33 sec or obviously do we have to individualized. Sorry for this question but I have problems with other neonatologist in ventilate a 4kg newborn with 0.33 sc IT or a micropremie 750 grams with the same IT.
thanks in advance for your opinions.

[Dolphine liu]

Dear friends:
I want to know your opinion about the IT that you use in different pathologies.In my NICU I have a problem, we have differents kind of patients with RDS, congenital pneumonia, NEC etc etc, that we have to ventilate, but sometimes I found that all my patientes have 0.33 IT ( conventional ventilation) like a rule, no matter what the problem is. In acute phase of an RDS probable we can need short IT like 0.2 - 0.3 sec and we can obtain 3-5 Time constants and get a good ventilation, but what happen with all other patients that sometimes has not respiratory problems, with a good compliance and we can use IT between 0.3 to 0.5 sec. Do we have to ventilate all the neonatal pathology with 0.33 sec or obviously do we have to individualized. Sorry for this question but I have problems with other neonatologist in ventilate a 4kg newborn with 0.33 sc IT or a micropremie 750 grams with the same IT.
thanks in advance for your opinions.
Dear friend
I have some opinions on your question.
The IT is different with different patients and phrases,therefore IT setting should chang correspondly.
However, the respirtory of neonate is irrregulate,the IT is changing in every breathing cycle. the set IT is just approximate value.
shorten IT setting may cause the shift of PIP and PEEP,and which can be seen from monitor screen. prolonged IT setting may cause respiatory alkalosis.

[Stefan Johansson]

Dear Manuel and Dolphine,
I completely agree with both of you;
1) mechanical ventilation may get somewhat "mechanical"
2) inspiratory time is individual and may change breath by breath

Please have a look at the link below, it explain the lung mechanics in relation to IT well.
http://www.adhb.govt.nz/newborn/TeachingResources/Ventilation/RespiratoryFunctionMonitoringAndGraphics.htm

We tried a Drager babylog 8000 some time ago and if I remember correctly this machine could adjust IT breath by breath. On a term infant we saw that IT ranged up to 0.55 sec.

Manuel, do you use a ventilator, where you could monitor the flow curves, as in the Drager Babylog?

[manberbenitez]

Dear Friends
Thanks for your opinions, and I agree that the IT is totally dynamic with each breath, but we have to put some value in the ventilator. Yes we use floww graphic ventilators and is very intersting to see all the changes that we do, reflect in the real mechanical neonatal world.
thanks in advance. I thanks for the URL.
Manuel