Register for email alerts and news feeds:
This journal | BMJ Group
rss
Archives of Disease in Childhood - Fetal and Neonatal Edition 2000;82:F237-F242; doi:10.1136/fn.82.3.F237
Copyright © 2000 BMJ Publishing Group Ltd & Royal College of Paediatrics and Child Health.
Arch Dis Child Fetal Neonatal Ed 2000;82:F237-F242 ( May )

Effect of changes in oscillatory amplitude on PaCO2 and PaO2 during high frequency oscillatory ventilation

C Morgan, P R F Dear, S J Newell

Neonatal Intensive Care Unit, St James' University Hospital, Beckett Street, Leeds LS9 7TF, UK

Correspondence to: Dr Morgan, Neonatal Intensive Care Unit, Royal Free Hospital, Pond Street, Hampstead, London NW3 2QG, UK email: newells{at}sjuhnnu.demon.co.uk

Accepted 10 December 1999

AIMS---To describe the relation between oscillatory amplitude changes and arterial blood gas (ABG) changes in preterm infants receiving high frequency oscillatory ventilation, using a multiparameter intra-arterial sensor (MPIAS).
METHODS---Continuous MPIAS ABG data were collected after amplitude changes and stratified according to FIO2: high (> 0.4) or low (< 0.3). For each amplitude change, the maximum change (from baseline) in PaCO2 and PaO2 over the following 30 minutes was determined. In total, 64 oscillatory amplitude changes were measured in 21 infants (median birth weight 1040 g; gestation 27 weeks).
RESULTS---All amplitude increases produced PaCO2 falls (median -0.98 and -1.13 kPa for high and low FIO2 groups respectively). All amplitude decreases produced PaCO2 rises (median +0.94 and +1.24 kPa for high and low FIO2 groups respectively). About 95% of the change in PaCO2 was completed in 30 minutes. Amplitude changes did not affect PaO2 when FIO2 > 0.4. When FIO2 < 0.3, amplitude increases produced a PaO2 rise (median = +1.1 kPa; P < 0.001) and amplitude decreases a fall (median = -1.2 kPa; P < 0.001).
CONCLUSIONS---After oscillatory amplitude changes, the speed but not the magnitude of the PaCO2 change is predictable, and a rapid PaO2 change accompanies the PaCO2 change in infants with mild lung disease and a low FIO2.


Key messages

  • A 3 cm H2O change in oscillatory amplitude results in a median change in PaCO2 of about 1.0 kPa (but the range of effect is wide)
  • Following changes in oscillatory amplitude:
  • the speed and direction of change in PaCO2 is predictable;
  • about 95% of the change in PaCO2 is completed within 30 minutes;
  • PaO2 is unaffected if lung disease is severe;
  • if lung disease is mild/improving, rapid changes in PaO2 occur (up to 4.7 kPa)




Keywords: arterial; blood gas monitoring; lung; oscillatory amplitude; prematurity; ventilation

© 2000 by Archives of Disease in Childhood
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?

This article has been cited by other articles:

  • Morley, C J, Lau, R, De Paoli, A, Davis, P G (2005). Nasal continuous positive airway pressure: does bubbling improve gas exchange?. Arch. Dis. Child. Fetal Neonatal Ed. 90: F343-f344 [Abstract] [Full Text]  

This Article

Services
Citing Articles
Google Scholar
PubMed
Topic Collections
Bookmark with

Register for free content

The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.

Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.

Latest from ADC

 

ADC is co-owned by the RCPCH and is the official journal of the European Academy of Paediatrics

BMJ Careers - Latest Paediatrics and Paediatric Surgery Jobs

Paediatrics and Paediatric Surgery Jobs

Show me all >>