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The influence of physiotherapy and suction on respiratory deadspace in ventilated children

Eleanor Main1, Janet Stocks

  • 1Centre for Nursing and Allied Health Professionals Research and Physiotherapy Department, Institute of Child Health, 7th Floor, Old Building, Great Ormond Street Hospital for Children NHS Trust, Great Ormond Street, London WCIN 3JH, UK. maine@gosh.nhs.uk

Intensive Care Medicine
|May 13, 2004
PubMed

Insights

Respiratory physiotherapy significantly increased physiological and alveolar deadspace in ventilated children, unlike suction. These deadspace measures may better reflect gas exchange changes than carbon dioxide levels.

Area of Science:

  • Pediatric critical care medicine
  • Respiratory physiology
  • Mechanical ventilation

Background:

  • Ventilated infants and children often require airway clearance techniques.
  • Respiratory physiotherapy and suction are common interventions, but their comparative effects on gas exchange are not fully understood.

Purpose of the Study:

  • To compare the effects of respiratory physiotherapy and suction on deadspace volumes.
  • To assess impacts on carbon dioxide elimination (VCO(2)), end-tidal CO(2) (ETCO(2)), and arterial partial pressure of CO(2) (PaCO(2)) in ventilated pediatric patients.

Main Methods:

  • A randomized crossover study involving 81 fully ventilated children.
  • Participants received both respiratory physiotherapy and suction with a washout period.
  • Gas exchange parameters, including deadspace volumes, were measured using a respiratory monitor.

Main Results:

  • Respiratory physiotherapy led to significant increases in physiological deadspace (VD(phys))/kg and alveolar deadspace (VD(alv))/kg.
  • Suction did not produce significant changes in these deadspace measures.
  • Significant differences were observed between the two interventions in VD(phys)/kg, VD(alv)/kg, expired tidal volumes (V(TE)), mixed expired CO(2) (PeCO(2)), and ETCO(2).

Conclusions:

  • Differences in technique likely explain the distinct effects of physiotherapy and suction on deadspace.
  • Physiological and alveolar deadspace may be more sensitive indicators of subtle gas exchange and ventilation changes than VCO(2) or PaCO(2).
  • Interpreting deadspace changes requires concurrent analysis of related parameters.
Abstract

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