Skip to main content
SpringerLink
Log in

The mechanics of breathing in children with acute severe croup

Intensive Care Medicine volume 34, pages 324–332 (2008)Cite this article

Abstract

Rationale

The assessment of the severity of croup and response to therapy has remained a clinical one. Despite recognition of the importance of a reproducible and easily applicable method for objectively measuring severity, currently, no such technique exists.

Objectives

We postulated that measurements of air flow and intrathoracic pressure changes in patients with severe croup would provide detailed information about the mechanics of breathing and the potential for the development of continuous bedside methods for objective monitoring of upper airway obstruction.

Methods

Twenty out of 21 eligible infants and children with severe upper airway obstruction from croup, and 5 control participants, were studied under light sedation utilizing face masks and nasogastric feeding tubes for flow and esophageal pressure measurements.

Measurements and main results

Children with croup had lower tidal volumes, but breathed faster, thus maintaining similar minute volumes to the controls. During inspiration, all but 2 croup patients (but no controls) displayed flow limitation. Area within the flow–volume curve was significantly decreased and minute ventilation for effort expended was nearly 4.5 times higher in croup patients than in controls. Peak-to-trough pleural pressure swings, pressure–rate product and pressure–time integral were also significantly higher than in controls (p < 0.001) and returned to the normal range in the 9 patients who were subsequently intubated (p < 0.001).

Conclusions

Patients with severe croup maintain minute ventilation by means of huge increases in intrathoracic pressure changes. Inspiratory flow limitation is present. In future outcome studies, measurements of respiratory function that do not include intrathoracic pressure changes are unlikely to be effective measures of the severity of croup.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

USD 39.95

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Fig. 1
Fig. 2
Fig. 3

References

  1. Berman S (1991) Epidemiology of acute respiratory infections in children of developing countries. Rev Infect Dis [Suppl] 13(6):S454–S462

    Google Scholar 

  2. Szpunar J, Glowacki J, Laskowski A, Miszke A (1971) Fibrinous laryngotracheobronchitis in children. Arch Otolaryngol 93:173–178

    PubMed  CAS  Google Scholar 

  3. Newth CJL, Levison H, Bryan AC (1972) The respiratory status of children with croup. J Pediatr 81:1068–1073

    Article  PubMed  CAS  Google Scholar 

  4. Wesley AG, Bruce R, Holloway R (1968) Arterial blood gases as a guide to management of infective croup. S Afr Med J 42:1237–1239

    PubMed  CAS  Google Scholar 

  5. Wesley AG (1974) Interpretation of arterial carbon dioxide tension in laryngotracheobronchitis. S Afr Med J 48:1152–1154

    PubMed  CAS  Google Scholar 

  6. Ingelstedt S, Jonson B, Tibbling L (1966) Respiratory mechanics in normal children and in children with pseudocroup. Acta Otolaryngol Suppl 224:437–441

    Google Scholar 

  7. Couriel JM, Hibbert M, Olinsky A (1984) Assessment of proximal airway obstruction in children by analysis of flow-volume loops. Br J Dis Chest 78:36–44

    Article  PubMed  CAS  Google Scholar 

  8. Sivan Y, Deakers TW, Newth CJL (1990) Thoracoabdominal asynchrony in acute upper airway obstruction in small children. Am Rev Respir Dis 142:540–544

    PubMed  CAS  Google Scholar 

  9. Davis GM, Cooper DM, Mitchell I (1993) The measurement of thoracoabdominal asynchrony in infants with severe laryngotracheobronchitis. Chest 103:1842–1848

    Article  PubMed  CAS  Google Scholar 

  10. Corkey CWB, Barker GA, Edmonds JF, Mok PM, Newth CJL (1981) Radiographic tracheal diameter measurements in acute infectious croup: an objective scoring system. Crit Care Med 9:587–590

    Article  PubMed  CAS  Google Scholar 

  11. Newth CJL, Lipton MJ, Gould RG, Stretton M (1990) Varying tracheal cross-sectional area during respiration in infants and children with suspected upper airway obstruction by computed cinetomography scanning. Pediatr Pulmonol 9:224–232

    Article  PubMed  CAS  Google Scholar 

  12. Lenny W, Milner AD (1978) Treatment of acute viral croup. Arch Dis Child 53:704–706

    Article  Google Scholar 

  13. Fanconi S, Burger R, Maurer H, Uehlinger J, Ghelfi D, Mühlemann C (1990) Transcutaneous carbon dioxide pressure for monitoring patients with severe croup. J Pediatr 117:710–705

    Google Scholar 

  14. Westley CR, Cotton EK, Brooks JG (1978) Nebulized racemic epinephrine by IPPB for the treatment of croup: a double-blind study. Am J Dis Child 132:484–487

    PubMed  CAS  Google Scholar 

  15. Newton-John H (1977) Pulmonary oedema in upper airway obstruction. Lancet 2(8036):510

    Article  PubMed  CAS  Google Scholar 

  16. Luke MJ, Mehrizi A, Folger GM Jr, Rowe RD (1966) Chronic nasopharyngeal obstruction as a cause of cardiomegaly, cor pulmonale, and pulmonary edema. Pediatrics 37:762–768

    PubMed  CAS  Google Scholar 

  17. Klein M (1986) Croup, epiglottitis and the febrile dysphagia syndrome. S Afr J Cont Med Educ 4:45–51

    Google Scholar 

  18. Asher MI, Coates AL, Collinge JM, Milic-Emili J (1982) Measurement of pleural pressure in neonates. J Appl Physiol 52:491–494

    PubMed  CAS  Google Scholar 

  19. Le Souef PN, Lopes JM, England SS, Bryan MH, Bryan AC (1983) Influence of chest wall distortion on esophageal pressure. J Appl Physiol 55:353–358

    Google Scholar 

  20. Downs JA, Stocks J (1995) Effect of neck rotation on the timing and pattern of infant tidal breathing. Pediatr Pulmonol 20:380–386

    Article  PubMed  CAS  Google Scholar 

  21. Mead J, Whittenberger JL (1953) Physical properties of human lungs measured during spontaneous respiration. J Appl Physiol 5:779–796

    Google Scholar 

  22. Otis AB (1954) The work of breathing. Physiol Rev 34:449–458

    PubMed  CAS  Google Scholar 

  23. Dodd DS, Kelly S, Collett PW, Engel LA (1988) Pressure-time product, work rate, and endurance during resistive breathing in humans. J Appl Physiol 64:1397–1404

    PubMed  CAS  Google Scholar 

  24. Klein M, Reynolds LG (1986) Relief of sleep-related oropharyngeal airway obstruction by continuous insufflation of the pharynx. Lancet i:935–939

    Article  Google Scholar 

  25. Milner AD, Saunders RA, Hopkin IE (1978) Relationship of intra-oesophageal pressure to mouth pressure during the measurement of thoracic gas volume in the newborn. Biol Neonate 33:314–319

    Article  PubMed  CAS  Google Scholar 

  26. Beardsmore CS, Godfrey S, Shani N, Maayan C, Bar-Yishay E (1986) Airway resistance measurements throughout the respiratory cycle in infants. Respiration 49:81–93

    PubMed  CAS  Google Scholar 

  27. Dawson SV, Elliott EA (1977) Wave-speed limitation on expiratory flow – a unifying concept. J Appl Physiol 43:498–515

    PubMed  CAS  Google Scholar 

  28. Shapiro AH (1977) Steady flow in collapsible tubes. J Biomech Eng 99:126–147

    Google Scholar 

  29. Elad D, Kamm RD, Shapiro AH (1988) Mathematical simulation of forced expiration. J Appl Physiol 65:14–25

    PubMed  CAS  Google Scholar 

  30. Wittenborg MH, Gyepes MT, Crocker D (1967) Tracheal dynamics in infants with respiratory distress, stridor and collapsing trachea. Radiology 88:653–662

    PubMed  CAS  Google Scholar 

  31. Harrison VC, de Heese H, Klein M (1968) The significance of grunting in hyaline membrane disease. Pediatrics 41:549–559

    PubMed  CAS  Google Scholar 

  32. Cutrera R, Filtchev SI, Merolla R, Willim G, Haluszka J, Ronchetti R (1991) Analysis of expiratory pattern for monitoring bronchial obstruction in school-age children. Pediatr Pulmonol 10:6–10

    Article  PubMed  CAS  Google Scholar 

  33. Mikkilineni S, England S (1994) On tidal expiratory flow measurements in infants. Pediatr Pulmonol 18:71–72

    Article  PubMed  CAS  Google Scholar 

  34. Vermaak JC, Bunn AE, de Kock MA (1979) A new lung function index. The area under the maximum expiratory flow-volume curve. Respiration 37:61–65

    Article  PubMed  CAS  Google Scholar 

  35. Steele DW, Santucci KA, Wright RO, Natarajan R, McQuillen KK, Jay GD (1998) Pulsus paradoxus. An objective measure of severity in croup. Am J Respir Crit Care Med 157:331–334

    PubMed  CAS  Google Scholar 

  36. Stokes GM, Milner AD, Groggins RC (1981) Work of breathing, intra-thoracic pressure and clinical findings in a group of babies with bronchiolitis. Acta Paediatr Scand 70:689–694

    Article  PubMed  CAS  Google Scholar 

  37. Krieger I, Whittenn CF (1964) Work of respiration in bronchiolitis. Am J Dis Child 107:386–392

    PubMed  CAS  Google Scholar 

  38. McGregor M, Becklake MR (1961) The relationship of oxygen cost of breathing to respiratory mechanical work and respiratory force. J Clin Invest 40:971–980

    PubMed  CAS  Google Scholar 

  39. Rochester DF, Bettini G (1976) Diaphragmatic blood flow and energy expenditure in the dog. J Clin Invest 57:661–672

    Article  PubMed  CAS  Google Scholar 

  40. Robertson CH, Foster GH, Johnson RL (1977) The relationship of respiratory failure to the oxygen consumption of, lactate production by, and distribution of blood flow among respiratory muscles during increasing inspiratory resistance. J Clin Invest 59:31–42

    PubMed  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Division of Paediatric Critical Care and Children’s Heart Disease, School of Child and Adolescent Health, University of Cape Town, Cape Town, South Africa

    Andrew C. Argent

  2. Red Cross War Memorial Children’s Hospital, Cape Town, South Africa

    Andrew C. Argent & Max Klein

  3. Division of Critical Care Medicine, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA

    Christopher J. L. Newth

  4. Paediatric Pulmonology Services, School of Child and Adolescent Health, University of Cape Town, Cape Town, South Africa

    Max Klein

Authors
  1. Andrew C. Argent
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Christopher J. L. Newth
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Max Klein
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Andrew C. Argent.

Additional information

Declaration: The authors are neither supported by, nor maintain any financial interest in, any commercial activity associated with the topic of this article.

Electronic supplementary material

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Argent, A.C., Newth, C.J.L. & Klein, M. The mechanics of breathing in children with acute severe croup. Intensive Care Med 34, 324–332 (2008). https://doi.org/10.1007/s00134-007-0910-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00134-007-0910-x

Keywords

search

Navigation