Skip to main content
PMC home page
Thorax logoLink to Thorax
. 2003 Jan;58(1):58–62. doi: 10.1136/thorax.58.1.58

Can diaphragmatic contractility be assessed by airway twitch pressure in mechanically ventilated patients?

S Cattapan 1, F Laghi 1, M Tobin 1
PMCID: PMC1746444  PMID: 12511723

Abstract

Background: In critically ill patients inspiratory muscle function may be assessed by measurements of maximal inspiratory airway pressure and the response of twitch transdiaphragmatic pressure (Pdi tw) to bilateral phrenic nerve stimulation. The first is limited by its total dependence on patient cooperation. Although the second approach is independent of patient volition, it is impractical because it requires oesophageal and gastric balloons. Because airway pressure is easily and non-invasively recorded in patients with artificial airways, we hypothesised that twitch airway pressure (Paw tw) reliably predicts Pdi tw and twitch oesophageal pressure (Poes tw) in mechanically ventilated patients.

Methods: Thirteen mechanically ventilated patients recovering from an episode of acute respiratory failure received phrenic nerve stimulation at end exhalation. The rapid occlusion technique was used to record respiratory system mechanics.

Results: Stimulations were well tolerated. Mean (SE) Paw tw at end exhalation was –8.2 (1.2) cm H2O and Poes tw and Pdi tw were –7.3 (1.1) and 10.4 (1.8) cm H2O, respectively. Stimulations produced a good correlation between Paw tw and Pdi tw (p<0.001), although the limits of agreement were wide. The results were similar for Poes tw. No relationship was found between the Paw tw/Poes tw ratio and respiratory system compliance or airway resistance. Paw tw reproducibility was excellent (mean coefficient of variation 6%, range 3–9%).

Conclusions: Despite a good correlation between Paw tw and Poes tw, Paw tw did not reliably predict Poes tw or Pdi tw in mechanically ventilated patients. Nevertheless, the excellent reproducibility of Paw tw suggests that it may be a useful means of monitoring inspiratory muscle contractility in the routine care of mechanically ventilated patients.

Full Text

The Full Text of this article is available as a PDF (152.3 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Attali V., Mehiri S., Straus C., Salachas F., Arnulf I., Meininger V., Derenne J. P., Similowski T. Influence of neck muscles on mouth pressure response to cervical magnetic stimulation. Am J Respir Crit Care Med. 1997 Aug;156(2 Pt 1):509–514. doi: 10.1164/ajrccm.156.2.9612053. [DOI] [PubMed] [Google Scholar]
  2. Baydur A., Behrakis P. K., Zin W. A., Jaeger M., Milic-Emili J. A simple method for assessing the validity of the esophageal balloon technique. Am Rev Respir Dis. 1982 Nov;126(5):788–791. doi: 10.1164/arrd.1982.126.5.788. [DOI] [PubMed] [Google Scholar]
  3. Bland J. M., Altman D. G. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet. 1986 Feb 8;1(8476):307–310. [PubMed] [Google Scholar]
  4. Hamnegåard C. H., Wragg S., Kyroussis D., Mills G., Bake B., Green M., Moxham J. Mouth pressure in response to magnetic stimulation of the phrenic nerves. Thorax. 1995 Jun;50(6):620–624. doi: 10.1136/thx.50.6.620. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Hatipoğlu U., Laghi F., Tobin M. J. Does inhaled albuterol improve diaphragmatic contractility in patients with chronic obstructive pulmonary disease? Am J Respir Crit Care Med. 1999 Dec;160(6):1916–1921. doi: 10.1164/ajrccm.160.6.9903122. [DOI] [PubMed] [Google Scholar]
  6. Jubran A., Tobin M. J. Passive mechanics of lung and chest wall in patients who failed or succeeded in trials of weaning. Am J Respir Crit Care Med. 1997 Mar;155(3):916–921. doi: 10.1164/ajrccm.155.3.9117026. [DOI] [PubMed] [Google Scholar]
  7. Jubran A., Van de Graaff W. B., Tobin M. J. Variability of patient-ventilator interaction with pressure support ventilation in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 1995 Jul;152(1):129–136. doi: 10.1164/ajrccm.152.1.7599811. [DOI] [PubMed] [Google Scholar]
  8. Laghi F., Harrison M. J., Tobin M. J. Comparison of magnetic and electrical phrenic nerve stimulation in assessment of diaphragmatic contractility. J Appl Physiol (1985) 1996 May;80(5):1731–1742. doi: 10.1152/jappl.1996.80.5.1731. [DOI] [PubMed] [Google Scholar]
  9. Laghi F., Jubran A., Topeli A., Fahey P. J., Garrity E. R., Jr, Arcidi J. M., de Pinto D. J., Edwards L. C., Tobin M. J. Effect of lung volume reduction surgery on neuromechanical coupling of the diaphragm. Am J Respir Crit Care Med. 1998 Feb;157(2):475–483. doi: 10.1164/ajrccm.157.2.9705082. [DOI] [PubMed] [Google Scholar]
  10. Laghi F., Tobin M. J. Relationship between transdiaphragmatic and mouth twitch pressures at functional residual capacity. Eur Respir J. 1997 Mar;10(3):530–536. [PubMed] [Google Scholar]
  11. Similowski T., Gauthier A. P., Yan S., Macklem P. T., Bellemare F. Assessment of diaphragm function using mouth pressure twitches in chronic obstructive pulmonary disease patients. Am Rev Respir Dis. 1993 Apr;147(4):850–856. doi: 10.1164/ajrccm/147.4.850. [DOI] [PubMed] [Google Scholar]
  12. Similowski T., Straus C., Attali V., Duguet A., Derenne J. P. Cervical magnetic stimulation as a method to discriminate between diaphragm and rib cage muscle fatigue. J Appl Physiol (1985) 1998 May;84(5):1692–1700. doi: 10.1152/jappl.1998.84.5.1692. [DOI] [PubMed] [Google Scholar]
  13. Topeli A., Laghi F., Tobin M. J. Can diaphragmatic contractility be assessed by twitch airway pressures in patients with chronic obstructive pulmonary disease? Am J Respir Crit Care Med. 1999 Oct;160(4):1369–1374. doi: 10.1164/ajrccm.160.4.9806041. [DOI] [PubMed] [Google Scholar]
  14. Watson A. C., Hughes P. D., Louise Harris M., Hart N., Ware R. J., Wendon J., Green M., Moxham J. Measurement of twitch transdiaphragmatic, esophageal, and endotracheal tube pressure with bilateral anterolateral magnetic phrenic nerve stimulation in patients in the intensive care unit. Crit Care Med. 2001 Jul;29(7):1325–1331. doi: 10.1097/00003246-200107000-00005. [DOI] [PubMed] [Google Scholar]
  15. Yan S., Gauthier A. P., Similowski T., Macklem P. T., Bellemare F. Evaluation of human diaphragm contractility using mouth pressure twitches. Am Rev Respir Dis. 1992 May;145(5):1064–1069. doi: 10.1164/ajrccm/145.5.1064. [DOI] [PubMed] [Google Scholar]
  16. Yang K. L., Tobin M. J. A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation. N Engl J Med. 1991 May 23;324(21):1445–1450. doi: 10.1056/NEJM199105233242101. [DOI] [PubMed] [Google Scholar]

Articles from Thorax are provided here courtesy of BMJ Publishing Group

RESOURCES