Log in | Register

A method for monitoring and improving patient: ventilator interaction

Magdy Younes| Laurent Brochard| Salvatore Grasso| John Kun| Jordi Mancebo| Marco Ranieri| Jean-Christophe Richard| Henry Younes
Original
Volume 33, Issue 8 / August , 2007

Pages 1337 - 1346

Abstract

Objective

To evaluate a new approach for monitoring and improving patient-ventilator interaction that utilizes a signal generated by the equation of motion, using improvised values for resistance and elastance obtained noninvasively.

Design and setting

Observational study in intensive care units in five European centers.

Patients

We studied 21 stable patients instrumented with esophageal/gastric catheters for a previous study and ventilated alternately with pressure support (PSV) and proportional assist (PAV) ventilation with a Tyco 840 ventilator.

Measurements and results

Previously recorded digital files were analyzed in real-time by a prototype incorporating the new technology (PVI monitor, YRT, Winnipeg, Canada). Actual onsets (PDI-TONSET) and ends (PDI-TEND) of inspiratory efforts, ineffective efforts, and patient respiratory rate were identified visually from transdiaphragmatic or calculated respiratory muscle pressure. Monitor-identified TONSET occurred 0.107 ± 0.074 s after PDI-TONSET, substantially less than trigger delay observed with conventional triggering (0.326 ± 0.086 s). End of effort was identified 0.097 ± 0.096 s after PDI-TEND, significantly less than actual cycling-off delay during PSV (0.486 ± 0.307 s) or PAV (0.277 ± 0.084 s). The monitor detected 80% of ineffective efforts. There was excellent agreement between monitor-estimated respiratory rate and actual patient rate over a wide range (17–59/min) of patient rates (mean ( ± SD) of difference −0.2 ± 1.9/min for pressure support and 0.2 ± 0.9/min for proportional assist) even when large discrepancies existed (> 35/min) between patient and ventilator rates.

Conclusions

The proposed approach should make it possible to improve patient-ventilator interaction and to obtain accurate estimates of true patient respiratory rate when there is nonsynchrony.

Keywords

References

  1. Leung P, Jubran A, Tobin MJ (1997) Comparison of assisted ventilator modes on triggering, patient effort, and dyspnea. Am J Respir Crit Care Med 155:1940–1948
    • View reference on PubMed
  2. Tobin MJ, Jubran A, Laghi F (2001) Patient-ventilator interaction. Am J Respir Crit Care Med 163:1059–1063
    • View reference on PubMed
  3. Kondili E, Prinianakis G, Georgopoulos D (2003) Patient-ventilator interaction. Br J Anaesthesia 91:106–119
    • View reference on publisher's website
  4. Prinianakis G, Kondili E, Georgopoulos D (2003) Effects of the flow waveform method of triggering and cycling on patient-ventilator interaction during pressure support. Intensive Care Med 29:1950–1959
  5. Giannouli E, Webster K, Roberts D, Younes M (1999) Response of ventilator-dependent patients to different levels of pressure support and proportional assist. Am J Respir Crit Care Med 159:1716–1725
    • View reference on PubMed
  6. Thille AW, Rodriguez P, Cabello B, Lellouche F, Brochard L (2006) Patient-ventilator asynchrony during assisted mechanical ventilation. Intensive Care Med 32:1515–1522
  7. Younes M (2006) Proportional assist ventilation. In: Tobin MJ (ed) Principles and practice of mechanical ventilation, 2nd edn. McGraw-Hill, New York, pp 335–364
  8. Younes M (2003) Method and device for monitoring and improving patient-ventilator interaction. PCT application #PCT/CA 2003/000976
  9. Mead J, Agostoni E (1964) Dynamics of breathing. In: Fenn WO, Rahn H (eds) Handbook of physiology: respiration. American Physiological Society. Washington, pp 411–427
  10. Younes M (1992) Proportional assist ventilation, a new approach to ventilatory support. Theory. Am Rev Respir Dis 145:114–120
    • View reference on PubMed
  11. Grasso S, Ranieri VM, Brochard L, Richard GC, Mancebo J, Slutsky AS, Younes M (2001) Closed loop proportional assist ventilation (PAV): results of a phase II multicenter trial. Am J Respir Crit Care Med 163:303A
  12. Campbell EJM (1958) The respiratory muscles and mechanics of breathing. Loyd-Luke, London
  13. Appendini L, Patessio A, Zanaboni S, Carone M, Gukov B, Donner CF, Rossi A (1994) Physiologic effects of positive end-expiratory pressure and mask pressure support during exacerbations of chronic obstructive pulmonary disease. Am J Respir Crit Care Med 149:1069–1076
    • View reference on PubMed
  14. Younes M (1993) Patient-ventilator interaction with pressure-assisted modalities of ventilatory support. Semin Respir Med 14:299–322
  15. Mancebo J (2003) Triggering and cycling off during pressure support ventilation: simplicity or sophistication? Intensive Care Med 29:1871–1872
  16. Imanaka H, Nishimura M, Takeuchi M, Kimball WR, Yahagi N, Kumon K (2000) Autotriggering caused by cardiogenic oscillation during flow-triggered mechanical ventilation. Crit Care Med 28:402–407
    • View reference on PubMed
    • View reference on publisher's website
  17. Younes M, Remmers JE (1981) Control of tidal volume and respiratory frequency. In: Hornbein T (ed) Control of breathing. Lung biology in health and disease, vol. 17 Dekker, New York. pp 617–667
  18. Agostoni E, Citterio G, D'Angelo E (1979) Decay rate of inspiratory muscle pressure during expiration in man. Respir Physiol 36:269–285
    • View reference on PubMed
    • View reference on publisher's website
  19. Younes M. Kun J, Masiowski B, Webster K, Roberts D (2001) A method for noninvasive determination of inspiratory resistance during proportional assist ventilation. Am J Respir Crit Care Med 163:829–839
  20. Younes M, Webster K, Kun J, Roberts D, Masiowski B (2001) A method for measuring passive elastance during proportional assist ventilation. Am J Respir Crit Care Med 164:50–60
    • View reference on PubMed
  21. Fernandez F, Mendez M, Younes M (1999) Effect of ventilator flow-rate on respiratory timing in normal subjects. Am J Respir Crit Care Med 159:710–719
    • View reference on PubMed
  22. Nava S, Bruschi C, Rubini F, Palo A, Iotti G, Braschi A (1995) Respiratory response to inspiratory effort during pressure support ventilation in COPD patients. Intensive Care Med 21:871–879
  23. Yamada Y, Shigeta M, Suwa K, Hanaoka K (1994) Respiratory muscle pressure analysis in pressure-support ventilation. J Appl Physiol 77:2237–2243
    • View reference on PubMed
  24. Younes M, Kun J, Webster K, Roberts D (2002) Response of ventilator dependent patients to delayed opening of exhalation valve. Am J Respir Crit Care Med 166:21–30
    • View reference on PubMed
    • View reference on publisher's website

Sign In

Connect with ICM

Top 5 Articles Editors Picks Supplement