Intensive Care Medicine

, Volume 30, Issue 1, pp 82–87 | Cite as

A comparative evaluation of thermodilution and partial CO2 rebreathing techniques for cardiac output assessment in critically ill patients during assisted ventilation

  • Monica Rocco
  • Gustavo Spadetta
  • Andrea Morelli
  • Donatella Dell’Utri
  • Patrizia Porzi
  • Giorgio Conti
  • Paolo Pietropaoli
Original

Abstract

Objective

To evaluate the reliability and clinical value of partial noninvasive CO2 (NICO2) rebreathing technique for measuring cardiac output compared with standard thermodilution in a group of intensive care nonpostoperative patients.

Design and setting

Clinical investigation in a university hospital ICU.

Patients

Twelve mechanically ventilated patients with high ( n =6) and low ( n =6) pulmonary shunt fractions.

Measurements and results

Thirty-six paired measurements of cardiac output were carried out with NICO2 and thermodilution in patients ventilated in pressure-support mode and sedated with a sufentanil continuous infusion to obtain a Ramsay score value of 2. The mean cardiac output was: thermodilution 7.27±2.42 l/min; NICO2 6.10±1.66 l/min; r 2 was 0.62 and bias −1.2 l/min±1.5. Mean values of cardiac output were similar in the low shunt group (\( {\dot{\text {Q}}} {\text {s}} /\ {\dot{\text {Q}}} {\text {t}} < 20 \)), with r2=0.90 and a bias of 0.01 l/min±0.4; conversely, in the high pulmonary shunt group (\( {\dot{\text {Q}}} {\text {s}} /\ {\dot{\text {Q}}} > 35\% \)) the mean was 9.32±1.23 l/min with thermodilution and a mean NICO2CO value was 6.97±1.53 l/min, with r2 of 0.38 and a bias of −2.3 l±1.2 min.

Conclusions

The partial CO2 rebreathing technique is reliable in measuring cardiac output in nonpostoperative critically ill patients affected by diseases causing low levels of pulmonary shunt, but underestimates it in patients with shunt higher than 35%.

Keywords

Noninvasive CO2 rebreathing technique Thermodilution Cardiac output Hemodynamic evaluation Pulmonary shunt 

References

  1. 1.
    Dalen JE, Bone RC (1996) Is it time to pull the pulmonary artery catheter? JAMA 276:916–918PubMedGoogle Scholar
  2. 2.
    Mimioz O, Rauss A, Rekik N (1994) Pulmonary artery catheterisation in critically ill patients: a prospective analysis of outcome changes associated with catheter-prompted changes in therapy. Crit Care Med 22:573–579PubMedGoogle Scholar
  3. 3.
    Rivers E, Nguyen B, Havstad S (2001) Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med 345:1368–1377PubMedGoogle Scholar
  4. 4.
    Swan HJC, Ganz W, Forester J (1970) Catheterization of the heart in man with use of a flow directed balloon-tipped catheter. N Engl J Med 283:447–451PubMedGoogle Scholar
  5. 5.
    Polderman KH, Girbes ARJ (2002) Central venous catheter use. I. Mechanical complications. Intensive Care Med 28:1–17PubMedGoogle Scholar
  6. 6.
    Poldermann KH, Girbes ARJ (2002) Central venous catheter use. II. Infectious complications. Intensive Care Med 28:18–28PubMedGoogle Scholar
  7. 7.
    Ramsay MAE, Savage TM, Simpson BRJ (1974) Controlled sedation with alphaxalone-alphadolone. BMJ 2:656–659PubMedGoogle Scholar
  8. 8.
    Jaffe MB (1999) Partial CO2 rebreathing cardiac output operating principle of the NICO system. J Clin Monit Comput 15:387–401CrossRefPubMedGoogle Scholar
  9. 9.
    Nunn JF (1993) Nunn’s applied respiratory physiology, 4th edn. Butterworth, OxfordGoogle Scholar
  10. 10.
    Bland MJ, Altman DG (1986) Statistical methods for assessing agreement between two methods of clinical measurement. Lancet I:307–310Google Scholar
  11. 11.
    Gedeon A, Forstund L, Hedenstierna G, Romano E (1980) A new method for non invasive bedside determination of pulmonary blood flow. Med Biol Eng Comput 18:411–418PubMedGoogle Scholar
  12. 12.
    Capek JM, Roy RJ (1988) Non invasive measurement of cardiac output using partial CO2 rebreathing. IEEE Trans Biomed Eng 35:653–661CrossRefPubMedGoogle Scholar
  13. 13.
    Osterlund B, Gedeon A, Krill P, Johansson G (1995) A new method of using gas exchange measurements for the non-invasive determination of cardiac output: clinical experience in adults following cardiac surgery. Acta Anaesthesiol Scand 39:727–732PubMedGoogle Scholar
  14. 14.
    Van Heerden PV, Baker S, Lim SI, Weidman C, Bulsara M (2000) Clinical evaluation of the non-invasive cardiac output (NICO) monitor in the intensive care unit. Anaesth Intensive Care 28:427–430PubMedGoogle Scholar
  15. 15.
    Odenstedt H, Stenquist O, Lundin S (2002) Clinical evaluation of partial CO2 rebreathing technique for cardiac output monitoring in critically ill patients. Acta Anaesthesiol Scand 46:152–159CrossRefPubMedGoogle Scholar
  16. 16.
    Tachibana K, Imanaka H, Miyano H, Takeuchi M, Kumon K, Nishimura M (2002) Effect of ventilatory settings on accuracy of cardiac output measurement using partial CO2 rebreathing Anesthesiology 96:96–102Google Scholar
  17. 17.
    Binder JC, Parkin WG (2001) Non-invasive cardiac output determination: comparison of a new partial-rebreathing technique with thermodilution. Anaesth Intensive Care 29:19–23PubMedGoogle Scholar
  18. 18.
    Nilsson LB, Eldrup N, Berthelsen PG (2001) Lack of agreement between thermodilution and carbon dioxide rebreathing cardiac output. Acta Anaesthesiol Scand 45:680–685PubMedGoogle Scholar
  19. 19.
    Gama de Abreu M, Quintel M, Ragaller M, Albrecht DM (1997) Partial carbon dioxide rebreathing: a reliable technique for non-invasive measurement of non-shunted pulmonary capillary blood flow. Crit Care Med 25:675–683PubMedGoogle Scholar
  20. 20.
    Gama de Abreu M, Geiger S, Winkler T, Ragaller M, Pfeiffer T, Leutheuser D, Albrecht DM (2002) Evaluation of a new device for non invasive measurement of non shunted pulmonary capillary blood flow in patients with acute lung injury. Intensive Care Med 28:318–323CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Monica Rocco
    • 1
  • Gustavo Spadetta
    • 1
  • Andrea Morelli
    • 1
  • Donatella Dell’Utri
    • 1
  • Patrizia Porzi
    • 1
  • Giorgio Conti
    • 2
  • Paolo Pietropaoli
    • 1
  1. 1.Department of Anesthesiology and Intensive CareUniversity of Rome La SapienzaRomeItaly
  2. 2.Department of Anesthesiology and Intensive CareCatholic University of RomeRomeItaly

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