This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Babik, B. Articles by Hantos, Z. Search for Related Content PubMed PubMed Citation Articles by Babik, B. Articles by Hantos, Z. Related Collections Cardiovascular Monitoring (Cardiac) Monitoring (Non-cardiac)

---

CARDIOVASCULAR ANESTHESIA

Changes in Respiratory Mechanics During Cardiac Surgery

Barna Babik, MD^*,, Tibor Asztalos, PhD, Ferenc Peták, PhD, Zoltán I. Deák, MD^*,, and Zoltán Hantos, PhD

*Institute of Anesthesiology and Intensive Therapy, Division of Cardiac Surgery, and Department of Medical Informatics and Engineering, University of Szeged, Szeged, Hungary

Address correspondence and reprint requests to Zoltán Hantos, PhD, Department of Medical Informatics and Engineering, University of Szeged, PO Box 427, H-6701 Szeged, Hungary. Address e-mail to hantos{at}dmi.u-szeged.hu

We investigated the role of cardiopulmonary bypass (CPB) in compromised lung function associated with cardiac surgery. Low-frequency respiratory impedance (Zrs) was measured in patients undergoing cardiac surgery with (n = 30; CPB group) or without (n = 29; off-pump coronary artery bypass [OPCAB] group) CPB. Another group of CPB patients received dopamine (DA) (n = 12; CPB-DA group). Extravascular lung water was determined in five CPB subjects. Zrs was measured before skin incision and after chest closure. Airway resistance and inertance and tissue damping and elastance were determined from Zrs data. Airway resistance increased in the CPB group (74.9% ± 20.8%; P < 0.05), whereas it did not change in the OPCAB group (11.8% ± 7.9%; not significant) and even decreased in the CPB-DA patients (-40.6% ± 9.2%; P < 0.05). Tissue damping increased in the CPB and OPCAB groups, whereas it remained constant in the CPB-DA patients. Significant increases in elastance were observed in all groups. There was no difference in extravascular lung water before and after CPB, suggesting that edema did not develop. These results indicate a significant and heterogeneous airway narrowing during CPB, which was counteracted by the administration of DA. The mild deterioration in tissue mechanics, reflecting partial closure of the airways, may be a consequence of the anesthesia itself.

IMPLICATIONS: We observed that cardiopulmonary bypass deteriorates lung function by inducing a heterogeneous airway constriction, whereas no such effects were observed in patients undergoing cardiac surgery without bypass. The impairment in parenchymal mechanics, which was obtained in both groups, may result from peripheral airway closure and/or be a consequence of mediator release.

This article has been cited by other articles:

				J. M. Schultz, T. Karamlou, J. Swanson, I. Shen, and R. M. Ungerleider Hypothermic Low-Flow Cardiopulmonary Bypass Impairs Pulmonary and Right Ventricular Function More Than Circulatory Arrest Ann. Thorac. Surg., February 1, 2006; 81(2): 474 - 480. [Abstract] [Full Text] [PDF]

				G. W. Staton, W. H. Williams, E. M. Mahoney, J. Hu, H. Chu, P. G. Duke, and J. D. Puskas Pulmonary Outcomes of Off-Pump vs On-Pump Coronary Artery Bypass Surgery in a Randomized Trial Chest, March 1, 2005; 127(3): 892 - 901. [Abstract] [Full Text] [PDF]

				C. Weissman Pulmonary Complications After Cardiac Surgery Seminars in Cardiothoracic and Vascular Anesthesia, September 1, 2004; 8(3): 185 - 211. [Abstract] [PDF]