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Real‐time ventilation and perfusion distributions by electrical impedance tomography during one‐lung ventilation with capnothorax
Author(s) -
REINIUS H.,
BORGES J. B.,
FREDÉN F.,
JIDEUS L.,
CAMARGO E. D. L. B.,
AMATO M. B. P.,
HEDENSTIERNA G.,
LARSSON A.,
LENNMYR F.
Publication year - 2015
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/aas.12455
Subject(s) - medicine , ventilation (architecture) , anesthesia , oxygenation , perfusion , hemodynamics , electrical impedance tomography , lung , peak inspiratory pressure , insufflation , cardiology , respiratory system , tomography , radiology , tidal volume , mechanical engineering , engineering
Background Carbon dioxide insufflation into the pleural cavity, capnothorax , with one‐lung ventilation ( OLV ) may entail respiratory and hemodynamic impairments. We investigated the online physiological effects of OLV /capnothorax by electrical impedance tomography ( EIT ) in a porcine model mimicking the clinical setting. Methods Five anesthetized, muscle‐relaxed piglets were subjected to first right and then left capnothorax with an intra‐pleural pressure of 19 cm H 2 O . The contra‐lateral lung was mechanically ventilated with a double‐lumen tube at positive end‐expiratory pressure 5 and subsequently 10 cm H 2 O . Regional lung perfusion and ventilation were assessed by EIT . Hemodynamics, cerebral tissue oxygenation and lung gas exchange were also measured. Results During right‐sided capnothorax, mixed venous oxygen saturation ( P = 0.018), as well as a tissue oxygenation index ( P = 0.038) decreased. There was also an increase in central venous pressure ( P = 0.006), and a decrease in mean arterial pressure ( P = 0.045) and cardiac output ( P = 0.017). During the left‐sided capnothorax, the hemodynamic impairment was less than during the right side. EIT revealed that during the first period of OLV /capnothorax, no or very minor ventilation on the right side could be seen (3 ± 3% vs. 97 ± 3%, right vs. left, P = 0.007), perfusion decreased in the non‐ventilated and increased in the ventilated lung (18 ± 2% vs. 82 ± 2%, right vs. left, P = 0.03). During the second OLV /capnothorax period, a similar distribution of perfusion was seen in the animals with successful separation (84 ± 4% vs. 16 ± 4%, right vs. left). Conclusion EIT detected in real‐time dynamic changes in pulmonary ventilation and perfusion distributions. OLV to the left lung with right‐sided capnothorax caused a decrease in cardiac output, arterial oxygenation and mixed venous saturation.