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Incidence of venous and paradoxical air embolism in neurosurgical patients in the sitting position: Detection by transesophageal echocardiography
Author(s) -
Mammoto T.,
Hayashi Y.,
Ohnishi Y.,
Kuro M.
Publication year - 1998
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/j.1399-6576.1998.tb05295.x
Subject(s) - medicine , sitting , cardiology , incidence (geometry) , microbubbles , air embolism , anesthesia , embolism , neurosurgery , pulmonary artery , hemodynamics , surgery , radiology , ultrasound , complication , pathology , physics , optics
Background: Venous air embolism (VAE) and paradoxical air embolism (PAE) are serious complications associated with the sitting position for neurosurgery. Although PAE is the result of VAE, the incidence of PAE according to the severity of VAE has not been investigated systematically in humans. Methods: Twenty‐one patients scheduled for neurosurgery in the sitting position were investigated prospectively. VAE and PAE were continuously monitored by cardiac two‐dimensional 4‐chamber view using transesophageal echocardiography (TEE) and the severity of VAE and PAE was quantitatively graded from 0 to 3 by the microbubbles score. Haemodynamic parameters and end‐tidal CO 2 concentration (P ET CO 2 ) during VAE and PAE were also recorded. Results: Microbubbles in the right atrium appeared in all patients and the number of patients involved in grades 0, 1, 2 and 3 of VAE was 0, 10, 3 and 8, respectively. PAE occurred in 3 patients and only followed grade 3 of VAE. PAE always appeared from 20 to 30 s after the most severe VAE. A reduction of P ET CO 2 and an increase of pulmonary artery pressure were noted during all episodes of grades 2 and 3 VAE. In contrast, a significant reduction of systemic blood pressure occurred in 1 case of grade 2 and 3 cases of grade 3. Conclusions: VAE detected by TEE appeared in all patients undergoing neurosurgery in the sitting position and PAE only occurred following the most severe grade of VAE. To prevent growth of VAE is an important prophylactic for PAE.