Electrical impedance tomography to confirm correct placement of double-lumen tube: a feasibility study.
BACKGROUND
Double-lumen tubes (DLTs) are frequently used to establish one-lung ventilation (OLV). Their correct placement is crucial. We hypothesized that electrical impedance tomography (EIT) reliably displays distribution of ventilation between left and right lung and may thus be used to verify correct DLT placement online.


METHODS
Regional ventilation was studied by EIT in 40 patients requiring insertion of left-sided DLTs for OLV during thoracic surgery. EIT was recorded during two-lung ventilation before induction of anaesthesia and after DLT placement, and during OLV in the supine and subsequently in the lateral position. EIT measurements were made before and after verification of correct DLT placement by fibreoptic bronchoscopy (FOB).


RESULTS
EIT accurately displayed distribution of ventilation between left and right lung online. All cases (n=5) of initially misplaced DLTs in the contralateral right main bronchus were detected by EIT. However, EIT did not allow prediction of FOB-detected endobronchial cuff misplacement requiring DLT repositioning. Furthermore, after DLT repositioning, distribution of ventilation, as assessed by EIT, did not change significantly (all P>0.5).


CONCLUSIONS
This study demonstrates that EIT enables accurate display of left and right lung ventilation and, thus, non-invasive online recognition of misplacement of left-sided DLTs in the contralateral main bronchus. However, as distribution of ventilation did not correlate with endobronchial cuff placement, EIT cannot replace FOB in the routine control of DLT position.
Department of Anaesthesia and Critical Care Medicine, University Medical Center Freiburg, Hugstetter Strasse 55, D-79106 Freiburg, Germany. daniel.steinmann@uniklinik-freiburg.de
D
D
Steinmann
C A
CA
Stahl
J
J
Minner
S
S
Schumann
T
T
Loop
A
A
Kirschbaum
H J
HJ
Priebe
J
J
Guttmann
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001980:Bronchi; D001999:Bronchoscopy; D017097:Electric Impedance; D005240:Feasibility Studies; D005260:Female; D005336:Fiber Optic Technology; D005547:Foreign Bodies / Q000175:diagnosis; D006801:Humans; D007442:Intubation, Intratracheal / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial / Q000379:methods*; D019616:Thoracic Surgical Procedures; D014054:Tomography / Q000379:methods