External defibrillation in the left lateral position--a comparison of manual paddles with self-adhesive pads.
BACKGROUND
Firm paddle force during defibrillation lowers transthoracic impedance (TTI) and increases transmyocardial current, increasing the chances of successful cardioversion. Current protocols recommend that if defibrillation using the anterior-apical (AA) paddle position fails, the anterior-posterior (AP) position should be used. This generally requires the patient to be placed in the left lateral position with the operator leaning over the patient. Avoiding physical contact with the patient during defibrillation subjectively makes application of firm paddle force difficult in the AP position. We compared TTI between the AA and AP positions and between manual paddles and self-adhesive pads to establish if the AP position precludes firm paddle force and to compare TTI between paddles and self-adhesive pads.


METHODS
Twenty-one consecutive patients undergoing elective cardioversion (age 39-82) were studied. TTI was measured between pairs of manually held paddles and self-adhesive pads using AA placement with the patient supine, and AP placement with the patient left lateral position.


RESULTS
Mean TTI using the AP electrode position was lower using manual paddles (66.5 Omega; 95% CI 60.2-72.9 Omega) than that using self-adhesive pads (92.1 Omega; 95% CI 81.5-102.7 Omega; 95% CI between the mean =15.8-35.5 Omega; P <0.0001). TTI was significantly less using the manual paddles compared with self-adhesive pads in both AA and AP positions (P <0.0001).


CONCLUSIONS
Despite the subjective difficulties of defibrillating patients in the AP position whilst leaning over them, use of manual paddles achieves a lower TTI than that achieved with self-adhesive pads.
Dodd
Tamsin E L
TE
Shackleton Department of Anaesthetics, Southampton University Hospital NHS Trust, Tremona Road, Southampton SO166YD, UK.
Deakin
Charles D
CD
Petley
Graham W
GW
Clewlow
Frank
F
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004554:Electric Countershock / Q000295:instrumentation* / Q000379:methods; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture