Purpose: To determine luminance and light field characteristics and the effect of residual battery potential and luminance on light colour temperature in our used Macintosh #3 and #4 fibre-light (FLB) and bulb-light (BLB) laryngoscopes. Methods: We used a power supply to provide laryngoscopes with potentials equivalent to those most commonly measured in the handles in use in our OR. Measurements were made under controlled, constant, conditions using a Pentax digital spotmeter (luminance) or a Minolta Color III colour temperature meter (light colour). Colour measurements were made while increasing the power source potential from 2-3 volts (v) in increments of 0. I v. Light field measurements were made with amm increment ruler mounted on the base of the test fixture. Results: At 2.5 and 2.8 v respectively, the #3 FLB produced luminance values of 23.9 ___ 11.4 and 41.7 _+ 17.2 cd-m -2 (mean ___ SD), and the #4 FL8 produced 58.6 _+ 21.4 and 90.9 __+ 32.2 cd'm -2. Increasing potential increased luminance values (P < 0.001) and the #4FLB produced higher luminance values (P < 0.001). BLB produced higher luminance values than did FLB across all comparisons (P < 0.001). As potentials and luminance values decreased, light temperature was reduced (P < 0.001). There were no differences in light field dimensions noted in any comparison. Conclusion: Fifteen percent of the BLB did not meet the minimum luminance for laryngoscopy of I00 cd.m -2, 92% of the FLB did not meet that same standard. ObjrD&erminer les caract&istiques de la luminance et du champ lumineux, ainsi que l'effet de la luminance et de l'~nergie de la pile r&iduels sur la thermocolorim&rie des laryngoscopes Macintosh n ~ 3 et 4 avec fibre optique (LFO) et ampoule (LA). M~thode : Nous avons utilisE une alimentation Electrique pour foumir aux laryngoscopes l'Energie ~quivalente celle qui est la plus communEment utilisEe dans les appareils en usage dans nos salles d'opEration. Les mesures ont EtE faites dans des conditions contr61&s et constantes ~ l'aide d'un photom&re digital Pentax (luminance) ou d'un thermocolorimEtre Minolta Color III (couleur de la lumiEre), l'enregistrement des couleurs a &E rEalis~ tout en augmentant le potentiel de la source EnergEtique de 2-3 volts (v) par increments de 0, I v. Les mesures du champ lumineux ont EtE obtenues avec une r~gle millim&rique montEe sur la base de l'appareil test& R~,sultats : ik 2,5 et 2,8 v respectivement, le LFO n ~ 3 a produit une luminance de 23,9 __. 11,4 et 41,7 ___ 17,2 cd-m -2 (moyenne __+ Ecart type), et le LFO n ~ 4 a produit une luminance de 58,6 --+ 21,4 et 90,9 --+ 32,2 cd'm -2. l'augmentation de potentiel EnergEtique a entra~nE une hausse de la luminance (P < 0,00 I) et le LFO n ~ 4 a produit une luminance plus importante (P < 0,00 I). Le LA a produit des valeurs de luminance plus Elev&s que le LFO pour toutes les comparaisons rEalisEes (P < 0,00 I). La temperature lumineuse a baissE en accord avec les diminutions d'Energie et de luminance (P < 0,001). Aucune difference de dimensions des champs lum...

Applying force to self-adhesive electrodes reduces TTI and should be considered as a means of improving ECV success. Numerically greater mean force applied with a "push-up" force analogy suggests that "concrete" cues may be useful in improving ECV technique.

Electrical cardioversion is commonly performed to restore sinus rhythm in patients with atrial fibrillation (AF), but it is unsuccessful in 10-12% of attempts. We sought to evaluate the effectiveness and safety of a novel cardioversion protocol for this arrhythmia.

Background The relevance of transthoracic impedance (TTI) to electrical cardioversion (ECV) success for atrial tachyarrhythmias when using biphasic waveform defibrillators is unknown. Hypothesis TTI is predictive of ECV success with contemporary defibrillators. Methods De‐identified data stored in biphasic defibrillator memory cards from ECV attempts for atrial fibrillation (AF) or atrial flutter (AFL) over a 2‐year period at our center were evaluated. ECV success, defined as arrhythmia termination and ≥ 1 sinus beat, was adjudicated by 2 blinded cardiac electrophysiologists. The association between TTI and ECV success was assessed via Cochrane‐Armitage trend and Spearman rank correlation tests, as well as simple and multivariable logistic regression. The influence of TTI on the number of shocks and on cumulative energy delivered per patient was also examined. Results 703 patients (593 with AF, 110 with AFL) receiving 1055 shocks were included. Last shock success was achieved in 88.0% and 98.2% of patients with AF and AFL, respectively. In patients with AF, TTI was positively associated with last shock failure (Ptrend =0.019), the need for multiple shocks (Ptrend <0.001), and cumulative energy delivered (ρ = 0.348; P < 0.001). After adjusting for first shock energy, 10‐Ω increments in TTI were associated with odds ratios of 1.36 (95% CI: 1.24–1.49) and 1.22 (95% CI: 1.09–1.37) for first and last shock failure, respectively (P < 0.001 for both). Conclusions Although contemporary defibrillators are designed to compensate for TTI, this variable continues to be associated with ECV failure in patients with AF. Strategies to lower TTI during ECV for AF may improve procedural success.