A Procedure to Standardize Puff Topography During Evaluations of Acute Tobacco or Electronic Cigarette Exposure

Abstract

Introduction Documenting factors that influence differential sensitivity to acutely inhaled nicotine products requires carefully controlling the amount of exposure (dose), and thus a procedure by which to control such exposure. Methods We evaluated consistency of puff volume from intermittent acute exposures to smoked tobacco cigarettes (study 1, n = 45, plus a comparison study of uninstructed use with n = 59) and to vaped electronic cigarettes (e-cigarettes; study 2, n = 27 naive to e-cigarettes) in adult-dependent smokers. All in primary studies 1 and 2 participated in research administering different nicotine levels in each product under blind conditions, one per session using within-subject designs. In both studies, participants followed an automated instructional procedure on a computer monitor standardizing the timing and amount of exposure to each product during a given trial, with four trials per session, each separated by 20 minutes. Puff volume per trial via Clinical Research Support System (CReSS) was the primary dependent measure to determine consistency across trials via intraclass correlation coefficients (ICCs). Results Control over topography with both inhaled products was demonstrated by highly significant ICCs for puff volume across trials. Instructed control with own brand was generally better in study 1 than with uninstructed smoking in the comparison sample, as expected. As intended, reliability of puff volume generally did not differ by menthol preference or sex in either study, but ICCs in study 2 tended to be lower for some men using the placebo e-cigarette. Conclusions This instructional procedure may substantially improve control over amounts of acute exposure to tobacco or e-cigarette use. Implications Control over topography in studies of acute exposure to these inhaled products can potentially aid validity of research into differential sensitivity to use, so findings can be attributed to factors of interest and not to variable exposure. Our procedure minimized variability in exposure to the same product and between moderate nicotine products, but remaining differences suggest that compensation for very low or no nicotine commercial products may be difficult to totally eliminate with these instructions alone. Further study is needed to determine this procedure’s utility with other inhaled products among experienced users and when comparing different products in between-groups analyses.

Research on Behavioral Discrimination of Nicotine May Inform FDA Policy on Setting a Maximum Nicotine Content in Cigarettes

“…32 To ensure the same controlled smoke exposure from each cigarette, timing and duration of each puff was controlled by computer-displayed instructions. 33 This pattern of exposure allowed intervals of 15 minutes between trials while minimizing smoking satiation or toxicity. Total exposure over each 2-1/2 hour discrimination testing procedure was 40 puffs, or about four full cigarettes, under deprived conditions after overnight abstinence, with 20 puffs from the ultra-low and 20 from the other Spectrum cigarettes, nearly all of which were lower in nicotine than commercial brands.…”

Electronic Cigarette Vaping Did Not Enhance the Neural Process of Working Memory for Regular Cigarette Smokers

“…Although most participants in this study were naïve to e-cigs, the degree of liking and/or familiarity with the e-cigs that we prepared would be a confounding factor. In this context, previous research demonstrated that the e-cigs flavor has impacted to reduce cigarette use and quit smoking (Yang et al, 2020); the flavor to e-cigs was highly associated with nicotine consumption (Patten et al, 2021); and the administration of puff inhalation, breath-hold, and exhalation may increase control over amounts of acute exposure to cigarette use (Perkins and Karelitz, 2020). However, Perkins and Karelitz reported that the number of puffs and the duration of puff were different between instructed and uninstructed procedures (Perkins and Karelitz, 2020); it is possible that the smoking craving may not be completely satiated.…”

Acute nicotine reinforcement requires ability to discriminate the stimulus effects of nicotine.

“…We further controlled nicotine dosing with Spectrum by using our validated and reliable puffing procedure, which instructs participants on precisely when and for how long to take each puff to target intake at 60 ml per puff (typical of that during ad lib puffing). That procedure carefully standardizes intake from smoking, as well as from vaping e-cigarettes (Perkins & Karelitz, 2020b).…”