standard-sized cigarette-like ECs, while experienced EC users ("vapers") often use models that are larger than a cigarette and house higher voltage or longer life batteries (Foulds, Veldheer, & Berg, 2011). Furthermore, EC and tobacco cigarette puffing characteristics may differ, suggesting that inexperienced users may not use ECs in a manner that allows for sufficient nicotine delivery (Trtchounian et al., 2011). Whether user experience and/or device characteristics influence nicotine delivery is unknown. The purpose of the present study was to characterize the nicotine delivery profile, subjective, and cardiovascular effects of ECs in experienced ECs users who were using their preferred devices.
Methods
Eight EC users (3 women; 8 Caucasian) consented to and completed this single-session (5 hr) Institutional Review Board-approved protocol. Participants used their own fully charged EC, and a prefilled cartomizer (heater + liquid) of their chosen flavor/nicotine content was provided. At the start of the session, participants were surveyed regarding health, demographics, and EC use habits. Participants were included in the study if they reported using an EC for at least 3 months, used at least 2-3 ml of nicotine solution or two cartridges per day, used nicotine solution of at least 10 mg/ml nicotine, smoked fewer than five cigarettes per day, and were between the ages of 18 and 55. Participants were excluded if they reported any chronic health or psychiatric conditions, had a history of high or low blood pressure, or were unwilling to use a cartridge or cartomizer during the session.
Participants were required to abstain from all nicotine and tobacco product use, including ECs, for at least 12 hr prior to the session. Abstinence was verified upon arrival at the laboratory by a carbon monoxide level of 10 ppm or less and was further verified later by plasma nicotine levels at or below the limit of quantification (2 ng/ml). At session onset, a venous catheter was inserted into the participant's forearm vein and continuous physiological monitoring commenced. Approximately 55 min