The Effect of Electronic Cigarettes on Hand Microcirculation.

PURPOSE: Smoking conventional cigarettes reduces peripheral microcirculation leading to worse outcomes after hand surgery. Patients are increasingly using electronic cigarettes (eCigarettes); however, there is no published research investigating the effects of eCigarettes on hand microcirculation. METHODS: Fifteen healthy subjects with a median age of 26 years were recruited: 7 smokers and 8 nonsmokers. A noninvasive O2C laser Doppler probe measured a baseline control reading at deep (7-mm) and superficial (3-mm) levels. Participants commenced a 5-minute smoking protocol of nonnicotine (0-mg) eCigarettes with continuous microcirculation measurements during smoking and for 20 minutes afterward. This was repeated with nicotine (24-mg) eCigarettes. Readings were averaged over 5-minute periods and standardized as a percentage of baseline. A linear mixed-effects model with an unstructured covariance structure was used to analyze the data. RESULTS: Smokers had a statistically significant reduction in hand microcirculation during and up to 20 minutes after smoking a 24-mg eCigarette. There was a maximum reduction of 77% in superficial flow and 29% in deep flow. After smoking a 0-mg eCigarette, smokers demonstrated an increase in superficial flow of up to 70% with no change in deep flow. Nonsmokers had no statistically significant change in superficial or deep flow after smoking either eCigarette. CONCLUSIONS: A 24-mg eCigarette significantly reduced smokers' hand microcirculation during and after smoking. Microcirculation increased in smokers after inhalation of a 0-mg eCigarette. CLINICAL RELEVANCE: We advise smokers undergoing hand surgery to avoid high-dose eCigarettes and, if necessary, to use 0-mg eCigarettes as an alternative.