E-Cigarette study reveals how nicotine hits the bloodstream

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Above 21 years of age * Use ENDS at least 3 months and at least 3 times a week. * Be willing to provide informed consent, attend the lab, and abstain from tobacco/nicotine as required. * Have a normal Allen test Exclusion Criteria: * Any significant current medical condition such as neurological, cardiovascular, endocrine, renal, or hepatic pathology that would increase risk or would interfere with/mimic tobacco abstinence * Untreated, unresolved active pulmonary or cardiovascular conditions (i.e. chest pain, dyspnea, acute infection, recurring bronchitis, and reactive airway disorder) * Breast-feeding or Pregnant (by urinalysis at screening). * Vaping less than 3 months and less than 3 times per week * Taking anticoagulants and blood thinners * Known hypersensitivity to propylene glycol * History of environmental - bronchospastic allergies, multiple chemical sensitivities, or other airway sensitivities that require the use of an epi pen or that in the investigator's view would make it risky for participation. * Has current symptoms as identified by the Health Assessment Checklist including cough, shortness of breath, chest pain, nausea, vomiting, stomach pain, diarrhea, fever, chills, or weight loss * Participants intending to quit tobacco/nicotine use in the next 30 days will be excluded and referred to cessation treatment. * Abnormal Allen Test (impaired collateral circulation) * Positive pregnancy test at any study visit * Infection of skin or soft tissue at insertion site (erythema, swelling, ulceration) * Peripheral vascular disease * Coronary artery disease/advance atherosclerosis * Raynaud's phenomenon * Coagulopathy (hereditary bleeding disorders, advanced liver disease) * Thromboangiitis obliterans * COPD/emphysema/chronic bronchitis * Allergy to lidocaine or anesthetics * Inability to tolerate blood draws for any reason * Additional Screening Procedures: Significant changes and/or abnormalities in these assessments during the study period may warrant exclusion at the discretion of the PI. * Participants will be asked to answer the 4-item Patient-Reported Outcomes Measurement Information System (PROMIS) physical function scale and will be excluded if they report greater than "without any difficulty" on any single item as a screening tool * Spirometry (baseline and before each visit) * Physical Exam * Application of the self-reported signs and symptoms health questionnaire with exclusion of those with chronic symptoms that would interfere with monitoring of vaping complications (baseline and \* before each visit). Participants will be excluded and referred for medical treatment if they indicate dyspnea or cough symptoms are "severe." * PROMIS Dyspnea Severity Item Pool * PROMIS Dyspnea Characteristics * PROMIS Fatigue Short Form * Functional Assessment of Chronic Illness Therapy (FACIT) Cough item