Clinlab Navigator

Cotinine

More than 45 million Americans or 19% of the adult population still smoke tobacco. Tobacco smoke is a complex mixture of compounds including nicotine, carbon monoxide, tar, hydrogen cyanide, nitrogen oxides, N-nitrosamines, formaldehyde, and benzene. Nicotine is an addictive substance that causes individuals to continue using tobacco despite concerted efforts to quit. Smoking is a risk factor for cancer, cardiovascular disease, and pulmonary disease and is the leading cause of preventable death in the United States.

Smoking is also associated with adverse surgical outcomes including impaired wound healing, wound dehiscence, incisional hernia formation, surgical site infection and pulmonary complications. Several mechanisms are responsible for the detrimental effect of smoking on wound healing including vasoconstriction, tissue ischemia, thrombosis, reduced inflammatory response, impaired bactericidal activity and alterations of collagen metabolism. Tissue flaps, which have a fragile blood supply, are particularly vulnerable to these smoking-induced reductions in blood flow.

Studies have shown that patients tend to lie about smoking, with approximately 25% of self-reported nonsmokers testing positive for nicotine metabolites and 50% of smokers under-reporting the amount they smoke. Smoking can be detected by measurement of nicotine metabolites in a random urine specimen. Urine testing can also be used to monitor compliance of individuals engaged in smoking cessation programs.

CDC recommends that surgical patients stop smoking for 4 weeks prior to surgery.

Plastic surgeons and some other specialties have begun testing patients for smoking who are at high risk for surgical complications. Typically, patients are tested during their initial office visit and instructed to quit smoking before surgery. They are retested on the day of surgery. Individuals who test positive may have their surgery canceled.

Nicotine has a very short elimination half-life of 2 hours because it is rapidly metabolized in the liver to cotinine. Cotinine can be detected in urine up to 3 days after nicotine use, using a detection cutoff of 200 ng/mL. Because of its longer window of detection, cotinine is the best biomarker of smoking.

Preoperative testing can be performed with a rapid point of care test for urine cotinine. Quantitative confirmatory testing for nicotine and its metabolites can be sent to a reference laboratory if confirmatory testing is requested.  Specimen requirement is a random urine collected on the day of surgery.

AddThis Social Bookmark Button