Modify What’s Modifiable: Smoking, Obesity, Opioid Dependence, and Nutritional Deficiencies

Risks

Studies have shown that exposure to nicotine and cigarette smoke decreases cutaneous blood flow. The nicotine and carbon monoxide from cigarettes can also hinder cell proliferation and epithelial regeneration. Prospective human trials have suggested that collagen synthesis in patients who smoke more than a pack of cigarettes a day was lower than the collagen synthesis in matched nonsmoking patients. Collagen is a major determinant of tensile strength in healing wounds and thus is an essential factor to consider in the recovery of postoperative joint replacement patients. Because of that, smoking may lead to higher rates of postoperative wound infections.

Effects of Cotinine

Nicotine has several metabolites. The primary one is cotinine, a breakdown product found in the blood, saliva, and urine of smokers. Cotinine is the most commonly used biomarker to test for tobacco exposure and therefore can be used by healthcare providers to test for tobacco usage before total joint arthroplasty procedures. This test can also be used to encourage patients who are smokers to quit by aiding them in monitoring and tracking their smoking consumption.

Cotinine has a half-life of approximately 20 hours and is available as a blood test. Testing cotinine levels before surgical joint procedures can be an effective method to screen for compliance with smoking cessation. Serum cotinine levels of lower than 10 ng/mL should be used as a cutoff consistent with not smoking. However, it is also important to note that these levels vary with race, age, and sex. It is essential to monitor cotinine levels to assess smoking status. It is important to continue to study the relationship between cotinine levels and potential postoperative complications.

Complications

Studies evaluating postoperative outcomes of patients who smoke have demonstrated that smoking can lead to an increase in hospital length of stay, an increase in intensive care unit admissions, greater rates of wound complications, and increased incidence of perioperative joint infections. Metaanalysis studies in rheumatology have evaluated the effects of smoking on total joint arthroplasty. This research has suggested that both current and former smokers are at increased risk for development of complications compared with nonsmokers. These complications include higher rates of reoperation, revision, implant loosening, deep infection, skin necrosis, and mortality ( Fig. 2.1 ).

Cessation

Research has suggested that cessation of smoking before knee arthroplasty surgery can lessen the risk of postoperative infection. Clinical outcome studies have shown that after 4 to 6 weeks of tobacco cessation, metabolic and immune functions begin to recover and normalize. Other studies have suggested that patients who quit tobacco use 4 to 8 weeks before surgery have decreased morbidity and mortality rates compared with current smokers. Although some literature suggests that smoking cessation 4 to 6 weeks before joint arthroplasty surgery can lessen the risks posed by nicotine and other byproducts of smoking, current and former smokers are at greater risk for perioperative complications in comparison with patients who have never smoked.

Smoking cessation is essential for proper wound healing and lowering rates of postoperative complications. Despite targeted efforts to aid patients in stopping smoking before surgery, more than 7% of patients are unsuccessful. An additional 55% of patients who do stop smoking before surgery are unsuccessful in maintaining this cessation 8 years after surgery.

For some patients, especially older adults, the anticipation of surgery itself can serve as a motivating factor for risk-reducing behavioral change and can increase the likelihood of smoking cessation. The need for surgery as a life-improving measure may be the first time a patient seriously considers pursuing an avenue for smoking cessation. Furthermore, smoking cessation for surgery can often serve as a start for long-term smoking cessation. In a study on smoking cessation programs before total joint arthroplasty it was found that 35% (13/37) of patients who quit smoking before surgery were still abstinent 1 year postsurgery.

Total joint arthroplasties have the potential to provide smoking patients with goal-oriented motivation to quit smoking and remain abstinent. For this reason, it is crucial for members of the healthcare team to provide resources, both before and after surgical procedures, to patients who smoke to aid them in establishing and maintaining their smoking cessation. These resources include counseling, pharmacotherapy, acupuncture, hypnosis, or a combination of these therapies. Helping all patients achieve these healthy changes has the potential to drastically improve individual patient outcomes and decrease large-scale risks of complications.