TITLE: Is Expired Air Carbon Monoxide Testing Effective for Screening of Cigarette Use in Orthopaedic Patients?
AUTHORS: Sean Sterrenberg, David Gallacher, Melissa Schmidt, Rebecca Rugel, Summer Gerke, Kenneth Gundle, Ryan Wallenberg

[DESCRIPTION]
<div class = "text-blocks"><div class = "text-block"><span style = "font-weight:bold;">Background: </span><span>Tobacco use is associated with increased post-operative complications and is often underreported by patients. Traditional biochemical testing methods, including serum and urine cotinine assays, do not differentiate active smoking from nicotine replacement therapy (NRT). This study intends to evaluate the effectiveness of a novel point-of-care carbon monoxide (CO) breath test to verify smoking status and differentiate active smoking from NRT pre-operatively in a cohort of veteran orthopaedic patients. 

</span></div><div class = "text-block"><span style = "font-weight:bold;">Methods: </span><span>This is a single-institution, prospective cohort study of adult orthopaedic patients at the Portland VA Medical Center to implement and evaluate a point-of-care CO breath test, the Smokerlyzer® Micro EC50, for pre-operative smoking status verification. Patients who are indicated for orthopaedic surgery in the pre-operative clinic will be offered inclusion. Self-reported smoking status will be obtained pre-operatively to categorize patients as non-smoker, quitters, or active smokers. Exhaled CO and serum cotinine levels will be obtained at the initial clinic visit, pre-operative visit, and day of surgery. Primary endpoints are concordance between self-reported smoking status and CO levels, and concordance between exhaled CO and serum cotinine levels.</span></div><div class = "text-block"><span style = "font-weight:bold;">Discussion: </span><span>Pre-operative smoking cessation interventions have been shown to decrease smoking rates on the day of surgery and promote abstinence 30 days post-operatively. NRTs are commonly used to promote smoking cessation, however their effect on surgical outcomes are not known. This study aims to validate the use of point-of-care testing that differentiates active smoking from NRT, and identify patients at risk for smoking status misclassification. Results would provide preliminary data to directly test NRT use, separate from tobacco use, and surgical outcomes.</span></div><div class = "text-block"><span style = "font-weight:bold;">Specific Aims:</span><span style = "font-weight:bold;"> </span></div><div class = "text-block">1. To determine if expired air CO levels can be used to identify patients that are at risk of smoking status misclassification pre-operatively, including patients that are on nicotine replacement therapy. </div><div class = "text-block">2. To evaluate the concordance between self-reported smoking and expired air CO levels in the veteran orthopedic population. </div><div class = "text-block">3. To evaluate the concordance between pre-operative expired air CO and typical serum levels in the orthopedic population. </div><div class = "text-block"><span style = "font-weight:bold;">Hypotheses:</span><span style = "font-weight:bold;"> </span></div><div class = "text-block">1. Expired air CO testing will allow for differentiation between active smokers and those on nicotine replacement therapy compared to serum cotinine testing. </div><div class = "text-block">2. Self-reported “quitters” will have lower agreement between self-reported smoking status and biological testing compared to self-reported “non-smokers” and “active smokers.”</div><div class = "text-block">3. Compared to serum cotinine testing, expired air CO testing will allow for non-inferior accuracy in verifying smoking status. </div></div>

[STEPS]
?. VISIT 1 (the day surgery is decided)The patients fill out a “Tobacco Use Questionnaire.”
Tobacco Use Questionnaire (If you answered yes, complete the questions below, if you answered no, skip to question #2)a. How frequently do you smoke?     i. Daily     ii. Weekly (intermittently)     iii. Monthly (intermittently)     iv. Yearly (rarely)b. When was your last cigarette?     i. Today      ii. In the last 1-2 days     iii. In the past week     iv. In the past monthc. How many cigarettes do you smoke per day?     i. 1-4 per day     ii.      iii. Between ½ pack to 1 pack per day     iv. More than 1 packd. How many years have you smoked daily?     i.      ii. 2-5 years     iii. 5-10 years     iv. >10 years2.  How long ago did you quit smoking?     i. I’ve never smoked     ii.      iii. 2-5 years     iv. >5 years3.  Do you live or work in an environment where you are exposed to second hand smoke?     i. Yes     ii. No4.  Do you use other forms of nicotine?     i. Nicotine replacement therapy (gum, patches)     ii. Cigars (if used greater than weekly)     iii. Other tobacco products (chewing tobacco)     iv. None5. Do you smoke other products that are not cigarettes?     i. Marijuana     ii. Cigars     iii. E-cigarettes     iv. None6. Have you ever been diagnosed with a lung or breathing disease?     i. COPD     ii. Asthma     iii. Obstructive sleep apnea     iv. Other _______________     v. None
?. VISIT 1 (the day surgery is decided)Patient is instructed to perform a breath test using the Smokerlyzer® Micro EC50 device as described per the manufacturer, with the exception that the breath hold is pre-set to only 6 seconds. Results are recorded.
?. VISIT 2 (Pre-operative visit within 4 weeks of surgery)Nursing staff performs venupuncture, and a blood sample is obtained. Serum Nicotine and Serum Cotinine assays are ordered and the sample is sent to the lab. Results automatically are recorded within the electronic medical record system.
?. VISIT 2 (Pre-operative visit within 4 weeks of surgery)Patient is instructed to perform a breath test using the Smokerlyzer® Micro EC50 device as described per the manufacturer, with the exception that the breath hold is pre-set to only 6 seconds. Results are recorded.
?. Visit 3 (Day of surgery)On the day of surgery the patient will undergo a third round of carbon monoxide testing with the Smokerlyzer® Micro EC50 device repeating manufacturer instruction steps 1-15, with the exception that the breath hold is pre-set to only 6 seconds. This testing occurs in the pre-op holding area and is performed by perioperative nursing staff. Results are recorded but are blinded to the surgeon until after the surgery.
?. GENERAL OUTLINEStudy participant recruitment takes place in the orthopaedic clinic and a patient is offered enrollment into the study once the surgeon has indicated them for an orthopaedic surgical procedure.  Upon enrollment, the patient agrees to the following tests on three separate occasions:    1. Visit 1 (The day surgery is decided): The patient will fill out the Tobacco Use Quesionnaire, undergo a blood draw for serum cotinine and serum nicotine assays, and perfrom the exhaled carbon monoxide breath test.    2. Visit 2 (Pre-operative visit within 4 weeks of surgery): The patient will again undergo a blood draw for serum cotinine and serum nicotine assays, and perfrom the exhaled carbon monoxide breath test.    3. Visit 3 (Day of surgery): The patient will perfrom the exhaled carbon monoxide breath test prior to their surgery. These results will be blinded to the surgeon until after the surgery.
?. VISIT 1 (the day surgery is decided)Consent is obtained by a study team member, and the patient is enrolled into the study.
?. VISIT 1 (the day surgery is decided)Nursing staff performs venupuncture, and a blood sample is obtained. Serum Nicotine and Serum Cotinine assays are ordered and the sample is sent to the lab. Results automatically are recorded within the electronic medical record system.