Sleep and Cardio-Pulmonary Evaluations
You are undergoing general anesthesia and abdominal surgery. Obesity decreases pulmonary function and we need to determine if your impairment increases your risk for operative or post-operative complications. We also need to determine if you have pulmonary problems that are not known to you or your physician. The pulmonary testing consists of spirometry, which measures your functional lung capacity (Vital Capacity) and also the behavior of your airways (bronchial tubes) and their ability to allow air movement in and out of the lungs. This test may uncover lung or airway problems that you have as a result of your excess weight, asthma or cigarette smoking. If there are abnormalities that seem greater that expected, we will suggest additional lung function testing.
Why do we do comprehensive exercise testing?
Comprehensive Exercise Testing is the best measure of your heart (cardiac) function and “cardiac reserve”. Exercise (or stress testing) brings out abnormalities in heart function which might not be evident during resting conditions. Anesthesia and surgery are stresses that can sometimes surprise physicians (and patients) by unmasking silent heart disease. Unsuspected heart disease is the greatest risk for serious complications of a surgical procedure. Exercise tests on an obese patient can be challenging because it is difficult to know precisely what is normal for the individual. The problem is solved by doing comprehensive metabolic exercise testing which also helps us sort out lung problems, heart problems, and problems due to excess body weight. The results can also help us guide you with regards to your exercise program.
Comprehensive metabolic exercise testing measures your exercise capacity while pedaling a bicycle. It is all done non-invasively. We do not need to draw blood. We preferentially use a bicycle because it is the most manageable exercise for obese patients and allows us to increase the intensity of the exercise very gradually. During exercise you will be wearing a mask (rather than a mouthpiece and a nose-clip) so you are able to talk and swallow during exercise. This allows us to measure your oxygen uptake, your carbon dioxide output, and the volume of your breathing. During exercise we will continuously monitor your EKG, and the level of oxygen in your blood using a skin sensor.
Why do we do a sleep evaluation?
Obesity certainly increases the risk of sleep apnea which may cause or exacerbate diabetes, and hypertension, and sleep apnea increases the risk of heart attack or stroke. Sleep apnea also increases the risk of post-operative complications. Snoring, acid reflux, hypertension, and fatigue are common complains in the general population, but are also symptoms associated with sleep apnea. If we determine that you have sleep apnea and we initially treat the condition with positive airway pressure prior to your surgery, we decrease your risk of post-operative complications. An overnight sleep study will be done if our clinical evaluation suggests the possibility of sleep apnea. Patients with sleep apnea may have several other sleep disorders, but the overnight sleep study will reveal these as well.
If you have previously undergone a thorough cardiac, pulmonary or sleep evaluation with your personal physician, cardiologist, pulmonologist, or sleep doctor we will review these evaluations with you and decide if any additional testing is necessary.