Dr. Schiffman received his B.S. degree with High Honors in biology from Hobart College in 1976. He then moved to Chicago where he studied biochemistry at the University of Illinois, Chicago Circle. He attended Rush Medical College where he received his M.D. degree in 1982 and was elected to the Alpha Omega Alpha Medical Honor Society. He completed his Internal Medicine internship and residency at the University of California, Irvine.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Oximetry is a procedure for measuring the concentration of oxygen in the blood. The test is used in the evaluation of various medical conditions that affect the function of the heart and lungs.
How is oximetry done?
This is done using an oximeter, a photoelectric device specially designed for this purpose. A reusable probe can be placed on the finger or a single use tape probe is placed on the earlobe or finger.
What are pulse oximeters?
The oximeters most commonly used today are called pulse oximeters because they respond only to pulsations, such as those in pulsating capillaries of the area tested.
How common are oximeters?
Oximeters are now a virtual fixture in intensive care units, pulmonary units and elsewhere in hospitals and health care facilities.
How does a pulse oximeter function?
A pulse oximeter works by passing a beam of red and infrared light through a pulsating capillary bed. The ratio of red to infrared blood light transmitted gives a measure of the oxygen saturation of the blood. The oximeter works on the principle that the oxygenated blood is a brighter color of red than the deoxygenated blood, which is more blue-purple. First, the oximeter measures the sum of the intensity of both shades of red, representing the fractions of the blood with and without oxygen. The oximeter detects the pulse, and then subtracts the intensity of color detected when the pulse is absent. The remaining intensity of color represents only the oxygenated red blood. This is displayed on the electronic screen as a percentage of oxygen saturation in the blood.
Are there other types of oximetry?
Yes. Oximetry can also be done on blood that is within the heart (intracardiac oximetry) or on whole blood that has been removed from the body. More recently, using a similar technology to oxymetry, carbon dioxide levels can be measured at the skin as well.
COPD (chronic obstructive pulmonary disease) is a disorder that persistently obstructs bronchial airflow. COPD mainly involves three related conditions, chronic bronchitis, chronic asthma, and emphysema. Symptoms of COPD include chronic cough, shortness of breath, frequent respiratory infections, wheezing, morning headaches, and pulmonary hypertension. Treatment of COPD is focused on the related condition(s).
Emphysema is a progressive disease of the lungs. The primary cause of emphysema is smoking. Alpha 1-antitrypsin deficiency is a rare disorder that has a genetic predisposition to emphysema. Aging, IV drug use, immune deficiencies, and connect tissue illnesses are also risk factors for emphysema. Emphysema is a subtype of COPD (chronic obstructive pulmonary disease, COLD). Symptoms include shortness of breath and wheezing. Management of symptoms may be achieved with medications, quitting smoking, pulmonary rehabilitation, or surgery.
Premature ventricular contractions (PVCs) are premature heartbeats originating from the ventricles of the heart. PVCs are premature because they occur before the regular heartbeat. There are many causes of premature ventricular contractions to include: heart attack, high blood pressure, congestive heart failure, mitral valve prolapse, hypokalemia, hypoxia, medications, excess caffeine, drug abuse, and myocarditis.
The lungs are primarily responsible for the exchange of oxygen and carbon dioxide between the air we breathe and the blood. Eliminating carbon dioxide from the blood is important, because as it builds up in the blood, headaches, drowsiness, coma, and eventually death may occur. The air we breathe in (inhalation) is warmed, humidified, and cleaned by the nose and the lungs.
Chronic obstructive pulmonary disease (COPD) is comprised primarily of three related conditions - chronic bronchitis,
chronic asthma, and
emphysema. In each condition there is chronic obstruction of the flow of air through the airways and out of the lungs, and the obstruction generally is permanent and may be progressive over time.
While asthma features obstruction to the flow of air out of the lungs, usually, the obstruction is reversible. Between "attacks" of asthma the flow of air through the airways typically is normal. These patients do not have COPD. However, if asthma is left untreated, the chronic inflammation associated with this disease can cause the airway obstruction to become fixed. That is, between attacks, the asthmatic patient may then have abnormal air flow. This process is referred to as lung remodeling. These asthma patients with a fixed component of airway obstruction are also considered to have COPD.