Diagnostic Testing
A gloved hand is holding a clinical tube
Spirometry
Peak Flows
Electrocardiograms
Holter Monitor
Echocardiogram
Cardiac Stress Testing
Pulse Oximetry
Capnography
Arterial blood gas (ABG) analysis
Blood gas analyses are performed to evaluate the adequacy of ventilation, oxygenation, oxygen-carrying capacity of the blood and acid-base levels. ABGs are indicated in a number of clinical conditions to:
1. Establish the diagnosis and severity of respiratory failure
2. Manage patients in intensive therapy units admitted for respiratory failure or dysfunction, cardiac failure, renal or hepatic failure, trauma and multi-organ failure, diabetic ketoacidosis, poisoning, sepsis and burns.
Spirometry
Spirometry is a medical screening device that measures various aspects of breathing and lung function. It is performed by using a spirometer, a special device that registers the amount of air a subject inhales or exhales and the rate at which the air is moved into and out of the lungs. Peak Flows
A Peak Flow meter is a portable, inexpensive, hand-held device used to measure how air flows from your lungs in one "fast blast." In other words, the Meter measures your ability to push air out of your lungs. Measurements with a Peak Flow Meter can help you and your doctor monitor and control your asthma.
Electrocardiograms
An electrocardiogram (EKG, ECG) is a test that measures the electrical signals that control the rhythm of your heartbeat. An electrocardiogram may show:
Evidence of heart enlargement.
Evidence of heart enlargement.Signs of insufficient blood flow to the heart.
Signs of a new or previous injury to the heart (heart attack).
Heart rhythm problems (arrhythmias).
Changes in the electrical activity of the heart caused by an electrolyte imbalance in the body.
Signs of inflammation of the sac surrounding the heart (pericarditis).
Holter Monitor
A portable device for continuously monitoring the electrical activity of the heart for 24 hours or more. Its extended recording period is useful for observing occasional cardiac arrhythmias that would be otherwise difficult to identify in a shorter period of time. Also see Holter Monitoring.
Echocardiogram
The echocardiogram is an ultrasound of the heart. The standard echocardiogram is also known as a transthoracic echocardiogram, or TTE. In this case, the echocardiography transducer (or probe) is placed on the chest wall (or thorax) of the subject, and images are taken through the chest wall. Another method to perform an echocardiogram is to insert a specialized scope containing an echocardiography transducer (TOE probe) into the patient's esophagus, and record pictures from there. This is known as a transesophageal echocardiogram, or TEE. The advantages of TEE over TTE are clearer images, since the transducer is closer to the heart.
Cardiac Stress Testing
A cardiac stress test is a medical test performed to evaluate relative arterial blood flow increases to the heart muscles during exercise, as compared to resting blood flow rates. The patient either walks on a treadmill or is given IV medications to "simulate exercise" while connected to an EKG machine, usually the standard 10 connections used to record a 12 lead EKG. Patient symptoms and blood pressure response is repeatedly checked. Using EKG and blood pressure monitoring alone, the test is variously called a cardiac stress test, exercise stress test, exercise treadmill test, stress test or exercise EKG test.
If radioactive isotopes are also used, commonly (technetium Tc99m Sestamibi) and rarely(thallium-201), then it is usually called a nuclear stress test. Nuclear stress tests are extremely accurate in detecting and localizing normal and diseased blood flow to cardiac cells.
Pulse Oximetry
Pulse oximetry is a non-invasive method which allows health care providers to monitor the oxygenation of a patient's blood. A sensor is placed on a relatively thin part of the patient's anatomy, usually a fingertip or earlobe, and red and infrared light is passed from one side to the other. Based upon the ratio of absorption of the red and infrared light caused by the difference in color between oxygen-bound (red) and unbound (blue) hemoglobin in the capillary bed, an approximation of oxygenation can be made.
Carbon dioxide monitoring (Capnography)
End-tidal carbon dioxide monitoring refers to the noninvasive measurement of exhaled carbon dioxide and is most useful when applied directly to patient care. Although commonly used in intubated patients receiving mechanical ventilation, this technique is sometimes used in non-intubated patients. The term "capnometry" refers to the measurement and display of the concentration of exhaled carbon dioxide.
