Foam test should be done in the following cases:
A list of cases:
1, patients with ischemic stroke or transient ischemic attack whose cause cannot be found by routine examination, especially young stroke patients; patients with suspected cardiogenic embolic disease;
2, patients with migraine headache, especially those with aura
3, patients with unexplained syncope;
4, patients with diving decompression sickness;
5, patients with potential arterial-arterial embolic source disease;
6, patients with vascular examination or interventional therapy;
7, pre-service medical examination for divers and astronauts.
Second, the principle of foaming test:
The principle of foaming test is transthoracic echocardiography acoustic imaging, with the help of TCD embolus detection and analysis system, in the patient at rest and the standard Valsalva maneuver (deep inhalation and then hold the breath, and then forceful exhalation), the use of injectable hand-vibrating physiological saline as a reinforcing agent.
The number of microemboli (air emboli) in the cerebral vasculature, mainly in the bilateral cerebral arteries, is examined to detect right-to-left cardiac shunts and pulmonary arteriovenous shunts, and to diagnose the presence of patent foramen ovale in the patient.
(Transcranial Doppler ultrasound, TCD) is a noninvasive test for evaluating the hemodynamics of arteries in the base of the skull by using the naturally weak areas of the human skull as acoustic windows for detection (e.g., the jagged part of the temporal bone, the foramen magnum of the occipital bone, and the orbital sockets).
Introduction of foaming experiment and experimental process
I. Introduction of foaming experiment:
Foaming experiment is mainly to check some cardiography, cardiac ultrasound to check the condition, foaming experiment is mainly to check the patient under the ultrasound, which can be checked out the left and right shunt of the heart and the shunt of the pulmonary artery.
According to the results of the doctor's examination to do some conditioning, if there is a physical abnormality, you can under the guidance of the doctor to take some oral medication to regulate.
Second, the experimental process:
1. A venous access is opened in the patient's elbow vein, and the patient lies flat on the bed. The doctor puts the TCD probe on the patient's temporal window or other detection windows to monitor the cerebrovascular (commonly used middle cerebral artery) blood flow, adjusts the relevant parameters and fixes them.
2. Take a syringe to extract 9ml of saline, and then extract 1ml of gas, through the tee connected to the arm of the venous access, back to draw a drop of blood, and then take an empty syringe is also connected to the tee, and then the two syringes back and forth to pump and push to make the bubble suspension, the production of the bubble suspension will be made intravenous injection.
With the help of TCD embolus monitoring and analyzing system, observe the operation of the tiny bubbles into the human vein. The above maneuver was done once while the patient was breathing calmly, and the Valsalva maneuver (holding the breath under deep inhalation and then exhaling forcefully) was repeated two to three times.
3. The entire procedure takes about 20 minutes. If there is an abnormal right-to-left shunt in the heart or pulmonary artery, the microembolic signal enters the left heart and body circulatory system through the shunt, which can be monitored by Doppler in the cerebral arteries to diagnose a right-to-left shunt.