Thanks so much for your constructive, informed input. No, this thread is not a joke. It's supposed to be a serious scientific discussion and a request for help.
Small quantities of air bubbles are routinely injected into central lines during cardiac ultrasound to assess flow.
is an study of the heart
using ultrasound. A bubble echocardiogram is an extension of this that uses simple air bubbles as a contrast medium during this study and often has to be requested specifically. Although colour Doppler can be used to detect abnormal flows between the chambers of the heart (e.g. patent foramen ovale
) it has a limited sensitivity
. When specifically looking for a defect such as this small air bubbles can be used as a contrast medium and injected intravenously, where they travel to the right side of the heart. The test would be positive for an abnormal communication if the bubbles are seen passing into the left side of the heart. (Normally they would exit the heart
through the pulmonary artery
and be stopped by the lungs.) This form of bubble contrast medium is generated on an ad-hoc
basis by the testing clinician by agitating normal saline
(e.g. by rapidly and repeatedly transferring the saline between two connected syringes) immediately prior to injection."
Also, ECG can be used to detect CVP catheter position, although this is probably not a desirable method.
From the Annals of Surgery, 1986:
"In an attempt to improve the accuracy of central venous pressure (CVP) catheter tip location, 84 consecutive cardiac surgery patients in sinus rhythm were studied prospectively with respect to subclavian insertion of a CVP catheter using a guidewire technique. The presence of cardiac arrhythmia was used as an index of right atrial (RA) location of the guidewire tip, before threading the catheter over the guidewire. Correct catheter tip location (superior vena cava [SVC] or RA) was achieved in 100% of patients (N = 78) with premature atrial contractions (PACs) related to guidewire insertion. This fell to 50% (N = 4) if no arrhythmias were noted from the guidewire. Ventricular arrhythmias were noted in two of 84 patients (2.4%). Other problems related to the use of this technique are discussed."
Quote from sunnycalifRN
Never heard of either. You're joking about injecting air, aren't you?