AUSTIN, TEX. – Ultrasound plus real-time transthoracic echocardiography sped up placements of central venous catheters and rule outs of insertion-related pneumothorax, compared with ultrasound alone in a prospective, randomized, controlled study of 60 patients in the medical intensive care unit of a single center.
Compared to conventional ultrasound placement with x-ray confirmation, ultrasound plus transthoracic echocardiography also reduced the time to approval of the line for use, Dr. Dileep Raman reported at the annual meeting of the American College of Chest Physicians.
Waiting for a chest x-ray adds anywhere from 16 minutes to 2 hours to the approval of line use, according to the literature. Ultrasound is “a cheap bedside tool that can be repeatedly used to reduce the amount of chest x-rays for line placement and insertion” and indeed reduced the need for chest x-ray to confirm central venous catheter (CVC) position – without adding to procedure time, he said.
In the study, ultrasound plus transthoracic echocardiography reduced the use of bedside chest x-rays by 57% in 30 patients, compared with conventional ultrasound placement with x-ray confirmation in 29 patients. The mean time to line use was 25 minutes in the ultrasound plus echo group and 53.6 minutes in the conventional placement group, said Dr. Raman of the Cleveland Clinic.
The mean time to complete the procedure was 24.1 minutes in the intervention group, compared with 27.7 minutes in the x-ray confirmation group, he said. None of the study patients had pneumothoraces.
Study subjects were consecutive patients admitted to an intensive care unit at a tertiary care medical center. Both the intervention and control groups had central venous catheters inserted under ultrasound guidance, but the intervention group underwent real-time transthoracic echocardiography to assist in catheter positioning, as well as chest ultrasonography to exclude a pneumothorax. After this process was completed, the line was immediately cleared for use. If the catheter wasn’t detected in the right atrium, the patient was switched to the control group, which was treated using conventional techniques followed by standard chest x-ray.
The study groups were well matched with respect to age, body mass index, and APACHE III score.
Obtaining a chest x-ray to confirm line placement and to exclude pneumothorax remains the standard of care in most ICUs, but Dr. Raman said he and his colleagues dispute that chest x-ray should remain the standard, as it doesn’t identify the superior vena cava–right atrium junction. Also, in addition to reducing the need for chest x-ray, the ultrasound technique seems to give a better picture of line placement.
Additional studies are needed to look at safety and feasibility, because pneumothorax rates are low, and “60 patients is clearly not enough to see if we dented the pneumothorax rate,” he said.
Dr. Raman reported having no disclosures.