Study designs of evaluations included in the review
Only randomised controlled trials (RCTs) and quasi-RCTs were considered for the review.
Specific interventions included in the review
Comparisons of the use of real time ultrasound (using an external probe or Doppler ultrasound) with the use of traditional landmark techniques alone to place CVCs were considered in this review. Eleven of the included studies used Doppler ultrasound and 13 used external ultrasound.
Participants included in the review
Any patient group that required placement of a CVC was eligible. The included studies were of medical-surgical patients, intensive care unit patients, adult cardiothoracic surgery patients, paediatric cardiac surgery patients, dialysis, apheresis or total parenteral nutrition patients, cardiac catheterisation patients, chemotherapy patients, post-cardiac arrest patients, and an unspecified population in one study.
Outcomes assessed in the review
The outcomes specified in the inclusion criteria were time to catheter placement, number of attempts, number of successes at first attempt and failure to place catheter. Complications were also recorded.
How were decisions on the relevance of primary studies made?
The author does not state how the papers were selected for the review, or how many of the reviewers performed the selection.