Table 5
Author, date and countryPatient groupStudy type (level of evidence)OutcomesKey resultsStudy weaknesses
Randolph AG et al, 1996, USAEight randomised controlled studies identified from Medline search from 1966 to 1995Meta-analysisMeta-analysis of the relative risk of various clinical variablesCentral line placement failure 0.32 (0.18 to 0.55)Medline search only, no systematic review
Studies were using operators with low experience but no studies were in the emergency departmentComplications during catheter placement 0.22 (0.10 to 0.45)Poor search strategy
Need for multiple catheter placement attempts 0.60 (0.45 to 0.79)
NICE guidelines, 2002, UKSystematic review of the literatureSystematic review and meta analysisRecommendationsUse of 2-D USS should be considered in most clinical situations where a central line is necessary electively or in an emergencyGrades of recommendation not provided
20 RCTs evaluating ultrasound guidance for central line placement foundMeta-analysis of relative risks of various clinical outcome measuresNo. failed catheter placements RR: 0.16 (0.09 to 0.3)Few studies on non-anaesthetist personnel in the Emergency department
No. complications odds: 0.36 (0.17 to 0.36) risk of failure RR: 0.59 (0.39 to 0.88)
Only two were performed in the emergency room setting, with seven in ITU, and the remainder in elective scenariosNumber of fewer attempts RR 1.62 (2.57 to 0.67)
Number of seconds saved 76 (96–63)
Number of arterial punctures saved 90 per 1000 patients
Only four studies were clearly performed by non-anaesthetistsCost effectivenessThe extra cost is likely to be about £10 patient, although the machines cost £7000–£15000 initially
Miller AH et al, 2002, USA122 emergency medical patients designated as “difficult insertions” randomised to the Landmark technique (n = 71) or 2-D USS guidance technique (n = 51)Cohort studyTime from needle touching skin to successful flashbackLandmark group 463 s +/−627 s SS group 93 s +/−176 s p<0.0001The insertion time may only represent a small amount of the total time taken to set up an USS guided central line insertion
Difficult patients defined as peripheral vascular disease, coagulopathy, obesity, abnormal anatomy, or history of intravenous drug misuseNumber of attemptsLandmark group 3.54 +/−2.7 USS group 1.55 +/−1 p<0.0001
ComplicationsLandmark group 14% USS group 12% p = 0.780