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Three Part Question

In [patients in the emergency department requiring a central line] is [USS guidance better than blind landmark techniques] at [reducing the complications of insertion]?

Clinical Scenario

You are evaluating a 90kg acutely dyspnoeic diabetic woman in the emergency department. She has a history of left ventricular failure and was an inpatient 2 weeks ago with a small myocardial infarction. Her BP is only 90/50 and you feel that she is a high risk patient with poor peripheral venous access who may need high dependency care possibly with inotropes, and you therefore decide that a central line would be of great benefit. Your department has just bought a handheld USS probe and you wonder whether it is worth having a go with this rather than your usual blind landmark technique.

Search Strategy

Medline 1966-07/03 using the OVID interface.
[(exp Ultrasonography/ OR ultrasound.mp) AND (exp Catheterization, Central Venous/ OR central venous catheter.mp OR central line.mp)] LIMIT to Human AND English

Search Outcome

Altogether 349 papers were found of which 2 represented the best evidence. This included a meta-analysis and additional paper. In addition a second meta-analysis not indexed on Medline was identified by cross referencing.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
NICE guidelines, 2002, UK	Systmatic review of the literature 20 RCTs evaluating ultrasound guidance for central line placement found Only 2 were performed in the emergency room setting, with 7 in ITU, and the remainder in elective scenarios Only 4 studies were clearly performed by non anaesthetists	Systematic review and meta analysis	Recommendations	Use of 2-D USS should be considered in most clinical situations where a central line is necessary electively or in an emergency	Grades of recommendation not provided Few studies on non anaesthetist personnel in the emergency department
			Meta-analysis of relative risks of various clinical outcome measures	No. failed catheter placements RR: 0.16 (0.09 – 0.3) No. complications odds: 0.36 (0.17 – 0.36) risk of failure RR: 0.59 (0.39 – 0.88) Number of fewer attempts RR:1.62 (2.57 – 0.67) No. seconds saved 76 (96 – 63) secs No of arterial punctures saved 90 per 1000 patients
			Cost effectiveness	The extra cost is likely to be about £10 patient, although the machines cost £7000-15000 initially
Randolph AG et al, 1996, USA	8 randomised controlled studies identified from Medline search from 1966 to 1995 Studies were using operators with low experience but no studies were in the emergency department	Meta-analysis	Meta-analysis of the relative risk of various clinical variables	Central line placement failure 0.32 (0.18 - 0.55) Complications during catheter placement 0.22 (0.10 - 0.45) Need for multiple catheter placement attempts 0.60 (0.45 - 0.79)	Medline search only, no systematic review Poor search strategy
Miller AH et al, 2002, USA	122 emergency medical patients designated as 'difficult insertions' randomised to the Landmark technique (n=71) or 2-D USS guidance technique (n=51) Difficult patients defined as peripheral vascular disease, coagulopathy, obesity, abnormal anatomy, or history of intravenous drug misuse	Cohort study	Time from needle touching skin to successful flashback	Landmark group 463 secs +/- 627 secs USS group 93secs +/- 176 secs p<0.0001	The insertion time may only represent a small amount of the total time taken to set up an USS guided central line insertion
			Number of attempts	Landmark group 3.54+/-2.7 USS group 1.55+/-1 p<0.0001
			Complications	Landmark group 14% USS group 12% p=0.780

Comment(s)

Two meta-analyses were identified in this area and only 1 additional paper could be found in this area that neither meta-analysis included. Both meta-analyses provide strong evidence that USS guided placement significantly reduces complications during catheter placement, number of attempts at insertion and reduction in the number of attempts at insertion for both neck and femoral line insertion. In addition and the NICE meta-analysis provides evidence that insertion time is quicker although this evidence is less convincing. NICE also imply that if used regularly the cost implication could be as little as £10 per patient although they acknowledge a projected £29 million cost for initial NHS implementation for equipment and training.

Clinical Bottom Line

There is good evidence that USS guided placement of central lines reduces the complication rate associated with this procedure.

References

1. National Institute for Clinical Excellence. Guidance on the use of ultrasound locating devices for placing central venous catheters. Technology appraisal guidance No.49 2002 (Accessed 03/02/03)
2. Randolph AG, Cook DJ, Gonzales CA et al. Ultrasound guidance for placement of central venous catheters: a meta-analysis of the literature. Crit Care Med 1996;24:2053-8.
3. Miller AH, Roth BA, Mills TJ et al. Ultrasound guidance versus the landmark technique for the placement of central venous catheters in the Emergency Department Acad Emerg Med 2002;9:800-5.