NICE central line guidelines. Dr James Hayward Princess Royal Hospital – Journal Club

NICE Guidelines Issued 2002. Reviewed 2005 2-D imaging ultrasound guidance should be the preferred method when inserting of central venous catheter into the internal jugular vein in adults and children in ‘elective situations’. 2-D imaging ultrasound guidance should be considered in most clinical situations where CVC insertion is necessary, whether the situation is elective or an emergency. Everyone who uses 2-D imaging ultrasound guidance to insert central venous catheters should have appropriate training to ensure they are competent to use the technique.  Audio-guided Doppler ultrasound guidance is not recommended for use when inserting central venous catheters Reviewed 2005 No further evidence – guidance closed.

Background Estimated that 200,000 CVCs per year. Traditional landmark approach anticipating the path of the central vein based on predicted anatomical relationships. Failure rates in have been reported to be as high as 35% Complications Arterial puncture, pneumothorax, air embolus, damage to related structures Operator, patient and situational factors

Technology Real time US enables the operator to visualize the target vein and the surrounding structures before and during the insertion Easily portable US devices producing real-time grey-scale images can be used in a variety of contexts The importance of training is emphasized http://www.youtube.com/watch?v=z2wJCDyePPk

Landmarks

NICE Evidence 20 RCTs 6 compared Doppler guided with landmark 13 compared 2D guidance with landmark 1 compared both 15 looked at IJV 4 looked at SV 1 looked at FV 1 didn’t state

NICE evidence - Operators 7 involved only anaesthetists 4 involved other medical staff 1 involved only junior radiologists 9 did not specify 8 described the operators as being at least 5yrs experience 6 described the operators as having no more than 5yrs experience 6 did not specify

Results 2-D imaging Pooled results suggested that 2D placement was significantly better than landmark placement. First attempt failure (41% reduction in relative risk. CI 12%-61% p<0.009) Total number of attempts (Average reduction of 1.5 attempts. CI 0.47 to 2.53 p=0.004) Absolute failed placement (86% in relative risk. CI 67%-94% p<0.001) Complications (57% reduction in relative risk. CI 67%-94% p<0.001) Some evidence to suggest that using ultrasound resulted in a shorter interval to successful placement.

Cost effectiveness No studies reporting the costs, so NICE developed an economic analysis comparing the cost of 2-D US compared with the landmark method. Theoretical cohort of 1000 patients having IJV cannulation Results suggested that US guidance might reduce the incidence of arterial puncture by 90 per 1000 and would reduce cost by £2 per patient. Most powerful predictor of cost effectiveness is the useage of the ultrasound scanner – less than 11 times per week made it cost ineffective. Scanners are between £5000 £15000 for a scanner and the additional disposables are around £1 per patient

Comments Patient factors Operator training Machine servicing De-skilling juniors from the landmark technique

Study BJA November 2007 “Effect of implementation of NICE guidelines for ultrasound guidance on the complication rate associated with central venous catheter placement in patients presenting for routine surgery in a tertiary referral centre.”

Design Royal Marsden Hospital Ongoing CVC audit since February 2005 Guidelines implemented in October 2005 Prospective audit All patients older than 18yrs between October 2005 and November 2006 who required a central line as part of their anaesthetic were included Acknowledgement that this was a heterogenous group of patients with advanced malignancy and who often had risk factors for difficult cannulation SpRs and Consultants Individual preference for US / landmark CXR post insertion

Results (1) 284 insertions in total 169 under US 115 landmark Implementation of the NICE guidelines was successful 12.5% under US prior to October 2005 59.5% after October 2005 No change in distribution SpRs vs Cons

Results (2) No quoted proportion of subgroup performing landmark/US   Before Implementation After Implementation Total 152 284 Consultant 64 (42.1%) 126 (44.4%) SpR 88 (57.9%) 158 (55.6%) Ultrasound uptake 19 (12.5%) 169 (59.5%) Complications 16 (10.5%) 13 (4.6%) No quoted proportion of subgroup performing landmark/US

Results (2) Over the period of the study the uptake of US increased markedly:

Results (2) Pre guidelines complications occurred in 19/152 (12.5%) Of these 18 were in the landmark group Post guidelines complications occurred in 13/286 (4.6%) Of these 10 were in the landmark group This represents an absolute risk reduction of 6.9%in favour of US (95% CI 1.4% -12.4%)

Results (3) The greatest positive effect of US is for the registrars SpR: 12.3% vs 1.1% Cons: 4% vs 2.6% Significantly greater number of absolute failures in the landmark group 7/115 vs 1/169 in the US group Other complication rates suggested a difference but failed to reach significance

Discussion Increasing evidence that US guidance reduces complications, time, cost-effectiveness, and possibly even line-related sepsis. Use of ultrasound significantly reduced complication rate in-line with NICE evidence

Discussion (2) Initial reluctance to use US with an ultimate usage of approx 80% Generalized reluctance among consultant anaesthetists to use US – recent study showing only 15% Most frequently saying it was unnecessary Training began at the point of guideline implementation Consultants took one day course and then taught others Is this a fair point to commence the comparison? Registrars benefit the most from US Repeat audit data is needed

MCQ 1 Regarding central venous cannulation: The Seldinger technique depends on the passage of the cannula over the needle. False – it depends on the cannula being slid over a wire previously inserted through a needle The internal jugular vein is accessible by a needle inserted at the level of C6 aimed towards the contralateral nipple False – aim towards the ipsilateral nipple. The right sided approach avoids the risk of traumatising the thoracic duct True – unless you are very bad. Pneumothorax is a hazard of the subclavian approach. True – it is a hazard of all upper body approaches. The femoral vein lies lateral to the artery False – Nerve Artery Vein Y-front.

MCQ 2 With regard to air embolism Venous air embolism causes a rise in end-tidal CO2 False – there is a fall in end tidal CO2 Doppler ultrasonography is more sensitive than end-tidal CO2 at detecting air embolism True - a precordial Doppler is very sensitive at detecting even small amounts of air Transoesophageal echo is more sensitive at detecting paradoxical air embolus than Doppler True – this is the only way of detecting paradoxical air embolism but it requries constant visual attention and skill Clinical problems are not likely to be significant until the amount of air exceeds 3mls/kg False – 0.5 to 1mls/kg The volume is increased by nitrous oxide. True – inhalation of 50% nitrous can increase the volume by 200%