This document discusses the benefits of ultrasound-guided regional anesthesia. It begins with an introduction to Xavier Paqueron, an anesthesiologist in France. The rest of the document discusses how ultrasound improves the success rate, safety, and efficiency of regional anesthesia compared to nerve stimulation alone. Key points include reduced procedure time and local anesthetic volumes, real-time visualization of needle placement to avoid intraneural injection, and improved learning curve for ultrasound techniques. While ultrasound guidance provides benefits, the document notes mistakes like unintended needle or probe movement can still occur, so vigilance is important when using ultrasound.

1. Xavier Paqueron MD, PhD
Clinical Centre, Angoulême, France
Ultrasound-guided regional anesthesia. :
What do ultrasound bring to regional anesthesia ?
xavier.paqueron@orange.fr

2. Close to Bordeaux and Cognac
Where is , France ?

3. Close to
Cognac
Close
to
Bordeaux
Where is , France ?

4. Private 300 beds Hospital
My Institution : The Clinical Centre
Ambulatory Care Unit
Surgery
• Orthopedic
• Hand
• Urologic
• Vascular
• Abdominal
• Gynecologic
• Breast
• OPH
• ENT
Obstetrics
Pain Clinic
Medicine
• Oncology
• Internal medicine
• Cardiology
• Pneumology
www.centre-clinical.fr/
Regional anesthesia room
PACU

5. Current place of regional anesthesia
① Postoperative pain control
② Improved postoperative recovery
③ Alternative to GA
④ Ambulatory surgery
⑤ PONV
1

6. RA superior to morphine during the 2 first postoperative days
0
2
4
6
8
10
24 Hrs 48 Hrs
catheter
opiates
0
1
2
3
4
24 Hrs 48 Hrs 72 Hrs
catheter
opiates Mean VASMax VAS
Continuous blocks = the reference

7. Recovery - Rehabilitation

8. Alternative to GA
In ambulatory
surgery

9. Post Operative Nausea & Vomiting

10. Cost/effectiveness
Of US-guidance

11. Evidence-based & ultrasound guidance
① Success rate
② Comfort
③ Other benefits
2

12. Evidence-based
Improved
Success
Rate
0
25
50
75
100
Complete sensory block
at 30 min
Successful surgical
anesthesia
Percentatge (%)
NS US US&NS
0
5
10
15
Procedure Bme (min)
Time (minutes)
NS US US&NS
*
* *
P= 0.07
* P< 0.05

13. Success
Rate
Conversion
to
GA or spinal
A Meta-analysis
(Abrahams 2009)

14. Onset time of block
A Meta-analysis
(Abrahams 2009)

15. Casati 2007, Orebaugh 2007
Reduction of number of needle trajectories with USGRA
Perceived pain is less frequent
20 % with USGRA vs 48 % nerve stimulation

16. How USGRA does improve safety ?
① Control of needle tip
② Diagnose early
• intravascular
③ Reduce toxicity
• Reduce volumes
④ Diagnose early
• Intraneural
3

17. Always believe that what you think is the needle tip may not be it
Control of needle tip - Whatever the approach
Always consider you may not see the needle tip

18. Move the probe to see the needle
Tissue movements / needle
AssociaIon with nerve sImulaIon
HydrolocaIon
THE Obsession - Know where the needle tip is

19. Diagnose Early
Intravascular injection
Look here !

20. Systemic toxicity
Case reports
2007
2008
2008
2013
2014

21. Systemic toxicity
Number of blocks = 5436
• US = 2146!
• PNS = 3290!
Adverse events = 8
• Seizures = 5 (PNS)!
• Nerve injury = 3 (PNS)!
2009
Adverve event with US = 0

22. Systemic toxicity
2013

24. Improve safety
Reduce volumes
Axillary block with
1 ml per nerve !
0,7 ml to block the ulnar
nerve at the wrist

25. UltraSound-Guided Regional Anesthesia
doesn’t avoid nerve damage
Two recent case reports of persistent nerve damage with
• No pain
• No paresthesia
• at least one followed an intraneural injection

26. Nerve damage
Intraneural injection

27. Ultrasound
Contribution
The anesthetist is no longer blind
• Accuracy ~ 1 mm with high frequency probes
Visualisation of one third of all fascicles
Silvestri et al. Radiology 1995
• Fascicles size ~ 0.25 - 0.5 mm

28. Ultrasound
Contribution
Contact between nerve and needle
• motor response ≤ 0.5 mA: 74.5%
• paresthesia: 38.2%
Perlas RAPM 2006
Stimulating needle can
touch a nerve with no
motor response !

29. Bigeleisen 2006
Frequent intraneural /
subepineural injection of
local anesthetics
… under US guidance
Nerve swelling = 70%
Ultrasound
Contribution

30. Bigeleisen 2009
Ultrasound-guided supraclavicular block
and nerve stimulation
1. Needle-nerve contact
Ä minimal stimulating current
2. Needle advanced intraneurally
Ä minimal stimulating current
Ultrasound
Contribution

31. Ultrasound
Contribution
DM: Diabetis Mellitus
Stimulating thresholds
≤ 0.2 mA never observed outside the trunk
> 0.5 mA within the trunk : 10% of patients

32. Better understanding of the limits of nerve stimulation
• Intraneural injection is (very) frequent
• MIS ≥ 0.5 mA : No guarantee of being extraneural
• Contact needle-nerve without motor response = frequent
• Subepineural needle placement without motor response = frequent
• Intraneural injection without pain or paresthesia
… and without nerve damage
Ultrasound
Contribution

33. Sala-Blanch 2009
Needles through human
sciatic nerve
Intraneural injection & nerve damage
More likely: transverse the nerve between
the fascicles rather than through them

34. A- EXTRA NEURAL
Extraneural connective tissue
B- EPINEURAL
Connective tissue between fascicles
C- INTRA-FASCICULAR
Into (between) nerve fibres
I choose where I inject…
Ultrasound contribution

35. • probability of subepinerium location of needle tip
• If motor response at an intensity < 0.2 mA
• Use a test dose (1 ml) = hydrolocation
• If you see
• Swelling = STOP all further injection (subepineural)
• Nothing when you inject = iv injection or needle tip not in US beam
• If you stop the injection
• In case of swelling … unknown risk!
• When nothing appears = risk well known (intravascular)
Nerve swelling after 1 ml
Motor response < 0.2 mA
Ultrasound contribution
needle tip is
Subepineural

36. Learnig US-guidance
① Learning curve
② Rapid improvment
③ But mistakes persist …
4

37. Learnig US-guidance
Learning curve
0
2
4
6
8
10
Trial
1
Trial
2
Trial
3
Trial
4
Trial
5
Trial
6
Composite Score of
Accuracy
0
50
100
150
200
250
Trial
1
Trial
2
Trial
3
Trial
4
Trial
5
Trial
6
Speed of performance
(sec)
Performance Ime
reduced by 48%
Improvement of
Accuracy by 59%
Rapid improvment of success

38. Learnig US-guidance
Mistakes persist
Video analyses
6 anesthesia residents
Novices in USGRA
Two most common errors
• Failure to visualize needle before
advancement
• UnintenBonal probe movement

39. Failure to visualize the needle …

40. Conclusion

41. Improve efficiency with Ultrasound
Cheaper
Compared with
Nerve stimulation
Improved success rate
• Less time to perform blocks
• Reduction of volumes
• Improve patient comfort
Easy learning
• Rapid learning curve
ü See needle tip
ü Unintentional probe
movements

42. Improve safety with Ultrasound
Decrease LAST
• Monitor needle tip
• Reduce volumes
• Detect intravascular
injection early
Decrease Nerve damage
• Don’t inject intraneurally = No nerve swelling
• Association with nerve stimulation
• Monitor injection pressures
• Use blunt tip needle
• Monitor needle tip

43. Thank You