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Pressure Monitoring of Intraneural an Perineural Injections Into the Median, Radial, and Ulnar Nerves; Lessons From a Cadaveric Study.

Krol A, Szarko M, Vala A, De Andres J - Anesth Pain Med (2015)

Bottom Line: Intraneural needle placement produced significantly greater pressures than perineural injections did.Obtained results demonstrate significant differences between intraneural and perineural injection pressures in the median, ulnar, and radial nerves.Intraneural injection pressures show low specificity but high sensitivity suggesting that pressure monitoring might be a valuable tool in improving the safety and efficacy of peripheral nerve blockade in regional anesthesia.

View Article: PubMed Central - PubMed

Affiliation: Department of Anaesthesia and Chronic Pain Service, St Georges Hospital, London, United Kingdom.

ABSTRACT

Background: Nerve damage after regional anesthesia has been of great concern to anesthetists. Various modalities have been suggested to recognize and prevent its incidence. An understudied area is the measurement of intraneural pressure during peripheral nerve blockade. Previous investigations have produced contradicting results with only one study being conducted on human cadavers.

Objectives: The purpose of this investigation was to systematically record intraneural and perineural injection pressures on the median, ulnar, and radial nerves exclusively as a primary outcome.

Materials and methods: Ultrasonography-guided injections of 1 mL of 0.9% NaCl over ten seconds were performed on phenol glycerine embalmed cadaveric median, ulnar, and radial nerves. A total of 60 injections were performed, 30 intraneural and 30 perineural injections. The injections pressure was measured using a controlled disc stimulation device. Anatomic dissection was used to confirm needle placement.

Results: Intraneural needle placement produced significantly greater pressures than perineural injections did. The mean generated pressures in median, radial, and ulnar nerves were respectively 29.4 ± 9.3, 27.3 ± 8.5, and 17.9 ± 7.0 pound per square inch (psi) (1 psi = 51.7 mmHg) for the intraneural injections and respectively 7.2 ± 2.5, 8.3 ± 2.5, and 6.7 ± 1.8 psi for perineural injections. Additionally the intraneural injection pressures of the ulnar nerve were lower than those of the median and radial nerves.

Conclusions: Obtained results demonstrate significant differences between intraneural and perineural injection pressures in the median, ulnar, and radial nerves. Intraneural injection pressures show low specificity but high sensitivity suggesting that pressure monitoring might be a valuable tool in improving the safety and efficacy of peripheral nerve blockade in regional anesthesia. Peripheral nerves "pressure mapping" hypothetically might show difference amongst various nerves depending on anatomic location, histologic structure, and ultrasonographic appearance.

No MeSH data available.


Related in: MedlinePlus

The Controlled Disc Stimulation Device
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fig17954: The Controlled Disc Stimulation Device

Mentions: All of the cadaveric tissues were obtained and utilized in accordance with the Human Tissue Act (2004), which includes first person consent for cadaveric investigation. Cadaveric preservation involved the use of phenol and glycerol rather than formaldehyde, which allowed similar tissue mobility as in vivo conditions. A total of 60 injections were conducted using 12 cadaveric arms from six cadavers. Five cadavers were initially provided to perform bilateral radial, median, and ulnar nerve injections (30 intraneural and 30 perineural). In one cadaver, the radial nerve could not be identified on one side and in another one, an ulnar nerve injection measurement was missed due to investigator’s error. As such, an extra cadaver was used to complete the sixty injections. In total, 20 injections were conducted for each of the radial, median, and ulnar nerves (10 intraneural and 10 perineural). All injections were performed at the level of the distal arm. Radial nerve was localized at the anterior compartment of the arm after leaving spiral groove between brachialis and brachioradialis muscle and before division into deep and superficial branch. Median nerve was identified medial to brachial artery in the antecubital fossa. Ulnar nerve lies most superficially under the skin, in compare to radial and median nerve, cranially to the medial epicondyle. An M-Turbo USG system (Sonosite-Fuji Inc, Bothell, WA, USA) was used with a linear 6 to 13 MHz transducer L-38 for needle placement. After identifying a cross-sectional view of the nerves at the described level, an 80-mm, 22-G needle (Sonoplex, Pajunk, Melsungen, Germany) was inserted using an in plane technique. The perineural injection was performed within 1 mm to the epineurium as per standard peripheral nerve block to ensure free flow of solution. For intraneural injection, the needle was inserted into the clearly identifiable nerve structure as seen on USG and according to the current understanding of the concept (3). For intraneural needle placement, once the needle passed the epineurium, USG assessment could not differentiate between extrafascicular (interfascicular epineurium, perineurium) or intrafascicular needle placement (endoneurium, axons). USG images of both perineural and extraneural needle position were captured and stored. Solution spread for perineural injection and nerve swelling (change in cross-sectional area) for intraneural injection were not recorded as a video clips due to a small volume of injection (1 mL) and with the assumption that it would not add value to the investigation. After needle placement, 1 mL of 0.9% NaCl was injected over ten seconds (0.1 mL/sec) and the opening injection pressure was recorded in psi using a Controlled Disc Stimulation (CDS) device (Controlled Disc Stimulation, NeuroTherm, Middleton, MA, USA) (Figure 1).


Pressure Monitoring of Intraneural an Perineural Injections Into the Median, Radial, and Ulnar Nerves; Lessons From a Cadaveric Study.

Krol A, Szarko M, Vala A, De Andres J - Anesth Pain Med (2015)

The Controlled Disc Stimulation Device
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493739&req=5

fig17954: The Controlled Disc Stimulation Device
Mentions: All of the cadaveric tissues were obtained and utilized in accordance with the Human Tissue Act (2004), which includes first person consent for cadaveric investigation. Cadaveric preservation involved the use of phenol and glycerol rather than formaldehyde, which allowed similar tissue mobility as in vivo conditions. A total of 60 injections were conducted using 12 cadaveric arms from six cadavers. Five cadavers were initially provided to perform bilateral radial, median, and ulnar nerve injections (30 intraneural and 30 perineural). In one cadaver, the radial nerve could not be identified on one side and in another one, an ulnar nerve injection measurement was missed due to investigator’s error. As such, an extra cadaver was used to complete the sixty injections. In total, 20 injections were conducted for each of the radial, median, and ulnar nerves (10 intraneural and 10 perineural). All injections were performed at the level of the distal arm. Radial nerve was localized at the anterior compartment of the arm after leaving spiral groove between brachialis and brachioradialis muscle and before division into deep and superficial branch. Median nerve was identified medial to brachial artery in the antecubital fossa. Ulnar nerve lies most superficially under the skin, in compare to radial and median nerve, cranially to the medial epicondyle. An M-Turbo USG system (Sonosite-Fuji Inc, Bothell, WA, USA) was used with a linear 6 to 13 MHz transducer L-38 for needle placement. After identifying a cross-sectional view of the nerves at the described level, an 80-mm, 22-G needle (Sonoplex, Pajunk, Melsungen, Germany) was inserted using an in plane technique. The perineural injection was performed within 1 mm to the epineurium as per standard peripheral nerve block to ensure free flow of solution. For intraneural injection, the needle was inserted into the clearly identifiable nerve structure as seen on USG and according to the current understanding of the concept (3). For intraneural needle placement, once the needle passed the epineurium, USG assessment could not differentiate between extrafascicular (interfascicular epineurium, perineurium) or intrafascicular needle placement (endoneurium, axons). USG images of both perineural and extraneural needle position were captured and stored. Solution spread for perineural injection and nerve swelling (change in cross-sectional area) for intraneural injection were not recorded as a video clips due to a small volume of injection (1 mL) and with the assumption that it would not add value to the investigation. After needle placement, 1 mL of 0.9% NaCl was injected over ten seconds (0.1 mL/sec) and the opening injection pressure was recorded in psi using a Controlled Disc Stimulation (CDS) device (Controlled Disc Stimulation, NeuroTherm, Middleton, MA, USA) (Figure 1).

Bottom Line: Intraneural needle placement produced significantly greater pressures than perineural injections did.Obtained results demonstrate significant differences between intraneural and perineural injection pressures in the median, ulnar, and radial nerves.Intraneural injection pressures show low specificity but high sensitivity suggesting that pressure monitoring might be a valuable tool in improving the safety and efficacy of peripheral nerve blockade in regional anesthesia.

View Article: PubMed Central - PubMed

Affiliation: Department of Anaesthesia and Chronic Pain Service, St Georges Hospital, London, United Kingdom.

ABSTRACT

Background: Nerve damage after regional anesthesia has been of great concern to anesthetists. Various modalities have been suggested to recognize and prevent its incidence. An understudied area is the measurement of intraneural pressure during peripheral nerve blockade. Previous investigations have produced contradicting results with only one study being conducted on human cadavers.

Objectives: The purpose of this investigation was to systematically record intraneural and perineural injection pressures on the median, ulnar, and radial nerves exclusively as a primary outcome.

Materials and methods: Ultrasonography-guided injections of 1 mL of 0.9% NaCl over ten seconds were performed on phenol glycerine embalmed cadaveric median, ulnar, and radial nerves. A total of 60 injections were performed, 30 intraneural and 30 perineural injections. The injections pressure was measured using a controlled disc stimulation device. Anatomic dissection was used to confirm needle placement.

Results: Intraneural needle placement produced significantly greater pressures than perineural injections did. The mean generated pressures in median, radial, and ulnar nerves were respectively 29.4 ± 9.3, 27.3 ± 8.5, and 17.9 ± 7.0 pound per square inch (psi) (1 psi = 51.7 mmHg) for the intraneural injections and respectively 7.2 ± 2.5, 8.3 ± 2.5, and 6.7 ± 1.8 psi for perineural injections. Additionally the intraneural injection pressures of the ulnar nerve were lower than those of the median and radial nerves.

Conclusions: Obtained results demonstrate significant differences between intraneural and perineural injection pressures in the median, ulnar, and radial nerves. Intraneural injection pressures show low specificity but high sensitivity suggesting that pressure monitoring might be a valuable tool in improving the safety and efficacy of peripheral nerve blockade in regional anesthesia. Peripheral nerves "pressure mapping" hypothetically might show difference amongst various nerves depending on anatomic location, histologic structure, and ultrasonographic appearance.

No MeSH data available.


Related in: MedlinePlus