Subzygomatic and infraorbital approaches for maxillary nerve blockade in cats’ cadaver

ABSTRACT: This study compared the accuracy of dye placement on the maxillary nerve by using the percutaneous subzigomatic (SBZ) and infraorbitary (IO) approaches in cats’ cadavers. A second aim was to compare the accuracy of dye placement on the maxillary nerve between different untrained anesthetists. This was a prospective, randomized, blinded study, performed in 40 heads obtained from feline cadavers. Three veterinarians (A, B and C) with no previous experience with the IO approach performed the experiments. The SBZ approach was randomly performed on one side of the head and the IO approach was performed in the contralateral side of the same head. For each approach, 0.2ml of 1% methylene blue dye was injected. Scores for length of nerve staining were as follows: 0 (failure), no staining; 1 (moderate), <6mm of nerve stained; and 2 (ideal), ≥6mm of nerve stained. Median scores (interquartile range) for the SBZ and IO approaches were 2.0 (0.3-2.0) and 1.0 (0.0-2.0), respectively. Scores for length of nerve staining were higher with the SBZ approach than the IO approach (P=0.016). Considering the scores for both the SBZ and IO approaches, there was a significant difference among the three veterinarians (P=0.002). Results of this study do not support the IO approach to perform a maxillary nerve block in cats. A greater accuracy of methylene blue dye placement was observed with the SBZ approach. A variable accuracy may exist between different veterinarians when performing a maxillary nerve block employing the SBZ and IO techniques in cats.

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Novel ultrasound-guided lateral approach for femoral nerve block in cats: a pilot study

Journal of Feline Medicine and Surgery ◽

10.1177/1098612x19845719 ◽

2019 ◽

Vol 22 (4) ◽

pp. 339-343

Author(s):

Diego Rodrigo-Mocholi ◽

Fernando Martinez-Taboada

Keyword(s):

Methylene Blue ◽

Nerve Block ◽

Femoral Nerve Block ◽

Femoral Nerve ◽

Contralateral Side ◽

Lateral Approach ◽

The Novel ◽

Ultrasound Guided ◽

Pelvic Limb ◽

Nerve Staining

Objectives The aim of this study was to describe the technique for a novel lateral approach to femoral nerve block in cat cadavers. Methods Five feline cadavers were used in our prospective cadaveric experimental study. Ultrasonography was used to identify the anatomy injection site. Both pelvic limbs were injected with a volume (0.1 ml/kg) of methylene blue in each cat. The cadavers were placed in lateral recumbency, with the limb to be blocked positioned uppermost. The transducer was held perpendicular to the most proximal area of the pelvic limb, ventral to the greater trochanter and slightly cranial to the femur. Methylene blue was injected after the localisation of the femoral nerve. Immediately after the injection, the cat was turned and the technique was repeated on the contralateral side. After performing the ‘block’ in both limbs, the area was dissected bilaterally and the success was evaluated. A positive femoral nerve staining was considered for a coverage of ⩾1 cm. Results A total of 10 ultrasound-guided femoral nerve injections were performed. Ninety percent (n = 9/10) of the nerves were successfully dyed. Conclusions and relevance The novel ultrasound-guided lateral approach may be suitable and reproducible for a successful femoral nerve blockade in cats. Further investigations about the clinical usefulness and safety of this femoral nerve block in live cats are required.

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Ultrasound-Guided Inferior Alveolar Nerve Block in the Horse: Assessment of the Extraoral Approach in Cadavers

Journal of Veterinary Dentistry ◽

10.1177/0898756419844836 ◽

2019 ◽

Vol 36 (1) ◽

pp. 46-51

Author(s):

Jessica Purefoy Johnson ◽

Robert Karl Peckham ◽

Conor Rowan ◽

Alan Wolfe ◽

John Mark O’Leary

Keyword(s):

Methylene Blue ◽

Nerve Block ◽

Inferior Alveolar Nerve ◽

Lingual Nerve ◽

Blue Dye ◽

Methylene Blue Dye ◽

Inferior Alveolar Nerve Block ◽

Success Rates ◽

Ultrasound Guided ◽

Dye Staining

Blinded techniques to desensitize the inferior alveolar nerve (IAN) include intraoral, angled, and vertical extraoral approaches with reported success rates of 100%, 73%, and 59%, respectively. It has not been determined whether an ultrasound-guided extraoral approach is feasible. Further, the fascicular nature of the inferior alveolar and lingual nerves of the horse has not been described. The objectives of this study were to describe a low-volume ultrasound-guided vertical extraoral inferior alveolar nerve block technique and to describe the fascicular nature of these nerves. An ultrasound-guided approach to the IAN was conducted with a microconvex transducer and an 18-G, 15-cm spinal needle using a solution containing iodinated-contrast and methylene blue dye. Accuracy was assessed by contrast visualized at the mandibular foramen on computed tomography (CT) and methylene blue dye staining of the nerves on gross dissection. Sections of inferior alveolar and lingual nerves were submitted for histological analysis. Assessment by CT and dissection determined success rates of 81.3% and 68.8%, respectively; 68.8% of injections had inadvertent methylene blue dye staining of the lingual nerve. Nerve histology revealed both the inferior alveolar and lingual nerves to be multifascicular in nature. Mean fascicle counts for the inferior alveolar and lingual nerves were 29 and 30.8, respectively. The technique is challenging and no more accurate than previously published blinded techniques. Any extraoral approach to the IAN is likely to also desensitize the lingual nerve.

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Cadaveric Evaluation of Injectate Distribution for Two Maxillary Nerve Block Techniques in Cats

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.619244 ◽

2021 ◽

Vol 8 ◽

Author(s):

Lily V. Davis ◽

Naomi K. Hoyer ◽

Pedro Boscan ◽

Sangeeta Rao ◽

Jennifer E. Rawlinson

Keyword(s):

Nerve Block ◽

Oral Surgery ◽

Infraorbital Nerve ◽

General Anesthetic ◽

Nerve Blocks ◽

Infraorbital Foramen ◽

Maxillary Nerve ◽

Infraorbital Canal ◽

Significant Difference ◽

Maxillary Nerve Block

Regional nerve blocks have been shown to decrease general anesthetic drug requirements and improve pain management in patients undergoing surgery. Regional nerve blocks are used routinely in patients undergoing oral surgery, such as dental extractions. There is little published information regarding the efficacy of feline maxillary and infraorbital nerve blocks. The goal of the study was to compare injectate distributions of the infraorbital foramen and percutaneous maxillary nerve block techniques in feline cadavers using a combined dye and radiopaque contrast media solution to simulate an injection. There was no significant difference in length of stained nerve between the two different techniques. It was not necessary to advance the needle into the infraorbital canal to achieve effective staining of the maxillary nerve. There was no significant difference in injectate distribution between two different injectate volumes, 0.2 and 0.4 ml, indicating that the smaller volume injected at the infraorbital foramen resulted in adequate nerve staining.

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Using of modified-bentonite as low-cost sorbent for removal of methylene blue dye from aqueous solution

Association of Arab Universities Journal of Engineering Sciences ◽

10.33261/jaaru.2020.27.2.005 ◽

2020 ◽

Vol 27 (2) ◽

pp. 45-54

Author(s):

Saraa Muwafaq Ibrahim ◽

Ziad T. Abd Ali

Keyword(s):

Aqueous Solution ◽

Methylene Blue ◽

Silanol Group ◽

Infrared Spectrometry ◽

Blue Dye ◽

Ammonium Bromide ◽

Vibration Band ◽

Order Kinetic ◽

Methylene Blue Dye ◽

Modified Bentonite

Batch experiments have been studied to remove methylene blue dye (MB) from aqueous solution using modified bentonite. The modified bentonite was synthesized by replacing exchangeable calcium cations in natural bentonite with cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The characteristics of modified bentonite were studied using different analysis such as Scanning electronic microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and surface area. Where SEM shows the natural bentonite has a porous structure, a rough and uneven appearance with scattered and different block structure sizes, while the modified bentonite surface morphology was smooth and supplemented by a limited number of holes. On other hand, (FTIR) analysis that proved NH group aliphatic and aromatic group of MB and silanol group are responsible for the sorption of contaminate. The organic matter peaks at 2848 and 2930 cm-1 in the spectra of modified bentonite which are sharper than those of the natural bentonite were assigned to the CH2 scissor vibration band and the symmetrical CH3 stretching absorption band, respectively, also the 2930 cm-1 peak is assigned to CH stretching band. The batch study was provided the maximum removal efficiency (99.99 % MB) with a sorption capacity of 129.87 mg/g at specified conditions (100 mg/L, 25℃, pH 11 and 250rpm). The sorption isotherm data fitted well with the Freundlich isotherm model. The kinetic studies were revealed that the sorption follows a pseudo-second-order kinetic model which indicates chemisorption between sorbent and sorbate molecules.

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