Effect of needle type on plane block spread in a cadaveric porcine model

IntroductionPlane blocks are an increasingly common type of regional anaesthesia technique in the perioperative period. Increased spread of local anaesthesia during plane blocks is thought to be related to an increased area of pain coverage. This study sought to assess differences in injectate spread comparing Tuohy needles with standard insulated stimulating block needles.Methods10 Yorkshire-Cross porcine cadavers were used in this study. Immediately following euthanasia, the cadavers underwent bilateral ultrasound-guided transversus abdominis plane (TAP) block injection with radiopaque contrast dye, with one side placed with a 20 g Tuohy needle, and the other side with a 20 g insulated stimulating block needle. Injectate spread was assessed using plain film X-ray and area of spread was measured to compare differences.ResultsAll 10 animals underwent successful ultrasound-guided TAP block placement. In all 10 animals, the area of contrast spread was greater with the Tuohy than stimulating needle. Wilcoxon signed-rank test was used to analyse the difference between the groups. The average difference between the two sides was 33.02% (p=0.002).ConclusionsThis is the first study to demonstrate differences in injectate spread with different needle types. This suggests enhanced spread with Tuohy needle compared with standard block needle, and may encourage its use during plane blocks.

Incidence of dural sac puncture during neuraxial anesthesia in cats: an observational, retrospective study

Objectives The aim of this study was to determine the occurrence of dural puncture, indicated by cerebrospinal fluid (CSF) outflow, in cats receiving neuraxial anesthesia through a lumbosacral injection guided by a pop sensation method. Methods This was an observational, retrospective study. Cats that were scheduled for lumbosacral neuraxial anesthesia were included. Medical records were analyzed to investigate: (1) demographic data; (2) neuraxial anesthesia performed (epidural/spinal); (3) type of needle used, including gauge and length; (4) presence of CSF (yes/no) and/or blood (yes/no) in the hub of the needle; and (5) flicking of the tail during needle advancement (yes/no). Results A total of 94 medical records were analyzed. A 22 G 50 mm Tuohy needle was used in all cats scheduled for an epidural injection (n = 60), whereas a 22 G 40 mm Quincke needle was used in all cats scheduled for an intrathecal injection (n = 34). CSF outflow was detected in 55/60 (91.7%) cats in which a Tuohy needle was used, and 34/34 (100%) of the cats in which a Quincke needle was used ( P = 0.15). Flicking of the tail was detected in 41/60 (68.3%) and in 24/34 (70.6%) injections with Tuohy and Quincke needles, respectively ( P >0.99). Traces of blood, but not active blood outflow, were detected via staining of the first drops of CSF in 2/34 cats in which Quincke needles were used and in none of the cats in which Tuohy needles were used ( P = 0.12). Conclusions and relevance This study shows that the lumbosacral approach for neuraxial anesthesia in cats may result in a dural sac puncture when 22 G Quincke or Tuohy needles are used. The pop sensation method should be deemed effective in predicting intrathecal but not epidural needle placement.

Comparison of Touhy and Quincke needles on intravascular injection rate in lumbar transforaminal epidural block: a randomized prospective trial

BackgroundTransforaminal epidural steroid injection is widely used in clinical practice to effectively deliver injectate into the ventral epidural space. Complications associated with intravascular injection such as spinal cord infarction and paraplegia can occur during transforaminal epidural steroid injection. To improve the safety of the procedure, avoidance of intravascular injection is crucial, for which appropriate needle selection is important. The primary aim of this study was to compare intravascular injection rates during transforaminal epidural steroid injection between commonly used Quincke and Tuohy needles.MethodTwo hundred and four transforaminal epidural steroid injection cases were randomly assigned to one of two needle groups (22-gage Quincke needle or 22-gage Tuohy needle). Intravascular injection was evaluated using digital subtraction angiography. Spread of contrast medium to the ventral and medial epidural spaces was evaluated. Procedure time was compared between the two needle types.ResultsThe overall incidence of intravascular injection was 7.8%. The rate of intravascular injection was significantly lower in the Tuohy needle group than the Quincke needle group (2.9% vs 12.7%, p=0.009). The ventral and medial epidural spread rates of the Tuohy needle group were 92.2% and 95.1%, respectively, significantly higher than those of the Quincke needle group. The procedure time was shorter in the Tuohy needle group than in the Quincke needle group (97.4 (19.3) seconds vs 117.8 (31.9) s; mean difference −20.40 (95% CI −34.35 to −6.45), p=0.005).ConclusionsIn conclusion, Tuohy needles had a lower intravascular injection rate and higher medial and ventral epidural spreading rates than Quincke needles.Trial registration numberKCT0002095.

Incidental unintentional breakage of epidural catheter in supralaminar area: A case report

Background: Among some of the known complications, breakage of epidural catheter, though is extremely rare, is a well-established entity. Visualization of retained catheter is difficult even with current radiological imaging techniques, and active surgical intervention might be necessary for removal of catheter fragment. We report such a case of breakage of an epidural catheter during its insertion which led to surgical intervention. Case Description: A 52-year-old, an 18G radiopaque epidural catheter was inserted through an 18G Tuohy needle into the epidural space at T8-T9 interspace in left lateral position. Resistance was encountered. While the catheter was being removed with gentle traction along with Tuohy needle, it sheared off at 12 cm mark. After informing the operating surgeon and the patient, immediately an magnetic resonance imaging and computed tomography (CT) scan were done. CT scan with sagittal and coronal reconstruction was done. Epidural catheter was visualized at D9 lamina-spinous process junction who was removed by surgical intervention. Conclusion: Leaving of epidural catheter puts the anesthetist in a dilemma. To evade such an event, it is important to stick to the traditional guiding principle for epidural insertion and removal. In spite of safety measures, if event occurs, the patient should be informed about it. Surgery is reserved for symptomatic patients or asymptomatic patients to avoid future complications.

Validation of a bioabsorbable device that seals perforations after Tuohy needle dural puncture in an ovine model

BackgroundWe designed a device to close accidental dural puncture via the offending puncturing epidural needle directly after diagnosis of the puncture and before removing the needle. The aim of this study was to quantify this device’s ability to seal cerebrospinal fluid leakage.MethodsForty-six anesthetized adult sheep were studied in a single-blind randomized controlled fashion in two equal groups.An intentional dural puncture was performed with an 18-gage Tuohy needle on all the sheep between L6 and S1 levels. Contrast medium was injected through the needle. Twenty-three animals receive treatment with the sealing device. Two minutes after device placement, or dural puncture in the control group, a CT scan was performed on the animals to estimate contrast material leakage. A region of interest (ROI) was defined as the region that enclosed the subarachnoid space, epidural space, and neuroforaminal canal (the vertebral body above and half of its equivalent height in sacrum below the puncture site). In this region, the total contrast volume and the volumes in the epidural space (EPIDURAL) were measured. The primary outcome measure was the EPIDURAL/ROI ratio to ascertain the proportion of intrathecally injected fluid that passed into the epidural space in both groups. The secondary outcomes were the total amount of contrast in the ROI and the EPIDURAL.ResultsThe device was deployed successfully in all but two instances, where it suffered from manufacturing defects.Leakage was less in the study group (1.0 vs 1.4 mL, p=0.008). The median EPIDURAL/ROI ratio was likewise less in the study group (29 vs 46; p=0.013; 95% CI (−27 to –3.5)).ConclusionThis novel dural puncture-sealing device, also envisaged to be used in other comparable iatrogenic leakage scenarios to be identified in the future, was able to reduce the volume of cerebrospinal fluid that leaked into the epidural space after dural puncture. The device is possibly a valuable way of preventing fluid leakage immediately after the recognition of membrane puncture.

Epidural Needle Extension through the Ligamentum Flavum Using the Standard versus the CompuFlo®-Assisted Loss of Resistance to Saline Technique: A Simulation Study

Background. The CompuFlo® epidural system has been recently introduced and validated as an objective and sensible tool to detect the epidural space. We aimed to verify whether the high sensitivity of the instrument may help the anesthesiologist to identify the epidural space very early, limiting the extension of the Tuohy needle into the epidural space. Methods. In this prospective, simulation study, we evaluated the Tuohy needle extension through a simulated ligamentum flavum during the epidural procedure performed by 52 expert anesthesiologists by using the CompuFlo® epidural instrument or their standard loss of resistance to saline technique (LORT). Results. The mean (SD) needle extension length was 3.90 (3.71) mm in the standard technique group and 0.68 (0.46) mm in the CompuFlo® group (P<000001). The extremely reduced variability of the data in the CompuFlo® group (F test 0.01) made the results obtained with this instrument highly predictable. Conclusions. Puncturing high-resistance material that simulated the ligamentum flavum, the use of CompuFlo® has determined the arrest of the needle more precociously when compared with the traditional LORT.