Palpation Technique Research Articles

Comparison of ultrasound guidance and palpation technique for femoral artery catheterization in children undergoing cardiac surgery

Comparison of ultrasound guidance and palpation technique for femoral artery catheterization in children undergoing cardiac surgery

Comparison of Point-of-Care Ultrasound Guidance and the Traditional Approach in Performing Simulated Emergent Cricothyroidotomy Among Emergency Medicine Physicians, Residents, and Students.

Objective Emergency cricothyroidotomy (EC) is a rare procedure used to establish airway access when both endotracheal intubation and bag-mask ventilation have failed. Point-of-care ultrasound (POCUS) has been proposed as an adjunct to aid in identifying anatomical landmarks. However, its impact on emergency physicians when performing EC remains unclear. This study compared emergency physician and student confidence, preference, and procedure time between POCUS and traditional palpation for EC. Methods Our study utilized a randomized controlled crossover design. Emergency medicine providers attended a didactic lecture demonstrating traditional palpation and POCUS techniques for EC. The participants were randomly allocated to two simulation groups. One group started with the palpation of landmarks, while the other group started with POCUS landmark identification. A randomized crossover design was employed, and in a subsequent simulation, the reverse technique was utilized. Time to anatomic landmark identification was recorded. Participants completed a survey assessing their confidence and preference. Procedure times and confidence level differences were examined via Wilcoxon signed-rank tests. Results Sixteen participants completed the survey and were included in the final analysis. All participants successfully performed EC with the two landmark identification techniques. There was no significant difference in self-reported confidence between POCUS and palpation (p = 0.17). Landmark identification by palpation was significantly faster than POCUS (p = 0.001). A total of 10 (63%) participants preferred palpation over POCUS. Conclusions Both POCUS and traditional palpation were effective in identifying anatomical landmarks for EC. Although palpation was significantly quicker, confidence and preference between the two techniques were similar. The results suggest that both approaches can benefit clinical practice, depending on the context and provider familiarity. Further studies with larger cohorts and real-world scenarios are recommended to explore the effectiveness and safety of POCUS in EC.

Non-surgical Management of Uterine Torsion in Goat: A Report of Five Cases

Background: Uterine torsion is a relatively infrequent occurrence in goats, with reported incidence rates ranging between 1.8% to 2.0%. Accurate diagnosis of this condition poses a notable challenge due to inherent limitations associated with traditional palpation techniques, namely trans-rectal and trans-vaginal examinations. Moreover, the resemblance of clinical signs to incomplete cervical dilation compounds the diagnostic conundrum, necessitating more precise diagnostic modalities. Trans abdominal sonography has been introduced for diagnosis but is not considered completely reliable for confirming the condition. Laparohysterotomy is considered the treatment of choice. Besides, Modified Schaffer’s Method has also been used for the correction of torsion and has proven competent. Methods: Trans-vaginal examination for the diagnosis of the condition followed by correction using Modified Schaffer’s Method was attempted in every case. As per the circumstance, a mutation in necessary cases followed by forced extraction was attempted for the removal of the fetus. Result: The non-surgical detorsion approach proved effective, allowing transvaginal palpation of the fetus in the birth canal in all cases, relieving maternal discomfort from dystocia. Additionally, this method eliminated the need for laparohysterotomy, thus mitigating the risk to the goat.

Ultrasound in Skin Cancer: Why, How, and When to Use It?

Skin cancer is the most common cancer in human beings. Ultrasound is a powerful and non-invasive imaging technique that has expanded its use in dermatology, including in the skin cancer field. The full range of critical anatomical information provided by ultrasound cannot be deduced from a naked eye examination, palpation, or other imaging techniques such as dermoscopy, confocal microscopy, magnetic resonance imaging, or PET-CT (Positron Emission Tomography-Computed Tomography). This review practically analyzes the main ultrasonographic features of the most common types of skin cancers and the performance of the locoregional staging according to the literature, which is illustrated by state-of-the-art clinical and ultrasonographic correlations. The most common types of skin cancer show recognizable ultrasonographic patterns. Among the current radiological imaging techniques, ultrasound has the highest axial spatial resolution. Compared to other imaging techniques used in dermatology, it shows the great advantage of penetrating the soft tissues thoroughly, which allows us to detect and identify the most common skin types of skin cancer, including both the primary tumor and its locoregional metastases.

Evaluating iodine deficiency and goiter in hilly areas of District Poonch Azad Jammu Kashmir.

Iodine deficiency is considered as a global challenge, even after decades of efforts to solve the issue. Our objective was to assess the iodine deficiency status and associated prevalence of goiter in population groups (school-age children and women) from rural areas of District Poonch, and to assess the determinants of iodine deficiency in the area. Cross-sectional study was conducted in District Poonch Azad Jammu and Kashmir from 25 April 2022 to 30 June 2023. A total of 150 goiter patients from different villages of the District Poonch was included. Their urinary iodine concentration and goiter prevalence was assessed. Using palpation techniques, a trained and experienced public health officer assessed the presence of goiters based on WHO/ UNICEF/ICCIDD criteria. Descriptive statistics were computed for continuous variables and presented in frequency and percentage, based on the distributional characteristics of the data. chi-square was used to check association between socio-demographic factors and goiter. It was a HEC Project No.: 20-16988/NRPU/R&D/HEC/2021. Iodine status and associated goiter prevalence was high and 59.3% of them were severely iodine deficient. Within the district, the highest severe iodine deficiency was observed in 81.1% goiter patients of the Rawalakot subdivision, Hajira and Abbaspur subdivisions. Regarding goiter status 40% of the patients were classified with palpable-visible goiter and 56% were characterized with visible but nodular goiter. Study showed that there was a severe iodine deficiency and associated goiter prevalence in the area. Policymakers should take actions for future to overcome iodine deficiency in future.

Clinical Utility of Ultrasonographic Guidance for Arterial Catheterization in Patients with Obesity: A Randomized Controlled Trial

ObjectivesWe aimed to compare the success and complication rates of radial artery catheterizations between ultrasound guidance and conventional palpation technique in obese patients by anesthesia residents with similar levels of experience in both methods. Another objective was to measure the skin-to-artery distance of radial, brachial, and dorsalis pedis arteries using ultrasound with standardized anatomical landmarks. DesignProspective, randomized controlled trial SettingSingle tertiary center ParticipantsEighty adults with a body mass index (BMI) ≥ 30 kg·m-2 InterventionsUltrasound guidance or conventional palpation method Measurements and Main ResultsThe primary outcome was the first-attempt success rate of arterial catheterizations. The skin-to-artery distance of the radial artery in the BMI groups of 40–49 and ≥ 50 kg/m2 was significantly greater than that of the BMI group of 30–39 kg·m-2, mean difference: 1.0 mm [95% confidence interval (CI): 0.4 – 1.7, p=0.0029] for BMI 40–49 vs. 30–39 kg/m2 and 1.5 mm (95% CI: 0.6 – 2.4, p=0.0015) for ≥ 50 vs. 30–39 kg·m-2. Similar findings were observed for the brachial artery. BMI was inversely associated with first-attempt success rates (p=0.0145) and positively with time to successful catheterization (p=0.0271). The first-attempt success and vascular complication rates of catheterization did not significantly differ between the ultrasound guidance group (65.0%; 52.5%) and the conventional palpation group (70.0%, p=0.6331; 57.5%, p=0.6531). ConclusionOur results do not support routine uses of ultrasonography during radial arterial catheterizations for obese adults when junior practitioners performed the procedure.

High Medial Longitudinal Arch of the Foot and Latent Trigger Points in Lower Limb Muscles.

Background: The objective was to evaluate the prevalence of latent trigger points (LTrPs) in lower limb muscles in participants with a high medial longitudinal arch (MLA) of the foot compared to controls. Methods: Participants with a navicular drop test of 4-9 mm were included in the control group; the high MLA group included navicular drop test values of ≤4 mm. The presence of LTrPs was assessed by palpation techniques. The muscles evaluated were medial gastrocnemius (LTrP1), lateral gastrocnemius (LTrP2), soleus (LTrP1), peroneus longus, peroneus brevis, tibialis anterior, extensor digitorum longus, flexor digitorum longus, rectus femoris, vastus medialis (LTrP1 and LTrP2), and the vastus lateralis of the quadriceps (LTrP1 and LTrP2). Results: Thirty-seven participants with high MLA and thirty-seven controls were included in the study. Twenty-nine (78.4%) participants in the high MLA group had at least 1 LTrP, compared to twenty-three (62.2%) in the control group. No statistical difference (p < 0.05) was found in the total number of LTrPs between groups (4.46 ± 3.78 vs. 3.24 ± 3.85). There were more participants (p < 0.05) with LTrPs in the tibialis anterior, extensor digitorum longus, and vastus lateralis (LTrP1 and LTrP2) in the high MLA group than in the control group. Conclusion: Although no differences were found in the number of total LTrPs between groups, the prevalence was statistically significantly higher in the tibialis anterior, extensor digitorum longus, and vastus lateralis of the participants with high MLA of the foot.

Enhancing Botulinum Toxin Injection Precision: The Efficacy of a Single Cadaveric Ultrasound Training Intervention for Improved Anatomical Localization.

Ultrasound guidance can enhance existing landmark-based injection methods, even through a brief and single exposure during a cadaveric training course. A total of twelve participants were enrolled in this training program, comprising nine physical medicine and rehabilitation specialists, one pediatrician, and two physician assistants. For each participant, one upper-limb muscle and one lower-limb muscle were randomly chosen from the preselected muscle group. Subsequently, participants were tasked with injecting both of their chosen cadaveric muscles with 1 mL of acrylic paint using a manual needle palpation technique, relying solely on their knowledge of anatomic landmarks. Participants then underwent a personalized, one-to-one ultrasound teaching session, lasting approximately five minutes, conducted by two highly experienced instructors. Following this instructive phase, participants were tasked with a second round of injections, targeting the same two muscles in the lower and upper limbs. However, this time, the injections were performed using anatomical landmarks and ultrasound guidance. To facilitate differentiation from the initial injections, a distinct color of acrylic paint was employed. When employing the anatomical landmark-based approach, the overall success rate for injections was 67%, with 16 out of 24 targeted muscles accurately injected. With the incorporation of ultrasound guidance, the success rate was 92%, precisely targeting 22 out of the 24 muscles under examination. There was an improvement in injection accuracy achievable through the integration of ultrasound guidance, even with minimal training exposure. Our single cadaveric ultra-sound training program contributes valuable insights to the utilization of ultrasound for anatomy training to help optimize the targeting of BoNT-A.

Training and assessment of skills in neuraxial access-Protocol of a scoping review.

Access to the neuraxial space, including lumbar punctures and neuraxial anaesthesia, is an everyday procedure in clinical practice. Traditionally these procedures rely on manual palpation technique, but ultrasound is a useful tool when patients prove challenging. Presently, there is a lack of evidence-based guidelines for technical skills acquisition, both with and without ultrasound, and likewise, competency assessment approaches vary globally. Accordingly, we aim to assess the current evidence regarding learning and assessment in neuraxial access ultrasound, for future educational recommendations. This scoping review will be conducted in accordance with the Preferred Reporting Items for Systematic and Meta-Analysis (PRISMA) statement, together with the PRISMA Extension for Scoping Reviews. A systematic search strategy will be based on a PICO approach, focusing on physicians, medical students, or nurses being exposed to education, training, or assessment in procedural neuraxial access ultrasound. No comparators are obligated, but outcomes should be assessable using the Kirkpatrick four levels of training evaluation. The search will be performed in Cochrane Library, Embase, Medline, Scopus, PubMed, and CINAHL. Independently, two authors will screen the studies and conflicts will be resolved by a third author. Relevant predefined data will be extracted and analysed using a descriptive approach. The quality of the studies will be assessed using the Medical Education Research Study Quality Instrument. This scoping review will contribute by presenting gathered evidence of an overview of the different approaches to achieving education and training of technical skills in neuraxial access, and how skills are tested, which could guide research and future recommendations for skills development and assessment.

A Clinico-epidemiological Study to Evaluate the Status of Iodine Deficiency Disorder in North 24 Pargana District of West Bengal

Background: Iodine deficiency disorders (IDD) being major public health problems in India, including WestBengal needs to be continuously monitored through recommended methods and indicators.Present study is aiming to assess the total goiter rate, urinary iodine excretion, iodine content of salts at households’ level among primary school children and to find association with the socio-demographic characteristics of the study population.Method: A school-based, cross-sectional study was conducted during March 2019 to August 2019 among 540schoolchildren of class three and four. Goiter was assessed by standard palpation technique, urinary iodineexcretion (UIE) was analyzed by wet digestion method and salt samples were tested by spot iodine testing kits.The total goiter rate (TGR) was 10.56 %. About 97.22 % of the salt samples tested were adequately iodized. Though consumption of iodized salt was adequate irrespective of socio demographic characteristics; goiter prevalence was significantly different with respect to mother’s education level. Median urinary iodine excretion was found to be with in normal range. Lastly, a comparison is made between indicators of IDD over years which showed significant fall of TGR % of North 24 Pgs and a significant increase of adequately iodized salt consumption from 2004 to 2019.Conclucion: 2019 resurvey of North 24 parganas indicates that the district achieved close to the goal of NIDDCP i.e. prevalence of IDD should be below 10%. It also proved that universal salt iodinization program has increased the household’s iodine consumption above national goal of 91.2%. Goiter prevalence is found to be less in children whose mother attend the education up to 12th standard and beyond.

Effectiveness of palpation technique training and practice using a muscle-nodule-palpation simulator.

[Purpose] Extant techniques for palpating nodules, a diagnostic criterion of myofascial trigger points, lack high reliability. Therefore, this study aimed to investigate the effects of training and practice using a novel muscle-nodule-palpation simulator. [Participants and Methods] Sixteen university students (age range: 19-22 years) were randomly assigned to the training (n=8) and control (n=8) groups and used the muscle-nodule-palpation simulator to determine the position and orientation of the muscle nodule embedded in the model. During the experiment, only the participants in the training group were allowed to practice nodule detection while viewing the model through its transparent material. Subsequently, both groups underwent a performance evaluation. [Results] The training group exhibited greater improvement in performance than the control group. The means and standard errors of the improvement in the proportion of successful localization of the muscle nodule were 0.14 ± 0.06 for the control group and 0.42 ± 0.09 for the training group. [Conclusion] Training using the muscle-nodule-palpation simulator improved palpation technique for nodule localization.

Comparison between Ultrasound-Guided and Palpatory Localization of the Dorsal Joint Space of the Shoulder Joint.

Arthroscopy ranks among the frequently performed interventions in orthopedics. The aim of this study was to compare the palpation technique with the ultrasound technique for locating the dorsal glenohumeral joint space (JS) in shoulder joint punctures. Participants inexperienced in ultrasound examinations were included. Palpatory and ultrasound finding of the joint space by the participants was performed according to current recommendations and was initially demonstrated by an instructional video. The ideal point (IP) was marked under ultrasound visualization by an experienced ultrasound examinator and shoulder-elbow surgeon. Furthermore, a corridor for a safe puncture was defined. The palpatorily determined point (pdP) was marked by the participants and evaluated by means of a coordinate system. The evaluation of the sonographically determined point (sdP) was performed similarly to that of the palpatory procedure. Fifty-four participants were included in the study, and the mean length of work experience was 6.3 years. On average, participants had performed 16.5 punctures of the shoulder joint and 6.8 arthroscopies of the shoulder joint. The mean experience in performing sonographic examinations of the shoulder was 27.6 examinations. A total of 100 shoulder joints were examined (54 left, 46 right shoulders). The mean deviation from the ideal point (IP) for the palpatory approach was 17.1 mm with a maximum deviation of 59.5 mm; for the sonographic technique, the mean deviation was 10.3 mm (max. 30.2 mm). Overall, 22% of pdPs were within the defined corridor, while 42% of sdPs were within the target corridor. The average difference between palpatory and sonographic approaches was 9.0 mm in favor of the sonographic technique (max. 46.5 mm). A significantly greater deviation (p < 0.001) from the IP was observed with the palpatory approach than with the sonographic approach. Based on the results, the authors recommend ultrasound imaging of the shoulder joint as well as ultrasound-assisted punctures, especially for inexperienced users. Furthermore, training in ultrasound-assisted interventions should be implemented in future training curricula.

Palpation and fluoroscopy are valid but unreliable for the assessment of femoral tunnel position after medial patellofemoral ligament reconstruction

ObjectivesThe purpose of this study was to evaluate the validity and reliability of two techniques, palpation and fluoroscopy, for assessing medial patellofemoral ligament (MPFL) reconstruction femoral tunnel position accuracy. MethodsTwenty-one fresh frozen cadaveric knees had an MPFL femoral tunnel drilled and filled with a metal screw. Tunnels were created in a nonstandard fashion to ensure the sample included a range of tunnel positions from poor to ideal. Six experienced sport medicine and arthroscopy surgeons evaluated the placement of the femoral tunnel by palpating the screw in relation to anatomic landmarks and by fluoroscopy related to Schöttle's Point. They evaluated 1) the accuracy of femoral tunnel placement, 2) the direction of tunnel error, and 3) the clinical acceptability of the tunnel position. Validity measures included sensitivity, specificity, and correlation to clinical acceptability, which were calculated for the palpation and fluoroscopic assessments. Reliability measures included interrater reliability (ICC 2,k) for femoral tunnel accuracy and percent agreement of the raters' tunnel direction assessment. ResultsThe palpation method demonstrated a sensitivity of 0.79 and specificity of 0.84 for assessing the accuracy of femoral tunnel placement, while the fluoroscopic method showed a sensitivity of 0.83 and specificity of 0.92. Pearson correlation coefficients for clinical acceptability of tunnel position were high, with both techniques ranging from .589 to .854. Interrater reliability for the palpation and fluoroscopic techniques for assessment of tunnel accuracy were 0.31 and 0.55 (ICC 2,k), respectively. Assessment of the direction of tunnel error was good with the fluoroscopic technique slightly more accurate than palpation. ConclusionThis study demonstrated that both palpation and fluoroscopy are valid techniques for assessing femoral tunnel position after MPFL reconstruction. Despite demonstrating good validity, the accuracy of assessing tunnel position was unreliable in a group of six experienced knee surgeons. Further research into MPFL reconstruction femoral tunnel assessment techniques, including patient-specific reference standards, is warranted. Level of EvidenceLevel 2.

Effectiveness of palpation technique training and practice using a muscle-nodule-palpation simulator.

[Purpose] Extant techniques for palpating nodules, a diagnostic criterion of myofascial trigger points, lack high reliability. Therefore, this study aimed to investigate the effects of training and practice using a novel muscle-nodule-palpation simulator. [Participants and Methods] Sixteen university students (age range: 19-22 years) were randomly assigned to the training (n=8) and control (n=8) groups and used the muscle-nodule-palpation simulator to determine the position and orientation of the muscle nodule embedded in the model. During the experiment, only the participants in the training group were allowed to practice nodule detection while viewing the model through its transparent material. Subsequently, both groups underwent a performance evaluation. [Results] The training group exhibited greater improvement in performance than the control group. The means and standard errors of the improvement in the proportion of successful localization of the muscle nodule were 0.14 ± 0.06 for the control group and 0.42 ± 0.09 for the training group. [Conclusion] Training using the muscle-nodule-palpation simulator improved palpation technique for nodule localization.

Use of Preoperative Lumbosacral Spine X-rays in Developing a Predictor Score for Facilitating Neuraxial Blocks in Patients undergoing Lower Limb Arthroplasty Surgeries: A Cross-sectional Study

Introduction: Due to bony changes and narrow lumbar interspinous spaces, performing a neuraxial block becomes difficult in older patients undergoing lower limb arthroplasties. Aim: To formulate a difficulty predictor score (MUSG score) for anticipating difficult Central Neuraxial Blocks (CNB) and to compare lumbar spine radiological findings with clinical findings. Materials and Methods: A cross-sectional study was conducted on 166 patients admitted for knee or hip arthroplasties from March 2023 to March 2024 in the main operation theatre complex of a tertiary care hospital. All patients were advised to get X-rays of the lumbosacral spine in both anteroposterior and lateral views before surgery. The total difficulty predictor score was calculated from the X-rays based on the presence or absence of scoliosis, bony osteophytes, angulation of spinous processes, calcification of the ligamentum flavum, and the ratio of inner and outer visible interspinous space. The minimum score was 5 and the maximum was 12. The individual score at each interspinous level was calculated and selected the space with the minimum score for the CNB. A comparison was also made with the clinically selected best space, which was identified using the traditional palpation technique. A block was labeled difficult if there were more than two attempts for spinal and epidural block, respectively. All collected data were entered into a Microsoft Excel sheet and analysed using Microsoft Excel software. Results: The study patients had a mean age of 59.83 years. The total difficulty predictor score (MUSG Score) of the lumbar spine was 5 in 3 patients (1.8%), 6-9 in 140 patients (84.3%), and ≥10 in 23 patients (13.9%). However, the minimum score at the best interspinous space was 5 in 15 patients (9%), 6-9 in 151 patients (91%), and none had a score of 10 or more. From radiological imaging, the spaces with minimal scores were in the order of L2-L3 (76), L3-L4 (62), and L1-L2 (28); while on clinical examination, they were – L2-L3 (96), L3-L4 (43), L1-L2 (23). The difference between the two was statistically significant (p-value &lt;0.05). The time required for the block procedure was longer in patients with a score of 6-9 (13.99 minutes) than in those with a score of 5 (11.13 minutes). Haemodynamic changes from baseline were also more pronounced in patients with a score of 6-9 compared to those with a score of 5. Conclusion: CNBs in patients undergoing hip and knee arthroplasties are easier to perform with the help of the difficulty predictor score (MUSG Score). A difficulty predictor score of 5 is associated with an easier block compared to higher scores.

Ultrasound-based Accuro system versus traditional palpation technique for neuraxial anaesthesia: A systematic review and meta-analysis of randomised controlled trials.

This review evaluates the efficacy and safety of Accuro, a handheld ultrasound device, compared to the palpation technique for neuraxial anaesthesia. Accuro provides real-time imaging guidance, potentially improving accuracy and efficiency. A comprehensive search across six electronic databases identified randomised clinical trials comparing Accuro with palpation for neuraxial anaesthesia. Risk ratios or mean differences with 95% confidence intervals (CIs) were calculated using a random-effects model. Bias risk was evaluated using the Cochrane Risk of Bias tool. Five studies (n=369) met the inclusion criteria. Accuro showed a favourable risk ratio for first insertion success (1.44 [95% CI [1.01, 2.05], p=0.05]). It significantly reduced needle skin passes (MD -0.63; 95% CI [-1.05, -0.21]; p<0.01), but not needle redirection (MD -1.31; 95% CI [-2.71, 0.11]; p=0.07). Procedure time was shorter in palpation (MD 127.82; 95% CI [8.68, -246.97]; p=0.04). Four studies had a low risk of bias; one had some concerns. Accuro can potentially improve success rates and reduce skin passes in neuraxial anaesthesia. Further trials with larger samples are needed, especially in patients with anticipated difficulties.

Patient and Technical Factors Associated with Difficult Arterial Access and Ultrasound Use in the Operating Room.

Arterial catheterization enables continuous hemodynamic monitoring but has been shown to cause severe complications, especially when multiple attempts are required. The aim of this study was to explore what factors were associated with multiple attempts and ultrasound use in the operating room. We performed a retrospective analysis of patients who had arterial catheters inserted at a tertiary care children's hospital from January 2018 to March 2022, identifying clinical factors that were associated with both outcomes. A total of 3946 successful arterial catheter insertions were included. Multivariable analysis showed multiple attempts were associated with noncardiac surgery: pediatric (OR: 1.79, 95% CI: 1.30-2.51), neurologic (OR: 2.63, 95% CI: 1.89-3.57), orthopedic (OR: 3.23, 95% CI: 2.27-4.55), and non-radial artery placement (OR: 5.00, 95% CI: 3.33-7.14) (all p < 0.001). Multivariable analysis showed ultrasound use was associated with neonates (OR: 9.6, 95% CI: 4.1-22.5), infants (OR: 6.98, 95% CI: 4.67-10.42), toddlers (OR: 6.10, 95% CI: 3.8-9.8), and children (OR: 2.0, 95% CI: 1.7-2.5) compared to teenagers, with cardiac surgery being relative to other specialties-pediatric (OR: 0.48, 95% CI: 0.3-0.7), neurologic (OR: 0.27, 95% CI: 0.18-0.40), and orthopedic (OR: 0.38, 95% CI: 0.25-0.58) (all p < 0.001). In our exploratory analysis, increased odds of first-attempt arterial catheter insertion success were associated with cardiac surgery, palpation technique, and radial artery placement. Younger patient age category, ASA III and IV status, cardiac surgery, and anesthesiologist placement were associated with increased odds of ultrasound use.

Identification of the length and location of the A1 pulley combining palpation technique with palm landmarks: a cadaveric study

Through anatomical morphology, to accumulate the relevant parameters of the A1 pulley of each adult finger. A total of 100 fingers were selected, dissected layer by layer, and the A1 pulley and neurovascular of each finger were observed. Measure the length of the A1 pulley, the distance between the needle knife insertion point and the proximal edge of A1 pulley, and the nerves and blood vessels on both sides. (1) The length of A1 pulleys of each finger is 6.18 ± 0.33 mm, 6.58 ± 0.73 mm, 5.98 ± 0.67 mm, 5.36 ± 1.08 mm, 5.63 ± 1.09 mm. (2) The distances between the needle knife entry point of each finger and the volar proper nerve of the ulnar finger are 7.00 ± 1.55 mm, 8.29 ± 1.46 mm, 5.10 ± 0.25 mm, 5.30 ± 0.24 mm, 0 mm; the distances from the volar proper nerve of the radial finger are 9.08 ± 0.87 mm, 4.70 ± 1.10 mm, 7.03 ± 0.72 mm, 6.81 ± 0.22 mm, 7.81 ± 0.57 mm. (3) The distances between the needle knife entry point of each finger and the proper volar artery of the ulnar finger are 10.40 ± 0.75 mm, 8.89 ± 0.53 mm, 6.35 ± 0.44 mm, 7.26 ± 0.16 mm, 0 mm, respectively; The distances from the volar proper artery of the radial finger are 8.75 ± 1.07 mm, 6.10 ± 0.35 mm, 11.44 ± 0.41 mm, 8.19 ± 0.60 mm, 9.78 ± 0.68 mm, respectively. The landmarks of the needle entry points are located at the position corresponding to the highest point of the metacarpal heads, except the tail finger. From the needle knife entry point to distal, cut the proximal edge of the A1 pulley longitudinally along the midline until the patient can flex autonomously, and pay attention to the distance between the two sides of 3.60–11.85 mm neurovascular bundle.

Letter: Comment on the comparison between ultrasound-guided dynamic needle tip positioning and acoustic shadowing technique with palpation technique for radial arterial cannulation

Letter: Comment on the comparison between ultrasound-guided dynamic needle tip positioning and acoustic shadowing technique with palpation technique for radial arterial cannulation

Comparison of ultrasound guidance and palpation technique for femoral artery catheterization in children undergoing cardiac surgery.

The aim of this study was compare the palpation technique and ultrasound-guidance for femoral artery catheterization in pediatric patients undergoing surgery for congenital heart disease. This prospective and randomized controlled study included American Society of Anesthesiologists III-IV 40 children who underwent congenital heart surgery. The patients were divided into two groups; ultrasound-guided catheterization group and palpation-guided catheterization group. Demographic and clinical characteristics of the patients, access time, success rate, number of attempts, first-attempt success, number of trials, and failed cannulations were recorded. The diameter of the femoral artery was significantly shorter, access time and numbers of trials were significantly lower, and first-attempt success rate was significantly higher in the US group. The complication rate was significantly higher in the P group. The number of failed catheterization was higher in the P group. Total cost required for the procedure was significantly lower in the US group. We found that ultrasound-guided arterial catheterization increases the success rate and the number of successful catheterizations, while reducing the overall procedure time, incidence of complications, and cost. Therefore, we believe that the use of ultrasound guidance in arterial catheterization in pediatric cardiac surgery would be a better choice.