Preprocedural Ultrasound Imaging Research Articles

Transverse ultrasound scanning of lumbar-epidural depth and its co-relation with conventional method: A prospective observational study in obese Indian parturients

Pre-procedural ultrasound (US) imaging as a tool of determining the proper insertion site and assessing lumbar-epidural depth in obese Indian parturients. The current study’s goal was to assess the epidural depth space in obese Indian parturients by ultrasound imaging with conventional technique and also to assess whether if it decreases the failure rate and number of attempts. Twenty-five obese parturients with a BMI of more than 30 kg/m who were scheduled for elective lower segment caesarean sections under lumbar epidural anesthesia and were classified as American Society of Anaesthesiology grade I & II were included. Using a curvilinear US probe (frequency 2–5 MHz), ultrasound depth-UD (lumbar epidural) was recorded in the transverse axial plane at the L3–L4 and L4–L5 intervertebral regions. Afterwards, the needle depth (ND) was monitored using a sterile linear scale during the epidural administration process using the traditional loss of resistance (LOR) approach. Any modifications to the intervertebral spacing, needle reorientation, or the quantity of tries were recorded. The results showed that UD and ND were, respectively, 4.6140 ± 0.252 cm (range 4.20–5.30 cm) and 4.720 ± 0.271 cm (range 4.2–5.5 cm). Pearson's correlation coefficient (r) for UD and ND was 0.953 (95% confidence interval: 0.8948–0.9793, r = 0.908, P < 0.001), and the 95% limits of agreement were found to be 0.266 to 0.546 cm using Bland-Altman analysis. Of all the subjects, 92% needed only one try to put the epidural, whereas 8% needed two. The current study demonstrates a significant association of ultrasound (UD) and needle depth (ND) in obese pregnant females (BMI >30 kg/m). For lumbar epidurals, a preprocedural US scan in the transverse-axial plane provides a precise needle entry site with a high success rate.

Preprocedure ultrasound imaging combined with palpation technique in epidural labor analgesia.

BACKGROUNDFor parturients with paroxysmal uterine contraction pain, rapid analgesia is needed. We used preprocedure ultrasound imaging combined with the palpation technique in epidural analgesia for labor, and evaluated the usefulness of this technique in epidural labor analgesia.AIMTo evaluate the usefulness of preprocedure ultrasound imaging in epidural analgesia for labor.METHODSIn this prospective randomized observational study, 72 parturients were assigned to two groups (combined or palpation group). The target interspace of all parturients was first identified by the palpation technique. Then in the combined group, preprocedure ultrasound imaging was used before epidural puncture. In the palpation group, only the traditional anatomical landmarks technique (palpation technique) was performed. The primary outcome was total duration of the epidural procedure (for the ultrasound group, the duration of the preprocedure ultrasound imaging was included). The secondary outcomes were the number of skin punctures, the success rate at first needle pass, the number of needle passes, the depth from the skin to epidural space, and the complications of the procedure.RESULTSTotal duration of the epidural procedure was similar between the two groups (406.5 ± 92.15 s in the combined group and 380.03 ± 128.2 s in the palpation group; P = 0.318). A significant improvement was demonstrated for epidural puncture and catheterization in the combined group. The number of needle passes was 1.14 in the combined group and 1.72 in the palpation group (P = 0.001). The number of skin puncture sites was 1.20 in the combined group and 1.25 in the palpation group (P = 0.398). The success rate at first needle pass was 88.89% in the combined group and 66.67% in the palpation group (P = 0.045).CONCLUSIONThis study demonstrated that the total duration of epidural procedures with preprocedure ultrasound imaging combined with the palpation technique was not longer than the traditional anatomical landmarks technique, which were performed by six experienced anesthesiologists in parturients with normal weights undergoing labor analgesia.

Ultrasonography for lumbar neuraxial block.

Ultrasonography can be useful to perform a lumbar neuraxial block. It aids in understanding the anatomy of the lumbar spine before the procedure. Pre-procedural ultrasound imaging provides information about the accurate intervertebral level for puncture, optimal needle insertion point, and depth of needle advancement for a successful neuraxial block. The key ultrasonographic views for lumbar neuraxial block include the transverse midline interlaminar and parasagittal oblique views. Ultrasonography can facilitate lumbar neuraxial block in difficult cases, such as the elderly, obese patients, and patients with anatomical abnormality of the lumbar spine. This review elucidates the basics of spinal ultrasonography for lumbar neuraxial block and the current evidence regarding ultrasound-guided neuraxial block in adults.

Ultrasound increases the success rate of spinal needle placement through the epidural needle during combined spinal-epidural anaesthesia: A randomised controlled study.

Combined spinal-epidural anaesthesia (CSEA) using a needle-through-needle technique is currently widely used. However, successful epidural needle placement does not mean a successful spinal needle placement during CSEA. Whether ultrasound assistance could increase the first-pass success rate of spinal needle placement for CSEA remains unknown. The aim of this study was to investigate if ultrasound assistance could increase the first-pass success rate of spinal needle placement through the epidural needle during CSEA performed by experienced anaesthesiologists in patients undergoing caesarean section. A prospective, randomised, double-blind study. Single centre, Department of Anaesthesiology, Shengjing Hospital, China Medical University, China, from June 2019 to September 2019. A total of 185 patients (aged 24 years to 52 years, American Society of Anesthesiologists grade (ASA) II-III, 38 to 40 weeks gestation) scheduled to undergo elective caesarean section under CSEA were enrolled. The patients were randomised to either an ultrasound group (patients received a preprocedural ultrasound scan, and the puncture site was identified by ultrasound imaging) and a palpation group (patients received a sham procedural ultrasound scan, and the puncture site was identified by conventional palpation). The primary outcome measure was the first-pass success rate for spinal needle placement through the epidural needle. Secondary outcome measures were total duration of CSEA, time required for successful epidural needle and spinal needle placement, number of epidural needle redirections and complications. Preprocedural ultrasound imaging significantly increased the first-pass success rate of spinal needle placement through the epidural needle compared with conventional palpation (93.8 vs. 68.8%, P < 0.001). Preprocedural ultrasound imaging also decreased the total duration of CSEA (186.9 ± 37.1 vs. 213 ± 60.4 s, P = 0.0015) and the time required for successful spinal needle placement (78.3 ± 22.9 vs. 100.1 ± 53.7 s, P < 0.01) compared with conventional palpation. Fewer patients in the ultrasound group needed epidural needle redirections during the spinal needle placement procedure than in the palpation group (four patients vs. 20 patients, P < 0.01). For experienced anaesthesiologists, preprocedural ultrasound imaging significantly increased the first-pass success rate of spinal needle placement through the epidural needle for obstetric patients undergoing caesarean section under CSEA. chictr.org.cn, identifier: ChiCTR1900024132.

Pre-procedural ultrasound assessment as a step towards the safety of percutaneous dilatational tracheostomy: a comparative study

Background: Percutaneous dilatational tracheostomy (PDT) is an inevitable procedure indicated for mechanically ventilated critically ill patients. Ultrasound (US) assisted PDT has emerged increasing safety issues. Case series were reported to confirm the advantages of USPDT. Aim: The present study aimed to compare patients subjected to USPDT with those subjected to bronchoscope guided PDT only, regarding the easiness of technique, efficacy and safety. Materials and Methods: A prospective, randomized, comparative clinical study carried on 49 adults mechanically ventilated critically ill patients in need to maintain a secure airway through elective PDT, using Ciaglia’s Blue Rhino percutaneous dilatational tracheostomy technique. 5 patients were excluded for surgical conversion, and the remaining 44 were randomly divided into 2 groups; PDT group: patients subjected to fiber optic guided PDT, and USPDT group: patients underwent pre-procedural US imaging followed by fiber optic guided PDT. Time of the technique, procedure failure, procedure difficulty, and complications were documented, our follow up ends 24-hours after the technique. Results: Pre-procedural US guided PDT was found to be easier (P<0.05), 1 puncture was needed in the USPDT group (P<0.05) with shorter time (P<0.001). The puncture site was changed in 31.8% of the PDT group of patients but not in the USPDT group. The pre-procedural US group showed less bleeding, transient hypoxemia (P<0.05) and total number of patients with minor complications (P<0.05). Conclusion: Pre-procedural ultrasound assessment of trachea and Para-tracheal soft tissues can be considered as a reliable tool to increase safety and improve outcomes of percutaneous tracheostomy

Ultrasound-assisted intrathecal injection of nusinersen in a patient with severe vertebral deformity: a case report

BackgroundSpinal muscular atrophy (SMA) is a mostly autosomal recessive genetic disease characterized by progressive muscle weakness from anterior horn degeneration. Nusinersen has recently been approved as a disease-modifying drug for SMA that needs to be administered intrathecally. Its injection is often associated with extreme difficulty since patients with SMA have severe vertebral deformity and may be with vertebral instrumentation.Case descriptionA 21-year-old female with type 2 SMA and spinal deformity underwent a series of intrathecal injections of nusinersen. The intrathecal injections have been safely and successfully done by using computed tomography imaging and ultrasonography-assisted technique.ConclusionThis the first report in which ultrasound-assisted technique has been used for the injection of nusinersen through a lumbar puncture in patients with severe spinal deformity. Use of preprocedural ultrasound imaging is highly recommended for treatments that repeatedly require intrathecal access.

A cohort study of anatomical landmark-guided midline versus pre-procedure ultrasound-guided midline technique of spinal anesthesia in elderly patients undergoing orthopedic surgery.

Background and Aims:The primary objective of the study was to compare the number of attempts and number of passes of spinal needle insertion and secondary objective was to compare complications, bloody tap, and patient discomfort in anatomical landmark-guided versus pre-procedure USG-guided midline technique of spinal anesthesia in elderly patients posted for orthopedic surgery.Material and Methods:In this a prospective observational cohort study, 60 patients of either sex, ASA grades I–III, and aged more than 65 years were randomly allocated to 2 groups of 30 patients each. In group AG (Anatomical landmark guided), standard landmark technique was used. In group UG (Ultrasound guided), pre-procedure ultrasound guided marking for insertion point of a spinal needle was done before giving spinal anesthesia. Patients in both the groups were compared on the basis of number of attempts, number of passes, vascular injury (bloody tap), pain score, complications, and procedure time.Results:Successful dural puncture on the first needle insertion attempt was achieved more in UG group (90%) than in AG group (50%) (P < 0.05). Dural puncture was not achieved in only 3.3% patients in the UG group even after three midline attempts at spinal needle insertion. Mean of the number of passes was more in AG group (1.90) than in UG group (1.07) (P < 0.05). VAS (Visual Analogue Scale) score was 0.4 in AG group and 0.3 in UG group (P > 0.05). Group UG had shorter procedure time (2.25 min) than AG group (4.35 min).Conclusion:Preprocedure ultrasound imaging is a very useful tool to facilitate the performance of central neuraxial blockade in patients with difficult anatomical landmarks, especially in elderly patients.

Recent developments in ultrasound imaging for neuraxial blockade.

Recent research has shed further light on the place of ultrasound imaging in neuraxial blockade in routine clinical practice, its use in thoracic epidurals, and real-time ultrasound-guided techniques. Compared with the conventional technique of surface landmark palpation, preprocedural ultrasound imaging minimizes technical difficulty associated with lumbar neuraxial blockade in patients with poor-quality surface landmarks. Novice practitioners are able to learn to employ the technique effectively. Safety benefits include a reduction in postprocedural back pain associated with fewer needle passes and a lower risk of procedure-associated bleeding. The advantage of ultrasound is minimal however in patients with easily discernible surface landmarks, especially if the practitioner is highly experienced. Recent trials show that preprocedural ultrasound scanning for thoracic epidural insertion reduces needle punctures and increases early analgesic efficacy compared with the palpation technique. Real-time ultrasound-guided techniques, while feasible, remain challenging and may not offer significant benefit over preprocedural imaging in lumbar neuraxial blockade. Their role in thoracic epidural insertion requires further investigation. Ultrasound imaging of the spine is a valuable technique that, while not indicated for routine use, should be part of the skillset of any practitioner that regularly performs lumbar and thoracic neuraxial blockade.

The Skin-to-epidural distance of parturients by ultrasonography: sitting position versus left lateral position

Background: Pre-procedural lumbar ultrasound scanning is a reliable tool to estimate the skin to epidural distance (SED). We conducted an observational study to compare the SED between the sitting position and lateral position using pre-procedural ultrasound imaging of the lumbar spine in parturients. Methods: Using a 2-5 MHz curvilinear transducer, we obtained images of the lumbar interspaces from L2-3 to L5-S1 in the paramedian sagittal oblique view. The individual distance from the skin to the ligamentum flavum-dura mater unit was measured at the level of L2-3, L3-4, L4-5, and L5-S1 in the left lateral position (distance in lateral position; D-lat). Subsequently, participants were placed in the sitting position, and the distance was measured in the same manner (distance in sitting position; D-sit). Data were grouped according to body mass index (BMI; kg/m2) measurements of ≥ 25 or < 25 and analyzed. The primary outcome was the change determined by ultrasound between D-lat and D-sit at the same lumbar level according to position. Results: Thirty parturients were studied. The difference between D-lat and D-sit in the same lumbar level was not statistically significant. The mean changes between D-lat and D-sit in the same lumbar level were less than 0.18 cm. In BMI ≥ 25 group, the difference between D-lat and D-sit were greater than that of BMI < 25 group at L3-4 level (P = 0.042). Conclusions: It is important for clinicians to consider that position change is associated with greater differences in SED in obese parturients (BMI ≥ 25) compared with thin parturients (BMI < 25). For obese parturients, the sitting position may be helpful. Keywords: Epidural; Obstetric; Ultrasound

Preprocedural ultrasound examination versus manual palpation for thoracic epidural catheter insertion.

Background and Aims:Ultrasound imaging before neuraxial blocks was reported to improve the ease of insertion and minimize the traumatic trials. However, the data about the use of ultrasound in thoracic epidural block are scanty. In this study, pre-insertion ultrasound scanning was compared to traditional manual palpation technique for insertion of the thoracic epidural catheter in abdominal operations.Subjects and Methods:Forty-eight patients scheduled to midline laparotomy under combined general anesthesia with thoracic epidural analgesia were included in the study. Patients were divided into two groups with regard to technique of epidural catheter insertion; ultrasound group (done ultrasound screening to determine the needle insertion point, angle of insertion, and depth of epidural space) and manual palpation group (used the traditional manual palpation technique). Number of puncture attempts, number of puncture levels, and number of needle redirection attempts were reported. Time of catheter insertion and complications were also reported in both groups.Results:Ultrasound group showed lower number of puncture attempts (1 [1, 1.25] vs. 1.5 [1, 2.75], P = 0.008), puncture levels (1 (1, 1) vs. 1 [1, 2], P = 0.002), and needle redirection attempts (0 [0, 2.25] vs. 3.5 [2, 5], P = 0.00). Ultrasound-guided group showed shorter time for catheter insertion compared to manual palpation group (140 ± 24 s vs. 213 ± 71 s P = 0.00).Conclusion:Preprocedural ultrasound imaging increased the incidence of first pass success in thoracic epidural catheter insertion and reduced the catheter insertion time compared to manual palpation method.

English

Spinal anesthesia can be difficult especially in geriatric patients, due to age-related changes in the lumbar spine. Traditionally, surface anatomical landmarks have been used as a guide for directing the spinal needle in to the subarachnoid space, but many a time, this may be difficult as the landmarks may be difficult to palpate. Hence we wanted to test the efficacy of pre-procedural ultra-sound imaging to locate the ideal space for placement of the spinal needle. Our study included one hundred patients at or above the age of 55yrs undergoing elective surgeries under spinal anesthesia. They were divided in to 2 groups of 50 each. One group was given spinal anesthesia based on clinical parameters, while the other group based on ultrasound parameters and findings. The statistical analysis was carried out using SPSS 16 software. We observed that the number of attempts and the need to change the space or needle was much lesser in the ultrasound group. Hence we concluded that a pre-procedural ultra-sound imaging predicts difficult spinal anesthesia in older patients and can be utilized to locate the ideal space for placement of the spinal needle.

The use of ultrasound improves the accuracy of epidural needle placement in cadavers

To investigate whether epidural-prepuncture ultrasound imaging improves the accuracy and quality of epidural needle placement or not? By recruiting 15 cadavers, a total of 90 epidural needle punctures to access epidural space in study group with the help of ultrasound imaging at lumbar and thoracic spinal segments were attempted. A similar number of punctures in a control group were also performed without ultrasound imaging involving the intervertebral spaces adjacent to the ones used for ultrasound guided punctures. The accuracy of needle tip placement was ascertained with the help of computed axial tomography. Six variables: puncture depth and needle angle, procedure time, number of attempts per space, steps in needle advances, number of bony contacts and number of spaces attempted, were studied and compared among the groups. The accuracy of epidural needle placement and quality of the procedure in study group were superior to the control group. The pre-procedure ultrasound imaging enhances the accuracy and quality of epidural needle placement.

Ultrasound Imaging Facilitates Spinal Anesthesia in Adults With Difficult Surface Anatomic Landmarks

Background: Poor surface anatomic landmarks are highly predictive of technical difficulty in neuraxial blockade. The authors examined the use of ultrasound imaging to reduce this difficulty. Methods: The authors recruited 120 orthopedic patients with one of the following: body mass index more than 35 kg/m 2 and poorly palpable spinous processes; moderate to severe lumbar scoliosis; or previous lumbar spine surgery. Patients were randomized to receive spinal anesthetic by the conventional surface landmark-guided technique (group LM) or by an ultrasound-guided technique (group US). Patients in group US had a preprocedural ultrasound scan to locate and mark a suitable needle insertion point. The primary outcome was the rate of successful dural puncture on the first needle insertion attempt. Normally distributed data were summarized as mean ± SD and nonnormally distributed data were summarized as median [interquartile range]. Results: The first-attempt success rate was twice as high in group US than in group LM (65% vs. 32%; P < 0.001). There was a twofold difference between groups in the number of needle insertion attempts (group US, 1 [1―2] vs. group LM, 2 [1―4]; P < 0.001) and number of needle passes (group US, 6 [1―10] vs. group LM, 13 [5―21]; P = 0.003). More time was required to establish landmarks in group US (6.7 ± 3.1; group LM, 0.6 ± 0.5 min; P < 0.001), but this was partially offset by a shorter spinal anesthesia performance time (group US, 5.0 ± 4.9 vs. group LM, 7.3 ± 7.6 min; P = 0.038). Similar results were seen in subgroup analyses of patients with body mass index more than 35 kg/m 2 and patients with poorly palpable landmarks. Conclusion: Preprocedural ultrasound imaging facilitates the performance of spinal anesthesia in the nonobstetric patient population with difficult anatomic landmarks.

Real‐time ultrasound‐guided spinal anesthesia in patients with a challenging spinal anatomy: two case reports

Spinal anesthesia may be challenging in patients with poorly palpable surface landmarks or abnormal spinal anatomy. Pre-procedural ultrasound imaging of the lumbar spine can help by providing additional anatomical information, thus permitting a more accurate estimation of the appropriate needle insertion site and trajectory. However, actual needle insertion in the pre-puncture ultrasound-assisted technique remains a 'blind' procedure. We describe two patients with an abnormal spinal anatomy in whom ultrasound-assisted spinal anesthesia was unsuccessful. Successful dural puncture was subsequently achieved using a technique of real-time ultrasound-guided spinal anesthesia. This may be a useful option in patients in whom landmark-guided and ultrasound-assisted techniques have failed.

Ultrasonography as a Preoperative Assessment Tool: Predicting the Feasibility of Central Neuraxial Blockade

A woman with severe ankylosing spondylitis presented to the preanesthetic clinic before total hip arthroplasty. She had required general anesthesia with fiberoptic intubation after failed attempts at spinal anesthesia for previous hip surgery. Using a portable ultrasound unit, we identified an open L4-5 interlaminar space and offered the patient an ultrasound-guided spinal anesthetic. Dural puncture with a single needle pass was subsequently achieved with the aid of preprocedural ultrasound imaging. Ultrasound may be a useful preoperative assessment tool for assessing the feasibility of central neuraxial blockade when technical difficulty is anticipated.

An ultrasound-assisted approach facilitates spinal anesthesia for total joint arthroplasty

Spinal anesthesia can be challenging in patients undergoing total joint arthroplasty because of poorly palpable surface landmarks and age-related changes in the lumbar spine. We hypothesized that pre-procedural ultrasound imaging would be effective in identifying the lumbar intervertebral spaces and would provide an accurate measure of the depth to the intrathecal space. Fifty patients undergoing elective total joint arthroplasty were recruited in this prospective descriptive study. Using a curved-array 2-5 MHz transducer, the lumbar spine was imaged in two views, i.e., longitudinal parasagittal (LP) and transverse midline (TM). The intervertebral levels were identified by counting upwards from the sacrum. The locations of the interlaminar spaces were identified by visualizing the ligamentum flavum-dura mater complex and the posterior aspect of the vertebral body. The needle insertion point for a midline approach was determined from the ultrasound examination and was marked on the skin of the patient's back. The mean patient age was 67 +/- 10 yr, and 46% of the patients had a body mass index >30 kg . m(-2). Surface landmarks were difficult or impossible to palpate in 38% of the patients. The scan quality on the LP and TM views was adequate or better in 100 and 98% of the patients, respectively. Dural puncture was achieved with one needle insertion attempt and within two needle insertion attempts in 84% and 98% of the patients, respectively. The ultrasound-measured depth to the intrathecal space correlated well with the actual needle insertion depth (concordance correlation coefficient = 0.82, accuracy 0.95, precision 0.86), with a tendency to overestimate the depth by just 2.1 +/- 5.4 mm. Ultrasound imaging of the lumbar spine provides clinically useful information that can facilitate spinal anesthesia in the older orthopedic patient population.

Mechanisms and outcomes of angioplasty and atherectomy assessed by intravascular ultrasound imaging.

Catheter-based intravascular ultrasound is a relatively new imaging tool to examine endovascular structure. One major goal for the development of intravascular ultrasound imaging has been to help clarify the mechanism of interventional therapies such as balloon angioplasty and directional atherectomy. Pathologic studies have suggested that plaque distribution and composition are key features that relate to initial and long-term success of coronary interventions. However, relatively little is known by angiography about the nature of plaque in the clinical setting. Intravascular ultrasound imaging provides a high resolution, "on-line" method of tracking the effects of catheter interventions such as balloon angioplasty and atherectomy. Because of its ability to visualize tissue beneath the luminal surface, ultrasound is generating new insights into the effect of plaque composition and distribution on the response to catheter therapies. With pre-procedure ultrasound imaging, it is increasingly possible to predict the result of a particular intervention, offering the potential for developing strategies of lesion-targeted therapy based on certain plaque characteristics. This article presents the early results of the GUIDE trial as a "works in progress" view of the role of intravascular ultrasound in helping interventionalists to understand--and to optimize--angioplasty and atherectomy.