Confirmation Of Needle Placement Research Articles

Ultrasound-guided arthrocentesis and intra-articular injection of the hip and shoulder joints in the dog.

To provide a video tutorial on ultrasound-guided arthrocentesis and injection of the canine hip and shoulder joints. Dogs undergoing arthrocentesis or intra-articular injection for diagnostic or therapeutic purposes. The target joint is visualized in long axis with a 70% isopropyl alcohol medium and linear array probe with a frequency range of 2 to 14 MHz and footprint of 50 mm after clipping a window and preparing the region sterilely. The needle is inserted, bevel up, in long axis with the probe angled at the appropriate trajectory to enter the joint space. The needle is advanced until the tip is visualized entering the joint. Aspiration to obtain synovial fluid can further confirm needle placement or provide diagnostic sampling prior to injection. The aspirate syringe is exchanged for that containing the therapeutic agent, and injectate can then be visualized entering and/or expanding the joint upon injection. Ultrasound-guided arthrocentesis will help identify deep appendicular joints (hip and shoulder), avoid surrounding vasculature, confirm needle placement, and target joint fluid pocketing. Needle guidance into a joint can reduce iatrogenic tissue damage from inappropriate needle placement and/or by minimizing attempts. For arthrocentesis, ultrasound guidance can maximize joint fluid volume acquisition for diagnostic purposes (cytology, culture, and fluid analysis) while also avoiding blood contamination. For joint injections, ultrasound will help ensure real-time intra-articular delivery of the injectate (regardless of attaining synovial fluid feedback) to maximize the therapeutic effect. For either purpose, iatrogenic tissue damage and procedure time are minimized.

Diagnosis of traumatic shoulder arthrotomies using saline load test with intra-articular pressure monitoring.

The purpose of this study was to investigate the amount of saline required to identify a positive traumatic shoulder arthrotomy in a cadaveric model. In addition, intra-articular pressure monitoring was conducted to confirm needle placement and evaluate peak pressure curves prior to capsular failure. We conducted a cadaveric study using thirty fresh-frozen upper extremities with maintained glenohumeral joint. A shoulder arthrotomy was made in the deltopectoral interval using a 4.4-mm trocar. The joint was loaded using an 18-gauge spinal needle inserted posteriorly and attached to a pressure monitoring system. Fluid was introduced at a uniform rate of 1cc/sec until active extravasation was visualized from the anterior arthrotomy site. Statistical analysis included assessment of distribution, ANOVA and linear regression. A positive joint challenge was obtained in all specimens (n = 30) within a maximum of 59ml of fluid (mean 28ml, STD 15.4). Average intra-articular pressure at visualization (PAV) was 166.8mmHg (min., 107; max., 268). In twelve specimens, peak pressures (PP) exceeded PAV, showing a corresponding fall in pressure prior to visualization (ΔPP-PAV = 16.5). To reach a sensitivity of 90% and 95% of arthrotomies, 50 and 58ml of fluid had to be injected. Results demonstrated 58ml of fluid was required to identify a majority of shoulder arthrotomies. Intra-articular pressure monitoring identified successful needle placement. Pressure curve analysis could identify capsular failure before fluid extravasation visualization which could enhance clinical identification and treatment of traumatic shoulder arthrotomies. Level IV Diagnostic.

Evaluation of Radiation Exposure to the Patients Undergoing Positron Emission Tomography/Computed Tomography-Guided Biopsies.

Purpose:We aimed to evaluate the radiation exposure to patients undergoing positron emission tomography/computed tomography (PET/CT)-guided biopsies.Materials and Methods:Patients undergoing PET/CT-guided biopsy were recruited prospectively from October 2019 to April 2020. PET/CT-guided biopsy from a tracer avid site was done using an automated-robotic-arm 1 h after intravenous injection of F-18-fluorodeoxyglucose (FDG) (2-5 mCi) or Ga-68-PSMA (1–4 mCi). Regional CT-images were acquired for biopsy planning and confirmation of needle placement. The internal radiation exposure due to the PET component was estimated using the value of activity injected and dose-coefficient for FDG and PSMA. The external radiation exposure due to the CT component was estimated using the value of dose length product and organ coefficients conversion factor. The total effective dose during the procedure was calculated by adding exposure due to both CT and PET components. Percentage contribution from CT and PET component to total effective dose was compared using a paired t-test.Results: A total of 101 patients (76 males) were recruited for PET/CT-guided biopsy using FDG (n = 79) and PSMA (n = 22). The mean effective-dose due to PET and CT components and total effective-dose was 2.49 ± 1.02 mSv, 2.35 ± 1.03 mSv and 4.83 ± 1.90 mSv, respectively, for FDG-guided procedures and 1.60 ± 0.57 mSv, 3.06 ± 1.36 mSv, and 4.66 ± 1.37 mSv for Ga-68-PSMA-guided procedures. The percentage contribution of PET and CT in total effective-dose was comparable in F-18-FDG and Ga-68-PSMA PET/CT-guided biopsy procedures; however, for Ga-68-PSMA PET/CT-biopsies, CT contributed a higher radiation dose than PET component.Conclusion:PET/CT-guided biopsy is a safe interventional procedure, and radiation exposure to the patients was less than routine whole-body PET/CT-imaging.

Image‐guided spinal injection for pain management

Radiculopathy and spinal pain are debilitating conditions affecting millions of people worldwide each year. While most cases can be managed conservatively with physiotherapy and nonsteroidal anti-inflammatory medications, minimally invasive corticosteroid injections are the mainstay intervention for those not responsive to conservative treatment. Historically, spinal injections were performed in the absence of imaging guidance; however, imaging modalities, in particular fluoroscopy and computer tomography (CT), have become the standard of care in performing most of these procedures. Under imaging guidance, operators can accurately confirm needle placement and safely target localised pathologies.

A reliable septum exists between the lateral cord and medial and posterior cords in the costoclavicular region: Clinical and microanatomical considerations in brachial plexus anesthetic blockade.

The ultrasound-guided proximal infraclavicular costoclavicular block (PICB) appears popular but its results are inconsistent. We sought an accurate demonstration of septae formed between the brachial plexus cords. We performed in-plane, lateral-to-medial PICBs on 120 patients and recorded images. Once the most superficial lateral cord component was entered, a 0.4-0.6 mA current was applied to confirm needle placement; 5 ml of local anesthetic (LA) solution was then injected and its spread was observed and recorded. As the needle was advanced, the presence or absence of a hyperechoic linear structure was noted before the deeper compartment was reached, specifically looking for the possible displacement of such a septum. Upon initial scanning, a septum was observed in 67 of the 120 patients (46.2%). However, there was clear displacement of a linear septum between the lateral cord compartment and the medial and posterior cord compartments that prevented spread between the compartments in 94.16% of patients. Piercing the septum evoked motor responses from the medial or posterior cord. The same anatomical regions were studied microanatomically by analyzing cross-sections obtained with the same approach angle as the ultrasound probe. Intraplexus fascial septae that bundled the medial and posterior cords into one compartment and separated them from the lateral cord were demonstrated and confirmed microanatomically. This suggests the need for two separate injections (or two separate catheter placements for continuous peripheral nerve blockade) into the superficial and deep compartments to ensure LA spread around all three cords of the brachial plexus at this level.

IoCT-guided percutaneous radiofrequency ablation for trigeminal neuralgia: how I do it.

Percutaneous trigeminal nerve rhizotomy is usually performed by free-handed puncture of the foramen ovale under radiographic control with the patient kept semiconscious. The procedure has thus been reported to be highly uncomfortable for both the patient and surgeon. To our knowledge, this is the first description of a technique that includes precise navigated, CT-guided puncture of the foramen with the patient in general anesthesia and confirmation of needle placement by intraoperative CT. Radiofrequency ablation of the trigeminal nerve was guided by intraoperative CT navigation with neuromonitoring of trigeminal nerve function. The patient was kept under general anesthesia during the procedure. CT-guided percutaneous trigeminal nerve rhizotomy is a safe and efficient treatment strategy for the management of trigeminal neuralgia without the need of the patient being in a semiconscious state.

Toward the Guidance of Transbronchial Biopsy: Identifying Pulmonary Nodules With Optical Coherence Tomography

Solitary pulmonary nodules (SPNs) frequently require transbronchial needle aspiration (TBNA) or biopsy to determine malignant potential, but have variable diagnostic yields. Confirming needle placement within SPNs during TBNA could significantly increase diagnostic yield. Optical coherence tomography (OCT) provides nondestructive, high-resolution, microstructural imaging with potential to distinguish SPN from parenchyma. We have developed needle-based OCT probes compatible with TBNA. Before OCT can play any significant role in guiding clinical TBNA, OCT interpretation criteria for differentiating SPN from lung parenchyma must be developed and validated. OCT of SPN and parenchyma was performed on 111 ex vivo resection specimens. OCT criteria for parenchyma and SPN were developed and validated in a blinded assessment. Six blinded readers (two pulmonologists, two pathologists, and two OCT experts) were trained on imaging criteria in a 15-min training session prior to interpreting the validation data set. OCT of lung parenchyma displayed evenly spaced signal-void alveolar spaces, signal-intense backreflections at tissue-air interfaces, or both. SPNs lacked both of these imaging features. Independent validation of OCT criteria by the six blinded readers demonstrated sensitivity and specificity of 95.4% and 98.2%, respectively. We have developed and validated OCT criteria for lung parenchyma and SPN with sensitivity and specificity > 95% in this ex vivo study. We anticipate that OCT could be a useful complementary imaging modality to confirm needle placement during TBNA to potentially increase diagnostic yield.

Ultrasound Guided Piriformis Injection with Confirmation of Needle Placement Through Electromyography

Dear Editor: Piriformis syndrome is a controversial topic that consists of a constellation of symptoms that may mimic spondylosis, radiculopathy, sacroiliac joint pain, and facet arthropathy [1]. One of the modalities of piriformis syndrome treatment is direct injection of medication into the piriformis muscle belly [2]. Previous authors have reported various methods in performing piriformis injections: fluoroscopically, motor stimulation, and most recently, ultrasound (US) guidance [3–5]. We describe a case presentation and, to our knowledge, the first report of combined use of US with electromyography (EMG) confirmation of muscle placement for piriformis muscle injection. A 60-year-old male presented to our clinic with lower back, left hip, and left buttock pain for 6 years. The pain was sharp in quality and radiated toward the left lateral buttock and hip. The pain was rated 6/10 at initial presentation and was aggravated by prolonged sitting, squatting, and bending over. Pain was improved with rest. On examination, the patient demonstrated mild tenderness along the left lumbar spine and paraspinal muscles, as well as tenderness to palpation in the left lateral buttock area. Straight leg raise test was positive in the left lower extremity. Motor examination revealed full …

Anaphylaxis at image-guided epidural pain block secondary to corticosteroid compound

Anaphylaxis during image-guided interventional procedures is a rare but potentially fatal event. Anaphylaxis to iodinated contrast is an established and well-recognized adverse effect. However, anaphylaxis to some of the other frequently administered medications given during interventional procedures, such as corticosteroids, is not common knowledge. During caudal epidural injection, iodinated contrast is used to confirm needle placement in the epidural space at the level of the sacral hiatus. A combination of corticosteroid, local anesthetic, and saline is subsequently injected. We describe a very rare case of anaphylaxis to a component of the steroid medication instilled in the caudal epidural space.

Rapid percutaneous tracheal catheterization using electrical guidance

To the Editor, Percutaneous needle tracheostomy or cricothyroidotomy establishes emergent airway access in situations of ‘‘cannot ventilate, cannot intubate.’’ 1 Currently, most clinicians and paramedics rely on palpation of anatomical landmarks and aspiration of air to guide needle puncture and confirm needle placement into the trachea. However, landmarking through palpation can be unreliable due to variability in patient sex, size, and body composition, and true aspiration of air from the trachea is hard to interpret in many cases. Moreover, difficulties can arise during needle insertion, including inability to cannulate the airway and perforation of the posterior or lateral aspects of the tracheal wall. Multiple attempts at needle insertion may be required, heightening these risks. Consequently, the complication rate of needle tracheostomy or cricothyroidotomy in emergency situations can be as high as 40%. Given this high complication rate and the critical and time-sensitive nature of the procedure, most physicians and paramedics would benefit from a reliable, objective, and unsophisticated method to increase its speed and accuracy. Here, we invent a novel method involving the simple presence or absence of an electrical current as a means to identify and guide needle placement into the trachea. With a grounded electrode on the body, the tip of an insulated needle maintains a closed electrical circuit when in contact with any tissue – in this case, the tracheal wall or peritracheal tissues (Fig. 1). Insertion of the tip of the insulated needle into the lumen of the air-filled trachea impedes the current, opening the electrical circuit. Based on these principles, the absence of electrical conductance could serve as a simple practical signal to detect insulated needle entrance into the trachea. Conveniently, most modern nerve stimulators have the ability to produce an audible and/or visual signal, enabling easy and rapid detection of the presence or absence of an electrical current. We demonstrated this concept in both a male and a female cadaver using a 21G 64 mm insulated needle with an 18G catheter assembly (MultiSet, Pajunk, Germany) and a commonly used nerve stimulator (HNS 12, B.Braun, Germany). Preliminary results proved encouraging, with 100% success in identifying the exact moment of needle tip entrance into the trachea (multiple insertions, more than five times for each cadaver), as viewed by bronchoscopy (Fig. 2). The cadavers were in legal custody of the Division of Anatomy of the author’s institution, and the procedures were performed with the permission from the Division of Anatomy and in compliance with the institutional ethical standards for the use of human material in medical education. As displayed in Fig. 2, real-time needle puncture of the tracheal wall was demonstrated with a corresponding change in current from an initial setting of 1.0 mA to 0.0 mA (pulse wideth 0.1 msec; 2 Hz), and it was also indicated by an instantaneous audible switch of signal tone. Importantly, this feature also serves as a warning signal, alerting the user that the needle tip is in contact with the posterior tracheal wall. The tracheal wall is also at risk of being punctured if the needle is advanced too far or is positioned too obliquely such that the needle tip touches a lateral aspect of the tracheal wall when advanced a short distance. Therefore, this technique can both confirm initial penetration of the tracheal wall and help guide positioning of the insulated needle in the airway. Once the needlecatheter assembly has been inserted successfully into the airway lumen, the needle is withdrawn. Following this step, the clinician has the option of providing temporary B. C. H. Tsui, MD (&) J. Tsui University of Alberta, Edmonton, AB, Canada e-mail: btsui@ualberta.ca

Gadolinium Encephalopathy After Intrathecal Gadolinium Injection

Gadolinium-induced encephalopathy is a well documented complication due to the inadvertent entrance of a high dose of gadolinium into the intrathecal compartment. In lab animals, injecting gadolinium into the intrathecal compartment resulted in neurotoxicity and seizures. It is also well recognized that the presence of autologous blood in the intrathecal compartment can cause a broad range of neurological changes that can include seizures and mental status changes. At the time of writing this report, there were no references in the literature of simultaneous injection of gadolinium and blood into the subarachnoid space. We present a case of a patient who received a high dose of gadolinium in the epidural space for needle placement confirmation during a fluoroscopically-guided epidural steroid injection for the treatment of lumbar radiculopathy. The injection was complicated by a wet tap necessitating an epidural blood patch for post-dural puncture headache. Shortly after the injection of the autologous blood, the patient developed grand-mal seizures and mental status changes requiring endotracheal intubation and admission to an intensive care unit. We describe the clinical course and management, as well as brain MRI findings and cerebrospinal fluid (CSF) changes. The patient made a complete recovery and was discharged. This case reinforces the need for using a low dose of gadolinium for the confirmation of needle placement in the epidural space, especially in procedures that carry the risk of inadvertent intrathecal injection. We attribute these findings to inadvertent simultaneous intrathecal injection of high dose gadolinium and autologous blood. A literature review of the cases of gadolinium-induced encephalopathy is provided followed by discussion.

Posterior Circulation Stroke after C1–C2 Intraarticular Facet Steroid Injection: Evidence for Diffuse Microvascular Injury

Posterior Circulation Stroke after C1–C2 Intraarticular Facet Steroid Injection: Evidence for Diffuse Microvascular Injury

Interventional Pain Management using Fluoroscopy and Ultrasound Imaging Techniques

Interventional Pain Management using Fluoroscopy and Ultrasound Imaging Techniques Interventional injection therapies play a major role in the management of various pain conditions and are becoming an integral part of the multidisciplinary therapies required to improve and rehabilitate pain patients. Many of these procedures have historically been performed without imaging guidance. Imaging-guided techniques with fluoroscopy or ultrasound increase the precision of these procedures and help confirm needle placement. Imaging-guided techniques should lead to better results and reduced complication rates and they are now becoming more popular. These improvements are probably due in part also to better patient selection by experienced pain physicians.

Ultrasound-Guided Trigger Point Injections in the Cervicothoracic Musculature: A New and Unreported Technique

Background: Myofascial pain is defined as pain that originates from myofascial trigger points in skeletal muscle. It is prevalent in regional musculoskeletal pain syndromes, either alone or in combination with other pain generators. The myofascial pain syndrome is one of the largest groups of under diagnosed and under treated medical problems encountered in clinical practice. Trigger points are commonly seen in patients with myofascial pain which is responsible for localized pain in the affected muscles as well as referred pain patterns. Correct needle placement in a myofascial trigger point is vital to prevent complications and improve efficacy of the trigger point injection to help reduce or relieve myofascial pain. In obese patients, these injections may not reach the target tissue. In the cervicothoracic spine, a misguided or misplaced injection can result in a pneumothorax. Here, we describe an ultrasound-guided trigger point injection technique to avoid this potential pitfall. Office based ultrasound-guided injection techniques for musculoskeletal disorders have been described in the literature with regard to tendon, bursa, cystic, and joint pathologies. For the interventionalist, utilizing ultrasound yields multiple advantages technically and practically, including observation of needle placement in real-time, ability to perform dynamic studies, the possibility of diagnosing musculoskeletal pathologies, avoidance of radiation exposure, reduced overall cost, and portability of equipment within the office setting. To our knowledge, the use of ultrasound guidance in performing trigger point injection in the cervicothoracic area, particularly in obese patients, has not been previously reported. Methods: A palpable trigger point in the cervicothoracic musculature was localized and marked by indenting the skin with the tip of a plastic needle cover. The skin was then sterile prepped. Then, using an ultrasound machine with sterile coupling gel and a sterile latex free transducer cover, the musculature in the cervicothoracic spine where the palpable trigger point was detected was visualized. Then utilizing direct live ultrasound guidance, a 25-gauge 1.5 inch needle connected to a 3 mL syringe was placed into the muscle at the exact location of the presumed trigger point. This guidance helps confirm needle placement in muscle tissue and not in an adipose tissue or any other non-musculature structure. Results: The technique is simple to be performed by a pain management specialist who has ultrasound system training. Conclusion: Ultrasound-guided trigger point injections may help confirm proper needle placement within the cervicothoracic musculature. The use of ultrasound-guided trigger point injections in the cervicothoracic musculature may also reduce the potential for a pneumothorax by an improperly placed injection. Key words: Trigger point injection, myofascial pain, ultrasound

Simultaneous Ultrasound and MRI System for Breast Biopsy: Compatibility Assessment and Demonstration in a Dual Modality Phantom

Simultaneous capturing of ultrasound (US) and magnetic resonance (MR) images allows fusion of information obtained from both modalities. We propose an MR-compatible US system where MR images are acquired in a known orientation with respect to the US imaging plane and concurrent real-time imaging can be achieved. Compatibility of the two imaging devices is a major issue in the physical setup. Tests were performed to quantify the radio frequency (RF) noise introduced in MR and US images, with the US system used in conjunction with MRI scanner of different field strengths (0.5 T and 3 T). Furthermore, simultaneous imaging was performed on a dual modality breast phantom in the 0.5 T open bore and 3 T close bore MRI systems to aid needle-guided breast biopsy. Fiducial based passive tracking and electromagnetic based active tracking were used in 3 T and 0.5 T, respectively, to establish the location and orientation of the US probe inside the magnet bore. Our results indicate that simultaneous US and MR imaging are feasible with properly-designed shielding, resulting in negligible broadband noise and minimal periodic RF noise in both modalities. US can be used for real time display of the needle trajectory, while MRI can be used to confirm needle placement.

Use of gadolinium chelate to confirm epidural needle placement in patients with an iodinated contrast reaction

When performing epidural steroid injections for the management of chronic back pain, imaging guidance and a limited epidurogram improve accuracy of needle placement and ensure appropriate delivery of the injectate into the epidural space. We describe our experience using a gadolinium chelate as an alternative contrast agent for limited epidurography in patients with a history of an iodinated contrast reaction. Thirty-eight of 2,067 (1.8%) epidural steroid injections performed in our department over a 25-month period (December 2003-January 2006) employed gadolinium. All injections were performed in the lumbar spine employing a paramedian interlaminar approach. Procedural notes and patient charts were reviewed to evaluate for immediate or delayed complications related to incorrect intrathecal or intravascular needle placement. A retrospective analysis of selected fluoroscopic spot images was performed to evaluate confidence of epidural needle placement; this analysis compared these spot images against those obtained from age- and gender-matched control patients in whom iodinated contrast was used to confirm needle placement. Real-time fluoroscopic guidance permitted confident visualization of an epidurogram at the time of procedure in all 38 cases as documented in the procedural report, and no procedure resulted in a complication due to incorrect needle placement. Retrospective review of fluoroscopic spot images revealed at least moderate confidence of epidural needle placement by both readers in 29/38 cases (76.3%). Fluoroscopic spot images obtained using gadolinium yielded significantly less confidence than images obtained in control patients whose procedures were performed using iodinated contrast (P < 0.01). However, operators were sufficiently confident in needle placement based on real-time fluoroscopic images (not available in our subsequent review) to inject anesthestic in all 38 cases, despite the immediate consequences that could result from intrathecal administration. During the same time period, there were 11/2,067 (0.5%) instances of intrathecal needle placement discovered during attempted epidurography despite the use of fluoroscopy for needle guidance and reliance on loss-of-resistance technique. Gadolinium chelate represents a safe and useful alternative contrast agent for confirmation of epidural needle placement in patients with an iodinated contrast allergy.

Cement Leakage in Percutaneous Vertebroplasty

Prospective case series. To determine the safety and feasibility of routine preinjection of gelfoam embolization during percutaneous vertebroplasty. Percutaneous vertebroplasty has been used effectively in pain relief for vertebral fractures resulting from malignancy and osteoporosis. However, cement extrusion is a common problem and can lead to complications. Gelfoam embolization of venous channels before cement injection has not been widely used as a technique to prevent leakage. Thirty-one patients who met the inclusion-exclusion criteria for the study underwent percutaneous vertebroplasty. Venography was first performed to determine the flow pattern in the vertebrae and confirm needle placement. Next, routine gelfoam embolization of venous channels was performed. This was followed by low-pressure, minimal-volume cement injection. The outcome measure of cement leakage was assessed after surgery using radiographs and CT scans. There were no complications. In the 31 patients, 61 levels of vertebroplasty were performed. Overall, there were 16 leaks out of 61 levels in 12 patients (26.2%). In osteoporotic fractures, there were 11 leaks in 49 levels, giving a leakage rate of 22.5%. There was only 1 epidural leak in this group (2%), and this was asymptomatic. Seven leakages were into the adjacent disc, 2 into the body, and 1 into the paravertebral tissues. In malignant fractures, there were 5 leakages out of 12 levels (41.7%). Of these, 2 were epidural leaks (16.7%), which were asymptomatic. Complications resulting from leakage are the most feared side effect of the procedure. This has resulted in only limited application of vertebroplasty in the United Kingdom. Routine gelfoam embolization together with careful technique has been shown to be a safe and feasible method during vertebroplasty.

Needle tip localization during pericardiocentesis with a “cardiac flush” during real time ultrasonography

Study objectives: Needle tip localization with ultrasonography during pericardiocentesis is cumbersome and operator dependent. Fluid turbulence accentuated by microbubble formation during injection is readily detected in real-time ultrasonography. Blood or serosanguinous fluid aspirated into a syringe then injected back into the pericardium results in preceptible turbulance of the pericarial fluid. Injection into the ventricle can be readily visualized as a momentary increase in echogencity, a "cardiac flush" that clears within 3 to 5 contractions. We determine the sensitivity and specificity of this finding to confirm needle placement in the ventricle during pericardiocentesis using real-time ultrasonography. Methods: Yorkshire swine (institutional animal care and utilization committee approved) were intubated, anesthetized, and maintained on inhaled isoflurane. An 18-gauge spinal needle with syringe was advanced (subxiphoid approach) into the ventricle with aspiration of blood. An ultrasonographic machine (4-MHz probe) demonstrated a 4-chamber view and pericardium. An observer blinded to tip location who was familiar with the "cardiac flush" observed only the images on the ultrasonographic monitor during injections and sham injections of blood back into the ventricle. Results: A total of 69 injections were pooled from 4 pigs. Thirty-five of 43 injections into the ventricle were correctly identified by a "cardiac flush." Twenty-four of 26 sham injections were correctly identified by the absence of a "cardiac flush" (sensitivity 81.4 [95% CI 0.67 to 0.90], specificity 92.3 [95% CI 0.75 to 0.97], positive predictive value 0.94 [95% CI 0.82 to 0.98], negative predictive value 75 [95% CI 0.57 to 0.86], positive likelihood ratio 10.5, negative likelihood ratio .020). Conclusion: A "cardiac flush" seen during injection of ventricular blood back into the ventricle during real time ultrasonography can be used to confirm inadvertent placement of the needle into the ventricle during pericardiocentesis.

Intrathecal Cefazolin-Induced Seizures Following Attempted Discography

This report describes a 39 year-old woman who underwent attempted discography and intradiscal electrothermal therapy (IDET) of the L5/S1 intervertebral disc. The procedure was abandoned after multiple unsuccessful attempts to cannulate the disc. The case was complicated by at least two lumbar dural punctures, confirmed by injection of nonionic contrast that contained 12.5 mg/mL of cefazolin, included for prophylaxis of discitis. About 45 minutes later the patient developed severe back pain. Shortly thereafter she became progressively agitated and confused, and developed intractable seizures and coma. Despite aggressive treatment the patient could not be resuscitated and expired several hours later. Convulsions were initially attributed to an adverse reaction to meperidine and promethazine, given for the back pain, however this explanation proved to be untenable. In addition, the accidental administration of an ionic contrast agent, such as Hypaque(R), was excluded. Based on a detailed review of the case and the literature, it was concluded that the patient succumbed from an unintentional dose of intrathecal cefazolin, which had been diluted in the nonionic contrast agent that was used to confirm needle placement. Available evidence indicates that cefazolin is a potent epileptogenic agent when given intrathecally. The facts of the case and the evidence supporting the conclusion are presented. It is recommended that cefazolin not be mixed with the contrast agent used to document initial needle placement during discography.

Imaging-guided injection techniques with fluoroscopy and CT for spinal pain management.

Local spinal pain and radiculopathy are common conditions that debilitate millions of Americans annually. Most cases are successfully treated conservatively with rest or physical therapy. Chiropractic manipulation or, in some cases, surgery may also be performed. Percutaneous injection has been used for spinal pain management for many years, but many of these procedures have historically been performed without imaging guidance. Recently, however, newer minimally invasive, imaging-guided percutaneous techniques have been added to the list of available treatment options for spinal pain. Imaging-guided techniques with fluoroscopy or computed tomography increase the precision of these procedures and help confirm needle placement. Cervical, thoracic, lumbosacral, and sacroiliac pain can be evaluated and treated safely and effectively with injections of local anesthetics or long-acting steroids into facet joints, sacroiliac joints, selective nerve roots, spondylolytic areas, and the epidural space. Because imaging-guided techniques appear to provide better results and reduce complication rates, they are becoming more popular despite controversy regarding their effectiveness. Controversy will continue to surround these imaging-guided techniques until large, double-blinded studies become available. In the meantime, there is an increased demand for these procedures from referring physicians, and it is important to be able to safely perform them with a minimum of patient discomfort.