US Guidance (us + guidance)

Distribution by Scientific Domains

Selected Abstracts

A Prospective Comparison of Ultrasound-guided and Blindly Placed Radial Arterial Catheters

Stephen Shiver MD
Abstract Background Arterial cannulation for continuous blood-pressure measurement and frequent arterial-blood sampling commonly are required in critically ill patients. Objectives To compare ultrasound (US)-guided versus traditional palpation placement of arterial lines for time to placement, number of attempts, sites used, and complications. Methods This was a prospective, randomized interventional study at a Level 1 academic urban emergency department with an annual census of 78,000 patients. Patients were randomized to either palpation or US-guided groups. Inclusion criteria were any adult patient who required an arterial line according to the treating attending. Patients who had previous attempts at an arterial line during the visit, or who could not be randomized because of time constraints, were excluded. Enrollment was on a convenience basis, during hours worked by researchers over a six-month period. Patients in either group who had three failed attempts were rescued with the other technique for patient comfort. Statistical analysis included Fisher's exact, Mann-Whitney, and Student's t-tests. Results Sixty patients were enrolled, with 30 patients randomized to each group. Patients randomized to the US group had a shorter time required for arterial line placement (107 vs. 314 seconds; difference, 207 seconds; p = 0.0004), fewer placement attempts (1.2 vs. 2.2; difference, 1; p = 0.001), and fewer sites required for successful line placement (1.1 vs. 1.6; difference, 0.5; p = 0.001), as compared with the palpation group. Conclusions In this study, US guidance for arterial cannulation was successful more frequently and it took less time to establish the arterial line as compared with the palpation method. [source]

Efficacy of fine-needle aspiration biopsy in diagnosis of breast cancer: A retrospective study of 303 cases in Bahrain

F.R.C.Path, Khalid Al-Sindi M.D.
Abstract Breast cancer is a leading cause of death in many countries worldwide and breast lesions remain a common diagnostic dilemma. Fine-needle aspiration biopsy (FNAB) has been suggested as the most important, first line, minimally invasive measure in the management of patients with breast lesions. The aim of this study is to evaluate the efficacy of FNAB in patients with breast lesions by comparing the diagnostic accuracy of cytology results with that of the definitive histological examination outcome and also to investigate the added value of a single aspirator experience to the overall diagnostic precision and compared with the internationally published results. A retrospective study of 303 breast FNAB samples were carried out by a single experienced cytopathologist with complete comparison records. The prevalence of positive cytologic diagnosis for the breast cancer was determined to be 20.4%. The overall diagnostic accuracy of FNAB was 97.9%, with a specificity and sensitivity of 98.3 and 96.5%, respectively. The overall positive and negative predictive values were determined to be 93.2 and 99.2%, respectively. In addition, the sensitivity was comparable in cases that have been attempted by palpation-guided sampling compared with those aspirations that were carried out under US guidance. Results from this study confirm that FNAB biopsies performed and reported by a dedicated, single, skilled cytopathologist are highly effective in diagnosis of breast lesions and reliable in differentiating benign and malignant breast lesions with an overall high efficacy in a specialized laboratory-based FNAB clinic. Diagn. Cytopathol. 2009. © 2009 Wiley-Liss, Inc. [source]

Emergency Nurses' Utilization of Ultrasound Guidance for Placement of Peripheral Intravenous Lines in Difficult-access Patients

Larry Brannam MD
Objectives: Emergency nurses (ENs) typically place peripheral intravenous (IV) lines, but if repeated attempts fail, emergency physicians have to obtain peripheral or central access. The authors describe the patient population for which ultrasound (US)-guided peripheral IVs are used and evaluate the success rates for such lines by ENs. Methods: This was a prospective observational study of ENs in a Level I trauma center with a census of 75,000, performing US-guided IV line placement on difficult-to-stick patients (repeated blind IV placement failure or established history). ENs were trained on an inanimate model after a 45-minute lecture. Surveys were filled out after each US-guided IV attempt on a patient. ENs could decline to fill out surveys, which recorded the reason for use of US, type of patient, and success. Successful cannulation was confirmed by drawing blood and flushing fluids. Descriptive statistics were used to evaluated data. Results: A total of 321 surveys were collected in a five-month period no ENs declined to participate. There were 280 (87%) successful attempts. Twelve (29%) of the 41 failure patients required central lines, 9 (22%) received external jugular IVs, and 20 (49%) had peripheral IV access placed under US guidance by another nurse or physician. Twenty-eight percent (90) of all patients were obese, 18% (57) had sickle cell anemia, 10% (31) were renal dialysis patients, 12% (40) were IV drug abusers, and 19% (61) had unspecified chronic illness. The remainder had no reason for difficult access given. There were four arterial punctures. Conclusions: ENs had a high success rate and few complications with use of US guidance for vascular access in a variety of difficult-access patients. [source]

Is nerve stimulation needed during an ultrasound-guided lateral sagittal infraclavicular block?

Background: The objective of the study was to evaluate the influence of ultrasound (US) guidance alone vs. neurostimulation (NS) and US (NSUS) guidance techniques on block performance time and block success rate for the lateral sagittal infraclavicular block (LSIB). Methods: In a randomized and prospective manner, 110 adult patients scheduled for distal upper limb surgery were allocated to the US or the NSUS groups. In the US group, a local anesthetic (LA) was administered only with US guidance to produce a ,U'-shaped distribution around the axillary artery. In the NSUS group, LA was administered under US guidance only after electrolocation of one of the median, ulnar or radial nerve-type responses. A total of 30 ml of LA (10 ml of levobupivacaine 5 mg/ml and 20 ml of lidocaine 20 mg/ml) was administered in both groups. Sensory block was tested at 10 min intervals for 30 min. Successful block was defined as analgesia or anesthesia of all five nerves distal to the elbow. Results: Block success rate was 94.5% in both groups. Block performance time was significantly shorter in the US than the NSUS group (157 ± 50 vs. 230 ± 104 s) (P=0.000). Block onset time was similar in both groups (12.5 ± 4.8 in the US vs. 12.8 ± 5.4 min in the NSUS groups). There were two arterial punctures in the NSUS group. Conclusions: During LSIB performance US guidance alone produces block success rate identical to both US and NS guidance yet with a shorter block performance time. [source]

Ultrasound-guided core needle biopsy of breast masses: How many cores are necessary to diagnose cancer?

Clécio, nio Murta de Lucena MD
Abstract Purpose. To investigate the number of cores required to diagnose breast cancer using ultrasound (US)-guided core needle biopsy. Methods. US-guided core biopsy of 150 masses was performed in 144 patients. For each mass, 6 cores were obtained and analyzed separately. The histopathologic diagnosis was classified as benign, malignant, or normal breast tissue. Each core was analyzed separately. For diagnostic purposes, the cases were grouped as follows: group G1 comprised the first core; group G2 comprised the first and second core; group G3 comprised the first 3 cores; up to group G6, which included all 6 cores. The results were also analyzed by tumor size (,2 cm and >2 cm). Results. The sensitivity in the diagnosis of breast cancer was 90.1% in group G1 and 94.1% in the remaining groups (G2,G6). In tumors ,2 cm, the sensitivity was 88.4% for group G1 and 90.7% for the others, whereas for tumors >2 cm the sensitivity was 91.4% for group G1 and 96.6% when 2 or more cores were obtained. Conclusion. It appears that 2 cores are sufficient to diagnose breast cancer in this study population assuming no technical error occurred in US guidance of the needle through the mass. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007 [source]

Are peripheral and neuraxial blocks with ultrasound guidance more effective and safe in children?

Summary Background and aims:, The efficacy and safety of ultrasound guided (USG) pediatric peripheral nerve and neuraxial blocks in children have not been evaluated. In this review, we have looked at the success rate, efficacy and complications with USG peripheral nerve blocks and compared with nerve stimulation or anatomical landmark based techniques in children. Methods:, All suitable studies in MEDLINE, EMBASE Drugs and Cochrane Evidence Based Medicine Reviews: Cochrane Database of Systemic Reviews databases were identified. In addition, citation review and hand search of recent pediatric anesthesia and surgical journals were done. All three authors read all selected articles independently and a consensus was achieved. All randomized controlled trials (RCTs) comparing USG peripheral and neuraxial blocks with other techniques in children were included. Results:, Ultrasound guidance has been demonstrated to improve block characteristics in children including shorter block performance time, higher success rates, shorter onset time, longer block duration, less volume of local anesthetic agents and visibility of neuraxial structures. Conclusion:, Clinical studies in children suggest that US guidance has some advantages over more traditional nerve stimulation,based techniques for regional block. However, the advantage of US guidance on safety over traditional has not been adequately demonstrated in children except ilio-inguinal blocks. [source]

A randomized, double-blind, controlled study of ultrasound-guided corticosteroid injection into the joint of patients with inflammatory arthritis,

Joanna Cunnington
Objective Most corticosteroid injections into the joint are guided by the clinical examination (CE), but up to 70% are inaccurately placed, which may contribute to an inadequate response. The aim of this study was to investigate whether ultrasound (US) guidance improves the accuracy and clinical outcome of joint injections as compared with CE guidance in patients with inflammatory arthritis. Methods A total of 184 patients with inflammatory arthritis and an inflamed joint (shoulder, elbow, wrist, knee, or ankle) were randomized to receive either US-guided or CE-guided corticosteroid injections. Visual analog scales (VAS) for assessment of function, pain, and stiffness of the target joint, a modified Health Assessment Questionnaire, and the EuroQol 5-domain questionnaire were obtained at baseline and at 2 weeks and 6 weeks postinjection. The erythrocyte sedimentation rate and C-reactive protein level were measured at baseline and 2 weeks. Contrast injected with the steroid was used to assess the accuracy of the joint injection. Results One-third of CE-guided injections were inaccurate. US-guided injections performed by a trainee rheumatologist were more accurate than the CE-guided injections performed by more senior rheumatologists (83% versus 66%; P = 0.010). There was no significant difference in clinical outcome between the group receiving US-guided injections and the group receiving CE-guided injections. Accurate injections led to greater improvement in joint function, as determined by VAS scores, at 6 weeks, as compared with inaccurate injections (30.6 mm versus 21.2 mm; P = 0.030). Clinicians who used US guidance reliably assessed the accuracy of joint injection (P < 0.001), whereas those who used CE guidance did not (P = 0.29). Conclusion US guidance significantly improves the accuracy of joint injection, allowing a trainee to rapidly achieve higher accuracy than more experienced rheumatologists. US guidance did not improve the short-term outcome of joint injection. [source]

Training for renal ablative technique using an agarose-based renal tumour-mimic model

OBJECTIVE To assess whether a recently developed porcine tumour-mimic model can serve as a training model for radiofrequency ablation (RFA) of renal masses, as the increased diagnosis of small occult renal masses has led to the development of nephron-sparing treatments, including RFA, and the techniques required for effective tumour ablation can be difficult to master. MATERIALS AND METHODS Tumour mimics were created by injecting 0.7 mL of an agarose mixture into the parenchyma of a porcine kidney, producing 1-cm spherical lesions which were hyperechoic on ultrasonography (US). The ex vivo experiment included creating 40 tumour mimics followed by RFA using US-guided needle placement. The ablation diameter was set to 15 mm to produce a margin of grossly ablated tissue around the mimic lesions. The in vivo portion involved creating 20 tumour mimics and ablating them under direct laparoscopic vision with US-guided probe placement. In each case, the mimic lesion size by US and gross examination, ablation diameter, and completion (accuracy) of ablations were recorded. RESULTS Accurate placing of the RFA needle by US guidance was difficult to learn, as all tumour-mimic lesions were either endophytic or completely intraparenchymal. The ex vivo model required ,,15 ablations before the needle was placed consistently into the lesions. The in vivo model was equally difficult to learn, with five positive margins by gross examination in the first 10 ablations, while the subsequent 10 had no positive margins. CONCLUSION The agarose-based tumour mimic is a useful target model for learning and improving US-guided ablative techniques in both the ex vivo and in vivo settings. The tumour-mimic allows the surgeon to assess targeting accuracy in an animal model. Further studies are needed to determine this model's utility as a clinical training aid. [source]