Ultrasound Improves Cricothyrotomy Success in Cadavers with Poorly Defined Neck Anatomy

2015 ◽  
Vol 123 (5) ◽  
pp. 1033-1041 ◽  
Author(s):  
Naveed Siddiqui ◽  
Cristian Arzola ◽  
Zeev Friedman ◽  
Laarni Guerina ◽  
Kong Eric You-Ten

Abstract Background Misidentification of the cricothyroid membrane in a “cannot intubate-cannot oxygenate” situation can lead to failures and serious complications. The authors hypothesized that preprocedure ultrasound-guided identification of the cricothyroid membrane would reduce complications associated with cricothyrotomy. Methods A group of 47 trainees were randomized to digital palpation (n = 23) and ultrasound (n = 24) groups. Cricothyrotomy was performed on human cadavers by using the Portex® device (Smiths Medical, USA). Anatomical landmarks of cadavers were graded as follows: grade 1—easy = visual landmarks; 2—moderate = requires light palpation of landmarks; 3—difficult = requires deep palpation of landmarks; and 4—impossible = landmarks not palpable. Primary outcome was the complication rate as measured by the severity of injuries. Secondary outcomes were correct device placement, failure to cannulate, and insertion time. Results Ultrasound guidance significantly decreased the incidence of injuries to the larynx and trachea (digital palpation: 17 of 23 = 74% vs. ultrasound: 6 of 24 = 25%; relative risk, 2.88; 95% CI, 1.39 to 5.94; P = 0.001) and increased the probability of correct insertion by 5.6 times (P = 0.043) in cadavers with difficult and impossible landmark palpation (digital palpation 8.3% vs. ultrasound 46.7%). Injuries were found in 100% of the grades 3 to 4 (difficult–impossible landmark palpation) cadavers by digital palpation compared with only 33% by ultrasound (P < 0.001). The mean (SD) insertion time was significantly longer with ultrasound than with digital palpation (196.1 s [60.6 s] vs. 110.5 s [46.9 s]; P < 0.001). Conclusion Preprocedure ultrasound guidance in cadavers with poorly defined neck anatomy significantly reduces complications and improves correct insertion of the airway device in the cricothyroid membrane.

2018 ◽  
Vol 129 (6) ◽  
pp. 1132-1139 ◽  
Author(s):  
Naveed Siddiqui ◽  
Eugene Yu ◽  
Sherif Boulis ◽  
Kong Eric You-Ten

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Success of a cricothyrotomy is dependent on accurate identification of the cricothyroid membrane. The objective of this study was to compare the accuracy of ultrasonography versus external palpation in localizing the cricothyroid membrane. Methods In total, 223 subjects with abnormal neck anatomy who were scheduled for neck computed-tomography scan at University Health Network hospitals in Toronto, Canada, were randomized into two groups: external palpation and ultrasound. The localization points of the cricothyroid membrane determined by ultrasonography or external palpation were compared to the reference midpoint (computed-tomography point) of the cricothyroid membrane by a radiologist who was blinded to group allocation. Primary outcome was the accuracy in identification of the cricothyroid membrane, which was measured by digital ruler in millimeters from the computed-tomography point to the ultrasound point or external-palpation point. Success was defined as the proportion of accurate attempts within a 5-mm distance from the computed-tomography point to the ultrasound point or external-palpation point. Results The percentage of accurate attempts was 10-fold greater in the ultrasound than external-palpation group (81% vs. 8%; 95% CI, 63.6 to 81.3%; P < 0.0001). The mean (SD) distance measured from the external-palpation to computed-tomography point was five-fold greater than the ultrasound to the computed-tomography point (16.6 ± 7.5 vs. 3.4 ± 3.3 mm; 95% CI, 11.67 to 14.70; P < 0.0001). Analysis demonstrated that the risk ratio of inaccurate localization of the cricothyroid membrane was 9.14-fold greater with the external palpation than with the ultrasound (P < 0.0001). There were no adverse events observed. Conclusions In subjects with poorly defined neck landmarks, ultrasonography is more accurate than external palpation in localizing the cricothyroid membrane.


2020 ◽  
Vol 24 (2) ◽  
pp. 168-174
Author(s):  
Khor Whuan Wyeen ◽  
Syarifah Noor Nazihah Sayed Masri ◽  
Aliza Mohammad Yusof ◽  
Azarinah Izaham ◽  
Siti Nidzwani Mohammad Mahdi ◽  
...  

Background: Evaluation of the anterior neck anatomy is essential to identify the cricothyroid membrane (CTM) before invasive surgical airway. This study aimed to compare the accuracy of cricothyroid membrane identification done by digital palpation (DP) method and laryngeal handshake palpation (LHP). 


1988 ◽  
Vol 60 (01) ◽  
pp. 039-043 ◽  
Author(s):  
L Mandelbrot ◽  
M Guillaumont ◽  
M Leclercq ◽  
J J Lefrère ◽  
D Gozin ◽  
...  

SummaryVitamin K status was evaluated using coagulation studies and/ or vitamin IQ assays in a total of 53 normal fetuses and 47 neonates. Second trimester fetal blood samples were obtained for prenatal diagnosis under ultrasound guidance. Endogenous vitamin K1 concentrations (determined by high performance liquid chromatography) were substantially lower than maternal levels. The mean maternal-fetal gradient was 14-fold at mid trimester and 18-fold at birth. Despite low vitamin K levels, descarboxy prothrombin, detected by a staphylocoagulase assay, was elevated in only a single fetus and a single neonate.After maternal oral supplementation with vitamin K1, cord vitamin K1 levels were boosted 30-fold at mid trimester and 60 fold at term, demonstrating placental transfer. However, these levels were substantially lower than corresponding supplemented maternal levels. Despite elevated vitamin K1 concentrations, supplemented fetuses and neonates showed no increase in total or coagulant prothrombin activity. These results suggest that the low prothrombin levels found during intrauterine life are not due to vitamin K deficiency.


Author(s):  
Sergey Dydykin ◽  
Friedrich Paulsen ◽  
Tatyana Khorobykh ◽  
Natalya Mishchenko ◽  
Marina Kapitonova ◽  
...  

Abstract Purpose There is no systematic description of primary anatomical landmarks that allow a surgeon to reliably and safely navigate the superior and posterior mediastinum’s fat tissue spaces near large vessels and nerves during video-assisted endothoracoscopic interventions in the prone position of a patient. Our aim was to develop an algorithm of sequential visual navigation during thoracoscopic extirpation of the esophagus and determine the most permanent topographic and anatomical landmarks allowing safe thoracoscopic dissection of the esophagus in the prone position. Methods The anatomical study of the mediastinal structural features was carried out on 30 human cadavers before and after opening the right pleural cavity. Results For thoracoscopic extirpation of the esophagus in the prone position, anatomical landmarks are defined, their variants are assessed, and an algorithm for their selection is developed, allowing their direct visualization before and after opening the mediastinal pleura. Conclusion The proposed algorithm for topographic and anatomical navigation based on the key anatomical landmarks in the posterior mediastinum provides safe performance of the video-assisted thoracoscopic extirpation of the esophagus in the prone position.


2007 ◽  
Vol 46 (03) ◽  
pp. 282-286 ◽  
Author(s):  
C. Lorenz ◽  
J. von Berg

Summary Objectives : A comprehensive model of the human heart that covers multiple surfaces, like those of the four chambers and the attached vessels, is presented. It also contains the coronary arteries and a set of 25 anatomical landmarks. The statistical model is intended to provide a priori information for automated diagnostic and interventional procedures. Methods : The end-diastolic phase of the model was adapted to fit 27 clinical multi-slice computed tomography images, thus reflecting the anatomical variability to be observed in that sample. A mean cardiac motion model was also calculated from a set of eleven multi-phase computed tomography image sets. A number of experiments were performed to determine the accuracy of model-based predictions done on unseen cardiac images. Results : Using an additional deformable surface technique, the model allows for determination of all chambers and the attached vessels on the basis of given anatomical landmarks with an average accuracy of 1.1 mm. After such an individualization of the model by surface adaptation the centerlines of the three main coronary arteries may be estimated with an average accuracy of 5.2 mm. The mean motion model was used to estimate the cardiac phase of an unknown multislice computed tomography image. Conclusion : The mean shape model of the human heart as presented here complements automated image analysis methods with the required a priori information about anatomical constraints to make them work fast and robustly.


2003 ◽  
Vol 99 (6) ◽  
pp. 1387-1390 ◽  
Author(s):  
Philipp Lirk ◽  
Christian Kolbitsch ◽  
Guenther Putz ◽  
Joshua Colvin ◽  
Hans Peter Colvin ◽  
...  

Background Cervical and high thoracic epidural anesthesia and analgesia have gained increasing importance in the treatment of painful conditions and as components of anesthetics for cardiac and breast surgery. In contrast to the hanging-drop technique, the loss-of-resistance technique is thought to rely on the penetration of the ligamentum flavum. However, the exact morphology of the ligamentum flavum at different vertebral levels remains controversial. Therefore, the aim of this study was to investigate the incidence and morphology of cervical and high thoracic ligamentum flavum mid-line gaps in embalmed cadavers. Methods Vertebral column specimens were obtained from 52 human cadavers. On each dissected level, ligamentum flavum mid-line gaps were recorded and evaluated with respect to shape and size. Results The following variations were encountered: complete fusion in the mid-line, mid-line fusion with a gap in the caudal part, mid-line gap, and mid-line gap with widened caudal end. The incidence of mid-line gaps at the following levels was: C3-C4: 66%, C4-C5: 58%, C5-C6: 74%, C6-C7: 64%, C7-T1: 51%, Th1-Th2: 21%, Th2-Th3: 11%, Th3-Th4: 4%, Th4-Th5: 2%, and Th5-Th6: 2%. The mean width of mid-line gaps was 1.0 +/- 0.3 mm. Conclusions In conclusion, the present study shows that gaps in the ligamenta flava are frequent at cervical and high thoracic levels but become rare at the T3/T4 level and below, such that one cannot always rely on the ligamentum flavum as a perceptible barrier to epidural needle placement at these levels.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Andres Hughes ◽  
Mark J Dannenbaum ◽  
Peng R Chen ◽  
Arthur L Day ◽  
Huimahn A Choi ◽  
...  

Introduction: Pipeline embolization devices (PED) have become an essential tool in the endovascular treatment of complex intracranial aneurysms. A high-density stent like device, the PED functions to redirect blood flow and facilitate the growth and remodeling of the artery. Postoperative ischemic stroke proves to be the most common neurological complication associated with treatment, ranging from about 3-6% with most occurring within 30 days. Transcranial Doppler (TCD) monitoring has been used in the past to evaluate similar procedures by measuring the occurrence of microembolic signals (MES). Due to the delivery and manipulation of the PED and its thrombotic nature, microembolic events have been postulated to form during device placement and contribute to thromboembolism. Our initial study is the first to detect and measure MES during a PED procedure. Methods: Patients undergoing endovascular PED treatment were simultaneously monitored with TCD. MES were detected, separated from artifacts, and counted for each step. Results: Embolic signals were detected in all patients and were highest during deployment. With 3 PED deployments in the paraophthalmic ICA of 2 patients, the mean MES during PED deployment was 515 +/- 46. Average emboli per second during deployment was 1.62 +/- 0.59 verses 0.30 +/- 0.12 emboli per second observed prior to microcatheter insertion and manipulation. Conclusion: A very high incidence of MES was observed during the procedure and PED deployment. The little success thus far in elucidating a possible mechanism to account for PED’s associated complications warrants more investigation. Determining the occurrence of MES might reveal insight into the relative safety of each step and on the formation of distal thromboembolisms.


2021 ◽  
pp. 1098612X2110522
Author(s):  
Alfonso Rodriguez ◽  
Roger Medina-Serra ◽  
Mark J Plested ◽  
Kata Veres-Nyeki

Objectives The aim of this study was to determine the maximal endotracheal insertion length by measuring the larynx to carina (L–C) distance by means of CT. An additional objective was to establish certain anatomical landmarks to optimise the process of endotracheal intubation (ETI). Methods Head, neck and thoracic CT images from adult cats at a single referral hospital between 2013 and 2020 were retrospectively evaluated. After standardising and identifying key markers (larynx, carina and first rib) the L–C, larynx to first rib (L–1R) and first rib to carina (1R–C) distances were measured. Results Forty-five adult cats were enrolled in the study, from which a total of nine different breeds were identified. The L–C distance was 14.3 ± 1.1 cm. This was longer in male (14.7 ± 1.1 cm) than in female cats (13.5 ± 0.7 cm). The first rib (1R) was 8.8 ± 0.7 cm from the larynx and the mean 1R–C distance was 5.4 ± 0.7 cm. The carina was found within the fifth intercostal space in 93.3% (n = 42) of the cats. Conclusions and relevance The process of ETI in adult cats may be guided by using the L–C and L–1R distance for a maximal and optimal endotracheal tube introduction, respectively. In addition, the maximal insertion length may be guided by estimating the position of the carina parallel to the fifth intercostal space.


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