1
|
Shum S, Shen DD, Isoherranen N. Predicting Maternal-Fetal Disposition of Fentanyl Following Intravenous and Epidural Administration Using Physiologically Based Pharmacokinetic Modeling. Drug Metab Dispos 2021; 49:1003-1015. [PMID: 34407992 PMCID: PMC11022861 DOI: 10.1124/dmd.121.000612] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/10/2021] [Indexed: 11/22/2022] Open
Abstract
Fentanyl is an opioid analgesic used to treat obstetrical pain in parturient women through epidural or intravenous route, and unfortunately can also be abused by pregnant women. Fentanyl is known to cross the placental barrier, but how the route of administration and time after dosing affects maternal-fetal disposition kinetics at different stages of pregnancy is not well characterized. To address this knowledge gap, we developed a maternal-fetal physiologically based pharmacokinetic (mf-PBPK) model for fentanyl to evaluate the feasibility to predict the maternal and fetal plasma concentration-time profiles of fentanyl after various dosing regimens. As fentanyl is typically given via the epidural route to control labor pain, an epidural dosing site was developed using alfentanil as a reference drug and extrapolated to fentanyl. Fetal hepatic clearance of fentanyl was predicted from CYP3A7-mediated norfentanyl formation in fetal liver microsomes (intrinsic clearance = 0.20 ± 0.05 µl/min/mg protein). The developed mf-PBPK model successfully captured fentanyl maternal and umbilical cord concentrations after epidural dosing and was used to simulate the concentrations after intravenous dosing (in a drug abuse situation). The distribution kinetics of fentanyl were found to have a considerable impact on the time course of maternal:umbilical cord concentration ratio and on interpretation of observed data. The data show that mf-PBPK modeling can be used successfully to predict maternal disposition, transplacental distribution, and fetal exposure to fentanyl. SIGNIFICANCE STATEMENT: This study establishes the modeling framework for predicting the time course of maternal and fetal exposures of fentanyl opioids from mf-PBPK modeling. The model was validated based on fentanyl exposure data collected during labor and delivery after intravenous or epidural dosing. The results show that mf-PBPK modeling is a useful predictive tool for assessing fetal exposures to fentanyl opioid therapeutic regimens and potentially can be extended to other drugs of abuse.
Collapse
MESH Headings
- Administration, Intravenous
- Adult
- Analgesia, Epidural
- Analgesics, Opioid/administration & dosage
- Analgesics, Opioid/pharmacokinetics
- Anesthesia, Epidural
- Anesthesia, Obstetrical
- Aryl Hydrocarbon Hydroxylases/metabolism
- Cytochrome P450 Family 2/metabolism
- Female
- Fentanyl/administration & dosage
- Fentanyl/pharmacokinetics
- Fetus
- Humans
- Infant, Newborn
- Injections, Epidural
- Liver/metabolism
- Maternal-Fetal Exchange
- Microsomes, Liver/metabolism
- Models, Statistical
- Predictive Value of Tests
- Pregnancy
- Tissue Distribution
- Umbilical Cord/chemistry
- Umbilical Cord/metabolism
Collapse
Affiliation(s)
- Sara Shum
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| | - Danny D Shen
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| | - Nina Isoherranen
- Department of Pharmaceutics, University of Washington, Seattle, Washington
| |
Collapse
|
2
|
McLeod GA. Novel approaches to needle tracking and visualisation. Anaesthesia 2021; 76 Suppl 1:160-170. [PMID: 33426657 DOI: 10.1111/anae.15232] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2020] [Indexed: 12/22/2022]
Abstract
The accuracy and reliability of ultrasound are still insufficient to guarantee complete and safe nerve block for all patients. Injection of local anaesthetic close to, but not touching, the nerve is key to outcomes, but the exact relationship between the needle tip and nerve epineurium is difficult to evaluate, even with ultrasound. Ultrasound has insufficient resolution, tissues are difficult to discern due to acoustic impedance and needles are more difficult to see with increased angulation. The limitations of ultrasound have shifted the focus of innovation towards bio-markers that help detect needle tip position by utilising the physical properties of tissues, (e.g. pressure, electrical, optics, acoustic and elastic). Although most are at the laboratory stage and results are as yet only available from phantom or cadaver studies, clinical trials are imminent. For example, fine optical fibres placed within the lumen of block needles can measure needle tip pressure. Electrical impedance differentiates between intraneural and perineural needle tip placement. A new tip tracker needle has a piezo element embedded at its distal end that tracks the needle tip in-plane and out-of-plane as a blue/red or green circle depending on its relative location within the beam. Micro-ultrasound at the tip of the needle is in development. Early images using 40MHz in anaesthetised pigs reveal muscle striation, distinct epineurium and 30-40 fascicles > 75 micron in diameter. The next few years will see a technological revolution in tip-tracking technology that has the potential to improve patient safety and, in doing so, change practice.
Collapse
Affiliation(s)
- G A McLeod
- Ninewells Hospital, Dundee, UK.,Institute of Academic Anaesthesia, University of Dundee, UK.,University of East Anglia, Norwich, UK
| |
Collapse
|
3
|
Schneider C, Nikitichev D, Xia W, Gurusamy K, Desjardins AE, Davidson BR. Multispectral tissue mapping: developing a concept for the optical evaluation of liver disease. J Med Imaging (Bellingham) 2020; 7:066001. [PMID: 33376759 PMCID: PMC7757517 DOI: 10.1117/1.jmi.7.6.066001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 12/01/2020] [Indexed: 11/14/2022] Open
Abstract
Purpose: Alterations in the optical absorption behavior of liver tissue secondary to pathological processes can be evaluated by multispectral analysis, which is increasingly being explored as an imaging adjunct for use in liver surgery. Current methods are either invasive or have a limited wavelength spectrum, which restricts utility. This proof of concept study describes the development of a multispectral imaging (MSI) method called multispectral tissue mapping (MTM) that addresses these issues. Approach: The imaging system consists of a tunable excitation light source and a near-infrared camera. Following the development stage, proof of concept experiments are carried out where absorption spectra from colorectal cancer liver metastasis (CRLM), hepatocellular carcinoma (HCC), and liver steatosis specimen are acquired and compared to controls. Absorption spectra are compared to histopathology examination as the current gold standard for tissue assessment. Generalized linear mixed modeling is employed to compare absorption characteristics of individual pixels and to select wavelengths for false color image processing with the aim of visually enhancing cancer tissue. Results: Analysis of individual pixels revealed distinct absorption spectra therefore suggesting that MTM is possible. A prominent absorption peak at 1210 nm was found in lipid-rich animal tissues and steatotic liver specimen. Liver cancer tissue had a heterogeneous appearance on MSI. Subsequent statistical analysis suggests that measuring changes in absorption behavior may be a feasible method to estimate the pixel-based probability of cancer being present. In CRLM, this was observed throughout 1100 to 1700 nm, whereas in HCC it was concentrated around 1140 and 1430 nm. False color image processing visibly enhances contrast between cancer and normal liver tissues. Conclusions: The system's ability to enable no-touch MSI at 1100 to 1700 nm was demonstrated. Preliminary data suggest that MTM warrants further exploration as a potential imaging tool for the detection of liver cancer during surgery.
Collapse
Affiliation(s)
- Crispin Schneider
- University College London, Division of Surgery and Interventional Science, Royal Free Campus, London, United Kingdom
| | - Daniil Nikitichev
- University College London, Wellcome/EPSRC Centre for Surgical and Interventional Sciences, London, United Kingdom.,University College London, Department of Medical Physics and Bioengineering, London, United Kingdom
| | - Wenfeng Xia
- University College London, Wellcome/EPSRC Centre for Surgical and Interventional Sciences, London, United Kingdom.,University College London, Department of Medical Physics and Bioengineering, London, United Kingdom
| | - Kurinchi Gurusamy
- University College London, Division of Surgery and Interventional Science, Royal Free Campus, London, United Kingdom.,University College London, Wellcome/EPSRC Centre for Surgical and Interventional Sciences, London, United Kingdom
| | - Adrien E Desjardins
- University College London, Wellcome/EPSRC Centre for Surgical and Interventional Sciences, London, United Kingdom.,University College London, Department of Medical Physics and Bioengineering, London, United Kingdom
| | - Brian R Davidson
- University College London, Division of Surgery and Interventional Science, Royal Free Campus, London, United Kingdom.,University College London, Wellcome/EPSRC Centre for Surgical and Interventional Sciences, London, United Kingdom
| |
Collapse
|
4
|
Xia W, West SJ, Finlay MC, Pratt R, Mathews S, Mari JM, Ourselin S, David AL, Desjardins AE. Three-Dimensional Ultrasonic Needle Tip Tracking with a Fiber-Optic Ultrasound Receiver. J Vis Exp 2018. [PMID: 30199033 PMCID: PMC6231697 DOI: 10.3791/57207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Ultrasound is frequently used for guiding minimally invasive procedures, but visualizing medical devices is often challenging with this imaging modality. When visualization is lost, the medical device can cause trauma to critical tissue structures. Here, a method to track the needle tip during ultrasound image-guided procedures is presented. This method involves the use of a fiber-optic ultrasound receiver that is affixed within the cannula of a medical needle to communicate ultrasonically with the external ultrasound probe. This custom probe comprises a central transducer element array and side element arrays. In addition to conventional two-dimensional (2D) B-mode ultrasound imaging provided by the central array, three-dimensional (3D) needle tip tracking is provided by the side arrays. For B-mode ultrasound imaging, a standard transmit-receive sequence with electronic beamforming is performed. For ultrasonic tracking, Golay-coded ultrasound transmissions from the 4 side arrays are received by the hydrophone sensor, and subsequently the received signals are decoded to identify the needle tip's spatial location with respect to the ultrasound imaging probe. As a preliminary validation of this method, insertions of the needle/hydrophone pair were performed in clinically realistic contexts. This novel ultrasound imaging/tracking method is compatible with current clinical workflow, and it provides reliable device tracking during in-plane and out-of-plane needle insertions.
Collapse
Affiliation(s)
- Wenfeng Xia
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London; Department of Medical Physics and Biomedical Engineering, University College London;
| | - Simeon J West
- Department of Anaesthesia, University College Hospital
| | - Malcolm C Finlay
- Department of Medical Physics and Biomedical Engineering, University College London; St Bartholomew's Hospital and Queen Mary University of London
| | - Rosalind Pratt
- Institute for Women's Health, University College London; Centre for Medical Imaging Computing, University College London
| | - Sunish Mathews
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London; Department of Medical Physics and Biomedical Engineering, University College London
| | | | - Sebastien Ourselin
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London; Department of Medical Physics and Biomedical Engineering, University College London; Centre for Medical Imaging Computing, University College London
| | - Anna L David
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London; Institute for Women's Health, University College London; Department of Development and Regeneration, KU Leuven (Katholieke Universiteit); NIHR University College London Hospitals Biomedical Research Centre
| | - Adrien E Desjardins
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London; Department of Medical Physics and Biomedical Engineering, University College London
| |
Collapse
|
5
|
Balthasar AJR, Bydlon TM, Ippel H, van der Voort M, Hendriks BHW, Lucassen GW, van Geffen GJ, van Kleef M, van Dijk P, Lataster A. Optical signature of nerve tissue-Exploratory ex vivo study comparing optical, histological, and molecular characteristics of different adipose and nerve tissues. Lasers Surg Med 2018; 50:948-960. [PMID: 29756651 PMCID: PMC6220981 DOI: 10.1002/lsm.22938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2018] [Indexed: 02/02/2023]
Abstract
Background During several anesthesiological procedures, needles are inserted through the skin of a patient to target nerves. In most cases, the needle traverses several tissues—skin, subcutaneous adipose tissue, muscles, nerves, and blood vessels—to reach the target nerve. A clear identification of the target nerve can improve the success of the nerve block and reduce the rate of complications. This may be accomplished with diffuse reflectance spectroscopy (DRS) which can provide a quantitative measure of the tissue composition. The goal of the current study was to further explore the morphological, biological, chemical, and optical characteristics of the tissues encountered during needle insertion to improve future DRS classification algorithms. Methods To compare characteristics of nerve tissue (sciatic nerve) and adipose tissues, the following techniques were used: histology, DRS, absorption spectrophotometry, high‐resolution magic‐angle spinning nuclear magnetic resonance (HR‐MAS NMR) spectroscopy, and solution 2D 13C‐1H heteronuclear single‐quantum coherence spectroscopy. Tissues from five human freshly frozen cadavers were examined. Results Histology clearly highlights a higher density of cellular nuclei, collagen, and cytoplasm in fascicular nerve tissue (IFAS). IFAS showed lower absorption of light around 1200 nm and 1750 nm, higher absorption around 1500 nm and 2000 nm, and a shift in the peak observed around 1000 nm. DRS measurements showed a higher water percentage and collagen concentration in IFAS and a lower fat percentage compared to all other tissues. The scattering parameter (b) was highest in IFAS. The HR‐MAS NMR data showed three extra chemical peak shifts in IFAS tissue. Conclusion Collagen, water, and cellular nuclei concentration are clearly different between nerve fascicular tissue and other adipose tissue and explain some of the differences observed in the optical absorption, DRS, and HR‐NMR spectra of these tissues. Some differences observed between fascicular nerve tissue and adipose tissues cannot yet be explained but may be helpful in improving the discriminatory capabilities of DRS in anesthesiology procedures. Lasers Surg. Med. 50:948–960, 2018. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Andrea J R Balthasar
- Department of Anesthesiology and Pain Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | | | - Hans Ippel
- Department of Biochemistry, Faculty of Health Medicine and Life Science, Maastricht University, Maastricht, The Netherlands
| | | | - Benno H W Hendriks
- Philips Research, Eindhoven, The Netherlands.,Delft University of Technology, Department of BioMechanical Engineering, Delft, The Netherlands
| | | | - Geert-Jan van Geffen
- Department of Anesthesiology, University Medical Center St. Radboud, Nijmegen, The Netherlands
| | - Maarten van Kleef
- Department of Anesthesiology and Pain Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Paul van Dijk
- Department of Anatomy and Embryology, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Arno Lataster
- Department of Anatomy and Embryology, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
| |
Collapse
|
6
|
Abstract
Ultrasound is well suited for guiding many minimally invasive procedures, but its use is often precluded by the poor visibility of medical devices. When devices are not visible, they can damage critical structures, with life-threatening complications. Here, we developed the first ultrasound probe that comprises both focused and unfocused transducer elements to provide both 2D B-mode ultrasound imaging and 3D ultrasonic needle tracking. A fibre-optic hydrophone was integrated into a needle to receive Golay-coded transmissions from the probe and these data were processed to obtain tracking images of the needle tip. The measured tracking accuracy in water was better than 0.4 mm in all dimensions. To demonstrate the clinical potential of this system, insertions were performed into the spine and the uterine cavity, in swine and pregnant ovine models in vivo. In both models, the SNR ranged from 13 to 38 at depths of 22 to 38 mm, at out-of-plane distances of 1 to 15 mm, and at insertion angles of 33 to 42 degrees relative to the probe surface normal. This novel ultrasound imaging/tracking probe has strong potential to improve procedural outcomes by providing 3D needle tip locations that are co-registered to ultrasound images, while maintaining compatibility with current clinical workflow.
Collapse
|
7
|
Teng WN, Tsou MY, Chang WK, Ting CK. Eyes on the needle: Identification and confirmation of the epidural space. Asian J Anesthesiol 2017; 55:30-34. [PMID: 28971802 DOI: 10.1016/j.aja.2017.05.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 05/23/2017] [Accepted: 05/25/2017] [Indexed: 06/07/2023]
Abstract
Epidural catheters are used to provide effective intraoperative and postoperative analgesia. Standard epidural catheterization techniques rely on palpation of surface anatomy and the experience of the anesthesiologist. Failure to correctly place an epidural catheter can lead to inadequate analgesia and serious complications, such as dural puncture headache. Exciting new devices and techniques are being developed for identification of the epidural space and confirmation of catheter entry. This article reviews and describes the recent research findings. The devices and techniques are categorized into three sections: devices that modify the loss of resistance technique; visual confirmation using the epidural needle; and confirmation of placement of the epidural catheter.
Collapse
Affiliation(s)
- Wei-Nung Teng
- Department of Anaesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Beitou District, Taipei City, 11217, Taiwan, ROC
| | - Mei-Yung Tsou
- Department of Anaesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Beitou District, Taipei City, 11217, Taiwan, ROC
| | - Wen-Kuei Chang
- Department of Anaesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Beitou District, Taipei City, 11217, Taiwan, ROC
| | - Chien-Kun Ting
- Department of Anaesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Beitou District, Taipei City, 11217, Taiwan, ROC.
| |
Collapse
|
8
|
Balthasar AJR, van Geffen GJ, van der Voort M, Lucassen GW, Roggeveen S, Bruaset IJ, Bruhn J. Spectral tissue sensing to identify intra- and extravascular needle placement - A randomized single-blind controlled trial. PLoS One 2017; 12:e0172662. [PMID: 28278194 PMCID: PMC5344374 DOI: 10.1371/journal.pone.0172662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 02/08/2017] [Indexed: 11/18/2022] Open
Abstract
Safe vascular access is a prerequisite for intravenous drug admission. Discrimination between intra- and extravascular needle position is essential for procedure safety. Spectral tissue sensing (STS), based on optical spectroscopy, can provide tissue information directly from the needle tip. The primary objective of the trial was to investigate if STS can reliably discriminate intra-vascular (venous) from non-vascular punctures. In 20 healthy volunteers, a needle with an STS stylet was inserted, and measurements were performed for two intended locations: the first was subcutaneous, while the second location was randomly selected as either subcutaneous or intravenous. The needle position was assessed using ultrasound (US) and aspiration. The operators who collected the data from the spectral device were blinded to the insertion and ultrasonographic visualization procedure and the physician was blinded to the spectral data. Following offline spectral analysis, a prediction of intravascular or subcutaneous needle placement was made and compared with the “true” needle tip position as indicated by US and aspiration. Data for 19 volunteers were included in the analysis. Six out of 8 intended vascular needle placements were defined as intravascular according to US and aspiration. The remaining two intended vascular needle placements were negative for aspiration. For the other 11 final needle locations, the needle was clearly subcutaneous according to US examination and no blood was aspirated. The Mann-Whitney U test yielded a p-value of 0.012 for the between-group comparison. The differences between extra- and intravascular were in the within-group comparison computed with the Wilcoxon signed-rank test was a p-value of 0.022. In conclusion, STS is a promising method for discriminating between intravascular and extravascular needle placement. The information provided by this method may complement current methods for detecting an intravascular needle position.
Collapse
Affiliation(s)
- Andrea J. R. Balthasar
- Department of Anesthesiology and Pain Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
- * E-mail:
| | - Geert-Jan van Geffen
- Department of Anesthesiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | | | | | - Ivar J. Bruaset
- Department of Anesthesiology, Sint Maartenskliniek, Nijmegen, The Netherlands
| | - Joergen Bruhn
- Department of Anesthesiology, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
9
|
|
10
|
Elsharkawy H, Sonny A, Chin KJ. Localization of epidural space: A review of available technologies. J Anaesthesiol Clin Pharmacol 2017; 33:16-27. [PMID: 28413269 PMCID: PMC5374826 DOI: 10.4103/0970-9185.202184] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Although epidural analgesia is widely used for pain relief, it is associated with a significant failure rate. Loss of resistance technique, tactile feedback from the needle, and surface landmarks are traditionally used to guide the epidural needle tip into the epidural space (EDS). The aim of this narrative review is to critically appraise new and emerging technologies for identification of EDS and their potential role in the future. The PubMed, Cochrane Central Register of Controlled Clinical Studies, and Web of Science databases were searched using predecided search strategies, yielding 1048 results. After careful review of abstracts and full texts, 42 articles were selected to be included. Newer techniques for localization of EDS can be broadly classified into techniques that (1) guide the needle to the EDS, (2) identify needle entry into the EDS, and (3) confirm catheter location in EDS. An ideal method should be easy to learn and perform, easily reproducible with high sensitivity and specificity, identifies inadvertent intrathecal and intravascular catheter placements with ease, feasible in perioperative setting and have a cost-benefit advantage. Though none of them in their current stages of development qualify as an ideal method, many show tremendous potential. Some techniques are useful in patients with difficult spinal anatomy and infants, and thus are complementary to traditional methods. In addition to improving the existing technology, future research should aim at proving the superiority of these techniques over traditional methods, specifically regarding successful EDS localization, better safety profile, and a favorable cost-benefit ratio.
Collapse
Affiliation(s)
- Hesham Elsharkawy
- Department of General Anesthesiology and Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Abraham Sonny
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Ki Jinn Chin
- Department of Anesthesia, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
11
|
Tsiakaka O, Terosiet M, Romain O, Histace A, Benali H, Pradat PF, Vallette F, Feher M, Feruglio S. In vivo NIRS monitoring in pig Spinal Cord tissues. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:4262-5. [PMID: 26737236 DOI: 10.1109/embc.2015.7319336] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Little is known about the processes occurring after Spinal Cord damage. Whether permanent or recoverable, those processes have not been precisely characterized because their mechanism is complex and information on the functioning of this organ are partial. This study demonstrates the feasibility of Spinal Cord activity monitoring using Near Infra-Red Spectroscopy in a pig animal model. This animal has been chosen because of its comparable size and its similarities with humans. In the first step, optical characterization of the Spinal Cord tissues was performed in different conditions using a spectrophotometer. Optical Density was evaluated between 3.5 and 6.5 in the [500; 950] nm range. Secondly, adapted light sources with custom probes were used to observe autonomic functions in the spine. Results on the measured haemodynamics at rest and under stimulation show in real time the impact of a global stimulus on a local section of the Spinal Cord. The photoplethysmogram signal of the Spinal Cord showed low AC-to-DC ratio (below to 1 %).
Collapse
|
12
|
Helen L, O'Donnell BD, Moore E. Nerve localization techniques for peripheral nerve block and possible future directions. Acta Anaesthesiol Scand 2015; 59:962-74. [PMID: 25997933 DOI: 10.1111/aas.12544] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/24/2015] [Accepted: 04/05/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Ultrasound guidance is now a standard nerve localization technique for peripheral nerve block (PNB). Ultrasonography allows simultaneous visualization of the target nerve, needle, local anesthetic injectate, and surrounding anatomical structures. Accurate deposition of local anesthetic next to the nerve is essential to the success of the nerve block procedure. Due to limitations in the visibility of both needle tip and nerve surface, the precise relationship between needle tip and target nerve is unknown at the moment of injection. Importantly, nerve injury may result both from an inappropriately placed needle tip and inappropriately placed local anesthetic. The relationship between the block needle tip and target nerve is of paramount importance to the safe conduct of peripheral nerve block. METHODS This review summarizes the evolution of nerve localization in regional anesthesia, characterizes a problem faced by clinicians in performing ultrasound-guided nerve block, and explores the potential technological solutions to this problem. RESULTS To date, technology newly applied to PNB includes real-time 3D imaging, multi-planar magnetic needle guidance, and in-line injection pressure monitoring. This review postulates that optical reflectance spectroscopy and bioimpedance may allow for accurate identification of the relationship between needle tip and target nerve, currently a high priority deficit in PNB techniques. CONCLUSIONS Until it is known how best to define the relationship between needle and nerve at the moment of injection, some common sense principles are suggested.
Collapse
Affiliation(s)
- L. Helen
- Sensing and Separation Group; Chemistry Department and Life Science Interface Group; Tyndall National Institute; University College Cork; Cork Ireland
| | - B. D. O'Donnell
- Department of Anesthesia; Cork University Hospital & ASSERT for Health Centre; University College Cork; Cork Ireland
| | - E. Moore
- Sensing and Separation Group; Chemistry Department and Life Science Interface Group; Tyndall National Institute; University College Cork; Cork Ireland
| |
Collapse
|
13
|
Xia W, Nikitichev DI, Mari JM, West SJ, Pratt R, David AL, Ourselin S, Beard PC, Desjardins AE. Performance characteristics of an interventional multispectral photoacoustic imaging system for guiding minimally invasive procedures. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:86005. [PMID: 26263417 PMCID: PMC5217184 DOI: 10.1117/1.jbo.20.8.086005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 07/15/2015] [Indexed: 05/20/2023]
Abstract
Precise device guidance is important for interventional procedures in many different clinical fields including fetal medicine, regional anesthesia, interventional pain management, and interventional oncology. While ultrasound is widely used in clinical practice for real-time guidance, the image contrast that it provides can be insufficient for visualizing tissue structures such as blood vessels, nerves, and tumors. This study was centered on the development of a photoacoustic imaging system for interventional procedures that delivered excitation light in the ranges of 750 to 900 nm and 1150 to 1300 nm, with an optical fiber positioned in a needle cannula. Coregistered B-mode ultrasound images were obtained. The system, which was based on a commercial ultrasound imaging scanner, has an axial resolution in the vicinity of 100 μm and a submillimeter, depth-dependent lateral resolution. Using a tissue phantom and 800 nm excitation light, a simulated blood vessel could be visualized at a maximum distance of 15 mm from the needle tip. Spectroscopic contrast for hemoglobin and lipids was observed with ex vivo tissue samples, with photoacoustic signal maxima consistent with the respective optical absorption spectra. The potential for further optimization of the system is discussed.
Collapse
Affiliation(s)
- Wenfeng Xia
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
- Address all correspondence to: Wenfeng Xia,
| | - Daniil I. Nikitichev
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Jean Martial Mari
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Simeon J. West
- University College Hospital, Department of Anaesthesia, Main Theatres, Maple Bridge Link Corridor, Podium 3, 235 Euston Road, London NW1 2BU, United Kingdom
| | - Rosalind Pratt
- University College London, Institute for Women’s Health, 86-96 Chenies Mews, London WC1E 6HX, United Kingdom
| | - Anna L. David
- University College London, Institute for Women’s Health, 86-96 Chenies Mews, London WC1E 6HX, United Kingdom
| | - Sebastien Ourselin
- University College London, Center for Medical Imaging Computing, Gower Street, London WC1E 6BT, United Kingdom
| | - Paul C. Beard
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Adrien E. Desjardins
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| |
Collapse
|
14
|
Fiber-needle Swept-source Optical Coherence Tomography System for the Identification of the Epidural Space in Piglets. Anesthesiology 2015; 122:585-94. [DOI: 10.1097/aln.0000000000000531] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Abstract
Background:
Epidural needle insertion is traditionally a blind technique whose success depends on the experience of the operator. The authors describe a novel method using a fiber-needle–based swept-source optical coherence tomography (SSOCT) to identify epidural space.
Methods:
An optical fiber probe was placed into a hollow 18-gauge Tuohy needle. It was then inserted by an experienced anesthesiologist to continuously construct a series of two-dimensional SSOCT images by mechanically rotating the optical probe. To quantify this observation, both the average SSOCT signal intensities and their diagnostic potentials were assessed. The insertions were performed three times into both the lumbar and thoracic regions of five pigs using a paramedian approach.
Results:
A side-looking SSOCT is constructed to create a visual image of the underlying structures. The image criteria for the identification of the epidural space from the outside region were generated by the analysis of a training set (n = 100) of ex vivo data. The SSOCT image criteria for in vivo epidural space identification are high sensitivity (0.867 to 0.965) and high specificity (0.838 to 0.935). The mean value of the average signal intensities exhibits statistically significant differences (P < 0.01) and a high discriminatory capacity (area under curve = 0.88) between the epidural space and the outside tissues.
Conclusions:
This is the first study to introduce a SSOCT fiber probe embedded in a standard epidural needle. The authors anticipate that this technique will reduce the occurrence of failed epidural blocks and other complications such as dural punctures.
Collapse
|
15
|
Tang Q, Liang CP, Wu K, Sandler A, Chen Y. Real-time epidural anesthesia guidance using optical coherence tomography needle probe. Quant Imaging Med Surg 2015; 5:118-24. [PMID: 25694961 DOI: 10.3978/j.issn.2223-4292.2014.11.28] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 10/31/2014] [Indexed: 11/14/2022]
Abstract
Epidural anesthesia is one of the most widely used anesthesia methods. Due to lack of visual feedback to guide needle navigation, failure rate of epidural anesthesia is up to 20%, and the complication rate of peripheral nerve block approaches 10%, with the potential of permanent nerve damage. To address these difficulties, needle insertion under ultrasound guidance and fluoroscopy has been introduced. However, they do not provide adequate resolution and contrast to distinguish the tissue layers that the needle travels through or to specifically identify the epidural space. To improve the accuracy of epidural space identification, we developed a small hand-held optical coherence tomography (OCT) forward-imaging needle device for real-time epidural anesthesia surgery guidance and demonstrated its feasibility through ex vivo and in vivo animal experiments. With tissue structures visualized and differentiated at the needle tip, OCT needle imaging device will enhance clinical outcomes with regards to complication rates, induced pain, and procedure failure when compared to standard practice. Furthermore, this technology could be used in combination with ultrasound/fluoroscopy to enhance outcomes.
Collapse
Affiliation(s)
- Qinggong Tang
- 1 Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA ; 2 Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington D.C. 20010, USA
| | - Chia-Pin Liang
- 1 Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA ; 2 Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington D.C. 20010, USA
| | - Kyle Wu
- 1 Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA ; 2 Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington D.C. 20010, USA
| | - Anthony Sandler
- 1 Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA ; 2 Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington D.C. 20010, USA
| | - Yu Chen
- 1 Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA ; 2 Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Medical Center, Washington D.C. 20010, USA
| |
Collapse
|
16
|
Gong CSA, Lin SP, Mandell MS, Tsou MY, Chang Y, Ting CK. Portable optical epidural needle-a CMOS-based system solution and its circuit design. PLoS One 2014; 9:e106055. [PMID: 25162150 PMCID: PMC4146568 DOI: 10.1371/journal.pone.0106055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/26/2014] [Indexed: 11/19/2022] Open
Abstract
Epidural anesthesia is a common anesthesia method yet up to 10% of procedures fail to provide adequate analgesia. This is usually due to misinterpreting the tactile information derived from the advancing needle through the complex tissue planes. Incorrect placement also can cause dural puncture and neural injury. We developed an optic system capable of reliably identifying tissue planes surrounding the epidural space. However the new technology was too large and cumbersome for practical clinical use. We present a miniaturized version of our optic system using chip technology (first generation CMOS-based system) for logic functions. The new system was connected to an alarm that was triggered once the optic properties of the epidural were identified. The aims of this study were to test our miniaturized system in a porcine model and describe the technology to build this new clinical tool. Our system was tested in a porcine model and identified the epidural space in the lumbar, low and high thoracic regions of the spine. The new technology identified the epidural space in all but 1 of 46 attempts. Experimental results from our fabricated integrated circuit and animal study show the new tool has future clinical potential.
Collapse
Affiliation(s)
- Cihun-Siyong Alex Gong
- Department of Electrical Engineering, School of Electrical and Computer Engineering, College of Engineering, Chang Gung University, Taoyuan, Taiwan
- Portable Energy System Group, Green Technology Research Center, College of Engineering, Chang Gung University, Taoyuan, Taiwan
| | - Shih-Pin Lin
- Department of Anesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan
| | - M. Susan Mandell
- Department of Anesthesiology, University of Colorado Health Sciences Center, Aurora, Colorado, United States of America
| | - Mei-Yung Tsou
- Department of Anesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan
| | - Yin Chang
- Institute of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan
| | - Chien-Kun Ting
- Department of Anesthesiology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan
- * E-mail:
| |
Collapse
|
17
|
Soto-Astorga RP, West S, Putnis S, Hebden JC, Desjardins AE. Epidural catheter with integrated light guides for spectroscopic tissue characterization. BIOMEDICAL OPTICS EXPRESS 2013; 4:2619-2628. [PMID: 24298420 PMCID: PMC3829555 DOI: 10.1364/boe.4.002619] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 08/27/2013] [Indexed: 06/02/2023]
Abstract
Epidural catheters are used to deliver anesthetics and opioids for managing pain in many clinical scenarios. Currently, epidural catheter insertion is performed without information about the tissues that are directly ahead of the catheter. As a result, the catheter can be incorrectly positioned within a blood vessel, which can cause toxicity. Recent studies have shown that optical reflectance spectroscopy could be beneficial for guiding needles that are used to insert catheters. In this study, we investigate the whether this technique could benefit the placement of catheters within the epidural space. We present a novel optical epidural catheter with integrated polymer light guides that allows for optical spectra to be acquired from tissues at the distal tip. To obtain an initial indication of the information that could be obtained, reflectance values and photon penetration depth were estimated using Monte Carlo simulations, and optical reflectance spectra were acquired during a laminectomy of a swine ex vivo. Large differences between the spectra acquired from epidural adipose tissue and from venous blood were observed. The optical catheter has the potential to provide real-time detection of intravascular catheter placement that could reduce the risk of complications.
Collapse
Affiliation(s)
- R. P. Soto-Astorga
- Department of Medical Physics and Bioengineering, University College London, London, UK
| | - S. West
- Department of Anaesthesia, University College Hospital, London, UK
| | - S. Putnis
- Department of Orthopaedics, University College Hospital, London, UK
| | - J. C. Hebden
- Department of Medical Physics and Bioengineering, University College London, London, UK
| | - A. E. Desjardins
- Department of Medical Physics and Bioengineering, University College London, London, UK
| |
Collapse
|
18
|
Mhyre JM. Why do pharmacologic test doses fail to identify the unintended intrathecal catheter in obstetrics? Anesth Analg 2012; 116:4-5. [PMID: 23264171 DOI: 10.1213/ane.0b013e318273f625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
19
|
|
20
|
|