Udvikling af en algoritme til at udføre en omfattende undersøgelse af autonom dysrefleksi i Dyr med høj Rygmarvsskader Brug af en Telemetri Device
Summary
The catheter of a telemetry device is implanted into the abdominal aorta in order to continuously collect beat-by-beat hemodynamic data from animals pre and post-high thoracic spinal cord transection. A novel JAVA software was employed to analyze hemodynamic parameters as well as frequency and intensity of spontaneous episodes of autonomic dysreflexia.
Abstract
Spinal cord injury (SCI) is a debilitating neurological condition characterized by somatic and autonomic dysfunctions. In particular, SCI above the mid-thoracic level can lead to a potentially life-threatening hypertensive condition called autonomic dysreflexia (AD) that is often triggered by noxious or non-noxious somatic or visceral stimuli below the level of injury. One of the most common triggers of AD is the distension of pelvic viscera, such as during bladder and bowel distension or evacuation. This protocol presents a novel pattern recognition algorithm developed for a JAVA platform software to study the fluctuations of cardiovascular parameters as well as the number, severity and duration of spontaneously occurring AD events. The software is able to apply a pattern recognition algorithm on hemodynamic data such as systolic blood pressure (SBP) and heart rate (HR) extracted from telemetry recordings of conscious and unrestrained animals before and after thoracic (T3) complete transection. With this software, hemodynamic parameters and episodes of AD are able to be detected and analyzed with minimal experimenter bias.
Introduction
Autonom dysrefleksi (AD) er en livstruende nødsituation i individer efter akut eller kronisk rygmarvsskade (SCI) på livmoderhalsen eller høje-thorax segmenter og er normalt karakteriseret ved episoder af vedvarende hypertension og bradykardi 1. AD er hovedsagelig forårsaget af afbrydelse af faldende spinal veje, der normalt giver input fra supraspinale centre til spinal sympatiske præganglioniske neuroner, der styrer sympatisk aktivitet og vaskulær tone 1-4. AD episoder er kendetegnet ved en stigning i det systoliske blodtryk (SBP) op til 300 mmHg, og hvis venstre ubehandlet kan føre til anfald, hjerneblødning, myokardieinfarkt, og endda død 5-8. En række skadelige og ikke-skadelige stimuli fungere som en udløser af AD, herunder tarm og blære udspiling, krampe, tryksår, urinblære kateterisation eller iatrogene procedurer 9-12.
Den tidsmæssige udvikling af AD i hhvonse til SCI er blevet undersøgt i både humane 9 og dyremodeller 13,14. Disse undersøgelser har typisk brugt en "induceret AD 'metode (dvs. urodynamikken, penis vibrostimulations i mennesker eller colorectal distension hos dyr) for at bestemme den tidsmæssige udvikling af AD. En sådan tilgang er begrænset af behovet for gentagne vurderinger på isolerede tidspunkter, der kan udelukke en nøjagtig bestemmelse af den tidsmæssige udvikling af AD. Brugen af 24-timers blodtryksmåling hos mennesker giver seriel blodtryksmålinger skal foretages ved forudbestemte intervaller. Denne teknik er for nylig blevet anvendt til at overvåge spontant forekommende AD hos patienter med kronisk SCI. I dyremodeller, er solid-state tryktransducere bliver i stigende grad brugt til kronisk overvåge slå-by-slå arterielle blodtryk. For nylig Rabchesvky et al. (2012), udviklet en algoritme, der udvindes et sekund gennemsnit af gennemsnitligt arterielt tryk (MAP) end sammenlignet med en glidende gennemsnit tærskel 15. Spontane AD hændelser blev karakteriseret baseret på MAP toppe, der er 10 mmHg eller mere over grænsen i takt med en HR-fald på 10 bpm eller mere.
Her en roman JAVA software, der har en indbygget AD Detection Algoritme præsenteres. Denne algoritme virker ved at detektere forudbestemte mønstre i arterielt blodtryk (ABP) og hjertefrekvens (HR), der er indikative for en spontant forekommende AD begivenhed. Brugeren er i stand til manuelt at justere alle inputvariabler til den software, således at den "afsløring algoritme" kan let tilpasses til de specifikke parametre af interesse. Softwaren er også i stand til dichotomize ABP og HR i en given epoke, således at døgnets rytme af hæmodynamiske parametre kan analyseres 16. I den foreliggende manuskript, er en detaljeret forklaring af den kirurgiske teknik, der bruges til at implantere telemetri-enheder og udfører SCI kirurgi. Exsempler er også med hensyn til de post-databehandling af AD Detection software og hvordan kardiovaskulære funktion ændres post-SCI. Til sammenligning, den metode og resultater fra en metode induceret AD kendt som kolorektal distension (CRD) er også illustreret.
Protocol
Representative Results
Discussion
Protokollen beskriver en detaljeret gennemførelse af en ny JAVA platform AD Detection software, som vil blive kombineret med en telemetri enhed, for en langsigtet grundig analyse af ABP i sci-dyr (Figur 1B). Dette er den første software, der muliggør karakteriseringen af ABP mønstre til at detektere spontane AD begivenheder, som de opstår sporadisk under hele dagen. Et godt karakteriseret T3 SCI dyremodel kan illustrere den funktionelle kapacitet af software til at registrere frekvensen, pres…
Divulgazioni
The authors have nothing to disclose.
Acknowledgements
Denne forskning, hvis finansieret af den canadiske Institute of Health Research og hjerte og Stroke Foundation of BC og Yukon. Vi vil gerne anerkende Mr. Rayshad Gopaul og Dr. Shelly McErlane for tekniske støtte og ekspertise i dyr pleje.
Materials
| 11 Male Wistar Rats -Hsd-WI (250-300g) | Envigo (formerly Harlan Laboratories) | 141 | |
| Lab Chart (PowerLab® Data Acquisition System) | AD Instruments | ||
| Pressure Telemeter | Millar Inc. | RP-TRM54P | |
| Configurator | Millar Inc. | TR190 | |
| SmartPad | Millar Inc. | TR180 | |
| Isoflurane (Aerrane) | Baxter Corp. | DIN: 02225875 | |
| Enrofloxacin (Baytril) | Bayer Healthcare | DIN: 02169428 | |
| 5-0 Silk Sutures | Ethicon | S182 | |
| 4-0 Vicryl Subcuticular | Ethicon | J496G | |
| Buprenorphine (Temgesic) | Reckitt Benckiser | DIN: 0281250 | |
| Bupivicaine Hydrochloride (Marcaine 0.5%) | Hospira Healthcare Corp. | DIN: 02305909 | |
| Ketoprofen (Anafen) | Merial | DIN: 02150999 | |
| Ketamine Hydrochloride (Vetalar) | Bioniche | DIN: 01989529 | |
| Dexmedetomidine Hydrochloride (Domitor) | Pfizer | DIN: 02333929 | |
| Lactated Ringer's Solution | Braun Medical Inc. | DIN: 01931636 | |
| Gelfoam #12 | Pharmacia & Upjohn Company | 03603-14-1 | |
| Microscissors | Fine Science Tools | 15003-008 | |
| Iris Spatulae | Fine Science Tools | 10094-13 | |
| 10 French 35cm Foley Catheter | Coloplast | AA6110 | |
| Dietgel® | Clear H2O, Westbrook, ME | 76A | |
| LabDiet Rodent Diet 5001 | Purina Mills (PMI®) | 5001 | |
| Chlorhexadine (Hibitane) | Wyeth Animal Health, Guelph, Ontario | DIN 00245097 | |
| Atipamezole Hydrochloride(Antisedan) | Orion Pharma | DIN: 02237744 |
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