Denne siden ble automatisk oversatt og nøyaktigheten av oversettelsen er ikke garantert. Vennligst referer til engelsk versjon for en kildetekst.

The Effect of Blood Pressure on Cerebral Perfusion During Vascular Surgery

26. september 2017 oppdatert av: Niels Damkjær Olesen, Rigshospitalet, Denmark

The Effect of Blood Pressure on Cerebral Perfusion and Oxygenation During Vascular Surgery

Anesthesia reduces blood pressure and cerebral blood flow is normally considered to be maintained despite marked changes in blood pressure. Vascular surgical patients are often elderly, have high blood pressure and atherosclerosis and in these patients cerebral blood flow may decrease if blood pressure is reduced during anesthesia. The purpose of this study is to assess the effect of blood pressure for preservation of cerebral blood flow during anesthesia in vascular surgery. The hypothesis is that in vascular surgical patients, during anesthesia, cerebral blood flow is higher with blood pressure maintained at a higher level than that used in normal clinical practice.

Studieoversikt

Status

Tilbaketrukket

Forhold

Intervensjon / Behandling

Detaljert beskrivelse

Background: Induction of anesthesia reduces mean arterial pressure (MAP) and cerebral blood flow is normally considered to be maintained by cerebral autoregulation despite changes in MAP between 60 - 150 mmHg and standard of care during anesthesia is to maintain MAP above 60 mmHg. Vascular surgical patients are often elderly with hypertension and atherosclerotic manifestations that may impair cerebral autoregulation of importance for anesthesia-induced reduction in blood pressure.

Objective: To assess the effect of MAP for preservation of cerebral blood flow and oxygenation during vascular surgery.

Hypothesis: The primary hypothesis is that during general anesthesia in vascular surgical patients, cerebral blood flow velocity and oxygenation is higher with MAP maintained at 80-90 mmHg, compared with a MAP maintained at a minimum of 60 mmHg.

MAP is controlled in both groups using continuous infusion of phenylephrine. Phenylephrine is used as a tool in order to assess the effect of MAP on the cerebral circulation. In both groups, central blood volume is optimized by infusion of lactated Ringer´s solution using a goal directed fluid therapy following induction of anaesthesia and before commencement of phenylephrine infusion.

Trial size: The investigators will include 40 participants (2 x 20) in order to detect or reject a 20% difference in middle cerebral artery velocity with a type I error risk of 5% and a type II error risk of 20% (power at 80%). Interim analysis will be conducted after inclusion of 20 patients (2 x 10). Excluded patients will be replaced.

Studietype

Intervensjonell

Fase

  • Ikke aktuelt

Kontakter og plasseringer

Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.

Studiesteder

  • Danmark
      • Copenhagen Ø, Danmark, 2100
        • Rigshospitalet, Anæstesi og Operationsklinikken 2043

Deltakelseskriterier

Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.

Kvalifikasjonskriterier

Alder som er kvalifisert for studier

19 år og eldre (Voksen, Eldre voksen)

Tar imot friske frivillige

Nei

Kjønn som er kvalifisert for studier

Alle

Beskrivelse

Inclusion Criteria:

  • Patients undergoing one of the following vascular surgical interventions in general anesthesia: Infra-inguinal bypass, femoro-femoral cross-over bypass or iliofemoral bypass surgery.
  • Age > 18 years. Informed consent

Exclusion Criteria:

  • Use of monoamine oxidase inhibitors
  • Allergy to phenylephrine
  • Patients that cannot cooperate during examination
  • Dementia defined as Mini-Mental State Examination < 24
  • Anesthesia within the last 30 days
  • Alcohol consumption at or above 420 grams per week
  • Lack of fluency in written and spoken Danish
  • Severe hearing and vision impairment
  • Neurological disease

Studieplan

Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.

Hvordan er studiet utformet?

Designdetaljer

  • Primært formål: Støttende omsorg
  • Tildeling: Randomisert
  • Intervensjonsmodell: Parallell tildeling
  • Masking: Trippel

Våpen og intervensjoner

Deltakergruppe / Arm
Intervensjon / Behandling
Eksperimentell: MAP maintained at 80 mmHg
During anesthesia MAP is maintained at 80 - 90 mmHg MAP using continuous infusion of phenylephrine.
Annen: MAP maintained at 80 mmHg
Intervention group, MAP is maintained at 80 - 90 mmHg during anesthesia using continuous infusion of phenylephrine.
Aktiv komparator: MAP maintained at 60 mmHg
During anesthesia MAP is maintained at minimum of 60 mmHg using continuous infusion of phenylephrine.
Annen: MAP maintained at 60 mmHg
Control group, MAP is maintained at minimum of 60 mmHg during anesthesia using continuous infusion of phenylephrine.

Hva måler studien?

Primære resultatmål

Resultatmål
Tiltaksbeskrivelse
Tidsramme
Middle cerebral artery blood velocity
Tidsramme: During surgery
Middle cerebral artery blood velocity measured in [cm/s] assessed by transcranial Doppler. Changes in middle cerebral artery blood velocity reflects changes in cerebral blood flow.
During surgery

Sekundære resultatmål

Resultatmål
Tiltaksbeskrivelse
Tidsramme
Change in serum S100B as compared between subjects in the control- and intervention groups
Tidsramme: Blood is sampled 10 min prior to induction of anesthesia and at the end of surgery
Serum concentrations of S100B, a marker of neuronal injury
Blood is sampled 10 min prior to induction of anesthesia and at the end of surgery
Change in serum neuron-specific enolase as compared between subjects in the control- and intervention groups
Tidsramme: Blood is sampled 10 min prior to induction of anesthesia and at the end of surgery
Serum concentrations of neuron-specific enolase, a marker of neuronal injury
Blood is sampled 10 min prior to induction of anesthesia and at the end of surgery
Regional cerebral oxygenation as compared between subjects in the control- and intervention groups
Tidsramme: During surgery
Frontal lobe oxygenation measured as the percentage of oxyhemoglobin of total hemoglobin [%] evaluated by near-infrared spectroscopy
During surgery
Cardiac output as compared between subjects in the control- and intervention groups
Tidsramme: During surgery
Cardiac output measured in [l/min] evaluated by pulse contour analysis of the arterial blood pressure curve
During surgery
Stroke volume as compared between subjects in the control- and intervention groups
Tidsramme: During surgery
Stroke volume measured in [ml/min] evaluated by pulse contour analysis of the arterial blood pressure curve
During surgery

Samarbeidspartnere og etterforskere

Det er her du vil finne personer og organisasjoner som er involvert i denne studien.

Sponsor

Rigshospitalet, Denmark

Etterforskere

  • Hovedetterforsker: Niels D. Olesen, MD, Rigshospitalet, Anæstesi og Operationsklinikken 2043, Denmark

Studierekorddatoer

Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.

Studer hoveddatoer

Studiestart (Forventet)

1. mars 2017

Primær fullføring (Forventet)

1. november 2017

Studiet fullført (Forventet)

1. november 2017

Datoer for studieregistrering

Først innsendt

14. august 2015

Først innsendt som oppfylte QC-kriteriene

20. august 2015

Først lagt ut (Anslag)

24. august 2015

Oppdateringer av studieposter

Sist oppdatering lagt ut (Faktiske)

28. september 2017

Siste oppdatering sendt inn som oppfylte QC-kriteriene

26. september 2017

Sist bekreftet

1. september 2017

Mer informasjon

Begreper knyttet til denne studien

Nøkkelord

Ytterligere relevante MeSH-vilkår

Andre studie-ID-numre

  • NDOlesen

Legemiddel- og utstyrsinformasjon, studiedokumenter

Studerer et amerikansk FDA-regulert medikamentprodukt

Nei

Studerer et amerikansk FDA-regulert enhetsprodukt

Nei

produkt produsert i og eksportert fra USA

Nei

Denne informasjonen ble hentet direkte fra nettstedet clinicaltrials.gov uten noen endringer. Hvis du har noen forespørsler om å endre, fjerne eller oppdatere studiedetaljene dine, vennligst kontakt register@clinicaltrials.gov. Så snart en endring er implementert på clinicaltrials.gov, vil denne også bli oppdatert automatisk på nettstedet vårt. .

Abonnere