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Cerebral Blood Flow During Propofol Anaesthesia

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ClinicalTrials.gov Identifier: NCT02951273
Recruitment Status : Completed
First Posted : November 1, 2016
Results First Posted : November 17, 2017
Last Update Posted : January 17, 2018
Sponsor:
Information provided by (Responsible Party):
Niels Damkjær Olesen, Rigshospitalet, Denmark

Brief Summary:

General anaesthesia often reduces blood pressure whereby blood flow to the brain and other vital organs may become insufficient. Thus, medicine is often administered during anaesthesia to maintain blood pressure. However, it is unclear at what level blood pressure should be aimed at during anaesthesia.

Several factors may affect blood flow to the brain during anaesthesia. During surgery on the internal organs, a hormone may be released that dilates blood vessels and causes a so-called mesenteric traction syndrome characterised by a decrease in blood pressure and flushing. This reaction lasts for approximately thirty minutes and is observed in about half of the patients who undergo surgery on the stomach and intestines. It is unknown whether a mesenteric traction syndrome affects blood flow to the brain. Ventilation is also of importance for blood flow to the brain. Thus, blood flow to the brain is reduced by hyperventilation and increases if breathing is slower. It is unclear whether the relation between blood flow to the brain and ventilation is affected during anaesthesia.

This study will evaluate how blood flow to the brain is affected by anaesthesia and standard treatment of a possible reduction in blood pressure. Further, the study will assess whether blood flow to the brain is affected by development of a mesenteric traction syndrome. Lastly, the project will evaluate blood flow to the brain during short-term changes in the patient's ventilation by adjustments on the ventilator.

Thirty patients planned for major abdominal surgery will be included in the project. The study will take place from the patient's arrival at the operation room and until two hours after the start of surgery. Placement of catheters and anaesthesia are according to standard care. Blood flow to the brain will be evaluated using ultrasound. Oxygenation of the brain, skin and muscle will be evaluated by probes that emit light. Depth of anaesthesia is assessed by recording the electrical activity of the brain. Blood pressure is measured by a catheter placed in an artery at the wrist and blood samples will be drawn from the catheter.


Condition or disease Intervention/treatment
Gastrointestinal Neoplasms Other: Study of cerebral blood flow

  Show Detailed Description

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Study Type : Observational
Actual Enrollment : 30 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Cerebral Blood Flow During Propofol Anaesthesia
Actual Study Start Date : December 8, 2016
Actual Primary Completion Date : July 6, 2017
Actual Study Completion Date : July 6, 2017

Resource links provided by the National Library of Medicine

Drug Information available for: Propofol

Group/Cohort Intervention/treatment
Study of cerebral blood flow
Patients undergoing oesophageal- or ventricular resection (n=30)
Other: Study of cerebral blood flow

Measurements are conducted from before induction of anaesthesia and until 2 hours after the start of surgery and include internal carotid artery blood flow, mean arterial pressure, heart rate, stroke volume, cardiac output, total peripheral resistance, forehead skin blood flow and haemoglobin concentrations, depth of anaesthesia, and frontal lobe, skin, and muscle oxygenation. Further measurements are conducted during hyperventilation before induction of anaesthesia and during hypo-, normo- and hypercapnia during anaesthesia.

Blood samples are obtained from the arterial line for evaluation of the arterial CO2 tension and markers of mesenteric traction syndrome. Total volume of blood sampled is less than 75 ml.





Primary Outcome Measures :
  1. Changes in Internal Carotid Artery Blood Flow by Treatment of Anaesthesia-induced Hypotension [ Time Frame: Two measurements; one measurement during anaesthesia-induced hypotension (mean arterial pressure < 65 mmHg) before administration of phenylephrine and one measurement 3-5 min after administration of phenylephrine. ]
    Unilateral internal carotid artery blood flow [ml/min] assessed by duplex ultrasound.


Secondary Outcome Measures :
  1. Changes in Internal Carotid Artery Blood Flow by Induction of Anaesthesia. [ Time Frame: Two measurements; one measurement 5-10 min before induction of anaesthesia and one measurement 5-20 min after induction of anaesthesia. ]
    Unilateral internal carotid artery blood flow [ml/min] assessed by duplex ultrasound.

  2. Association by Multiple Regression Between Changes in Internal Carotid Artery Blood Flow, Mean Arterial Pressure and Cardiac Output by Treatment of Anaesthesia-induced Hypotension. [ Time Frame: Two measurements; one measurement during anaesthesia-induced hypotension (mean arterial pressure < 65 mmHg) before administration of phenylephrine and one measurement 3-5 min after administration of phenylephrine. ]

    Association by multiple regression between changes in unilateral internal carotid artery blood flow [ml/min] as outcome variable and changes in mean arterial pressure [mmHg] and cardiac output [l/min] as covariates.

    Internal carotid artery blood flow [ml/min] was assessed by duplex ultrasound. Mean arterial pressure [mmHg] was recorded by a transducer connected to an arterial line. Cardiac output [l/min] was evaluated by pulse contour analysis (Modelflow) that estimates cardiac output by analysis of the arterial pressure curve taking age, gender, height and weigth into account.


  3. Changes in Frontal Lobe Oxygenation by Development of Mesenteric Traction Syndrome (MTS). [ Time Frame: Six measurements during anaesthesia; 5 min before and after incision and 0, 20, 40, and 70 min after flushing and 20, 40, 60, and 90 min after the start of surgery in those patients who do not develop mesenteric traction syndrome. ]
    Near-infrared spectroscopy determined frontal lobe oxygenation [%] as compared between those patients who develop a MTS (defined as flushing within 60 min after the start of surgery) and those who do not. An effect of a MTS was evaluated by a repeated measure mixed model with the fixed effects time point, group according to development of MTS, and interaction between time and group. The reported result is the interaction factor for the time point 0 min after flushing and 20 min after the start of surgery in patients who did not develop MTS.

  4. Changes in Forehead Skin Blood Flow by Development of Mesenteric Traction Syndrome (MTS). [ Time Frame: Six measurements during anaesthesia; 5 min before and after incision and 0, 20, 40, and 70 min after flushing and 20, 40, 60, and 90 min after the start of surgery in those patients who do not develop mesenteric traction syndrome. ]
    Forehead skin blood flow [PU] assessed by laser Doppler flowmetry as compared between those patients who develop mesenteric traction syndrome (defined as flushing within 60 min after the start of surgery) and those who do not. Laser Doppler flowmetry applies a laser placed on the forehead that penetrates the skin and is scattered with a Doppler shift by the red blood cells and return to a detector that evaluates the amount of backscattered light and Doppler shift. An effect of a MTS was evaluated by a repeated measure mixed model with the fixed effects time point, group according to development of MTS, and interaction between time and group. The reported result is the interaction factor for the time point 0 min after flushing and 20 min after the start of surgery in patients who did not develop MTS.

  5. Changes in Forehead Skin Oxygenation by Development of Mesenteric Traction Syndrome (MTS). [ Time Frame: Six measurements during anaesthesia; 5 min before and after incision and 0, 20, 40, and 70 min after flushing and 20, 40, 60, and 90 min after the start of surgery in those patients who do not develop mesenteric traction syndrome. ]
    Forehead skin oxygenation [%] assessed by laser Doppler flowmetry as compared between those patients who develop a MTS (defined as flushing within 60 min after the start of surgery) and those who do not. An effect of a MTS was evaluated by a repeated measure mixed model with the fixed effects time point, group according to development of MTS, and interaction between time and group. The reported result is the interaction factor for the time point 0 min after flushing and 20 min after the start of surgery in patients who did not develop MTS.

  6. Changes in Internal Carotid Artery Blood Flow by Development of Mesenteric Traction Syndrome (MTS). [ Time Frame: Six measurements during anaesthesia; 5 min before and after incision and 0, 20, 40, and 70 min after flushing and 20, 40, 60, and 90 min after the start of surgery in those patients who do not develop mesenteric traction syndrome. ]
    Unilateral internal carotid artery blood flow [ml/min] assessed by duplex ultrasound as compared between those patients who develop a MTS (defined as flushing within 60 min after the start of surgery) and those who do not. An effect of a MTS was evaluated by a repeated measure mixed model with the fixed effects time point, group according to development of MTS, and interaction between time and group. The reported result is the interaction factor for the time point 0 min after flushing and 20 min after the start of surgery in patients who did not develop MTS.

  7. Changes in the CO2 Reactivity of the Internal Carotid Artery From Before to After Induction of Anaesthesia. [ Time Frame: Four measurements; before induction of anaesthesia during normoventilation and during hyperventilation to reduce PaCO2 by 1.5 kPa and during anaesthesia at a PaCO2 at the value before induction of anaesthesia and 1.5 kPa below that value. ]

    Unilateral internal carotid artery blood flow [ml/min] assessed by duplex ultrasound and arterial CO2 tension (PaCO2) [kPa] was evaluated by gas analysis. Changes in PaCO2 are guided by evaluation of end-tidal CO2 tension.

    The CO2 reactivity to hypocapnia when awake and during anaesthesia is calculated as the percentage change in internal carotid artery blood flow per kPa change in PaCO2. The CO2 reactivity when awake and when anaesthetized is compared.


  8. Changes in Heart Rate From Baseline Before Induction of Anaesthesia. [ Time Frame: Continuous measurements from before induction of anaesthesia and until 2 hours after start of surgery. ]
    Heart rate [bpm] as recorded continuously by a transducer connected to an arterial line.

  9. Changes in Mean Arterial Pressure From Baseline Before Induction of Anaesthesia. [ Time Frame: Continuous measurements from before induction of anaesthesia and until 2 hours after start of surgery. ]
    Mean arterial pressure [mmHg] as recorded continuously by a transducer connected to an arterial line.

  10. Changes in Cardiac Output From Baseline Before Induction of Anaesthesia. [ Time Frame: Continuous measurements from before induction of anaesthesia and until 2 hours after start of surgery. ]
    Cardiac output [l/min] as evaluated continuously by pulse contour analysis of the arterial pressure curve (Modelflow).

  11. Changes in Stroke Volume From Baseline Before Induction of Anaesthesia. [ Time Frame: Continuous measurements from before induction of anaesthesia and until 2 hours after start of surgery. ]
    Stroke volume [ml] as evaluated continuously by pulse contour analysis of the arterial pressure curve (Modelflow).


Biospecimen Retention:   Samples Without DNA
Plasma


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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Thirty patients planned for oesophageal- or ventricular resection at Department of Anaesthesia, Rigshospitalet, Copenhagen, Denmark
Criteria

Inclusion Criteria:

  • Patients planned for major abdominal surgery that require placement of an arterial line and central venous catheter, including oesophageal- or ventricular resection
  • Age ≥ 18 years.

Exclusion Criteria:

  • No informed consent
  • Robotic assisted procedures
  • Treatment with anti-inflammatory medication, including NSAID and corticosteroids
  • Atherosclerosis of the internal carotid artery that obstructs ≥ 30% of the vessel lumen
  • Neurologic disease considered to affect cerebral blood flow, including dementia, epilepsy, and apoplexy

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02951273


Locations
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Denmark
Department of Anaesthesia, Rigshospitalet 2043
Copenhagen, Denmark, 2300
Sponsors and Collaborators
Rigshospitalet, Denmark
Investigators
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Study Director: Niels H. Secher, MD, D.M.Sc. Department of Anaesthesia, Rigshospitalet 2043, DK-2100 Copenhagen Ø, Denmark
Principal Investigator: Niels D. Olesen, MD Department of Anaesthesia, Rigshospitalet 2043, DK-2100 Copenhagen Ø, Denmark
  Study Documents (Full-Text)

Documents provided by Niels Damkjær Olesen, Rigshospitalet, Denmark:
Study Protocol  [PDF] November 19, 2017
Statistical Analysis Plan  [PDF] November 19, 2017


Publications:

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Responsible Party: Niels Damkjær Olesen, MD, Rigshospitalet, Denmark
ClinicalTrials.gov Identifier: NCT02951273     History of Changes
Other Study ID Numbers: H-16036250
First Posted: November 1, 2016    Key Record Dates
Results First Posted: November 17, 2017
Last Update Posted: January 17, 2018
Last Verified: December 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by Niels Damkjær Olesen, Rigshospitalet, Denmark:
abdominal surgery
blood pressure
cardiac output
cerebral blood flow
cerebral oxygenation
CO2 reactivity
duplex ultrasound
general anaesthesia
mesenteric traction syndrome
near-infrared spectroscopy
upper gastrointestinal cancer surgery
Additional relevant MeSH terms:
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Gastrointestinal Neoplasms
Digestive System Neoplasms
Neoplasms by Site
Neoplasms
Digestive System Diseases
Gastrointestinal Diseases
Anesthetics
Propofol
Central Nervous System Depressants
Physiological Effects of Drugs
Hypnotics and Sedatives
Anesthetics, Intravenous
Anesthetics, General