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Cerebral Blood Flow During Propofol Anaesthesia

NCT02951273 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 30

Last updated 2018-01-17

Study results available
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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.

Conditions

  • Gastrointestinal Neoplasms

Interventions

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.

Sponsors & Collaborators

  • Rigshospitalet, Denmark

    lead OTHER

Principal Investigators

  • Niels H. Secher, MD, D.M.Sc. · Department of Anaesthesia, Rigshospitalet 2043, DK-2100 Copenhagen Ø, Denmark

  • Niels D. Olesen, MD · Department of Anaesthesia, Rigshospitalet 2043, DK-2100 Copenhagen Ø, Denmark

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2016-12-08
Primary Completion
2017-07-06
Completion
2017-07-06

Countries

  • Denmark

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT02951273 on ClinicalTrials.gov