NCT07399275

Brief Summary

During major surgical procedures performed under general anesthesia, changes in blood flow and oxygen delivery to tissues may occur due to blood loss, hemodynamic fluctuations, and anesthesia-related physiological effects. These changes can lead to impaired tissue perfusion, which is commonly reflected by increased arterial lactate levels. However, lactate measurements are intermittent and may not detect early perfusion abnormalities. This prospective observational study aims to investigate the relationship between submental tissue oxygenation measured by near-infrared spectroscopy (NIRS), microvascular reactivity assessed by the vascular occlusion test, and arterial lactate levels during major surgery. Adult patients undergoing major abdominal, neurosurgical, or orthopedic procedures will be monitored intraoperatively using non-invasive NIRS techniques, while arterial blood gas analyses will be performed as part of routine clinical care. The study does not involve any changes to standard anesthesia or surgical management. All treatments and clinical decisions will be made by the responsible care team according to routine practice. By evaluating non-invasive indicators of tissue oxygenation and microvascular function, this study aims to improve the understanding of early intraoperative tissue perfusion changes and their association with metabolic markers.

Trial Health

63
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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
150

participants targeted

Target at P50-P75 for all trials

Timeline
8mo left

Started Feb 2026

Shorter than P25 for all trials

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress33%
Feb 2026Feb 2027

First Submitted

Initial submission to the registry

February 3, 2026

Completed
7 days until next milestone

First Posted

Study publicly available on registry

February 10, 2026

Completed
5 days until next milestone

Study Start

First participant enrolled

February 15, 2026

Completed
1 year until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 15, 2027

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

February 15, 2027

Last Updated

February 10, 2026

Status Verified

February 1, 2026

Enrollment Period

1 year

First QC Date

February 3, 2026

Last Update Submit

February 3, 2026

Conditions

Keywords

tissue hypoperfusionmicrovascular circulationNear infrared spectroscopyvascular occlusionlactate blood increaseMajor surgery

Outcome Measures

Primary Outcomes (1)

  • Correlation between submental tissue oxygenation and arterial lactate levels

    The strength and direction of the association between intraoperative submental tissue oxygenation measured by near-infrared spectroscopy and arterial lactate levels during major surgery.

    Intraoperatively, from anesthesia induction to the end of surgery

Secondary Outcomes (3)

  • Correlation between microvascular reactivity and arterial lactate levels

    Intraoperatively, from anesthesia induction to the end of surgery

  • Intraoperative submental NIRS desaturation events

    Intraoperatively, from anesthesia induction to the end of surgery

  • Relationship between submental tissue oxygenation and microvascular reactivity

    Intraoperatively, from anesthesia induction to the end of surgery

Study Arms (1)

Major Surgery

Adult patients aged 18 years and older undergoing major surgical procedures under general anesthesia will be included in this cohort. Major surgery is defined as surgical procedures associated with a risk of significant blood loss and/or impaired tissue perfusion, requiring invasive arterial blood pressure monitoring and hourly arterial blood gas analysis. Eligible procedures include major abdominal, neurosurgical, and major orthopedic surgeries. All anesthetic and surgical management will be performed according to standard clinical practice. The study does not involve any experimental intervention or alteration of routine clinical care. Submental tissue oxygenation and microvascular reactivity will be monitored intraoperatively using non-invasive near-infrared spectroscopy techniques as part of observational data collection.

Other: No intervention. This is a prospective observational study. Near-infrared spectroscopy measurements are performed for monitoring purposes only and do not influence clinical management.

Interventions

This study does not include any therapeutic, diagnostic, or experimental intervention. It is a prospective observational study in which non-invasive near-infrared spectroscopy is used solely for intraoperative monitoring of submental tissue oxygenation and microvascular reactivity. Study measurements are collected for research purposes only and do not guide or alter anesthetic, surgical, or transfusion-related clinical decisions. All perioperative management is conducted according to standard institutional practice by the responsible clinical team.

Major Surgery

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

The study population consists of adult patients aged 18 years and older undergoing major surgical procedures under general anesthesia at a single tertiary care center. Major surgery includes abdominal, neurosurgical, and major orthopedic procedures associated with a risk of significant blood loss and/or impaired tissue perfusion, requiring invasive arterial blood pressure monitoring and hourly arterial blood gas analysis as part of routine clinical care. All participants are enrolled prospectively and monitored intraoperatively without any alteration to standard anesthetic or surgical management.

You may qualify if:

  • Adults aged 18 years and older
  • Scheduled for major surgical procedures under general anesthesia
  • Major surgery defined as procedures associated with a risk of significant blood loss and/or impaired tissue perfusion, requiring invasive arterial blood pressure monitoring and hourly arterial blood gas analysis
  • Planned intraoperative arterial catheter placement as part of routine clinical care
  • Ability to provide written informed consent

You may not qualify if:

  • Age younger than 18 years
  • Refusal or inability to provide informed consent
  • Absence of invasive arterial blood pressure monitoring
  • Known pregnancy
  • Severe peripheral vascular disease affecting upper extremities
  • Anatomical abnormalities or skin conditions preventing placement of NIRS sensors on the submental or thenar regions
  • Emergency surgery requiring immediate intervention
  • Preoperative severe metabolic acidosis (arterial pH \< 7.20)

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Health Sciences, Bursa Yuksek Ihtisas Training and Research Hospital

Bursa, Turkey (Türkiye)

Location

Related Publications (3)

  • Bakker J, Nijsten MW, Jansen TC. Clinical use of lactate monitoring in critically ill patients. Ann Intensive Care. 2013 May 10;3(1):12. doi: 10.1186/2110-5820-3-12.

    PMID: 23663301BACKGROUND
  • Gomez H, Mesquida J, Simon P, Kim HK, Puyana JC, Ince C, Pinsky MR. Characterization of tissue oxygen saturation and the vascular occlusion test: influence of measurement sites, probe sizes and deflation thresholds. Crit Care. 2009;13 Suppl 5(Suppl 5):S3. doi: 10.1186/cc8001. Epub 2009 Nov 30.

  • Scheeren TW, Schober P, Schwarte LA. Monitoring tissue oxygenation by near infrared spectroscopy (NIRS): background and current applications. J Clin Monit Comput. 2012 Aug;26(4):279-87. doi: 10.1007/s10877-012-9348-y. Epub 2012 Mar 31.

MeSH Terms

Conditions

Hyperlactatemia

Condition Hierarchy (Ancestors)

Metabolic DiseasesNutritional and Metabolic DiseasesSigns and SymptomsPathological Conditions, Signs and Symptoms

Study Officials

  • Korgün Ökmen

    Department of Anesthesiology and Reanimation, Bursa Yuksek Ihtisas Training and Research Hospital, University of Health Sciences, Bursa

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Study Design

Study Type
observational
Observational Model
COHORT
Time Perspective
PROSPECTIVE
Sponsor Type
OTHER GOV
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Consultant Anesthesiologist and Intensivist

Study Record Dates

First Submitted

February 3, 2026

First Posted

February 10, 2026

Study Start

February 15, 2026

Primary Completion (Estimated)

February 15, 2027

Study Completion (Estimated)

February 15, 2027

Last Updated

February 10, 2026

Record last verified: 2026-02

Data Sharing

IPD Sharing
Will not share

Locations