Is Permissive Hypotension Truly Harmless? Early Biomarker Evidence of Subclinical Kidney Injury in Rhinologic Surgery

NCT07328620 | Completed

• 1 other identifier: PerHypGU0820125
• Study Type: observational
• Target: 35
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate the effects of permissive hypotension, which is routinely used in rhinologic surgeries such as rhinoplasty, septoplasty, and functional endoscopic sinus surgery (FESS), on renal function. Although permissive hypotension has been widely practiced to improve surgical field visibility and reduce intraoperative blood loss, its specific definition is not standardized in the literature. In most studies, maintaining mean arterial pressure (MAP) within the range of 50-65 mmHg is considered permissive hypotension. MAP values below 60 mmHg have been associated with increased risk of cardiac and renal complications. However, in otherwise healthy patients, such episodes are frequently tolerated without clinically apparent renal dysfunction. The kidneys have a strong compensatory reserve capacity, and early tubular injury may not be detected by conventional renal function tests such as serum creatinine. Therefore, the use of more sensitive biomarkers is necessary to detect potential subclinical injury. In this prospective observational study, plasma NGAL and cystatin C levels will be measured from routine preoperative and postoperative (12-24 hours) blood samples obtained from adult patients undergoing rhinologic procedures. A ≥25% increase in these biomarkers from baseline will be considered indicative of subclinical acute kidney injury. Additionally, intraoperative hemodynamic data will be monitored, and the duration of MAP \<60 mmHg and MAP \<65 mmHg will be recorded. At the end of the procedure, surgical field conditions will be evaluated using the Boezaart Surgical Field Score. The relationship between these parameters and biomarker changes will be analyzed. The goal of this study is to determine whether early, clinically silent renal injury may occur during permissive hypotension and to provide insight into its potential implications for future renal function. All interventions and blood samplings are part of routine care, and no additional procedures will be performed for research purposes.

Conditions

Acute Kidney Injury; Hypotension

Keywords

Permissive Hypotension; Subclinical Kidney Injury; NGAL; Cystatin C; Rhinologic Surgery; Surgical Field Visibility; Boezaart Score

Outcome Measures

Primary Outcomes (1)

• Change in plasma NGAL and cystatin C concentrations indicating subclinical kidney injury

  Plasma neutrophil gelatinase-associated lipocalin (NGAL) concentration (ng/mL) measured by ELISA assay and plasma cystatin C concentration (mg/L) measured by automated nephelometric assay will be assessed preoperatively and at postoperative 12-24 hours. A relative increase of ≥25% from baseline in either biomarker will be used to define subclinical renal injury.

  Preoperative baseline to postoperative 12-24 hours

Secondary Outcomes (4)

• Duration of mean arterial pressure below 60 mmHg during anesthesia

  Intraoperative period

• Duration of mean arterial pressure below 65 mmHg during anesthesia

  Intraoperative period

• Correlation between intraoperative hypotension duration and renal biomarker changes

  Intraoperative period to postoperative 12-24 hours

• Correlation between surgical field quality and intraoperative hypotension

  End of surgery

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adult patients aged 18-65 years undergoing elective rhinologic surgery under controlled hypotension anesthesia at a single tertiary care center will be enrolled. The study population consists of otherwise healthy individuals (ASA I-II) without known kidney disease and without major comorbidities that could independently affect renal function.

You may qualify if:

• Adults aged 18-65 years
• Scheduled for elective rhinologic surgery (rhinoplasty, septoplasty, or functional endoscopic sinus surgery)
• ASA physical status I-II
• Able to provide written informed consent
• Undergoing controlled hypotension anesthesia as part of routine clinical management

You may not qualify if:

• Known chronic kidney disease (baseline creatinine above normal range or documented CKD)
• Uncontrolled hypertension or uncontrolled diabetes mellitus
• Contraindications to controlled hypotensive anesthesia
• Pregnant or breastfeeding women
• History of major cardiovascular disease affecting renal perfusion (e.g., severe heart failure)
• Use of nephrotoxic medications preoperatively that may interfere with renal biomarker interpretation
• Perioperative complications requiring deviation from routine anesthetic management (e.g., major bleeding or hemodynamic instability)

Sponsors & Collaborators

• Gazi University: lead

Study Sites (1)

Gazi University Faculty of Medicine

Ankara, Yenimahalle, 06500, Turkey (Türkiye)

Location

Related Publications (5)

• Salmasi V, Maheshwari K, Yang D, Mascha EJ, Singh A, Sessler DI, Kurz A. Relationship between Intraoperative Hypotension, Defined by Either Reduction from Baseline or Absolute Thresholds, and Acute Kidney and Myocardial Injury after Noncardiac Surgery: A Retrospective Cohort Analysis. Anesthesiology. 2017 Jan;126(1):47-65. doi: 10.1097/ALN.0000000000001432.

  PMID: 27792044 BACKGROUND

• Petrova I, Alexandrov A, Vladimirov G, Mateev H, Bogov I, Paskaleva I, Gotcheva N. NGAL as Biomarker of Clinical and Subclinical Damage of Kidney Function after Coronary Angiography. Diagnostics (Basel). 2023 Mar 20;13(6):1180. doi: 10.3390/diagnostics13061180.

  PMID: 36980488 BACKGROUND

• Sessler DI, Bloomstone JA, Aronson S, Berry C, Gan TJ, Kellum JA, Plumb J, Mythen MG, Grocott MPW, Edwards MR, Miller TE; Perioperative Quality Initiative-3 workgroup; POQI chairs; Miller TE, Mythen MG, Grocott MP, Edwards MR; Physiology group; Preoperative blood pressure group; Intraoperative blood pressure group; Postoperative blood pressure group. Perioperative Quality Initiative consensus statement on intraoperative blood pressure, risk and outcomes for elective surgery. Br J Anaesth. 2019 May;122(5):563-574. doi: 10.1016/j.bja.2019.01.013. Epub 2019 Feb 27.

  PMID: 30916004 BACKGROUND

• Ostermann M, Legrand M, Meersch M, Srisawat N, Zarbock A, Kellum JA. Biomarkers in acute kidney injury. Ann Intensive Care. 2024 Sep 15;14(1):145. doi: 10.1186/s13613-024-01360-9.

  PMID: 39279017 BACKGROUND

• Khetpal S, Elias A, Alford J, et al. Anesthesia for rhinoplasty: a summary of clinical considerations, therapeutic modalities, outcomes, and future directions. JCA Adv. 2024;1:100040. doi:10.1016/j.jcadva.2024.100040.

  BACKGROUND

Biospecimen

Retention: SAMPLES WITHOUT DNA

Routine perioperative blood samples will be collected, and in addition to standard biochemical tests, NGAL and cystatin C levels will be measured. Cystatin C will be analyzed daily as part of routine clinical workflow, whereas plasma samples for NGAL measurement will be stored at -20°C and analyzed later using a validated ELISA method. No genetic analyses will be performed.

MeSH Terms

Conditions

Acute Kidney Injury; Hypotension

Condition Hierarchy (Ancestors)

Renal Insufficiency; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Vascular Diseases; Cardiovascular Diseases

Study Officials

• Hasan K Pampal, M.D.

  Gazi University Faculty of Medicine, Department of Anesthesiology and Reanimation

  STUDY DIRECTOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 2 Days
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: M.D.

Study Record Dates

• First Submitted: December 25, 2025
• First Posted: January 9, 2026
• Study Start: March 1, 2025
• Primary Completion: May 30, 2025
• Study Completion: July 30, 2025
• Last Updated: February 4, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)