Renal Functions in Preeclamptic Pregnant Women Using Neutrophil Gelatinase-associated Lipocalin (NGAL) and Standard Renal Function Tests

Nihan Aydin Guzey

Status: Not yet enrolling

Conditions: Spinal Aneshtesia; Acute Kidney Failure; Spinal Anesthesia Induced Hypotension; Preeclampsia (PE); Anesthesia

Study type: Observational

Funder types: Other

Identifiers

NCT07015359

TABED 2/170/2024

Details and patient eligibility

About

Acute kidney injury (AKI) is a significant postoperative complication. Risk factors for AKI include impaired renal perfusion, decreased functional renal reserve, as well as advanced age, peripheral arterial disease, diabetes mellitus, renovascular disease and congestive heart failure. Mean arterial pressure (MAP) below 55-60 mmHg has been associated with postoperative AKI. Traditional diagnostic criteria for AKI include increased serum creatinine levels and oliguria. However, creatinine levels do not rise until more than half of renal function is lost. Serum and urine NGAL levels rise earlier-within 24-48 hours-making it a promising early biomarker.

In our study, hypotension is defined as systolic blood pressure <100 mmHg or a >30% decrease in MAP. Patients requiring ephedrine under these conditions will be evaluated as the hypotension group and compared with non-hypotensive patients in terms of NGAL, BUN (blood urea nitrogen), creatinine, and GFR (Glomerular Filtration Rate) values at baseline and at the 4th postoperative hour.

Full description

All patients were informed about the study in the preoperative period and written informed consent was obtained before the procedure. The following data were recorded: age, sex, weight, height, BMI (Body Mass Index), comorbidities, regular medications, ASA (American Society of Anesthesiologists) classification, gestational age, history of preeclampsia in previous pregnancies, hemodynamic values and laboratory results. After being admitted to the cesarean operating room, patients were monitored according to the ASA guidelines using standard monitoring methods (non-invasive arterial blood pressure measurements at 2-minute intervals, 3-lead ECG (Electrocardiogram) and pulse oximetry). A peripheral intravenous line was established via the dorsum of the hand and Ringer's lactate was infused at a rate of 10 mL/kg/h. All patients received oxygen via nasal cannula at a rate of 3-4 L/min.

Blood samples were collected from the patients before spinal anesthesia and at the 4th postoperative hour. The samples were centrifuged at 4000×g for 10 minutes in the biochemistry laboratory and then transferred into Eppendorf tubes and stored at -80°C in a deep freezer until the day of analysis. NGAL levels were measured using an ELISA (Enzyme-Linked ImmunoSorbent Assay) method with a commercial kit (USCN, China) at the Biochemistry Laboratory of Ankara Bilkent City Hospital. Each sample was measured in duplicate, and the mean values were used for evaluation. The intra-assay and inter-assay coefficients of variation (CV%) for the kit were determined to be <10% and <12%, respectively. At the 4th postoperative hour, blood samples were also analyzed for BUN, creatinine, and GFR levels, which were recorded accordingly.

Enrollment: 46 estimated patients

Sex: Female

Ages: 18 to 45 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients classified as ASA physical status II-III
• Pregnant women aged 18-45 years, diagnosed with preeclampsia and scheduled for elective cesarean section, will be included in the study.

Exclusion criteria

• Patients who are unable to read, understand, or sign the informed consent form
• Patients with a diagnosed renal disease
• Patients who do not wish to participate in the study
• Patients with ASA physical status greater than III
• Patients younger than 18 or older than 45 years
• Patients requiring sedation or undergoing general anesthesia
• Patients with cardiac instability
• Patients with known arrhythmias

Trial design

46 participants in 2 patient groups

CASE GROUP

Description:

During the operation, heart rate (HR) and peripheral oxygen saturation (SpO₂) were continuously monitored. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP) were measured and recorded every 2 minutes for the first 15 minutes, then every 5 minutes thereafter. Hypotension was defined as a ≥30% decrease in MAP from baseline or systolic blood pressure \<100 mmHg. Patients who developed hypotension within the first four measurements were included in the hypotension group. Patients who developed hypotension in later measurements were excluded from the study to avoid confusion with bleeding-related hypotension. A 5 mg bolus of ephedrine was administered to raise the MAP to 80% or more of the baseline level within 60 seconds. Surgical duration, amount of fluids administered, duration and number of hypotensive episodes, total dose of ephedrine, estimated blood loss, use of additional uterotonics or tranexamic acid, neonatal weight, and Apgar.

CONTROL GROUP

Description:

During the operation, the patient's heart rate (HR) and peripheral oxygen saturation (SpO₂) were continuously monitored. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP) were measured and recorded every 2 minutes for the first 15 minutes, and then every 5 minutes thereafter. Patients whose MAP did not decrease by 30% or more from the baseline value were considered the control group