ULTRASOUND ASSESSMENT OF GASTRİC VOLUME IN PREGNANT WOMEN UNDERGOİNG ELECTİVE CESAREAN SECTİON, WITH AND WITHOUT GESTATİONAL DIABETES MELLITUS

DURING PREGNANCY, GASTRIC EMPTYING CAN BE AFFECTED AND THE RISK OF ASPIRATION MAY INCREASE DUE TO PHYSIOLOGICAL HORMONAL CHANGES, ELEVATED INTRA-ABDOMINAL PRESSURE, AND SLOWED GASTROINTESTINAL MOTILITY. ALTHOUGH CESAREAN SECTIONS ARE OFTEN PERFORMED UNDER REGIONAL ANESTHESIA, THEY REMAIN CLINICALLY RELEVANT IN TERMS OF ASPIRATION RISK DUE TO THE POTENTIAL NEED FOR GENERAL ANESTHESIA (1, 2).

GESTATIONAL DIABETES MELLITUS (GDM) IS A COMMON METABOLIC DISORDER DURING PREGNANCY THAT MAY AFFECT AUTONOMIC NERVOUS SYSTEM FUNCTION AND GASTROINTESTINAL MOTILITY. WHILE DIABETIC GASTROPARESIS IS WELL CHARACTERIZED IN PATIENTS WITH TYPE 1 AND TYPE 2 DIABETES MELLITUS, DATA REGARDING THE EFFECT OF GDM ON GASTRIC EMPTYING DYNAMICS REMAIN LIMITED (2, 3).

IN RECENT YEARS, GASTRIC ULTRASONOGRAPHY HAS BECOME AN INCREASINGLY UTILIZED METHOD IN ANESTHESIA PRACTICE, ENABLING THE NON-INVASIVE ASSESSMENT OF GASTRIC CONTENTS AND VOLUME. THIS TECHNIQUE ALLOWS FOR THE OBJECTIVE EVALUATION OF GASTRIC CONTENTS REGARDLESS OF STANDARD FASTING INTERVALS AND FACILITATES AN INDIVIDUALIZED ASSESSMENT OF ASPIRATION RISK (3).

THE RATIONALE FOR THIS STUDY IS TO DETERMINE THE EFFECT OF GDM ON PREOPERATIVE GASTRIC VOLUME BY COMPARING GASTRIC VOLUMES MEASURED VIA GASTRIC ULTRASOUND IN PREGNANT WOMEN SCHEDULED FOR ELECTIVE CESAREAN SECTIONS, WITH AND WITHOUT A DIAGNOSIS OF GDM, THEREBY CONTRIBUTING TO PERIOPERATIVE ANESTHETIC RISK ASSESSMENT.

THIS STUDY HAS BEEN DESIGNED AS A PROSPECTIVE, OBSERVATIONAL, COMPARATIVE, AND PARALLEL-GROUP CLINICAL TRIAL

**PATIENT SELECTION:** PREGNANT WOMEN TO BE INCLUDED IN THE STUDY WILL BE SELECTED VIA A CONSECUTIVE SAMPLING METHOD (BASED ON THE ORDER OF ARRIVAL) FROM AMONG PATIENTS SCHEDULED FOR ELECTIVE CESAREAN SECTION AT GAZIANTEP CITY HOSPITAL BY THE DEPARTMENT OF ANESTHESIOLOGY AND REANIMATION AND THE DEPARTMENT OF OBSTETRICS AND GYNECOLOGY, WHO MEET THE INCLUSION AND EXCLUSION CRITERIA.

PATIENTS WILL BE GROUPED SOLELY BASED ON THE PRESENCE OR ABSENCE OF GESTATIONAL DIABETES MELLITUS (GDM). NO SELECTIVE SAMPLING WILL BE PERFORMED REGARDING AGE, BODY MASS INDEX, OBSTETRIC CHARACTERISTICS, SURGICAL TEAM, OR FETAL CHARACTERISTICS.

PATIENTS WILL BE DIVIDED INTO TWO GROUPS:

• GROUP 1:** PREGNANT WOMEN DIAGNOSED WITH GESTATIONAL DIABETES MELLITUS (GDM)
• GROUP 2:** PREGNANT WOMEN WITHOUT A DIAGNOSIS OF GESTATIONAL DIABETES MELLITUS (GDM) DATA REGARDING THE PATIENTS INCLUDED IN THE STUDY WILL BE OBTAINED FROM PATIENT CHARTS, HOSPITAL INFORMATION MANAGEMENT SYSTEM (HIMS) RECORDS, AND ULTRASONOGRAPHIC MEASUREMENTS PERFORMED BY THE RESEARCHER DURING THE PREOPERATIVE PERIOD. ALL DATA WILL BE PROSPECTIVELY RECORDED ON A STANDARDIZED CASE REPORT FORM.

**DATA TO BE COLLECTED:**

• DEMOGRAPHIC DATA:** AGE, BODY MASS INDEX (BMI), GESTATIONAL AGE
• CLINICAL DATA:** PRESENCE OF GESTATIONAL DIABETES MELLITUS (GDM), ASA PHYSICAL STATUS CLASSIFICATION, FASTING DURATIONS (SEPARATELY FOR SOLIDS AND LIQUIDS, IN HOURS), AND COMORBIDITIES
• ULTRASONOGRAPHIC MEASUREMENTS:** ANTEROPOSTERIOR (AP) DIAMETER OF THE GASTRIC ANTRUM, CRANIOCAUDAL (CC) DIAMETER, ANTRAL CROSS-SECTIONAL AREA (CSA), AND ESTIMATED GASTRIC VOLUME (ML) DURING THE PREOPERATIVE PERIOD, THE GASTRIC ANTRUM WILL BE ASSESSED USING AN ULTRASOUND DEVICE BY AN EXPERIENCED ANESTHESIA RESIDENT OR ANESTHESIOLOGIST. THE PATIENT WILL BE EXAMINED IN BOTH THE SUPINE AND RIGHT LATERAL DECUBITUS POSITIONS. THE ANTEROPOSTERIOR AND CRANIOCAUDAL DIAMETERS OF THE GASTRIC ANTRUM WILL BE MEASURED, AND THE ANTRAL CROSS-SECTIONAL AREA WILL BE CALCULATED.

FOR PATIENTS ENROLLED IN THE STUDY, TRANSABDOMINAL GASTRIC ULTRASOUND WILL BE PERFORMED TWICE, IN TWO DIFFERENT POSITIONS, DURING THE PREOPERATIVE PERIOD. NO INTERVENTIONS WILL BE MADE REGARDING THE PLANNED MEDICAL TREATMENT OR SURGICAL PROCEDURE. ONLY NON-INVASIVE ROUTINE MEDICAL MEASUREMENTS WILL BE PERFORMED TO ASSESS THE PATIENT'S CURRENT CLINICAL STATUS.

Inclusion criteria

• PREGNANT WOMEN AGED 18-65 YEARS WITH A SINGLETON PREGNANCY,
• GESTATIONAL AGE OF 36 WEEKS OR MORE,
• ASA PHYSICAL STATUS CLASSIFICATION OF II-III WILL BE INCLUDED IN THE STUDY.
• PARTICIPANTS WILL BE SELECTED FROM PATIENTS SCHEDULED FOR ELECTIVE CESAREAN SECTION WHO HAVE BEEN INFORMED ABOUT THE OBJECTIVES AND PROCEDURES OF THE STUDY AND WHO SIGN THE INFORMED CONSENT FORM.

Exclusion criteria

• EMERGENCY CESAREAN SECTION CASES.
• MULTIPLE PREGNANCIES.
• PATIENTS WITH GASTROINTESTINAL DISEASES, INCLUDING SYMPTOMATIC OR TREATMENT-REQUIRING GASTROESOPHAGEAL REFLUX DISEASE, PEPTIC ULCER DISEASE, ACTIVE SYMPTOMATIC GASTRITIS, A HISTORY OF DIABETIC GASTROPARESIS, INFLAMMATORY BOWEL DISEASES (CROHN'S DISEASE OR ULCERATIVE COLITIS), OR A HISTORY OF GASTROINTESTINAL SURGERY, PARTICULARLY GASTRIC OR ESOPHAGEAL SURGERY.
• PATIENTS WITH SYSTEMIC DISEASES THAT MAY AFFECT GASTRIC MOTILITY, INCLUDING TYPE 1 OR TYPE 2 DIABETES MELLITUS (EXCLUDING GDM), UNCONTROLLED HYPOTHYROIDISM OR HYPERTHYROIDISM, NEUROLOGICAL DISEASES (E.G., PARKINSON'S DISEASE, MULTIPLE SCLEROSIS, OR AUTONOMIC NEUROPATHY), OR CONNECTIVE TISSUE DISEASES (E.G., SCLERODERMA).
• PATIENTS WITH SEVERE SYSTEMIC COMORBIDITIES, INCLUDING ASA PHYSICAL STATUS CLASSIFICATION IV OR HIGHER, ADVANCED CARDIAC DISEASE (E.G., NYHA CLASS III-IV HEART FAILURE), ADVANCED RESPIRATORY SYSTEM DISEASE (E.G., SEVERE CHRONIC OBSTRUCTIVE PULMONARY DISEASE OR RESTRICTIVE LUNG DISEASE), RENAL FAILURE (STAGE 4-5 CHRONIC KIDNEY DISEASE), OR HEPATIC FAILURE (CHILD-PUGH CLASS B-C).
• PATIENTS USING MEDICATIONS THAT MAY AFFECT GASTRIC MOTILITY, INCLUDING PROKINETIC AGENTS, ANTICHOLINERGIC DRUGS, OR OPIOIDS.
• PATIENTS WHO REFUSE TO PARTICIPATE IN THE STUDY OR DO NOT SIGN THE INFORMED CONSENT FORM.