Gastric Ultrasound in Diabetic and Non-Diabetic Pregnant Women
Condition: Gastric Ultrasonography; Gastric Volume; Pulmonary Aspiration; Diabetic Pregnancy; Fasting
MeSH terms: Pregnancy in Diabetics
Study type: Observational

Summary: 
      Perioperative aspiration is particularly concerning in pregnant women due to anatomical
      changes. To mitigate this risk, pre-anesthetic fasting is recommended, with varying
      guidelines. Gastric ultrasound can non-invasively assess stomach contents, and mathematical
      models help estimate stomach volumes using the gastric antral cross-sectional area (CSA).

      This study aims to compare CSA and estimated gastric volumes through ultrasound in fasting
      diabetic and non-diabetic pregnant women scheduled for cesarean section, as diabetes may
      affect stomach fullness. Additionally, it will investigate the relation between demographic
      and clinical variables and CSA values.

      This research can shed light on diabetes' influence on aspiration risk in pregnancy and
      evaluate fasting guidelines, underscoring the significance of gastric ultrasound.
    

Detailed description: 
      Perioperative aspiration of stomach contents is rare but is a serious complication of
      anesthesia and is associated with high morbidity and mortality. In pregnant women, it is
      known that the risk of aspiration is high even after standard preoperative fasting, due to
      anatomical changes such as the displacement of the stomach by pressure from the uterus, the
      sliding of the lower segment of the esophagus into the thorax, the relaxation of the lower
      esophageal sphincter, and the smooth muscle relaxation induced by progesterone.

      In cases where regional anesthesia is contraindicated, various measures, including prokinetic
      and antacid medications, rapid-sequence anesthetic induction, and tracheal intubation, are
      used to reduce the risk and severity of pulmonary aspiration. However, the most commonly used
      measure is pre-anesthetic fasting in the patient. The European Society of Anaesthesiology
      (ESA) recommends fasting for ≥2 hours after clear liquids and 6 hours after light meals
      before elective surgery, including in pregnant patients.

      The American Society of Anesthesiologists (ASA), on the other hand, recommends longer fasting
      times in pregnant patients without specifying the duration.

      Aspiration risk in pregnant women is multifactorial. The type and volume of stomach contents,
      which are the main risk factors for aspiration, can be easily evaluated preoperatively with
      gastric ultrasonography. The presence of solids or thick liquids indicates a high risk of
      aspiration, independent of stomach volume.

      However, in the presence of clear liquid, the risk of aspiration is generally linked to the
      volume of liquid in the stomach. The clear stomach volume limits that increase the risk of
      aspiration are controversial.

      Some studies have shown that fasted patients generally have a gastric residual volume of up
      to 1.5 mL kg-1, and this value is used to determine the stomach at high risk for aspiration.

      Gastric ultrasound assessment is an easy method that can be applied non-invasively at the
      bedside for evaluating gastric contents before anesthesia induction in the obstetric
      population. By measuring the gastric antral cross-sectional area (CSA), it may be possible to
      identify patients at risk for pulmonary aspiration with an estimate of stomach volume.
      Studies have shown the presence of a good linear correlation between antral CSA and stomach
      volume, not only in non-pregnant individuals but also in pregnant individuals.

      Additionally, antral CSA measurement can indirectly differentiate small gastric volumes,
      consistent with initial gastric secretions, ≤1.5 mL kg-1, from larger volumes that may be
      associated with increased pulmonary aspiration risk.

      Perlas et al. have developed a simple mathematical model based on the patient's age and
      antral CSA value measured in the right lateral position to calculate the volume of stomach
      fluid in non-pregnant adults and children.

      Recently, two different mathematical models have been defined by Arzola et al.and
      Roukhomovsky et al. to estimate stomach volumes in pregnant patients. In this study, the
      investigators will use the mathematical formula developed by Roukhomovsky et al., as this
      model evaluates the presence of any stomach content, liquid or solid, rather than the volume
      of fluid swallowed as standard, with MR. Additionally, the model of Perlas et al., which is
      widely used in clinical practice and has been verified by studies, will be used.

      It is accepted that there is gastroparesis in 9.9% - 76% of diabetic patients. Garg et al. in
      their prospective case-control study including 103 non-pregnant patients found that diabetic
      patients had higher gastric antral CSA and gastric volumes than non-diabetic patients. Sharma
      et al. have also shown that fasting for more than 6-10 hours does not guarantee an empty
      stomach and patients with comorbid diseases such as diabetes mellitus (DM), obesity are prone
      to having risky stomach contents. In DM patients, a significant increase in CSA in both
      supine and right lateral decubitus positions was detected compared to non-DM patients.
      Additionally, in the same study, it was found that as BMI increased from 25 to 35, there was
      a steady increase in CSA in both supine and right lateral decubitus positions. However, these
      studies were conducted in non-pregnant patients and the investigators did not come across
      similar studies conducted with diabetic pregnant women in the literature.

      Recently, gastric ultrasound scanning before anesthesia in cases where the fasting state is
      unclear or unknown in the pregnant patient population, which is known to be more risky in
      terms of pulmonary aspiration, is recommended although not yet widespread in practical use.
      The effect of diabetes on stomach fullness is still controversial. There are many studies on
      gastric ultrasound evaluation in pregnant women, but the investigators have not come across a
      study comparing diabetic pregnant women with non-diabetics. This study was planned based on
      the idea that the presence of diabetes in pregnant women could further increase the risk of
      pulmonary aspiration. The primary aim of this research is to compare the antral
      cross-sectional area (CSA) with gastric ultrasound and estimated gastric volumes calculated
      with 2 mathematical models in fasting diabetic and non-diabetic term pregnant women who will
      be taken for cesarean section.

      The secondary aim is to determine the relationship between demographic and clinical variables
      and gastric antral CSA values in fasting term pregnant women. the investigators believe that
      our study will contribute to the literature with its originality and results. Additionally,
      the investigators believe that our study will provide insight into the effectiveness of
      fasting guidelines in these patient groups and the necessity of gastric ultrasound scanning."
    

Intervention name(s): Gastric ultrasonography
Intervention type(s): Device
Intervention description(s): It seems like the text you provided is already in Turkish and it appears to be written in an academic style. If you want this text to be translated to English in an academic language, it would be:
Ultrasonographic evaluation of gastric contents in Diabetic and Non-Diabetic term pregnancies
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        It is planned to include 80 diabetic and non-diabetic patients aged 18-40 years, belonging
        to the ASA (American Society of Anesthesiologists) physical status class II-III, who are
        scheduled for elective cesarean surgery. Randomization will be carried out using a sealed
        envelope method. Two groups, each comprising 40 patients, will be formed and evaluated with
        preoperative gastric ultrasound.
      
Keywords: Diabetic Pregnant Women; Gastric ultrasonography; Gastric Contents; Gastric volume; Antral sectional area; Pregnant women