Gastric Ultrasound for Airway Management in Emergency Patients

Emergency Surgical Patients

Adult emergency surgical patients (age >18 years) requiring airway management at the Emergency Operating Room of RSUPN Dr. Cipto Mangunkusumo (RSCM), who underwent preoperative gastric point-of-care ultrasound (PoCUS) to assess gastric content type and residual volume prior to anesthetic induction.

设备：Preoperative Gastric Point-of-Care Ultrasound (PoCUS)

Gastric antrum ultrasound performed using a low-frequency transducer (2-5 MHz; SonoSite M-Turbo or Lumify Philips) in the supine position before anesthetic induction. The antrum cross-sectional area (CSA) was measured during the relaxation phase between two peristaltic contractions, calculating cranio-caudal (CC) and antero-posterior (AP) diameters. Gastric residual volume (GRV) was calculated using the Perlas formula: GV = 27.0 + 14.6 × CSA - 1.28 × age (years). Gastric content was classified as empty, liquid, solid, or mixed. Aspiration risk was categorized as high (GRV ≥1.5 ml/kg or solid content) or low (GRV <1.5 ml/kg or empty).

其他名称：

• 胃超声检查
• Gastric USG
• Bedside Gastric Sonography

Association between aspiration risk based on gastric ultrasound findings and airway management technique selection

Proportion of patients in whom airway management technique (Rapid Sequence Intubation vs. non Rapid Sequence Intubation) was associated with aspiration risk category (high vs. low) determined by preoperative gastric Point-of-Care Ultrasound (PoCUS) findings. Aspiration risk classified as high if Gastric Residual Volume (GRV) ≥1.5 ml/kg or solid gastric content; low if GRV <1.5 ml/kg or empty stomach. Analyzed using chi-square test.

Change in Airway Management Plan After Gastric USG

Comparison of airway management plan (RSI vs. non-RSI) before and after disclosure of gastric USG findings to the treating anesthesiologist. Analyzed using McNemar's paired categorical test.

Gastric Residual Volume

Gastric residual volume calculated using the Perlas formula: GV = 27.0 + 14.6 × CSA - 1.28 × age (years), based on antrum cross-sectional area (CSA) measured from cranio-caudal (CC) and antero-posterior (AP) diameters. Reported as mean ± SD or median (range).

Gastric Content Type

Proportion of patients with each gastric content category: empty, liquid only, solid, or mixed (solid and liquid), as identified by gastric PoCUS.

Fasting Duration and Its Relationship to Gastric Residual Volume

Fasting duration categorized as <8 hours, 8-12 hours, or >12 hours since last solid food intake, and its relationship to gastric residual volume and aspiration risk classification on USG.

American Society of Anesthesiologists (ASA) Physical Status Classification as a factor in airway management decision

Proportion of patients in each American Society of Anesthesiologists (ASA) class (I, II, III, IV) and its association with airway management technique selection (RSI vs. non-RSI) after gastric USG, analyzed using chi-square test.

Trauma Severity Score (ISS) as a factor in airway management decision

Injury Severity Score (ISS) categorized as severe (ISS ≥15) or mild-moderate (ISS <15) and its association with airway management technique selection (RSI vs. non-RSI) after gastric USG, analyzed using chi-square test.

Glasgow Coma Scale (GCS) score as a factor in airway management decision

GCS score recorded at pre-induction assessment and its association with airway management technique selection (RSI vs. non-RSI) after gastric USG.

Presence of clinical risk factors (sepsis, shock, GERD/gastritis) as a factor in airway management decision

Proportion of patients with each clinical risk factor (sepsis, hemorrhagic shock, GERD/gastritis) and its association with airway management technique selection (RSI vs. non-RSI) after gastric USG, analyzed using chi-square or Fisher's exact test.