title: Interrater reliability of qualitative ultrasound assessment of gastric content in the third trimester of pregnancy.
abstract: BACKGROUND
  Pulmonary aspiration of gastric contents in pregnant women undergoing general anaesthesia is one of the most feared complications in obstetric anaesthesia. Bedside gastric ultrasonography is a feasible imaging tool to assess the gastric content. The purpose of this study was to investigate the reliability of qualitative bedside assessment of the gastric content performed by anaesthesiologists on third trimester pregnant women.
  
  
  METHODS
  Pregnant women (≥32 weeks gestational age) were randomized to undergo ultrasound (US) assessments of their stomach in a fasting state (>8 h), or after ingestion of clear fluids only, or solid food. Three anaesthesiologists trained in gastric ultrasonography performed the assessments using a low-frequency curved-array US transducer (5-2 MHz). Primary outcome of the study was the consistency of raters in diagnosing the correct status of the gastric content, which was used to determine the interrater reliability among the three anaesthesiologists. Secondary outcomes were overall proportion of correct and incorrect diagnoses and the specific proportions of correct diagnosis across the three gastric content groups.
  
  
  RESULTS
  We analysed 32 pregnant women. The interrater reliability displayed a kappa statistic of 0.74 (bias corrected 95% CI: 0.68-0.84). The overall proportion of correct diagnosis was 87.5% (84 of 96). The odds of correct diagnosis for 'solid contents' were 16.7 times the odds for 'empty', and 14.3 times for 'clear fluid'.
  
  
  CONCLUSIONS
  Our results show the consistency of the qualitative US assessment of gastric contents of pregnant women in the third trimester by anaesthesiologists. A kappa of 0.74 suggests substantial agreement in terms of interrater reliability for this diagnostic measurement.
  
  
  BACKGROUND
  ClinicalTrials.gov identifier: NCT01564030.
authors: Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Room 19-104, Toronto, ON, Canada M5G 1X5 carzola@mtsinai.on.ca.
authors: C
authors: C
authors: Arzola
authors: Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Room 19-104, Toronto, ON, Canada M5G 1X5 Department of Anesthesia, Hospital Universitario San Ignacio, Pontificia Universidad Javeriana, Carrera 7 No. 40-62, Bogota, Colombia.
authors: J
authors: J
authors: Cubillos
authors: Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, McLaughlin Pavilion 2-405, 399 Bathurst St, Toronto, ON, Canada M5-T 2S8.
authors: A
authors: A
authors: Perlas
authors: Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Room 19-104, Toronto, ON, Canada M5G 1X5.
authors: K
authors: K
authors: Downey
authors: Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Room 19-104, Toronto, ON, Canada M5G 1X5.
authors: J C A
authors: JC
authors: Carvalho
mesh_terms: D000328:Adult; D000773:Anesthesia, Obstetrical / Q000009:adverse effects / Q000379:methods; D015331:Cohort Studies; D004326:Drinking / Q000502:physiology; D004435:Eating / Q000502:physiology; D005215:Fasting / Q000502:physiology; D005260:Female; D005766:Gastrointestinal Contents; D006801:Humans; D015588:Observer Variation; D011015:Pneumonia, Aspiration / Q000209:etiology / Q000517:prevention & control; D019095:Point-of-Care Systems; D011247:Pregnancy; D011248:Pregnancy Complications / Q000517:prevention & control; D011263:Pregnancy Trimester, Third / Q000502:physiology*; D011706:Pyloric Antrum / Q000000981:diagnostic imaging; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D013270:Stomach / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D055815:Young Adult
keywords: complications, aspiration; complications, regurgitation; equipment, ultrasound machines; gastrointestinal tract, preoperative aspiration; pregnancy