Oral contrast for abdominal computed tomography in children: the effects on gastric fluid volume.
BACKGROUND
Oral enteric contrast medium (ECM) is frequently administered to achieve visualization of the gastrointestinal tract during abdominal evaluation with computed tomography (CT). Administering oral ECM less than 2 hours before sedation/anesthesia violates the nothing-by-mouth guidelines and in theory may increase the risk of aspiration pneumonia. In this study we measured the residual gastric fluid when using a protocol in which ECM is administered up to 1 hour before anesthesia/sedation. We hypothesized that patients receiving ECM 1 hour before anesthesia/sedation would have residual gastric fluid volume (GFV) >0.4 mL/kg.


METHODS
Anesthesia and radiology reports, CT images, and department incident reports were reviewed between January 2005 and June 2009 for all patients who required sedation/anesthesia for abdominal CT. For each patient, the volume of contrast or stomach fluid was calculated using a region of interest outlining the stomach portion containing high-attenuation fluid and low-attenuation of other gastric contents. Information obtained from anesthesia/sedation reports included demographic characteristics, presenting pathology, drugs used for anesthesia/sedation induction and maintenance, airway interventions, method for securing endotracheal tube, and complications related to ECM administration, including oxygen desaturation, vomiting, coughing, bronchospasm, laryngospasm, and aspiration.


RESULTS
We identified 365 patients (mean age = 32 months; range = 0.66 to 211.10 months) who received oral/IV contrast material before anesthesia/sedation for abdominal CT and 47 patients (mean age = 52 months; range = 0.63 to 215.84 months) who received only IV contrast material and followed the traditional fast. For those who received oral contrast, the mean contrast volume administered was 18.10 mL/kg (range = 1.5 to 82.76 mL/kg). The median GVF 1 hour after completing the oral contrast was significantly higher than that in patients who received only IV contrast (0.38 mL/kg vs. 0.15 mL/kg, P = 0.0049). GFV exceeded 0.4 mL/kg in 189 patients (178 of 365 [49%] in the oral contrast group vs. 11 of 47 [23%] in the IV contrast group) (χ(2) = 10.7874, P = 0.0010). Among those who received oral contrast, 207 patients had general anesthesia and 158 patients had deep sedation. Two cases of vomiting were reported in the general anesthesia group with no evidence of pulmonary aspiration identified.


CONCLUSIONS
For children receiving an abdominal CT, the residual GFV exceeded 0.4 mL/kg in 49% (178/365) of those who received oral ECM up to 1 hour before anesthesia/sedation in comparison with 23% (11/47) of those who received IV-only contrast.
Mahmoud
Mohamed
M
Department of Anesthesiology, Tehran University Children's Hospital Medical Center, Tehran, Iran. mohamed.mahmoud@cchmc.org
McAuliffe
John
J
Kim
Hwa-Young
HY
Mishra
Pragnyadipta
P
Salisbury
Shelia
S
Schnell
Beverly
B
Hirsch
Patricia
P
Arbabi
Shahriar
S
Donnelly
Lane F
LF
D000284:Administration, Oral; D000293:Adolescent; D000768:Anesthesia, General / Q000009:adverse effects; D018681:Anesthetics, General / Q000008:administration & dosage / Q000009:adverse effects; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media / Q000008:administration & dosage* / Q000009:adverse effects; D054810:Deep Sedation / Q000009:adverse effects; D004334:Drug Administration Schedule; D005215:Fasting; D005260:Female; D005750:Gastric Juice; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects; D007223:Infant; D007275:Injections, Intravenous; D007472:Iohexol / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D009820:Ohio; D011860:Radiography, Abdominal / Q000379:methods*; D053120:Respiratory Aspiration / Q000209:etiology; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids / Q000008:administration & dosage* / Q000009:adverse effects; D014839:Vomiting / Q000209:etiology
D018681:Anesthetics, General; D003287:Contrast Media; D006993:Hypnotics and Sedatives; D014283:Triiodobenzoic Acids; D007472:Iohexol; C054871:ioversol