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Three Part Question

In [blunt abdominal trauma patients] are [CT scans using oral contrast better than conventional CT scans] at [identifying intra-abdominal injury]?

Clinical Scenario

Following an RTA, the female driver of one of the vehicles is stretchered into the accident and emergency department, complaining of epigastric pain. She displays the "seatbelt sign", her BP is >100mmHg and her pulse rate is 95bpm. The decision is made to CT scan her abdomen, and the use of oral contrast solution is debated between two registrars in the resuscitation area. One advocates its use, arguing that extravastion will be more easily spotted. The other suggests that an unacceptable delay will be cause by its administration. Should oral contrast be used in this situation?

Search Strategy

OVID Medline, EMBASE and CINAHL interfaces
{[exp Multiple Trauma OR exp Child OR exp Middle Aged OR exp Accidents, Traffic OR exp Adult OR exp Appendicitis OR exp Wounds, Nonpenetrating OR exp Tomography, X-Ray Computed OR exp Abdominal Injuries OR exp Adolescent OR exp Pancreas OR exp Hospitalization OR exp Pancreatic Neoplasms OR exp Abdomen OR exp Liver Neoplasms OR exp Abdomen, Acute OR exp Gastrointestinal Diseases] AND [exp Image Enhancement OR exp Tomography, X-Ray Computed OR Tomography, Spiral Computed OR exp Contrast Media]

Search Outcome

OVID Medline produced a total of 94 papers, of which 3 were relative to the three part question
EMBASE produced a total of 68 papers, of which none were relevant to the three part question

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Gareth Lock 17/07/06 UK	101 children who underwent CT between 1993 and 1997. Median age 9.5 (range 1.5-16.5 years)	Retrospective cohort study. Evidence level 2+	True positive CT scan (no contrast)	17/44 - 39%	Only four patients diagnosed with intestinal injury to assess the efficacy of oral contrast - small sample size. No statistical tests carried out. Retrospective data
			False positive CT scan (no contrast)	0/44
			True negative CT scan (no contrast)	26/44 - 59%
			False negative scan (no contrast)	1/44 - 2.2%
			True positive CT scan (contrast)	16/60 - 28%
			False positive CT scan (contrast)	1/60 - 1.7%
			True negative CT scan (contrast)	42/60 - 70%
			False negative scan (contrast)	1/60 - 1.7%
Gareth Lock 17/07/06 UK	199 patients receiving oral contrast, 195 patients not receving oral contrast for blunt abdominal trauma. All patients over 18 years of age.	RCT Evidence level 1+	Oral contrast group sensitivity, specificity for solid organ injury	Sensitivity 84.2% Specificity 94%	Non-blinded control trial
			Oral contrast group sensitivity, specificity for intestinal perforation	Sensitivity 86% Specificity 100%
			Non-oral contrast group sensitivity, specificity for solid organ injury	Sensitivity 88.9% Specificity 51.7%
			Non-oral contrast group sensitivity, specificity for intestinal perforation	Sensitivity 100% Specificity 100%
Gareth Lock 17/07/061 UK	248 patients having CT scan between June 1988 and November 1993, of which 70 CT cases were reviewed.	Retrospective cohort study 2+	Intestinal injury	0/21 intestinal injuries found on laparotomy were found on contrast CT scanning.	Retrospective Only 70 of 124 CT scans were evaluated. No control group. Attribution of vomiting to oral contrast may be erroneous.
			Pancreatic injury	3/6 pancreatic injuries found on laparotomy were missed on contrast CT scanning
			Vomiting	23% patients vomited - attributed to oral contrast use - one documented case of aspiration
			Liver and Spleen injury	100% accuracy

Comment(s)

More large multicentre prospective control trials are required to assess the efficacy of contrast CT scanning in the evaluation of blunt abdominal trauma. Many studies had relatively small sample sizes.

Clinical Bottom Line

The use of oral contrast in most cases of blunt abdominal trauma is unwarranted, with delayed time to diagnosis, increased chance of aspriation. It should only be used if intestinal injury is suspected, and even then only with adequate airway management

References

1. Shankar, K R. Lloyd, D A. Kitteringham, L. Carty, H M Oral contrast with computed tomography in the evaluation of blunt abdominal trauma in children British Journal of Surgery 86(8) 1073-7 1999 Aug
2. Stafford RE. McGonigal MD. Weigelt JA. Johnson TJ Oral contrast solution and computed tomography for blunt abdominal trauma: a randomized study Archives of Surgery. 134(6) 622-7, 1999 Jun
3. Tseng B.D. et al Effect of oral contrast administration for abdominal computer tomography in the evaluation of acunt blunt trauma Annals of Emergency Medicine 30(1) 7-13 Jul 1997