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Three Part Question

In [blunt abdominal trauma patients] is [computed tomography scanning better than diagnostic peritoneal lavage] at [identifying intraabdominal injury]?

Clinical Scenario

A 65 year old patient with Alzheimer's disease presents to the accident and emergency department following a fall. Abdominal injury is suspected. The patient's BP systolic is 96mmHg, pulse rate 110. Is CT scanning more efficacious at diagnosing abdominal injury that diagnostic peritoneal lavage (DPL)?

Search Strategy

OVID Medline, EMBASE and CINAHL interfaces
{[exp Wounds, Nonpenetrating/ or exp Abdominal Injuries/ or exp Multiple Trauma/ or exp Accidents, Traffic/ orblunt.mp. or crush.mp.] AND [exp Tomography, Spiral Computed/ or exp Tomography, X-Ray Computed/ or CT.mp.] AND [Peritoneal lavage.mp. or exp Peritoneal Lavage or DPL.mp or exp Hemoperitoneum/ or Haemoperitoneum.mp. or Diagnostic peritoneal lavage.mp.]}

Search Outcome

OVID Medline -392 papers found of which 6 were relevant to the three part question.
EMBASE - 74 papers found 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
Gonzalez RP. Ickler J. Gachassin P 2001 USA	252 patients assessed for blunt abdominal trauma via CT alome (125 patients) and DPL +/- CT (127 patients). Results were evaluated in comparison to laparotomy findings	PRCT	False negative scan (CT alone)	2/125	No statistics includeed
			False negative scan (DPL and CT)	0/127
			Economic values	CT arm - $1611 and DPL/CT arm $650
Meyer DM. Thal ER. Weigelt JA. Redman HC. 1989 UK	301 haemodynamically stable patients who underwent both CT and DPL. Results of CT/DPL were compared to findings on susbsequent laparotomy.	Prospective cohort study.	Negative CT scan	194/301 (71.6%)
			Positive CT Scan	51/301 (27.1%)
			False negative CT scan vs positive DPL with postive Laparotomy	19/194 (9.8%)
			False negative DPL	3/194 (1.5%)
Mele TS. Stewart K. Marokus B. O'Keefe GE 1999 Canada	167 patients split into two groups - one group that recevies DPL +/- CT (71 patients) and one group that only receives CT (96 patients). Results of CT/DPL were compared to laparotomy findings.	Prospective cohort study. Evidence level 2++	Missed injuries	7/96 in the CT only group. 0/71 in the DPL +/- CT group
			Time to diagnosis	Average 2.5 hours CT only group. Average 41 minutes in DPL +/- CT group
Blow O. Bassam D. Butler K. Cephas GA. Brady W. Young JS 1998 USA	1,182 patients admitted during 1994 to an accident and emergency department, 589 of which underwent CT scan, 593 of which underwent DPL +/- CT scan. Results were compared to findings on laparotomy	Prospective cohort study. Evidence level 2++	Sensitivity	CT 100% DPL 100%	None
			Specificity	CT 99% DPL 98%
			Positive predictive value	CT 90% DPL 94%
			Negative predicitive value	CT 100% DPL 100%
			Accuracy	CT 99.2% DPL 98.4%
			Cost Analysis	CT $1009 DPL $247
			Time to Laparotomy (minutes)	CT 231 +/- 149 DPL 61 +/- 51
Bell C. Coleridge ST 1992 USA	A total of 545 patients from 6 different prospective cohort studies, all of which underwent either CT or DPL in the evaluation of suspected blunt abdominal injury. Results were compared to laparotomy findings	Systematic review - evidence level 2+	Averaged sensitvity (DPL)	96%	5/6 studies had very small sample sizes. No statistical analysis given.
			Averaged sensitivity (CT)	44%
			Averaged specificity (DPL)	93%
			Avergaed specificity (CT)	96%
Davis JW. Hoyt DB. Mackersie RC. McArdle MS 1990 Dec USA	A review of 2,809 DPLs and 1,331 CT scans performed over a three year period in patients investigated for blunt abdominal trauma. Results of tests compared with laparotomy rates and findings on laparotomy.	Retrospective cohort. Evidence level 2++	False positive result	DPL (0.1%) CT (0.2%)	Retrospective study No statistics analysis performed.
			False negative result	DPL (0.3%) CT (1.8%)
			Complication rate (including technical errors and delays in treatment implementation)	DPL (0.9%) CT (3.4%)

Comment(s)

Independantly, DPL results in a high rate on non-theraputic laparotomies. While it has the advantages of rapidity and that fact that it is more cost effective, it cannot accurately diagnose retroperitoneal injury. Similarly, CT scans have been shown to produce more false positive and negative results when performed as the only diagnostic modality. Therefore, many studies advocate the use of the two methods in conjunction with one another.

Clinical Bottom Line

DPL may be used alone in haemodynamically unstable patients, those with concomitant head or chest injuries and those with open fractures. CT should be used in the inital evaluation of haemodynamically stable patients.

Level of Evidence

Level 2 - Studies considered were neither 1 or 3.

References

1. Gonzalez RP. Ickler J. Gachassin P Complementary roles of diagnostic peritoneal lavage and computed tomography in the evaluation of blunt abdominal trauma Journal of Trauma-Injury Infection & Critical Care. Vol. 51(6) 1128-1136
2. Meyer DM. Thal ER. Weigelt JA. Redman HC. Evaluation of computed tomography and diagnostic peritoneal lavage in blunt abdominal trauma. Journal of Trauma-Injury Infection & Critical Care 29 (8) 1168-1172 (1989)
3. Mele TS. Stewart K. Marokus B. O'Keefe GE Evaluation of a diagnostic protocol using screening diagnostic peritoneal lavage with selective use of abdominal computed tomography in blunt abdominal trauma Journal of Trauma-Injury Infection & Critical Care. 46(5) 1999 847-52
4. Blow O. Bassam D. Butler K. Cephas GA. Brady W. Young JS Speed and efficiency in the resuscitation of blunt trauma patients with multiple injuries: the advantage of diagnostic peritoneal lavage over abdominal computerized tomography Journal of Trauma-Injury Infection & Critical Care. 44(2) 287-90, 1998 Feb
5. Bell C. Coleridge ST A comparison of diagnostic peritoneal lavage and computed tomography (CT scan) in evaluation of the hemodynamically stable patient with blunt abdominal trauma Journal of Emergency Medicine. 10(3) 275-80, 1992 May-Jun
6. Davis, J W. Hoyt, D B. Mackersie, R C. McArdle, M S Complications in evaluating abdominal trauma: diagnostic peritoneal lavage versus computerized axial tomography Journal of Trauma-Injury Infection & Critical Care. 30(12) 1506-9, 1990 Dec