Session III - Combined Meeting with AAST

Influence of Injury Pattern on Incidence and Severity of Inflammatory Post-Traumatic Complications in 1277 Severely Injured Patients

Marius Keel, MD; Otmar Trentz, MD; Wolfgang Ertel, MD, University Hospital Zürich, Zürich, Switzerland

Purpose: The systemic inflammatory response syndrome (SIRS) represents the biological response of the host to severe injuries. The persistent inflammation switches the reversible host defense response into the irreversible host defense failure disease, causing multiple organ failure (MOF) and death. This retrospective study investigates the influence of different trauma patterns on the incidence and severity of inflammatory post-traumatic complications including SIRS, sepsis and MOF.

Methods: The study population included 1,277 consecutive patients (mean age: 41.1±18.4 years [mean±SD]; mean injury severity score (ISS), 19.5±10.4 points; mean APACHE II score, 13.3±7.2 points) from January 1991 to February 1996. Enrollment criteria of this study included an ISS 9 points, patient age >16 years, less than 4 hours from injury to admission, surveillance on the intensive care unit (ICU), and survival of more than 3 days. All patients were treated according to the Advanced Trauma Life Support (ATLS) guidelines. SIRS was defined according to the criteria of the American Consensus Conference and was subdivided into different grades depending upon the fulfilled SIRS criteria during 3 continuous days (2 positive criteria = SIRS 2, 3 positive criteria = SIRS 3, 4 positive criteria = SIRS 4). Sepsis was diagnosed, if all criteria of SIRS (SIRS 4) were fulfilled during at least 3 days running in combination with a septic focus or a positive blood culture. MOF was defined according the modified Goris score ( 5 points). Isolated severe injuries were defined as AIS 3 points in the absence of other injuries with an AIS 3 points.

Results: Neither SIRS nor sepsis occurred in 41% of all patients, predominantly those patients with isolated injuries. Severe SIRS and MOF were observed in a high incidence of cases in isolated head injury and abdominal injury as well as in combined torso trauma. Septic complications mostly occurred in abdominal trauma and combined torso trauma. Head injury alone and in combination with torso injuries were the major killing factors.

	no SIRS (%)	SIRS 2 (%)	SIRS 3 or 4 (%)	Sepsis (%)	MOF (%)	Mortality (%)
Head (n=315)	41#	21	38#	9	21#	13#
Thorax (n=150)	50	25	25	11	7	7
Abdomen (n=36)	50	14*	36*	31*	17*	3
Extremities (n=131)	55	23	22	8	5	3
Abdomen and head (n=7)	0§	28	72§	28*	29§	14#
Abdomen and thorax (n=30)	23§	23	54§	31*	27§	3
Thorax and head (n=60)	22§	22	56§	28§	27§	15#
Abdomen, thorax and head (n=12),	8§	0§	92§	33	58§	11#

*P <0.05 abdominal injury versus no abdominal injury; #P <0.05 head injury versus no head injury; §P<0.05 multiple versus single injury, Chi-square analysis.

Discussion: The incidence of life-threatening inflammatory complications during the post-traumatic course can be associated with certain injury pattern. Head injury with or without torso trauma represents the injury pattern at the highest risk for inflammatory complications.

Conclusion: SIRS criteria may be helpful in defining patients at risk for post-traumatic inflammatory complications and in planning of secondary surgical interventions.