Risk Factors in Perforated Duodenal Ulcers (Boey Score)

 

Risk factors:

(1) severe medical illness

(2) preoperative shock

(3) longstanding perforation

 

where:

• Severe medical illness included severe cardiac disease, severe pulmonary disease, renal failure, diabetes mellitus, and hepatic precoma.

• Preoperative shock was defined as a preoperative systolic blood pressure < 100 mm Hg.

• Longstanding perforations were defined as those > 24 hours, because definitive surgery was avoided in these perforations.

 

Factors not associated with increased mortality in the absence of risk factors above:

(1) old age

(2) gross peritoneal soiling

(3) length of ulcer history

 

Parameter	Finding	Point
severe medical illness	present	1
	absent	0
preoperative shock	present	1
	absent	0
longstanding perforation	> 24 hours	1
	<= 24 hours	0

 

risk score =

= number of risk factors present

= SUM(points for 3 risk factors)

 

discriminant value =

= (3.40 * (points for medical illness)) + (3.12 * (points for shock)) + (0.68 * (points for delay > 24 hours)) - 0.53

 

Interpretation:

• minimum risk score: 0

• maximum risk score: 3

• minimum discriminant value: -0.53

• maximum discriminant value: 6.67

 

Values for the discriminant values showed 3 clusters:

(1) neither severe medical illness nor shock: score -0.53 and 0.13: all survived (low risk)

(2) both severe medical illness and shock: 5.99 and 6.67: all died (high risk)

(3) either severe medical illness or shock: 2.59, 2.87, 3.27, 3.55: variable mortality rate somewhere between 10 and 46% (moderate risk)