### Description

Nishida et al identified prognostic factors for patients with severe traumatic injury to the liver who underwent hepatic surgery. The outcomes measured were the overall risk of death, hemorrhagic death and septic death. The authors are from the Osaka Police Hospital in Osaka, Japan.

Parameters:

(1) Glasgow coma score (ranges from 3 to 15)

(2) postoperative BUN in mg/dL

(3) number of associated organ injuries

(4) preoperative ALT in IU/L

(5) preoperative systolic blood pressure in mm Hg

(6) preoperative base excess in mEq/L

(7) preoperative platelet count per 10^4 per cubic mm (per µL)

(8) presence or absence of intestinal injuries (0 if absent, 1 if present)

where:

• A platelet count of 200,000 per µL would be 20 * 10^4 per cubic mm (per µL), or 20 in the equation.

• The reference ranges and methods for BUN and ALT were not given.

• A very negative base excess is associated with acidosis.

probability for overall death =

= 0.5830 – (0.03656 * (Glasgow Coma Score)) + (0.009954 * (postoperative BUN)) + (0.05494 * (number of associated organ injuries)) + (0.0001175 * (preoperative ALT)) – (0.002967 * (preoperative systolic blood pressure))

probability for hemorrhagic death =

= 0.1787 + (0.0001755 * (preoperative ALT)) - (0.03228 * (preoperative base excess)) - (0.01272 * (preoperative platelet count))

where:

• Equation 2 in the text shows (-0.0001755) and a positive 0.01272. However, the coefficients in Table 3 on page 391 are the opposite. If the equation as given is used, answers inconsistent with the text are returned.

probability for a septic death

= 0.4878 – (0.004259 * (preoperative systolic blood pressure)) + (0.212 * (intestinal injuries))

NOTE: I wondered if the y was the value for the logistic regression equation (see below), but when this is tried incorrect results are returned for the data in Table 1 on page 390.

probability of death =

= 1 / (1 + EXP((-1) * (y)))

Performance:

• Overall death: sensitivity 86%, specificity 100%, accuracy 98%.

• Hemorrhagic death: sensitivity 75%, specificity 100%, accuracy 98%.

• Septic death: sensitivity 67%, specificity 100%, accuracy 97%.

Limitations:

• The adjusted R^2 values were 0.34 for septic death, 0.67 for hemorrhagic death and 0.71 for overall death.

• The prognosis would be affected by surgical techniques employed.

• The absence of data on methodology for BUN and ALT may limit transportability.