THE SIMMS' MODIFIED PROGNOSTIC INDEX IN THE PREDICTION OF POSTOPERATIVE IN PATIENTS UNDERGOING GASTROINTESTINAL SURGERY J.H.Hohbiss,

A.Buxton, D.E.F.Tweedle (Department of Surgery, University Hospital of Iter, England).

nutritional assessment was performed in 94 patients prior to gastro- Lrgery. A prognostic index was calculated for each patient using Simms' of Mullen's formula. The incidence of postoperative wound infection, on and mortality was recorded. Four patient groups were analysed: t developed wound infection; (ii) those that developed chest infection; hat developed either a wound or a chest infection; (iv) those that died. mostic index of each of these groups was compared to the mean prognostic groups that did not develop these respective complications. The mean ~ex of the chest infection group and of the group that developed either chest infection was significantly higher than the mean prognostic index that did not develop these complications (p= 0.05 and 0.03 respectively).

:nostic index of the group that developed a wound infection and of the ed was higher than that of those that did not develop these complications, rences were not statistically significant. A discriminate analysis t the critical value of the prognostic index was 45 in all groups. Using 13% of the wound infection group, 57% of the chest infection group, 60% that developed either wound or chest infection and 57% of the group that rectly classified. This method of calculating a prognostic index has iscriminater or individual prognosis in this series. Its main use is as a measurement of nutritional status for research purposes.

PERFORMANCE OF PROGNOSTIC NUTRITIONAL INDICES S. Burton, R. Kay, J.M. . Smith, H.F. Woods (Departments of Probability & Statistics, Surgery and , University of Sheffield, U.K.

)le to have some method of selecting patients who are at risk following result of nutritional deficiences who might therefore benefit from ~herapy. A number of methods of selection have been described including the /tritional indices (Buzby et al 1980; Blackburn et al 1977; Simms et al 1982) methods may not allow detection of all patients at risk and may not identify to benefit from nutritional therapy. Therefore, a critical statistical the prognostic indices in current use has been undertaken with the aim of ~ir (a) reliability, (b) discriminatory power and (c) performance. From we have concluded that: i) The prognostic indices will identify individual

risk" for postoperative complications, ii) The indices fail to discriminate zategories to any large extent, iii) Because the majority of patients in a high risk, mostly elderly surgical population the role of nutritional in the pathogenesis of complications may be difficult to identify. It is recommended that a fuller investigation of both the 'normal' population undergoing less major surgery should be performed. This will not only claim made for nutritional indices but may also improve the accuracy of the ~rms of prognosis and use in nutritional monitoring.