NORMAL PLATELET COUNT AT ADMISSION IN ACUTE MENINGOCOCCAL DISEASE DOES NOT EXCLUDE A FULMINANT COURSE

Objective: To determine the value of the platelet count at admission f or the assessment of the severity of disease in acute meningococcal in fections. Design: Retrospective and prospective, descriptive patient s tudy. Setting: University Hospital Intensive sive Care Unit (ICU). Pat ients: All patients (n = 92) with acute meningococcal disease from 198 5 to 1997, who arrived at the ICU within 12 h after hospital admission and had more than one platelet count during the first 12 h. Measureme nts and results: After admission, platelets dropped in 95 % of the pat ients. At admission, 2/41 (5 %) of the non-hypotensive patients and 13 /51 (25 %) of the hypotensive patients had platelets fewer than 100 x 10(9)/l. During the following 12 h, these percentages increased to 15 % and 71 %, respectively. Fatalities had, at admission, a median plate let count of 111 x 10(9)/l (range, 19-302 x 10(9)/l), whereas the nadi r, occurring at median 7.0 h (range, 1.3-12 h), was 31x10(9)/l (range, 12-67 x 10(9)/l). Plasma TNF measured shortly after admission, correl ated better with the platelet nadir (r = -0.65, p < 0.0001) than with the platelet count at admission. Similarly, serum lactate correlated b etter with the platelet nadir. Conclusions: As platelets drop after ad mission, the use of the platelet count at admission for the assessment of the prognosis in acute meningococcal disease may be misleading. Fr equently repeated platelet counts are a better tool for evaluating the severity of disease.