Definition of a new score for severity of generalized Neisseria meningitidis infection

Neisseria meningitidis infection may present as meningitis or as severe, fulminant sepsis. In order to classify individual patients early according to the expected course of the disease, we developed a score named Neisseria sepsis index [NESI]. The NESI was defined using the parameters heart rate, mean arterial blood pressure, base excess and presence of acute subcutaneous bleeding and/or skin necroses (minimal value [= no evidence for sepsis] NESI 0; maximum value [= most severe sepsis] NESI 8). Seventeen patients with documented, systemic N. meningitidis infection were prospectively assessed for the terminal complement complex (TCC), serum tumour necrosis factor alpha (TNF alpha) levels (as laboratory parameters for severity of sepsis) and NESI score. The evaluation was immediately performed when the patients were admitted to the hospital. The 17 patients showed the following distribution of data: NESI 0 (n = 4), NESI 1 (n = 6), NESI 2 (n = 0), NESI 3 (n = 1), NESI 4 (n = 2), NESI 5 (n = 2), NESI 6 (n = 0), NESI 7 (n = 1), NESI 8 (n = 1). Mortality was 4/17 patients, all had NESI > or = 5. TCC values ranged from 647-6461 ng/ml (normal range: 130-360 ng/ml); and was not correlated to NESI. TNF alpha values ranged from 10-910 pg/ml and were correlated to NESI (r2 = 0.71, n = 17, P < 0.001). In patients with fatal outcome, TNF alpha was 600 +/- 160 pg/ml (mean +/- SEM) and in surviving patients 130 +/- 50 pg/ml (mean +/- SEM). TNF alpha was increased in 15/17 patients when compared to normal controls (< 27 pg/ml). CONCLUSION. The NESI is based on few clinical, objective data, that are available in every hospital. NESI appears to offer an instrument: (1) for making decisions in regard to appropriate monitoring and treatment of vital organ function; and (2) for assessing the quality of care for this life-threatening infection.