Neurosurgical patients admitted to intensive care units (ICU) exhibit a systemic inflammatory response

Full text

Aims

Neurosurgical patients are at risk of multi-organ dysfunction. It was hypothesised that those patients requiring ICU admission would exhibit evidence of a systemic inflammatory response.

Methods

Over a period of 3 weeks, all neurosurgical patients (elective and emergency) admitted to a regional ICU had blood taken on the 1st and 3rd morning after admission. Blood was also taken from controls. Neutrophil (PMN) respiratory burst activity was assayed over 17.3 min using a BioOrbit 1251 Luminometer to detect diluted (1:20) whole blood chemiluminescence (CL) in the presence of luminol. Circulating and maximal CL were measured by stimulation with phorbol 1,2-myristate 1,3-acetate in the absence or presence of tumour necrosis factor alpha (TNF) respectively (Fig. 1). The peak signal for each was obtained and the maximal value dived by the circulating value. This ratio represents the capacity to increase circulating respiratory burst activity. Soluble p55 TNF receptor (anti-inflammatory marker) and interleukin 6 (IL6, pro-inflammatory marker) were measured. Clinical parameters were recorded.

Results

Median [interquartile range, IQR] APACHE II scores were 22 (17-26) and 24 (11-27) on days 1 and 3 respectively.

Conclusion

Patients admitted to ICU with neurosurgical insults have raised levels of pro-inflammatory cytokines with an increased capacity for PMN activation. Assays of PMN activation can be used as a measure of the balance between pro- and anti-inflammatory mediators.

Figure

Example of chemiluminescent assay from one patient on day 3.

Table