P-BN49 The predictive role of white cell and platelet count for infective complications following splenectomy

Abstract

Abstract Background Temporary elevation of white cell count (WCC) and platelets are commonly observed after splenectomy and can therefore make it difficult for the surgeon to distinguish a normal physiological response from potential infection. Clinicians are often misled by elevated post-operative WCC after splenectomy, resulting in delayed discharges and prolonged unnecessary hospital stays for patients. The aim of this study was to establish what constitutes a normal rise in WCC and platelets after splenectomy. Methods All 127 patients who had undergone a splenectomy between July 2016 and January 2021 were identified from a search of our centre's hospital episode statistics data. WCC and platelet count on post-operative days one to seven as well as at least one long-term follow-up result count were identified from electronic hospital records. Hospital records were searched for data on pre-operative steroid administration and peri-operative infections. These cohort data were retrospectively analysed in SPSS using stepwise logistic regression, correlation analysis, and T-tests, as well as descriptive statistics. Results 86 (68%) patients underwent an elective splenectomy and 41 (32%) an emergency splenectomy. 35 (27.6%) patients developed infections post-operatively, while 92 (72.4%) did not. Logistic regression suggested that a raised WCC (above 17.5x109/L) at day 3 post-op was a significant predictor of infection (p < 0.001): average WCC at day 3 for patients with infection was 20.00x109/L (SD = 6.23x109/L) compared to 14.86x109/L (SD = 4.01x109/L) for those without. Infective outcomes were not influenced by whether the surgery was emergency or elective. Overall, average WCCs were 9.63x109/L pre-operatively and 15.07x109/L long-term post-operatively. Even in the absence of infection, splenectomy led to a long-term rise in WCC of 3.8x109/L from baseline, to an average of 13.0x109/L [SD = 5.41x109/L): a T-test on the 56 patients without infection and with both pre-op and long-term WCCs showed a mean rise of 3.76x109/L, p < 0.0001). Platelet count was not correlated with infection, though platelet counts rose from a mean of 261 × 109/L (SD = 103.4x109/L) pre-operatively to 581 × 109/L (SD = 236.3x109/L) at 7-day and 619 × 109/L (SD = 293.5x109/L) at long-term follow up across all patients – an average increase of 357 × 109/L, which did not significantly differ between patients with and without infective complications. Conclusions A rise in WCC and platelet count is normal post-splenectomy. A rise in WCC>17.5x109/L on day 3 post-splenectomy is strongly correlated with infection (regardless of trauma or platelet count). Long-term follow up suggests that while much of the WCC increase is transient, WCC remains higher than pre-operatively, as does platelet count, in post-splenectomy patients. A raised WCC or platelet count without signs of infection should not preclude timely discharge in otherwise well patients.