Neuraminidase alters red blood cells in sepsis.

OBJECTIVE: To investigate the influence of neuraminidase, an enzyme that cleaves sialic acid from the red blood cell (RBC) membrane, on RBC shape and biochemistry in critically ill patients. DESIGN: Prospective, observational study and in vitro laboratory study. SETTING: A 31-bed medico-surgical department of intensive care and a university-affiliated cell biology laboratory. SUBJECTS: Acutely ill patients with and without sepsis and healthy volunteers. INTERVENTIONS: Blood sampling in volunteers. MEASUREMENTS AND MAIN RESULTS: Neuraminidase activity was measured using a fluorescent assay. RBC shape was assessed by the second coefficient of dissymmetry of Pearson using a flow cytometry technique at 25 degrees C. Intraerythrocytic 2,3-diphosphoglycerate and lactate contents were also measured. Neuraminidase activity was significantly higher in septic patients compared with nonseptic patients and healthy volunteers (5.42 [4.85-6.00] vs. 4.53 [4.23-5.23] and 1.26 [0.83-1.83] mU/mL; all p < 0.05). Neuraminidase treatment modified the RBC shape in vitro in a dose-response fashion, and most of these alterations were present after 10 hours of incubation. Incubation of RBCs with phosphatidylinositol phospholipase C modified RBC shape and increased sialic acid concentrations in the supernatant, suggesting a leakage of neuraminidase from the RBC membrane. Alterations in shape were associated with increased 2,3-diphosphoglycerate (0.46 +/- 0.25 vs. 0.19 +/- 0.05 mumol/mL; p = 0.006) and lactate content (0.81 +/- 0.07 vs. 0.66 +/- 0.05 mmoL/L; p = 0.002). CONCLUSIONS: In sepsis, desialylation under the influence of increased neuraminidase activity may contribute to the alterations in RBC rheology. Inhibition of neuraminidase may represent a new therapeutic option to ameliorate RBC rheology and perhaps oxygen delivery to the cells.

Comparison of parecoxib and proparacetamol in endoscopic nasal surgery patients.

PURPOSE: The aim of the study was to compare the efficacy of parecoxib for postoperative analgesia after endoscopic turbinate and sinus surgery with the prodrug of acetaminophen, proparacetamol. MATERIALS AND METHODS: Fifty American Society of Anesthesiology (ASA) physical status I-II patients, receiving functional endoscopic sinus surgery (FESS) and endoscopic turbinectomy, were investigated in a prospective, randomized, double-blind manner. After local infiltration with 1% mepivacaine, patients were randomly allocated to receive intravenous (i.v.) administration of either 40 mg of parecoxib (n=25) or 2 g of proparacetamol (n=25) 15 min before discontinuation of total i.v. anaesthesia with propofol and remifentanil. A blinded observer recorded the incidence and severity of pain at admission to the post anaesthesia care unit (PACU) at 10, 20, and 30 min after PACU admission, and every 1 h thereafter for the first 6 postoperative h. RESULTS: The area under the curve of VAS (AUC(VAS)) calculated during the study period was 669 (28-1901) cm x min in the proparacetamol group and 635 (26-1413) cm x min in the parecoxib group (p=0.34). Rescue morphine analgesia was required by 14 patients (56%) in the proparacetamol group and 12 patients (48%) in the parecoxib (p >or= 0.05), while mean morphine consumption was 5-3.5mg and 5-2.0 mg in the proparacetamol groups and parecoxib, respectively (p >or= 0.05). No differences in the incidence of side effects were recorded between the 2 groups. Patient satisfaction was similarly high in both groups, and all patients were uneventfully discharged 24 h after surgery. CONCLUSION: In patients undergoing endoscopic nasal surgery, prior infiltration with local anaesthetics, parecoxib administered before discontinuing general anaesthetic, is not superior to proparacetamol in treating early postoperative pain.