Carotid surgery affects plasma kynurenic acid concentration: a pilot study.

BACKGROUND: An increase in plasma kynurenic acid (KYNA) concentration has been observed following surgery, inflammation, and cerebral pathologies. The aim of the present study was to analyze the changes in plasma KYNA concentration in patients undergoing carotid surgery (CS). MATERIAL AND METHODS: Adult patients undergoing elective carotid endarterectomy (CEA) or carotid angioplasty with stent placement (CAS) were studied. Plasma KYNA concentrations were analyzed before surgery and at 4 time points after CS. The amount of inflammation was measured as neutrophil-lymphocyte ratio (NLR). RESULTS: Forty patients (10 female and 30 male) aged 55-86 years of age were evaluated in this study. In patients with unstable carotid plaque, the plasma KYNA concentration was higher than in patients with stable carotid plaque. Moreover, the NLR was significantly higher in patients with unstable carotid plaque undergoing CEA than in patients undergoing CAS. Plasma KYNA concentration increased after surgery in patients undergoing CEA and CAS. There was a strong correlation between plasma KYNA concentration and NLR in patients with postoperative neurological disorders. CONCLUSIONS: CS increases plasma KYNA concentration, and changes in plasma KYNA concentration can indicate neurologic outcomes in patients undergoing CS.

The effect of crystalloid infusion on body water content and intra-abdominal pressure in patients undergoing orthopedic surgery under spinal anesthesia.

BACKGROUND: Crystalloids are frequently used for the correction of spinal anesthesia-induced hypotension, intraoperative bleeding, or vaporisation from surgical wounds. OBJECTIVES: The aim of this study was to observe the effect of perioperative crystalloid infusion on intraabdominal pressure (IAP), volume excess (VE), total body water (TBW), and extracellular body water (ECW) in patients undergoing elective orthopedic surgery under spinal anesthesia. MATERIAL AND METHODS: Adult patients undergoing hip or knee replacement were studied. Changes in VE, TBW, ECW, and IAP were observed in patients who received restrictive fluid therapy (group R) and in patients who received liberal fluid therapy (group L). IAP was measured in the urinary bladder. All parameters were measured at 4 points in time: just before anesthesia (baseline value, A); just after surgery (B); 3 h after surgery (C); and on the morning of postoperative day 1 (D). Additionally, IAP was measured after anesthesia, just before surgery (A1). RESULTS: The mean baseline values of IAP, ECW, TBW, and VE were comparable between groups L and R. The induction of anesthesia reduced IAP in both groups (p < 0.001). IAP and VE increased in both groups after surgery. Significantly higher values of IAP, however, were noted in group L at time points B, C, and D. TBW and ECW increased after surgery in group L. In group R, ECW slightly increased only at time point C. IAP strongly correlated with ECW in group L (p < 0.001, r = 0.62). CONCLUSIONS: Spinal anesthesia reduces IAP. A perioperative increase in body water content and IAP mainly depends on the volume of the infused crystalloids.