Plasma PTX3 levels in sickle cell disease patients, during vaso occlusion and acute chest syndrome (data from Saudi population).

BACKGROUND: Sickle cell disease (SCD) is a chronic, incurable hereditary disease. The vaso-occlusive crisis (VOC) is the most frequently occurring acute complication in sickle cell patients and accounts for the majority of SCD-related hospital admissions. Another major complication is the potentially fatal acute chest syndrome (ACS). The prototypic long pentraxin-3 (PTX3), an acute phase protein and a key component of innate immunity, is linked to ischemia-induced inflammation, a condition incriminated in SCD complications. AIM: To investigate the expression of PTX3 in stable SCD and VOC patients and to assess its relation to the development and progression of ACS. SUBJECTS AND METHODS: We conducted this study on 160 patients with confirmed SCD (20 stable SCD and 140 in VOC), and 10 healthy age- and sex-matched controls. Patients were diagnosed as SCD by high-performance liquid chromatography. PTX3 levels were assessed using enzyme-linked immunosorbant assay. RESULTS: In the stable state, all 20 SCD patients had PTX3 levels (range = 0.9-2.1 ng/ml; median = 1.1) comparable to those of healthy controls (range = 0.8-2.0 ng/ml; median = 1.0) (P > 0.05). During the VOC, plasma PTX3 significantly increased (range = 8.7-37.2 ng/ml; median = 22.3) (P < 0.01). Out of 140 VOC patients, 15 (10.7%) developed ACS and four required mechanical ventilation, of which two died. The median plasma level of PTX3 (22.3 ng/ml) was set as a cut-off value to stratify patients into low- and high-PTX3 expressers. Of the 140 VOC patients, 43 (30.7%) had PTX3 levels >22.3 ng/ml, of these, 13 patients developed ACS (13/43; 30.2%); of the remaining 97 patients who had PTX3 ≤22.3 ng/ml, only two patients (2/97; 2.1%) progressed to ACS, with a further increment in PTX3 in all of them. PTX3 levels were correlated with length of hospital stay in VOC patients and markers of lung injury in ACS patients. CONCLUSION: PTX3 levels were higher in SCD patients in VOC, being associated with longer hospital stay. Higher initial PTX3 concentrations were related to the development of ACS with a further increase in PTX3 levels observed upon progression to ACS. Thus, PTX3 could be used as a subjective method to predict occurrence and severity of SCD acute complications.

Analgesic properties of a dexmedetomidine infusion after uvulopalatopharyngoplasty in patients with obstructive sleep apnea.

BACKGROUND: Dexmedetomidine is an alpha(2) -adrenergic agonist with sedative and analgesic properties. This study aimed to investigate if the use of a continuous dexmedetomidine infusion with i.v. morphine patient-controlled analgesia (PCA) could improve postoperative analgesia while reducing opioid consumption and opioid-related side effects. METHODS: In this prospective randomized, double-blinded, controlled study, 39 patients with obstructive sleep apnea syndrome undergoing uvulopalatopharyngoplasty were assigned to two groups. Group D (dexmedetomidine group) received a loading dose of dexmedetomidine 1 µg.kg(-1) i.v., 30 minutes before the anticipated end of surgery, followed by infusion at 0.6 µg.kg(-1) h(-1) for 24 hours. Group P (placebo group) received a bolus and infusion of placebo. In both groups, postoperative pain was initially controlled by i.v. morphine titration and then PCA with morphine. Cumulative PCA morphine consumption, pain intensities, sedation scores, cardiovascular and respiratory variables and opioid-related adverse effects were recorded for 48 hours after operation. RESULTS: Compared with placebo group, patients in the dexmedetomidine group required 52.7% less PCA morphine during the first 24 hours postoperatively, with significantly better visual analogue scale scores, less incidence of respiratory obstruction (5 vs. 12 patients, respectively; P = .037) and longer time to first analgesic request (21 (11) vs. 9 (4) minutes; P = .002). Fewer patients in group D experienced nausea and vomiting than those in group P (7 vs. 24 patients, respectively; P < .05). CONCLUSION: Continuous dexmedetomidine infusion may be a useful analgesic adjuvant for patients susceptible to opioid-induced respiratory depression.