Objective To analyze the relationship between the catheter to vein ratio and the formation of peripheral insertion of central venous catheter (PICC) related upper extremity deep venous thrombosis (PICC-UEDVT) in cases having undergone PICC in patients at intensive care unit (ICU) and further identify the best optimal ratio cut-off point to reduce the incidence of PICC-UEDVT.Methods A retrospective study was conducted, including 69 patients having undergone PICC with complete clinical data admitted to the Department of Critical Care Medicine of the First Affiliated Hospital of Nanchang University from August 2013 to December 2016; their ages were > 18 years old and catheter indwelling times were > 1 week; the patients' basic information, disease related laboratory parameters and catheter insertion situation were collected. According to the occurrence of PICC-UEDVT, they were divided into PICC-UEDVT group and non PICC-UEDVT group; the receiver operating characteristic (ROC) curve of the catheter to vein ratio versus the incidence ofPICC-UEDVT was plotted to assess the optimal ratio to reduce the incidence of PICC-UEDVT.Results In the 69 patients, there were 7 patients in the PICC-UEDVT group and 62 patients in the non PICC-UEDVT group, the incidence of PICC-UEDVT being 10.14%. Four, 5 and 6 French (Fr) catheters were indwelled in 43, 23 and 3 cases respectively, and the range of catheter to vein ratio was 20% - 67%. The comparisons between PICC-UEDVT group and non PICC-UEDVT group in various aspects were as follows: the incidence of DVT in the PICC-UEDVT group was significantly higher than that in non PICC-UEDVT group [42.9% (3/7) vs. 6.5% (4/62)], the rate of using vasopressor drugs [57.14% (4/7) vs. 17.74% (11/62)], D-dimer level [mg/L: 9.0 (3.0, 12.3) vs. 1.8 (1.0, 3.6)], patients of indwelling 5Fr catheter [71.4% (5/7) vs. 29.0% (18/62)] and the percentage of patientsapplying catheter to vein ratio 45%-67% [57.14% (4/7) vs. 17.74% (11/62)] in PICC-UEDVT group were all higher than those in the non PICC-UEDVT group, the differences being statistically significant (allP < 0.05). ROC analysis showed that the catheter to vein ratio 44% was the optimal cut off or critical point, the area under the ROC curve (AUC) at that point was 0.755, 95% confidence interval (95%CI) = 0.554-0.955, sensitivity = 71.4% and specificity = 79.0%; compared with the patients using 45%-67% catheter to vein ratio, the incidence of PICC-UEDVT was 6.182 times higher than those using the ratio 20%-44% [odds ratio (OR) = 6.182, 95%CI = 1.208-31.634,P = 0.036]; however, there was no significant difference in incidence of PICC-UEDVT between 20%-32% and 33%-44% (P = 1.000).Conclusion It is found that the 44% catheter to vein ratio was the optimal critical point to reduce the incidence of PICC-UEDVT, possessing relatively high sensitivity and specificity; applying <44% catheter to vein ratio can decrease the risk of PICC-UEDVT occurrence in patients at ICU.

OBJECTIVE: To investigate the effect of low-frequency pulsed electromagnetic fields (PEMF) on the maturation and mineralization of rat cranial osteoblasts and its relation to IGF-1R/NO signaling pathway. METHODS: The rat osteoblasts were isolated and cultured and randomly divided into blank control group, PEMF group, GSK group (IGF-1R blocker) and PEMF+GSK group. The cells were treated with 50 Hz 0.6 mT PEMF for 1.5 h/d. After 3 d of PEMF treatment, the expressions of protein kinase (AKT), inducible nitric oxide synthase (iNOS) and cGMP-dependent protein kinase (PKG) were detected by Western blotting; on 6 d of PEMF treatment alkaline phosphatase (ALP) activity was determined; on 12 d of PEMF treatment the calcification nodule formation was demonstrated by Alizarin red staining. RESULTS: NO level was significantly increased in rat osteoblasts treated with 50 Hz 0.6 mT PEMF for 1.5 h/d. Western blot analysis showed that the expressions of AKT, iNOS and PKG protein in PEMF group were higher than those in the control group (all <0.01); the ALP activity was increased(<0.05), and the PEMF group had the largest area of Alizarin red staining (<0.01). The expressions of AKT, iNOS and PKG protein in GSK group were lower than those in the control group; the ALP activity was decreased (<0.05), and the GSK group had the least area of Alizarin red staining (<0.01). The expressions of AKT, iNOS, PKG protein, the ALP activity and the area of Alizarin red staining in PEMF+GSK group were between PEMF group and GSK group. CONCLUSIONS PEMF may enhance the maturation and mineralization of rat cranial osteoblasts through IGF-1R/NO signaling pathway.
Animals ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Electromagnetic Fields ; Nitric Oxide ; metabolism ; Osteoblasts ; radiation effects ; Rats ; Receptor, IGF Type 1 ; metabolism ; Signal Transduction ; radiation effects