Patient Body Mass Index and Occupational Radiation Doses to Circulating Nurses During Coronary Angiography.

BACKGROUND: Patient BMI is associated with radiation doses received by interventional cardiologists, yet the association between patient BMI and nurse radiation doses is unknown. This study evaluated the association between patient body mass index (BMI) and nurse radiation doses during coronary angiography. METHODS: Nurse radiation doses were collected by real-time dosimeters during consecutive coronary angiography procedures and are reported as the personal dose equivalent (Hp10). Patient radiation doses were estimated using dose area product (DAP). Patient BMI was categorized in kg/m2 as <25.0, 25.0-29.9, 30.0-34.9, 35.0-39.9, and ≥40. Multiple regression analysis determined procedural factors independently association with nurse radiation doses. RESULTS: In 643 consecutive coronary angiography procedures, patient radiation doses increased significantly across increasing patient BMI categories (p < 0.001). Compared to a patient BMI <25, a patient BMI ≥40 was associated with a 2.3-fold increase in DAP (p < 0.001). Significant differences were also observed in nurse radiation doses across patient BMI categories (p = 0.036). Compared to a patient BMI <25, a patient BMI ≥40 was associated with a 4.0-fold increase in nurse radiation dose (BMI < 25: 0.3 [0.1, 1.3] µSv; BMI ≥ 40: 1.2 [0.2, 2.9] µSv; p = 0.003). By multiple regression analysis, each 1-unit kg/m2 increase in patient BMI was associated with a 3.3% increase in nurse radiation dose (p = 0.002). CONCLUSIONS: Patient BMI was significantly associated with nurse radiation doses during coronary angiography. These observations may have important implications on nurse radiation safety, especially in the setting of the ongoing obesity epidemic.

Impact of patient obesity on radiation doses received by scrub technologists during coronary angiography.

BACKGROUND: The impact of patient obesity on scrub technologist radiation dose during coronary angiography has not been adequately studied. METHODS: Real-time radiation exposure data were prospectively collected during consecutive coronary angiography cases. Patient radiation dose was estimated by dose area product (DAP). Technologist radiation dose was recorded by a dosimeter as the personal dose equivalent (Hp (10)). Patients were categorized according to their body mass index (BMI): <25.0, lean; 25.0-29.9, overweight; ≥30.0, obese. The study had two phases: in Phase I (N = 351) standard radiation protection measures were used; and in Phase II (N = 268) standard radiation protection measures were combined with an accessory lead shield placed between the technologist and patient. RESULTS: In 619 consecutive coronary angiography procedures, significant increases in patient and technologist radiation doses were observed across increasing patient BMI categories (p < 0.001 for both). Compared to lean patients, patient obesity was associated with a 1.7-fold increase in DAP (73.0 [52.7, 127.5] mGy × cm2 vs 43.6 [25.1, 65.7] mGy × cm2, p < 0.001) and a 1.8-fold increase in technologist radiation dose (1.1 [0.3, 2.7] µSv vs 0.6 [0.1, 1.6] µSv, p < 0.001). Compared to Phase I, use of an accessory lead shield in Phase II was associated with a 62.5% reduction in technologist radiation dose when used in obese patients (p < 0.001). CONCLUSIONS: During coronary angiography procedures, patient obesity was associated with a significant increase in scrub technologist radiation dose. This increase in technologist radiation dose in obese patients may be mitigated by use of an accessory lead shield.

In vitro and in vivo study of sustained nitric oxide release coating using diazeniumdiolate-oped poly(vinyl chloride) matrix with poly(lactide-co-glycolide) additive.

Nitric oxide (NO) is an endogenous vasodilator as well as natural inhibitor of platelet adhesion and activation that can be released from a NO donor species, such as diazeniumdiolated dibutylhexanediamine (DBHD/N2O2) within a polymer coating. In this study, various Food and Drug Administration approved poly(lactic-co-glycolic acid) (PLGA) species were evaluated as additives to promote a prolonged NO release from DBHD/N2O2 within a plasticized poly(vinyl chloride) (PVC) matrix. When using an ester-capped PLGA additive with a slow hydrolysis time, the resulting coatings continuously release between 7-18×10-10 mol cm-2 min-1 NO for 14 d at 37°C in PBS buffer. The corresponding pH changes within the polymer films were visualized using pH sensitive indicators and are shown to correlate with the extended NO release pattern. The optimal combined diazeniumdiolate/PLGA-doped NO release (NOrel) PVC coating was evaluated in vitro and its effect on the hemodynamics was also studied within a 4 h in vivo extracorporeal circulation (ECC) rabbit model of thrombogenicity. Four out of 7 control circuits clotted within 3 h, whereas all the NOrel coated circuits were patent after 4 h. Platelet counts on the NOrel ECC were preserved (79 ± 11% compared to 54 ± 6% controls). The NOrel coatings showed a significant decrease in the thrombus area as compared to the controls. Results suggest that by using ester-capped PLGAs as additives to a conventional plasticized PVC material containing a lipophilic diazeniumdiolates, the NO release can be prolonged for up to 2 weeks by controlling the pH within the organic phase of the coating.