目的分析优化院内综合急救流程对行直接经皮冠状动脉介入治疗(PCI)的急性ST段抬高型心肌梗死(STEMI)患者救治效果的影响,探讨影响院内综合急救流程的主要因素和改进措施。方法纳入2017年7月至2018年12月青岛大学附属医院确诊的STEMI患者。2017年7月至2018年3月在胸痛中心建设、优化综合急救流程前行直接PCI患者为改进前组(92例),2018年4月至2018年12月在胸痛中心建设、优化综合急救流程后行直接PCI患者为改进后组(87例)。观察并对比两组从进入医院大门到球囊扩张血管再疏通(D to B)时间、住院天数及随访3个月主要不良心血管事件(MACE,包括再发心肌梗死、心律失常、心原性休克、心力衰竭)发生率。结果改进前组患者节点1[(17.21±5.11)min比(4.44±0.76)min,P<0.001]、节点2[(10.40±4.49)min比(5.68±0.77)min,P<0.001]、节点3[42.50(23.00,74.00)min比22.00(18.00,25.00)min,P<0.001]、节点4[(40.99±8.70)min比(22.71±4.01)min,P<0.001]、节点5[(5.51±1.04)min比(3.82±0.71)min,P<0.001]、节点9[(74.45±2.41)min比(16.83±0.92)min,P<0.001]、节点10[(22.78±4.12)min比(17.82±0.95)min,P<0.001]时间和D to B时间[(155.10±67.94)min比(83.20±14.74)min,P<0.001]均显著长于改进后组患者,差异均有统计学意义。两组节点6、节点7、节点8时间比较,差异均无统计学意义(均P>0.05)。改进后组患者节点1[(4.44±0.76)min比10 min,P<0.001]、节点2[(5.68±0.77)min比10 min,P<0.001]、节点5[(3.82±0.71)min比10 min,P<0.001]、节点9[(16.83±0.92)min比20 min,P<0.001]时间较标准节点时间有很大改进,差异均有统计学意义,虽然节点3、节点4、节点8时间与标准节点时间比较,差异均无统计学意义(均P>0.05),但均符合标准时间。改进后组患者D to B整体平均时间[(83.20±14.74)min比90 min,P<0.05]短于标准时间,差异有统计学意义。改进后组患者随访3个月后MACE发生率(10.3%比25.0%,P=0.011)显著低于改进前组患者,平均住院时间[(6.67±0.77)d比(8.04±2.52)d,P<0.001]显著短于改进前组患者,差异均有统计学意义。结论优化院内综合急救流程明显缩短了D to B时间,使得STEMI患者3个月总体心血管不良事件发生率显著降低。 相似文献
Purpose/Objective: For complex planning situations where organs at risk (OAR) surrounding the target volume place stringent constraints, intensity-modulated treatments with photons provide a promising solution to improve tumor control and/or reduce side effects. One approach for the clinical implementation of intensity-modulated treatments is the use of a multileaf collimator (MLC) in the “step and shoot” mode, in which multiple subfields are superimposed for each beam direction to generate stratified intensity distributions with a discrete number of intensity levels. In this paper, we examine the interrelation between the number of intensity levels per beam for various numbers of beams, the conformity of the resulting dose distribution, and the treatment time on a commercial accelerator (Siemens Mevatron KD2) with built-in MLC.
Methods and Materials: Two typical, clinically relevant cases of patients with head and neck tumors were selected for this study. Using the inverse planning technique, optimized treatment plans are generated for 3–25 evenly distributed coplanar beams as well as noncoplanar beams. An iterative gradient method is used to optimize a physical treatment objective that is based on the specified target dose and individual dose constraints assigned to each organ at risk (brain stem, eyes, optic nerves) by the radiation oncologist. The intensity distribution of each beam is discretized within the inverse planning program into three to infinitely many intensity levels or strata. These stratified intensity distributions are converted into MLC leaf position sequences, which can be subsequently transferred via computer link to the linac console, and can be delivered without user intervention. The quality of the plan is determined by comparing the values of the objective function, dose-volume histograms (DVHs), and isodose distributions.
Results: Highly conformal dose distributions can be achieved with five intensity levels in each of seven beams. The merit of using more intensity levels or more beams is relatively small. Acceptable results are achievable even with three levels only. On average, the number of subfields per beam is about 2–2.5 times the number of intensity levels. The average treatment time per subfield is about 20 s. The total treatment time for the three-level and seven-beam case with a total of 39 subfields is 13 min.
Conclusion: Optimizing stratified intensity distributions in the inverse planning process allows us to achieve close to optimum results with a surprisingly small number of intensity levels. This finding may help to facilitate and accelerate the delivery of intensity-modulated treatments with the “step and shoot” technique. 相似文献