Superimposed inspiratory work of the Siemens Servo 300 ventilator during continuous positive airway pressure

Objective To compare the superimposed inspired work of breathing (SIW) of the Siemens Servo 300 ventilator with the Siemens Servo 900 C ventilator.Design Comparisons made at continuous positive airway pressure (CPAP) levels of 0, 4, and 8 cmH₂O, and at trigger sensitivities of –1 and –2 cmH₂O, and flow triggering.Setting General intensive care unit in a University teaching hospital.Patients 7 patients receiving CPAP.Results At all levels of CPAP, the SIW was significantly less with the Siemens Servo 300 ventilator as compared to the Siemens Servo 900 C ventilator despite similar trigger sensitivities. No significant difference was found in the SIW of the Servo 300 ventilator when comparing trigger sensitivities of –1 cmH₂O, –2 cmH₂O, and flow triggering. Different levels of CPAP had no effect on SIW.Conclusions The Siemens Servo 300 ventilator entails less superimposed inspiratory work of breathing than the Siemens Servo 900 C ventilator.     

An anti-pollution modification for the Cape-Waine Anaesthetic Ventilator

Most anaesthetic equipment needs to be modified to fulfil anti-pollution recommendations. A method of modifying a Cape-Waine Anaesthetic Ventilator is described in detail showing what parts need to be replaced or removed. A list of the new parts required together with their cost is given and the modification can be made by suitably trained hospital staff or the manufacturers.     

临床相关因素对呼吸机相关性肺炎预后的影响

目的：确定临床相关因素对呼吸机相关性肺炎（VAP）预后的影响。方法：前瞻性临床研究120例连续性发生的VAP。病原学诊断是根据气管内吸出物、防污染毛刷和肺泡灌洗采集标本定量培养结果。用软件统计包（SPSS）中的逐步logistic回归模型分析影响VAP预后的流行病学和临床相关因素。结果：VAP患者总病死率为17％（20／120）,与VAP相关病死率为14％（17／120）。单因素分析中年龄超过45岁、致命性基因疾病、先前使用抗生素、使用激素、住院日期超过9天、休克、有慢性阻塞性肺病史与VAP病死率有显著相关性。进一步逐步logistic回归分析显示只有先前使用抗生素（P＜0．0001,OR＝9．2）是影响VAP患者病死率的独立相关因素。将VAP病原菌作为一项自变量,重复作逐步logistic回归分析,先前使用抗生素因素被“高危”病原菌因素所替代。结论：VAP患者先前使用抗生素与病死率增高密切相关主要是由于抗生素的使用导致耐药菌产生。因此为减少VAP患者死亡危险性,应严格管理机械通气患者抗生素的使用。     

老年早发、晚发通气机相关肺炎分析

目的：比较老年早发、晚发通气机相关肺炎(VAP)患者的临床特点。方法：回顾性调查了解放军总医院老年早发、晚发VAP患者，比较其通气、实验室检查和药物使用等情况。结果：早发VAP30例，晚发VAP46例，晚发VAP患者的血PH、血白蛋白含量较低，PaCO2较高，机械通气时间也明显长于早发VAP患者。两组患者的致病菌分布无差别。结论：老年VAP的抗生素治疗不能根据VAP发生早晚来选择。     

慢性阻塞性肺病患者高碳酸血症状态下撤机的可行性

目的：探讨慢性阻塞性肺病（COPD）呼吸衰竭机械通气患者在高碳酸血症状况下撤机的可行性和安全性。方法：62例接受机械通气支持治疗的COPDⅡ型呼吸衰竭患者,按照撤机前血气分析动脉CO2分压[p（CO2）]水平分为高碳酸血症组[p（CO2）≥60mmHg]和对照组[p（CO2）〈60mmHg],分别为24例和38例。比较两组一般情况、呼吸力学及撤机前12h、6h、撤机前即刻及撤机后1h、6h、24h、48h动脉血气分析结果等指标。结果：两组患者撤机前反映通气力学的RR、Vt、RR/Vt、Crs等指标差异无统计学意义（P〉0.05）。撤机前后各时间段pH和p（O2）差异亦无统计学意义（均P〉0.05）,p（CO2）和HCO3ˉ高碳酸血症组显著高于对照组（P〈0.01）,撤机前即刻高碳酸血症组患者p（CO2）水平范围62.3～86.9mmHg。高碳酸血症组撤机成功22例（91.67/）,对照组撤机成功34例（89.47/）,两组撤机成功率差异无统计学意义（P〉0.05）。结论：单纯的高碳酸血症并非撤机的禁忌。     

Testing of adult and paediatric ventilators for use in a magnetic resonance imaging unit

We have assessed the performance of a series of ventilators (modified versions of the ventiPAC, paraPAC and babyPAC ventilators; SIMS pneuPAC Ltd, Luton, UK) in a magnetic resonance imaging (MRI) scanning environment, with MR safety and compatibility issues being addressed. Following initial modifications to remove ferromagnetic components and replace them with MR-safe materials, all three ventilators performed well in a series of tests in static magnetic fields up to 2 T. Ventilator performance was unaffected by static fields, switching gradients or radio frequency fields within the MR suite. Furthermore, the devices produced no degradation of image quality when used during MR scanning. We discuss management strategies for the care of critically ill ventilated patients during MR procedures.