Inappropriate ventilator triggering caused by an in-line suction catheter

OBJECTIVE: To examine the phenomenon of inappropriate triggering caused by an in-line suction catheter. DESIGN: We used a test lung to assess inappropriate triggering in four ventilators with both pressure and flow triggering. RESULTS: With pressure triggering, inappropriate triggering occurred only in the presence of PEEP. However, with flow triggering, inappropriate triggering occurred both with and without PEEP. Inappropriate triggering did not occur in a model of severe airflow obstruction. CONCLUSION: In-line suction catheters may lead to inappropriate triggering and potentially dangerous increases in delivered ventilation.     

Effects of different triggering systems and external PEEP on trigger capability of the ventilator

Objective The triggering capability of both the pressure and flow triggering systems of the Servo 300 ventilator (Siemens-Elema, Sweden) was compared at various levels of positive end-expiratory pressure (PEEP), airway resistance (R_aw), inspiratory effort and air leak, using a mechanical lung model.Design The ventilator was connected to a two bellows-in-series-type lung model with various mechanical properties. Lung complicance and chest wall compliance were 0.03 and 0.12 l/cmH₂O, respectively. R_aw was 5, 20 and 50 cmH₂O/l/s. Respiratory rate was 15 breaths/min. To compare the triggering capability of both systems, the sensitivity of pressure and flow triggered pressure support ventilation (PSV) was adjusted to be equal by observing the triggering time at 0 cmH₂O PEEP and 16 cmH₂O of pressure support (PS) with no air leak. No auto-PEEP was developed. In the measurement of trigger delay, the PS level ranged from 16 to 22 cmH₂O to attain a set tidal volume (V_T) of 470 ml at a R_aw of 5, 20 and 50 cmH₂O/l/s. The PEEP level was then changed from 0, 5 and 10 cmH₂O at a PS level of 17 cmH₂O and R_aw of 5 and 20 cmH₂O/l/s, and the trigger delay was determined. The effect of various levels of air leak and inspiratory effort on triggering capability was also evaluated. Inspiratory effort during triggering delay was estimated by measurements of pressure differentials of airway pressure (P_aw) and driving pressure in the diaphragm bellows (P_driv) in both systems.Measurements and results There were no significant differences in trigger delay between the two triggering systems at the various PEEP and R_aw levels. At the matched sensitivity level, air leak decreased trigger delay in both systems, and additional PEEP caused auto-cycling. A low inspiratory drive increased trigger delay in the pressure sensing system, while trigger delay was not affected in the flow sensing system. The P_aw and P_driv differentials were lower in flow triggering than in pressure triggering.Conclusions With respect to triggering delay, the triggering capabilities of the pressure and flow sensing systems were comparable with and without PEEP and/or high air-way resistance at the same sensitivity level, unless low inspiratory drive and air leak were present. In terms of pressure differentials, the flow triggering system may require less inspiratory effort to trigger the ventilator than that of the pressure triggering system with a comparable triggering time. However, this difference may be extremely small.     

Sonographic findings of extensor digiti minimi triggering caused by thickened extensor retinaculum

Trigger finger is a common well recognized condition and involves the flexor tendons at the A1 pulley in the palm. Triggering of the extensor tendons is a very rare clinical entity. We report a rare case of extensor triggering of little finger caused by constriction of the extensor digiti minimi by a markedly thickened extensor retinaculum (ER) at the wrist, well delineated dynamically by real-time high-resolution ultrasound. The patient underwent release of thickened ER and was asymptomatic immediately.

Electronic supplementary material

The online version of this article (doi:10.1007/s40477-014-0140-3) contains supplementary material, which is available to authorized users.     

在重症肺炎致呼吸衰竭抢救中无创呼吸机辅助呼吸的护理应用

目的探讨重症肺炎致呼吸衰竭抢救中使用无创呼吸机辅助呼吸患者的临床护理疗效。方法选取本院收治的147例患者,随机分为观察组(n=74)和对照组(n=73)。对照组给予常规护理,观察组在对照组的基础上给予综合性护理干预,观察比较2组护理满意度、HR、RR、p H值、p(O_2)、p(CO_2)、氧合指数,通气时间、住院时间、并发症发生率、拔管成功率及生活质量情况。结果观察组护理满意度为82.43%,明显高于对照组的67.12%(P0.05)。观察组HR、RR、p(CO_2)均低于对照组(P0.05),p(O_2)和氧合指数显著高于对照组(P0.05);通气时间、住院时间及并发症均显著低于对照组(P0.05),拔管成功率显著高于对照组(P0.05)。护理干预后,观察组SF-36评分由治疗前的(54.63±16.33)分显著提高至(63.82±13.72)分(P0.05),明显高于对照组(P0.05);其中一般健康状况、生理机能、生理职能、躯体疼痛、精力均明显提高(P0.05),且均高于对照组(P0.05)。结论综合性护理干预重症肺炎致呼吸衰竭抢救中使用无创呼吸机辅助呼吸患者护理满意度高,可显著提高机体p(O_2)和氧合指数,缩短通气时间与住院时间,改善患者生活质量,值得推广应用。     

Inspiratory effort and measurement of dynamic intrinsic PEEP in COPD patients: Effects of ventilator triggering systems

Objective To investigate effects of ventilator triggering systems (pressure and flow triggering: PT and FT) on measurement of dynamic intrinsic PEEP (PEEPi_dyn) and patient-ventilator interaction in patients with chronic obstructive pulmonary disease during weaning from mechanical ventilation.Design Prospective study.Setting Medical/surgical intensive care unit of an academic hospital.Patients and participants 6 COPD patients with acute respiratory failure ready to wean.Measurements We measured flow, airway opening, esophageal and gastric pressures. Minute ventilation, breathing pattern and pressure time product (PTP) of the respiratory muscles and of the diaphragm were obtained during spontaneous ventilation through a mechanical ventilator (Puritan-Bennett 7200ae). Two triggering systems, namely PT and FT, were evaluated.Results The inspiratory muscles effort necessary to overcome the triggering system overestimated PEEPi_dyn measurement of an amount equal to 49±2 and 58±3% during respectively pressure and flow triggering. FT increased tidal volume and minute ventilation and decrease PTP/b and PTP/min of the respiratory muscles and diaphragm.Conclusions To correctly measure PEEPi_dyn, the inspiratory effort produced to overcome PEEPi and to trigger the ventilator must be discriminated. Application of flow triggering requires less effort to initiate inspiration and provide a positive end-expiratory pressure level that is able to unload the respiratory muscles by reducing PEEPi. With flow triggering higher minute ventilation are obtained in COPD patients during the weaning phase.Supported in part by the Ministero dell' Università e della Ricerca Scientifica e Tecnologica     

Comparative bench study of triggering,pressurization, and cycling between the home ventilator VPAP II and three ICU ventilators

OBJECTIVE: To compare triggering, pressurization, and cycling of the home ventilator VPAP II with those of three ICU ventilators (Evita 4, Galileo, and Servo 300). DESIGN AND SETTING: Two-compartment lung model study in a research laboratory, university hospital. METHODS: One compartment was driven by an ICU ventilator to mimic "patient" inspiratory effort, while the other was connected to the tested ventilator. Pressure support of 10, 15, 20, and 25 cmH2O, and inspiratory efforts of 5, 10, 15, 20, and 25 cmH2O (inspiratory time 1 s) were used in normal, obstructive, and restrictive conditions. Triggering delay (Td), triggering workload, pressurization at 300 and 500 ms, and difference between the "patient's" inspiratory time and that of the ventilator were analyzed. RESULTS: No difference was noted in triggering workload between VPAP II, Evita 4, and Galileo while Servo 300 had a lower value. Pressurization at 300 ms on Evita 4 and Servo 300 reached 75% of the ideal value, on Galileo 35%, and on VPAP II 45%. Pressurization at 500 ms on Evita 4 and Servo 300 reached 85% of the ideal value, on Galileo 50%, and on VPAP II 55%. Cycling was delayed in obstructive conditions and premature in restrictive conditions with each of the devices. CONCLUSIONS: The VPAP II performed as well as one ICU ventilator and less well than two. Home devices for noninvasive ventilation in acute respiratory failure outside the ICU could prove attractive as they are smaller, less costly, and easier to use than ICU machines.     

微支气管肺泡灌洗液可溶性髓细胞触发受体对呼吸机相关性肺炎早期诊断价值

目的 探讨采用微支气管肺泡灌洗技术获得支气管肺泡灌洗液中可溶性髓系细胞触发受体-1(sTREM-1)表达对呼吸机相关性肺炎早期诊断价值.方法 对112例在机械通气前无肺部感染,行机械通气48 h后出现发热、气管支气管内分泌物增多脓性,临床疑诊VAP患者,通过微支气管肺泡灌洗技术获取BALF液体,测定BALF中sTREM-1、血清CRP水平及临床肺部感染积分(CPIS).应用受试者工作特征(ROC)曲线来分析上述指标对VAP的诊断价值.结果 与非VAP患者比较,VAP患者在临床疑诊当天BALF中sTREM-1、血清CRP水平及CPIS评分明显升高(P＜0.01).行ROC曲线分析,显示BALF中sTREM-1水平153.18 pg/mL时诊断VAP有最佳的敏感性和特异性,分别为86.49％和84.21％,ROC曲线下面积为0.882,诊断价值优于血清CRP和CPIS(ROC曲线下面积分别为0.723和0.823).结论 BALF中sTREM-1水平＞ 153.18 pg/mL时,有利于早期诊断VAP.     

Inadvertent positioning of pacemaker leads in the pericardium

A patient had a dual chamber pacemaker with endocardial leads implanted chronically. The lead position on chest X ray and the ECG pattern indicated lead malposition, but a CT scan and transesophageal echocardiography were nondiagnostic. Venography indicated that both leads were in the mediastinal and pericardial space.     

呼吸机集束干预策略对呼吸机相关性肺炎的影响

目的:探讨呼吸机集束化干预策略在预防呼吸机相关性肺炎(VAP)中的影响。方法:采用回顾性研究方法,对2008年10月~2010年10月收住ICU的机械通气病人共286例进行集束化治疗与护理。所有病人采取抬高床头、每天"唤醒计划"、消化性溃疡的预防、深静脉血栓的预防等集束化干预策略。通过对体温、痰量和性状、血象、胸部X线片及下呼吸道细菌学检查监测,观察VAP的发生率及死亡率;取本院ICU2006年1月~2007年12月机械通气病人262例作为对照组。结果:机械通气病人集束化干预后,病人VAP的发生率较对照组有显著下降(P<0.01),死亡率较对照组下降(P<0.05)。结论:集束化干预策略能有效降低VAP的发生。     

Cycling of the mechanical ventilator breath

Patient-ventilator interaction is a key element in optimizing mechanical ventilation. The change from inspiration to expiration is a crucial point in the mechanically ventilated breath, and is termed "cycling." Patient-ventilator asynchrony may occur if the flow at which the ventilator cycles to exhalation does not coincide with the termination of neural inspiration. Ideally, the ventilator terminates inspiratory flow in synchrony with the patient's neural timing, but frequently the ventilator terminates inspiration either early or late. Most current mechanical ventilators include adjustable cycling features that, when used in conjunction with waveform graphics, can enhance patient-ventilator synchrony.     

应用清洗消毒器集中处理呼吸机管道的效果观察

目的观察全自动清洗消毒器集中处理呼吸机管道及配件的效果。方法全院各科室使用的呼吸机管道及配件均采用全自动清洗消毒器集中清洗消毒,检查清洗后的物品清洁度并进行细菌培养。结果清洗消毒呼吸机管道及配件共558套次,全部达到清洁要求,细菌培养均未检出存活菌,达到高效消毒水平,符合《消毒技术规范》对呼吸机管道消毒的要求。结论清洗消毒器集中处理呼吸机管道及配件,能确保清洗消毒效果,利于医院感染控制及员工自我防护,且节约成本,便于统一管理。     

Inadvertent Detection of 60-Hz Alternating Current by an Implantable Cardioverter Defibrillator

LEE, S.W., et al. : Inadvertent Detection of 60-Hz Alternating Current by an Implantable Cardioverter De-fibrillator. A patient with an ICD received therapies from his ICD while exercising in an indoor swimming pool. Interrogation of the ICD revealed inappropriate detection of 60-Hz alternating current artifact and delivery of ICD therapies.     

呼吸机集束化干预策略对恶性肿瘤患者呼吸机相关性肺炎的预防效果

目的 探讨呼吸机集束化干预策略在恶性肿瘤患者呼吸机相关性肺炎（VAP）的预防作用.方法 采用前瞻性研究方法,对我院147例ICU的机械通气恶性肿瘤患者进行集束化干预策略,采取抬高头部≥30°角体位、每日唤醒并评估患者进行脱机实验,预防消化性溃疡以及深静脉血栓的预防等措施.比较实施前后患者的机械通气时间、VAP发生率.结果 采用集束化干预策略后,患者VAP的发生率有所下降,机械通气时间缩短,入住ICU时间较对照组明显缩短.结论 呼吸机集束化干预策略可预防恶性肿瘤患者VAP的发生,值得临床推广应用.     

Mucocele of the surgically isolated esophagus

A large esophageal mucocele causing chest pain developed in a 26-year-old woman who had undergone esophageal bypass surgery and gastric interposition because of involvement by scleroderma. Computed tomographic (CT) scans showed the mucocele as an elongated mediastinal mass which spontaneously reduced in size during conservative management. The clinical and radiological features of this unusual postsurgical complication are herein reviewed.