Performance of a new oxygen delivery device for potentially infectious critically ill patients

In patients with highly contagious diseases that are spread by respiratory droplets or air‐borne particles, the use of high‐flow oxygen may carry a significant risk of nosocomial transmission. We tested a new oxygen delivery device designed to address these problems by simulating 108 patients with sepsis and respiratory failure. The device being tested consisted of an airtight mask, a bacterial and viral filter, a T‐shaped reservoir (50 and 100 ml) and oxygen delivery tubing connected directly to the mask. When tested with a 50‐ml reservoir, a high fractional oxygen concentration was achieved: mean (SD) 0.83 (0.11) at a flow of 15 l.min^?1 oxygen. The 50‐ml reservoir, when compared with the 100‐ml reservoir, was associated with reduced carbon dioxide rebreathing (mean (SD) inspired fractional carbon dioxide concentration 2.5 (1.0) vs 3.0 (1.1), respectively, p = 0.009) and reduced inspiratory resistive work of breathing (mean (SD) 1.0 (0.6) J.l^?1 vs 1.2 (0.5) J.l^?1, respectively, p = 0.028). However, rebreathing and work of breathing were relatively high if a high respiratory rate was simulated. We conclude that the novel oxygen device we describe, equipped with the 50‐ml T‐shaped reservoir, is suitable for potentially infectious patients with type‐1 respiratory failure but without marked tachypnoea.     

生理呼吸功指导呼吸机脱机的临床意义

目的:评价生理呼吸功(WOBphy)对机械通气患者脱机的指导作用。方法:测定患者呼吸功(WOBt)和器械附加功(WOBimp)。并推算WOBphy。不符合常规脱机标准者,如WOBphy<0.70J/L,仍立即脱机拔管。结果:41例患者中28例符合常规脱机际准(常规组),WOBphy均<0.70J/L,拔管后1例再插管。13例患者不符合常规脱机标准(非常规组),WOBt高达1.37±0.50J/L,但 WOBphy均于0.70J/L,立即拔管后仪1例再插管。结论:以WOBphy<0.70J/L作为脱机标准,比常规脱机际准更准确。     

光照疗法联合保守氧疗对ICU机械通气患者谵妄的影响

目的 探讨光照疗法联合保守氧疗预防ICU机械通气患者谵妄的效果.方法 将360例ICU机械通气患者随机分为对照1组、对照2组、观察组各120例.对照1组给予光照强度为100 Lux的安慰光照,对照2组采用10 000 Lux的LED治疗灯进行光照疗法,观察组采用光照疗法联合保守氧疗.比较三组患者谵妄发生率、谵妄持续时间...     

C-反应蛋白和血清降钙素原对危重患者感染的监测价值研究

目的探讨C-反应蛋白（CRP）和血清降钙素原（PCT）对危重患者感染的监测价值。方法收集2012年10月至2013年10月本院ICU病房收治的98例危重患者,根据辅助检查结果将其分为细菌感染组（68例）和病毒感染组（30例）两组,对其PCT和CRP含量进行测定。并将细菌感染组患者随机分为观察组和对照组,每组各34例;动态监测其治疗前后PCT和CRP含量的变化情况。结果细菌感染组和病毒感染组患者的PCT平均含量分别为（3.64±0.58）μg/L和（0.37±0.35）μg/L,差异具有统计学意义（t=2.437,P〈0.05）。细菌感染组和病毒感染组患者的CRP平均含量分别为（38.27±20.55）mg/L和（37.91±20.63 mg/L）相比,差异无统计学意义（t=0.694,P〉0.05）。观察组治疗后PCT的平均含量由治疗前的（3.68±0.62）μg/L下降为（0.53±0.21）μg/L,相比于对照组由治疗前的（3.59±0.51）μg/L下降为（2.67±0.43）μg/L,下降幅度更大;观察组治疗后CRP的平均含量为（13.81±5.64）mg/L,显著低于对照组的（21.53±5.38）mg/L,差异具有统计学意义（t=5.724,P〈0.05）。结论 PCT和CRP含量的动态监测在临床应用时各有优势,二者联合应用,在对危重患者感染的诊断和治疗中具有极高的临床价值。     

Total versus tube-related additional work of breathing in ventilator-dependent patients

BACKGROUND: In tracheally intubated or tracheostomized spontaneously breathing patients, tube resistance can highly increase the patient's work of breathing. In this study we focused upon the relationship between total (WOBtot) and tube-related additional inspiratory work of breathing (WOBadd) and compared different ventilatory modalities for proper tube compensation. METHODS: In ten tracheostomized spontaneously breathing patients we measured WOBtot and WOBadd in the continuous positive airway pressure (CPAP) mode, under inspiratory pressure support of 5, 10, and 15 cmH2O in the pressure support ventilation (PSV) mode, and under flow-adjusted pressure support in the automatic tube compensation (ATC) mode. WOBadd and WOBtot were calculated on the basis of measured tracheal pressure and esophageal pressure, respectively. Inspiratory peak tracheal pressure above PEEP was taken as an estimate of pressure support beyond mere tube compensation (i.e., overcompensation). RESULTS: The percentage of the tube-related WOBadd on WOBtot in the CPAP mode was 52%. It decreased with increasing pressure support in the PSV mode from 32% (PSV 5 cmH2O) to 17% (PSV 15 cmH2O). WOBadd was only 15% of WOBtot in the ATC mode. In contrast to the other ventilatory modes, reduction of WOBadd in the ATC mode was achieved with the smallest amount of overcompensation, i.e. with minimal pressure assist beyond mere tube compensation. CONCLUSION: In tracheally intubated or tracheostomized spontaneously breathing patients, adequate compensation of tube resistance (i.e. with minimal overcompensation and minimal undercompensation) is best done by the ATC mode.     

Elastic work of breathing during continuous positive airway pressure in intubated patients with chronic obstructive pulmonary disease (theoretical analysis and experimental validation)

Background: Continuous positive airway pressure (CPAP) is known to decrease inspiratory work of breathing in patients with chronic obstructive pulmonary disease (COPD). This effect is primarily attributed to a reduction in inspiratory elastic work of breathing (Wi,el) related to a decrease in intrinsic positive end-expiratory pressure (PEEP).
Methods: The aim of this study is to design a model for computation of Wi,el on the basis of respiratory mechanics in patients with COPD, at various intrinsic PEEP- and CPAP-levels. The model was used to estimate the optimal CPAP-level with respect to the intrinsic PEEP-level in terms of reduction of Wi,el. Calculations of the decrease in Wi,el due to CPAP obtained with the model were compared to changes in Wi,el and total work of breathing (Wi,tot) determined from respiratory measurements in patients with COPD.
Results: Model calculations revealed that Wi,el was minimal whenever a CPAP-level equal to the intrinsic PEEP-level was applied. When a CPAP-level exceeding the intrinsic PEEP-level was applied, the reduction in Wi,el was less. Comparing these results to the respiratory measurements, a similar pattern in reduction of Wi,el and Wi,tot was established, although absolute values of the differences were smaller in the experimental data.
Conclusion: This study indicates that in order to reduce Wi, el in patients with COPD, intrinsic PEEP should be measured and the CPAP-level adjusted to the intrinsic PEEP-level.     

Effect of continuous positive airway pressure (CPAP) in patients with chronic obstructive pulmonary chsease (COPD) depending on intrinsic PEEP levels

The application of continuous positive airway pressure (CPAP) is known to reduce inspiratory work of breathing in intubated patients with chronic obstructive pulmonary disease (COPD). This effect is caused by a decrease in elastic work related to a reduction in intrinsic PEEP. The aim of this study was to relate the decrease in inspiratory work due to CPAP to the intrinsic PEEP levels obtained during spontaneous breathing without positive pressure. Ten intubated patients with COPD who had been ventilated for acute respiratory failure were studied. Intrinsic PEEP was determined during tracheal occlusions performed at end-expiration when the patient was breathing without positive airway pressure. Inspiratory work was computed during breathing through a circuit with a CPAP of 0.5 kPa and the same circuit without positive pressure. Intrinsic PEEP-levels ranged from 0.26 to 1.31 kPa. Compared to spontaneous breathing without positive pressure, CPAP reduced the total inspiratory work per liter of ventilation (Wltot) from 1.42±0.48 to 1.24±0.50 J·1^-1 (means±SD P <0.01). This decrease was found to be related to the intrinsic PEEP-levels: the largest reductions were found in the patients with an intrinsic PEEP-level close to the CPAP-level applied. In intubated patients with COPD, the decrease in Wltot due to a CPAP of 0.5 kPa was found to be related to the intrinsic PEEP-levels present when no positive airway pressure was applied. The intrinsic PEEP measured during tracheal occlusions could be used to estimate the effect of CPAP in these patients.     

Bi-level positive airway pressure ventilation reduces the oxygen cost of breathing in long-standing post-polio patients on invasive home mechanical ventilation

BACKGROUND: Today, patients with chronic respiratory failure are commonly treated with non-invasive bi-level positive airway pressure ventilation, supporting spontaneous breathing. However, in conformity with previous clinical routine, many post-polio patients with chronic respiratory failure are still treated with invasive (i.e. via a tracheostomy) controlled mechanical ventilation (CMV). The aim of the study was to investigate the effect of invasive bi-level positive airway pressure ventilation on the work of breathing compared with that during the patients' ordinary CMV and spontaneous breathing without mechanical support. METHODS: Nine post-polio patients on invasive (tracheostomy) nocturnal CMV were investigated. Work of breathing was analysed by assessing differences in oxygen consumption (VO2) using indirect calorimetry. Hereby, the oxygen cost of breathing during the various ventilatory modes could be estimated and related to one another. Data on energy expenditure were also obtained. RESULTS: The oxygen cost of breathing decreased by approximately 15% during bi-level positive airway pressure ventilation compared with CMV and spontaneous breathing. There was no difference between predicted (Harris-Benedict equation) and measured energy expenditure. CONCLUSION: Invasive bi-level positive airway pressure ventilation reduces the oxygen cost of breathing in long-standing tracheostomized post-polio patients, compared with CMV. Furthermore, the Harris-Benedict equation provides a reasonable prediction of energy expenditure in this group of patients.     

Effects of continuous venovenous haemofiltration-induced cooling on global haemodynamics, splanchnic oxygen and energy balance in critically ill patients.

BACKGROUND: A number of haemodialysis studies have demonstrated beneficial effects of cooler dialysates on global haemodynamics in chronic dialysis patients. However, the effects of continuous venovenous haemofiltration (CVVH)-induced cooling on regional perfusion and energy metabolism in critically ill septic patients have not been well defined. METHODS: Nine septic mechanically ventilated patients (age 40-69 years) were investigated during CVVH (ultrafiltration 30-35 ml/kg/h). Baseline data (=WARM 1) were collected when core temperature (Tc) was >37.5 degrees C; the second data set (=COLD) was obtained after 120 min of 'cooling'; and a third set (=WARM 2) was obtained after 120 min of 'rewarming'. During 'warming' (WARM 1 and 2, respectively), both substitution fluids (SFs) and 'returned' blood (RB) were warmed (37 degrees C), whereas during 'cooling', the SFs were at 20 degrees C and RB was not warmed. We measured hepatic venous (HV) haemoglobin oxygen saturation (ShvO(2)), blood gases, lactate and pyruvate. Gastric mucosal PCO(2) (PgmCO(2)) was measured by air tonometry and the gastric mucosal - arterial PCO(2) difference (PCO(2) gap) was calculated. Haemodynamic monitoring was performed with arterial and pulmonary arterial thermodilution catheters. RESULTS: Tcs were significantly altered [WARM 1, 37.9 degrees C (37.6, 38.3); COLD, 36.8 degrees C (36.3, 37.1); WARM 2, 37.5 degrees C (37.0, 38.0); P<0.001; data are median, 25th and 75th percentiles, respectively]. Systemic vascular resistance significantly increased during cooling. As a result, mean arterial pressure increased. Cooling was associated with significant decreases in heart rate, cardiac output, systemic oxygen delivery and consumption. ShvO(2) did not change [WARM 1, 51.0% (44.0, 59.5); COLD, 49.0% (42.0, 58.0); WARM 2, 51.0% (46.0, 57.0); P = NS]. The splanchnic oxygen extraction ratio, the HV lactate to pyruvate ratio, HV acid base status and PCO(2) gap remained unchanged. CONCLUSION: Mild core cooling induced by CVVH may not affect hepatosplanchnic oxygen and energy balance in septic critically ill patients, even though it affects global haemodynamics.     

Management of critically ill patients with type 2 diabetes:The need for personalised therapy

Critical illness in patients with pre-existing diabetes frequently causes deterioration in glycaemic control.Despite the prevalence of diabetes in patients admitted to hospital and intensive care units,the ideal management of hyperglycaemia in these groups is uncertain.There are data that suggest that acute hyperglycaemia in critically ill patients without diabetes is associated with increased mortality and morbidity.Exogenous insulin to keep blood glucose concentrations 10 mmol/L is accepted as standard of care in this group.However,preliminary data have recently been reported that suggest that chronic hyperglycaemia may result in conditioning,which protects these patients against damage mediated by acute hyperglycaemia.Furthermore,acute glucose-lowering to 10 mmol/L in patients with diabetes with inadequate glycaemic control prior to their critical illness appears to have the capacity to cause harm.This review focuses on glycaemic control in critically ill patients with type 2 diabetes,the potential for harm from glucose-lowering and the rationale for personalised therapy.     

3M伤口保护膜在危重症患者管道护理中的应用

目的:探讨3M伤口保护膜(3M Cavilon)在危重症患者管道护理中的临床应用效果.方法:将90例危重症患者随机分为实验组45例和对照组4 5例.在采用常规管道护理的同时,对实验组应用3M伤口保护膜进行皮肤护理,比较两种方法的皮肤护理效果.结果:实验组应用3M伤口保护膜联合常规管道护理方法的疗效明显优于常规护理的对照组.结论:应用3M伤口保护膜可有效减少管道固定时对皮肤的理化刺激,比常规护理方法更有利于保持患者皮肤的完整性,不会增加患者的疼痛和不适,节省了护理时间.     

目标导向性氧合管理:危重病患者的氧疗新方向

背景 传统的氧疗策略通过增加FiO2及机械通气以维持正常(甚至超常)的动脉氧合,并认为过多的氧气优于氧气不足,且忽视了不同个体对氧气的反应存在差异,这容易引起氧中毒及高氧血症,甚至会影响危重病患者的预后.目的 对近期目标导向性氧合管理的基础理论及临床探索进行综述,为进一步的研究及讨论提供理论支持.内容 阐述危重病患者低氧耐受机制及高氧血症的危害,进而讨论允许性低氧血症(permissive hypoxemia,PH)的理论基础及应用前景,精确动脉氧合控制(precise control of arterial oxygenation,PCAO)及FiO2安全阈值的应用价值,并介绍组织氧合监测的方法.趋向 目标导向性氧合管理旨在进一步减少氧疗的副作用,可能成为危重病患者氧疗的新方向,但还需要进一步研究证实其安全性及有效性.     

Sustained low-efficiency daily diafiltration (SLEDD-f) for critically ill patients requiring renal replacement therapy: towards an adequate therapy.

BACKGROUND: Sustained low-efficiency daily dialysis (SLEDD) is an increasingly popular renal replacement therapy for intensive care unit (ICU) patients. SLEDD has been previously reported to provide good solute control and haemodynamic stability. However, continuous renal replacement therapy (CRRT) is considered superior by many ICU practitioners, due first to the large amounts of convective clearance achieved and second to the ability to deliver treatment independently of nephrology services. We report on a program of sustained low-efficiency daily diafiltration (SLEDD-f) delivered autonomously by ICU nursing personnel, and benchmark solute clearance data with recently published reports that have provided dose-outcome relationships for renal replacement therapy in this population. METHODS: SLEDD-f treatments were delivered using countercurrent dialysate flow at 200 ml/min and on-line haemofiltration at 100 ml/min for 8 h on a daily or at least alternate day basis. All aspects of SLEDD-f were managed by ICU nursing personnel. Clinical parameters, patient outcomes and solute levels were monitored. Kt/V, corrected equivalent renal urea clearance (EKRc) and theoretical Kt/V(B12) were calculated. RESULTS: Fifty-six SLEDD-f treatments in 24 critically ill acute renal failure patients were studied. There were no episodes of intradialytic hypotension or other complications. Observed hospital mortality was 46%, not significantly different from the expected mortality as determined from the APACHE II illness severity scoring system. Electrolyte control was excellent. Kt/V per completed treatment was 1.43+/-0.28 (0.96-2.0). Kt/V(B12) per completed treatment was 1.02+/-0.21 (0.6-1.38). EKRc for patients was 35.7+/-6.4 ml/min (25.0-48.2). CONCLUSION: SLEDD-f provides stable renal replacement therapy and good clinical outcomes. Logistic elements of SLEDD-f delivery by ICU nursing personnel are satisfactory. Small solute clearance is adequate by available standards for CRRT and intermittent haemodialysis, and larger solute clearance considerable. SLEDD-f is a viable alternative to CRRT in this setting.     

慢性阻塞性肺疾病患者长期家庭氧疗的最佳证据总结

目的总结慢性阻塞性肺疾病患者长期家庭氧疗的最佳证据,为开展长期家庭氧疗实践提供指导。方法计算机检索美国国立指南库、美国胸科协会、英国胸科协会、爱尔兰胸科协会者、澳大利亚和新西兰胸科协会、Cochrane Library、PubMed、JBI、BMJ等网站及数据库关于慢性阻塞性肺疾病患者长期家庭氧疗的指南、专家共识、证据总结、系统评价和随机对照试验,由2名研究员对符合质量标准的文献进行证据提取归纳。结果共纳入10篇文献,包含指南5篇、临床决策1篇、专家共识1篇、系统评价1篇、随机对照试验2篇,形成最佳证据25条,包括长期家庭氧疗的适应证、禁忌证、长期家庭氧疗原则、评估与监测、长期家庭氧疗方案、质量控制、注意事项、健康教育等10个主题。结论建议医护人员遵循最佳证据为患者制订个体化的长期家庭氧疗管理方案,促进循证实践。     

Trigger sensitivity of Servo 300 (Siemens Elema) for pressure support ventilation in an infant

The trigger sensitivity for pressure support ventilation (PSV) with a Servo 300 ventilator was evaluated in a 6-month-old male infant ventilated with synchronized intermittent mandatory ventilation (SIMV) of 14 c.min^?1 and PSV of 4 cmH₂O. The delay time between onset of inspiration and the trigger signal was 42 and 139 msec for trigger sensitivity of –2 and –4 cmH₂O, respectively. On the former sensitivity, the inspiration was sensed by a decrease of expiratory bias flow before the airway pressure decreased to the set level. The time between the trigger signal and the flow delivery was 7 msec. The supplied volume exceeded the spontaneous breath on both trigger sensitivities. Using Servo 300, the constant expiratory bias flow, the use of a flow trigger and the mechanical improvement of the inspiratory valve contribute to reduced delay time in the trigger function, making the ventilator well suited, set in the PSV mode, even at high spontaneous respiratory rates for infants.     

急诊危重患者信息化转科交接单的研发及应用效果评价

目的 研发急诊危重患者信息化转科交接单,评价其应用效果。方法 组建研发团队,设计新增、填写、统计三大功能模块的信息化转科交接单。以便利抽样法选择急诊抢救室200例患者,按照住院时间分为对照组及试验组各100例。对照组应用传统纸质版转科交接单,试验组应用信息化转科交接单。结果 试验组转科交接单书写质量显著高于对照组,应用后,交接班护士满意度显著优于应用前,且再次核对/确定患者信息的频次显著降低（均P<0.05）。结论 急诊危重患者信息化转科交接单的应用有利于提升交接单书写质量,降低护士反复核对患者信息次数,从而提升护士工作效率及满意度。     

传染病专科医院研究生思想政治教育实践初探

研究生德育和思想政治教育在研究生培养过程中发挥引导学生树立正确的人生观、世界观、价值观的重要作用。本文针对传染病专科医院在读研究生思想状况的基本特征,通过召开导师培训会、建立学生党支部以及组织丰富多彩的学生活动等措施,对学生进行道德教育、理想教育和集体主义教育,以提高研究生整体素质。