State of the upper respiratory tract in patients with stage I arterial hypertension

AIM: To study morphofunctional features of the upper airways (UAW) in wakeful patients (juveniles with arterial hypertension stage I) and genetic predisposition to UAW obstruction in sleeping patients. MATERIAL AND METHODS: The examination of 18 juveniles with arterial hypertension stage I and II normotensive juveniles included measurements of body mass index (BMI), circumference of the neck (CN), conduction of lateral cephalometry, MR imaging of UAW tissues, evaluation of nasal breathing, smoking habits and collection of family disease history. All the patients were examined by otorhinolaryngologist. RESULTS: Hypertensive juveniles appeared to have significantly higher values of BMI, CN, ANB, NAPg angles, distance between the hyoid bone and the mandible, anteroposterior tongue length in lateral projection, less values of SNPg angle (p < 0.05). Relatives of hypertensive juveniles had significantly greater prevalence of hypertension, snoring and their combination. CONCLUSION: In arterial hypertension there are some anatomofunctional grounds to UAW resistance in sleep. In addition to hereditary predisposition to hypertension, this may underlie development of wakeful systemic hypertension.     

无创正压通气与有创正压通气治疗急性呼吸衰竭的比较研究

目的　比较无创正压通气 (NPPV)和有创正压通气 (IPPV)救治急性呼吸衰竭 (ARF)的临床效果 ,评估NPPV在ARF治疗中的作用。方法　将各种原因所致ARF 5 2例患者随机分为NPPV组 (2 6例 )和IPPV组 (2 6例 ) ,在给予病因治疗同时分别实施NPPV和IPPV。观察分析两组患者在治疗过程中动脉血气变化、并发症的发生率及治疗结果。结果　NPPV组有 7例 (2 6 .9% )治疗失败转为气管插管IPPV ,其中 4例 (15 .4 % )死亡。IPPV组死亡 5例 (19.2 % ) ,两组死亡率无显著差异 (P >0 0 5 )。两组治疗有效患者在分别接受NPPV和IPPV治疗后 6h动脉血气有相似的显著改善。NPPV组患者机械通气时间和住院时间短于IPPV组 (P <0 .0 5 )。NPPV组的并发症发生率低于IPPV组 (P <0 .0 5 )。结论　在经过选择的ARF患者中 ,应用NPPV治疗的临床效果与IPPV相似。实施NPPV可缩短机械通气和住院时间 ,减少并发症。且因为无创伤性 ,NPPV可作为经过选择的ARF患者首选的通气支持治疗手段。     

A comparative study of the cardiorespiratory effects of continuous positive airway pressure breathing and continuous positive pressure ventilation in acute respiratory failure

Positive end expiratory pressure (PEEP) produces cardiopulmonary effects whether administered by controlled positive pressure ventilation (CPPV) or continuous positive airway pressure (CPAP). In eight patients with acute respiratory failure, the effects of 20 cm PEEP administered via CPPV and CPAP were compared. An esophageal balloon was used to calculate the transmural vascular pressures. The control values under mechanical ventilation with no PEEP (IPPV) for PaO₂ and QS/QT (FiO₂ being 1.0) were respectively 132±15 mmHg and 31±3%; CPPV gave a PaO₂ of 369±27 mmHg and QS/QT fo 14±1.6%, CPAP 365±18 mmHg and 18±1.3% respectively. The two different modes of ventilation (CPPV and CPAP) gave identical blood gas improvement through the same level of end expiratory transpulmonary pressure despite marked differences between absolute mean airway and esophageal pressures. Conversely, hemodynamic tolerance was very different from one technique to the other: CPPV depressed cardiac index from 3.4±0.3 to 2.4±0.2 l/min/m² as well as decreasing transmural filling pressures, suggesting a reduction in venous return. Conversely, filling pressures maintained at control values during CPAP and cardiac indexes were unchanged.Abbreviations IPPV intermittent positive pressure ventilation; mechanical ventilation (controlled mode) with zero end expiratory pressure (ZEEP) - CPPV continuous positive pressure ventilation: mechanical ventilation (controlled mode) with a positive pressure during expiration - CPAP continuous positive airway pressure; spontaneous ventilation with a positive pressure maintained during expiration - PEEP positive end expiratory pressure, whatever the ventilatory mode; spontaneous (CPAP) or mechanical (CPPV) Presented in part at the 44 th annual meeting of American College of Chest Physicians, Washington DC, October 1978     

Noninvasive positive pressure ventilation in infants with upper airway obstruction: comparison of continuous and bilevel positive pressure

Objective This study evaluated the efficacy of noninvasive continuous positive pressure (CPAP) ventilation in infants with severe upper airway obstruction and compared CPAP to bilevel positive airway pressure (BIPAP) ventilation.Design and setting Prospective, randomized, controlled study in the pulmonary pediatric department of a university hospital.Patients Ten infants (median age 9.5 months, range 3—18) with laryngomalacia (n=5), tracheomalacia (n=3), tracheal hypoplasia (n=1), and Pierre Robin syndrome (n=1)Interventions Breathing pattern and respiratory effort were measured by esophageal and transdiaphragmatic pressure monitoring during spontaneous breathing, with or without CPAP and BIPAP ventilation.Measurements and results Median respiratory rate decreased from 45 breaths/min (range 24–84) during spontaneous breathing to 29 (range 18–60) during CPAP ventilation. All indices of respiratory effort decreased significantly during CPAP ventilation compared to unassisted spontaneous breathing (median, range): esophageal pressure swing from 28 to 10 cmH₂O (13–76 to 7–28), esophageal pressure time product from 695 to 143 cmH₂O/s per minute (264–1417 to 98–469), diaphragmatic pressure time product from 845 to 195 cmH₂O/s per minute (264–1417 to 159–1183) During BIPAP ventilation a similar decrease in respiratory effort was observed but with patient-ventilator asynchrony in all patients.Conclusions This short-term study shows that noninvasive CPAP and BIPAP ventilation are associated with a significant and comparable decrease in respiratory effort in infants with upper airway obstruction. However, BIPAP ventilation was associated with patient-ventilator asynchrony.     

正压机械通气与膈肌起搏联合通气对呼吸衰竭患者呼吸力学的影响

目的 观察正压机械通气与膈肌起搏联合通气对呼吸衰竭(呼衰)患者呼吸力学的影响.方法 采用自身前后对照研究方法,以20例中枢性呼衰患者先使用常规正压机械通气30 min作为对照组,后改用正压机械通气与膈肌起搏联合通气30 min作为试验组,观察两种通气方式下患者的呼吸力学变化.结果 与对照组比较,试验组平均气道压(Paw,cm H2O,1 cm H2O=0.098 kPa)、平台压(Pplat,cm H2O)明显降低(Paw:6.1±1.3比7.3±1.8;Pplat:10.4±2.5比12.1±2.6,均P＜0.05),峰食道压力(PPEAK ES,cm H2O)、峰食道压力与基准食道压力差(dPES,cm H2O)负值明显增加(PPEAK ES:-8.3±1.9比-3.2±1.4;dPES:-11.2±2.6比-8.2±2.2,均P＜0.05),吸气末屏气期间的跨肺压(Ptp plat,cm H2O)、呼吸系统静态顺应性(Cst,ml/cm H2O)明显增加(Ptp plat:23.6±3.8比15.6±3.1 Cst:52.7±8.2比48.3±7.2,均P＜0.05),气道阻力(Raw,cm H2O·L-1·s-1)、肺部阻力(RL,cm H2O·L-1·s-1)无明显改变(Raw:2.1±0.5比2.3±0.4; RL:2.9±0.6比3.1±0.5,均P＞0.05),患者呼吸功(WOBp,J/L)明显增加、机械呼吸功(WOBv,J/L)明显降低(WOBp:0.18±0.03比0;WOBv:0.31±0.07比0.53±0.11,均P＜0.05).结论 正压机械通气与膈肌起搏联合通气进行呼吸支持可明显降低呼衰患者气道压力,增加胸腔内压负值和跨肺压,提高肺顺应性,并能降低机械通气作功,但对气道阻力无明显影响.

Abstract：

Objective To observe the effects of combining positive pressure ventilation with diaphragm pacing on respiratory mechanics in patients with respiratory failure. Methods Twenty patients with central respiratory failure were studied with cohorts. The effects on respiratory mechanics were respectively observed in patients in control group, in whom ventilation by positive pressure only, and patients in experimental group in whom ventilation was instituted by combining positive pressure ventilation with diaphragm pacing. Results Compared with control group, mean airway pressure (Paw, cm H2O,1 cm H2O= 0. 098 kPa) and plateau pressure (Pplat, cm H2O) were significantly decreased in experimental group (Paw: 6. 1±1.3 vs. 7. 3±1.8; Pplat: 10. 4±2.5 vs. 12. 1±2. 6, both P＜0. 05), while the nagative value of peak esophageal pressure (PPEAK ES, cm H2O), the nagative value of the difference between peak and basic esophageal pressure (dPES, cm H2O), transpulmonary pressure at end of inspiration hold (Ptp plat,cm H2O), static compliance (Cst, ml/cm H2O) were significantly increased in experimental group (PPEAKES:-8.3±1.9 vs. -3.2±1.4; dPES: -11.2±2.6 vs. -8. 2±2. 2; Ptp plat: 23.6±3.8 vs. 15.6±3.1; Cst:52. 7±8. 2 vs. 48. 3 ±7. 2, all P ＜ 0. 05 ). No differences were found in airway resistance (Raw,cm H2O · L-1 · s-1) and lung resistance (RL, cm H2O · L-1 · s-1) between experimental group and control group (Raw: 2.1±0.5 vs. 2.3±0.4; RL: 2.9±0.6 vs. 3.1±0.5, both P＞0.05). Work of breath by patient (WOBp, J/L) was significantly increased and work of breath by ventilator (WOBv, J/L) was significantly decreased in experimental group compared with control group (WOBp: 0. 18± 0. 03 vs. 0;WOBv: 0.31±0.07 vs. 0.53±0.11, both P＜0.05). Conclusion Compared with positive pressure ventilation, positive pressure ventilation combined with diaphragm pacing can decrease the Paw, increase intrathoracic negative pressure, transpulmonary pressure, and Cst, and decrease WOBv, while there is no effect on Raw and RL.     

无创正压通气治疗创伤性湿肺的临床研究

目的 观察无创正压通气（NIPPV）治疗创伤性湿肺的疗效。方法 选择30例行无创正压通气治疗的创伤性湿肺患者为治疗组，24例未用NIPPV治疗的创伤性湿肺患者为对照组，通过对2组患者进行心电监测、血氧饱和度、呼吸频率、血气分析等指标的监测，比较2组患者呼吸频率和动脉血气参数、肺部病变吸收时间、气管插管率、ICU住院时间及预后。结果 30例创伤性湿肺患者经NIPPV治疗后动脉血气指标与临床表现明显改善（P〈0．01）；与对照组相比，NIPPV治疗组患者临床症状改善时间、肺部病变吸收时间、ICU住院时间明显缩短（P〈0．01），肺实变率显著减低（P〈0．05），但2组患者气管插管率和病死率差异却无显著性。结论 NIPPV通过调节压力支持与呼吸末正压水平，早期应用可明显改善创伤性湿肺患者病情及缩短病程，但并不能改善其预后。     

单肺通气时持续气道正压对动脉氧合的影响

目的 利用自制的气道正压装置,对单肺通气下开胸病人的无通气肺施加志气道正压,观察无通气肺接受不同水平的持续气道正压时对动脉氧合的影响。方法 １９例需在单肺通气下开胸手术的病人（ＡＳＡ：１－２级）,随机分成２组,组１（ｎ＝１０）,对无通气肺施加０．２９４ｋＰａ（３ｃｍＨ２Ｏ）的气道持续正压（ＣＰＡＰ－３）,组２（ｎ＝９）;对无 敢肺施加０．４９０ｋＰａ（５ｃｈｍＨ２Ｏ）的气道持续正压（ＣＰＡＰ－５）     

气道压力释放通气和持续气道正压开放肺的比较

目的探讨气道压力释放通气（APRV）与持续气道正压（CPAP）通气两种通气模式实施肺复张策略治疗急性呼吸窘迫综合征（ARDS）对血流动力学、肺力学和氧代谢指标的影响。方法选择ARDS行机械通气及脉搏轮廓法持续血流动力学监测的患者15例，随机实施APRV模式肺复张或CPAP模式肺复张，每隔4h复张1次。其中APRV组设定高水平压力（Phigh）为35cm H2O（1cm H2O=0．098kPa），低水平压力（Plow）为压力-容积（P—V）曲线的下拐点（LIP）；CPAP组设定CPAP为35cm H2O；两组持续时间均为40s。记录复张前后的肺力学、氧代谢指标以及复张时的血流动力学变化。结果在APRV模式下行肺复张时心脏指数（CI）轻度下降，且持续时间较短。两种复张模式均可使肺顺应性等力学参数及氧合明显改善，以APRV模式尤为明显。结论采用APRV模式进行ARDS肺复张治疗可避免镇静剂的使用，对血流动力学干扰较小，对肺力学及氧合的改善优于CPAP模式。     

鼻塞式持续气道正压通气治疗新生儿呼吸衰竭的临床研究进展

介绍了鼻塞式持续气道正压通气治疗新生儿呼吸衰竭的临床研究进展 ,重点阐述了鼻塞式持续气道正压通气的优点、使用时间、工作原理、分类、治疗效果、临床应用、护理及局限性     

Obstructive sleep apnea in patients with stage I arterial hypertension]

AIM: To study sleep breathing in young men with arterial hypertension stage I. MATERIAL AND METHODS: Somnological history, night cardiorespiratory monitoring, 24-h monitoring of arterial pressure (AP) and ECG were analysed in 34 young men with arterial hypertension (AH) of the first degree and 12 normotensive young men. RESULTS: Hypertensive young men had a higher index apnea/hypopnea, mean duration of apnea/hypopnea (p < 0.05), maximal desaturation (p < 0.1), indirect parameters of inspiratory apnea, they snored more and woke up in sleep more frequently, their night hypertension was more than daytime. This was observed even in patients with overweight. CONCLUSION: All hypertensive young men examined had indirect signs of obstructive sleep apnea. The triggering role in it of the lungs and subclinical obstruction of upper airways in AH is suggested.     

Hypoxic therapy of arterial hypertension in patients with different variability of arterial pressure

Sixty two patients with essential hypertension stage II were divided into two groups. 32 patients of group 1 received combined therapy including a course of inhalations of gas hypoxic mixture containing 10% oxygen and conventional medication (ACE inhibitors, beta-blockers, calcium antagonists, diuretics). 30 patients of group 2 (controls) were given medication alone. 24-h monitoring of arterial pressure (AP) and echocardiography suggested that high AP variability (APV) in hypertensive subjects leads to more significant changes in left ventricular and atrial structure and function typical for hypertensive heart. In high VAP, its night values are subnormal while daytime values are high in patients on combined medication and hypoxic therapy. The patients on standard medication had significantly low VAP at night while their daytime VAP tended to decrease. VAP positively correlated with hypertensive load. In high VAP hypoxic and drug therapies are less effective.     

无创正压通气治疗急性低氧性呼吸衰竭前瞻性队列研究

目的 探讨无创正压通气(NPPV)对急性低氧性呼吸衰竭(AHRF)的治疗作用和治疗失败的危险因素.方法 采用前瞻性队列研究方法,收集2004年1月-2007年12月北京朝阳医院呼吸重症监护病房应用NPPV治疗AHRF患者的临床资料,根据NPPV成功与否将患者分为成功组和失败组,比较两组患者的基本临床资料、NPPV模式和时间以及NPPV前和2 h、24 h的生命体征、血气分析和氧合指数(PaO2/FiO2)的变化.结果 ①59例患者NPPV成功率为62.7%(37/59).②与NPPV失败组比较,成功组平均年龄及因肺部感染导致AHRF比例较低(P均<0.01).NPPV前成功组PaO2/FiO2与失败组无显著差异,但成功组NPPV后2 h和24 h PaO2/FiO2均较失败组显著改善(P<0.05和P<0.01),且NPPV后24 h成功组心率和呼吸频率均较失败组显著降低(P均<0.01).③logistic回归分析显示:NPPV失败的危险因素为年龄≥60岁[比值比(OR)=8.30,95%可信区间(CI)2.49～27.60,P=0.002]、呼衰诱因为肺部感染(OR=6.19,95%CI 1.90～20.20,P=0.027)、NPPV后2 h PaO2/FiO2<150 mm Hg(1 mm Hg=0.133 kPa,OR=3.65,95%CI 1.20～11.04,P=0.044)、NPPV后24 h心率>100次/min(OR=7.45,95%CI 2.15～25.58,P=0.010)和呼吸频率>30次/min(OR=7.26,95%CI 1.88～24.49,P=0.018).结论 NPPV可作为无绝对禁忌证AHRF的一线呼吸支持方式,但对老龄和肺部感染诱发的AHRF患者失败率较高;短期应用NPPV治疗后呼吸、循环和氧合状况无显著改善的AHRF患者,应及早改为有创通气.     

无创正压通气治疗急性呼吸窘迫综合征的前瞻性队列研究

目的 观察和评价无创正压通气(NPPV)对急性呼吸窘迫综合征(ARDS)的疗效和安全性.方法 采用前瞻性队列研究,分析2004年1月-2007年12月北京朝阳医院呼吸重症监护病房(RICU)使用NPPV治疗ARDS患者的临床资料.结果 ①31例患者纳入本研究,其中男23例,女8例;年龄20～76岁,平均(49±17)岁;NPPV前急性生理学与慢性健康状况评分系统Ⅰ(APACHE Ⅰ)评分(14±8)分,氧合指数(PaO2/FiO2)(123±32)mm Hg(1 mm Hg=0.133 kPa).②NPPV成功率为74.2%(23/31),非肺部感染所致ARDS的成功率显著高于肺部感染所致ARDS(100%比60%,P=0.017).③与NPPV前相比,成功组NPPV治疗后2 h及24 h的心率(HR)、呼吸频率(RR)及PaO2/FiO2均有显著改善(P均<0.01),而失败组上述指标不但无显著改善,尚伴有动脉血二氧化碳分压(PaCO2)逐渐升高(P<0.05).患者均无NPPV相关的严重并发症.结论 对于无NPPV禁忌的ARDS患者,NPPV可作为一线呼吸支持手段;但对于在短期应用NPPV后生命体征及动脉血气无显著改善者,尤其是肺部感染诱发ARDS时应及早改为有创通气.     

双水平正压通气和持续气道正压通气治疗呼吸窘迫综合征早产儿的临床疗效比较

目的 比较双水平正压通气和持续气道正压通气治疗赣州地区呼吸窘迫综合征(RDS)早产儿的临床疗效.方法 选取2017年5月至2020年4月该院收治的RDS早产儿60例为研究对象,按照随机数字表法随机分为观察组(双水平正压通气)和对照组(持续气道正压通气),各30例.对比两种治疗方式下患儿血气分析指标、并发症发生率,以及无创正压总通气时间、住院时间、有创呼吸机上机率、后期停氧时间.结果 治疗前两组患儿二氧化碳分压(PaCO2)、氧分压(PaO2)差异无统计学意义(P>0.05),治疗后观察组患儿PaCO2、PaO2优于对照组,差异有统计学意义(P<0.05).观察组患儿并发症发生率(3.33％)低于对照组(16.67％),差异有统计学意义(P<0.05).观察组无创正压总通气时间、住院时间及后期停氧时间与对照组相比,差异无统计学意义(P>0.05);观察组有创呼吸机上机率低于对照组,差异有统计学意义(P<0.05).结论 双水平正压通气可有效改善RDS早产儿血气分析指标,降低有创呼吸机上机率及并发症发生率,同时并未延长患儿住院时间、后期停氧时间以及无创正压通气时间,有一定的应用价值.     

持续气道正压通气治疗儿童呼吸衰竭的疗效观察

目的：探讨鼻塞式持续气道正压通气（CPAP）治疗儿童呼吸衰竭的疗效。方法42例不同原因引起的呼吸衰竭患儿使用常规氧疗、鼻塞式 CPAP 及呼吸机进行治疗,比较治疗前后的临床情况（气喘、气促、三凹征）、动脉血气[pH、动脉血氧分压（PaO2）、动脉血二氧化碳分压（ PaCO2）]的变化及住院时间、预后等。结果常规氧疗有效率为50%, CPAP 有效率为79%,呼吸机有效率为100%。住院时间 CPAP 组为8.9 d,较常规氧疗（12.5 d）和呼吸机治疗（12.7 d）均明显缩短（P 〈0.05）。结论鼻塞式 CPAP 治疗儿童呼吸衰竭疗效显著,可以减少有创通气的应用及缩短住院时间,避免了有创呼吸支持对儿童气道的损害,具有无创伤、易操作、低费用、高疗效等优点,值得推广应用。     

Non‐invasive positive pressure ventilation in patients with acute respiratory failure

Non‐invasive positive pressure ventilation is an emerging modality in contemporary critical care practice. Perhaps the most widely utilized and familiar form of non‐invasive positive pressure ventilation is mask continuous positive airway pressure. Other common modes include mask Bi‐level positive airway pressure and mask pressure support ventilation. All feature the delivery of positive airway pressure via a mask (full‐face, naso‐oral or nasal), and a patient‐controlled respiratory cycle. The physiological benefits of non‐invasive positive pressure ventilation suggested by a number of studies include improved oxygenation, decreased work of breathing, improved ventilation and perfusion matching, decreased fatigue, and increased minute ventilation. The utilization of non‐invasive positive pressure ventilation has now been reported for a variety of clinical indications. In most, randomized trials are lacking, and the benefits and preferred mode of non‐invasive positive pressure ventilation are still to be elucidated. In general, in patients that are candidates for endotracheal intubation, non‐invasive positive pressure ventilation should be used as a way to possibly avoid endotracheal intubation rather than as an alternative to endotracheal intubation. Whilst the benefit of non‐invasive positive pressure ventilation appears to be established in patients with chronic obstructive airways disease with hypercapnic acute respiratory failure, one of the major unresolved issues is whether one modality is significantly better than the others. Unfortunately, the question of whether Bi‐level positive airway pressure is better than continuous positive airway pressure in this clinical scenario has not been satisfactorily addressed in any large randomized and controlled clinical trial. Further, there is no ‘gold standard’ for predicting success with non‐invasive positive pressure ventilation, although several studies have looked at this aspect.     

水凝胶敷料在持续无创正压通气患者眼部护理中的应用

目的：研究水凝胶敷料用于持续无创正压通气患者眼部的应用效果。方法选择持续使用无创呼吸机辅助通气治疗的呼吸衰竭患者47例,按随机数字表法将患者随机分为试验组（ n＝22）和对照组（ n＝25）。对照组给予常规护理,试验组在此基础上,使用无创通气时即给予眼部敷贴水凝胶敷料,观察两组患者的临床护理效果。结果使用无创通气后第7天,试验组患者眼部舒适度评分为（76．91±3．02）分,对照组为（72．56±2．86）分,差异有统计学意义（t＝5．067,P＜0．01）;试验组患者发生异物感3例、眼睑肿胀1例,对照组分别为11,9例,差异均有统计学意义（χ2值分别为5．159,5．162;P＜0．05）。结论持续无创呼吸机辅助通气患者在治疗期间敷贴水凝胶敷料可增加患者舒适度、减少眼部不适等症状的发生。     

无创正压通气治疗慢性阻塞性肺疾病合并呼吸衰竭

目的观察无创正压通气(NPPV)在治疗慢性阻塞性肺疾病急性加重期(AECOPD)合并Ⅱ型呼吸衰竭患者中的临床疗效。方法治疗组42例AECOPD合并Ⅱ型呼吸衰竭患者在常规治疗的基础上进行NPPV治疗,对照组40例仅给予常规治疗(抗炎、解痉、吸氧等);观察血气指标、心率、血压、呼吸频率及住院时间的变化。结果治疗组和对照组在治疗后动脉血气pH值、动脉血二氧化碳分压(PaCO2)、动脉血氧分压(PaO2)、心率和呼吸频率与治疗前比较均有明显改善。治疗组在降低PaCO2、呼吸频率和提高PaO2方面比对照组效果更明显。结论NPPV治疗AECOPD合并Ⅱ型呼吸衰竭能更有效地降低PaCO2、呼吸频率,提高PaO2,缩短住院时间。     

Non-invasive ventilation in acute respiratory failure: a randomised comparison of continuous positive airway pressure and bi-level positive airway pressure

Objectives: To determine whether there is a difference in required duration of non-invasive ventilation between continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BiPAP) in the treatment of a heterogeneous group of emergency department (ED) patients suffering acute respiratory failure and the subgroup of patients with acute pulmonary oedema (APO). Secondary objectives were to compare complications, failure rate, disposition, length of stay parameters, and mortality between the treatments.

Methods: This prospective randomised trial was conducted in the emergency departments of three Australian teaching hospitals. Patients in acute respiratory failure were randomly assigned to receive CPAP or BiPAP in addition to standard therapy. Duration of non-invasive ventilation, complications, failure rate, disposition, length of stay (hospital and ICU), and mortality were measured.

Results: 101 patients were enrolled in the study (CPAP 51, BiPAP 50). The median duration of non-invasive ventilation with CPAP was 123 minutes (range 10–338) and 132 minutes (range 20–550) for BiPAP (p = 0.206, Mann-Whitney). For the subgroup suffering APO, 36 were randomised to CPAP and 35 to BiPAP. For this group the median duration of non-invasive ventilation for CPAP was 123 minutes (range 35–338) and 133 minutes (range 30–550) for BiPAP (p = 0.320, Mann-Whitney).

Conclusions: These results suggest that there is no significant difference in the duration of non-invasive ventilation treatment between CPAP and BiPAP when used for the treatment of acute respiratory failure in the ED. There was also no significant difference between the groups in secondary end points.