Fraticelli Amanda Tarabini, Lellouche François, L'her Erwan, Taillé Solenne, Mancebo Jordi, Brochard Laurent
Service de Réanimation Médicale, Groupe Hospitalier Albert Chenevier Henri Mondor, Créteil, France.
Crit Care Med. 2009 Mar;37(3):939-45. doi: 10.1097/CCM.0b013e31819b575f.
To test the short-term physiologic effects (indexes of respiratory effort, ventilation, and gas exchange), leaks, patient-ventilator asynchrony, and comfort of four noninvasive ventilation (NIV) facial, oronasal, or oral interfaces with major differences in internal volume.
Prospective, short-term, crossover randomized physiologic study.
Medical intensive care unit in a university hospital.
Fourteen consecutive patients receiving NIV for either hypoxemic (n = 7) or hypercapnic (n = 7) acute respiratory failure.
Four interfaces, tested randomly over consecutive sequences, had very high (977 mL), high (163 mL), moderate (84 mL), or virtually no internal volume (mouthpiece). The pressure level was increased in two patients with the larger mask, and was decreased in all patients when using the mouthpiece.
Despite differences in internal volume, no apparent dead space effect was observed on minute ventilation, work of breathing, or arterial CO2 levels. Compared with baseline, NIV was uniformly successful in reducing indexes of respiratory effort: the pressure-time product of the respiratory muscles decreased from a median (25th-75th interquartile range) of 179 (158-285) cm H2O.sec.min to values between 91 and 111 during NIV, with no differences between masks (p = 0.84). Few differences were observed in terms of arterial blood gases and breathing pattern. Leaks and patient-ventilator asynchronies were greater with the mouthpiece, and comfort with this interface was deemed poor for most patients.
The internal volume of the masks had no apparent short-term dead space effect on gas exchange, minute ventilation, or patient's effort, suggesting that, with the exception of mouthpiece, interfaces may be interchangeable in clinical practice provided adjustment of the ventilatory device parameters are performed.
测试四种内部容积有显著差异的无创通气（NIV）面部、口鼻或口腔接口的短期生理效应（呼吸努力、通气和气体交换指标）、漏气情况、患者与呼吸机不同步情况以及舒适度。
前瞻性、短期、交叉随机生理研究。
大学医院的医学重症监护病房。
14例因低氧血症（n = 7）或高碳酸血症（n = 7）急性呼吸衰竭接受无创通气的连续患者。
四个接口，在连续序列中随机测试，其内部容积分别为非常大（977 mL）、大（163 mL）、中等（84 mL）或几乎没有（口含器）。两名使用较大面罩的患者压力水平升高，使用口含器时所有患者压力水平降低。
尽管内部容积不同，但在分钟通气量、呼吸功或动脉二氧化碳水平上未观察到明显的死腔效应。与基线相比，无创通气在降低呼吸努力指标方面均取得成功：呼吸肌的压力 - 时间乘积从中位数（第25 - 75四分位数间距）179（158 - 285）cmH₂O·秒·分钟降至无创通气期间的91至111，面罩之间无差异（p = 0.84）。在动脉血气和呼吸模式方面观察到的差异很少。口含器的漏气和患者与呼吸机不同步情况更严重，大多数患者认为该接口的舒适度较差。
面罩的内部容积对气体交换、分钟通气量或患者努力没有明显的短期死腔效应，这表明，除口含器外，在临床实践中只要对通气设备参数进行调整，接口可能是可互换的。
