Hnatiuk O W, Moores L K, Thompson J C, Jones M D
Pulmonary and Critical Care Medicine Service, Walter Reed Army Medical Center, Washington, DC 20307-5001, USA.
Crit Care Med. 1998 Jun;26(6):1032-5. doi: 10.1097/00003246-199806000-00022.
Nonrebreather face masks (NRM) are frequently used in patients with respiratory distress and profound hypoxemia. A simpler modification to the partial rebreather face mask, using only two pieces of respiratory tubing or "tusks," has also been shown to increase FiO2 compared with the NRM in five normal subjects. Clinically, we have observed this modification to further increase PaO2 in critically ill patients already using the NRM in the intensive care unit. This study was designed to compare the Tusk mask with the NRM in both a larger group of normal subjects and in patients with underlying lung disease.
Prospective, randomized, crossover study.
A university teaching hospital and tertiary care referral center.
Sixteen normal subjects (11 male and 5 female; age 30.4+/-6.8 [SD] yrs) and seven patients with interstitial lung disease (ILD) (3 male and 4 female; age 68.1+/-11.9 yrs).
Subjects and patients served as their own controls and were randomized to wear either the NRM or Tusk mask for a 30-min period. After a 60-min washout period, the other mask was applied.
Arterial blood gas measurements were performed immediately before and at the end of each 30-min test period. Respiratory synchronization during the study period was achieved, using a metronome. In the normal subjects, PaO2 using the NRM and Tusk masks increased 290.0+/-57.1 torr (38.6+/-7.6 kPa) and 330.0+/-68.9 torr (44.0 +/-9.2 kPa), respectively (p=.032). PaO2 increased 293.4+/-38.0 torr (39.1+/-5.1 kPa) with the NRM and 378.4+/-61.7 torr (50.4+/-8.2 kPa) with the tusk mask (p=.001) in the patients with ILD. There was no statistically significant change seen in mean PaCO2 with either mask in either group. The mean PaO2 returned to within 6% of baseline in both groups after the washout period.
Both normal subjects and patients with compromised pulmonary function achieved a higher PaO2 using a Tusk mask than when using the conventional NRM, at the same oxygen flow rate. Patients with hypoxemia may obtain lifesaving benefit from the additional concentration of oxygen delivered via the Tusk mask.
非重复呼吸面罩（NRM）常用于呼吸窘迫和严重低氧血症患者。对部分重复呼吸面罩进行一种更简单的改良，仅使用两根呼吸管或“獠牙管”，在5名正常受试者中也已显示与NRM相比可提高吸氧浓度（FiO2）。临床上，我们观察到这种改良能进一步提高重症监护病房中已使用NRM的危重病患者的动脉血氧分压（PaO2）。本研究旨在比较在更多正常受试者和患有基础肺部疾病的患者中，獠牙管面罩与NRM的效果。
前瞻性、随机、交叉研究。
一所大学教学医院和三级医疗转诊中心。
16名正常受试者（11名男性和5名女性；年龄30.4±6.8[标准差]岁）和7名间质性肺疾病（ILD）患者（3名男性和4名女性；年龄68.1±11.9岁）。
受试者和患者作为自身对照，随机佩戴NRM或獠牙管面罩30分钟。经过60分钟的洗脱期后，佩戴另一种面罩。
在每个30分钟测试期开始前和结束时立即进行动脉血气测量。在研究期间使用节拍器实现呼吸同步。在正常受试者中，使用NRM和獠牙管面罩时的PaO2分别增加290.0±57.1托（38.6±7.6千帕）和330.0±68.9托（44.0±9.2千帕）（p = 0.032）。在ILD患者中，使用NRM时PaO2增加293.4±38.0托（39.1±5.1千帕），使用獠牙管面罩时增加378.4±61.7托（50.4±8.2千帕）（p = 0.001）。两组中使用任何一种面罩时平均二氧化碳分压（PaCO2）均无统计学显著变化。洗脱期后两组的平均PaO2均恢复到基线的6%以内。
在相同氧流量下，正常受试者和肺功能受损患者使用獠牙管面罩时的PaO2均高于使用传统NRM时。低氧血症患者可能从通过獠牙管面罩输送的额外氧气浓度中获得救命益处。
