Betbesé A J, Pérez M, Bak E, Ballús J, Net A, Mancebo J
Servei de Medicina Intensiva, Hospital de la Santa Creu I Sant Pau, Universitat Autònoma de Barcelona.
Med Clin (Barc). 1996 Jul 6;107(6):201-6.
To analyze the effects on gas exchange and hemodynamics of nitric oxide inhalation in patients with acute respiratory distress syndrome.
Prospective study including 16 acute respiratory distress syndrome patients. We analyzed the acute and short-term (5 days) effects of inhaling 5 parts per million (ppm) nitric oxide on gas exchange and hemodynamics.
After nitric oxide inhalation, PaO2/FiO2 ratio changed from 81 +/- 25 to 126 +/- 57 mmHg (p = 0.0001), mean pulmonary artery pressure decreased from 30.1 +/- 8.2 to 27.3 +/- 6.6 mmHg (p = 0.002), intrapulmonary shunt decreased from 44.6 +/- 11% to 34.1 +/- 7.9% (p = 0.002) and cardiac index did not change. Thirteen out of 16 patients (81.2%) presented at least a 20% improvement in PaO2/FiO2 ratio. In the 10 patients treated over 5 consecutive days, we observed that those who improved (increase in PaO2/FiO2 ratio higher than 20% after inhaling 5 ppm nitric oxide) showed a lower cardiac index, a higher mean pulmonary artery pressure and a higher pulmonary vascular resistance index than those who did not: Cl 3.9 +/- 0.81 vs 4.9 +/- 0.81 l/min/m2 (p < 0.001), mean pulmonary artery pressure 32.4 +/- 7 vs 25.3 +/- 4.2 mmHg (p = 0.001), and pulmonary vascular resistance index 421 +/- 199 vs 241 +/- 106 dyn.s.cm5/m2 (p = 0.003). Mean levels of methemoglobin were 1.1 +/- 0.24% (range: 0.4-1.6%), and NO2 concentration was always lower than 100 parts per billion.
Low doses of inhaled nitric oxide induce a selective pulmonary vasodilatation and significant improvement of oxygenation in the majority of acute respiratory distress syndrome patients, although those with a hyperkinetic hemodynamic status are less likely to improve the oxygenation. These effects are maintained for at least 5 days. We did not observe rebound effects.
分析吸入一氧化氮对急性呼吸窘迫综合征患者气体交换和血流动力学的影响。
前瞻性研究纳入16例急性呼吸窘迫综合征患者。我们分析了吸入百万分之五（ppm）一氧化氮对气体交换和血流动力学的急性及短期（5天）影响。
吸入一氧化氮后，氧合指数（PaO2/FiO2）从81±25 mmHg变为126±57 mmHg（p = 0.0001），平均肺动脉压从30.1±8.2 mmHg降至27.3±6.6 mmHg（p = 0.002），肺内分流从44.6±11%降至34.1±7.9%（p = 0.002），而心脏指数未改变。16例患者中有13例（81.2%）的氧合指数至少提高了20%。在连续治疗5天的10例患者中，我们观察到，吸入5 ppm一氧化氮后氧合指数改善（提高超过20%）的患者，其心脏指数较低，平均肺动脉压和肺血管阻力指数较高，与未改善的患者相比：心脏指数3.9±0.81 vs 4.9±0.81 l/min/m2（p < 0.001），平均肺动脉压32.4±7 vs 25.3±4.2 mmHg（p = 0.001），肺血管阻力指数421±199 vs 241±106 dyn.s.cm5/m2（p = 0.003）。高铁血红蛋白平均水平为1.1±0.24%（范围：0.4 - 1.6%），二氧化氮浓度始终低于十亿分之一百。
低剂量吸入一氧化氮可引起选择性肺血管扩张，并使大多数急性呼吸窘迫综合征患者的氧合显著改善，尽管血流动力学处于高动力状态的患者改善氧合的可能性较小。这些效应至少维持5天。我们未观察到反跳效应。
