Kerbaul François, Rondelet Benoît, Motte Sophie, Fesler Pierre, Hubloue Ives, Ewalenko Patricia, Naeije Robert, Brimioulle Serge
Anesthesiology, La Timone Hospital, Marseille, France.
Anesthesiology. 2004 Dec;101(6):1357-62. doi: 10.1097/00000542-200412000-00016.
Halogenated anesthetics depress left ventricular function, but their effects on the right ventricle have been less well studied. Therefore, the authors studied the effects of isoflurane and desflurane on pulmonary arterial (PA) and right ventricular (RV) properties at baseline and in hypoxia.
Right ventricular and PA pressures were measured by micromanometer catheters, and PA flow was measured by an ultrasonic flow probe. PA mechanics were assessed by flow-pressure relations and by impedance spectra derived from flow and pressure waves. RV contractility was assessed by end-systolic elastance (Ees), RV afterload was assessed by effective PA elastance (Ea), and RV-PA coupling efficiency was assessed by the Ees:Ea ratio. Anesthetized dogs were randomly assigned to increasing concentrations (0.5, 1, and 1.5 times the minimum alveolar concentration) of isoflurane (n = 7) or desflurane (n = 7) in hyperoxia (fraction of inspired oxygen, 0.4) and hypoxia (fraction of inspired oxygen, 0.1).
Isoflurane and desflurane had similar effects. During hyperoxia, both anesthetics increased PA resistance and characteristic impedance, increased Ea (isoflurane, from 0.82 to 1.44 mmHg/ml; desflurane, from 0.86 to 1.47 mmHg/ml), decreased Ees (isoflurane, from 1.09 to 0.66 mmHg/ml; desflurane, from 1.10 to 0.72 mmHg/ml), and decreased Ees:Ea (isoflurane, from 1.48 to 0.52; desflurane, from 1.52 to 0.54) in a dose-dependent manner (all P < 0.05). Hypoxia increased PA resistance, did not affect characteristic impedance, increased afterload, and increased contractility. During hypoxia, isoflurane and desflurane had similar ventricular effects as during hyperoxia.
Isoflurane and desflurane markedly impair RV-PA coupling efficiency in dogs, during hyperoxia and hypoxia, both by increasing RV afterload and by decreasing RV contractility.
卤化麻醉药会抑制左心室功能，但它们对右心室的影响研究较少。因此，作者研究了异氟烷和地氟烷在基线状态及低氧情况下对肺动脉（PA）和右心室（RV）特性的影响。
通过微压计导管测量右心室和肺动脉压力，并用超声流量探头测量肺动脉血流量。通过流量-压力关系以及从流量和压力波得出的阻抗谱来评估肺动脉力学。通过收缩末期弹性（Ees）评估右心室收缩性，通过有效肺动脉弹性（Ea）评估右心室后负荷，通过Ees:Ea比值评估右心室-肺动脉耦合效率。将麻醉犬随机分为两组，分别给予在高氧（吸入氧分数为0.4）和低氧（吸入氧分数为0.1）情况下递增浓度（最小肺泡浓度的0.5、1和1.5倍）的异氟烷（n = 7）或地氟烷（n = 7）。
异氟烷和地氟烷具有相似的作用。在高氧期间，两种麻醉药均增加肺动脉阻力和特征阻抗，增加Ea（异氟烷，从0.82 mmHg/ml增至1.44 mmHg/ml；地氟烷，从0.86 mmHg/ml增至1.47 mmHg/ml），降低Ees（异氟烷，从1.09 mmHg/ml降至0.66 mmHg/ml；地氟烷，从1.10 mmHg/ml降至0.72 mmHg/ml），并以剂量依赖性方式降低Ees:Ea（异氟烷，从1.48降至0.52；地氟烷，从1.52降至0.54）（所有P < 0.05）。低氧增加肺动脉阻力，不影响特征阻抗，增加后负荷，并增加收缩性。在低氧期间，异氟烷和地氟烷对心室的作用与高氧期间相似。
在高氧和低氧情况下，异氟烷和地氟烷均通过增加右心室后负荷和降低右心室收缩性，显著损害犬的右心室-肺动脉耦合效率。
