Collie D D, Watt N J, Warren P M, Begara I, Luján L
Royal (Dick) School of Veterinary Studies, Veterinary Field Station, Roslin, Midlothian, UK.
Respir Physiol. 1994 Mar;95(3):239-47. doi: 10.1016/0034-5687(94)90087-6.
Static pressure-volume curves were generated from data obtained from 18 normal anaesthetized adult sheep. Lung volumes were determined by helium dilution. An exponential curve of the form V = Vmax - Ae-KP was fitted to the pressure-volume data from each sheep where P is the static recoil pressure, Vmax represents the volume asymptote, A is the difference between Vmax and the intercept on the volume axis and K defines the slope and hence the shape of the P-V curve. Quality of fit of the data was assessed visually, by means of a sign test and a runs test and by the coefficient of determination (r2). Exponential equations were found to adequately describe the shape of the pressure-volume curve in sheep. The exponent K was not correlated with effective alveolar volume (VAeff) (rs = 0.183; P > 0.05). Static lung compliance was determined over a volume range from the end-expiratory level (VEEL) to VEEL plus 400 ml. Measurements of static lung compliance were significantly correlated with measurements of effective alveolar volume (VAeff) (rs = 0.505; P < 0.025). In the ovine, the exponent K, an index of distensibility, is independent of lung volume and offers a means of assessing lung distensibility in this species.
静态压力-容积曲线由18只正常麻醉成年绵羊的数据生成。肺容积通过氦稀释法测定。将V = Vmax - Ae-KP形式的指数曲线拟合到每只绵羊的压力-容积数据，其中P为静态回缩压力，Vmax代表容积渐近线，A是Vmax与容积轴截距之间的差值，K定义斜率，从而确定P-V曲线的形状。通过目视评估、符号检验、游程检验以及决定系数（r2）来评估数据的拟合质量。发现指数方程能够充分描述绵羊压力-容积曲线的形状。指数K与有效肺泡容积（VAeff）不相关（rs = 0.183；P > 0.05）。在从呼气末水平（VEEL）到VEEL加400毫升的容积范围内测定静态肺顺应性。静态肺顺应性测量值与有效肺泡容积（VAeff）测量值显著相关（rs = 0.505；P < 0.025）。在绵羊中，指数K作为扩张性指标，与肺容积无关，为评估该物种的肺扩张性提供了一种方法。
