Arterial CO2 partial pressure affects diaphragmatic function.
Arterial CO2 partial pressure affects diaphragmatic function.
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动脉二氧化碳分压影响膈肌功能。
DOI：
10.1152/jappl.1985.58.3.823
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Roussos,C
中科院分区：
文献类型：
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作者：
Schnader,JY;Juan,G;Howell,S;Fitzgerald,R;Roussos,C
这项研究的目的是在活体制剂中检测二氧化碳分压对横隔肌收缩能力的剧烈变化。石膏模型贴合在六只开胸狗的腹部，将腹部内容物向右移动。对这一非常固定的负荷的横隔膜收缩对膈神经刺激(1、20、50和80赫兹的最大电压以上)或在自发吸气努力时的反应几乎是等长的(准等长的)。腹壁球囊测得的跨膈压(PDI)作为衡量横隔肌收缩能力的指标。过度换气可降低动脉血二氧化碳分压(PaCO2)，增加PICO2可使动脉血二氧化碳分压(PaCO2)升高。在范围I(PaCO_2=0-19 Torr)和II(PaCO_2=20-34 Torr)中，对1、20、50和80 Hz刺激的PDI值与对照组(范围III；PaCO_2=35-45 Torr)的PDI值无统计学差异。在IV范围内(PaCO2=46-70Torr)，20、50和80赫兹刺激的PDI值显著低于对照组。在V区(PaCO_2=71-90托)、VI区(PaCO_2=91-101托)和VII区(PaCO_2大于或等于102Torr)，在所有刺激频率下，PDI值均显著小于区IV。在4只狗的自发吸气过程中，测量的综合横隔膜肌电(EDI)与PDI相关。随着PaCO2的升高(范围III至VII)，在最大EDI的25、50、75、100%处观察到的PDI值显著低于范围III的PDI值。
The purpose of this study was to examine in an in vivo preparation acute variations of PCO2 on diaphragmatic contractility. Plaster casts were snugly fit around the abdomen of six open-chested dogs, moving the abdominal contents rostrally. Diaphragmatic contractions against this very fixed load in response to phrenic nerve stimulation (supramaximal voltage at 1, 20, 50, and 80 Hz) or during spontaneous inspiratory efforts were virtually isometric (quasi-isometric). Transdiaphragmatic pressure (Pdi) measured by an abdominal balloon was used as an index of diaphragmatic contractility. Arterial PCO2 (PaCO2) was reduced by hyperventilation and raised by increasing PICO2. Pdi values in response to stimulation at 1, 20, 50, and 80 Hz in ranges I (PaCO2 = 0–19 Torr) and II (PaCO2 = 20–34 Torr) did not differ statistically from the control Pdi values (range III; PaCO2 = 35–45 Torr). In range IV (PaCO2 = 46–70 Torr) Pdi values for stimulations of 20, 50, and 80 Hz were significantly lower than control. In range V (PaCO2 = 71–90 Torr), VI (PaCO2 = 91–101 Torr), and VII (PaCO2 greater than or equal to 102 Torr) Pdi values were significantly less than those in range IV at all frequencies of stimulation. In the four dogs measured during spontaneous inspiratory efforts the integrated diaphragmatic electromyogram (Edi) was correlated with the Pdi. As PaCO2 rose (range III to VII), the Pdi values observed at 25, 50, 75, 100% of the maximum Edi (of range III) were significantly lower than the Pdi value of range III.(