Effect of increased intraabdominal pressure and decompressive laparotomy on aerated lung volume distribution
周建仓1 徐秋萍1 潘孔寒1 毛晨1 金重午1
Sir Run Run Shaw Hospital
Aim: To evaluayte the effect of increased intraabdominal pressure (IAP) and decompressive laparotomy (DL) on aerated lung volume distribution.
Methods: We retrospectively analyzed serial whole-lung computed tomography scans of 16 patients with increased IAP between July 2006 and July 2008 and compared to simultaneous control.
Results: The IAP increased from 12.1±2.3 mmHg on admission to 25.2±3.6 mmHg (P<0.01) before decompression and decreased to 14.7±2.8 mmHg after DL. Mean admission to DL hours and length of ICU stay were 26 hours and 16.2 days respectively. Percentage of normally aerated lung volume on admission was significantly lower than control (P<0.01). Prior to decompression, total lung volume and percentage of normally aerated lung volume decreased significantly compared to control (P<0.01), whereas volume and percentage of nonaerated lung increased significantly (P<0.01). Peak inspiratory pressure, partial pressure of carbon dioxide in arterial blood and central venous pressure elevated while PaO2/FiO2 decreased significantly before DL. Cranial displacement of the diaphragm about 1.8 cm was observed before decompression. The sagittal diameter of the lung at Th6 level increased significantly compared to control and on admission (P<0.01). After DL, the volume and percentage of nonaerated lung decreased significantly while the percentage of normally aerated lung volume increased significantly (P<0.01).
Conclusions: increased IAP decreases total lung volume while increases nonaerated lung volume measured by computed tomography. DL is associated with a relief of these changes.
