OBJECTIVETo assess the significance of stroke volume variation (SVV) and intrathoracic blood volume index (ITBI) on the responsiveness to volume loading in mechanically ventilated canine with hemorrhagic shock.

METHODSHemorrhagic shock canine model was established with the modified Wiggers' method. The heart rate (HR), mean artery pressure (MAP), central venous pressure (CVP), pulmonary artery wedge pressure (PAWP), intrathoracic blood volume index (ITBI) and stroke volume variation (SVV) were investigated by Swan-Ganz catheter or PiCCO monitor. Graded volume loading (VL) was performed. Successive responsive VLs were performed (increase in SV > 5% after VL) until continuous change in SV < 5% (unresponsive) was reached.

RESULTSFourteen canines were studied and a total of 134 VLs were performed. In 94 VLs, an increase in SV of more than 5% was reached. In the other 40 VLs, increase in SV was less than 5%. The change of HR, MAP, ITBI, SVV in responsive were more than those of unresponsive after VL. The change of CVP, PAWP in responsive were less than those of unresponsive. Significant correlation was found between DeltaSV after VL and the baseline values of ITBI, SVV. No correlation was found between DeltaSV and HR, MAP, CVP, PAWP. Significant correlations were also found between DeltaSV and DeltaCVP, DeltaPAWP, DeltaITBI, DeltaSVV after fluid loading. No correlation was found between DeltaSV and DeltaHR, DeltaMAP. By using receiver operating characteristic analysis, the area under the curve were 0.872 for SVV and 0.689 for ITBI, more than those of HR, MAP, CVP, PAWP statistically. As SVV value of 9.5% or more will predict an increase in the SV of at least 5% in response to a VL with a sensitivity of 92.6% and a specificity of 82.5%.

CONCLUSIONSSVV and ITBI were more useful indicators than CVP and PAWP on the assessment of responsiveness to volume loading. SVV as a functional preload parameter and for on-line monitoring may help to improve the hemodynamic management.

Animals ; Blood Volume ; physiology ; Blood Volume Determination ; methods ; Dogs ; Female ; Male ; Shock, Hemorrhagic ; diagnosis ; physiopathology ; Stroke Volume ; physiology

OBJECTIVETo study the bloody flow mode and the perfusion feature of solitary pulmonary nodules (SPN) on 64 multi-slice CT, and to evaluate the diagnostic value of combined scores in SPN.

METHODSFifty-two patients with SPN proved by pathology or follow-up underwent dynamic enhancement CT. Perfusion characteristics, including permeability (P), blood flow, blood volume, patlak blood volume, patlak R square (PRS), patlak residual, peak enhancement, perfusion curve, and false color image were analyzed by the body perfusion software. Perfusion characteristics were compared between benign and malignant nodules. Combined scores composed of significant difference observed parameters were used to differentiate benign or malignant SPN.

RESULTSThere were significant differences in the enhancement values at 20, 22, 24, 25, 26, 28, 30, and 34s, PRS, I or II type perfusion curve, and marginal uncomplete enhancement or patchy complete enhancement at 34s between benign and malignant SPN. With the multi-variant combined score > 0.5 as the threshold value to differentiate benign and malignant SPN, its sensitivity and specificity was 94.3% and 41.2%, respectively.

CONCLUSIONThe combined scores of 64 multi-slice CT can help differentiate the benign or malignant SPN.

Blood Volume ; Blood Volume Determination ; Hemodynamics ; Humans ; Lung Neoplasms ; blood supply ; diagnostic imaging ; physiopathology ; Permeability ; Solitary Pulmonary Nodule ; blood supply ; diagnostic imaging ; physiopathology ; Tomography, X-Ray Computed