scholarly journals Estimation of errors in determining intrathoracic blood volume using thermal dilution in pigs with acute lung injury and haemorrhage †

2004 ◽  
Vol 93 (4) ◽  
pp. 546-551 ◽  
Author(s):  
M. Nirmalan ◽  
M. Niranjan ◽  
T. Willard ◽  
J.D. Edwards ◽  
R.A. Little ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Blood Volume ◽  
Intrathoracic Blood Volume ◽  
Thermal Dilution

Estimation of Errors in Determining Intrathoracic Blood Volume Using the Single Transpulmonary Thermal Dilution Technique in Hypovolemic Shock

2005 ◽  
Vol 103 (4) ◽  
pp. 805-812 ◽  
Author(s):  
Mahesh Nirmalan ◽  
Terrance M. Willard ◽  
Dennis J. Edwards ◽  
Rod A. Little ◽  
Paul M. Dark
Keyword(s):  
Blood Volume ◽  
Hypovolemic Shock ◽  
Shock Group ◽  
Intrathoracic Blood Volume ◽  
Control Group ◽  
Regression Equations ◽  
Dilution Technique ◽  
Lung Water ◽  
Estimation Errors ◽  
Thermal Dilution

Background The transpulmonary thermal dilution technique has been widely adopted for monitoring cardiac preload and extravascular lung water in critically ill patients. This method assumes intrathoracic blood volume (ITBV) to be a fixed proportion of global end-diastolic volume (GEDV). This study determines the relation between GEDV and ITBV under normovolemic and hypovolemic conditions and quantifies the errors in estimating ITBV. Methods Nineteen pigs allocated to control (n = 9) and shock (n = 10) groups were studied. Shock was maintained for 60 min followed by volume resuscitation. The dual dye-thermal dilution technique was used to measure GEDV and ITBV (ITBVm) at baseline (time 0), shock phase (30 and 90 min), and after resuscitation (150 min). The regression equations estimated from paired GEDV and ITBVm measurements under normovolemic and hypovolemic conditions were used to estimate ITBV from the corresponding GEDV, and the estimation errors were quantified. A more simplified equation, used in a commercially available clinical monitor (ITBV = 1.25 x GEDV), was then used to estimate ITBV. Results The regression equation in the control group was ITBVm = 1.21 x GEDV + 99 (r = 0.89, P < 0.0001) and in the shock group at 30 and 90 min was ITBVm = 1.45 x GEDV + 0.6 (r = 0.95, P < 0.0001). The 95% confidence interval for the y-intercept was relatively wide, ranging from 31 to 168 and -47 to 49, respectively, for the two equations. The equation estimated in the control group led to overestimation of ITBV and a significant (P < 0.05) increase in errors in the shock group at 30 and 90 min. Errors in estimating ITBV using the simplified commercial algorithm were less than 15% under normovolemic and hypovolemic conditions. Conclusions The linear relation between GEDV and ITBV is maintained in hypovolemic shock. Even though the relation between GEDV and ITBV is influenced by circulatory volume and cardiac output, the mean errors in predicting ITBV were small and within clinically tolerable limits.

Effects of Intravascular Volume Replacement on Lung and Kidney Function and Damage in Nonseptic Experimental Lung Injury

2013 ◽  
Vol 118 (2) ◽  
pp. 395-408 ◽  
Author(s):  
Pedro L. Silva ◽  
Andreas Güldner ◽  
Christopher Uhlig ◽  
Nadja Carvalho ◽  
Alessandro Beda ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Kidney Function ◽  
Blood Volume ◽  
Kidney Damage ◽  
Volume Replacement ◽  
Intravascular Volume ◽  
Major Hemorrhage ◽  
Kidney Morphology ◽  
Lung And Kidney

Abstract Background: Intravascular volume replacement is often required in the presence of increased pulmonary capillary leakage, for example in patients with volutrauma with major hemorrhage. In the present study, the effects of Ringer’s acetate (RA), gelatin-polysuccinate (GEL), and a modern hydroxyethyl starch (HES, 6% 130/0.42) on lung and kidney function and damage were compared in a two-hit model of acute lung injury. The authors hypothesized that GEL and HES, compared to RA: (1) reduced lung histological damage, (2) impaired kidney morphology and function. Methods: Acute lung injury was induced in 30 anesthetized pigs by tidal volumes approximately 40 ml/kg, after saline lung lavage. Protective ventilation was initiated and approximately≈25% of estimated blood volume was drawn. Animals were randomly assigned to receive RA, GEL, or HES (n = 10/group) aimed at approximately 90% of intrathoracic blood volume before blood drainage. Results: Fluid volumes were higher with RA (2,250 ± 764 ml) than GEL (704 ± 159 ml) and HES (837 ± 82 ml) (P < 0.05). Compared to RA, HES reduced diffuse alveolar damage overall, and GEL in nondependent zones only. GEL and HES yielded lower wet-to-dry ratios compared to RA (6.5 ± 0.5 and 6.5 ± 0.6 vs. 7.9 ± 0.9, respectively, P < 0.05). HES and RA resulted in less kidney damage than GEL, but kidney function did not differ significantly among groups. Compared to GEL, HES yielded lower lung elastance (55 ± 12 vs. 45 ± 13 cm H2O/l, P < 0.05) and intra-abdominal pressure (15 ± 5 vs. 11 ± 4 cm 14;H2O, P < 0.05). Conclusions: In this model of acute lung injury, intravascular volume expansion after major hemorrhage with HES yielded less lung damage than RA and less kidney damage than GEL.

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