Comparison of cardiac output and blood volumes in intrathoracic compartments measured by ultrasound dilution and transpulmonary thermodilution methods

Purpose

To compare cardiac output (CO) and blood volumes measured by COstatus^® (Transonic Systems Inc., NY, USA) versus PiCCO (Philips IntelliVue MP40 with PiCCO-technology module M3012A#10, Netherlands) in adult ICU patients.

Methods

This was a prospective single-center study. Each of the 30 patients studied received a 5-Fr Pulsiocath femoral arterial and a standard central venous catheter. Twenty ml of iced 5% dextrose solution was injected for PiCCO measurements. For COstatus measurements, an extracorporeal arteriovenous loop, with two sensors placed on it, was connected between the Pulsiocath femoral arterial and central venous catheters. Blood was circulated through this loop at 12 ml/min for 5–8 min using a pump. Twenty ml of warm saline was injected into the venous side for measurements. For each method, three injections were averaged for comparison.

Results

A good agreement for measured CO (range 3.65–16.3 l/min) with a percentage error of 20% was observed, with r = 0.95, bias = ?0.037 l/min. PiCCO’s global end-diastolic volume (GEDV) was 2.5 times larger than the analogous COstatus’s total end-diastolic volume (TEDV) [TEDV = 0.28 × GEDV + 176 ml]. PiCCO’s intrathoracic blood volume (ITBV) was larger than the analogous COstatus’s central blood volume (CBV) [CBV = 0.73 × (ITBV) +78 ml].

Conclusions

CO measured by COstatus was found to be equivalent and hence interchangeable with PiCCO in this study population. COstatus blood volumes were found to be within the expected physiological range whilst PiCCO blood volumes were significantly higher, which was also observed in other studies. Future studies using 3D echo/MRI are required to validate these blood volumes.     

Involvement of semicarbazide-sensitive amine oxidase-mediated deamination in lipopolysaccharide-induced pulmonary inflammation

Semicarbazide-sensitive amine oxidase (SSAO) resides on the vascular endothelium and smooth muscle cell surface and is capable of deaminating short chain aliphatic amines and producing toxic aldehydes and hydrogen peroxide. The enzyme, also known as a vascular adhesion protein-1, is involved in the inflammation process. This intriguing protein with dual functions is increased in the serum of diabetic and heart failure patients. In the present study we assessed the involvement of SSAO in a lipopolysaccharide-induced pulmonary inflammation model using transgenic mice that overexpress human vascular adhesion protein-1. Overexpression of SSAO activity increased the formation of protein-formaldehyde deposits in tissues. Lysine residues of proteins were the primary targets for cross-linkage with formaldehyde derived from deamination of methylamine. Lipo-polysaccharide-induced increases in inflammatory cells in the bronchoalveolar lavage (BAL) fluid were significantly higher in the transgenic than in the nontransgenic mice. BAL cell counts were also higher in the untreated transgenic than in nontransgenic mice. Blocking SSAO activity with a selective inhibitor significantly reduced the number of neutrophils as well as levels of macrophage inflammatory protein-1alpha, granulocyte colony-stimulating factor, tumor necrosis factor-alpha, and interleukin-6 in the BAL fluid. Inhalation of methylamine also increased BAL neutrophil counts. Together, these results suggest a role for SSAO-mediated deamination in pulmonary inflammation.     

The impact of combining educational program with the improving of infrastructure to diagnose on early detection of primary immunodeficiencies in children

Early detection of primary immunodeficiency diseases (PID) is vital for adequate prevention and management of PID infectious complications. The objective of this study was to evaluate the impact of a model combining physician education and public awareness with the infrastructure to diagnose PID to improve its early detection in children. Three approaches were combined and the results were followed from February 2017 to February 2019 in Ternopil region, Ukraine: the education of primary care physicians and other specialists on early PID detection using workshops, trainings, and targeted publications; organization of public events and media appearances to raise PID awareness; performing immunological testing for patients with suspected PID. Among the 150 individuals that were screened, PID was diagnosed in 19 patients (12.7%). The majority of diagnosed PID cases were combined immunodeficiency with associated or syndromic features, followed by antibody deficiencies. Patients referred by the specialist doctors had the highest percentage of confirmed PID compared with those referred by primary care physicians (p = 0.0273) and risk group patients (p = 0.0447). Among warning signs in patients with PID, two or more pneumonias within 1 year occurred most often (26.3%), followed by failure of an infant to gain weight or grow normally (21.1%). Among other signs of PID, dysmorphic features and microcephaly were the most prevalent (31.6%). In conclusion, a program combining physician education and public awareness with infrastructure needed to diagnose primary immunodeficiency diseases is an effective tool for early PID diagnosis. Physician education was a more effective tool compared with rising public awareness.

     

Protein cross-linkage induced by formaldehyde derived from semicarbazide-sensitive amine oxidase-mediated deamination of methylamine

Semicarbazide-sensitive amine oxidase (SSAO) catalyzes the conversion of methylamine to formaldehyde. This enzyme is located on the surface of the cytoplasmic membrane and in the cytosol of vascular endothelial cells, smooth muscle cells, and adipocytes. Increased SSAO activity has been found in patients with diabetes mellitus, chronic heart failure, and multiple types of cerebral infarcts and is associated with obesity. Increased SSAO-mediated deamination may contribute to protein deposition, the formation of plaques, and inflammation, and thus may be involved in the pathophysiology of chronic vascular and neurological disorders, such as diabetic complications, atherosclerosis, and Alzheimer's disease. In the present study, we demonstrate the induction of cross-linkage of formaldehyde with the lysine moiety of peptides and proteins. Formaldehyde-protein adducts were reduced with sodium cyanoborohydride, hydrolyzed in hydrochloric acid, and the amino acids in the hydrolysates were derivatized with fluorenylmethyl chloroformate and then identified with high-performance liquid chromatography. We further demonstrate that incubation of methylamine in the presence of SSAO-rich tissues, e.g., human brain meninges, results in formaldehyde-protein cross-linkage of particulate bound proteins as well as of soluble proteins. This cross-linkage can be completely blocked by a selective inhibitor of SSAO. Our data support the hypothesis that the SSAO-induced production of formaldehyde may be involved in the alteration of protein structure, which may subsequently cause protein deposition associated with chronic pathological disorders.     

Assessment of cardiac output and intrathoracic blood volume by means of transpulmonary thermodilution and ultrasound dilution: similarities and differences

The aim of the study is to compare results of the assessment of cardiac output and intrathoracic blood volume by two methods--transpulmonary (TTD) and ultrasound (UTD) thermodilution. MATERIALS AND METHODS: The prospective study included 58 patients (sepsis, septic shock, acute respiratory distress syndrome, intracranial haemorrhages), which underwent femoral artery catheterization with "Pulsiocath" 5Fr catheter (PICCO technology). For the means of ultrasound the catheter was connected to the central venous catheter by an arteriovenous loop. Sensors on arterial and venous ends of the loop registered the time and the volume of the indicator, blood properties and the ultrasound curve. Cooled (0 to 8 C) 5% glucose solution was used as an indicator for TTD, while heated (up to 37C) 0.9% NaCl solution was used as an indicator for the ultrasound. The cardiac output (CO) was measured by TTD and UTD, the global end diastolic volume (GEDV) by TTD, its analogue total end diastolic volume (TEDV) by UTD, intrathoracic blood volume (ITBV) by TTD and central blood volume (CBV) by UTD. 218 pairs of measurements were conducted. Oscillations of CO (TTD) were 2.76-16.3 l/min (8.6 +/- 2.48 l/min) and of CO (UTD)--2.92-18.1 l/min (8.72 +/- 2.65 l/min). There was a strong correlation between CO (TTD) and CO (UTD). The systematic mistake was 0.12 l/min, percentage based mistake--20.9%. ITBV correlated with CBV. There was a big systematic mistake found, which measured as much as 323 ml, the percentage based mistake was 36.5%. The correlation between GEDV and TEDV was (r = 0.70, p < 0.01). The TTD ejection fraction (23.2 +/- 5.6%) was lower (p < 0.01), than by UTD (57.8 +/- 15.2%). RESULTS: Both methods demonstrate close values of CO. GEDV was higher than TEDV and physiological heart volume. The absolute values of GEDV and ITBV measured by TTD are higher than the actual ones, although they reflect the changes of blood volume and can be used as dynamic preload parameters.