Lajos Bogar

Increased blood viscosity has not been associated with mortality risk in coronary heart disease (CHD). We aimed to investigate the predictive power of hematocrit per blood viscosity (Hct/BV) ratio as a marker of rheological oxygen carrying capacity of the blood to assess mortality risk of CHD. Elective coronary angiography was performed and CHD was proved in 109 patients in 1996 and 1997. In 78 cases (72%) complete follow up information was obtained in February 2006. During the follow up time (mean 8.9 years) 10 patients died due to cardiac cause (group C). Two patients died due to non-cardiac cause and 66 were still alive at the end of the follow up period (group NC, n=68). Mean hematocrit per blood viscosity (Hct/BV) ratio was significantly lower in group C comparing to NC (87+/-5; 93+/-9 Pa(-1)s(-1), SD, respectively, p=0.022). Other factors (body mass index, serum cholesterol, fibrinogen, hematocrit, plasma and blood viscosity, cardiac index, left ventricular ejection fraction) provided no statistical differences. Kaplan-Meier survival analysis showed only the impact of fibrinogen and Hct/BV ratio on cardiac mortality (p=0.029 and 0.009, respectively). Receiver operating characteristic curves proved only Hct/BV ratio to be able to differentiate between groups (area under curve: 0.716, p=0.028). Hct/BV ratio showed significant negative correlation with the frequency of hospital admissions (r=-0.377, p=0.03). Low Hct/BV ratio can be regarded as a risk factor of cardiac death in CHD.

Introduction: Postoperative care after oesophageal tumour resection holds a high risk of respiratory complications. We therefore aimed to determine the value of systemic inflammatory markers in predicting arterial hypoxaemia as the earliest sign of developing lung injury after oesophageal tumour resection. Methods: In a prospective observational study, 33 consecutive patients were observed for three days (T1–T3) after admission (T0) to an intensive care unit following oesophageal tumour resection. The daily highest values of the heart rate, axillary temperature, leukocyte count and PaCO₂ were recorded. Serum C-reactive protein and procalcitonin concentrations and the leukocyte antisedimentation rate (LAR) were determined at T1 and T2. Respiratory function was monitored 6-hourly measurement of the PaO₂/FIO₂ ratio, and the lowest value was recorded at T3. Patients were categorised as normoxaemic or hypoxaemic using the cutoff value of 300 mmHg for PaO₂/FIO₂. Results: Seventeen out of 33 patients were classified as hypoxaemic and 16 patients as normoxaemic at T3. Increases of temperature at T0 and of the procalcitonin and LAR values at T2 were predictive of hypoxaemia at T3 (P < 0.05, P < 0.01 and P < 0.001, respectively). The area under the receiver-operating characteristic curve was 0.65 for the temperature at T0, which was significantly lower than that for the procalcitonin level at T2 (0.83; 95% confidence interval, 0.69–0.97; P < 0.01) and that for LAR at T2 (0.89; 95% confidence interval, 0.77–1.00; P < 0.001). Conclusion: These results suggest that an elevated LAR (>15%) and an elevated procalcitonin concentration (>2.5 ng/ml) measured on the second postoperative day can predict next-day arterial hypoxaemia (PaO₂/FIO₂ < 300 mmHg) after oesophageal tumour resection.

Background:Early detection of blood stream infection can be lifesaving, but the results of blood cultures are not usually available before 24 hours after blood sampling. An earlier indication would lead to the initiation of immediate and adequate antibiotic treatment with obvious advantages for the patient.Objective:To evaluate the ability of leucocyte count, serum procalcitonin (PCT) concentration, erythrocyte sedimentation rate (ESR), and leucocyte antisedimentation rate (LAR) in predicting the blood culture results in critical care patients.Methods:39 consecutive patients with their first febrile episode were investigated prospectively. LAR was determined as the percentage of leucocytes crossing the midline of a blood column upward during one hour of gravity sedimentation. The relevance of the different variables was estimated by likelihood ratio tests and area under receiver operating characteristic curves (AUC).Results:23 patients had positive blood culture results and 16 negative. LAR was significantly higher in bacteraemic patients than in non-bacteraemic patients (p = 0.001), but leucocyte count, ESR and PCT level failed to show significant differences. Leucocyte count, PCT, and ESR yielded low discriminative values with the AUCs of 0.66, 0.64, and 0.52, respectively. LAR provided a likelihood ratio of 3.6 and an AUC of 0.80 (95% confidence interval, 0.64 to 0.95) (p = 0.002).Conclusions:The simple LAR test can predict blood culture results and support urgent treatment decisions in critical care patients in their first febrile episode.

Leukocyte function tests are suitable for monitoring the severity of chronic inflammatory and acute infectious diseases. The tests usually require time consuming leukocyte separation techniques while the original character of leukocytes can substantially alter. In contrast, we noted that gravity sedimentation properties of leukocytes is simple to measure and it also reflects non-specific inflammatory reactions of leukocytes. Our novel test is named leukocyte antisedimentation rate (LAR) which is measured by leukocyte counting in the upper (U) and lower (L) half of the sedimentation blood column after one-hour gravity sedimentation of the whole blood. The formula LAR=100.(U-L)/(U+L) is used to calculate the percentage of leukocytes crosses the middle line of sedimentation blood column upward during one-hour sedimentation (normal range<15%, inter-assay coefficient of variation<5%). In this study we found that in vitro pre-treatment of septic patients' blood samples with protamine, lidocaine and prednisolone decreased leukocyte antisedimentation rate in a concentration dependent manner without effecting erythrocyte sedimentation rate. Leukocyte adherence was measured by the retention rate of leukocytes in a nylon fibre column. There was a significant positive correlation between leukocyte antisedimentation rate and leukocyte adherence (p<0.01), hematocrit (p<0.05), erythrocyte sedimentation rate (p<0.05) when blood samples of 35 healthy individuals were analysed. We concluded that leukocyte antisedimentation rate in septic patients is significantly elevated comparing to healthy controls and as a bedside test it can reflect leukocyte involvement in infections. In vitro protamine, lidocaine and prednisolone pre-treatment of septic patients' blood samples indicates that leukocyte antisedimentation process is partially independent from the ongoing erythrocyte sedimentation.

Large-scale epidemiological studies have demonstrated that both anaemia and polycytaemia are independent cardiovascular risk factors. This was substantiated by the Framingham study, which demonstrated a U-shaped relation between haemoglobin concentration and mortality. It was previously noted that delineating the corresponding haematocrit/blood viscosity ratios in the function of haematocrit provided a distribution of an inverted U-shaped curve. The peak appeared physiologically important because it denotes a healthy balance between a relatively high oxygen binding capacity and a moderately low blood viscosity. It was the aim of this study to examine the mathematical relationship between the haematocrit and haematocrit/blood viscosity ratio.In a retrospective study, the haemorheological data of 32 healthy controls, 52 outpatients with hyperlipidaemia and 120 outpatients with Raynaud's disease were analyzed. Whole blood viscosity was measured with Hevimet 40 capillary viscometer at 37.0 degrees C and at shear rates of 10 s(-1), 90 s(-1) and 200 s(-1).Haematocrit/blood viscosity ratios in the function of haematocrit values showed a Gaussian association in the healthy subjects, hyperlipidaemic and Raynaud's disease outpatient groups. Peak values (i.e. the rheologically optimal haematocrit) were shear-rate and group dependent and were found at 44.3%, 43.5% and 38.3% in controls, hyperlipidaemic and Raynaud's disease patients, respectively, at a shear rate of 90 s(-1).This is one of the first reports in which a theoretically optimal haematocrit value was determined using the haematocrit/blood viscosity ratio. Further studies are needed to examine the potential clinical usefulness of this approach.

A number of clinical studies have demonstrated significant positive correlation between the severity of arterial hypertension (AHT) and whole blood viscosity. Red blood cell aggregation has also been associated with AHT especially in the severe form of the disease. The main possible cause of increased red blood cell aggregation is fibrinogen which can be found in a significantly higher concentration in patients with AHT than in healthy controls. On the other hand, blood pressure reduction with angiotensin-converting-enzyme inhibitors, calcium-channel-blocking agents, beta or alpha-receptor blocking drugs leads to a significant improvement of blood rheology. It can be presumed that abnormal hemorheology and AHT are not directly linked but they share the same inductive genetic and/or environmental factors like obesity, chronic mental stress, physical inactivity and cigarette smoking. Regarding this hypothesis, the appropriate question is not whether hemorheological factors are causes or results of AHT but what their common origins are. Further studies are needed to clarify this hypothetical link between hemorheology and AHT.

Whole blood gravity sedimentation technique can be modified for studying leukocyte sedimentation properties. Previously, we demonstrated that the displacement rate of leukocytes was associated with activation of leukocytes during traditional gravity sedimentation of the whole blood. The plasma flow as well as the difference between the specific gravity of leukocytes and plasma propel the leukocytes upward in the sedimentation tube while the erythrocyte aggregates are descending. The leukocyte ascension rate can be described as the increment of leukocyte concentration in the upper half section of the blood column after one-hour sedimentation. The aim of the present study was to characterize the ascending and non-ascending leukocytes using a flow cytometric technique. Venous blood samples were taken from 8 healthy controls and 8 septic patients after major thoracic or abdominal surgical procedures. The upper and lower halves sections of venous blood column were separately removed from the sedimentation tube after one hour gravity sedimentation. Using flow cytometry, the leukocyte subsets were identified by their CD45 density and side scatter parameters followed by characterization of their cellular size and cytoplasmic granularity. The size indices of septic patients' ascending polymorphonuclear leukocytes (PMNs) were significantly lower than that of the non-ascending ones (253 +/- 22 versus 387 +/- 12 (SEM), p < 0.002) or the ascending PMN fraction taken from healthy individuals (382 +/- 28, p < 0.005). Septic patients' ascending PMNs presented significantly lower cytoplasmic granularity indices compared to non-ascending (447 +/- 23 versus 538 +/- 18, p < 0.05) or healthy ascending PMNs (539 +/- 20, p < 0.05). The cellular size and cytoplasmic granularity indices of heavy and light monocytes as well as lymphocytes were similar in both groups. It can be assumed that venous blood samples of septic patients contain significantly smaller PMNs with less cytoplasmic granularity than healthy control cells.

During ischaemia, the glycolytic pathway (Embden-Meyerhof) is up regulated in an attempt to produce ATP anaerobically. However, this is short-lived due to negative feedback on the key glycolytic enzyme phosphofructokinase by accumulating lactate. Fructose-1,6-diphosphate (FDP), a high energy intermediary metabolite of this pathway, is unique in that is enters glycolysis distal to this inhibitory site. Exogenously administered FDP should therefore theoretically yield ATP independent of lactate accumulation and thereby ameliorate ischaemic injury. Clinical benefit has been shown in coronary artery bypass grafting (CABG) surgery, congestive cardiac failure and adult respiratory distress syndrome. Ischaemia-reperfusion injury induced by cardiopulmonary bypass (CPB) presents clinically as an impairment of myocardial function in the postoperative period. At a cellular level this reflects myocardial metabolic changes and nucleotide degradation (directly linked to high energy phosphate turnover). Quantification of myocardial nucleotide catabolite release therefore provides useful information regarding intermediary metabolism and cytoprotection conferred to myocardial (inosine, uridine) and endothelial (hypoxanthine) tissue. The authors investigated the myocardial cytoprotective effects of FDP in 16 patients scheduled for elective CABG surgery. Aortic and coronary sinus blood were collected directly into liquid nitrogen and analysed by high performance liquid chromatography prior to CPB and at different time points after reperfusion. FDP was administered intravenously in 8 patients and 5% dextrose was administered in 8 other patients. Analysis of transmyocardial (coronary sinus-aortic) nucleotide metabolite levels showed increased release of inosine, hypoxanthine and uridine in both the FDP and the control groups following reperfusion. However, compared to baseline (pre-aortic clamping) values, hypoxanthine and inosine concentrations were significantly elevated at 0, 1, 5 and 10 minutes following reperfusion in the control group. This was in contrast to earlier recovery to baseline levels (after 5 minutes of reperfusion) in the FDP group. Furthermore, when compared to control group, the hypoxanthine and inosine concentrations were significantly decreased by FDP treatment. Uridine concentrations were significantly elevated at 1 and 5 minutes in the control group and no significant change was observed in the FDP group. In conclusion, these data suggest that FDP, through an intermediary metabolic effect, may contribute to myocardial and endothelial cytoprotection during the ischaemic insult of cardiac surgery.