Biomedical subjects

M Matĕjovic

Publications and source records attributed to M Matĕjovic.

12 recordsLinked to original sources

PubMed2003

[Acute kidney failure in critically ill patients and its prevention].

Acute renal failure often complicates the course of critically illness and can contribute to high morbidity and mortality. In most cases acute renal failure represents a part of the multiple organ dysfunction syndrome and it is usually related to the ischemic and/or toxic injury of tubular cells (acute tubular necrosis, ATN). The presented paper reviews the mechanisms involved in this two types of tubular cells injury. It analyzes the measures of kidney protection during critical illness, which include optimization of systemic and intrarenal hemodynamics as well as avoidance of nephrotoxic drugs. It describes the most common nephrotoxic drugs and proposes principles of their safer use. Potential strategies to stimulate kidney function recovery are also discussed.

Acute Kidney Injury↗

PubMed2003

Enteral nutrition and hepatosplanchnic region in critically ill patients - friends or foes?

Enteral nutrition (EN) is a preferred way of feeding in critically ill patients unless obvious contraindications such as ileus or active gastrointestinal bleeding are present. Early enteral nutrition as compared to delayed EN or total parenteral nutrition decreases morbidity in postsurgical and trauma patients. The hepatosplanchnic region plays a pivotal role in the pathophysiology of sepsis and multiple organ dysfunction syndrome. The beneficial effects of EN on splanchnic perfusion and energy metabolism have been documented both in healthy volunteers and animal models of sepsis, hemorrhagic shock and burns. By contrast, EN may increase splanchnic metabolic demands, which in turn may lead to oxygen and/or energy demand/supply mismatch, especially when hyperemic response to EN is not preserved. Therefore, the timing of initiation and the dose of EN in patients with circulatory failure requiring vasoactive drugs are a matter of controversy. Interestingly, the results of recent clinical studies suggest that early enteral nutrition may not be harmful even in patients with circulatory compromise. Nevertheless, possible onset of serious complications, the non-occlusive bowel necrosis in particular, have to be kept in mind. Unfortunately, there is only a limited number of clinically applicable monitoring tools for the effects of enteral nutrition in critically ill patients.

Animals↗

PubMed2003

[Angiotropic lymphoma (intravascular lymphomatosis)--2 case reports].

Described are two cases of angiotropic lymphoma where eventually autopsy elucidated nonspecific neurologic symptoms. One patient suffering ambiguous encephalitic syndrome died three months later, the second one passed away after an unusually long three-year period of progressive dementia and cumulative motoric dysfunction. The autopsy disclosed pure intravascular malignant lymphoid aggregates (LCA, CD 20, Bcl 2-positive) in the brain and kidney of both patients. In the patients with the longer disease period, a dissemination to lung was also found. Definitive diagnosis was issued as a B cell type of angiotropic lymphoma. Skin, lymph nodes, spleen, and bone marrow were not affected in any case. The clinical differential diagnosis algorithm did not involve this rare etiology in these particular uncommon neurologic cases and even brain biopsy performed in both women did not recognize the substantiality of the disease.

Brain Neoplasms↗

PubMed2003

[Rhabdomyolysis--development, causes, sequelae and therapy].

Rhabdomyolysis is a syndrome characterized by striated muscle necrosis and the release of intracellular muscle constituents into the circulation. The severity of illness ranges from asymptomatic elevations of muscle enzymes in the serum to life-threatening cases associated with extreme enzyme elevations, electrolyte imbalances, and acute renal failure. This chapter reviews recent knowledge of pathophysiologic mechanisms leading to myocytes injury, diseases its causes, consequences and treatment options. Particular attention is focused on rhabdomyolysis in critically ill patients.

Humans↗

PubMed2002

[Fluid resuscitation in conditions with disorders of capillary permeability].

Fluid resuscitation remains a cornerstone in the treatment of various types of circulatory failure. Alterations in microvascular permeability are a hallmark of a number of inflammatory conditions including sepsis, septic shock, burns and the acute respiratory distress syndrome. As a result, the loss of plasma fluid into the interstitial space leads to hypovolaemia and tissue hypoperfusion. Administration of large volumes of fluids in often necessary to restore the nutritional blood flow to tissues. This strategy, however, involves the risk of interstitial edema formation, which in turn may further impair tissue oxygen distribution. The presented paper briefly reviews the principles of transvascular fluid exchange and the pathophysiology of capillary permeability. It discusses the ongoing controversy on the optimal way and the end points of volume replacement as well as the choice of fluid in conditions associated with capillary leakage.

Capillary Leak Syndrome↗

PubMed2002

[Gastrointestinal tract dysfunction in critical illness].

Until relatively recently, the gastrointestinal (GI) tract was considered a dormant, metabolically and immunologically inactive organ in critically illnesses. However, the GI tract provides a number of crucial functions that, in fact, may influence morbidity and mortality of many critically ill patients. Its large absorptive area provides a site for nutrient digestion and utilization and serves as an important barrier preventing the systemic absorption of intraluminal microbes and its toxic products. Moreover, the GI tract is the largest reservoir of lymphocytes in the body, which significantly contribute to the immune response of the critically ill patients. The gut dysfunction occurs frequently and early in the intensive care patients. Abnormal colonization, impaired intestinal epithelial barrier function and bacterial translocation represent the key components of gut failure implicating in the pathogenesis of sepsis and multiorgan dysfunction. This review summarizes recent insights into the role of the gut in critically ill patients with particular focus on 1) the basis of "gut-origin hypothesis", 2) pathophysiology of gut dysfunction, 3) monitoring of intestinal function, and 4) protective measures and novel therapeutic strategies.

Bacterial Translocation↗

PubMed2002

Continuous venovenous hemofiltration: effects on monocyte and lymphocyte immunophenotype in critically ill patients.

The aim of this study was to test the hypothesis that continuous venovenous hemofiltration (CVVH) increases HLA-DR expression on monocytes and T lymphocytes in critically ill patients. 24 septic (SP) and 10 non-septic (NSP) medical ICU patients with acute renal failure were studied prospectively. The ultrafiltration rate was 20-30 ml.kg(-1).h(-1). The total and differential white cell counts were measured and CD3+ lymphocyte count, HLA-DR expression on CD14+ monocytes and CD3+ lymphocytes were analysed by two-colour flow cytometry before, 4 and 24 h after CVVH initiation, respectively. CVVH did not influence leukocyte, granulocyte, total lymphocyte and CD3+ lymphocyte counts in both groups of patients. The percentage of HLA-DR+/CD14+ monocytes in SP revealed no changes, whereas it decreased after 4 h of CWH in NSP (p < 0.05). The percentage of HLA-DR+/CD3+ lymphocytes in SP decreased after 24 h (p < 0.05), whereas it remained unchanged in NSP. We conclude that CWH initiation is not associated with the increase of HLA-DR expression on CD14+ monocytes and T lymphocytes in critically ill patients with acute renal failure.

APACHE↗

PubMed2001

Effects of nicotinamide, an inhibitor of PARS activity, on gut and liver O2 exchange and energy metabolism during hyperdynamic porcine endotoxemia.

OBJECTIVE: To investigate the effects of nicotinamide (NIC), an inhibitor of poly(ADP-ribose) synthetase (PARS), on intestinal and liver perfusion, O2 kinetics, and energy metabolism over 24 h of hyperdynamic porcine endotoxemia. DESIGN: Prospective, randomized, controlled experimental study with repeated measures. SETTING: Animal laboratory in a university hospital. SUBJECTS: Sixteen pigs, divided into two groups: nine endotoxemic animals without therapy (CON); seven animals treated with NIC. INTERVENTIONS: Pigs were anesthetized, mechanically ventilated, and instrumented. Intravenous E. Coli LPS was continuously infused over 24 h concomitant with fluid resuscitation. After 12 h of endotoxemia continuous i.v. infusion of NIC (10 mg/kg per hour) was administered until the end of the experiment. MEASUREMENTS AND RESULTS: All animals developed hyperdynamic circulation with sustained increase in cardiac output and progressive fall in mean arterial pressure. NIC maintained blood pressure without affecting CO. Hepato-splanchnic macrocirculation was not modified by the treatment. Nevertheless, although NIC attenuated the progressive rise of ileal mucosal-arterial PCO2 gap, it failed to improve portal venous L/P ratio, a marker of the overall energy state of the portal venous drained viscera. Similarly, neither the increased hepatic venous L/P ratio nor the simultaneous drop in hepatic lactate uptake were influenced by NIC. CONCLUSIONS: Although NIC maintained hemodynamic stabilization during long-term endotoxemia, it was unable to improve LPS-induced deterioration of the hepato-splanchnic energy metabolism. More potent and selective PARS inhibitors are needed to elucidate the role of a PARS-dependent pathway in a clinically relevant models of sepsis.

Animals↗

PubMed2001

Impact of enteral feeding on gastric tonometry in healthy volunteers and critically ill patients.

BACKGROUND: Enteral feeding may interfere with gastric tonometry measurement. The effect of enteral nutrition on gastric tonometry has not been fully documented. METHODS: Seven healthy volunteers and nine stable intensive care unit (ICU) patients with poor tolerance of gastric feeding were investigated. Consecutive continuous postpyloric and gastric feeding, both at two different rates (40 and 100 ml. h-1, respectively), and an intragastric 200 ml nutrition bolus were studied. Gastric intramucosal PCO2 (PiCO2) was measured by air tonometry and in patients a gastric intramucosal-arterial PCO2 difference (PCO2 gap) was calculated. Hemodynamics and blood gases were also measured. RESULTS: In volunteers, PiCO2 remained stable during the postpyloric phase. During continuous gastric feeding PiCO2 did not change significantly, although in 4 volunteers PiCO2 increased >0.5 kPa. PiCO2 decreased significantly after gastric bolus from 6.9+/-0.4 to 6.1+/-0.5 kPa (P<0.05). Eight patients had an increased PCO2 gap (>1 kPa) at baseline (1.8+/-0.6 kPa). PCO2 gap changes during the whole study were not statistically significant. However, during the postpyloric phase (or immediately afterwards), the PCO2 gap increased by more than 0.5 kPa in 5 patients. After gastric bolus, a decrease in PCO2 gap >0.5 kPa was seen in 5 patients. CONCLUSION: In volunteers, postpyloric feeding does not interfere with gastric tonometry measurement and gastric bolus leads to a PiCO2 decrease. The impact of postpyloric and gastric feeding on gastric tonometry in ICU patients with compromised gut is variable.

Adolescent↗

PubMed2001

[Extravascular lung water in acute respiratory distress syndrome: pathophysiology, monitoring and therapeutic possibilities].

Excessive amount of extravascular lung water (EVLW) resulting from increased permeability of alveolo-capillary membrane is a pathophysiological hallmark of acute respiratory distress syndrome (ARDS). Increased EVLW produces hypoxemia by interference with gas exchange. During shock resuscitation, in disorders in which microvascular endothelial integrity is impaired, large volumes of intravenous fluids needed to restore tissue perfusion may also be associated with the risk of increased accumulation of EVLW. The presented paper briefly reviews the mechanisms involved in lung edema formation and describes current options to measure EVLW. In addition, it discusses clinical implications of EVLW measurement in intensive care setting with particular focus on transpulmonary indicator dilution technique.

Capillary Permeability↗

PubMed1999

[Acute respiratory distress syndrome].

Acute respiratory distress syndrome (ARDS) is the general term used for severe acute respiratory failure of diverse aetiology. It is associated with a high morbidity, mortality (50-70%), and financial costs. Regardless of aetiology, the basic pathogenesis of ARDS is a systemic inflammatory response leading to a diffuse inflammatory process that involves both lungs, thus causing diffuse alveolar and endothelial damage with increased pulmonary capillary permeability and excessive extravascular lung water accumulation. ARDS is commonly associated with sepsis and multiple organ failure. The clinical picture involves progressive hypoxaemia, radiographic evidence of pulmonary oedema, decreased lung compliance and pulmonary hypertension. Despite the scientific and technological progress in critical care medicine, there is no specific ARDS therapy available at the moment and its management remains supportive. Therapeutic goals include resolution of underlying conditions, maintenance of acceptable gas exchange and tissue oxygenation and prevention of iatrogenic lung injury. Many new specific therapeutic strategies have been developed, however, most of them require further scientific evaluation. The paper reviews definition, basic pathogenesis and pathophysiology of ARDS and discusses current concepts of therapeutic possibilities of ARDS.

Humans↗

PubMed1998

Continuous venovenous hemodiafiltration (CVVHDF) with citrate anticoagulation in the treatment of a patient with acute renal failure, hypercalcemia, and thrombocytopenia.

A 72-year-old patient with multiple myeloma was admitted to the intensive care unit because of hypercalcemic crisis and acute renal failure. After 7 days of comprehensive therapy including diuretics steroids, calcitonin, and intermittent hemodialysis (IHD) with low-calcium dialysate, calcium still reached high levels between IHD treatments and thrombocytopenia developed after chemotherapy. CVVHDF with calcium-free bicarbonate dialysate was started. Anticoagulation with 2.2% citrate was performed in order to chelate calcium, and thus treat the hypercalcemia, and to provide regional anticoagulation, and thus reduce the risk of bleeding due to thrombocytopenia. CVVHDF with citrate anticoagulation was continued for 6 days, and standard heparin anticoagulation was started when the hypercalcemia and thrombocytopenia abated.

Acute Kidney Injury↗