Ultrasound cardiac output monitoring in mechanically ventilated children.

AIM: To non-invasively identify the hemodynamic changes in critically ill children during the first 48 h following initiation of mechanical ventilation by the ultrasound cardiac output monitor (USCOM) method and compare the data in children with pulmonary and non-pulmonary pathology. MATERIALS AND METHODS: This was a prospective observational study to evaluate the influence of mechanical ventilation on hemodynamic changes and to describe hemodynamic profiles of mechanically ventilated children. A total of 56 children with respiratory failure were included in the present study. Ventilated patients are divided into two groups. Group A (n=36) includes patients with pulmonary pathology. Group B (n=20) consists of patients with extra pulmonary etiology of respiratory failure. Hemodynamic parameters (cardiac index and systemic vascular resistance index) were evaluated using ultrasound cardiac output monitoring (USCOM 1A) immediately following initiation of mechanical ventilation and again at 6, 12, and 48 h. Pharmacological circulatory support (inotropes, vasopressors, levosimendan and phosphodiesterase III inhibitors) was individually and continuously modified based on real-time hemodynamic parameters and optimal fluid balance. RESULTS: No significant differences in hemodynamic profiles were found between Group A and Group B. CONCLUSION: The protective strategy of mechanical ventilation was not associated with significant differences in hemodynamic profiles between children ventilated for pulmonary and non-pulmonary pathologies. CLINICAL SIGNIFICANCE: Hemodynamically unstable children ventilated for pulmonary pathology with the protective strategy of mechanical ventilation had a greater requirement for inotropic and combined inotropic and vasoactive circulatory support than children ventilated for non-pulmonary causes of respiratory failure.

Right Ventricular Pressure Overload and Pathophysiology of Growing Porcine Biomodel.

The primary objective was to create a clinically relevant model of right ventricular hypertension and to study right ventricular myocardial pathophysiology in growing organism. The secondary objective was to analyse the effect of oral enoximone (phosphodiesterase inhibitor) therapy on right ventricular haemodynamic parameters and myocardial changes in biomodel of right ventricular hypertension. The study included a total of 12 piglets of 42 days of age. Under general anaesthesia, pulmonary artery banding (PAB) was performed surgically to constrict the main pulmonary artery to about 70-80 % of its original dimension. The study presented two groups of animals labelled C (control animals with PAB; n = 8) and E (animals with PAB and oral administration of enoximone; n = 4). Direct pressure and echocardiographic measurements were taken during operation (time-1), and again at 40 days after surgery (time-2). The animals were killed, and tissue samples from the heart chambers were collected for quantitative morphological assessment. Statistical analysis was performed on all acquired data. At time-2, the median weight of animals doubled and the median systolic pressure gradient across the PAB increased (46.59 ± 15.87 mmHg vs. 20.29 ± 5.76 mmHg; p < 0.001). Changes in haemodynamic parameters were compatible with right ventricular diastolic dysfunction in all the animals. Apoptosis, tissue proliferation and fibrosis were identified in all the myocardial tissue samples. Right ventricular pressure overload leads to increased apoptosis of cardiac myocytes, proliferation and myocardial fibrosis. Our study did not show evidence of haemodynamic benefit or myocardial protective effect of oral enoximone treatment.

Healthy lung tissue response to mechanical ventilation in an experimental porcine model.

BACKGROUND: The aim of this comparative study was to assess the impact of two different settings of tidal volume (Vt) on the function and morphology of the mechanically ventilated lungs during a 12-h period. MATERIALS AND METHODS: A total of 32 animals were randomly divided into two groups. Group A included piglets ventilated with a Vt of 6 ml/kg and group B piglets ventilated with a Vt of 10 ml/kg. Lung functions and pulmonary mechanics were evaluated after 1 and 12 h of mechanical ventilation. Morphological changes of the lung tissue were evaluated at the end of the study. RESULTS: Twelve hours of lower Vt ventilation was associated with the development of respiratory acidosis but minimal histological changes. Higher Vt led to pronounced histological changes in terms of proliferation and apoptosis and a decrease of dynamic compliance, with a trend towards lower oxygenation during the study. CONCLUSION: Mechanical ventilation with a Vt of 6 ml/kg induces minimal histological lung parenchymal changes in terms of proliferation and apoptosis. Positive pressure mechanical ventilation with Vt of 10 ml/kg does not protect lung tissue and induces substantial proliferative and apoptotic changes within the lung parenchyma. Positive pressure mechanical ventilation with Vt of 10 ml/kg does not guarantee protection of healthy pulmonary tissue in the absence of a priming pulmonary insult.

Repeated bedside echocardiography in children with respiratory failure.

BACKGROUND: The aim of this study was to verify the benefits and limitations of repeated bedside echocardiographic examinations in children during mechanical ventilation. For the purposes of this study, we selected the data of over a time period from 2006 to 2010. METHODS: A total of 235 children, average age 3.21 (SD 1.32) years were included into the study and divided into etiopathogenic groups. High-risk groups comprised: Acute lung injury and acute respiratory distress syndrome (ALI/ARDS), return of spontaneous circulation after cardiopulmonary resuscitation (ROSC), bronchopulmonary dysplasia (BPD), cardiomyopathy (CMP) and cardiopulmonary disease (CPD). Transthoracic echocardiography was carried out during mechanical ventilation. The following data were collated for statistical evaluation: right and left ventricle myocardial performance indices (RV MPI; LV MPI), left ventricle shortening fraction (SF), cardiac output (CO), and the mitral valve ratio of peak velocity of early wave (E) to the peak velocity of active wave (A) as E/A ratio. The data was processed after a period of recovery, i.e. one hour after the introduction of invasive lines (time-1) and after 72 hours of comprehensive treatment (time-2). The overall development of parameters over time was compared within groups and between groups using the distribution-free Wilcoxons and two-way ANOVA tests. RESULTS: A total of 870 echocardiographic examinations were performed. At time-1 higher average values of RV MPI (0.34, SD 0.01 vs. 0.21, SD 0.01; p < 0.001) were found in all groups compared with reference values. Left ventricular load in the high-risk groups was expressed by a higher LV MPI (0.39, SD 0.13 vs. 0.29, SD 0.02; p < 0.01) and lower E/A ratio (0.95, SD 0.36 vs. 1.36, SD 0.64; p < 0.001), SF (0.37, SD 0.11 vs. 0.47, SD 0.02; p < 0.01) and CO (1.95, SD 0.37 vs. 2.94, SD 1.03; p < 0.01). At time-2 RV MPI were lower (0.25, SD 0.02 vs. 0.34, SD 0.01; p < 0.001), but remained higher compared with reference values (0.25, SD 0.02 vs. 0.21, SD 0.01; p < 0.05). Other parameters in high-risk groups were improved, but remained insignificantly different compared with reference values. CONCLUSION: Echocardiography complements standard monitoring of valuable information regarding cardiac load in real time. Chest excursion during mechanical ventilation does not reduce the quality of the acquired data.

Treatment of encapsulated pleural effusions in children: a prospective trial.

BACKGROUND: The aim of this study was to improve the efficacy of treatment of complicated pleural effusions. METHODS: In this prospective study, 76 consecutive children (average age 5.0 +/- 4.14 years) fulfilling the required classification criteria were duly treated with chest tube placement and divided into two groups depending on the presence of encapsulated or non-encapsulated effusions. Treatment of the former group was supplemented by intrapleural fibrinolysis. The effectiveness of treatment was assessed in terms of chest tube dwell-time and total length of hospitalization. Regression analysis was performed using independent factors that were associated with these dependent factors. Value differences for P < 0.05 were considered significant. RESULTS: The ultrasound pleural distance and lactic-dehydrogenase content in the pleural fluid was significantly associated with the length of treatment (P < 0.01). Improved response to treatment, reduced duration of hospitalization (9.2 +/- 1.9 vs 11.5 +/- 0.9; P < 0.01) and tube dwell-time (7.6 +/- 1.3 vs 9.5 +/- 0.9; P < 0.01) was achieved in the intrapleural-fibrinolysis-treated group (n= 38) compared with controls (n= 38), with virtually the same total tube output (606.1 +/- 257.5 vs 673.1 +/- 347.4; P= 0.175). All patients were completely cured. Following 104 applications of the fibrinolytic agent there was one change in coagulation parameters: hypofibrinogenemia (in 1%). CONCLUSIONS: The authors recommend intrapleural fibrinolysis as an effective and safe alternative treatment strategy in treating encapsulated pleural effusions in children.

[Lethal course of rotavirus gastroenteritis - a case history.].

The case of fatal course of rotaviral gastroenteritis at eight months old boy has been described. Two days history of frequent watery stools in home care, hyperosmolar dehydration grading to hypovolemic shock, cardiopulmonary resuscitation in regional hospital, transported comatose with vital functions support. In spite of temporary stabilization of the patient, there was retrogression to multiorgan failure (ischemic myocardial infliction, circulatory failure, ARDS, renal failure, DIC, enteritis, post ischemic hepatopathy). Four day later patient exits. Rotaviruses have been proved from stools specimen post mortem.