Search

In severe respiratory insufficiency, neonatal and pediatric patients should be ventilated artificially by a ventilator. Aim of this experimental study was to evaluate whether the newly developed ventilator Chirana Aura V may effectively ventilate the lungs of animals with two different models of acute lung injury: acute respiratory distress syndrome (ARDS) induced by repetitive saline lavage and meconium aspiration syndrome (MAS) induced by intratracheal instillation of neonatal meconium. The experiments were performed on 10 adult rabbits (New Zealand white). In ARDS group (n=5), the lungs were repetitively lavaged with saline (30 ml/kg) until partial pressure of oxygen (PaO2) in arterial blood was under 26.7 kPa at inspiratory fraction of oxygen FiO2=1.0. In MAS group (n=5), animals were instilled 4 ml/kg of suspension of human meconium (25 mg/ml). When the model of acute lung injury was developed, animals were ventilated for additional 2 hours with pressure control ventilation (PCV) regime by ventilator Chirana Aura V. Ventilatory parameters, blood gases, acid-base balance, end-tidal CO2, O2 saturation of hemoglobin, oxygenation indexes, ventilation efficiency index, dynamic lung compliance, and right-to-left pulmonary shunts were measured and calculated in regular time intervals. In both experimental groups, used ventilatory settings provided acceptable gas exchange within the period of observation. Thus, the results indicate that ventilator Chirana Aura V might be suitable for ventilation of animal models of acute lung injury. However, further pre-clinical investigation is needed before its use may be recommended in neonatal and/or pediatric patients with acute lung injury.

Abstract Objective Although the emotion regulatory difficulties in patients with major depressive disorder (MDD) are predicted to associate with impaired cardiovascular autonomic regulation, the changes of cardiac vagal regulation in MDD are incompletely understood. The aim of the study was to evaluate the respiratory sinus arrhythmia (as an index of cardiac vagal regulation) using the spectral analysis in high frequency band of the heart rate variability and the indices of deep breathing test in adolescent patients with major depressive disorder. Materials and methods Twenty-eight adolescent girls were examined - 14 patients with major depressive disorder without pharmacological treatment (average age: 16.4 ± 0.2 yr) and 14 healthy probands (control group) matched for age and gender. The respiratory sinus arrhythmia was evaluated using the spectral analysis in high frequency band of the heart rate variability (HF-HRV) and the parameters of deep breathing test (I-E, I/E). In addition, mean R-R interval was calculated. Results The adolescent patients with MDD had significantly reduced spectral activity in the HF-HRV and lower I/E, I-E parameters compared to matched healthy subjects (P < 0.05). Conclusions We conclude that the adolescent girls with MDD have reduced respiratory sinus arrhythmia indicating cardiac vagal dysregulation. Since impaired cardiac vagal regulation is associated with increased risk of cardiovascular morbidity, this finding underscores the importance of impaired autonomic neurocardiac integrity already in adolescents with major depressive disorder without pharmacological treatment.

The history of invasive blood pressure measurement, documented in the literature, begins with animal experiments in the 18th century. Stephen Hales was the first who published the methodology and results of invasive blood pressure measurements in „Statical Essays containing Haemastatics" in 1733, however, the measurements, including determination of the venous pressure, aortic blood flow rate, cardiac output, and others parameters in different situations were made in the first and second decades of the 18th century. Poisseuille improved the measurement of the blood pressure with the invention of the hemodynamometer, U-tube filled with mercury. Continuous registration of blood pressure has been made possible since 1847 by the kymograph - Ludwig's invention and the use of a float in the hemodynamometer. For the first time in humans was this method used by Faivre (1856) in three men during limb amputation. To measure blood pressure in various parts of the circulation, including the heart was necessary to introduce catheterizations. Catheterizations in experimental animals were used by Claude Bernard, Chauveau and Marey. The greatest contribution to the development of methods for cardiac catheterization in humans have Dieffenbach, Bleichröder, Unger, Montanari and Nobel Prize winner Forssmann. Very important role in the further development of cardiovascular catheterization played later Klein, Cournand, Richardson, Swan and Ganz. The exact year of beginning of the invasive blood pressure measurement in neonates is unknown. In 1938, Woodbury published a paper about measuring blood pressure in a. umbilicalis using Hamilton's hypodermic manometer. Diamond (1947) and James (1959) contributed to the development of catheterization of umbilical vessels. At the beginning of the sixties of the 20th century, thanks to the construction of accurate electromanometers and suitable catheters, there was a breakthrough in the invasive measurement of blood pressure in newborns. Wallgren, Rudolph, Moss, Gupta and Scopes were the pioneers of invasive blood pressure measurement in newborns. Recently, the direct invasive monitoring of blood pressure in neonatology is the gold standard. This method is necessary when obtaining beat-to-beat BP values and when non-invasive methods cannot be used. [ABSTRACT FROM AUTHOR]

Relationships between the values of heart rate variability and blood pressure and parameters of growth and development in premature infants Introduction: The dynamics of the development of the cardiovascular system in the early postnatal period also depends on the maturity of the newborn. The aim of the study was to determine the relationships between cardiovascular parameters – heart rate variability, its components (LF, HF), pulse intervals (interbeat intervals – IBI), heart rate, systemic blood pressure and parameters reflecting development and growth – gestational age, postconceptional age, birth and actual weight in the group of premature babies in the first weeks of life. Methods: In 43 premature infants of various gestational ages, birth and actual weights, at a mean postconception age of 34.6 weeks, blood pressure and heart rate were continuously and non-invasively recorded. Blood pressure was recorded continuously for 2–5 minutes under standard conditions using a Portapres device (FMS). For each child, a stationary segment of the record containing 250 beat-to-beat blood pressure values was analyzed. The variability of interbeat intervals was determined by spectral analysis (total power, powers in high-frequency and low-frequency bands) in 35 children. Results: Correlation tests (Pearson´s and Spearman´s) revealed positive correlations between gestational, postconceptional age, birth and actual weight and mean value of pulse intervals (IBI), spectral total power of the IBI variability, as well as spectral powers in HF and LF bands, and diastolic and mean blood pressure. There was a significant negative correlation between the ages and weights and mean heart and respiratory rate. Conclusion: Preterm infants with higher gestational and postconceptional age, birth and actual weight have higher total power of heart rate variability.This is not only a consequence of the increase in spectral power in the HF band, but also in the LF band, which through the activities of the sympathetic and parasympathetic systems reflects mainly baroreflex activity. Together, the mean heart rate is lower and blood pressure, diastolic and mean are higher. The identified relationships point to the increasing baroreflex sensitivity and to the maturation of regulatory circuits of the cardiovascular system in premature infants. [ABSTRACT FROM AUTHOR]

hototherapy is the most frequent therapeutic intervention in neonatal wards during the first days of life. The beneficial effect of light on decreasing serum bilirubin level was first described by Cremer and colleagues in the 1950s. Since then, phototherapy has been used effectively in the treatment of severe hyperbilirubinaemia and has almost completely eliminated exchange transfusion. Phototherapy is a non-invasive method, but, in addition to decreasing bilirubin levels, it may affect some other function, e.g. organ perfusion, especially in skin, peripheral vascular resistance, blood flow distribution, heart frequency, systemic blood pressure and breathing. The next component of applied light is a certain influx of heat that warms the body surface up. There is a risk of exogenous overheating and increased water loss by skin. We analyzed the effect of phototherapy on blood pressure and other parameters such as heart rate, respiratory rate, oxygen saturation, skin and rectal temperature. Comparison of control group (n=20) with patients with hyperbilirubinaemia and phototherapy (n=20) showed significant changes in some monitored parameters. Systolic, mean and diastolic blood pressure decreased significantly after the first hour of phototherapy (p=0.001; p=0.000; p=0.001), while at the end of the 2nd hour of phototherapy the drop was even more pronounced (p=0.002; p=0.000; p=0.003). During phototherapy, heart rate increased after 1 hour, even more significantly at the end of the 2nd hour of phototherapy (p=0.008; p=0.002), the respiratory rate also increased (p=0.033; p=0.015). These changes were accompanied by increasing skin and central (rectal) temperature. Based on the results, there are changes in some physiological parameters during phototherapy in newborns. Consistent monitoring of vital signs should therefore be an obvious part of care of the newborn during the treatment with blue light. [ABSTRACT FROM AUTHOR]

Postnatal transition is a complex process predominantly affecting cardiovascular and respiratory system immediately after birth. This includes spontaneous and regular breathing and physiological, as well as anatomical cardiovascular changes. Technological progress offers new possibilities for monitoring of vital signs more effectively and non-invasively. Heart rate is the most useful parameter reflecting the course of immediate postnatal adaptation and together with blood oxygen saturations belong to standard monitoring of adaptation process. New technologies, such as heart rate variability and near-infrared spectroscopy have been recently implemented into neonatal clinical research and practice. Better understanding of physiology and pathophysiology of postnatal adaptation mechanisms can help the practitioners to adjust preventative and therapeutic interventions and minimize their adverse effects, especially in preterm babies. Recent data about cardiovascular and haemodynamic monitoring during the early postnatal and neonatal period is presented in this article. [ABSTRACT FROM AUTHOR]

Apnea, especially in preterm newborns (AoP) is one of the common problems encountered at neonatal units. Numerous factors are likely to play a role in the etiology of apnea. Recent data sugest a role for genetic predisposition of AoP. It seems, that physiological rather than pathological immaturity of the respiratory, or cardiorespiratory control, play a major part in the pathophysiology of AoP. Immaturity of the brainstem, cerebral cortex, receptors of the lungs and the airways as well as of the chemoreceptors contribute to the development of apnea in preterm newborns. Several neurotransmitters (GABA, adenosin, endorphins) and their maturational changes are including in pathogenesis of apnea, too. The instability of the upper airway in preterm infants, asynchrony of musculature of the upper airway and diaphragm, pathological changes in the upper airway and malformations of the central nervous system might also contribute to the occurrence and severity of AoP. In newborns, apnea occurs more frequently in active sleep than in quiet sleep and the frequency of apnea in active sleep is higher in the warm conditions. Durations of apnea correlate with the body heat loss. Cardiovascular changes during apnea - bradycardia, peripheral vasoconstriction and various changes in peripheral blood flow and pressure occur together with changes in ECG. The standard clinical management of apnea includes non-pharmacological treatment (eliciting arousal reactions and reflex breathing by mechanical skin, or mucosa stimulations), pharmacological treatment (methylxanthines are preferred) and application of continuous positive airway pressure (CPAP) or in severe apnea - mechanical ventilation. [ABSTRACT FROM AUTHOR]