Persistent Eustachian valve and transient arterial hypoxemia in a newborn: a clinical observation

The Eustachian valve (EV) is located in the orifice of inferior vena cava and belongs to structures of the normal heart. It plays an important role in the fetal blood flow by directing the flow of blood from inferior vena cava through an open foramen ovale to the left atrium, thereby ensuring the systemic flow in a fetus and bypassing the pulmonary circulation. After birth and upon closure of the foramen ovale, the valve ceases to function and tends to regress. Usually, a prominent EV is a clinically non-significant ultrasound finding. In isolated cases, however, it can cause significant hemodynamic abnormalities and subsequent rhythm disorders, delayed fetal development and transient hypoxemia in newborns. It can extremely rare be a cause of blood right-toleft shunting through the foramen ovale leading to desaturation. Clinically it can manifest by central cyanosis in newborns and infants. The differential diagnosis is made in neonatal intensive care units. We present a case of transient arterial hypoxemia in a newborn with prominent EV and inter-atrial shunt. A one-month old infant was transferred from the Department of Pediatric Cardiology with a history of transient hypoxemic spells related to right-to-left shunting via atrial septal defect caused by obstruction of the tricuspid valve by the prominent EV. The instrumental findings including contrast-enhanced tomography supported this hypothesis. The patient was stable for subsequent 10 days of the follow-up, which allowed for further conservative managements until the conventional time point for children with an atrial septal defect. Potential regress of the prominent EV, as well as natural growth of an infant and his/hers intracardiac structures, provide mostly favorable outcome without a surgical intervention. This was clearly illustrated in the clinical case.

Determining a target SpO2 to maintain PaO2 within a physiological range

Objective In the context of an ongoing debate on the potential risks of hypoxemia and hyperoxemia, it seems prudent to maintain the partial arterial oxygen pressure (PaO2) in a physiological range during administration of supplemental oxygen. The PaO2 and peripheral oxygen saturation (SpO2) are closely related and both are used to monitor oxygenation status. However, SpO2 values cannot be used as an exact substitute for PaO2. The aim of this study in acutely ill and stable patients was to determine at which SpO2 level PaO2 is more or less certain to be in the physiological range. Methods This is an observational study prospectively collecting data pairs of PaO2 and SpO2 values in patients admitted to the emergency room or intensive care unit (Prospective Inpatient Acutely ill cohort; PIA cohort). A second cohort of retrospective data of patients who underwent pulmonary function testing was also included (Retrospective Outpatient Pulmonary cohort; ROP cohort). Arterial hypoxemia was defined as PaO2 < 60 mmHg and hyperoxemia as PaO2 > 125 mmHg. The SpO2 cut-off values with the lowest risk of hypoxemia and hyperoxemia were determined as the 95th percentile of the observed SpO2 values corresponding with the observed hypoxemic and hyperoxemic PaO2 values. Results 220 data pairs were collected in the PIA cohort. 95% of hypoxemic PaO2 measurements occurred in patients with an SpO2 below 94%, and 95% of hyperoxemic PaO2 measurements occurred in patients with an SpO2 above 96%. Additionally in the 1379 data pairs of the ROP cohort, 95% of hypoxemic PaO2 measurements occurred in patients with an SpO2 below 93%. Conclusion The SpO2 level marking an increased risk of arterial hypoxemia is not substantially different in acutely ill versus stable patients. In acutely ill patients receiving supplemental oxygen an SpO2 target of 95% maximizes the likelihood of maintaining PaO2 in the physiological range.

HOLTER ECG AND RESPIRATORY CURVE MONITORING IN NEWBORNS WITH CONGENITAL HEART DISEASE: PILOT CASE–CONTROL STUDY

Objective of the research: analysis of 24-hour ECG indicators with the search for heart rhythm disorders in children with congenital heart defects (CHD) during preparation for surgical correction of heart disease; determination of the number of apnea and periodic breathing (PB) episodes in children with CHD based on the daily pneumogram analysis. Materials and methods: 24-hour ECG monitoring with pneumogram (respiratory curve) recording was performed in 37 newborns in the late neonatal period, on the 13th [10; 16] (Me [95% CI]) day of life. Inclusion criteria: uncorrected congenital heart disease complicated by heart failure (HF) of functional class II – III according to R.D. Ross, and/or arterial hypoxemia. The group included patients whose heart disease hemodynamics did not require urgent or emergency cardiac surgery. The study was performed during the planned preparation for surgical treatment in somatic department. In CHD structure combined heart defects prevailed. Two children with tetralogy of Fallot had only arterial hypoxemia. The comparison group included 73 healthy full-term newborns examined in the early neonatal period – on the 2nd [2; 3] (Me [95% CI]) day of life before discharge. Researchers analyzed the heart rate (HR) during sleep and wakefulness, circadian index, heart rate variability (HRV), the frequency of heart rhythm disorders, the number and duration of apnea and PD episodes. Results and discussion: there was a significantly lower number of PD and sleep apnea episodes in newborns with hemodynamically significant CHD; parameters of HRV and heart rate in children with CHD are characterized by a high level of activity of nervous system sympathetic part due to a severe degree of HF and/or arterial hypoxemia; cardiac arrhythmias in newborns with CHD were represented by a rare single extrasystole.

Effect of training on the development of exercise-induced arterial hypoxemia in volleyball players

Background and Study Aim. The purpose of this study was to examine the effect of volleyball training on the development of exercise-induced arterial hypoxemia during incremental exercise in male competitive volleyball players. Material and Methods. Eight male amateur volleyball players (age 21±1.3 years) participated in a 6-week volleyball training program three times a week in the pre-season preparatory period. Before and after the training period, all players performed an incremental treadmill test to determine maximal oxygen uptake (VO2max), and oxyhemoglobin saturation (SaO2) was continuously measured using a pulse oximeter during the test. Maximal values of minute ventilation (VEmax), respiratory exchange ratio (RERmax), ventilatory equivalent for oxygen (VE/VO2) and carbon dioxide (VE/VCO2) were determined. Exercise-induced arterial hypoxemia (EIAH) was defined as a SaO2 decreased by at least 4% (ΔSaO2≤ −4%) from resting level. Results. All the players exhibited exercise-induced arterial hypoxemia before (ΔSaO2= –8.8±3.3%) and after (ΔSaO2= –8.31.5%) the training period. SaO2 was significantly decreased from 97.6±1% at rest to 88.7±2.7% at exhaustion before the training period, and from 97.2±1.1% at rest to 88.8±2.1% at exhaustion after training period (p < 0.001). There was no significant difference in resting and lowest SaO2 values by comparison between the before and after training (p > 0.05). There were no significant changes in VO2max, VEmax, RERmax, VE/VO2 and VE/VCO2 after training period (p > 0.05). Conclusions. The results of this study showed that volleyball players with a history of anaerobic training may exhibit EIAH, but that 6-week volleyball training has no effect on the degree of exercise-induced arterial hypoxemia.

Bronchial obstruction and resistance to hypoxia in elderly patients with COPD

Background. Age-related morphofunctional changes in the body lead to the development of arterial hypoxemia, tissue hypoxia and hypoxic changes. All this causes a decrease in the body’s resistance to hypoxia and contributes to the development of lung diseases, in particular, chronic obstructive pulmonary disease (COPD) in the elderly. With the development of COPD in the elderly due to bronchial obstruction and disorders of pulmonary gas exchange, age-related hypoxic shifts, arterial hypoxemia, tissue hypoxia and resistance to hypoxia are further reduced. However, the relationship between bronchial obstruction and resistance to hypoxia in elderly patients with COPD has not been studied. Objective. To identify the relationship between bronchial patency and resistance to hypoxia in elderly patients with COPD. Materials and methods. The study included 30 patients with COPD in the elderly (60-74 years), I-II stage, without exacerbation, with a disease duration of 7 to 26 years, risk groups A and B. The type and severity of pulmonary ventilation were assessed indicators of spirometry and the curve “flow/volume” of forced exhalation on the device Spirobank (Mir, Italy). To determine the body’s resistance to hypoxia, a hypoxic test with 12 % oxygen content was performed for 12 min with monitoring of blood saturation using the automated software and hardware complex Hypotron (Ukraine). Results. Researches have shown that under hypoxic exposure, blood saturation in elderly patients with COPD is reduced, on average, by 18.23±0.26 %. This decrease in blood saturation can be regarded as severe arterial hypoxemia. At the same time, in elderly patients with COPD with an increase in bronchial patency disorders, the saturation shifts in hypoxia, on average, also increase. There was a significant correlation (r=0.50; p=0.006) of blood saturation shifts in hypoxia with bronchial obstruction. Conclusions. In elderly patients with COPD, resistance to hypoxia is determined by bronchial obstruction.

A PROSPECTIVE CLINICAL ANALYSIS OF PULMONARY PROFILE IN PATIENTS WITH CIRRHOSIS OF LIVER WITH REFERENCE TO ARTERIAL OXYGEN SATURATION AND PULMONARY FUNCTION TESTS

BACKGROUND: Cirrhosis of liver and its complications including pulmonary dysfunction are a major cause of death among adults and have several clinical implications with regard to their early detection and management.OBJECTIVES OF THE STUDY:Evaluation of patients for pulmonary manifestations in cirrhotic patients with special reference to arterial hypoxemia and lung function.METHODOLOGY:A prospective analysis of cirrhotic patients fulfilling the inclusion and exclusion criteria.RESULTS:The prevalence of arterial hypoxemia in cirrhotic patients was present in 10 %,out of which 66.6% patients were detected to have Hepatopulmonary Syndrome (HPS).The severity of hypoxemia was positively correlated with severity of liver disease assessed by Child Pugh Score.CONCLUSION:Liver cirrhosis is associated with pulmonary complications.The early identification is crucial as it affects the prognosis and guides the further management.

Exercise-induced arterial hypoxemia; some answers, more questions

Exercise-induced arterial hypoxemia (EIAH) is characterized by the decrease in arterial oxygen tension and oxyhemoglobin saturation during dynamic aerobic exercise. Since the time of the initial observations, our knowledge and understanding of EIAH has grown, but many unknowns remain. The purpose of this review is to provide an update on recent findings, highlight areas of disagreement, and identify where information is lacking. Specifically, this review will place emphasis on (i) the occurrence of EIAH during submaximal exercise, (ii) whether there are sex differences in the development and severity of EIAH, and (iii) unresolved questions and future directions.

TOXIC PULMONARY EDEMA BY INHALATION OF PYROLYSIS PRODUCTS OF CHLORINATED PARAFFIN-70 IN RATS

In the study conducted on laboratory animals (rats) toxic pulmonary edema (TPE) was simulated by inhalation of pyrolysis products of chlorinated paraffin-70 (CP-70). The average-lethal dose of CP-70 burned at 280 ÷ 350 ° C for 3 minutes is 8.1 ± 0.9 g and provides a concentration of hydrogen chloride (HCl) in the chamber at the level of 7325 [5850; 8460] ppm. Under these conditions exposure for 30 minutes led to an increase in the pulmonary rate (LC) in laboratory animals 24 hours after poisoning. The diagnosis of TPE was confirmed histologically by the signs of interstitial and alveolar edema, as well as arterial hypoxemia (TI = 204.5 [180; 228]) indicating respiratory failure. The death of animals was recorded 3 days after application of the pyrolysis products of CP-70. The simulated experimental TPE model can be used to search for the means of pathogenetic therapy of pulmonary toxicants poisoning.