A Newly Developed Sublingual Tonometric Method for the Evaluation of Tissue Perfusion and Its Validation In Vitro and in Healthy Persons In Vivo and the Results of the Measurements in COPD Patients.

Introduction. Since its first publication in the medical literature, an extremely large number of references have demonstrated that the tonometric measurement of tissue perfusion is a reliable indicator of the actual condition of critically ill patients. Later a new method was developed by the introduction of sublingual tonometry for the determination of tissue perfusion. In comparison with gastric tonometry, the new method was simpler and could even be used in awake patients. Unfortunately, at present, because of severe failures of manufacturing, the device is withdrawn from commerce. Materials and Methods. In this study, we present a new method using a newly developed tool for the PslCO2 measurement in sublingual tonometry as well as the data for its validation in vitro and in vivo and the results of 25 volunteers and 54 COPD patients belonging to different GOLD groups at their hospitalization due to the acute exacerbation of the disease but already in a stable condition at the time of the examination. Results and Conclusion. The results of the performed examinations showed that the method is suitable for monitoring the actual condition of the patients by mucosal perfusion tonometry in the sublingual region.

Measurement of gastric-to-end-tidal carbon dioxide difference in neonates requiring intensive care.

OBJECTIVE: Gastric-arterial partial CO(2) pressure gap (P(g-)(a)CO(2) gap) measured by gastric tonometry may detect the disturbance of splanchnic perfusion. As in the neonatal age it is very difficult to follow up the circulatory condition with frequent acid-base examinations, we wanted to compare the P(g-)(a)CO(2) gap with an alternative gap of P(g)CO(2) - end-tidal carbon dioxide (P(g)(-)(ET)CO(2) gap). METHODS: A prospective study was performed on ventilated neonates requiring intensive therapy (n = 44, weight: 1813 ± 977 g). P(ET)CO(2) and P(g)CO(2) were measured with a side stream capnograph. We applied a newly developed gastric tonometric probe. Patients were divided into two groups: Group 1 of patients in stable condition (n = 35) and Group 2 of patients with severe condition (i.e. Clinical Risk Index for Babies [CRIB] score higher than 10; n = 9). For main statistical analysis a mixed model repeated measurements ANOVA, Bland-Altman analysis were applied. RESULTS: P(g)(-)(ET)CO(2) gap was higher than P(g-)(a)CO(2) gap (11.40 ± 7.79 versus 3.63 ± 7.98 mmHg, p < 0.01). Both gaps were higher in Group 2 (8.71 ± 10.89 and 18.27 ± 10.49 versus 2.53 ± 6.78 and 9.92 ± 6.22 mmHg, p < 0.01 and p < 0.05). Bland-Altman analysis of the two gaps showed an acceptable correspondence. CONCLUSIONS: P(g)(-)(ET)CO(2) gap may be used as a method for continuous estimation of splanchnic perfusion and a prognostic index also in critically ill neonates. However, the P(g-)(a)CO(2) gap should not be abandoned.

Results of and further prevention of hypoxic fetal brain damage by inhibition of xanthine oxidase enzyme with allopurinol.

Several experimental models on adult and newborn animals showed that in cerebral hypoxic-ischemic conditions similar to clinical states the main source of the excessive production of free oxygen radicals is the highly activated xanthine oxidase (XO) enzyme reaction. Long before this data were available, it became known that the main role of allopurinol (AP) is the inhibition of XO. On the basis of these results, many therapeutic trials with AP were performed both in experimental and clinical studies of ischemia and reperfusion. However, it has been shown that only preventive administration of AP has favorable effects. The explanation for the poor results of AP treatment in human fetal brain damage (FBD) cases is that the drug was applied postnatally. The clinical studies performed in healthy laboring mothers whose deliveries were complicated with FBD showed that placental transfer after prenatal administration of AP may be effective in protecting newborns at increased risk of hypoxic-ischemic cerebral damage. Further controlled trials are required to determine if the prophylactic use of the drug might prevent hypoxic-ischemic injuries when the drug is administered immediately prior to impending fetal hypoxia, or even in deliveries at risk of developing hypoxia.

Practical experiences and in vitro and in vivo validation studies with a new gastric tonometric probe in human adult patients.

PURPOSE: This study provides practical experiences with a new, simple, balloon-free gastric tonometric probe (probe) and reports the results of simultaneous in vitro and in vivo measurements with a conventional, ballooned gastric air tonometer (catheter) and the new device. MATERIALS AND METHODS: Ten healthy volunteers and 50 anesthetized surgical patients with different American Society of Anesthesiologists (ASA) scores, scheduled for neurologic, orthopedic, trauma, and cardiac operations, were enrolled in the study. The values of 60 in vitro and, in 12 surgical patients, 101 in vivo paired Pco(2) measurements--performed simultaneously with the new tonometric probe and the catheter that was connected to a Tonocap monitor--were compared. The tolerability of the measurement with the new probe was examined, and the results of gastric tonometry and, in surgical cases, the gastric tonometric, end-expiratory, and arterial Pco(2) values were registered. The results were evaluated by analysis of variance test. The data of the in vivo paired measurements were evaluated by Bland-Altman analysis. RESULTS: The use of the probe proved to be well tolerated and easily applicable in the studied cases. The results of 20 measurements obtained in healthy volunteers and those of 520 measurements in the surgical cases correspond to the data obtained with the classical methods published in the medical literature. During in vitro paired measurements, there was a good agreement between the data obtained with the 2 methods; however, in the in vivo studies, the results of measurements performed with the probe were mostly higher. CONCLUSIONS: The differences between the results obtained with the 2 methods might have been caused by the quicker equilibration property of the probe and by the fundamental differences between the 2 methods. The new probe seems to be applicable for routine human measurements.

Applicability of a new gastric tonometric probe in infants requiring intensive care.

BACKGROUND: Gastric tonometry was developed for measuring the partial pressure of carbon dioxide in the gastrointestinal tract and particularly for monitoring the clinical condition of patients in critical states. The ballooned catheter used in this technique has proved to be a reliable tool in adult patients, but its use in pediatrics is limited because of technical difficulties. The aims of this paper are to describe the technique of application of a recently developed gastric tonometric probe especially suitable for performing measurements on neonates and infants and to present the first human results. MATERIAL/METHODS: Thirty-two neonates and infants requiring intensive care were monitored (age: 2-456 days, weight: 1200-6700 g), of whom 10 died. The pediatric index of mortality, acid-base parameters, PCO2 gap values, and intramucosal pH and pH gap values were measured or calculated. The new gastric tonometric probe, made of silicone rubber tubes, is balloon free. It is introduced into the stomach orally or nasopharyngeally through the use of a guide wire. After equilibration, the PCO2 level of the air inside the probe is measured with a capnograph. RESULTS: Application of the new probe proved simple. The pediatric index of mortality scores (35.1%+/-19.6% vs. 14.6%+/-14.8%), PCO2 gap values (13.48+/-9.30 mmHg vs. 8.43+/-6.54 mmHg), and the systemic-intramucosal pH differences (0.124+/-0.074 vs. 0.079+/-0.054) were significantly higher in the non-surviving patients. CONCLUSIONS: The new probe is well applicable for measurements of gastric PCO2 levels in infants.

Intraoperative gastric tonometric examinations in children and infants with a new probe, combined with measurement of the endtidal PCO2.

BACKGROUND: Important progress relating to the early prediction of postoperative complications was recently achieved through the combined use of endtidal PCO(2) (P(ET)CO(2)) and gastric tonometry. The aim of this article was to present results obtained with a new tonometric instrument, proving its feasibility and extending its use to the control of anesthetized infants and children. METHODS: The new tonometric probe, which is balloon free, consists basically of silicone rubber tubing. The room air initially inside the tubes of the probe equilibrates with the PCO(2) of the body cavity throughout its full length. The PCO(2) content of the gastric cavity (P(g)CO(2)) and simultaneously P(ET)CO(2) were measured with a microcapnograph. A total of 108 measurements were performed intraoperatively on 25 infants and young children operated on at the Surgical Unit of the Department of Pediatrics. The patients were divided into elective surgery cases <2 years of age, group I; elective surgery cases >2 years of age, group II; and acute surgery cases, independently of age, group III. To examine the degree of agreement between the measurements, Pearson's correlation coefficients were determined and Bland-Altman analysis was performed. A mixed model repeated measurements anova was used to compare the differences between the groups. RESULTS: P(ET)CO(2) and P(g)CO(2) for groups I and II were nearly identical, and statistically not significantly different (mean difference 0.10 mmHg and 0.85 mmHg, P = 0.96 and 0.45, respectively), whereas the corresponding data for group III differed significantly from those for groups I and II (P = 0.03 and 0.001, respectively). On Bland-Altman analysis, the bias value for groups proved to be statistically significantly different (P = 0.001). CONCLUSIONS: The tested new probe worked very well in small children. The clinical implications of the large gaps found between P(ET)CO(2) and P(g)CO(2) values in acutely ill children and children undergoing elective operations must be investigated further.

The founding and early history of the European Society for Paediatric Nephrology (ESPN).

The founding of the European Society for Paediatric Nephrology (ESPN) in 1967 was the milestone for pediatric nephrology in Europe. Now, at the beginning of the 21st century, more than 2,000 European pediatricians in 46 European countries work in the field of pediatric nephrology, and approximately 500 of these meet regularly at the annual ESPN meetings. Half of these 2,000 pediatricians work in about 200 specialized pediatric nephrology centers in tertiary care units, whereas the other half work in secondary pediatric care, with a special interest in common renal diseases. In this article the founding and early years of the ESPN are outlined and include the structure of the first ten annual ESPN meetings from 1967-1976. Historical reports are given by five pioneers who were first-hand witnesses of the development of pediatric renal care in Europe.

[Development of gastrotonometry and the future of its use in the monitoring of critically ill patients]. / A gasztrotonometria fejlodése és a vizsgálat alkalmazásának távlatai a súlyos állapotú betegek ellenorzésében.

Gastrotonometry conventionally enables the measurement of the partial pressure of carbon-dioxide (pCO2) in the gastric mucosa via the analysis of the filling material of a ballooned probe placed into the stomach. According to the data of the more than a half century long history of the method we may state, that the examination triggered an unusually large interest as well as was applied both in clinical work and in research. Since in the case of good circulatory circumstances the result of the examination is nearly equal to the value of the arterial blood pCO2, in the beginning the method was used for the better setting of ventilators of poliomyelitic patients with respiratory paralysis. Later it was also explored, that in critically ill patients the pCO2 value is significantly higher, than that of the arterial blood value, which difference is the consequence of the disturbance in the regional perfusion of the gastrointestinal system. The attention toward the subject was mainly drawn by the circumstance that the examination of the patient's condition can be judged objectively. Even more important is that gastrotonometry may help in the prediction of a life-threatening event. One of the main purposes of the article was the summarising of the literature on the subject, as well as reviewing the aspects, which should urge clinicians to apply gastrotonometry in a broader range of everyday clinical practice. On the other hand, the authors also give a short description of a new, self-developed balloon-free probe.

Xanthine oxidase activation in mild gestational hypertension.

OBJECTIVE: We hypothesized that activation of the xanthine oxidase (XO) enzyme system is a potential source of free radicals in pregnancy-induced hypertension (PIH). METHODS: A prospective observational study was carried out on 16 pregnant women who met the criteria of gestational hypertension [rise in blood pressure (BP) of 30 mm Hg systolic or 15 mm Hg diastolic after 20 weeks gestation or BP>140/90 mm Hg if earlier pressure is unknown] without proteinuria or any signs of renal impairment. Fourteen women with a clinically normal pregnancy matched for maternal age, parity, and gestational age acted as pregnant controls. Nonpregnant control women were members of the laboratory staff ( n=15). MAIN OUTCOME MEASURES: Concentrations of free sulfhydryl (SH) groups, purine catabolites, lipid peroxidation products in plasma, and blood carboxyhemoglobin levels were used to follow oxidative stress and potential hemolysis. A noninvasive measurement of functional XO activity was carried out (i.e., the urinary ratio of the two metabolites of caffeine was estimated). RESULTS: A pronounced oxidative stress was demonstrated in plasma samples of patients with hypertension by the elevated concentrations of uric acid and lipid peroxidation products. A reduced level of free sulfhydryl groups and an increased concentration of hypoxanthine (HX) were shown in normotensive pregnant individuals. The XO activity index was substantially higher in overweight pregnant subjects with mild hypertension [0.849+/-0.096 ( p<0.01)] than in normotensive pregnant women or in age-matched nonpregnant subjects [0.596+/-0.105, 0.542+/-0.049 (means+/-SD), respectively]. CONCLUSIONS: Our study of mildly hypertensive pregnant subjects provides additional evidence of the putative role of XO activation as a source of free radicals in the early stage of endothelial dysfunction.