Acid-base Balance Parameters Research Articles

Hidden acidosis: an explanation of acid–base and lactate changes occurring in umbilical cord blood after delayed sampling

To explore the 'hidden acidosis' phenomenon, in which there is a washout of acid metabolites from peripheral tissues in both vaginal and abdominal deliveries, by investigating temporal umbilical cord blood acid-base and lactate changes after delayed blood sampling. Prospective comparative study. University hospital. Umbilical cord blood from 124 newborns. Arterial and venous cord blood was sampled immediately after birth (T₀), and at 45 seconds (T₄₅), from unclamped cords with intact pulsations taken from 66 neonates born vaginally and 58 neonates born via planned caesarean section at 36-42 weeks of gestation. Non-parametric tests were used for statistical comparisons, with P < 0.05 considered significant. Temporal changes (T₀-T₄₅) in umbilical cord blood pH, the partial pressure of CO₂ (PCO₂) and O₂ (PO₂), and in the concentrations of lactate, haematocrit (Hct), and haemoglobin (Hb). In both groups all arterial parameters, except for PCO₂ in the group delivered by caesarean section, changed significantly (pH decreased and the other variables increased). There were corresponding changes in venous acid-base parameters. When temporal arterial changes were compared between the two groups, the decrease in pH and increase in PCO₂ were more pronounced in the group delivered vaginally. Neonates born vaginally had significantly lower pH and higher lactate, Hct, and Hb concentrations at T₀ and T₄₅ in both the artery and the vein. At T₄₅, arterial PCO₂ and PO₂ levels in the group delivered vaginally were also significantly higher. Delayed umbilical cord sampling affected the acid-base balance and haematological parameters after both vaginal and caesarean deliveries, although the effect was more marked in the group delivered vaginally. The hidden acidosis phenomenon explains this change towards acidaemia and lactaemia. Arterial haemoconcentration was not the explanation of the acid-base drift.

The impact of colloid infusion prior to spinal anaesthesia for caesarean section on the condition of a newborn — a comparison of balanced and unbalanced hydroxyethyl starch 130/0.4

Fluid therapy is the most commonly used treatment to prevent hypotension associated with spinal anaesthesia. The aim of this study was to test the hypothesis that a balanced solution of 6% hydroxyethyl starch will have a more beneficial impact on the condition of newborns at birth than an unbalanced 6% solution of HES. The study participants included 51 healthy parturients undergoing elective caesarean section with spinal anaesthesia. Patients received a transfusion of 500 mL of unbalanced 6% HES (Voluven) or balanced 6% HES (Tetraspan) prior to anaesthesia. The condition of the newborn was assessed using the Apgar score, and the acid-base balances of venous and arterial umbilical cord blood were also measured. The incidence of hypotension after spinal anaesthesia was 80% in Group A and 76.9% in Group B (P = 1.0). There were no differences between the two groups in the total doses of ephedrine and no differences between treatment groups in Apgar scores. Also, no differences in acid-base balance parameters (pH, H(+), pCO(2), pO(2), HCO(3)(-), BE) were found. A balanced 6% solution of hydroxyethyl starch (HES 130/0.42) did not significantly influence the condition of the newborns at birth or the acid-base and electrolyte concentration of newborns compared to an unbalanced solution of 6% hydroxyethyl starch (HES 130/0.4).

Experimentally induced hyperchloremic and dl-lactic acidosis in calves: An attempt to study the effects of oral rehydration on acid-base status

Many diarrheic calves suffer from metabolic acidosis, which is commonly treated by oral rehydration therapy. Oral rehydration solutions can be prepared in water, milk, or milk replacer. Therefore, the aim of the study was to verify dietary effects of water- or milk replacer-based oral rehydration solutions on parameters of acid-base balance in calves with experimentally induced hyperchloremic and dl-lactate acidosis. In 12 calves, hyperchloremic or dl-lactate acidosis was induced by HCl or dl-lactic acid infusions according to protocols outlined in previous literature. Immediately after induction, the calves were fed with milk replacer or water- or milk replacer-based oral rehydration solutions, or remained fasting, respectively. Blood samples were taken to monitor acid-base status over an experimental period of 4h. Using the protocols, all calves revealed a manifest hyperchloremic or dl-lactate acidosis. Because of high infusion volumes, plasma volume was expanded and effects of feeding regimens on blood parameters were rare. Unexpected clinical aberrations occurred after repeated induction of dl-lactate acidosis: all calves developed a thrombophlebitis of the jugular vein, whereas HCl infusion had no effect on endothelium. Induction of acidosis via infusion is not suitable to study dietary effects. A protocol to induce acidosis and dehydration simultaneously is required to duplicate the metabolic conditions of diarrheic calves. In further investigations, attention should be focused on effects of d-lactate or its metabolites on endothelial tissue.

FEATURES OF GAS EXCHANGE DURING MULTISTAGE SURGICAL INTERVENTION FOR TRAUMATIC SPINE INJURY

Objective. To study gas composition and acid-base balance of blood in the course of multistage surgical intervention for traumatic spine injury. Material and Methods. Gas composition and acid-base balance of blood were analyzed in 51 patients with traumatic spine injuries during multistage surgical treatment in a single operation. Patients were divided into two groups: Group 1 included 26 patients operated on under TIVA with propofol, fentanyl, and еsmeron; and Group 2 included 25 patients operated on under general anesthesia with sevoflurane in low-flow ventilation mode, fentanyl, and еsmeron. Results. In both groups acid-base balance parameters in blood were characterized by unidirectional changes depending on the state of compensated metabolic acidosis. More essential fluctuations in pH, and in the excess or deficit of buffer bases depended on the type of surgical intervention. They were more statistically significant during anterior procedures in condition of open pneumothorax requiring changes in lung ventilation parameters. Values of paO2 and paCO2 remained relatively stable in both groups at the study stages. Conclusion. Main factors determining changes in blood gas parameters during spine surgery are specific features of the anterior fusion procedure and its succession in the course of multistage surgical intervention. Hir. Pozvonoc. 2012;(2):79-86.

Determination of Acid-Base Balance During the Acute Stage of Experimental Pulmonary Barotrauma and After its Hyperbaric Treatment

Abstract The aim of the presented study was to determine whether pulmonary barotrauma without pneumothorax affects the parameters of acid-base balance. The experiment was conducted on rabbits divided into experimental and control groups. The animals from the experimental group were subjected to compression in the hyperbaric chamber and pulmonary barotrauma was induced using a method developed by authors. The arterial blood was sampled before the experiment, after anaesthesia and intubation, after injury, and after treatment (in the group undergoing hyperbaric therapy). All parameters of acid-base balance were found to be within the reference ranges. Since the biggest changes were observed after anaesthesia and intubation and not after the injury, it was concluded that pulmonary barotrauma had no significant effect on the parameters of acid-base balance.

Acid-Base Changes in Young Men after Oral Intake of Ethanol

Acid-Base Changes in Young Men after Oral Intake of EthanolThe authors studied a group of healthy men of an average age 24.4±2.1 yrs (x ± SEM) before the oral intake of ethanol and 1 and 2 hours after its ingestion. The volunteers, n= 10, of an average weight 79.1 kg ± 2.7 kg (± SEM) consumed within one minute 0.42 g ethanol/kg of individual body weight diluted in water (ratio 1:3). Concentrations of alcohol in venous blood were determined using Widmark method. One hour after the peroral intake the ethanol concentration reached 0.39±0.02 g/kg, 2 hours after peroral intake it was 0.33±0.03 g/kg.Parameters of acid-base balance (ABB) from venous blood samples were monitored in probands. Compared with baseline values, the pH of blood did not change significantly. The values of pCO2 in blood were significantly decreased, even the values of actual HCO3 and standard HCO3. The decrease of base excess continued 2 hours after intake of ethanol. There were significant variations in ABB (paired t - test), however in tolerable range. The values of glycaemia, AST, ALT, GGT, and AMS before ethanol intake and 1 and 2 hours after intake of ethanol were in the reference range and they did

Comparison of the utility of the classic model (the Henderson-Hasselbach equation) and the Stewart model (Strong Ion Approach) for the diagnostics of acid-base balance disorders in dogs with right sided heart failure

Classically, the acid-base balance (ABB) is described by the Henderson-Hasselbach equation, where the blood pH is a result of a metabolic components--the HCO3(-) concentration and a respiratory component--pCO2. The Stewart model assumes that the proper understanding of the organisms ABB is based on an analysis of: pCO2, Strong Ion difference (SID)--the difference strong cation and anion concentrations in the blood serum, and the Acid total (Atot)--the total concentration of nonvolatile weak acids. Right sided heart failure in dogs causes serious haemodynamic disorders in the form of peripheral stasis leading to formation of transudates in body cavities, which in turn causes ABB respiratory and metabolic disorders. The study was aimed at analysing the ABB parameters with the use of the classic method and the Stewart model in dogs with the right sided heart failure and a comparison of both methods for the purpose of their diagnostic and therapeutic utility. The study was conducted on 10 dogs with diagnosed right sided heart failure. Arterial and venous blood was drawn from the animals. Analysis of pH, pCO2 and HCO3(-) was performed from samples of arterial blood. Concentrations of Na+, K+, Cl(-), P(inorganic), albumins and lactate were determined from venous blood samples and values of Strong Ion difference of Na+, K+ and Cl(-) (SID3), Strong Ion difference of Na+, K+, Cl(-) and lactate (SID4), Atot, Strong Ion difference effective (SIDe) and Strong Ion Gap (SIG4) were calculated. The conclusions are as follows: 1) diagnosis of ABB disorders on the basis of the Stewart model showed metabolic alkalosis in all dogs examined, 2) in cases of circulatory system diseases, methodology based on the Stewart model should be applied for ABB disorder diagnosis, 3) if a diagnosis of ABB disorders is necessary, determination of pH, pCO2 and HCO3(-) as well as concentrations of albumins and P(inorganic) should be determined on a routine basis, 4) for ABB disorder diagnosis, the classic model should be used only when the concentrations of albumins and P(inorganic) are normal.

Influence of Physical Activity on Metabolic State Within a 3-h Interruption of Continuous Subcutaneous Insulin Infusion in Patients with Type 1 Diabetes

The aim of this study was to evaluate the influence of physical activity on blood glucose, insulinemia, and ketone bodies level during interruption of insulin delivery. We enrolled 12 patients with type 1 diabetes (men with an average age of 33.4±8.66 years, body mass index of 25.7±3.75 mg/m(2), and glycated hemoglobin of 8.4±0.95%). The test was performed after overnight fasting at the usual insulin dosage. The delivery of insulin by the pump was stopped for 3 h, and blood samples were obtained in 30-min intervals for determination of blood glucose, insulinemia, β-hydroxybutyrate, non-esterified fatty acids, and acid-base balance parameters. A test with (EXE) or without (CON) physical exercise (moderate aerobic exercise) was performed in each patient at random in the course of 2 weeks. Results are presented as median (first quartile; third quartile). Groups CON and EXE did not differ in blood levels of insulin during the test. Regarding time course of glycemia, we found differences only in min 270 for CON versus EXE of 15.2 (13.6; 16.7) and 13.9 (9.1;16.5) mmol/L, respectively (P=0.038). Concerning blood levels of β-hydroxybutyrate, we found significant differences in min 180-300 of the test: CON of 419 (354; 541), 485 (344; 580), and 107 (63; 156) μmol/L versus EXE of 690 (631; 723), 703 (562; 871), and 241 (113; 507) μmol/L (P<0.01). Comparable results were found in values of total ketone bodies and free fatty acids. The influence of physical activity during a 3-h interruption of insulin pump treatment is evident, especially in the increase in plasma levels of non-esterified fatty acids and ketone bodies. Correction bolus leads to a rapid increase in insulinemia; however, normalization of blood glucose and ketone bodies is achieved within another 90 min.

Use of Heliox in the Management of Neonates with Meconium Aspiration Syndrome

Background: Helium-oxygen mixture (heliox) ventilation has been known as an alternative treatment in patients with airway obstruction. Because of the physical properties of heliox, mechanical ventilation with this gas mixture may offer advantages in the management of respiratory failure associated with meconium aspiration syndrome (MAS). Objectives: The purpose of this pilot study was to assess the effect of short-term mechanical ventilation with heliox in newborns with MAS on vital signs, oxygenation, acid-base balance and respiratory function parameters. Methods: The study was carried out in newborns with respiratory failure requiring mechanical ventilation due to MAS. Eight patients were ventilated using pressure-controlled synchronized intermittent mandatory ventilation. Parameters of respiratory function, oxygenation, acid-base balance and vital signs were recorded at baseline, then twice during 1 h of heliox ventilation and finally twice during 1 h after switching back to air-oxygen ventilation. Results: Mechanical ventilation with heliox did not affect vital signs and the infants’ clinical condition remained stable during the study. Heliox ventilation was associated with a nonsignificant increase in tidal volume, minute ventilation and peak expiratory flow rate values. Mechanical ventilation with heliox allowed the use of significantly lower FiO₂, with a significant decrease in alveolar-arterial oxygen tension difference and a decrease in the oxygenation index which was not statistically significant. There was also a significant increase in the PaO₂/FiO₂ ratio during heliox ventilation. Conclusions: Ventilation with a helium and oxygen mixture had a positive effect on the selected parameters of oxygenation, while its effects on other respiratory parameters were relatively small.

Influence of the wing-of-the-nostrils correction procedure on the change of the acid-base balance parameters and oxygen concentration in the arterial blood in French bulldogs

Brachycephalic syndrome develops as a result of a specific build of splanchnocranium. In dogs of brachycephalic breeds, an impairment of correct gas exchange occurs. 5 French bulldogs at the age of 11-14 months, which suffered from continuous mixed-type dispnoea and lowered effort tolerance, were examined. Apart from the above-mentioned symptoms, the occurrence of strong external nostril stenosis was noted in the clinical examination. The symptoms observed together with the nostril stenosis indicated a possibility of an occurrence of the brachycephalic syndrome. 1 ml of full blood was drawn from the femoral artery. Acid-base balance parameters were determined in the arterial blood: pH, pCO2, HCO3-, and pO2. The wing-of-the-nostrils correction procedure were carried out in general anaesthesia. In premedication, the patients received medetomidine and after 15 minutes, fentanyl together with atropine. The induction of propofol was carried out. After four weeks from the procedure, blood was collected and the acid-base balance and pO2 parameters were again determined. The obtained values of the acid-base balance and pO2 parameters showed a noticeable influence of the wing-of-the-nostrils correction procedure on the values of the parameters determined. The results of the blood gasometry obtained prior to the procedure clearly indicate the occurrence of respiratory acidosis. The correction of wings of the nostrils significantly influenced saturation of the arterial blood with oxygen and the symptoms of dispnoea observed by the owners and episodes of apnoea and the loss of consciousness entirely subsided.

506 Heliox in the Management of Neonates with Meconium Aspiration Syndrome (MAS)

The aim of the study was to asses the influence of short-term mechanical ventilation with heliumoxygen mixture (heliox) in newborns with MAS on basic vital signs, oxygenation, acid-base balance and respiratory mechanics.The study was carried out in newborns with respiratory failure requiring mechanical ventilation due to MAS. Patients were ventilated using PC-SIMV. Parameters of mechanical ventilation, respiratory mechanics, oxygenation, acid-base balance and vital signs were recorded during three periods of one hour before, during and after heliox ventilation.Nine newborns with MAS were enrolled in the study. Mechanical ventilation with heliox did not affect vital signs, and infants' general condition remained stable during and after ventilation with heliox. Mechanical ventilation with heliox was associated with a statistically significant increase in dynamic compliance(mean 0,4 vs 0,53ml/cmH2O). Heliox caused an increase in tidal volume(mean 5,57 vs 6,84ml/kg)and minute ventilation(mean 0,87 vs 0,95l)but this was not statistically significant. Mechanical ventilation with heliox allowed the use of significantly lower fractions of inspired oxygen(mean 0,62 vs 0,35), with a significant decrease in the oxygenation index(mean 8,09 vs 4,26)and alveolararterial oxygen tension difference(mean 320,04 vs 127,65mmHg).A significant increase in pH(mean 7,34 vs 7,38) was also observed with a concomitant decrease in PaCO2(mean 43,4 vs 39,9)which was not statistically significant. Beneficial effects of heliox reversed after ventilation with this gas mixture was stopped. Patients required higher FiO2(mean 0,35 vs 0,38), OI(mean 4,26 vs 5,27)and AaDO2(mean 127,65 vs 159,6)increased. There was also a significant decrease in oxygen saturation(mean 93,69 vs 91,63).Ventilation with heliox had a positive effect on the selected parameters of oxygenation, acid-base balance and respiratory mechanics in newborns with MAS.

Acid-base balance parameters and a value of anion gap of arterial and venous blood in Małopolski horses

The comparative study of the acid-base balance (ABB) parameters has been performed on 20 clinically healthy mature Małopolski horses. An arterial blood sample from the facial artery and a sample of venous blood from the external cervical vein were colected from each animal. In the samples tested, the blood pH, pCO2, tCO2, HCO3-, concentration of Na+, K+, Cl-, and a value of the anion gap were determined. The difference among pCO2, tCO2, and HCO3- in both samples tested was statistically significant, whereas the pH of the arterial blood and the pH of the venous blood did not differ significantly. The anion gap in both types of blood did not differ significantly. 1) ABB parameters such as pCO2, HCO3-, and tCO2 determined in the arterial and venous blood of the Małopolski horses differ from each other significantly. 2) In spite of the lack of the differences between pH of the arterial and venous blood, the ABB parameters in horses should be determined in the arterial blood, because the comparative study performed proves that the analysis of the ABB parameters determined for the venous blood of a healthy horse may lead to a wrong diagnosis of the compensated respiratory acidosis. 3) The mean value of anion gap in horses aged 8-12 years amounts to 20.9 mmol/l for the arterial blood and 19.93 for the venous blood; the difference between the two values is not statistically significant.

Outcome of severe lactic acidosis associated with metformin accumulation

IntroductionMetformin associated lactic acidosis (MALA) may complicate metformin therapy, particularly if metformin accumulates due to renal dysfunction. Profound lactic acidosis (LA) generally predicts poor outcome. We aimed to determine if MALA differs in outcome from LA of other origin (LAOO).MethodsWe conducted a retrospective analysis of all patients admitted with LA to our medical ICU of a tertiary referral center during a 5-year period. MALA patients and LAOO patients were compared with respect to parameters of acid-base balance, serum creatinine, hospital outcome, Simplified Acute Physiology Score II (SAPS II) and Sequential Organ Failure Assessment (SOFA) score, using Pearson's Chi-square or the Mann-Whitney U-test.ResultsOf 197 patients admitted with LA, 10 had been diagnosed with MALA. With MALA, median arterial blood pH was significantly lower (6.78 [range 6.5 to 6.94]) and serum lactate significantly higher (18.7 ± 5.3 mmol/L) than with LAOO (pH 7.20 [range 6.46 to 7.35], mean serum lactate 11.2 ± 6.1 mmol/L). Overall mortality, however, was comparable (MALA 50%, LAOO 74%). Furthermore, survival of patients with arterial blood pH < 7.00 (N = 41) was significantly better (50% vs. 0%) if MALA (N = 10) was the underlying condition compared to LAOO (N = 31).ConclusionsCompared to similarly severe lactic acidosis of other origin, the prognosis of MALA is significantly better. MALA should be considered in metformin-treated patients presenting with lactic acidosis.

Lipid peroxidation and biochemical parameters in umbilical cord blood of well-adapted term newborns

Lipid peroxidation (LPX) can play an important role in the development of pathological changes of foetal and neonatal tissues. We investigated LPX and biochemical parameters in plasma from mixed umbilical cord (m.u.c.) blood and acid-base balance (ABB) parameters in m.u.c. blood of well-adapted full-term newborns. LPX products were estimated as thiobarbituric acid reacting substances (TBARS) and were expressed by using of malondialdehyde (MDA) as a standard solution. Intensity of LPX was estimated in vitro in m.u.c. blood plasma without and with added LPX activator (125 μM L-ascorbate plus 5 μM FeSO4) and in the incubated plasma (30 min, 37°C) under both conditions. Actual TBARS (3.51 ± 0.49 nmol/mL) were determined in the non-incubated plasma without the added LPX activator. Approximately twice higher TBARS were found in the incubated plasma without the LPX activator (7.29 ± 2.17 nmol/mL) or with it (8.57 ± 2.20 nmol/mL), as well as in the non-incubated plasma after its addition (7.38 ± 1.98 nmol/mL). All analysed biochemical parameters (Fe, total iron-binding capacity, uric acid, proteins, Mg, Ca, phosphate, glucose, K, Na, Cl, ALT, AST, GMT, CK, LD, HBD, AMS, ALP, ACP) and ABB parameters were within their reference ranges. The actual TBARS levels were found being positively correlated with α-hydroxybutyrate dehydrogenase (HBD) activity and negatively with pO2. These results suggest that LPX in m.u.c. blood plasma might be activated. This activation could probably depend on extent of hypoxia. TBARS and their formation in vitro could be suitable parameters of LPX in m.u.c. blood.

Mitochondrial DNA Haplogroups and Highly Active Antiretroviral Therapy–Related Lipodystrophy

The combination of different point mutations in mitochondrial DNA (mtDNA), which are defined as haplogroups, may cause modification in organelle function and may be involved in several pathologies. We analyzed the distribution of mtDNA polymorphisms in human immunodeficiency virus (HIV)-infected patients with lipodystrophy, a relevant adverse event caused by highly active antiretroviral therapy, and their correlation with metabolic and viroimmunologic parameters. The frequency of the 9 most common European haplogroups was investigated in 346 white, HIV-infected patients with lipodystrophy. Haplogroups were identified on the basis of classic methods. Statistical analysis was performed with use of 1-way analysis of variance, the chi(2) test, and principal-components analysis. The distribution of mtDNA haplogroups among patients with lipodystrophy was similar to that among the general European population. We found no differences between patients with different haplogroups with regard to viroimmunologic results (plasma HIV load, CD4(+) T cell count, and nadir CD4(+) T cell count), glucose data (glucose, insulin, C-peptide, and glycosylated hemoglobin concentrations and insulin resistance), lipid data (levels of triglycerides, total cholesterol, high- and low-density lipoproteins, and apolipoprotein A1 and B), acid-base balance parameters (lactate level and anion gap), or anthropometric measures (weight, body mass index, and waist-to-hip ratio). No differences were observed in trunk fat levels, leg-fat ratio (which was determined by dual-energy x-ray absorptiometry), or exposure to different drug classes. Principal-components analysis confirmed that the spatial distribution of patients belonging to a given haplogroup was not influenced by different clinical parameters. Our study indicates that, in HIV-infected patients with lipodystrophy, mtDNA haplogroups are not related to major metabolic changes or to particular viroimmunologic features.

Hemogasometria de eqüinos submetidos à obstrução experimental do duodeno, íleo e cólon maior

Visando estudar os parâmetros do equilíbrio ácido-base de eqüinos submetidos a um modelo experimental de obstrução intestinal, 24 animais foram distribuídos em quatro grupos, controle instrumentado (GI), obstrução do duodeno (GII), íleo (GIII) e cólon maior (GIV). As amostras de sangue venoso foram coletadas antes das cirurgias (T0), durante as obstruções (T30ob-T180ob) e após as desobstruções (T60des-T180des). Os eqüinos do GIV, no T30ob, e os eqüinos do GII, nos T60ob, T90ob e T120ob, apresentaram aumento do pH(v), da cHCO-3(vP) e da cBase(v) que, acrescidos do aumento da pCO2(v) e da ctCO2(v), caracterizou a alcalose metabólica com compensação respiratória. Nos T90ob e T120ob, nos animais do GII, e no T180ob, nos animais do GIII, a pO2(v) e a sO2(v) tiveram comportamento semelhante. Os valores baixos apresentados pelos animais do GII foram associados à hipercapnia ou à hipoventilação, desencadeadas para a correção da alcalose metabólica. Entretanto, a hipoxemia apresentada pelos animais do GIII foi associada à hipovolemia presente neste período. As alterações ácido-base observadas constituem-se de alterações leves e temporárias, as quais não são capazes de predizer o diagnóstico das obstruções intestinais específicas em eqüinos com cólica. Entretanto, por relacionarem-se diretamente com a precocidade do distúrbio gastrintestinal, elas auxiliam o pesquisador no prognóstico.

Prolonged Thoracic Epidural Anesthesia in the Correction of Hypoxia in the Postoperative Period

Objective: to reduce the incidence of postoperative complications after high-risk abdominal surgery. Subjects and methods. The study enrolled 69 patients undergoing operations on the upper abdomen. The patients were randomized into 2 groups: 1) those who received total intravenous anesthesia with prolonged thoracic epidural anesthesia (a study group); 2) those who had total intravenous anesthesia with postoperative analgesia with promedol and ketorolac (a control group). The course of anesthesia and the period of early postanasthesia adaptation, the quality of postoperative analgesia and the parameters of external respiratory function, acid-base balance, and gas composition in the arterial blood were studied; the pattern of postoperative complications was also analyzed. Results. Epidural anesthesia considerably reduced the consumption of narcotic analgesics and myorelaxants at surgery, which was followed by the accelerated early postanesthesia adaptation of patients. Postoperative analgesia adequacy was much higher in the study group patients. Postoperatively, there were significant external respiratory dysfunctions of the restrictive type in both groups; however, they were much less pronounced in the study group. In the postoperative period, the control patients were observed to have significant and persistent hypoxemia, presumably associated with the development of microatelectases. There was a reduction in the incidence of respiratory and surgical complications in the study group. Conclusion. Prolonged epidural anesthesia versus anesthesia with narcotic analgesics used during high-risk abdominal surgery accelerates early postanesthesia adaptation and ensures a more adequate postoperative analgesia, resulting in a reduction in the severity of external respiratory dysfunction and impaired blood gas composition, by leading to a decrease in the incidence of postoperative complications. Key words: epidural anesthesia, surgery, external respiratory function, hypoxemia, complications.

Changes in Acid-Base Balance and Related Physiological Responses as a Result of External Hypercapnia During the Second Half of Incubation in the Chicken Embryo

This study investigated the effect of high CO2 (4%) from embryonic day (ED)10 until ED16 on the acid-base balance and related parameters in the chicken embryo. From ED10 to ED16, blood was taken from a vein from the chorioallantois membrane and was analyzed for pH, partial pressure of CO2, partial pressure of O2 (pO2), [HCO3(-)], [K+], and [Ca2+]. Allantoic fluid was taken for measurement of pH, NH3-N, phosphate, and calcium concentration. The right tibia was ashed, and calcium was measured with atomic absorption spectroscopy. Embryos exposed to high CO2 showed a consistent higher blood pH than control embryos. Notwithstanding this alkalosis, bicarbonate concentration was significantly higher in the CO2 group from ED12 until ED16. Potassium concentration in the blood was significantly higher in the CO2 group from ED11 until ED16. The pH of the allantois was significantly higher on ED14 and ED15. Ammonia N concentration was significantly higher in the CO2-incubated embryos on ED12 and ED13, whereas phosphate did not differ between groups. Calcium per tibia dry weight did not differ between incubation conditions. We can conclude that embryos adapt to high CO2 during the second half of incubation by increasing blood HCO3(-). It appears that this increase in HCO3(-)is mainly the result of the stimulated intracellular exchange of H+ with K+, although temporary reabsorption of HCO3(-)by the kidney cannot be excluded.

The impact of dietary cation anion difference (DCAD) on the acid-base balance and calcium metabolism of non-lactating, non-pregnant dairy cows fed equal amounts of different anionic salts

We evaluated the impact of the dietary cation-anion difference (DCAD) on the influence of anionic salts (AS) on the metabolism of dairy cows using a study-design that included control of feed intake. Ten mature, non-lactating, non-pregnant, Holstein-Friesian-crossbreed cows received 2000 mEq of either one of the seven anionic salts tested, two combinations of the anionic salts or water as control via a rumen cannula. Salts and controls were assigned in a 10x10 Latin square design. Whole blood, serum and urine samples were taken during treatment (TP) and washout period. Samples of whole blood were tested for pH, base-excess and bicarbonate concentrations. In urine, pH and net acid-base excretion (NABE) were analysed. Calcium was measured in serum and urine. According to the different batches of hay, five groups of DCAD were created regarding cluster analysis. Changes in urine and blood parameters were statistically analysed for each DCAD group separately. The different DCAD had an impact on the amount of change in acid-base balance (ABB) and calcium metabolism and for how long these changes lasted. In the DCAD group receiving the highest amount of AS (239 mEq/kg dry matter with AS), changes of ABB were only noticeable in urine and these changes only differed from day zero in the first week of TP (P<0.05). In the other four groups changes of ABB were also visible in blood parameters, but only on a few days of TP did the deviations differ significantly (P<0.05) from day zero. Changes of ABB parameters in urine samples were more pronounced than those in blood and differed clearly from day zero (P<0.05). Parallel to the changes of ABB, calcium concentrations in these samples were significantly increased (P<0.001) in all DCAD groups. Except for the highest DCAD group, ionized calcium concentrations changed over time (P<0.020). However, the differences were very small and only differed from day zero on a few TP days. We conclude that the DCAD of a dairy cow's diet has an important impact on the effect of AS on ABB and calcium metabolism with respect to the duration and amount of change. The target regions of DCAD should be clearly below 100 mEq/kg dry matter to ensure the desired effect on ABB and calcium metabolism. Extremely negative DCAD should be avoided to minimize the risk of clinical acidosis induced by AS.

Surfactant BL-Induced Changes in Blood Gas Composition and Acid-Base Balance In Neonatal Respiratory Distress Syndrome

The paper presents the results of a study of blood gas composition and acid-base balance (ABB) in the use of the Russian drug Surfactant BL in preterm neonatal infants with respiratory distress syndrome (RDS). The surfactant was given to 57 preterm neonates. A control group consisted of 52 children with RDS who had received a course of treatment before the use of the drug in the hospital. Statistical analysis indicated the virtual similarity of the study and control groups. The study demonstrated that that in Surfactant BL-treated patients, blood oxygenation (pO2, %SO2c, A-a DO2, respiratory coefficient) improved much more rapidly and the mean values of these parameters remained statistically significantly better from the end of 24 hours of treatment than in the control neonates up to the end of therapy in the intensive care unit of the maternity hospital. Studies of blood ABB showed that the neonates of both groups had moderate metabolic acidosis at the initiation of therapy. With the therapy performed, the parameters of ABB generally reached normal values within the first 24 hours of therapy. There were no obvious differences in the changes of blood ABB parameters in the neonatal infants of both groups. Analysis of the results of treatment in neonates with ABB showed a statistically significant advantage in terms of positive outcomes of treatment in the group of Surfactant BL-treated patients.