Acid-base Balance In Patients Research Articles

Кислотно-щелочное состояние крови у пациентов с мочекаменной болезнью. Исследование I: роль бикарбонатов.

Introduction. Kidneys play a leading role in maintaining acid-base balance. Kidney disorders lead to the acid-base balance violations. Data analysis showed that there are not enough attention to the problem of assessing blood acid-base balance in patients with urolithiasis. The aim of the first stage of this work was to determine the presence and severity of changes in one of the main indicators of acid-base balance - the level of blood bicarbonate in patients with urolithiasis. Materials and methods. We analyzed data from 83 patients: 39 men and 44 women aged 18 to 74 years. All patients were prescribed a biochemical blood test, a biochemical analysis of daily urine, blood acid-base balance and stone chemical composition. We studied the relationship of actual serum bicarbonate (actHCO3 - ) and standard bicarbonate (stdHCO3- ) in urolithiasis patients with level of other blood and urine parameters. Statistical analysis was performed using the methods of descriptive statistics, comparative statistical analysis, calculation of the t-test for independent groups, correlation analysis for two variables using the computer program Statistica 10.0 (StatSoft USA). Results. According to the statistical analysis performed using the calculation of Student's t-test, patients with actual serum bicarbonate [actHCO3- ] <21.0 mmol/l and urine pH>5.8 had lower serum total calcium levels (p<0.05 ), higher serum [Cl-] (p<0.05), higher serum creatinine (p<0.05) and urea (p<0.05), lower serum pH (p<0, 05), serum pCO2 (p<0.05), serum lactate concentration (p<0.05), lower BE (p<0.05) than patients with [actHCO3- ] blood >28.0 mmol/l. Correlation analysis showed that there is a relationship between the level of [actHCO3- ] and indicators of total blood calcium (p <0.05), blood chloride (p<0.05), creatinine and blood urea (p <0.05) and the concentration of calcium and magnesium in the daily urine (p<0.05). There was no statistically confirmed relationship between the level of standard blood bicarbonate [stdHCO3- ] and the concentration of other indicators of blood and daily urine. Conclusion. Determination of the serum bicarbonate level is necessary to clarify the metabolic state in urolithiasis patients. It is necessary to determine the concentration of actual blood bicarbonate (actHCO3- ) in urolithiasis patients.

#3853 THE EFFECT OF PERITONEAL CAVITY FLUSHING ON ACID BASE BALANCE OF PERITONEAL DIALYSIS PATIENTS

Abstract Background and Aims Flushing peritoneal cavity with dialysis fluid with short time dwells it is a necessity in some cases for peritoneal dialysis patients. Such cases are overhydration with pulmonary congestion or peritonitis before the initiation of antibiotic treatment as an effort to reduce pain. The aim of this study was to investigate the effect of frequent exchanges with peritoneal dialysis (PD) fluid with bicarbonate as a buffer on acid base balance of peritoneal dialysis patients. Method This is a single center cohort study of 18 stable PD patients (m=10.f=8). Their median age was 57 (47, 71) years, their median PD duration was 33 (16, 89) months and they all fulfill the criteria for achieving adequacy targets [median Kt/V 2.17 (1.99, 3.3)] with good nutrition markers [ median albumin levels 3.9 (3.6, 4) gr/dl]. A sample of arterial blood gas (ABG) was taken from the patients before the procedure and after full drainage of the peritoneal cavity . The procedure included 4 times flushing of 1000 ml of dialysis fluid remaining for15 minutes In the peritoneal cavity each time . At the end of the procedure a new blood sample for ABG was taken. We used PD solution with bicarbonate as a buffer (34 mmol/Lt). We estimated the alterations of pH, of bicarbonate (HCO3-), of pCO2, of Base Excess(ΒΕ), of ionized calcium (iCa++) and lactate (Lac) Results Using the non parametric related samples Wilcoxon signed method we found a statistically significant increase in arterial HCO3- concentration between the values before and after the procedure [HCO3-before:25.4 (22, 28), HCO3after:26.5 (24, 29) mEq/lt-P = .023]. Likewise there was a statistically significant increase in BE with median values before the procedure 1 (-1.2,2.9) and after the flushing 2 (-0.6,3,8), P = .018. Even though there was a statistically significant increase in the bases expression of the acid base balance of the patients there wasn't any statistically significant alterations in pH levels- i.e. Alkalemia (pHbefore=7.41,pHafter=7.42 – P = .35) or pCO2 levels i.e. Compensatory Respiratory Acidosis (pCO2προ=40, pCO2μετα=40 – P = .179) nor to the levels of ionized calcium Conclusion Flushing of peritoneal cavity using peritoneal dialysis solution with bicarbonate as a buffer is safe and in this study was not correlated with the development of metabolic alkalosis

Regulation of Acid-Base Balance in Patients With Chronic Kidney Disease.

Normallly the kidneys handle the daily acid load arising from net endogenous acid production from the metabolism of ingested animal protein (acid) and vegetables (base). With chronic kidney disease, reduced acid excretion by the kidneys is primarily due to reduced ammonium excretion such that when acid excertion falls below acid porduction, acid accumulation occurs. With even mild reductions in glomerular filtration rate (60 to 90 ml/min), net acid excretion may fall below net acid production resulting in acid retention which may be initially sequestered in interstitial compartments in the kidneys, bones, and muscles resulting in no fall in measured systemic bicarbonate levels (eubicarbonatemic metabolic acidosis). With greater reductions in kidney function, the greater quantities of acid retained spillover systemically resulting in low pH (overt metabolic acidosis). The evaluation of acid-base balance in patients with CKD is complicated by the heterogeneity of clinical acid-base disorders and by the eubicarbonatemic nature of the early phase of acid retention. If supported by more extensive studies, blood gas analyses to confirm the acid-base disorder and newer ways for assessing the presence of acidosis such as urinary citrate measurements may become routine tools to evaluate and treat acid-base disorders in individuals with CKD.

Results of assessment of oral acid-base balance in patients with mandibular fractures combined with periodontal pathology

Aim. To estimate the condition of acid-main balance of oral cavity in patients with fracture of the mandible in combination with parodontal pathology.Material and methods. 40 patients with fractures of the mandible in combination with parodontal pathology were observed in the study. They were divided into three groups. Patients of the first group had a fracture of the mandible in combination with chronic periodontitis. Patients of the second group had fractures of the mandible and chronic gingivitis. Patients of the third group had no bone-traumatic damages and parodontal pathology.Results and discussion. The activity of the parodontal microflora of the oral cavity in patients with the bone trauma of the mandible in combination with periodontitis is higher and characterizes the quick response component of the acid-main balance regulation in the oral cavity.Conclusion. Lingual raid is the main reservoir of oral microflora and its role under existing bone-traumatic damage on the background of parodontal pathology in maintaining microbiocenosis not only increases but also becomes the factor of destabilization regenerators processes at fracture of the mandible.

Study on Acid-Base Balance Disorders and the Relationship Between Its Parameters and Creatinine Clearance in Patients with Chronic Renal Failure

Objectives: We aimed to determine the parameters of acid-base balance in patients with chronic renal failure (CRF) and the relationship between the parameters evaluating acid-base balance and creatinine clearance. Methods: The current cross-sectional study was conducted on 300 patients with CRF (180 males and 120 females). Clinical examination and blood tests by taking an arterial blood sample for blood gas measurement as well as venous blood for biochemical tests to select study participants were performed. Results: Patients with CRF in the metabolic acidosis group accounted for 74%, other types of disorders were less common. The average pH, PCO₂, HCO₃, tCO₂ and BE of the patient group were 7.35 ± 0.09, 34.28 ± 6.92 mmHg, 20.18 ± 6.06 mmol/L, 21.47 ± 6.48 mmHg and -4.72 ± 6.61 mmol/L respectively. These parameters are lower than normal values and decrease by progressing chronic kidney disease (CKD) stage. These parameters correlated moderately with creatinine clearance. Conclusions: In patients with CRF, metabolic acidosis is predominant, and acid-base balance parameters are positively correlated with creatinine clearance.

Comparative analysis of acid-base balance in patients with severe sepsis and septic shock: traditional approach vs. physicochemical approach

Introduction: The evaluation of metabolism and the diagnostic classification of acid-base disorders has generated great controversy. Acid-base balance (ABB) is approached by means of the physicochemical and Henderson’s models.Objective: To compare two diagnostic approaches to ABB in patients with severe sepsis.Materials and methods: Prospective, descriptive study conducted in patients with severe sepsis. ABB was analyzed within the first 24 hours. The diagnosis was compared according to each model and the causes of the disorders were compared according to the physicochemical model.Results: 38 patients were included in the study, of which 21 (55%) were women; the mean age was 49 years, the median APACHE II, 13.28, and the mortality at 28 days, 24.3%. The traditional approach identified 8 patients with normal ABB, 20 with metabolic acidosis, and 10 with other disorders. Based on the physicochemical model, all subjects had acidosis and metabolic alkalosis. Increased strong ion difference (SID) was the most frequently observed disorder.Conclusion: The physicochemical model was useful to diagnose more patients with acid-base disorders. According to these results, all cases presented with acidosis and metabolic alkalosis; the most frequent proposed mechanism of acidosis was elevated SID. The nature of these disorders and their clinical relevance is yet to be established.

A study on effect of lactate versus acetate-based intravenous fluids on acid-base balance in patients undergoing free flap reconstructive surgeries in India

A study on effect of lactate versus acetate-based intravenous fluids on acid-base balance in patients undergoing free flap reconstructive surgeries in India

Arterial blood gas and acid-base balance in patients with pregnancy-induced hypertension syndrome.

This study aimed to investigate the expression of arterial blood gas and acid-base balance in patients with pregnancy-induced hypertension syndrome and their influence on newborns. A total of 348 patients with pregnancy-induced hypertension syndrome (research group) admitted and treated in the First People's Hospital of Jining from March 2013 to March 2016 were retrospectively analyzed, and another 156 cases of healthy pregnant women who were physically examined were selected as the control group. Blood gas analysis was performed on pregnant women, and pH value, partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), bicarbonate radical (HCO3−) and base excess (BE) were included as test indexes. Apgar score was made for newborns for neonatal asphyxia. The evaluation was performed at 1, 5, and 10 min after birth to analyze the correlation between the maternal arterial blood pH and the neonatal Apgar score. The pH value, and PO2 and HCO3− levels in the research group were lower than those in the control group (p<0.05). PCO2 and BE levels in the research group were higher than those in the control group (p<0.05). The incidence of neonatal mild asphyxia (Apgar score, 4–6 points) and neonatal severe asphyxia (Apgar score, <4 points) in the research group were higher than that in the control group (p<0.05). The Apgar score of newborns was positively correlated with the pH value of the arterial blood of pregnant women. Blood gas analysis in patients with pregnancy-induced hypertension syndrome is useful to a certain extent to evaluate the condition of the patient. The combination of the pH value of the patient and the Apgar score of the newborns may help improve the judgement rate of neonatal asphyxia so as to improve the quality of childbirth by early monitoring and intervention of the newborns.

Effect of lactate versus acetate-based intravenous fluids on acid-base balance in patients undergoing free flap reconstructive surgeries.

Background and Aims:Use of lactated intravenous fluids during long surgeries could cause lactate accumulation and lactic acidosis. Acetate-based solutions could be advantageous as they are devoid of lactate. The primary aim of the study was to assess the effect of use of an acetated solution or Ringer's lactate (RL) as intraoperative fluid on lactate levels in patients without hepatic dysfunction undergoing prolonged surgeries.Material and Methods:This was a prospective, randomized, controlled trial involving sixty patients belonging to American Society of Anesthesiologists Physical Status I to II undergoing major head and neck surgeries with free flap reconstruction. Patients were randomly allocated into two equal groups, Group sterofundin (SF) and Group RL. Group SF was started on acetate-based crystalloid solution (sterofundin B Braun®) and Group RL received RL intravenously at the rate of 10 ml/kg/h to maintain systolic blood pressure above 90 mmHg. Blood loss >20% was replaced with packed cells. Arterial blood gas analysis was done 2nd hourly till 8 h. Chi-square test was used to compare categorical variables. Independent sample t-test was used to compare means.Results:Intraoperative lactate levels were significantly high in RL group at 2, 4, 6, and 8 h. The pH was comparable between groups except at 8 h where RL group had a significantly lower pH than SF group (7.42 ± 0.1 vs. 7.4 ± 0.1). Sodium, potassium, chloride, bicarbonate, and pCO2did not show any significant difference between the groups.Conclusion:Use of acetate-based intravenous solutions reduced levels of lactate in comparison with RL in patients undergoing free flap reconstructive surgeries.

Стан кислотно-основної рівноваги у хворих на цироз печінки: роль у патоґенезі ураження дихальної системи; залежність від ступеня ураження печінки за C. G. Child - R. N. Pugh

Стан кислотно-основної рівноваги у хворих на цироз печінки: роль у патоґенезі ураження дихальної системи; залежність від ступеня ураження печінки за C. G. Child - R. N. Pugh

Effects of Parenteral Infusion of Amino Acid Solutions in Acid-Base Balance in Patients with Advanced Chronic Renal Failure

Malnutrition is a very common condition in patients with chronic kidney disease (CKD), especially after the 3rd stage (GFR 30-59 mL/min/1.73 m2). It affects virtually every organ and the function of the entire organism as well and therefore influences the survival. Moreover, the supplementation of amino acids could correct the negative nitrogen balance of those patients improving their survival rates, while little is known regarding any possible negative effect of this supplementation of amino acids on the acid-base balance. We investigated the impact of parenteral infusion of two different kinds of amino acid solutions (specific for CKD patients and nonspecific) in 25 patients (12F, 13M), suffered from chronic renal failure in stages 3 and 4 (GFR 16 to 45.1 mL/min/1.73 m2). The specific for uremic CKD patients solution A was administrated for 5 days, and after an interval of one week, we treated the same patients for another 5 days with the second non-specific solution B, with usual composition), in order to investigate their influence on patients’ acid-base balance. Comparing the results of the first and the last infusion of solution A, neither pH nor blood gases analysis presented significant differences, while solution B induced statistically significant changes in both pH and blood gases, (p=0.0001). Acidosis was resulted in by the reduction of serum levels of HCO3 - whereas not any significant change observed in serum lactate levels after the infusion of each solution. These results suggest that for patients with chronic kidney disease in stages 3 and 4 who require the administration of a supplementary amino acid solution, the CKD-specific solution A may be preferred, since it prevents the worsen of the metabolic acidosis, which is commonly present in these patients.

Prognostic Impact of Clinical Scenarios (CS) and Acid-Base Balance in Patients with Acute Heart Failure

Backgrounds: Blood gas analysis is usually performed during the treatment of patients with acute heart failure (AHF) in the emergency setting. However, the roles of acid-base balance in AHF remain unclear. We therefore investigated the relationship between acid-base balance, clinical scenarios (CS) and prognosis in patients with AHF. Methods: Two-hundred eighty-five patients with AHF who were admitted to the intensive care unit between March 2006 and September 2010 were enrolled. We examined the relationship between systolic blood pressure (SBP) and acid-balance.

Regional citrate anticoagulation in patients with liver failure supported by a molecular adsorbent recirculating system*

Regional citrate anticoagulation has emerged as a promising method in critically ill patients at high risk of bleeding. However, in patients with liver failure, citrate accumulation may lead to acid-base and electrolyte imbalances, notably of calcium. The aim of this study was to evaluate the feasibility and safety of regional citrate anticoagulation during liver support using a molecular adsorbent recirculating system as well as its effects on electrolyte and acid-base balance in patients with liver failure. Prospective observational study. University hospital. Twenty critically ill patients supported by molecular adsorbent recirculating system resulting from liver failure between January 2007 and May 2009. The median duration of molecular adsorbent recirculating system treatment was 20 hrs (interquartile range, 18-22 hrs). Two of 77 molecular adsorbent recirculating system treatments (2%) were prematurely discontinued as a result of filter clotting and bleeding, respectively. The median citrate infusion rate, necessary to maintain the postfilter ionized calcium between 0.2 and 0.4 mmol/L, was 3.1 mmol/L (interquartile range, 2.3-4 mmol/L) blood flow. The median calcium chloride substitution rate was 0.9 mmol/L (0.3-1.7 mmol/L) dialysate. Total serum calcium remained stable during molecular adsorbent recirculating system treatments. There was a statistically significant increase of the ratio of total calcium to systemic ionized calcium (2.04 ± 0.32 mmol/L to 2.17 ± 0.35; p = .01), which reflected citrate accumulation resulting from liver failure. Under close monitoring, no clinically relevant electrolytes or acid-base disorders were observed. Our results suggest that regional citrate anticoagulation is a safe and feasible method to maintain adequate circuit lifespan without increasing the risk of hemorrhagic complications while maintaining a normal acid-base as well as electrolyte balance in patients with liver failure supported by molecular adsorbent recirculating system.

Switching from Three Times a Week to Short Daily Online Hemodiafiltration: Effects on Acid-Base Balance

This study examines the effect of a change from the standard 4-5 hours 3 times a week of online hemodiafiltration (OL-HDF) to 2-2.5 hours daily (6 times a week) OL-HDF, on acid-base balance, and attempts assess the modifications of acid-base parameters, ionic concentration, and electrical charges of albumin and phosphate available for diffusion and convection mechanisms across the membrane and subsequent infusion. In 18 patients on online HDF, blood gas, electrolytes (Na, K, Cl), lactate, phosphate, albumin, apparent strong ion difference (SIDa), effective strong ion difference (SIDe), strong ion gap (SIG), anion gap (AG), and bicarbonate and pH time-averaged concentration (TAC) and time-averaged deviation (TAD) variables were evaluated at baseline, and 1, 3, 6, 9, and 12 months after patients were switched to daily OL-HDF. Additionally, in 12 patients, the same parameters measured simultaneously at dialyzer inlet, outlet, and after reinfusion were studied. Throughout the study, weekly single-pool Kt/V, equilibrated Kt/V, and TAC urea remained constant. However, standard Kt/V increased and TAD urea decreased on daily OL-HDF. There were no statistical differences during the time span of 12 months in pH, cations (Na, K), anions (Cl, HCO3(-) AG, and lactate), or SIDa, SIDe, and SIG pre-HDF; while pH and HCO3(-) TAD decreased from 0.02 and 1.02 +/- 0.74 mEq/L, to 0.01 and 0.64 +/- 0.52 mEq/L, respectively (p<0.01). Net albumin charge and AG increased significantly at dialyzer outlet and decreased after reinfusion. We did not observe changes in the acid-base balance in patients who switched from 3 times a week to short daily OL-HDF. The main benefit observed was a lower pH and bicarbonate TAD. This shows a better physiology for daily OL-HDF.

ECOLOGICAL STRESS AND ITS EFFECTS ON ESSENTIAL HYPERTENSION AND CHRONIC OBSTRUCTIVE BRONCHITIS DEVELOPMENT IN ROSTOV-ON-DON INHABITANTS

Aim. To study prevalence of essential hypertension (HT) and chronic obstructive bronchitis (COB) among Rostov-on-Don population, to assess influence of ecological stress on HT and COB development and to find the ways to improve therapy of combined pathology. Material and methods. Single-stage epidemiologic study of Rostov-on-Don population was carried out. The study included questionnaire to reveal main risk factors of chronic noninfectious diseases, a number of laboratory and instrumental indices. Results. Prevalence of HT and COB is significantly higher in patients, living in ecologically unfavorable districts. Rigidity and stretch ability of vascular wall influence the course and development of HT as well as atrial natriuretic factor. Carbonic anhydrase inhibitor, acetazolamide, when is added to standard therapy increases in its efficacy in blood pressure control, decrease in blood pressure in pulmonary artery and correction of disturbed acidbase balance in patients with HT combined with COB. Conclusion. The connection between unfavorable ecology and HT and COB development is demonstrated. Adjuvant therapy with acetazolamide is proposed to increase in efficacy of HT and COB standard therapy.

Characteristics of acid-base balance in patients with chronic severe hepatitis: analysis of 126 cases

To investigate the characteristics of acid-base balance in patients with chronic severe hepatitis. Samples of venous blood and arterial blood were collected from 126 patients with chronic severe hepatitis, 106 males and 20 females, aged 44 +/- 13 (25 - 74), to undergo measurement of the potassium, sodium, and chloride ions, and urea nitrogen and creatine, blood electrolytes and blood gas analysis respectively. Acid-base disturbance (ABD) was found in 115 of the 126 patients (91.3%). 40 of the 115 patients with ABD (31.7%) had respiratory alkalosis combined with metabolic alkalosis, 32 of them (25.4%) had respiratory alkalosis combined with metabolic acidosis; 28 of them (22.2%) had pure respiratory alkalosis, and 8 (6.3%) had pure metabolic acidosis. Five patients had triple acid-base disturbance, 4 of which had respiratory alkalosis (combined with metabolic alkalosis and metabolic acidosis, 3.2%), and 1 of which had respiratory acidosis (combined with metabolic alkalosis and metabolic acidosis, 0.8%). There was no significantly difference in the prevalence rates of pure acid-base disturbance and multiple acid-base disturbances between the patients with cirrhosis-base chronic severe hepatitis and those with chronic hepatitis-based chronic severe hepatitis. Hypoxia symptoms were seen in 34 patients (27%). 103 patients died. All the 15 patients with their blood pH < 7.35 died. ABD in the patients with chronic severe hepatitis is mainly alkalosis with respiratory alkalosis as the basic ABD type. The appearance of ABD is not associated with the underlying illness. Patients of chronic severe hepatitis often suffer from hypoxia. Low blood pH is an important factor causing death.

Acid-Base Balance during Continuous Veno-Venous Hemofiltration: The Impact of Severe Hepatic Failure

Continuous renal replacement therapy (CRRT) affects acid-base balance but the influence of severe hepatic failure (SHF) on this effect is unknown. To assess the effect of SHF on acid-base balance in patients receiving CVVH. Retrospective laboratory investigation. Forty patients with SHF and acute renal failure (ARF) treated with CVVH and 42 critically ill patients with severe ARF but no liver disease also treated with CVVH (controls). Retrieval of clinical and laboratory data from prospective unit and laboratory databases. Quantitative acid-base status assessment using the Stewart-Figge methodology. Comparison of findings between the two groups. Although CVVH had a major effect on acid base balance in both groups, patients with SHF had a higher mean lactate concentrations (4.8 vs. 3.1 mmol/L; p<0.0005), a greater base deficit compared to controls (-1 vs. 4.1 mEq/L; p<0.0001) and a lower PaCO 2 tension (36.8 vs. 42.5 mmHg; p<0.0001), despite the use of bicarbonate replacement fluid. The acidifying effect of hyperlactatemia was slightly worsened by an increased strong ion gap (9.3 vs. 4.9 mEq/L; p<0.0001). It was, however, attenuated by an increased strong ion difference apparent (SIDa) (43.6 vs. 41.9 mEq/L; p<0.05) secondary to hypochloremia (96 vs. 100 mmol/L; p<0.0001) and by hypoalbuminemia, although hypoalbuminemia in SHF patients (26 vs. 23; p<0.005) was less pronounced than in controls. The use of CVVH does not fully correct the independent acidifying effect of liver failure on acid-base status. Increased lactate and strong ion gap values maintain a persistent base deficit despite the alkalinizing effects of hypoalbuminemia and hypochloremia. The correction of acidosis in SHF patients may require more intensive CVVH.

Effect of hypertonic saline dextran on acid-base balance in patients undergoing surgery of abdominal aortic aneurysm*

To evaluate the magnitude and cause of metabolic acidosis after infusion of 7.5% sodium chloride 6% dextran 70. Randomized, prospective clinical study. University hospital. Two groups of 14 patients each, undergoing repair of abdominal aortic aneurysm. Patients were randomly assigned to receive either 250 mL of hypertonic saline dextran (HSD) or a conventional fluid regimen with 250 mL of hydroxyethyl starch in normal saline solution (H-NS) during the period of aortic clamping. Additionally, normal saline was used in both groups to reach a target pulmonary artery occlusion pressure of 15-18 mmHg. pH, Paco2, and serum concentrations of sodium, potassium, magnesium, calcium, chloride, lactate, albumin, and phosphate were measured. Strong ion difference was calculated as (sodium + potassium + magnesium + calcium) - (chloride + lactate). The amount of weak plasma acid was calculated. The infusion of HSD resulted in an immediate large increase in serum sodium (19 mmol/L) and chloride (22 mmol/L), whereas the infusion of H-NS led only to mild increases in serum sodium (3 mmol/L) and chloride (6 mmol/L). Both HSD and H-NS caused concomitant and equal decreases in the amount of weak plasma acid, strong ion difference, and pH (7.28-7.30). The reduction of bicarbonate was also identical and proportional to the extent of dilution due to infusion of HSD and H-NS. This induced metabolic acidosis was corrected spontaneously in both groups 24 hrs after surgery. Both the intravenous administration of 7.5% sodium chloride and the conventional fluid regimen with saline-based 6% hydroxyethyl starch solution resulted in a metabolic acidosis of equal extent. This suggests dilution of plasma buffers or a decrease in strong ion difference to be the primary cause of metabolic acidosis.

Effect of Bicarbonated Ringer's Solution on the Acid-base Balance in Patients Undergoing Abdominal Aortic Aneurysm Repair

The present study was designed to assess whether prophylactic use of bicarbonated Ringer's solution ameliorates metabolic acidosis in patients undergoing aortic surgery. Twenty patients undergoing elective infrarenal aortic aneurysm repair were randomly assigned to receive either bicarbonated Ringer's solution or acetated Ringer's solution. The pH, PaCO(2), and base excess (BE) were measured before surgical incision (T0), 5 min before reperfusion (T1), 5 min after reperfusion (T2), and 30 min after reperfusion (T3). Data were compared between the two groups. Both pH and BE initially showed a slight decrease in both groups during clamping. After unclamping of the aorta, an additional decrease in pH was observed in both groups (T0 to T2, and T3). There were no significant differences in pH between the groups throughout the study period. Aortic cross-clamping leads to the development of metabolic acidosis, with a decrease in pH and BE. The effect of administration of bicarbonated infusion fluid during elective abdominal aortic surgery had not significant compared with that of acetated Ringer's solution with respect to acid-base homeostasis.

Acid-base homeostasis with the high convective dialysis treatments.

The feedback between metabolic acid production and dialytic base gain ensures a neutral acid-base balance in patients on renal replacement therapy (RRT). Despite acid not accumulating continuously, clinical studies demonstrated that normalizing pre-dialysis serum bicarbonate results in nutritional and osteodystrophy improvements. Full correction of acidosis is not an easy task in dialysis patients because it depends on both some intrinsic characteristics of patients and dialysis prescriptions. Thus, a large variation in the result is often recorded among dialysis populations and in acid-base studies. Highly convective dialysis treatments make the individualization of dialytic parameters easier than conventional dialysis. Up to now, few clinical data have been published. However, knowledge of and the quantification of the kinetic phenomena that govern the buffer transfer during a session of these high performance treatments can provide a rational approach to the optimal dialysis prescription.