Does postprandial lipemia interfere with blood gas analysis and assessment of acid-base status in dogs?

To evaluate the interference of postprandial lipemia on blood gas parameters and to assess the acid-base status by the quantitative approach of the strong ion model blood samples of 15 healthy dogs were collected during fasting (0 h) and at one (1 h), three (3 h) and five (5 h) hours after the induction of lipemia with a hypercaloric diet. Total cholesterol (TC) and triglyceride (TG) levels were used to assess lipemia and these were correlated with the parameters evaluated accordingly. Anion gap decreased at 5 h without correlation with TC and TG, whereas other parameters measured by the blood gasometer did not change. In the evaluation of the acid base state, the apparent strong ion difference (SIDa) and the strong ion gap (SIG) showed a decrease at 5 h without correlation with lipemia. Lipid levels correlated with the effective strong ion difference (SIDe), the concentration of total non-volatile weak acids (Atot), albumin, phosphate, and magnesium. The SIDe increased at 1 h and at 3 h; the Atot at 1 h, 3 h, and 5 h; albumin increased at 1 h and 3 h; phosphate increased at 1 h, 3 h and 5 h; and magnesium decreased at 5 h. Though postprandial lipemia does not interfere with blood gas analysis, it can cause errors in the variables used to assess the acid-base status, which are dependent on biochemical analytes. Therefore, caution is required when interpreting electrolyte disturbances that result from the postprandial state.

Role of electrolyte abnormalities and unmeasured anions in the metabolic acid-base abnormalities in dogs with parvoviral enteritis.

BACKGROUND: The strong ion model (SIM) is an alternative paradigm in the characterization of acid-base disturbances particularly in complex disorders. HYPOTHESIS/OBJECTIVES: To compare the acid-base changes in dogs with parvoviral enteritis (PE) using the Henderson-Hasselbalch (HH) approach, with 2 strong ion approaches. ANIMALS: Forty-four dogs with PE, and 16 age-matched control dogs. METHODS: Prospective controlled observational study. Acid-base status was evaluated using the HH model, Fencl-Stewart (FS) approach and a validated strong ion model (VDM). The acid-base changes according to each model were classified and compared. Statistical correlations between pH, CO2 , and various SIM variables were performed, as well as between the sum of effects (SOE) of the SIM and the individual variables comprising the SOE. RESULTS: The HH model identified acid-base disorders in 31/44 cases of which 16/31 were mixed with metabolic acidosis and concurrent respiratory alkalosis the most common (10/31). Using the FS approach, metabolic changes were present 36/42 cases, with changes in free water (FW), chloride, and unmeasured anions (UA) being the most prevalent. Both FW and UA correlated well with pH; however, UA were most consistently abnormal in severe acidemia. Similarly to the HH, the VDM detected acid-base disturbances in 28/44 cases. Major contributors to the acid-base changes were hyponatremia, hypochloremia, and Atot acidosis because of elevated globulins and increased UA. CONCLUSIONS AND CLINICAL IMPORTANCE: Acid-base changes are common and complex in dogs with PE, and were easier to understand using a SIM paradigm. Increases in UA have not been documented in PE in dogs.

Identifying hydric, electrolytic and acid-base imbalances through traditional and quantitative approaches in dogs with hemorrhagic gastroenteritis / Identificação de desequilíbrios hídricos, eletrolíticos e ácido-base pelas abordagens tradicional e quantitativa em cães com gastroenterite hemorrágica

Vomiting and diarrhea are two important clinical signs that can cause significant electrolytic and acid-base imbalances. The purposes of this study were to characterize hydric, electrolytic and acid-base disorders presented by puppies with hemorrhagic gastroenteritis and to compare the traditional and quantitative approaches to acid-base status interpretation. Sixty-one animals with a history of vomiting and/or diarrhea were used in this study and the following tests were performed: complete blood count, total plasma protein concentration and hemogasometry. Mean, standard deviation and Kappa values were calculated. The imbalances characterized by both approaches were: 42 (69%) animals without imbalance, 17 (28%) with metabolic alkalosis and 2 (3%) with metabolic acidosis by the traditional approach and 17 (28%) dogs without imbalance, 26 (43%) with metabolic alkalosis and 18 (29%) with metabolic acidosis by the quantitative approach. The agreement calculated between two approaches coincide in 28 cases, with a moderate Kappa value equivalent to 0.459. The most found imbalances were metabolic alkalosis, hypokalemia, and mild dehydration. Most of acid-base disturbances were not identified by the traditional approach, whereas by the quantitative approach, they were easily determined. Thus quantitative approach proved to be superior in identification of possible acid-base imbalances.(AU)

Vômito e diarreia são dois sinais clínicos importantes, que podem causar desequilíbrios eletrolíticos e ácido-base importantes. Os objetivos deste trabalho foram caracterizar os desequilíbrios hídrico, eletrolítico e ácido-base apresentados por filhotes de cães com gastroenterite hemorrágica e comparar as abordagens de interpretação do equilíbrio ácido-base tradicional e quantitativa. Sessenta e um animais com histórico de vômito e/ou diarreia foram utilizados neste estudo, e os seguintes testes foram realizados: hemograma, concentração de proteína total plasmática e hemogasometria. Média, desvio-padrão e valor de Kappa foram calculados. Os desequilíbrios caracterizados pelas duas abordagens foram: 42 (69%) animais sem desequilíbrio, 17 (28%) com alcalose metabólica e dois (3%) com acidose metabólica, pela abordagem tradicional, e 17 (28%) cães sem desequilíbrio, 26 (43%) com alcalose metabólica e 18 (29%) com acidose metabólica, pela abordagem quantitativa. A concordância calculada entre as duas abordagens coincidiu em 28 casos, com um valor de Kappa moderado, equivalente a 0,459. Os desequilíbrios mais encontrados foram alcalose metabólica, hipocalemia e desidratação leve. A maioria dos distúrbios não foram identificados pela abordagem tradicional, enquanto, pela abordagem quantitativa, foram facilmente determinados. Portanto, a abordagem quantitativa provou-se superior na identificação de possíveis desequilíbrios ácido-base.(AU)

Age-dependent physiological dynamics in acid-base balance, electrolytes, and blood metabolites in growing goats.

There is a paucity of published data reporting acid-base equilibrium in goats, and no information is available on how the acid-base complexity changes when suckling goat kids become ruminants. The aims of this study were to evaluate young healthy goats for age-related changes in serum proteins, metabolites, and electrolytes; differences in results when the Henderson-Hasselbalch equation or strong ion approaches were used were also assessed. To assess biological variability and reproducibility, two consecutive long-term studies, each lasting from the 6th to 56th week of life (wl), were performed in 15 (Study 1) and 10 (Study 2) animals. Blood gas analysis, serum biochemical analysis, and electrophoresis were performed on venous blood, and acid-base information was obtained using the traditional Henderson-Hasselbalch approach, Stewart's strong ion model, and Constable's simplified strong ion model. In all goats within the first 4-5 months, serum concentrations of glucose, l-lactate, and inorganic phosphate decreased significantly, while serum concentrations of total protein, albumin, and gamma globulin increased. Consequently, nonvolatile weak acids (Atot Alb and Atot TP) increased. At the end of this 'adaptation period', i.e. when milk was replaced by purely plant-based food, significantly lower bicarbonate and base excess values were accompanied by blood pH that shifted towards acidosis. Electrolytes (Na+, K+, Ca2+, and Cl-), anion gap, strong ion difference, and strong ion gap did not show age-dependent trends. In conclusion, somatic growth and development of gastro-intestinal fermentation in growing goats act as complex sources of physiological variability on acid-base equilibrium that was not reflected by the Henderson-Hasselbalch equation only.

The central role of chloride in the metabolic acid-base changes in canine parvoviral enteritis.

The acid-base disturbances in canine parvoviral (CPV) enteritis are not well described. In addition, the mechanisms causing these perturbations have not been fully elucidated. The purpose of the present study was to assess acid-base changes in puppies suffering from CPV enteritis, using a modified strong ion model (SIM). The hypothesis of the study was that severe acid-base disturbances would be present and that the SIM would provide insights into pathological mechanisms, which have not been fully appreciated by the Henderson-Hasselbalch model. The study analysed retrospective data, obtained from 42 puppies with confirmed CPV enteritis and 10 healthy control dogs. The CPV-enteritis group had been allocated a clinical score, to allow classification of the data according to clinical severity. The effects of changes in free water, chloride, l-lactate, albumin and phosphate were calculated, using a modification of the base excess algorithm. When the data were summated for each patient, and correlated to each individual component, the most important contributor to the metabolic acid-base changes, according to the SIM, was chloride (P<0.001). Severely-affected animals tended to demonstrate hypochloraemic alkalosis, whereas mildly-affected puppies had a hyperchloraemic acidosis (P=0.007). In conclusion, the acid-base disturbances in CPV enteritis are multifactorial and complex, with the SIM providing information in terms of the origin of these changes.