RESUMO

SUMMARY OBJECTIVE: The aim of this study was to evaluate the accuracy of intrapartum cardiotocography in identifying acidemia at birth by umbilical cord blood gasometry in high-risk pregnancies. METHODS: This was a retrospective cohort study of singleton high-risk parturients using intrapartum cardiotocography categories I, II, and III. The presence of fetal acidemia at birth was identified by the analysis of umbilical cord arterial blood pH (<7.1). Associations between variables were determined using the chi-square test and Kruskal-Wallis tests. RESULTS: We included 105 cases of cardiotocography category I, 20 cases of cardiotocography category II, and 10 cases of cardiotocography category III. cardiotocography category III had a higher prevalence of cesarean sections compared to cardiotocography category I (90.0 vs. 42.9%, p<0.006). Venous pH was higher in patients with cardiotocography category I compared to cardiotocography category III (7.32 vs. 7.23, p=0.036). Prevalence of neonatal intensive care unit (NICU) admission was lower in neonates of patients with cardiotocography category I compared to cardiotocography category III (3.8 vs. 30.0%, p=0.014). Prevalence of composite adverse outcomes was lower in neonates of patients with cardiotocography category I compared to cardiotocography category II (9.5 vs. 30.0%, p=0.022) and cardiotocography category III (9.5 vs. 60.0%, p=0.0004). cardiotocography categories II and III had low sensitivity (0.05 and 0.00, respectively) and high negative predictive value (NPV) (0.84 and 0.91, respectively) for identifying fetal acidemia at birth. The three categories of intrapartum cardiotocography showed high specificities (96.0, 99.0, and 99.0%, respectively). CONCLUSION: All three categories of intrapartum cardiotocography showed low sensitivity and high specificity for identifying acidemia at birth.

RESUMO

SUMMARY OBJECTIVE: The aim of this study was to evaluate the accuracy of intrapartum cardiotocography in identifying fetal acidemia by umbilical cord blood analysis in low-risk pregnancies. METHODS: This is a retrospective cohort study of low-risk singleton pregnancies in labor after performing intrapartum cardiotocography categories I, II, and III. The presence of fetal acidemia at birth was identified by analyzing the pH of umbilical cord arterial blood (pH<7.1). RESULTS: No significant effect of the cardiotocography category on the arterial (p=0.543) and venous (p=0.770) pH of umbilical cord blood was observed. No significant association was observed between the cardiotocography category and the presence of fetal acidemia (p=0.706), 1-min Apgar score <7 (p=0.260), hospitalization in the neonatal intensive care unit (p=0.605), newborn death within the first 48 h, need for neonatal resuscitation (p=0.637), and adverse perinatal outcomes (p=0.373). Sensitivities of 62, 31, and 6.0%; positive predictive values of 11.0, 16.0, and 10.0%; and negative predictive values of 85, 89.0, and 87.0% were observed for cardiotocography categories I, II, and III, respectively. CONCLUSION: The three categories of intrapartum cardiotocography presented low sensitivities and high negative predictive values to identify fetal acidemia at birth in low-risk pregnancies.

RESUMO

In the epidemiological COVID-19 research, artificial intelligence is a unique approach to make predictions about disease severity to manage COVID-19 patients. A limitation of artificial intelligence is, however, the high risk of bias. We investigated the skill of data mining and machine learning, two advanced forms of artificial intelligence, to predict severe COVID-19 pneumonia based on routine laboratory tests. A sample of 4009 COVID-19 patients was divided into Severe (PaO2< 60 mmHg, 489 cases) and Non-Severe (PaO2 ≥ 60 mmHg, 3520 cases) groups according to blood hypoxemia on admission and their laboratory datasets analyzed by the R software and WEKA workbench. After curation, data were processed for the selection of the most influential features including hemogram, pCO2, blood acid-base balance, prothrombin time, inflammation biomarkers, and glucose. The best fit of variables was successfully confirmed by either the Multilayer Perceptron, a feedforward neural network algorithm that performed machine recognition of severe COVID-19 with 96.5% precision, or by the C4.5 software, a supervised learning algorithm based on an objective-predefined variable (severity) that generated a decision tree with 89.4% precision. Finally, a complex bivariate Pearson's correlation matrix combined with advanced hierarchical clustering (dendrograms) were conducted for knowledge discovery. The hidden structure of the datasets revealed shift patterns related to the development of COVID-19-induced pneumonia that involved the lymphocyte-to-C-reactive protein and leukocyte-to-C-protein ratios, neutrophil %, pH and pCO2. The data mining approaches to the hematological fluctuations associated with severe COVID-19 pneumonia could not only anticipate adverse clinical outcomes, but also reveal putative therapeutic targets.

Assuntos

RESUMO

Abstract Background: Cardiac surgery can produce persistent deficit in the ratio of Oxygen Delivery (DO2) to Oxygen Consumption (VO2). Central venous oxygen Saturation (ScvO2) is an accessible and indirect measure of DO2/VO2 ratio. Objective: To monitor perioperative ScvO2 and assess its correlation with mortality during cardiac surgery. Methods: This prospective observational study evaluated 273 patients undergoing cardiac surgery. Blood gas samples were collected to measure ScvO2 at three time points: T0 (after anesthetic induction), T1 (end of surgery), and T2 (24 hours after surgery). The patients were divided into two groups (survivors and nonsurvivors). The following outcomes were analyzed: intrahospital mortality, length of Intensive Care Unit (ICU) and hospital stay (LOS), and variation in ScvO2. Results: Of the 273 patients, 251 (92%) survived and 22 (8%) did not. There was a significant perioperative reduction of ScvO2 in both survivors (T0 = 78% ± 8.1%, T1 = 75.4% ± 7.5%, and T2 = 68.5% ± 9%; p< 0.001) and nonsurvivors (T0 = 74.4% ± 8.7%, T1 = 75.4% ± 7.7%, and T2 = 66.7% ± 13.1%; p < 0.001). At T0, the percentage of patients with ScvO2< 70% was greater in the nonsurvivor group (31.8% vs. 13.1%; p= 0.046) and the multiple logistic regression showed that ScvO2 is an independent risk factor associated with death, OR = 2.94 (95% CI 1.10−7.89) (p= 0.032). The length of ICU and LOS were 3.6 ± 3.1 and 7.4 ± 6.0 days respectively and was not significantly associated with ScvO2. Conclusions: Early intraoperative ScvO2 < 70% indicated a higher risk of death. A perioperative reduction of ScvO2 was observed in patients undergoing cardiac surgery, with high intraoperative and lower postoperative levels.

Resumo Justificativa: A cirurgia cardíaca pode produzir déficit persistente na razão entre oferta de oxigênio (DO2) e consumo de oxigênio (VO2). A Saturação venosa central de Oxigênio (SvcO2) é uma medida acessível e indireta da razão DO2/VO2. Objetivo: Monitorar a SvcO2 perioperatória e avaliar sua correlação com a mortalidade em cirurgia cardíaca. Método: Este estudo observacional prospectivo avaliou 273 pacientes submetidos a cirurgia cardíaca. Coletamos amostras de sangue para medir a SvcO2 em três momentos: T0 (após indução anestésica), T1 (final da cirurgia) e T2 (24 horas após a cirurgia). Os pacientes foram divididos em dois grupos (sobreviventes e não sobreviventes). Os seguintes desfechos foram analisados: mortalidade intra-hospitalar, tempo de permanência na Unidade de Terapia Intensiva (UTI) e de internação hospitalar, e variação na SvcO2. Resultados: Dos 273 pacientes, 251 (92%) sobreviveram e 22 (8%) não. Houve queda significante da SvcO2 perioperatória nos sobreviventes (T0 = 78% ± 8,1%, T1 = 75,4% ± 7,5% e T2 = 68,5% ± 9%; p< 0,001) e nos não sobreviventes (T0 = 74,4% ± 8,7%, T1 = 75,4% ± 7,7% e T2 = 66,7% ± 13,1%; p< 0,001). No T0, a porcentagem de pacientes com SvcO2< 70% foi maior no grupo não sobrevivente (31,8% vs. 13,1%; p = 0,046) e a regressão logística múltipla mostrou que a SvcO2 é um fator de risco independente associado ao óbito, OR = 2,94 (95% IC 1,10 − 7,89) (p = 0,032). O tempo de permanência na UTI e de hospitalização foi de 3,6 ± 3,1 e 7,4 ± 6,0 dias, respectivamente, e não foi significantemente associado à SvcO2. Conclusões: Valores precoces de SvcO2 intraoperatória < 70% indicaram maior risco de óbito em pacientes submetidos à cirurgia cardíaca. Observamos redução perioperatória da SvcO2, com altos níveis no intraoperatório e mais baixos no pós-operatório.

Assuntos

RESUMO

BACKGROUND: Cardiac surgery can produce persistent deficit in the ratio of Oxygen Delivery (DO2) to Oxygen Consumption (VO2). Central venous oxygen Saturation (ScvO2) is an accessible and indirect measure of DO2/VO2 ratio. OBJECTIVE: To monitor perioperative ScvO2 and assess its correlation with mortality during cardiac surgery. METHODS: This prospective observational study evaluated 273 patients undergoing cardiac surgery. Blood gas samples were collected to measure ScvO2 at three time points: T0 (after anesthetic induction), T1 (end of surgery), and T2 (24hours after surgery). The patients were divided into two groups (survivors and nonsurvivors). The following outcomes were analyzed: intrahospital mortality, length of Intensive Care Unit (ICU) and hospital stay (LOS), and variation in ScvO2. RESULTS: Of the 273 patients, 251 (92%) survived and 22 (8%) did not. There was a significant perioperative reduction of ScvO2 in both survivors (T0=78%± 8.1%, T1=75.4%±7.5%, and T2=68.5%±9%; p<0.001) and nonsurvivors (T0=74.4%±8.7%, T1=75.4%±7.7%, and T2=66.7%±13.1%; p <0.001). At T0, the percentage of patients with ScvO2 <70% was greater in the nonsurvivor group (31.8% vs. 13.1%; p=0.046) and the multiple logistic regression showed that ScvO2 is an independent risk factor associated with death, OR=2.94 (95% CI 1.10-7.89) (p=0.032). The length of ICU and LOS were 3.6±3.1 and 7.4±6.0 days respectively and was not significantly associated with ScvO2. CONCLUSIONS: Early intraoperative ScvO2 <70% indicated a higher risk of death. A perioperative reduction of ScvO2 was observed in patients undergoing cardiac surgery, with high intraoperative and lower postoperative levels.

Assuntos

RESUMO

The effects of a new intravenous polyionic solution on electrolyte and acid-base balances in cattle were evaluated. Eight healthy adult, crossbred Bos taurus cattle received two treatments in a cross-over design: isotonic saline solution (IS) and test solution (TS) with 145 mEq of Na+, 5 mEq of K+, 4 mEq of Ca++, 2 mEq of Mg++, 96 mEq of Cl-, 60 mEq of lactate, 50 g of dextrose, and 4 mg of cyanocobalamin per liter. The solutions were IV infused in a volume corresponding to 5% of BW, through 3 hours. Venous blood samples were taken before the infusion and 3, 6, 9, and 24 hours after the beginning of the infusion. Glucose, L-lactate, Ca, P, Mg, pH, pCO2, HCO3-, BE, Na+, K+, Cl-, and Ca++ were measured. Data were analyzed through repeated measures ANOVA. IS caused acidifying effect due to hyperchloremia and decreased plasma strong ion difference (SID). On the contrary, TS induced mild and transient alkalinization without changes in Na+ and Cl- plasma levels. Transient hypokalemia and hyperglycemia were presented at the end of the ST infusion but did not provoke apparent clinical signs. We concluded that TS is a safe choice for fluid therapy in cattle, inducing low magnitude iatrogenic changes as an advantage.(AU)

Objetivou-se avaliar os efeitos de uma nova solução hidratante intravenosa sobre os equilíbrios eletrolítico e ácido-base de bovinos. Para tanto, oito animais adultos hígidos, mestiços taurinos foram submetidos a dois tratamentos em delineamento cross-over: solução salina isotônica (SI) e solução teste (ST) composta por 145 mEq de Na+, 5 mEq de K+, 4 mEq de Ca++, 2 mEq de Mg++, 96 mEq de Cl-, 60 mEq de lactato, 50 g de dextrose e 4 mg de cianocobalamina por litro. As soluções foram administradas por via intravenosa, em volume correspondente a 5% do peso corporal, durante três horas de infusão contínua. Amostras de sangue venoso foram colhidas antes da infusão e três, seis, nove e 24 horas após o início da infusão para determinações de glicose, lactato L, Ca, P, Mg, pH, pCO2, HCO3-, BE, Na+, K+, Cl- e Ca++. Os resultados foram analisados por análise de variâncias de medidas repetidas. Ao contrário da SI, que causou hipercloremia e redução da diferença de íons fortes no plasma (SID), determinando efeito acidificante, a ST gerou alcalinização leve e transitória e não provocou alteração das concentrações de Na+ e de Cl-. A hipopotassemia e a hiperglicemia, presentes ao final da infusão da ST, foram transitórias e não determinaram sinais clínicos evidentes. Conclui-se que a ST é uma alternativa segura para a terapia com fluidos em bovinos, tendo a vantagem de provocar alterações iatrogênicas de baixa magnitude.(AU)

Assuntos

RESUMO

The effects of a new intravenous polyionic solution on electrolyte and acid-base balances in cattle were evaluated. Eight healthy adult, crossbred Bos taurus cattle received two treatments in a cross-over design: isotonic saline solution (IS) and test solution (TS) with 145 mEq of Na+, 5 mEq of K+, 4 mEq of Ca++, 2 mEq of Mg++, 96 mEq of Cl-, 60 mEq of lactate, 50 g of dextrose, and 4 mg of cyanocobalamin per liter. The solutions were IV infused in a volume corresponding to 5% of BW, through 3 hours. Venous blood samples were taken before the infusion and 3, 6, 9, and 24 hours after the beginning of the infusion. Glucose, L-lactate, Ca, P, Mg, pH, pCO2, HCO3-, BE, Na+, K+, Cl-, and Ca++ were measured. Data were analyzed through repeated measures ANOVA. IS caused acidifying effect due to hyperchloremia and decreased plasma strong ion difference (SID). On the contrary, TS induced mild and transient alkalinization without changes in Na+ and Cl- plasma levels. Transient hypokalemia and hyperglycemia were presented at the end of the ST infusion but did not provoke apparent clinical signs. We concluded that TS is a safe choice for fluid therapy in cattle, inducing low magnitude iatrogenic changes as an advantage.

Objetivou-se avaliar os efeitos de uma nova solução hidratante intravenosa sobre os equilíbrios eletrolítico e ácido-base de bovinos. Para tanto, oito animais adultos hígidos, mestiços taurinos foram submetidos a dois tratamentos em delineamento cross-over: solução salina isotônica (SI) e solução teste (ST) composta por 145 mEq de Na+, 5 mEq de K+, 4 mEq de Ca++, 2 mEq de Mg++, 96 mEq de Cl-, 60 mEq de lactato, 50 g de dextrose e 4 mg de cianocobalamina por litro. As soluções foram administradas por via intravenosa, em volume correspondente a 5% do peso corporal, durante três horas de infusão contínua. Amostras de sangue venoso foram colhidas antes da infusão e três, seis, nove e 24 horas após o início da infusão para determinações de glicose, lactato L, Ca, P, Mg, pH, pCO2, HCO3-, BE, Na+, K+, Cl- e Ca++. Os resultados foram analisados por análise de variâncias de medidas repetidas. Ao contrário da SI, que causou hipercloremia e redução da diferença de íons fortes no plasma (SID), determinando efeito acidificante, a ST gerou alcalinização leve e transitória e não provocou alteração das concentrações de Na+ e de Cl-. A hipopotassemia e a hiperglicemia, presentes ao final da infusão da ST, foram transitórias e não determinaram sinais clínicos evidentes. Conclui-se que a ST é uma alternativa segura para a terapia com fluidos em bovinos, tendo a vantagem de provocar alterações iatrogênicas de baixa magnitude.

Assuntos

RESUMO

Abstract The effects of a new intravenous polyionic solution on electrolyte and acid-base balances in cattle were evaluated. Eight healthy adult, crossbred Bos taurus cattle received two treatments in a cross-over design: isotonic saline solution (IS) and test solution (TS) with 145 mEq of Na+, 5 mEq of K+, 4 mEq of Ca++, 2 mEq of Mg++, 96 mEq of Cl-, 60 mEq of lactate, 50 g of dextrose, and 4 mg of cyanocobalamin per liter. The solutions were IV infused in a volume corresponding to 5% of BW, through 3 hours. Venous blood samples were taken before the infusion and 3, 6, 9, and 24 hours after the beginning of the infusion. Glucose, L-lactate, Ca, P, Mg, pH, pCO2, HCO3-, BE, Na+, K+, Cl-, and Ca++ were measured. Data were analyzed through repeated measures ANOVA. IS caused acidifying effect due to hyperchloremia and decreased plasma strong ion difference (SID). On the contrary, TS induced mild and transient alkalinization without changes in Na+ and Cl- plasma levels. Transient hypokalemia and hyperglycemia were presented at the end of the ST infusion but did not provoke apparent clinical signs. We concluded that TS is a safe choice for fluid therapy in cattle, inducing low magnitude iatrogenic changes as an advantage.

Resumo Objetivou-se avaliar os efeitos de uma nova solução hidratante intravenosa sobre os equilíbrios eletrolítico e ácido-base de bovinos. Para tanto, oito animais adultos hígidos, mestiços taurinos foram submetidos a dois tratamentos em delineamento cross-over: solução salina isotônica (SI) e solução teste (ST) composta por 145 mEq de Na+, 5 mEq de K+, 4 mEq de Ca++, 2 mEq de Mg++, 96 mEq de Cl-, 60 mEq de lactato, 50 g de dextrose e 4 mg de cianocobalamina por litro. As soluções foram administradas por via intravenosa, em volume correspondente a 5% do peso corporal, durante três horas de infusão contínua. Amostras de sangue venoso foram colhidas antes da infusão e três, seis, nove e 24 horas após o início da infusão para determinações de glicose, lactato L, Ca, P, Mg, pH, pCO2, HCO3-, BE, Na+, K+, Cl- e Ca++. Os resultados foram analisados por análise de variâncias de medidas repetidas. Ao contrário da SI, que causou hipercloremia e redução da diferença de íons fortes no plasma (SID), determinando efeito acidificante, a ST gerou alcalinização leve e transitória e não provocou alteração das concentrações de Na+ e de Cl-. A hipopotassemia e a hiperglicemia, presentes ao final da infusão da ST, foram transitórias e não determinaram sinais clínicos evidentes. Conclui-se que a ST é uma alternativa segura para a terapia com fluidos em bovinos, tendo a vantagem de provocar alterações iatrogênicas de baixa magnitude.

RESUMO

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.(AU)

This study aimed to evaluate parameters of acid-base balance in horses submitted to an experimental model of intestinal obstruction. Twenty-four animals were divided in four groups: instrumented control (GI), duodenum obstruction (GII), ileum obstruction (GIII) and large colon obstruction (GIV). Venous blood samples were collected before surgery (T0), during the obstruction (T30ob-T180ob) and after unblocking procedures (T60des-T180des). Animals from GIV, at T30ob and animals from GII, at T60ob, T90ob and T120ob, presented higher values for pH(v), cHCO-3(vP) and cBase(v) which, added to the increase of pCO2(v) and ctCO2(v), characterized the metabolic alkalosis with respiratory compensation. At T90ob and T120ob, in GII animals, and at T180ob, in GIII animals the pO2(v) and sO2(v) had similar response. Low values presented by GII animals were associated to hypercapnia or hypoventilation triggered for metabolic alkalosis correction. However, a hypoxemia presented by GIII animals was associated to hypovolemia at that period. There were light and temporary acid-base alterations that are not capable to predict specific intestinal obstruction diagnosis in equines with colic. However they help in prognosis since both have a direct relation with the precociousness of gastrointestinal disturbance.(AU)

Assuntos

RESUMO

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.

This study aimed to evaluate parameters of acid-base balance in horses submitted to an experimental model of intestinal obstruction. Twenty-four animals were divided in four groups: instrumented control (GI), duodenum obstruction (GII), ileum obstruction (GIII) and large colon obstruction (GIV). Venous blood samples were collected before surgery (T0), during the obstruction (T30ob-T180ob) and after unblocking procedures (T60des-T180des). Animals from GIV, at T30ob and animals from GII, at T60ob, T90ob and T120ob, presented higher values for pH(v), cHCO-3(vP) and cBase(v) which, added to the increase of pCO2(v) and ctCO2(v), characterized the metabolic alkalosis with respiratory compensation. At T90ob and T120ob, in GII animals, and at T180ob, in GIII animals the pO2(v) and sO2(v) had similar response. Low values presented by GII animals were associated to hypercapnia or hypoventilation triggered for metabolic alkalosis correction. However, a hypoxemia presented by GIII animals was associated to hypovolemia at that period. There were light and temporary acid-base alterations that are not capable to predict specific intestinal obstruction diagnosis in equines with colic. However they help in prognosis since both have a direct relation with the precociousness of gastrointestinal disturbance.

RESUMO

This study aimed to evaluate parameters of acid-base balance in horses submitted to an experimental model of intestinal obstruction. Twenty-four animals were divided in four groups: instrumented control (GI), duodenum obstruction (GII), ileum obstruction (GIII) and large colon obstruction (GIV). Venous blood samples were collected before surgery (T0), during the obstruction (T30ob-T180ob) and after unblocking procedures (T60des-T180des). Animals from GIV, at T30ob and animals from GII, at T60ob, T90ob and T120ob, presented higher values for pH(v), cHCO-3(vP) and cBase(v) which, added to the increase of pCO2(v) and ctCO2(v), characterized the metabolic alkalosis with respiratory compensation. At T90ob and T120ob, in GII animals, and at T180ob, in GIII animals the pO2(v) and sO2(v) had similar response. Low values presented by GII animals were associated to hypercapnia or hypoventilation triggered for metabolic alkalosis correction. However, a hypoxemia presented by GIII animals was associated to hypovolemia at that period. There were light and temporary acid-base alterations that are not capable to predict specific intestinal obstruction diagnosis in equines with colic. However they help in prognosis since both have a direct relation with the precociousness of gastrointestinal disturbance.

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.

RESUMO

This study aimed to evaluate parameters of acid-base balance in horses submitted to an experimental model of intestinal obstruction. Twenty-four animals were divided in four groups: instrumented control (GI), duodenum obstruction (GII), ileum obstruction (GIII) and large colon obstruction (GIV). Venous blood samples were collected before surgery (T0), during the obstruction (T30ob-T180ob) and after unblocking procedures (T60des-T180des). Animals from GIV, at T30ob and animals from GII, at T60ob, T90ob and T120ob, presented higher values for pH(v), cHCO-3(vP) and cBase(v) which, added to the increase of pCO2(v) and ctCO2(v), characterized the metabolic alkalosis with respiratory compensation. At T90ob and T120ob, in GII animals, and at T180ob, in GIII animals the pO2(v) and sO2(v) had similar response. Low values presented by GII animals were associated to hypercapnia or hypoventilation triggered for metabolic alkalosis correction. However, a hypoxemia presented by GIII animals was associated to hypovolemia at that period. There were light and temporary acid-base alterations that are not capable to predict specific intestinal obstruction diagnosis in equines with colic. However they help in prognosis since both have a direct relation with the precociousness of gastrointestinal disturbance.

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.