Ânions não mensuráveis são responsáveis pela maior parte da acidose metabólica de pacientes com hiperlactatemia

PURPOSE: To characterize the different components of metabolic acidosis in patients with hyperlactatemia in order to determine the degree to which lactate is responsible for the acidosis and the relevance that this might have in the outcome of these patients. METHODS: Arterial blood gas, arterial lactate, Na+, K+, Ca2+, Mg2+, Cl-, phosphate, albumin, and creatinine were measured on admission to make a diagnosis of the acid-base disturbances present. Intensive Care Unit and in-hospital mortality were also recorded. RESULTS: A total of 58 patients with hyperlactatemia were included. They usually had a mild acidemia (pH 7.31 &plusmn; 0.12) and a significantly high Standard Base Deficit (7.6 &plusmn; 6.7 mEq/L). In addition to lactate (4.3 &plusmn; 2.3 mEq/L), chloride (106.9 &plusmn; 9.5 mEq/L) and unmeasured anions (8.6 &plusmn; 5.0 mEq/L) accounted for the metabolic acidosis. Unmeasured anions were primarily responsible for the acidosis in both Intensive Care Unit survivors and nonsurvivors (44.7% &plusmn; 26.0% and 46.0% &plusmn; 17.5%, respectively, P = 0.871). Lactate contributed in similar percentages to the acidosis in both groups (23.0% &plusmn; 11.8% and 24.2% &plusmn; 9.7% in Intensive Care Unit survivors and nonsurvivors, respectively; P = 0.753). Correlation between Standard Base Deficit and lactate was found only in Intensive Care Unit nonsurvivors (r = 0.662, P < 0.01). DISCUSSION: Hyperlactatemia is usually accompanied by metabolic acidemia, but lactate is responsible for a minor percentage of the acidosis; unmeasured anions account for most of the acidosis in patients with hyperlactatemia. The percentage of the acidosis due to hyperlactatemia was not relevant in terms of outcome.OBJETIVO: Caracterizar os diferentes componentes da acidose metabólica de pacientes com hiperlactatemia de modo a verificar o quanto o lactato é responsável pela acidose e a relevância que isso possa ter no prognóstico desses pacientes. MÉTODOS: Gasometria arterial com dosagem de lactato, Na+, K+, Ca2+, Mg2+, Cl-, fosfato, albumina e creatinina séricas foram coletados no momento da admissão para fazer o diagnóstico dos possíveis distúrbios ácido-básicos presentes. Mortalidade na UTI e mortalidade hospitalar foram avaliadas. RESULTADOS: Um total de 58 pacientes com hiperlactatemia foram incluídos. Eles tinham na média uma acidemia leve (pH 7.31 &plusmn; 0.12) e o déficit de base significativamente elevado (7.6 &plusmn; 6.7 mEq/L). Além do lactato (4.3 &plusmn; 2.3 mEq/L), o cloro (106.9 &plusmn; 9.5 mEq/L) e os ânions não mensuráveis (8.6 &plusmn; 5.0 mEq/L) contribuíram para a acidose metabólica. Os ânions não mensuráveis foram responsáveis pela maior parcela da acidose tanto nos pacientes que tiveram alta da UTI como nos que faleceram (44.7 &plusmn; 26.0 % e 46.0 &plusmn; 17.5 %, respectivamente, p= 0.871). O lactato contribuiu em percentagens semelhantes para a acidose em ambos os grupos (23.0 &plusmn; 11.8 % nos sobreviventes e 24.2 &plusmn; 9.7 % nos óbitos, p= 0.753). Correlação entre o déficit de base e o lactato somente foi encontrada nos óbitos (r = 0.662, p < 0.01). DISCUSSÃO: Hiperlactatemia é comumente acompanhada de acidemia metabólica, porém o lactato corresponde a uma parcela minoritária da acidose; ânions não mensuráveis contribuem com a maior parte da carga ácida em pacientes hiperlactatêmicos. O percentual da acidose devido à hiperlactatemia não foi relevante em termos de prognóstico

Case Report Urine Biochemistry in the Early Postoperative Period after Cardiac Surgery: Role in Acute Kidney Injury Monitoring

We have recently suggested that sequential urine electrolyte measurement in critically ill patients may be useful in monitoring kidney function. Cardiac surgery is one of the leading causes of acute kidney injury (AKI) in the intensive care unit (ICU). In this paper, we describe the sequential behavior of urine electrolytes in three patients in the early (first 60 hours) postoperative period after cardiac surgery according to AKI status: no AKI, transient AKI, and persistent AKI. We have found that the patient with no AKI had stable and high concentrations of sodium (NaU) and chloride (ClU) in sequential spot samples of urine. AKI development was characterized in the other two patients by decreases in NaU and ClU, which have started early after ICU admission. Transient AKI was marked by also transient and less severe decreases in NaU and ClU. Persistent AKI was marked by the less favorable clinical course with abrupt and prolonged declines in NaU and ClU values. These electrolytes in urine had a behavior like a &quot;mirror image&quot; in comparison with that of serum creatinine. We suggest that sequential urine electrolytes are useful in monitoring acute kidney injury development in the early postoperative period after cardiac surgery

Characterization of an animal model of severe sepsis associated with respiratory dysfunction

PURPOSE: Pathophysiological studies in humans regarding sepsis are difficult to perform due to ethical and methodological concerns. In this context, animal models of sepsis can be useful to better understand this condition and to test therapeutic strategies. The purpose of this study was to characterize a feasible and clinically relevant model of sepsis in pigs that could be useful for testing different therapeutic interventions. METHODS: 5 White Large pigs were anesthetized, arterial and pulmonary catheters were introduced, and sepsis was induced by fecal peritonitis. Several biochemical indicators of organ dysfunction and infectious parameters were measured. The pigs were monitored until death, when fragments of organs were removed for pathology. Three animals without peritonitis served as controls and were sacrificed 24 hours after surgery without developing significant changes in organ function. RESULTS: Septic pigs survived 17 hours on average (range, 16-18 h), and Escherichia coli was recovered from blood cultures. They developed a significant decrease in left ventricular work and a nonsignificant reduction in mixed venous oxygen saturation. Respiratory dysfunction was characterized by a decrease in the PaO2/FiO2 ratio and respiratory compliance. Pathology of the lungs revealed areas of pulmonary collapse, hemorrhage, pulmonary congestion, and discrete neutrophil infiltrate. CONCLUSIONS: Fecal peritonitis in pigs is a clinically relevant model of sepsis associated with acute lung injury without direct pulmonary insult. This model may prove to be useful for studying pathogenic aspects of secondary lung injury as well as for validating ventilatory or pharmacologic interventions.PROPOSTA: Estudos sobre sepse envolvendo sua fisiopatologia são difíceis de serem realizados devido a razões éticas e metodológicas. Neste sentido, modelos animais criam oportunidades de estudos para entender a fisiopatologia e testar estratégias terapêuticas. O objetivo deste estudo foi criar um modelo relevante de choque séptico em porcos para testar e entender diferentes intervenções. MÉTODOS: 5 porcos da raça "White Large" foram anestesiados e monitorizados com uma linha arterial e um cateter de artéria pulmonar. Uma peritonite fecal foi induzida através de laparotomia. Marcadores de disfunções orgânicas e infecciosos foram mensurados. Todos porcos evoluíram até a morte e amostras de órgãos foram coletadas para exame anátomo patológico. Três animais controles com o mesmo preparo cirúrgico e sem peritonite foram sacrificados após 24 horas de evolução, sem desenvolver mudanças significativas nas funções orgânicas. RESULTADOS: Os animais séptico sobreviveram na média 17 horas (16 - 18h), e Escherichia coli foi cultivada nas amostras de sangue. Os animais sépticos evoluíram com redução do trabalho de ventrículo esquerdo. A disfunção respiratória foi caracterizada por uma redução na relação PaO2/FiO2 e na complacência respiratória. A anatomia patológica dos pulmões revelou colapso pulmonar, hemorragia, congestão e infiltrado neutrofílico. CONCLUSÕES: A peritonite fecal em porcos é um modelo de choque séptico clinicamente relevante e associada a uma lesão pulmonar sem um insulto direto. Este é um modelo que pode ser utilizado para estudar aspectos fisiopatológicos das lesões pulmonares secundárias, assim como para estudar intervenções ventilatórias ou farmacológicas

Standard base excess e o nível sérico de lactato evolutivos nos pacientes com sepse grave e choque séptico reanimados com o early goal directed therapy: ainda discriminadores de mortalidade?

PURPOSE: To compare the evolution of standard base excess and serum lactate level between surviving and non surviving patients with severe sepsis and septic shock resuscitated with early goal-directed therapy. METHODS: This is a retrospective study in an intensive care unit of a university tertiary hospital where 65 consecutive severe sepsis and septic shock patients were observed without any intervention in the treatment by the authors of this report. RESULTS: In our study, the mortality of severe sepsis and septic shock patients was 38%. The central venous oxygen saturation of both groups was above 70% after the resuscitative period, excluding the second day of the non survivors group (69.8%). After the second day, the central venous oxygen saturation was significantly higher in the survivors group (P < .001). Standard base excess was initially low in both groups, but from the second day on, the correction of standard base excess was significantly more successful and linear in the survivor group (P < .001). Lactate levels were similar during the evolution of both groups. CONCLUSIONS: Although evolutive standard base excess and serum lactate level are still outcome markers in severe sepsis and septic shock patients resuscitated with early goal-directed therapy, other studies must be performed to clarify if hemodynamic interventions based on standard base excess and serum lactate level could be reliable to improve clinical outcomes in severe sepsis and septic shock patients.OBJETIVO: Comparar a evolução do "standard base excess" e o nível de lactato sérico entre pacientes sobreviventes e não sobreviventes com sepse grave ou choque séptico reanimados com o "early goal directed therapy". MÉTODOS: Estudo retrospectivo em uma unidade de terapia intensiva de um hospital escola onde sessenta e cinco pacientes com sepse grave e choque séptico foram observados sem intervenções. RESULTADOS: Em nosso estudo, a mortalidade na sepse grave e choque séptico foi de 38%. A saturação venosa central de oxigênio nos dois grupos foi maior que 70% depois da reanimação, exceto no segundo dia no grupo dos pacientes não sobreviventes (69,8%). Depois do segundo dia, a saturação venosa central foi significantemente maior no grupo dos sobreviventes (

Hemodynamic and respiratory support using venoarterial extracorporeal membrane oxygenation (ECMO) in a polytrauma patient

Existem poucos relatos na literatura sobre o uso de oxigenação extracorpórea por membrana venoarterial por dupla disfunção decorrente de contusão cardíaca e pulmonar no paciente politraumatizado. Relatamos o caso de um paciente de 48 anos, vítima de acidente de motocicleta e automóvel, que evoluiu rapidamente com choque refratário com baixo débito cardíaco por contusão miocárdica e hipoxemia refratária decorrente de contusão pulmonar, tórax instável e pneumotórax bilateral. O suporte extracorpóreo foi uma medida efetiva de resgate para esse caso dramático, e o seu uso pôde ser interrompido com sucesso no 4º dia após o trauma. O paciente evoluiu com extenso infarto cerebral, morrendo no 7º dia de internaçãoThere are few reports in the literature regarding the use of venoarterial extracorporeal membrane oxygenation (ECMO) for double-dysfunction from both heart and lung contusions in polytrauma patients. This article reports a 48-year-old patient admitted after a traffic accident. He rapidly progressed to shock with low cardiac output due to myocardial contusion and refractory hypoxemia due to pulmonary contusion, an unstable chest wall and bilateral pneumothorax. ECMO was an effective rescue procedure in this dramatic situation and was successfully discontinued on the fourth day after the trauma. The patient also developed an extensive brain infarction and eventually died on the seventh day after admissio

Severe hypoxemia during veno-venous extracorporeal membrane oxygenation: exploring the limits of extracorporeal respiratory support

OBJECTIVE: Veno-venous extracorporeal oxygenation for respiratory support has emerged as a rescue alternative for patients with hypoxemia. However, in some patients with more severe lung injury, extracorporeal support fails to restore arterial oxygenation. Based on four clinical vignettes, the aims of this article were to describe the pathophysiology of this concerning problem and to discuss possibilities for hypoxemia resolution. METHODS: Considering the main reasons and rationale for hypoxemia during veno-venous extracorporeal membrane oxygenation, some possible bedside solutions must be considered: 1) optimization of extracorporeal membrane oxygenation blood flow; 2) identification of recirculation and cannula repositioning if necessary; 3) optimization of residual lung function and consideration of blood transfusion; 4) diagnosis of oxygenator dysfunction and consideration of its replacement; and finally 5) optimization of the ratio of extracorporeal membrane oxygenation blood flow to cardiac output, based on the reduction of cardiac output. CONCLUSION: Therefore, based on the pathophysiology of hypoxemia during veno-venous extracorporeal oxygenation support, we propose a stepwise approach to help guide specific interventions