Gastric tonometry versus cardiac index as resuscitation goals in septic shock: A multicenter, randomized, controlled trial

Introduction: Resuscitation goals for septic shock remain controversial. Despite the normalization of systemic hemodynamic variables, tissue hypoperfusion can still persist. Indeed, lactate or oxygen venous saturation may be difficult to interpret. Our hypothesis was that a gastric intramucosal pH-guided resuscitation protocol might improve the outcome of septic shock compared with a standard approach aimed at normalizing systemic parameters such as cardiac index (CI). Methods: The 130 septic-shock patients were randomized to two different resuscitation goals: CI ≥ 3.0 L/min/m2 (CI group: 66 patients) or intramucosal pH (pHi) ≥ 7.32 (pHi group: 64 patients). After correcting basic physiologic parameters, additional resuscitation consisting of more fluids and dobutamine was started if specific goals for each group had not been reached. Several clinical data were registered at baseline and during evolution. Hemodynamic data and pHi values were registered every 6 hours during the protocol. Primary end point was 28 days' mortality. Results: Both groups were comparable at baseline. The most frequent sources of infection were abdominal sepsis and pneumonia. Twenty-eight day mortality (30.3 vs. 28.1%), peak Therapeutic Intervention Scoring System scores (32.6 ± 6.5 vs. 33.2 ± 4.7) and ICU length of stay (12.6 ± 8.2 vs. 16 ± 12.4 days) were comparable. A higher proportion of patients exhibited values below the specific target at baseline in the pHi group compared with the CI group (50% vs. 10.9%; P < 0.001). Of 32 patients with a pHi < 7.32 at baseline, only 7 (22%) normalized this parameter after resuscitation. Areas under the receiver operator characteristic curves to predict mortality at baseline, and at 24 and 48 hours were 0.55, 0.61, and 0.47, and 0.70, 0.90, and 0.75, for CI and pHi, respectively. Conclusions: Our study failed to demonstrate any survival benefit of using pHi compared with CI as resuscitation goal in septic-shock patients. Nevertheless, a normalization of pHi within 24 hours of resuscitation is a strong signal of therapeutic success, and in contrast, a persistent low pHi despite treatment is associated with a very bad prognosis in septic-shock patients.Facultad de Ciencias Médica

Gastric tonometry versus cardiac index as resuscitation goals in septic shock: A multicenter, randomized, controlled trial

Introduction: Resuscitation goals for septic shock remain controversial. Despite the normalization of systemic hemodynamic variables, tissue hypoperfusion can still persist. Indeed, lactate or oxygen venous saturation may be difficult to interpret. Our hypothesis was that a gastric intramucosal pH-guided resuscitation protocol might improve the outcome of septic shock compared with a standard approach aimed at normalizing systemic parameters such as cardiac index (CI). Methods: The 130 septic-shock patients were randomized to two different resuscitation goals: CI ≥ 3.0 L/min/m2 (CI group: 66 patients) or intramucosal pH (pHi) ≥ 7.32 (pHi group: 64 patients). After correcting basic physiologic parameters, additional resuscitation consisting of more fluids and dobutamine was started if specific goals for each group had not been reached. Several clinical data were registered at baseline and during evolution. Hemodynamic data and pHi values were registered every 6 hours during the protocol. Primary end point was 28 days' mortality. Results: Both groups were comparable at baseline. The most frequent sources of infection were abdominal sepsis and pneumonia. Twenty-eight day mortality (30.3 vs. 28.1%), peak Therapeutic Intervention Scoring System scores (32.6 ± 6.5 vs. 33.2 ± 4.7) and ICU length of stay (12.6 ± 8.2 vs. 16 ± 12.4 days) were comparable. A higher proportion of patients exhibited values below the specific target at baseline in the pHi group compared with the CI group (50% vs. 10.9%; P < 0.001). Of 32 patients with a pHi < 7.32 at baseline, only 7 (22%) normalized this parameter after resuscitation. Areas under the receiver operator characteristic curves to predict mortality at baseline, and at 24 and 48 hours were 0.55, 0.61, and 0.47, and 0.70, 0.90, and 0.75, for CI and pHi, respectively. Conclusions: Our study failed to demonstrate any survival benefit of using pHi compared with CI as resuscitation goal in septic-shock patients. Nevertheless, a normalization of pHi within 24 hours of resuscitation is a strong signal of therapeutic success, and in contrast, a persistent low pHi despite treatment is associated with a very bad prognosis in septic-shock patients.Facultad de Ciencias Médica

Effects of hemorrhage on gastrointestinal oxygenation

Objectives: (1) To demonstrate that metabolic parameters are better indicators of tissue hypoxia than regional and whole oxygen consumption (VO2). (2) To compare intramucosal pH (pHi) in different gastrointestinal segments. Design: Prospective, interventional study. Setting: Research laboratory at a university center. Subjects: Fourteen anesthetized, mechanically ventilated dogs. Interventions: Twenty milliliters per kilogram bleeding. Measurements and main results: We placed pulmonary, aortic and mesenteric venous catheters, and an electromagnetic flow probe in the superior mesenteric artery, and gastric, jejunal and ileal tonometers to measure flows, arterial and venous blood gases and lactate, and intramucosal PCO2. We calculated systemic and intestinal oxygen transport (DO2) and consumption (VO2), pHi and arterial minus intramucosal PCO2 (ΔPCO2). Then, we bled the dogs and repeated the measurements after 30 min. Systemic and intestinal DO2 fell (26.0±7.3 versus 8.9±2.6 and 71.9±17.3 versus 24.6±9.6 ml/min per kg, respectively, p<0.0001). Systemic and intestinal VO2 remained unchanged (5.5±1.3 versus 5.4±1.3 and 15.7±5.0 versus 14.9±5.3 ml/min per kg, respectively). Gastric, jejunal and ileal pHi (7.13±0.11 versus 6.96±0.17, 7.18±0.06 versus 6.97±0.15, 7.12±0.11 versus 6.94±0.14, p<0.05) and ΔPCO2 (21±13 versus 35±23, 15±5 versus 33±16, 23±17 versus 38±20, p<0.05) changed accordingly. Arterial and mesenteric venous lactate and their difference, rose significantly (1.7±0.9 versus 3.7±1.4 and 1.8±0.8 versus 4.3±1.5 mmol/l, 0.1±0.6 versus 0.6±0.7 mmol/l, p<0.05). Conclusions: During hemorrhage, systemic and intestinal VO2 remained stable. However, hyperlactatemia and intramucosal acidosis evidenced anaerobic metabolism. pHi changes paralleled in the three intestinal segments.Facultad de Ciencias Médica

Use of a dual lumen cannula for venovenous extra corporeal membrane oxygenation in a patient with acute respiratory distress syndrome and a previously inserted inferior vena cava filter: a case report

RESUMO A oxigenação por membrana extracorpórea é utilizada em casos de hipoxemia refratária em diversas condições clínicas. Pacientes vítimas de traumatismo torácico geralmente desenvolvem síndrome da angústia respiratória aguda. Em razão do elevado risco de sangramentos, as complicações trombóticas que se apresentam neste contexto são particularmente difíceis de tratar e, geralmente, demandam a inserção de um filtro na veia cava inferior, com a finalidade de prevenir a migração de êmbolos oriundos das veias distais para a circulação pulmonar. Neste artigo, apresentamos o caso de um paciente com traumatismo torácico, que apresentou grave síndrome de angústia respiratória aguda, com necessidade de utilizar oxigenação por membrana extracorpórea aplicada por meio da introdução de uma cânula com duplo-lúmen na veia jugular interna direita. Este procedimento foi realizado tendo em vista a prévia inserção de um filtro na veia cava inferior, por conta da ocorrência de trombose venosa profunda em ambas as panturrilhas

End-tidal CO<SUB>2</SUB> pressure determinants during hemorrhagic shock

Objectives: To examine the relationship between end-tidal CO2 (PETCO2) and its physiological determinants, pulmonary blood flow (cardiac output, CO) and CO2 production (VCO2), in a model of hemorrhagic shock during fixed minute ventilation. Design and setting: Prospective, observational study in a research laboratory at a university center. Subjects and interventions: Six anesthetized, intubated, and mechanically ventilated mongrel dogs. Progressive stepwise bleeding. Measurements and results: We continuously measured PETCO2 with a capnograph, pulmonary artery blood flow with an electromagnetic flow probe, arterial oxygen saturation (SaO2) with a fiberoptic catheter, and oxygen consumption (VO2) and VCO2 by expired gases analysis. Oxygen delivery (DO2) was continuously calculated from pulmonary blood flow and SaO2. We studied the correlation of PETCO2 with CO and VCO2 in each individual experiment. We also calculated the critical point in the relationships PETCO2/DO2 and VO2/DO2 by the polynomial method. As expected, PETCO2 was correlated with CO. The best fit was logarithmic in all experiments (median r 2=0.90), showing that PETCO2 decrease is greater in lowest flow states. PETCO2 was correlated with VCO2, but the best fit was linear (median r 2=0.77). Critical DO2 for PETCO2 and VO2 was 8.0±3.3 and 6.3±2.5 ml.min–1.kg–1, respectively (NS). Conclusions: Our data reconfirm the relationship between PETCO2 and CO during hemorrhagic shock. The relatively greater decrease in PETCO2 at lowest CO levels could represent diminished CO2 production during the period of VO2 supply dependency.Facultad de Ciencias Médica