RESUMEN
Meconium aspiration syndrome causes respiratory failure after birth and in vivo monitoring of pulmonary edema is difficult. The objective of the present study was to assess hemodynamic changes and edema measured by transcardiopulmonary thermodilution in low weight newborn piglets. Additionally, the effect of early administration of sildenafil (2 mg/kg vo, 30 min after meconium aspiration) on this critical parameter was determined in the meconium aspiration syndrome model. Thirty-eight mechanically ventilated anesthetized male piglets (Sus scrofa domestica) aged 12 to 72 h (1660 ± 192 g) received diluted fresh human meconium in the airway in order to evoke pulmonary hypertension (PHT). Extravascular lung water was measured in vivo with a PiCCO monitor and ex vivo by the gravimetric method, resulting in an overestimate of 3.5 ± 2.3 mL compared to the first measurement. A significant PHT of 15 Torr above basal pressure was observed, similar to that of severely affected humans, leading to an increase in ventilatory support. The vascular permeability index increased 57 percent, suggesting altered alveolocapillary membrane permeability. Histology revealed tissue vessel congestion and nonspecific chemical pneumonitis. A group of animals received sildenafil, which prevented the development of PHT and lung edema, as evaluated by in vivo monitoring. In summary, the transcardiopulmonary thermodilution method is a reliable tool for monitoring critical newborn changes, offering the opportunity to experimentally explore putative therapeutics in vivo. Sildenafil could be employed to prevent PHT and edema if used in the first stages of development of the disease.
Asunto(s)
Animales , Humanos , Recién Nacido , Masculino , Agua Pulmonar Extravascular/efectos de los fármacos , Hipertensión Pulmonar/prevención & control , Síndrome de Aspiración de Meconio/tratamiento farmacológico , Piperazinas/administración & dosificación , Sulfonas/administración & dosificación , Vasodilatadores/uso terapéutico , Animales Recién Nacidos , Modelos Animales de Enfermedad , Pulmón/efectos de los fármacos , Pulmón/patología , Síndrome de Aspiración de Meconio/patología , Purinas/administración & dosificación , Sus scrofa , Factores de Tiempo , Termodilución/métodosRESUMEN
Meconium aspiration syndrome causes respiratory failure after birth and in vivo monitoring of pulmonary edema is difficult. The objective of the present study was to assess hemodynamic changes and edema measured by transcardiopulmonary thermodilution in low weight newborn piglets. Additionally, the effect of early administration of sildenafil (2 mg/kg vo, 30 min after meconium aspiration) on this critical parameter was determined in the meconium aspiration syndrome model. Thirty-eight mechanically ventilated anesthetized male piglets (Sus scrofa domestica) aged 12 to 72 h (1660 ± 192 g) received diluted fresh human meconium in the airway in order to evoke pulmonary hypertension (PHT). Extravascular lung water was measured in vivo with a PiCCO monitor and ex vivo by the gravimetric method, resulting in an overestimate of 3.5 ± 2.3 mL compared to the first measurement. A significant PHT of 15 Torr above basal pressure was observed, similar to that of severely affected humans, leading to an increase in ventilatory support. The vascular permeability index increased 57%, suggesting altered alveolocapillary membrane permeability. Histology revealed tissue vessel congestion and nonspecific chemical pneumonitis. A group of animals received sildenafil, which prevented the development of PHT and lung edema, as evaluated by in vivo monitoring. In summary, the transcardiopulmonary thermodilution method is a reliable tool for monitoring critical newborn changes, offering the opportunity to experimentally explore putative therapeutics in vivo. Sildenafil could be employed to prevent PHT and edema if used in the first stages of development of the disease.
Asunto(s)
Agua Pulmonar Extravascular/efectos de los fármacos , Hipertensión Pulmonar/prevención & control , Síndrome de Aspiración de Meconio/tratamiento farmacológico , Piperazinas/administración & dosificación , Sulfonas/administración & dosificación , Vasodilatadores/uso terapéutico , Animales , Animales Recién Nacidos , Modelos Animales de Enfermedad , Humanos , Recién Nacido , Pulmón/efectos de los fármacos , Pulmón/patología , Masculino , Síndrome de Aspiración de Meconio/patología , Purinas/administración & dosificación , Citrato de Sildenafil , Sus scrofa , Termodilución/métodos , Factores de TiempoRESUMEN
OBJECTIVE: To study the value of gastric intramucosal pH and gastric intraluminal PCO2 measurements to predict weaning outcome from mechanical ventilation. DESIGN: Prospective clinical study. SETTING: Intensive care medicine department of a university hospital. PATIENTS: Nineteen adult critically ill patients who were mechanically ventilated because of acute respiratory failure and were considered ready to be weaned. INTERVENTIONS: The patients were weaned with: synchronized intermittent mandatory ventilation plus positive end-expiratory pressure (SIMV+PEEP) or continuous positive airway pressure with pressure support ventilation (CPAP+PSV). A gastric tonometer was placed in all the patients. Tonometric, respiratory, and hemodynamic variables were measured during the weaning process. MEASUREMENTS: Hemodynamic variables, respiratory mechanics, pulmonary gas exchange, respiratory muscle force, spontaneous pattern of breathing, and the central control of breathing were recorded. Simultaneously, the intramucosal pH and gastric intraluminal PCO2 were measured. MAIN RESULTS: Eleven patients were successfully extubated and eight failed. The patients who failed showed higher values of mouth occlusion pressure, respiratory rate, and effective inspiratory impedance (mouth occlusion pressure/mean inspiratory flow). The intramucosal pH was initially 7.19 +/- 0.22 and decreased to 7.10 +/- 0.16 during the weaning process in patients who failed (p < .05). At the same time, the intramucosal pH showed a nonsignificant change from 7.36 +/- 0.07 to 7.32 +/- 0.07 in the patients who were successfully extubated. The intramucosal pH was statistically different when both groups were compared during the initial and the final evaluations (p < .05). For the initial evaluation, the sensitivity and specificity to predict weaning failure when the intramucosal pH was < or =7.30 were 0.88 (95% confidence interval [CI], 0.66-1) and 0.82 (95% CI, 0.59-1), respectively. The gastric intraluminal PCO2 was higher in patients who failed (p < .05). When gastric intraluminal PCO2 was . or =40 torr during the initial evaluation, weaning failure occurred with a sensitivity of 1 (95% CI, 0.31-1) and a specificity of 0.55 (95% CI, 0.26-0.84). CONCLUSIONS: Weaning failure was associated with gastric intramucosal acidosis. The intramucosal pH and gastric intraluminal PCO2 may be helpful to predict weaning outcome. Further controlled clinical trials in a larger group of patients are needed.
Asunto(s)
Dióxido de Carbono/sangre , Mucosa Gástrica/irrigación sanguínea , Mucosa Gástrica/fisiología , Insuficiencia Respiratoria/prevención & control , Desconexión del Ventilador , Adolescente , Adulto , Anciano , Femenino , Hemodinámica , Humanos , Concentración de Iones de Hidrógeno , Funciones de Verosimilitud , Masculino , Manometría , Persona de Mediana Edad , Presión Parcial , Mecánica Respiratoria , Sensibilidad y Especificidad , Circulación Esplácnica , Estadísticas no ParamétricasRESUMEN
BACKGROUND AND OBJECTIVES: The purposes of this study were to evaluate the tolerance, efficacy and safety of isovolemic erythrocytapheresis (EA) in nonanemic patients with hereditary hemochromatosis (HH), and to assess the usefulness of recombinant human erythropoietin (rHuEPO) associated with EA to reduce treatment duration. MATERIALS AND METHODS: In 10 asymptomatic patients with serum ferritin >400 microg/l, transferrin saturation >50%, and GPT elevation, EA with rHuEPO and folic acid was performed. RESULTS: Red cell indices, serum ferritin, and other iron metabolism parameters (serum iron, transferrin, and transferrin saturation); GPT and other laboratory data were considerably improved. CONCLUSION: This method offers better results in less time than traditional phlebotomy. EA with rHuEPO is an effective therapeutic alternative for patients with HH.