Development Of Severe Acidosis Research Articles

Treatment of Acute Liver Failure in Resource-Constrained Settings without Transplantation Facilities Can Be Improved.

Treatment of Acute Liver Failure in Resource-Constrained Settings without Transplantation Facilities Can Be Improved.

Heliox allows for lower minute volume ventilation in an animal model of ventilator-induced lung injury.

BackgroundHelium is a noble gas with a low density, allowing for lower driving pressures and increased carbon dioxide (CO2) diffusion. Since application of protective ventilation can be limited by the development of hypoxemia or acidosis, we hypothesized that therefore heliox facilitates ventilation in an animal model of ventilator–induced lung injury.MethodsSprague-Dawley rats (N=8 per group) were mechanically ventilated with heliox (50% oxygen; 50% helium). Controls received a standard gas mixture (50% oxygen; 50% air). VILI was induced by application of tidal volumes of 15 mL kg-1; lung protective ventilated animals were ventilated with 6 mL kg-1. Respiratory parameters were monitored with a pneumotach system. Respiratory rate was adjusted to maintain arterial pCO2 within 4.5-5.5 kPa, according to hourly drawn arterial blood gases. After 4 hours, bronchoalveolar lavage fluid (BALF) was obtained. Data are mean (SD).ResultsVILI resulted in an increase in BALF protein compared to low tidal ventilation (629 (324) vs. 290 (181) μg mL-1; p<0.05) and IL-6 levels (640 (8.7) vs. 206 (8.7) pg mL-1; p<0.05), whereas cell counts did not differ between groups after this short course of mechanical ventilation. Ventilation with heliox resulted in a decrease in mean respiratory minute volume ventilation compared to control (123±0.6 vs. 146±8.9 mL min-1, P<0.001), due to a decrease in respiratory rate (22 (0.4) vs. 25 (2.1) breaths per minute; p<0.05), while pCO2 levels and tidal volumes remained unchanged, according to protocol. There was no effect of heliox on inspiratory pressure, while compliance was reduced. In this mild lung injury model, heliox did not exert anti-inflammatory effects.ConclusionsHeliox allowed for a reduction in respiratory rate and respiratory minute volume during VILI, while maintaining normal acid-base balance. Use of heliox may be a useful approach when protective tidal volume ventilation is limited by the development of severe acidosis.

Extracorporeal Life Support Experiences of a New Congenital Heart Center in Turkey

Extracorporeal life support (ECLS) provides mechanical support following cardiac surgery when respiratory and cardiac failure occurs. We retrospectively reviewed medical records of patients who needed ECLS at a new congenital heart center in Turkey. Between December 2009 and February 2012, 616 congenital heart operations were performed. A total of 13 patients (seven female) underwent ECLS. The ages of the patients ranged between 16 days and 33 years. There were two neonatal, seven infant, three pediatric, and one adult congenital cases. Medos DPII ECLS system was used in all patients. Mean duration of ECLS was 6.2 ± 5.8 days (ranged from 29 h to 24 days). While central vascular access with aorta and right atrial cannulation was used in 11 patients, neck vessels were used in the other patients. Four patients (30.7%) weaned successfully from ECLS (two infant, two pediatric cases). Three of them had ECLS intraoperatively. In all patients, two (15.4%) were discharged from the hospital. One of them had mild neurologic deficit. Bleeding from the surgical and cannulation sites was the most common complication. Thrombus was detected in pump head and changed uneventfully in three patients. Arterial pH and lactate levels at the beginning of ECLS were significantly lower in patients who were successfully weaned from ECLS than nonsurvivors (P = 0.04 and P = 0.02, respectively). ECLS can be a lifesaving modality in the perioperative period. It may be more beneficial if ECLS is used before the development of severe acidosis and high lactate levels.

Some metabolic changes during human corneal organ culture.

In order to evaluate the changes in medium composition during closed system corneal organ culture at 30 degrees C, pH, pO2, glucose and lactate was measured 1 to 7, 14 and 28 days after incubation of a total of 49 human corneas. During organ culture pO2 decreased from 17.3 kPa to 8.8 kPa at day 28. The average oxygen consumption was initially 0.16 mumole/h/cm2, but decreased rapidly to an average of 0.04 mumole/h/cm2 during the first weeks of incubation. The glucose concentration fell from 5.1 mM to 0.25 mM after 28 days, and the lactate concentration rose from 2.5 mM to 11 mM. The concentration changes were for both substances highest during the first 14 days of organ culture. The pH fell from 7.36 to 6.64 after 28 days. These findings indicate that the cultured human cornea predominantly metabolizes glucose anaerobically, and that the metabolic activity decreases during incubation. The limiting metabolic factors for prolonging the culture period seem to be development of severe acidosis and glucose depletion in the medium.