INTRODUCTION: Blood acidification by lactic acid infusion converts bicarbonate to CO2. This effect can be exploited to increase the transmembrane PCO2 gradient of an extracorporeal membrane lung, resulting in a significant increase of extracorporeal CO2 removal. Lactic acid, however, is an energetic substrate and its metabolism might increase total body CO2 production (VCO2), limiting the potential beneficial effects of this technique. The aim of our study was to compare VCO2 during isocaloric infusion of lactic acid or glucose. METHODS: Six pigs (45 +/- 5 kg) were sedated and mechanically ventilated. Estimated caloric needs were 2300--2400 Kcal/die (95--100 Kcal/h). A sequence of two steps lasting four hours each was performed: 1) Glucose, 97 kcal/h were administered as 50% glucose solution, and 2) Lactic Acid, ~48.5 kcal/h were administered as lactic acid and ~48.5 kcal/h as 50% glucose solution. This sequence was repeated three times with two-hour intervals. Every hour VCO2, arterial blood gases and lactate were measured. Blood glucose level was kept constant titrating an insulin infusion, ventilation was adjusted to maintain arterial PCO2 at 50mmHg, a normal value for our animal model. RESULTS: During Lactic Acid steps VCO2 increased less than 5% compared to the Glucose steps (282 vs. 269 ml/min, p < 0.05); blood glucose did not differ between the two groups (respectively 101 +/- 12 vs. 103 +/- 8 mg/dl). Arterial lactate was always lower than 3 mmol/L. Arterial pH was lower during Lactic-Acid steps (7.422 vs. 7.445, p < 0.05). CONCLUSIONS: Replacing 50% of the caloric input with lactic acid increased total CO2 production by less than 5% compared to an equal caloric load provided entirely by a 50% glucose solution.
|Titolo:||Infusion of 2.5 meq/min of lactic acid minimally increases CO2 production compared to an isocaloric glucose infusion in healthy anesthetized, mechanically ventilated pigs|
PESENTI, ANTONIO MARIA (Ultimo)
|Parole Chiave:||extracorporeal membrane-oxygenation; positive pressure ventilation; carbon-dioxide removal; lung transplantation; respiratory-failure; metabolism; lactate; dialysis; bridge|
|Settore Scientifico Disciplinare:||Settore VET/02 - Fisiologia Veterinaria|
|Data di pubblicazione:||11-nov-2013|
|Digital Object Identifier (DOI):||10.1186/cc13098|
|Appare nelle tipologie:||01 - Articolo su periodico|