Effects of pH on brain energetics after hypothermic circulatory arrest
| Autor: | Michael E. Stromski, Mitsuru Aoki, Miles Tsuji, Paul R. Hickey, Richard A. Jonas, James C. Fackler, Fumikazu Nomura, David Holtzman |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Pulmonary and Respiratory Medicine
Magnetic Resonance Spectroscopy Phosphocreatine Swine Intracellular pH Kidney Cerebral edema Body Temperature Phosphates Adenosine Triphosphate Oxygen Consumption Hypothermia Induced Medicine Animals Immature animal business.industry Brain Hypothermia Hydrogen-Ion Concentration medicine.disease Oxygen medicine.anatomical_structure Glucose Cerebral blood flow Regional Blood Flow Anesthesia Cerebrovascular Circulation Circulatory system Reperfusion Vascular resistance Heart Arrest Induced Lactates Swine Miniature Surgery Vascular Resistance medicine.symptom Cardiology and Cardiovascular Medicine business Acidosis Energy Metabolism Reperfusion injury |
| Zdroj: | The Annals of thoracic surgery. 55(5) |
| ISSN: | 0003-4975 |
| Popis: | The pH management that provides optimal organ protection during hypothermic circulatory arrest is uncertain. Recent retrospective clinical data suggest that the pH-stat strategy (maintenance of pH at 7.40 corrected to core temperature) may improve brain protection during hypothermic cardiopulmonary bypass with a period of circulatory arrest in infants. The impact of alpha-stat (group A) and pH-stat (group P) strategies on recovery of cerebral high-energy phosphates and intracellular pH measured by magnetic resonance spectroscopy (A, n = 7; P, n = 5), organ blood flow measured by microspheres, cerebral metabolic rate measured by oxygen and glucose extraction (A, n = 7; P, n = 6), and cerebral edema was studied in 25 4-week-old piglets undergoing core cooling and 1 hour of circulatory arrest at 15 degrees C. Group P had greater cerebral blood flow during core cooling (54.3% +/- 4.7% versus 34.2% +/- 1.5% of normothermic baseline, respectively; p = 0.001). The intracellular pH during core cooling showed an alkaline shift in both groups but became more alkaline in group A than in group P at the end of cooling (7.08 to 7.63 versus 7.09 to 7.41, respectively; p = 0.013). Recovery of cerebral adenosine triphosphate (p = 0.046) and intracellular pH (p = 0.014) in the initial 30 minutes of reperfusion was faster in group P. The cerebral intracellular pH became more acidotic during early reperfusion in group A, whereas it showed continuous recovery in group P. Brain water content postoperatively was less in group P (0.8075) than in group A (0.8124) (p = 0.05). These results suggest that compared with alpha-stat, the pH-stat strategy provides better early brain recovery after deep hypothermic cardiopulmonary bypass with circulatory arrest in the immature animal. Possible mechanisms include improved brain cooling by increased blood flow to subcortical areas, improved oxygen delivery, and reduction of reperfusion injury, as well as an alkaline shift in intracellular pH with hypothermia in spite of a stable blood pH. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|