Sharif Zain, Al-Alawi Mazen
Irish Higher Specialist Trainee, Royal College of Physicians of Ireland, Dublin, Ireland.
Our Lady's Hospital Navan, Navan, Ireland.
BMJ Case Rep. 2018 Jun 17;2018:bcr-2017-224090. doi: 10.1136/bcr-2017-224090.
A 22-year-old woman presented with symptoms and signs consistent with acute severe asthma. After significant doses of beta-agonist, she developed a significant lactic acidosis. Significant issues arose in this patient's history with regards to purchase of medications, compliance and follow-up with respiratory service. Beta-adrenergic receptors when stimulated have been hypothesised to increase lipolysis, producing free fatty acids, which inhibit the conversion of pyruvate to coenzyme A within the Krebs cycle. Additional pyruvate is generated through stimulation of glycolysis and glycogenolysis through simultaneous catecholamine surge. This increased pyruvate load is shunted through anaerobic glycolysis, producing increased lactate. Steroid use during an asthma attack enhances the beta-2 receptor sensitivity, further potentiating lactate production. The hyperadrenergic state in this young asthmatic likely resulted in pyruvate and therefore lactate rise and thus metabolic acidosis as mentioned before. This piece highlights a physiological phenomenon that may occur in the context of iatrogenic hyperadrenergism.
一名22岁女性出现了与急性重症哮喘相符的症状和体征。在使用了大剂量β受体激动剂后,她出现了严重的乳酸酸中毒。该患者在药物购买、依从性以及呼吸科随访方面存在重大问题。据推测,β肾上腺素能受体受到刺激时会增加脂肪分解,产生游离脂肪酸,而游离脂肪酸会抑制三羧酸循环中丙酮酸向辅酶A的转化。同时,儿茶酚胺激增会刺激糖酵解和糖原分解,从而产生更多丙酮酸。增加的丙酮酸负荷通过无氧糖酵解分流,导致乳酸生成增加。哮喘发作期间使用类固醇会增强β2受体敏感性,进一步促进乳酸生成。这位年轻哮喘患者的高肾上腺素能状态很可能导致丙酮酸进而乳酸水平升高,从而如前所述引发代谢性酸中毒。本文强调了一种可能在医源性高肾上腺素能状态下出现的生理现象。