41.下列何者可能導致乳酸中毒（lactic acidosis）？①休克 ②癲癇 ③一氧化碳中毒 ④惡性腫瘤
(A)僅①③
(B)僅①②④
(C)僅②③④
(D)①②③④

複習生化時間XD
乳酸是無氧代謝的產物。
大量產生乳酸的原因基本上可以有下列幾種情況：

• 在無氧的情況下，身體細胞會進行無氧代謝，產生乳酸
• Pyruvate變太多，推動化學式同時往Lactate和Acetyl-CoA生成方向
• PDH有問題，所以化學式偏向往無氧呼吸的方向進行
• Lactate的代謝上產生問題

所以參考UpToDate，乳酸中毒能分成下列幾種：

Above Figure adopted from UpToDate

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這一題剛好我在考前有聽到Curious clinicians有一集Podcast在解釋
為什麼高劑量Albuterol會導致Lactic acidosis
所以我這題答案寫的還蠻肯定的XD

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參考資料：

1. Lehninger Principles of Biochemistry 8/e
2. UpToDate Causes of lactic acidosis

• Serum lactate levels are considered normal in healthy subjects at approximately 1 mEq/L (mmol/L). Hyperlactatemia is defined as a serum lactate greater than 2 mmol/L with lactic acidosis considered when serum lactate levels are greater than 4 mmol/L with concomitant acidosis.
• States of enhanced metabolic activity (eg, grand mal seizures, strenuous exercise, hyperthermia), decreased tissue oxygen delivery (eg, severe anemia, hypoxia, circulatory shock, carbon monoxide poisoning), or impaired oxygen utilization (eg, cyanide toxicity) are all associated with lactic acidosis. Impaired hepatic clearance of lactate, as seen in hypoperfusion states, liver failure, and alcohol intoxication, can also result in lactic acidosis.
• Leukocytes and neoplastic cells in general have high rates of glycolysis. In the case of a large tumor or tightly packed bone marrow, oxygenation can be decreased, favoring the accumulation of lactate. Lactic acidosis has been reported in patients with massive liver tumors, and it has been postulated that the liver uptake of lactate is decreased in these patients.

Ref. DiPiro’s Pharmacotherapy: A Pathophysiologic Approach, 12th Edition > Acid–Base Disorders