to the extent怎么理解？

Case 2:A 25-year-old man with a 10-year history of type 1 diabetes mellitus becomes anorexic after developing gastroenteritis and reducing his insulin dose. He then develops nausea, vomiting, polyuria, and dyspnea and presents to the ED. The patient also has a long history of depression and is takingfluoxetine. He has orthostatic hypotension. His breath has a fruity odor. The initial laboratory studies reveal SUN, 40 mg/dL; creatinine, 1.5 mg/dL; glucose, 800 mg/ 100 mL; [Na+], 120 mEq/L; [Cl−], 75 mEq/L; [HCO3−], 12 mEq/L; K+, 3.0 mEq/L; ([AG], 32 mEq/L); and albumin, 4.0 g/100 mL. The measured osmolality is 330 mOsm/L; serumβ-hydroxybutyrate,>8 mEq/L; and urine ketones, 3+by dipstick. Blood ethanol level is nondetectable. ABG values are pH 7 .16; PO2, 90 mm Hg; pCO2, 35 mm Hg; and [HCO3−], 12 mEq/L.

病例2：一名25岁男性，10年1型糖尿病病史，胃肠炎并减少胰岛素剂量后出现厌食症。然后恶心、呕吐、多尿和呼吸困难，就诊于急诊科。患者亦有长期的抑郁症病史，正服用氟西汀。直立性低血压，呼气有一股水果味。最初的实验室检查结果显示:SUN：40mg/dl、肌酐：1.5mg/dl、葡萄糖：800mg/100ml、[Na⁺]：120mEq/L、[Cl^-]：75mEq/L、[HCO₃⁻]：12mEq/L、K⁺：3.0mEq/L([AG]：32mEq/L)、白蛋白：4.0g/100ml。测定的渗透压为330毫升/升，血清β-羟基丁酸酯>8mg/L、尿酮为3。血液中酒精浓度检测不到。ABG(动脉血气)示pH值7.16、PO₂ 90mmHg、PCO₂:35 mmHg、[HCO₃⁻]：12mEq/L。

What is his acid-base disorder?

a)HAGMA due to diabetic ketoacidosis (DKA)

b)HAGMA due to DKA and metabolic alkalosis

c)HAGMA due to DKA, metabolic alkalosis, and respiratory acidosis

d)HAGMA due to DKA and hyperchloremic acidosis

他的酸碱紊乱是什么？

a ）糖尿病酮症酸中毒(DKA)所致HAGMA

b ）DKA和代谢性碱中毒所致HAGMA

c ）DKA、代谢性碱中毒和呼吸性酸中毒所致HAGMA

d ）DKA和高氯酸中毒所致HAGMA

This patient’s history, examination, and initial laboratory studies were entirely consistent with DKA. This form of HAGMA is due to the ECF accumulation of the 2 “ketoacids” (β-hydroxybutyric acid and acetoacetic acid). When the concentration of these 2 acids increases, the [HCO3−] falls reciprocally, and the [AG] increases. At the time of admission, patients with DKA have an average “delta/delta” orΔ[AG]/Δ[HCO3−] ratio of about 1. However, to the extent that ketoacid anions are excreted into the urine, together with sodium and potassium ions, this will reduce the [AG] and partially convert the metabolic acidosis from a HAGMA to a hyperchloremic acidosis. This phenomenon usually develops after hospitalization, as the patient’s volume status is re-expanded with NaCl-containing intravenous fluids, and kidney function improves.

该患者的病史、检查和初步实验室检查完全符合DKA。DKA的HAGMA是由于ECF积累了两种“酮酸”(β-羟基丁酸和乙酰乙酸)。当这两种酸的浓度增加时，[HCO₃⁻]下降，[AG]增加。在入院时，DKA患者Δ[AG]/Δ[HCO₃⁻]比值约为1。然而，如果酮酸阴离子与钠、钾离子一起从尿液中排泄，这将降低[AG]，并将部分HAGMA性代谢性酸中毒从转化为高氯性酸中毒。这种现象通常发生在住院后，患者的容量状态因输注含氯化钠的液体重新扩张，肾功能改善。

网络上To the extent (that) 有四种译法：

Ø  to the extent practicable，在切实可行的范围内

Ø  就......而言

Ø  except to the extent，除了......之外

Ø  如果，若......

to the extent怎么理解？谢谢

If we assume his baseline [AG] was 10 and his baseline [HCO3−] was 24; then his [AG] increased by 23, from 10 to 33 and his [HCO3−] fell by 12, from 24 to 12 (all mEq/L). Thus, hisΔ[AG], or [AG] increase, far exceeded the fall in his [HCO3−]; that is, hisΔ[AG]/Δ[HCO3−] w a s >>1. Consequently, we must assume that either additional bicarbonate was generated during the illness or that his initial [HCO3−] was not normal, but instead was already increased to about 34 mEq/L when the DKA developed. This patient reported that he had been vomiting so gastric metabolic alkalosis was the likely etiology of a high [HCO3−]. Whenever theΔ[AG] increase markedly exceeds theΔ[HCO3−] decrease, this suggests coexisting HAGMA and metabolic alkalosis (or less commonly HAGMA and chronic respiratory acidosis, which increases the [HCO3−] due to a compensatory response).

如果我们假设他的[AG]基线是10，[HCO₃⁻]基线是24，那么他的[AG]从10增加到33，增加了23，[HCO₃⁻]从24下降到12(单位均为mEq/L)，下降了12。因此，他的Δ[AG]或[AG]增加量远远超过了他的[HCO₃⁻]下降量，也就是说他的Δ[AG]/Δ[HCO₃⁻]远远>>1。因此，我们必须假设，要么是疾病治疗期间产生了额外的碳酸氢盐，要么是他最初的[HCO₃⁻]不正常，因而在DKA发生时已经增加到约34mEq/L。这位患者主诉他一直在呕吐，所以胃代谢性碱中毒可能是高[HCO₃⁻]的病因。当Δ[AG]升高明显超过Δ[HCO₃⁻]降低时，这提示HAGMA和代谢性碱中毒共存(或不常见的HAGMA和慢性呼吸性酸中毒，由于代偿性反应导致[HCO₃⁻]升高)。

怎么就产生了额外的碳酸氢盐，碳酸氢盐明明是下降的，34mEq/L这个数字从哪里来？

Now consider this patient’s degree of respiratory compensation. His [HCO3−] was 12 mEq/L and the Winters equation predicts that his PaCO2should be about 26 mm Hg. However, this patient’s PaCO2was 35 mm Hg, which is too high. This indicates respiratory acidosis exists in addition to his HAGMA and metabolic alkalosis. Hypokalemia may have produced respiratory muscle weakness. Therefore, this patient has a triple A-B disorder (HAGMA due to DKA, metabolic alkalosis due to vomiting, and respiratory acidosis probably due to hypokalemia) and the answer to question 2 is (c).

现在考虑一下这个患者的呼吸代偿程度。他的[HCO₃⁻]是12mEq/L，Winters方程预测他的PaCO₂应该在26mmHg左右。然而，这位患者的PaCO₂是35mmHg，太高了。这表明除HAGMA和代谢性碱中毒外，还存在呼吸性酸中毒。低钾血症可能导致呼吸肌无力。因此，这位患者患有A-B三联症(DKA引起的HAGMA，呕吐引起的代谢性碱中毒，以及可能是低钾血症引起的呼吸性酸中毒)，问题2的答案是(C)。