二階國考內科複習：腎臟酸鹼/離子平衡

酸鹼/離子平衡

參考資料：First choice叢書

1. 呼吸酸鹼查原因

• 呼吸酸: COPD、呼吸肌無力(中樞、週邊、肌肉)、鎮靜劑
• 呼吸鹼: 低血氧、酸中毒、疼痛、焦慮、服用salicylates或methylxanthine

2. 呼吸/代謝酸鹼代償

[常數口訣]1.25,  0.75, 0.1, 0.3, 0.2, 0.4

3. 代謝酸→看AG

• 白蛋白太低要校正：AG+ (4- alb)x 2.5
• 高AG：
• 未測到陰離子↑：乳酸酮酸水楊酸/甲醇乙醇乙丙二醇異丙醇(osmoles↑OG>10)/鐵/尿毒
• 未測到陽離子↓：低鈣、低鉀、低鎂
• 需再評估是否合併normal anion gap 酸鹼異常：delta AG/ delta HCO3-
• 正常AG：
• GI流失HCO3-
• RTA(pH值遞減)
• type 1: 自體免疫→ distal tubule排酸降低，UAG>0，
• type 2: 尿蛋白破壞→proximal tubule不吸收HCO3-，FeHCO3->15%
• type 4: hypoaldosterone→ proximal tubule不製造NH3，UAG>0，高血鉀
• 其他：保鉀利尿劑、TPN、灌太多normal saline(高血氯)、吸食強力膠(馬尿酸)、cation exchange

4. 代謝鹼

• 太多鹼：Milk-Alkali Syndrome
• 流失酸、流失體液(secondary hyperaldosteronism->留鈉排鉀排氫)
• 流失鉀→代謝鹼 (灌水無效、Ucl>20)
• 高血壓： primary hyperaldosteronism (低renin/高aldo)
• 正常或偏低血壓
• Bartter’s- 低血鉀、低血鎂、高尿鈣 (類似furosemide)，可用NSAID
•  Gitelman’s- 低血鉀、低血鎂、低尿鈣(類似thiazide)
• 外來mineralcorticoid(低renin/低aldo)：Cushing’s , CAH, Licorice, Liddle’s etc.

5. 低血鈉

• 非低滲透壓：排除高血糖、高血脂、高蛋白
• 低滲透壓
• 體液多：給利尿劑
• 體液正常：應限水給高張NaCl
• SIADH (尿濃>100mOsm/kgH2O+ 血稀<275mOsm/kg)DDx: primary polydipsia (尿稀<100mOsm/kgH2O)
• Adrenal insufficiency(上游代償暴走-> ADH↑
•  Hypothyroidism(有效體液容積減少)
•   體液少：補充0.9%NaCl
• 補太快鈉離子：CPM，會四肢無力、吞嚥困難、聲音沙啞

6. 高血鈉

• 體液多：給D5W加利尿劑
• 體液正常
• 中樞型尿崩：給DDAVP兩小時後尿液滲透壓增加50%
• Complete: 尿超稀<300 mOsm/kgH2O
• Partial: 尿稀300~800 mOsm/kgH2O
• 腎性尿崩：給予thiazide、治療高血鈣或鋰鹽中毒
• 體液少：補充純水

7. 低血鉀

• Urine Na>25mEq/L，urine有濃縮，則可以開始計算TTKG
• >7, renal loss
• 高血壓：primary hyperaldosteronism(Conn’s) or renal artery stenosis
• 無高血壓：diuretics、Bartter’s、Gitelman’s
• <3, GI loss
• 治療注意：點滴不給糖水、鉀不能給太快(rebound hyperkalemia)
• 特別注意QT prolonged、增加毛地黃毒性(低鉀高鈣)
• Thyrotoxicosis periodic paralysis：Na/K 通道問題，四肢無力，一早起來最嚴重
• Hypokalemia periodic paralysis：Ca通道問題，四肢無力，常有家族史
• 其他K+再分佈的問題：製造新細胞中(如 治療惡性貧血、給GCSF)、低體溫、Barium毒性

8. 高血鉀

• 臨床常見最初心電圖：junctional bradycardia, tent T wave
• 腎功能異常   
• 腎功能正常
• 細胞內外shift
• Aldo低, renin低: 抑制renin 分泌(NSAID, b-blocker, cyclosporine, DM nephropathy)
• Aldo低, renin高: 無法產生aldosterone (ACEI, ARB, heparin, ketoconazole, Addison’s)
• 集尿管回收鈉受損：TMP、pentamidine、spironolactone副作用

9. 低血鈣

• 心電圖：QT prolonged (比較：低血鉀)、倒T
• 原因
• 低PTH(特別記：hypomagnesemia)
• 高PTH：Vit D/Ca2+攝取不夠、receptor有問題、骨鈣釋出受阻等等 (特別記：acute pancreatitis、post parathyroidectomy)

10.高血鈣

• 心電圖：QT shortened
• 原因：PTH↑> 惡性腫瘤(肺部squamous)> TB/sarcoidosis(高血磷)、使thiazide或鋰鹽

11. 血磷

• 鼓勵高蛋白飲食、給予neutral phosphate、處理PTH亢進

12. 高血磷

• 給鈣片結合磷、低磷飲食、甚至可透析治療

實戰課題Medical internship topic 6: Hyponatremia

Hyponatremia

1.      Def: <135mmol/L

2.      First DDx: rule out pseudo-hyponatremia

• Hypertonic: hyperglycemia?

Na在hyperglycemia時會降低，correct Na=Na + 1.4×(sugar－100)

• Isotonic : hyperlipidemia, hyperproteinemia?
• Another consideration: sample mixed with IV injection fluids?

3.      Hypotonic :

• Too much water? (beware of fluid retention)à do not give N/S, but restrict Na+ and water intake
• Not enough solutes? (beware of poor intake)à may give N/S

4.      Symptoms:

nausea and vomiting, headache, confusion, loss of energy and fatigue,

restlessness and irritability, muscle weakness, spasms or cramps, seizures, coma

5. Na supplement if needed

•  Rate of infusion is important
•  應補鈉總量（mmol）=[135-病人血Na+(mmol/L)]×體重(kg)×0.6~0.5
•  補鈉的速度不能超過4~6 mEq/L/hour，24 hrs內不能超過9 Eq/L

6. Monitoring

•   Urine output
•   Na recheck Q4H

腎臟科Nephrology random notes 02: Hypokalemia

Hypokalemia

1. K+ pool in body: 3500 mEq l (50 mmol/Kg), extracellular only 60~80 mEq

    Daily intake: 100 mEq

2. K+ balance:

- acute internal balance: transcellular; driving force (inward) including Na/K pump, Na/H exchange, beta 2 agonist, insulin, thyroid hormone

- chronic external balance: renal secretion ; K+ secretion = [K+ ]CCD x Flow rateCCD

- GI: (metabolic acidosis)diarrhea, laxative use, villous adenoma,  (metabolic alkalosis) NG drainage, vomiting

3. Definition 

- K+ <3.5 mEq/L in blood

- does no equal low K+ in sum 

4. Etiologies:

- Uk >30 mEq/ day, >15 mEq/L, TTKG>7 --> renal loss--> check BP, acid-base, Ucl

- Uk <25 mEq/ day, <15 mEq/L, TTKG<3 -->extrarenal loss

TTKG= (urine/plasma [K+ ])/(urine/plasma osmolality)

5.  Common manifestations
- Mild to moderate= 2.5~3.5 mEq, usually asymptomatic

- Arrhythmia ( U wave, QT interval↑, PVCs, VT, VF)

- Muscle cramps and weakness

- Polyuria

- n/v, ileus

- tendon reflex↓

6. Treatment

Lin SH, Halperin ML. Hypokalemia: a practical approach to diagnosis and its genetic basis. Curr Med Chem 2007; 14: 1551-65.
Kunin AS, Surawicz B, Sim EA. Decrease in serum potassium concentrations and appearance of cardiac arrhythmias during infusion of potassium with glucose in potassium-depleted patients. N Engl J Med 1962; 266: 228-33

↓ 1 mEq= 200 mEq total body loss
K+ 2.5~3.5 mEq↓: oral slow-K 40~100 mEq/day, no more than 20 mEq in one dose
K+ 2.5 mEq↓: IV K+ supplement, do not give over 40 mmol/L or 60 mmol/hour
Peripheral line: 20 mEq/L(max 40), 10 mEq/hr
Central line: 40 mEq/L(max 100), 20 mEq/hr~40mEq/hr

IV: DO NOT mix with dextrose solution metabolic acidosis:  use KHCO3, K+ citrate
metabolic alkalosis: use KCl
low phosphorous: use K+ phosphate

Potassium sparing diuretics: 
- amiloride
- triamterene
- spironolactone #1 BID or #2 QD with loop diuretics #1?

腎臟科Nephrology random notes 01

Nephrology random notes 01

1. Blood cells

- Hgb: RBC can remove NO in blood--> RBC infusion can elevate blood pressure

- Platelet decrease: cause-->drug?, infection? DIC? hematologic disease? autoimmune?

2. UTI

Urine analysis

           - pyuria+bacteriuria + symptoms?

           - no need to treat asymptomatic UTI in women except pregnant women 

           - check renal echo if UTI in men

           - Treatment:

                   *quinolone and Baktar not first line--> 

                    drug resistance carried by plasmids, save these drugs for MDR-TB; 

                   *Ceftriaxone has IM form for those who can not stay in the hospital for IV antibiotics

                   * yeast and candida--> can be viewed as normal colonies

                   * Proteus: may be related to stones

3. Proteinuria

- A/C ratio: DM, HTN patients wound check this.

- P/C ratio: generalized protein loss

4. BUN/Cr↑ (pre-renal azotemia) causes

- Breakdown: GI bleeding (RBC), trauma

- Sepsis

- High protein diet

- Steroid use

BUN↓ : may be related to liver function ↓

5. Oliguria----->AKI?

- Pre-renal: try hydration, but beware of heart, kidney, liver function, allergy

- Post-renal: try Foley tube insertion, DDx: stone, malignancy, BPH

- Renal: drug induced? use lasix

6. Skin turgor evaluation spots

- Axillary region

- Inguinal region

7. Diet and CKD in Taiwan

- Avoid: carambole , kiwi fruit, melons, papayas, brown rice, anchovy, salty soup

8.Shortness of breath

- Hypoxia: A/a gradient abnormal, ex. pulmonary edema(CO2 more soluable than O2)

- CO2 retention with muscle fatigue, ex. asthma, COPD

9. ABG/VBG in SOB patients with CKD

- Do not count anion gap because we still cannot differentiate whether metabolic acidosis is caused by infection or renal diseases

- RTA narrowly defined: RTA with normal Cr.

10.  Dialysis

- lung edema: refractory to diuretics

- pericarditis

-K+↑, EKG change(+), fail medical treatment (Cr high-->protect heeart, may not have EKG abnormality; can double-check K+ level if doubting hemolysis) 

- Uremia

- Intoxication: Ca2+, acylovir,aminophylline ,Benzodiazepam(x), with smaller molecular and less protein binding ability

- Elective: acidosis, anemia

- Uremic encephalopathy diagnosed by rule out, DDx: CVA, stroke, sepsis (BP drop after dialysis!)

High Cr without symptoms: This is a strong person ! XD

11. Spider angioma

- Estrogen↑ --> central arteriole, peripheral capillaries--> on liver cirrhosis 

12. Else

-  Imipenem: may induce seizure

-  Cardiac echo: IVS--> septum thickness, LVPW--> left ventricle thickness, concentric hypertrophy--> HTN related