[鈉與鉀]之17: 高血鉀 - 開始治療


以下依照時間順序,先處理最可能致命的狀況(1),然後快速把胞外的鉀藏進胞內(2),然後我們再減少攝取增加排除(3)真正減少身體裡的鉀

1. 用鈣拮抗高血鉀的cardiac effect
  • 機制:Action potential threshold↑, excitability↓
  • effect starts in 1~3mins,lasts for 30~60mins
  • Calcium gluconate(10% solution x 10cc,272mg/amp =0.68mmol/amp of elemental calcium),drug of choice但很可惜是健保無好藥的代表作
  • Calcium chloride(10% x 10cc,89mg/amp=0.22mmol/amp of elemental calcium),extravasation造成tissue necrosis因此建議使用central line
  • 注意: Ca不能和bicarbonate混和 → 會沉澱

2. 把K從胞外趕到細胞內(最快降鉀的方式)
  • Insulin and Glucose:首選
    1. Infusion: RI 10U in D10W 500mL,IVD for 60mins
      Bolus: RI 10U IVA followed by D50W 50mL(2amp左右)
    2. 起始10~20mins, peaks at 30~60mins, 持續4~6hrs
    3. 效果:K↓0.5~1.2 mmol/L
    4. 小心低血糖。75%病人在接受bolus regimen後一小時左右發生
  • β-agonist:建議和insulin/glucose合用
    1. 起始30mins, peaks at 90mins, 持續2~6hrs
    2. 效果:K↓0.5~1.0 mmol/L
    3. Synergism with insulin且可減少低血糖的發生
    4. 壞處:↑heart rate by 15.1±60 bpm(CAD的病人要小心)
    5. 20~40% of ESRD patients NOT responsive to albuterol。β2-agonists should not be used as a single agent to treat hyperkalemia.
  • Bicarbonate:Controversial
    1. Suggested ONLY in acidemia

3. 增加鉀從身體裡排出
  • Diuretics,尤其是在hyporenin hypoaldo的狀況,或有K secretory problems
  • 交換樹脂(Resins),效果很慢(頭24hr幾無作用),要避開服用其他陽離子如鈣或鎂 (競爭鉀離子交換)
    1. Na-cycled resins: Kayexalate (SPS, sodium polystyrene sulfonate )
      → Na吸收增加,小心volume overload
    2. Calcium-cycled resins: Kalimate
      → 小心hypercalcemia,此外也可能降磷
  • Dialysis,最快最有效,但也最侵入性風險最大
    1. 3~5hr的HD可移除 40~120 mmol的鉀,其中第一小時是移除最多最快的,第三小時後移除量就很有限了
    2. 血鉀和透析液落差太大,降鉀太快可能會增加arrhythmia和rebound hypertension的風險,尤其有在老人、有吃digoxin、Hx of arrhythmia、CAD、LVH、high SBP。
    3. Pre-treatment with β2–agonist, insulin and glucose, 或透析中吃東西會減少鉀被移除的效率(因為躲進細胞內),造成透析後K升高

4. Treatment of underlying conditions
所以前面的鑑別診斷找原因還是很重要的

5. 飲食和藥物調整



上一篇:[鈉與鉀]之16: 高血鉀 - 你聽過Pseudohypoaldosteronism嗎?


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