快樂小藥師 Im pharmacist nichts glücklich

Dialysis disequilibrium syndrome：

一般利用mannitol來預防洗腎時DDS，尤其是老人家、中風、metabolic acidosis的病人要特別小心。DDS通常發生在洗腎中或到洗完，病人會頭痛、吐、或cramps seizure，甚至conscious change。但是病人洗完腎，發生conscious change絕對不可以說是DDS，因為這個診斷是by rule out。在標準處置下，是很少發生嚴重的disequilibrium syndrome，就算有也不會持續太久。所以如果病人中午洗腎，到晚上conscious change，應該照一張brain CT去排除brain hemorrhage。

Disequilibrium syndrome的原因與brain edema有關，開始洗腎時，BUN被洗掉，plasma osmolality降低，但brain cell的osmolality仍高。所以水份會shift to brain cell。有人提出反駁，BUN是可以自由進出cell "ineffective" osmole，但是這種effect要花好幾個小時，而我們開始洗腎只在二個小時，所以BUN還是一種relative "effective osmole"。有人作過study，BUN↓53%時，brain BUN只下降13%，所以BUN這個理論，仍然是被接受的。另外JCI 96年提出，這可能和intracerebral acidosis有關係。他們認為因為未知的機轉，細胞內pH值會降低，導致Na，K，進入cell，增加cellular osmolality這個理論，目前並沒有實驗證明。

DDS要怎麼治療：blood flow要慢，時間要短，要加manitol，真的要吊很多水，可以採用sequential的方式。 另外許多和hypotension有關的etiology，當H/D病人血壓降低時，我們可以作的是：把ultrafiltration關掉，把病人放低（Trendelenburg position），Blood flow變慢，如果血壓降得很低，可以給一點Mannitol和Saline。 Prevention：不要掉太乾，ultrafiltration要適可而止，真得掉得很低的話，用sequential的方法，就是前二小時，我們純掉水，所以plasma osmolality上升，使細胞內液shifting到血管中，減少血壓降低，我們也可以使用高鈣低溫透析液，correct anemia等來改善cardiovascular performance，減少洗腎時食物的intake。建議病人喝咖啡，因為它可以拮抗adenosine，都可以減少hypotension的效果。
若mannitol用在低血壓，mannitol (0.5-1.0g/kg)

 以下是Micromedex的資料：
Subdural hematoma
High-dose MANNITOL administered pre-operatively was associated with improved clinical outcomes compared with conventional-dose mannitol in hospitalized patients with ACUTE SUBDURAL HEMATOMA, based on a randomized, controlled trial (n=178). All patients received a conventional dose of mannitol (approximately 0.6 to 0.7 gram/kilogram (kg)) via fast intravenous infusion, along with intravenous infusion of normal saline solution to prevent hypotension. Subdural hematoma patients were randomized to a control group (n=87), which received no more mannitol, or to a mannitol treatment group (n=91) which received an additional preoperative dose of mannitol of approximately 0.6 to 0.7 gram/kg in the absence of pupillary widening via fast intravenous infusion (patients with pupillary widening received mannitol 1.2 to 1.4 grams/kg). The mannitol group also received additional saline solution (Cruz et al, 2001).

Raised intracranial pressure
1)  Intravenous bolus doses of 0.25 to 1 gram/kilogram have been effective in controlling increased intracranial pressure after severe traumatic brain injury. Serum osmolarity should be maintained below 320 milliosmoles/liter (Bullock et al, 2000)
2)  Investigators evaluated empiric versus intracranial pressure monitoring-based dosing of mannitol in a randomized trial involving 77 patients with head injuries, and found no significant difference in outcomes of the 2 groups. The empirically treated patients received a bolus of 50 grams initially or 0.75 gram/kilogram (g/kg) if the patient weighed less than 70 kg and then received 0.25 g/kg every 2 hours up to a serum osmolality of 310 milliosmols/L. The group dosed by monitoring of intracranial pressure also received the initial bolus of 50 grams, but received the bolus dose only when intracranial pressure reached 25 millimeters mercury. Empirically treated patients maintained a lower mean highest intracranial pressure than those who were treated only when their intracranial pressure reached 25 mmHg (Smith et al, 1986).
3)  A continuous infusion of mannitol is not recommended due to the generation of intracellular ions by brain-cells which creates an osmotic equilibrium at a higher osmolality without adequate reduction in brain volume (Loughhead, 1988a).

兒科使用
Raised intracranial pressure