何時該輸血? Indications and hemoglobin thresholds for red blood cell transfusion in the adult

2023-10-02 之前放xuite的輸血相關筆記已經查詢不到. 只好重寫.
|這篇主要是說血色素的問題.

在uptodate 上面的參考資料(uptodate是付費網站-需帳號密碼才能點全文)
1. 多數患者. 建議採取限制性(較嚴格)輸血策略. Hb 通常維持在 7-8 即可
2. 有些患者因貧血發生症狀, 可考慮輸血, 將血色素提升到 8 以上. 
3. 輸血之後 15 分鐘就可以抽血追蹤血色素濃度是否達標
4. 

(下面中文使用google翻譯)
成人紅血球輸注的指徵和血紅蛋白閾值
大多數穩定患者的限制性輸血策略— 對於大多數血流動力學穩定的內科和外科患者，我們建議使用限制性輸血策略（少輸血；以較低的血紅蛋白水平輸血[通常為 7至8 g/dL]；並以較低的目標血紅蛋白水平為目標），而不是自由輸血策略（給予更多血液；以較高的血紅蛋白水平輸血），如圖所示（算法 1 ）；這種做法是基於多項臨床試驗的結果（表2）。具體閾值是基於在臨床試驗中針對與患者最相似的人群確定的安全值。

有些患者在血紅素水平低於我們建議的閾值時仍不會出現貧血症狀；相反，較高血紅素水平的輸血通常適合有症狀的患者（請參閱下文『有症狀的患者』）。此外，基於閾值的輸血通常不適合需要大量輸血的患者。關於輸血的最終決定必須考慮病人的意願和臨床狀況。

只要患者沒有主動出血，就可以在輸血後 15 分鐘內評估輸血後血紅素水平。這種做法是基於研究，顯示輸血完成後 15 分鐘測量的數值與較長時間間隔測量的數值之間具有高度一致性。18,19 ]。
在證據不足以指導治療的情況下，使用 7 至 8 g/dL 閾值的主要例外情況包括：

●有症狀的患者可能會以較高的血紅素水平輸血來治療症狀。(請參閱下文『有症狀的患者』 )
●患有急性冠狀動脈綜合症(ACS)的患者可能需要更高的輸血閾值。(請參閱下文‘ACS(包括MI)’
) ●基於閾值的輸血不適合需要大量輸血的患者，例如在外傷或嚴重胃腸道出血的情況下。相反，考慮到血紅蛋白平衡的延遲和等待報告血紅蛋白水平的時間，估計的失血量和血流動力學狀態應該指導輸血。（看「大量輸血」和「成人創傷患者中度至重度出血的初步處理」。）
● 慢性輸血依賴性貧血，如鐮狀細胞疾病或地中海貧血。(請參閱“地中海貧血的治療”，關於‘定期輸血’一節)
●某些病例出現嚴重血小板減少症。(參見下文『腫瘤病人』 )

我們避免不必要的輸血的目標也指導我們
對於血流動力學穩定且不主動出血的患者一次輸一個單位的紅血球，而不是要求多個單位的做法[ 20 , 21 ] 。

Indications and hemoglobin thresholds for red blood cell transfusion in the adult
Restrictive transfusion strategy for most stable patients — For most hemodynamically stable medical and surgical patients, we recommend using a restrictive transfusion strategy (giving less blood; transfusing at a lower hemoglobin level [typically 7 to 8 g/dL]; and aiming for a lower target hemoglobin level) rather than a liberal transfusion strategy (giving more blood; transfusing at a higher hemoglobin level), as illustrated in the figure (algorithm 1); this practice is based on the results of multiple clinical trials (table 2). The specific threshold is based on the value established as safe in the clinical trial with the population that most closely resembles the patient.

Some patients will remain asymptomatic from anemia at hemoglobin levels that are lower than our recommended threshold; conversely, transfusion at a higher hemoglobin level is often appropriate for symptomatic patients (see 'Symptomatic patient' below). In addition, threshold-based transfusion generally is not appropriate for patients requiring massive transfusion. The final decision regarding transfusion must take into account the patient's wishes and clinical status.

Assessment of the post-transfusion hemoglobin level can be performed as early as 15 minutes following transfusion, as long as the patient is not actively bleeding. This practice is based on studies showing a high degree of concordance between values measured 15 minutes after completion of the transfusion versus longer intervals [18,19].
Major exceptions to the use of a threshold of 7 to 8 g/dL, where evidence is insufficient to guide therapy, include the following:
●Symptomatic patients may be transfused at higher hemoglobin levels to treat symptoms. (See 'Symptomatic patient' below.)
●Patients with acute coronary syndromes (ACS) may require higher thresholds for transfusion. (See 'ACS (including MI)' below.)
●Threshold-based transfusion is not appropriate for patients requiring massive transfusion, such as in the setting of trauma or serious gastrointestinal bleeding. Rather, estimated blood loss and hemodynamic status should guide transfusion given the delay for hemoglobin to equilibrate and time waiting for hemoglobin levels to be reported. (See "Massive blood transfusion" and "Initial management of moderate to severe hemorrhage in the adult trauma patient".)
●Chronic transfusion-dependent anemia, such as sickle cell disease or thalassemia. (See "Management of thalassemia", section on 'Regular transfusions'.)
●Certain cases of severe thrombocytopenia. (See 'Oncology patient' below.)
Our goal of avoiding unnecessary transfusion also guides our practice of transfusing one unit of RBCs at a time, rather than requesting multiple units, for a hemodynamically stable patient who is not actively bleeding [20,21]. Whenever possible, we also initiate or continue treatment of the underlying condition responsible for the anemia.