探討犬隻經由留置針抽血的可行性

Abstract

對於重症以及住院的病患，臨床獸醫師會定期的以血液學檢查評估患者的狀態、制定適合的治療計畫、以提供適當的照顧。由靜脈穿刺抽血是臨床上最傳統的方式，也被認為是最佳的抽血途徑。由於入針時會伴隨著疼痛和不適，因此從周邊靜脈留置針抽血可能是可以考量的替代方式。此方法除了可以減少反覆穿刺對靜脈的創傷、減少可能出現的瘀青和血腫、還可以降低病患的身心壓力。雖然有越來越多人醫的急診醫師們會以留置針進行病患的血液採樣，但是目前針對留置針抽血的相關研究還不明確，在獸醫的臨床文獻更是有限。因此，本篇研究的目的在於比對經由兩種途徑抽血的血液數值，分析探討經由留置針抽血是否可以作為靜脈穿刺抽血的替代途徑。 本篇是一篇隨機、前瞻性、關於方法比較上的研究。納入研究的條件為需要血檢，以及需要放置靜脈留置針的犬隻。分別會從雙側的頭靜脈以不同的方式抽取血液樣本進行平行比對分析。當經由留置針抽血時，為了避免點滴稀釋的影響，因此需先抽取留置針內的點滴液體丟棄 (約300% 的死腔)，再進行血液樣本的抽取做完整的血液檢查。總共評估19項的血液數值，其中也包含全血球計數 (CBC)、血清生化數值 (SB) 和電解質分析。每一對樣本之間的誤差將與美國獸醫臨床病理學會 (ASVCP) 所發表的總允許誤差 (cTEa) 去做合理比較。並會以不同的統計軟體進行多重交叉比對。 共有55 對樣本納入本研究，並依照血清顏色依序分類成30 對「透明」、13對「脂血」、以及12 對「溶血」樣本。結果顯示，統計上，「透明」和「脂血」組裡，對於CBC 的各項指數均無顯著差異。而HB 和HCT 則會因溶血而有顯著影響。相較於CBC 在統計學上的一致性，生化在分析上有較多顯著性差異。在「透明」組裡，ALB、ALKP、AST、BUN、CREA、GLU、TP、K+ 和 CL- 均有顯著誤差。「脂血」組裡, 有顯著差別的有ALB、ALKP、GLU、TP 和NA+。以及ALKP，ALT 和AST 在「溶血」組裡也顯著不同。然而，當進行進一步回顧性的各組比對時，統計學存有的顯著誤差上均不會對臨床覺應造成影響。 因鉀和血糖是重要的生化指標，任何偏差都有可能會影響臨床決策。因此，在需要嚴格監控鉀離子以及血糖的患者上，對於經由留置針採取的樣本仍需以客觀的方式進行數據判讀。 總結來說，經由留置針抽出的血液樣本普遍上都是可被接受的，是一個靜脈穿刺的有效替代途徑。然而當檢驗結果接近參考值上下限時，臨床醫師們可能需考量以靜脈穿刺重新抽取血液樣本作為確認指標。

In circumstances where patients require intensive care and/or prolonged hospitalization, blood tests are routinely performed for the clinicians to evaluate a patient’s status, establish subsequent treatment plans and ensure ongoing, proper patient management. Direct venipuncture (DV) is a traditional, well-recognized optimal method for blood sampling. However, as DV is invasive and painful, drawing blood from a peripheral intravenous catheter (PIVC) can therefore be an alternative, as it causes less traumatic entries to veins and minimizes patient discomfort, bruising and distress. Despite the increasing use of PIVCs for blood sampling in emergency settings in human medicine, there is; however, a current research gap in comparing the effectiveness of blood sampling from PIVCs to venipuncture, especially in veterinary medicine. Hence, this study aimed to (1) compare the hematology and biochemistry profiles between the two blood collection techniques, and most importantly, (2) investigate if blood sampling from PIVCs can be an alternative to direct venipuncture (DV). This was a randomized, prospective, method-comparison study. Blood samples were collected from client-owned dogs that required a blood test and a PIVC. Paired DV and PIVC samples were collected from the contralateral cephalic veins. Pre-samples (300% of the dead space) from PIVCs were discarded to minimize the dilution effects from infusions. 19 commonly measured laboratory analytes were evaluated respectively, including complete blood counts (CBC), serum biochemistry panels (SB) and electrolytes levels. Each paired sample was further compared to the consensus total allowable error (cTEa) values that were previously published by the American Society for Veterinary Clinical Pathology (ASVCP) community. The sample pairs were also analyzed for agreement and bias with a variety of statistical methods. Data analysis was performed on a total of 55 paired samples, which were classified into 3 sub-groups according to the serum colors. 30 pairs were “clear”, 13 pairs were “lipemic” and 12 pairs were “hemolytic”. Results showed that there was no statistically significant bias in CBC analytes in the “clear” and “lipemic” groups. However, statistically significant biases were identified in HB and HCT in the “hemolytic” group. Upon the evaluations of serum biochemistry, several statistically significant biases were identified. Statistically significant biases were observed in ALB, ALKP, AST, BUN, CREA, GLU, TP, K+ and GLU in the “clear” group. In the “lipemic” group, statistically significant biases were observed in ALB, ALKP, GLU, TP and NA+, and finally, ALKP, ALT and AST were statistically significant in the “hemolytic” group. When statistically differences were identified, these were subjectively reviewed and were not clinically significant. As potassium (K+) and blood glucose (GLU) play critical roles in homeostasis and cellular functions, any difference between measurements may be clinically important. Results from this study emphasized the importance of interpretations on K+ and GLU, and most importantly, for patients that required a tight control of K+ and GLU, blood samples from the PIVCs should be used with cautions. Ultimately, blood sampling from PIVCs can produce generally acceptable results and be an effective alternative to DV sampling. Nevertheless, for results that are close to either end of a reference interval (RI), careful reassessments on the patients or re-samplings of blood samples via DVs should be considered.