Pediatric size phlebotomy tubes and transfusions in adult critically ill patients: a pilot randomized controlled trial

Table 2 Factors influencing blood loss and anemia during the intervention period

Procedure	Pediatric tubes (n = 100)	Adult tubes (n = 100)	Absolute difference (95% CI)	Risk ratio (95% CI)
Use of an arterial line, n (%)	25 (25)	17 (17)	8 (− 4 to 20)	1.5 (0.9 to 2.6)
Use of a central venous catheter, femoral vein catheter, or peripherally inserted central catheter, n (%)	31 (31)	21 (21)	10 (− 3 to 23)	1.5 (0.9 to 2.5)
Anticoagulation or anti-platelet agents, n (%)	38 (38)	35 (35)	3 (− 11 to 17)	1.1 (0.8 to 1.6)
Renal replacement therapy, n (%)	17 (17)	18 (18)	− 1 (− 12 to 10)	1 (0.5 to 1.8)
Total number of blood tests per patient, median (IQR)^a
Hematology	2.0 (1–3)	2.0 (1–4)	0	0.8 (0.6 to 1.1)
Chemistry^b	5.0 (3–8)	4.0 (2–8)	NA	NA
Immunology	0 (0–1)	1.0 (0–1)	− 1	0.9 (0.7 to 1.4)
Coagulation	0 (0–1)	0 (0–1)	0	0.9 (0.4 to 1.8)
Lactate	1 (0–2)	0 (0–2)	1	1.1 (0.6 to 1.8)
Blood gasses	1 (0–3)	1 (0–4)	0	0.8 (0.5 to 1.3)
Blood culture bottles	0 (0–0)	0 (0–0)	0	1 (0.5 to 1.9)
Phlebotomy volume^c
Per participant per day, mL, median (IQR)	8.6 (4–18)	21.6 (15–31)	− 13	0.5 (0.4 to 0.6)
Total per participant, mL, median (IQR)	21 (7–38)	50 (27–100)	− 29	0.4 (0.3 to 0.6)
Total per participant as a percentage of their estimated blood volume, %, median (IQR)	0.4 (0.2–0.7)	1.1 (0.6–2.1)	− 0.7	0.3 (0.2 to 0.5)

CI confidence interval, IQR interquartile range, NA not applicable
^aThe mean (range) of the total number of tests per patient, pediatric tubes vs adult tubes, were as follows: hematology 2.7 (0–19) vs 3.2 (0–18), chemistry 8.1 (0–52) vs 6.1 (0–34), immunology 0.7 (0–5) vs 0.7 (0–5), coagulation 1.3 (0–16) vs 1.5 (0–31), lactate 1.8 (0–32) vs 1.6 (0–25), blood gasses 3.2 (0–61) vs 3.6 (0–30), and blood cultures 0.5 (0–6) vs 0.5 (0–4)
^bIn the pediatric tube group, the chemistry number is the number of tubes sent for testing. In this group, there was variable use of 1 or 2 tubes according to the type of chemistry test performed (as specified by the laboratory). Therefore, a comparison with the adult tubes group in regards to the number of chemistry tests was not possible
^cThe maximum volume of each tube was used in this calculation. In the pediatric tube group, the volumes were 0.5 mL for hematology, 0.6 mL for chemistries, and 2.5 mL for coagulation tests. In the adult tube group, the volumes were 5.5 mL for hematology, 5 mL for chemistries, and 3.8 mL for coagulation. Tube volumes for lactate, immunology, arterial blood gases, and blood cultures were 5 mL, 6.5 mL, 1 mL, and 10 mL, respectively

ISSN: 2055-5784