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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 29, No 6, November/December 2018
AFRICA
383
between transfused FFP units with CPB time (
r
=
0.2634,
p
=
0.0199) and RPC units (
r
=
–0.4654,
p
<
0.001) transfused.
Table 4 shows units of blood products transfused, according
to the RACHS categories. Platelets and cryoprecipitate were
given solely by anaesthetists. Only two (1.9%) patients had a
transfusion-free operation and they were in RACHS category 1.
The Kruskal–Wallis test showed a statistically significant
difference between median RPC, cryoprecipitate and platelet
units transfused between the RACHS categories (Table 5). A
post
hoc
Dunn’s test for the median RPC, cryoprecipitate and platelet
units transfused showed a statistically significant difference
between RACHS category 4 and the other three RACHS
categories (1, 2 and 3) (Table 6). Additionally, a statistically
significant difference was found between RACHS categories 3
and 1 for transfusion of platelet units (Table 6).
Taking into consideration the small sample size in RACHS
4, a further analysis of the RACHS categories into two groups
consisting of RACHS 1 and 2, and RACHS 3 and 4 was
undertaken, and we found similar results for platelets and
cryoprecipitate units (Table 7). The significant difference was
lost for RPCs.
The mean peri-operative haemoglobin levels according to
RACHS categories are shown in Fig. 1 and Table 8. There was
no significant difference in mean peri-operative haemoglobin
levels across the RACHS categories.
The median units of blood products by weight categories
are presented in Table 9. RPC, platelet and cryoprecipitate
units transfused were statistically significantly different across
the weight categories. A
post hoc
Dunn’s test was done to show
where the difference lay between weight categories with regard
to transfusion of cryoprecipitate and RPC units. It shows
differences predominantly between weight category
>
15 kg and
other categories, while differences in transfusion of platelet units
were between weight categories
<
6 kg and 6–15 kg (Table 10).
The blood-conservation strategies used were tranexamic acid,
cell salvage and ultrafiltration. A single blood-conservation
strategy was used in 36 (34.3%) patients and two strategies in
45 (42.9%). All three strategies were used in 16 (15.2%) patients,
while eight (7.6%) had no blood-conservation strategy used.
Discussion
This study was difficult to analyse because of multiple variables
influencing the use of peri-operative blood products, some of
which were not assessed. Guidelines to audit whether blood
products were appropriately transfused in paediatric cardiac
Table 7. Median blood product units per patient transfused
between two RACHS category
Products
RACHS 1+2 RACHS 3+4
Total
p-value
RPC
1 (1–1)
1 (1–1)
1 (1–1)
0.4359
FFP
0 (0–1)
0 (0–1)
0 (0–1)
0.5218
Platelets
0 (0– 0)
0 (0–1)
0 (0–1)
0.0162*
Cryoprecipitate
0 (0– 0)
0 (0–0)
0 (0–0)
0.0254*
*
p
<
0.05; RPC, red packed cells; FFP, fresh frozen plasma; RACHS, risk-
adjusted classification for congenital heart surgery.
Table 5. Median units of blood products per patient transfused,
by RACHS category
Products,
median (IQR)
RACHS
1
RACHS
2
RACHS
3
RACHS
4
Total
p
-value
RPC
1 (1–1) 1 (1–2) 1 (1–1) 2 (2–2) 1 (1–1)
0.03*
FFP
0 (0–0) 0.5 (0–1) 0 (0–1) 0 (0–0) 0 (0–1)
0.053
Platelets
0 (0–0) 0 (0–1) 0 (0–1) 1 (1–2) 0 (0–1) 0.0013*
Cryoprecipitate 0 (0–0) 0 (0–0) 0 (0–0) 1 (1–3) 0 (0–0) 0.0001*
*
p
<
0.05; RPC, red packed cells; FFP, fresh frozen plasma; RACHS, risk-
adjusted classification for congenital heart surgery.
Table 4. Units of blood products transfused
according to RACHS category
Products,
n
(%)
RACHS
1
RACHS
2
RACHS
3
RACHS
4
Total
RPC
Total
11 (9.9) 66 (59.5) 28 (25.2) 6 (5.4) 111 (100)
Anaesthetists
0 (0)
8 (7.2)
2 (1.8)
1 (0.9)
11 (9.9)
Perfusionists
11 (9.9) 58 (52.3) 26 (23.4) 5 (4.5) 100 (90.1)
FFP
Total
2 (3.4) 41 (70.7) 15 (25.7) 0 (0)
58 (100)
Anaesthetists
2 (3.4) 21 (36.2) 12 (20.7) 0 (0)
35 (60.3)
Perfusionists
0 (0)
20 (34.5) 3 (5.2)
0 (0)
23 (39.7)
Platelets (anaesthetists)
0 (0)
16 (51.6) 11 (35.5) 4 (12.9) 31 (100)
Cryoprecipitate (anaes-
thetists)
0 (0)
17 (60.7) 6 (21.4) 5 (17.9) 28 (100)
RPC, red packed cells; FFP, fresh frozen plasma; RACHS, risk-adjusted clas-
sification for congenital heart surgery.
Table 6.
Post hoc
Dunn’s test of blood product use
between RACHS categories
Product
Categories RACHS 4 RACHS 3 RACHS 2
RPC
RACHS 1
0.009*
0.321
0.302
Kruskal–Wallis
RACHS 2
0.018*
0.405
p
=
0.030*
RACHS 3
0.022*
Platelets
RACHS 1
0.001*
0.021*
0.065
Kruskal–Wallis
RACHS 2
0.005*
0.123
p
=
0.001*
RACHS 3
0.021*
Cryoprecipitate
RACHS 1
<
0.001*
0.256
0.349
Kruskal–Wallis
RACHS 2
<
0.001*
0.217
p
=
0.0001*
RACHS 3
<
0.001*
*
p
<
0.05; RPC, red packed cells; RACHS, risk-adjusted classification for
congenital heart surgery.
Pre-op Inital CPB Lowest CPB Last CPB First ICU
Peri-operative Hb (g/dl)
16
14
12
10
8
6
RACHS 1
RACHS 2
RACHS 3
RACHS 4
CPB, cardiopulmonary bypass; ICU, intensive care unit; RACHS, risk-adjusted
classification for congenital heart surgery; pre-op, pre-operative; Hb, haemoglobin
Fig. 1.
Peri-operative haemoglobins categorised by RACHS
categories.