Audit of RBC Transfusion in Premature Infants 2001

Dr Ho Hing Tung (Paediatrics)

Dr Sherman Lee (Clinical Audit)

Dr Raymond Chu (Haematology)

Pamela Youde Nethersole Eastern Hospital

Objectives To assess the compliance of RBC transfusion with new

guidelines 2001 To assess the effectiveness of new guidelines in reducing

the number of RBC transfusions in premature infants

Transfusion Guidelines Beforehand, RBC transfusion according to “Handbook of

Blood Transfusion for doctors & nurses PYNEH 1998 2nd

Ed.” New RBC transfusion guideline was implemented from

Jan 2001

Old Guidelines 1998 New Guidelines 2001

Hct < 40% or

Hb < 13 g/dl

Oxygen or ventilator dependent

Hct 40% Severe Respiratory Illness•Ventilator/CPAP, MAP >8 cmH2O

•FiO2 > 50%

•Severe congenital heart disease

with cyanosis/heart failure

Hct < 35% or

Hb < 10 g/dl

Symptomatic Hct 35% Moderate Respiratory Illness•Ventilator/CPAP, MAP 6-8 cmH2O

•FiO2 35-50%

Hct < 27% or

Hb < 8 g/dl

Asymptomatic Hct 30% •Respiratory disease requiring FiO2

25-35% / nasal cannula O2 1/8-1/4 L/min•CPAP/IPPV, MAP <6 cmH2O

•Sustained tachycardia (>180/min) or

tachypnoea (>80/min) for 24 hours•Apnoea/bradycardia 10/24 hours or 2

requiring bag mask ventilation•Cessation of weight gain x 4 days•Undergoing major surgery

Hct 20% •Asymptomatic

Blood loss of > 10% of blood volume Acute blood loss with shock

Method Inclusion criteria:

Inborn baby with birth weight 1500 g Date of birth from 1 Sep 1998 to 31 Aug 2001 Date of discharge from 1 Sep 1998 to 30 Oct 2001

Exclusion criteria: Babies not born in PYNEH All perinatal & neonatal deaths before discharge Infants required transfer out of hospital

Method Data collection – Retrospective

All neonatal RBC transfusion episodes were retrieved from blood bank

Selection of cases according to inclusion & exclusion criteria

Trace all old records Subgroup

BW < 1000 g BW 1001 – 1500 g

Data collection as listed

Data Collection Demographic

Name ID Sex Gestation Birth weight DOB DODay 14 DODischarge Length of stay Age attain 2.2 kg

Clinical First Hct % at birth Ventilation Days O2 Days

BPD (36 wks PCA) IVH ( G 3) ROP ( G 3) Total no./vol. Transfusio

n at 2 weeks & > 2 weeks to discharge

No. of donor exposure

Data Collection Compliance

Indication for transfusion Compliance

Old guideline New guideline

Data Analysis Using SPSS 9.0 Chi-square tests for discrete variables Student’s t tests for group means Linear regression for prediction estimation of transfusion Differences considered significant at a p value of < 0.05

Results No. of premature infants included

Total Transfused %

Before Sep 1998 – Dec 2000 45 28 62.2

After Jan 2001 – Aug 2001 25 8 32.0

Baseline CharacteristicsBW (g) 1000 1001 – 1250 1251 – 1500 Total

Number 12 14 10 36

Gestation (wk) 24 – 29 27 – 30 28 – 30 24 – 30

First Hct %

[mean(range)]

49

(40.7 – 60)

52.8

(45 – 59)

53.8

(40.7 – 60.7)

51.8

(40.7 – 60.7)

Length of Hospital Stay (d)

[mean(range)]

127

(74 – 273)

87

(64 –159)

72

(46 –180)

100

(46 – 273)

Age attaining weight

2.2 kg (d)

[mean(range)]

77

(36 – 99)

63

(47 – 80)

44

(35 – 61)

64

(35 – 99)

Baseline CharacteristicsBefore After p

Number 28 8 -

Mean birth weight (g) 1090 1135 0.645

Mean gestation age (wks) 27.8 28.5 0.288

Mean Hct at birth (%) 52.3 48.7 0.151

Ventilation days (d) 14.0 3.9 0.007

O2 days (d) 32.7 32.0 0.949

IVH ( G 3) (%) 3.6 0 0.778

BPD (%) 39.3 37.5 0.631

ROP ( G 3) (%) 10.7 0 0.459

Phlebotomy blood loss (ml) 55.9 32.8 0.002

Length of hospital stay (d) 99.6 84.4 0.463

Age attaining weight 2200 g (d) 63.1 59.6 0.629

Comparison of Transfusion Pattern Before & After New Guideline 2001

Mean no. of transfusion episodes/patient

Mean vol. of transfusion (ml/kg)/patient

Mean Donor no. /patient

Total No. Trans-fused

% Trans-fused

Day 14 Discharge Day 14 Discharge

Before 45 28 62.2 1.3 3 23.8 55.9 2.1

After 25 8 32.0 0.4 1.4 9.0 32.8 1.6

Reduction

- - 30.2 0.9 1.6 14.9 23.1 0.5

p 0.086 0.001 0.17 0.002 0.132

Compliance with New Transfusion GuidelinesBefore (1998 – 2000) After (2001)

No. of Transfusion Episodes

85 16

% Compliance with Guideline 2001

50.6 93.8

% Compliance with Guideline 1998

95.3 N/A

Ordering of Transfusion

% Pre MRCP 15.3 12.5

% Post MRCP 81.2 12.5

% FHKAM 3.5 75

% 2nd Round 83.5 81.3

Non-compliance Old guideline - 4 episodes

Pre-MRCP 1 Post-MRCP 1 FHKAM 2 2nd Round 3

New guideline - 1 episode FHKAM 1 2nd Round 1

Transfusion & Phlebotomy LossBW (g) 1000 1001 –

12501251 – 1500

NICHD 2001*(1251-1500)

Total

N 16 21 31 59 68

No. of Transfusion/patientMean (range)

4 (2 – 7) 3 (1-7) 2 (1-7) 1.1 1.7 3 (1-7)

Transfused % with 0 25 33.3 67.7 95 47.1

% with 1 0 28.6 19.4 3 17.6

% with 2 31.3 9.5 6.5 2 13.2

% with 3

43.8 28.6 6.5 0 22.1

Volume (ml/kg/patient)Mean (range)

80

(39 –177)

41

(15 – 95)

23

(14–53)

15 9 51

(14 –177)

No. of Donor/patient 3 (1- 4) 2 (1 –3) 2 (1 –4) - 2 (1 –4)

Phlebotomy loss Day 14

(ml/kg/patient)

39 23 19 26 15 28

Phlebotomy loss > Day 14

(ml/kg/patient)

38 20 11 25

Transfusion IndicationsBW (g) 1000 1001 –

1250

1251 –

1500

NICHD

2001

(1251-1500)

Number of Transfusion Episodes 50 37 14 59

Moderate ventilatory support % 32 13.5 14.3 24.2

Ventilatory respiratory support % 0 10.8 0 22.6

No ventilatory supp O2 or CPAP % 14 8.1 0 1.6

Increased O2 support % 2 8.1 0 14.5

Apnoea / Bradycardia % 16 13.5 21.4 6.5

Asymptomatic % 0 0 7.1 0

Old guideline – Hct < 0.40 % 20 5.4 21.4 -

Old guideline – Hct < 0.35 % 12 32.4 7.1 -

Old guideline – Hct < 0.27 % 0 5.4 21.4 -

Non – compliance % 4 2.7 7.1 29.0

Blood Investigations Performed

Before (1998-2000) After (2001)

BW (g) 1000 1000 1001 – 1500

1001 – 1500

1000 1000 1001 – 1500

1001 – 1500

N 10 10 18 18 2 2 6 6

Age (day) 14 > 14 14 > 14 14 > 14 14 > 14

CBP (n) 3.8 9.5 4.4 9.6 3.3 7 2.7 3.3

Hct (n) 14.6 9.1 7.4 2.6 9.3 7.7 5.3 3.2

RFT (n) 16.1 18.9 14.7 10.9 9 12.3 8.3 5.7

LFT (n) 2.7 9.3 2.7 6.4 2.7 7.7 1.9 4.1

ABG (n) 45.1 24.5 33.8 12.4 18.3 6.3 19.4 4.1

Blood Culture (n)

1.8 1.4 1.3 0.7 1.7 2.3 1.4 0.3

Phlebotomy loss (ml/kg)

41.5 41.1 22.9 18.2 23.6 21.5 16.8 11.9

Risk Factors for Total Volume of Transfusion

R2 = 0.870

Risk Factor Significance (p)

Total Phlebotomy blood loss < 0.001

Hct% at birth 0.023

Ventilation Days 0.025

Birth weight 0.370

IVH 0.712

BPD 0.62

O2 Days 0.944

Discussion Compliance

Generally is good Before

Old Guideline 95.3% New Guideline 50.6%

After Old Guideline NA New Guideline 93.8%

Discussion Reduction of RBC Transfusion

Before 62.2%

After 32%

Reduction of transfusion may due to More conservative new guideline Decreased phlebotomy blood loss Infants were less ill

RBC transfusion rate still higher if comparing with National Institute of Child Health and Human Development (NICHD) 2001

Discussion Reduction of Phlebotomy blood loss (ml/kg)

Before Day 14 Day 15 - Discharge 1000 41.5 41.1• 1001-1500 22.9 18.2

After 1000 23.6 25.1• 1001-1500 16.8 11.9

Comparable to NICHD 2001

Discussion Implementation of new guidelines can largely reduce the

number of blood transfusions in premature infants Reduction of phlebotomy loss contribute significantly to

reduction in transfusion requirements Morbidities (BPD, ROP), length of stay & age to attain

weight 2.2 kg (growth) were not significantly different with the implementation of new guideline

Although our phlebotomy blood loss is comparable to NICHD, our transfusion rate is still higher

The total volume of transfusion was largely accounted by phlebotomy blood loss & ventilation days

Discussion

Speculation – with modification of guideline, limiting blood loss & use of micro-methods (POCT), non-invasive laboratory monitoring, further more conservative transfusion approach may be adopted

? Use of Erythropoietin for preterm infants in PYNEH

Comparison of Transfusion Guidelines

Hct % PYNEH 1998

PYNEH 2001

NICHD 2001

Moderate ventilatory support 40 40 35

Ventilatory respiratory support 40 35 30

No ventilatory supp O2 or CPAP 35 30 25

Increased O2 support 35 30 25

Apnoea / Bradycardia 35 30 25

Asymptomatic 27 20 20

Thank you

Old guidelines 1998 Hct < 40% or Hb < 13 g/dl

if oxygen or ventilator dependent Hct < 35% or Hb < 10 g/dl

if symptomatic Hct < 27% or Hb < 8 g/dl

if asymtomatic Blood loss of > 10% of blood vo

lume

New guidelines 2001 Hct 40%, severe respiratory illness

Ventilator/CPAP, MAP >8 cmH2O

FiO2 > 50% Severe congenital heart disease with cya

nosis/heart failure Hct 35%

Ventilator/CPAP, MAP 6-8 cmH2O

FiO2 35-50%

Hct 30% Respiratory disease requiring FiO2 25-3

5% / nasal cannula O2 1/8-1/4 L/min CPAP/ IPPV, MAP <6 cmH2O Sustained tachycardia (>180/min) or tac

hypnoea (>80/min) for 24 hours Apnoea/bradycardia 10/24 hours or

2 requiring bag mask ventilation Cessation of wt gain x 4 days Undergoing major surgery

Hct 20% asymptomic Acute blood loss with shock

Risk Factors for Volume of Transfusion 14 days

Coefficientsa

29.815 57.393 .519 .608

.404 .750 .207 .538 .595

2.571E-03 .032 .025 .081 .936

-.424 .770 -.108 -.550 .587

8.118E-02 6.667 .003 .012 .990

8.099 13.470 .161 .601 .552

7.926E-03 .580 .005 .014 .989

-.130 .207 -.136 -.629 .534

(Constant)

GTOTAL/KG<=14

BW

HCT_BIRTH

IVH

BPD(36)

VENT_DAYS

O2_DAYS

Model1

B Std. Error

UnstandardizedCoefficients

Beta

Standardized

Coefficients

t Sig.

Dependent Variable: VOL_RBC<=14a.

Model Summary

.293a .086 -.143 26.5134Model1

R R SquareAdjustedR Square

Std. Errorof the

Estimate

Predictors: (Constant), O2_DAYS, HCT_BIRTH,GTOTAL/KG<=14, BPD(36), IVH, BW, VENT_DAYS

a.

Risk Factors for Total Volume of Transfusion

R2 = 0.870

Risk Factor Beta Significance

Total Phlebotomy blood loss 0.633 < 0.001

Hct% at birth - 0.219 0.023

Ventilation Days 0.263 0.025

Birth weight 0.891 0.370

IVH 0.292 0.712

BPD 0.079 0.62

O2 Days 0.608 0.944

Discussion Implementation of new guidelines can largely reduce the

number of blood transfusions in premature infants Reduction of phlebotomy loss contribute significantly to r

eduction in transfusion requirements Morbidities (CLD, ROP), length of stay & age to attain w

eight 2200 g (growth) were not significantly different with the implementation of new guideline

Although our phlebotomy blood loss is comparable to NICHD, our transfusion rate is still higher

The total volume of transfusion was largely accounted by phlebotomy blood loss & ventilation days

The inverse relationship between Hct% at birth and total volume of transfusion need further analysis