Paediatric Brain Trauma Management:
Moving towards evidence based
practice
Dr. T. Y. M. Lo
Consultant Paediatric Intensivist
Royal Hospital for Sick Children, Edinburgh
Demographics
Head trauma
– commonest cause for A&E attendants aged < 15 yrs old
Brain trauma
– Commonest cause of death
– Commonest cause of newly acquired disability (> 100
per 100 000 population)
• Significant problem with memory & attention deficits
• Learning difficulties
• Disruptive behaviours / lack of inhibition (Frontal lobe
syndrome)
Outcome Determinants
Brain Trauma
Primary Brain Injury
Secondary Brain Insult
Outcome
Secondary Insult
Cerebral ischaemia / Inflammation / Energy failure
• Hypoxia
• Hypotension
• Low cerebral perfusion pressure
• Raised ICP
• Pyrexia
• Seizures
• Hypoglycaemia / hyperglycaemia
• Electrolytes abnormalities
Which Physiological Abnormalities
Best Predict Outcome?
Best Treatment Option - Prevention of
secondary physiological insults
Total duration of low CPP best predict outcome (p < 0.004).
(Jones et al. British Journal Neurosurgery. 2003. 17:29-39)
Brain Trauma Treatment Goals
Adults
• Treat if ICP > 20 mmHg
• Keep CPP > 70 mmHg & avoid < 50 mmHg
J Neurotrauma, May 2007
(Thresholds not validated)
Brain Trauma Treatment Goals
Children
• Treatment goals vary significntly between units
Tilford et al. CCM, 2001.
• Treat if ICP > 20 mmHg
• CPP 40 - 65 mmHg, avoid < 40 mmHg
Pediatric Critical Care Medicine, 2003.
(Thresholds not validated)
Developing Age Specific Treatment Goals
Limiting Factors
• Mostly adult studies
• Methodology to quantify ICP & CPP insult limited
to single dimension
• Intracranial physiology changes with age
(CPP = MAP - ICP)
– Good age specific MAP data
– Very little age specific ICP data
– No age-specific CPP data
Hypothesized Age-specific Minimum CPP
Levels
70
(mmHg)
60
50
40
CPP
30
20
Jones et al. Br J Neurosurg. 2003
10
•CPP =
5th percentile MAP level
0
0
5
10
15
20
Age
(yrs)
Edinburgh - Newcastle TBI Study
• Prospective
observational study
• 79 children
– 52 boys, 27 girls
• Two regional
centres
CPP Insult Quantification
Cumulative pressure-time index (PTI)

PTI   CPPthreshold CPP
 t
sampleinterval
(Chambers, Jones, Lo et al. JNNP 2006)
PTI & Outcome
Outcome
Mean PTI Value
Independent
(GOS 4 & 5)
3228
(95% CI 1557, 4898)
Poor
(GOS 1 - 3)
32713
(95% CI 16168, 49258)
Significant difference between the PTI area
product and outcome (p<0.001)
Chambers, Jones, Lo et al. JNNP 2006
ROC Curve for Different CPP Thresholds
Sensitivity
1.0
0.8
0.6
AUC
Threshold 0.890
Less 10% 0.883
Less 20% 0.886
0.4
0.2
1-specificity
Age-related CPP Insult Thresholds
Aged 2 - 6 yrs - 48 mmHg
Aged 7 - 10 yrs - 54 mmHg
(Chambers, Jones, Lo et al JNNP 2006)
Age 11 - 16 yrs - 56 mmHg
CPP Treatment Thresholds
Treatment
Thresholds
Critical
Insult
Thresholds
Aged
2 – 6 yrs
Aged
7 – 10 yrs
Aged
11 – 16 yrs
55 mmHg
60 mmHg
65 mmHg
48 mmHg
54 mmHg
58 mmHg
All individual characteristics of CPP
affect brain trauma outcome
Lo et al, PCCM 2011 (Suppl)
Clinical Importance
To improve childhood brain trauma outcome,
AVOID ANY significant reduction in CPP below
the age-related insult threshold, of any duration
CPP Management
in the Pre-ICU Setting
• Should we be thinking about optimizing CPP in
the pre-ICU setting?
• Do you have targets for MAP (CPP)?
• What about age-related targets for MAP
(CPP)?
Opening ICP + CPP in
Childhood Brain Trauma
N = 48 children with TBI
• Opening ICP > 20 mmHg = 18 (37.5%)
• Opening ICP > 15 mmHg = 26 (54%)
• Opening ICP > age-related norms = 33 (68.8%)
• Opening CPP below treatment thresholds = 19
(39.6%)
CPP Targets Pre-ICU
• Avoid reduction below age-related CPP insult
thresholds
• Assume ICP 20 mmHg
• Keep MAP at least
– Aged 2 – 6 yrs > 75 mmHg
– Aged 7 – 10 yrs > 80 mmHg
– Aged 11 – 16 yrs > 85 mmHg
Brain Trauma Inter-hospital Transfers
• Who should do it?
– Primary hospital team vs Regional Retrieval
Service
• What’s the ‘Power-that-be’ (NICE; SIGN;
RCPCH) recommendation??
• Can it be done???
Brain Trauma Primary Team Transfers
• Median distance from RHSC 35.2 miles (17.8 - 174.3
miles)
• Median stabilization time (Ts) 216.0 mins (60 - 390.0
mins)
• Median referral time (Tr) 62.0 mins (40.0 - 148.0
mins)
• Median journey time 56.0 mins (15.0 - 265.0 mins)
• Median time between injury to reaching neurosurgical centre 5.3 hrs (1.8 - 9.8 hrs)
(Dieppe, Lo et al. ICM 2010)
Edinburgh Retrieval Team Standards
• Median distance between RHSC and refering hospital
35.2 miles (7.5 - 211.5 miles)
• Median mobilization time (Tm) 60.0 mins (13.0 285.0 mins)
• Median ambulance response time 15.0 mins (5.0 135.0 mins)
• Median travel time 58.0 mins (17.0 - 240.0 mins)
• Median travel time per mile (Tt) 1.4 mins / mile (0.1 14.0 mins / mile)
(Dieppe, Lo et al. ICM 2010)
Theoretical Maximum Distance (D)
Brain Trauma Retrieval = 67 miles
D = (Ts - Tr - Tm) / Tt
(Dieppe, Lo et al. ICM 2010)
Summary
• CPP insult is the most significant outcome
predictor in childhood brain trauma.
• To improve childhood brain trauma outcome,
AVOID ANY reduction in CPP below age-related
insult thresholds of any duration.
• Think about maintaining an adequate MAP (CPP)
with an assumption of ICP > 20 mmHg in the preICU setting (including during inter-hospital
transfer).