4th International Conference on PCRRT
Multiorgan failure, nutrition
and PCRRT
Bernhard Frey
Dep. of Intensive Care and Neonatology
University Children‘s Hospital Zürich
Structure of the talk
 A PCRRT in MOF:
Do not focus on technology only
 B The benefits of PCRRT in MOF
 C Some practical aspects of CVVH
A Do not focus on technology only
Cascade effects of medical technology
Deyo RA, Annu Rev Public Health, 2002
Critically ill child
Missing clinical skills
Fluid overload
Organ dysfunction (lungs, brain, heart)
CVVH
Side effects of CVVH
A Do not focus on technology only
Side effects of PCRRT (CVVH)
 Complications with vascular access
 Thrombosis
 Infection
 Air embolism
 Bleeding (anticoagulation)
 Increased lactate (Barenbrock M, Kidney, 2000)
 Filtration of essential molecules
 Systemic inflammatory response syndrome (SIRS)
A Do not focus on technology only
CVVH: Unintended consequencies?
 No prospective studies demonstrating benefit of
PCRRT (relating to relevant end-points)
 Renal replacement therapy independently associated
with increased mortality
(Metnitz P, Intensive Care Med, 2004)
 Experience with invasive technologies impacts on
outcome (Tilford JM, Pediatrics, 2000)
 Invasive technologies may be dangerous in
„threshold“ countries
CVVH: Unintended consequencies ?
Invasive therapies in low risk patients
70
Patients [%]
60
50
40
USA
Latin America
30
20
10
0
Central Catheters
Intubation
(Earle M, Crit Care Med, 1997)
A Do not focus on technology only
How to avoid PCRRT
 Avoid fluid overload
 Prevention of ARF in MOF
A Do not focus on technology only
Fluid overload in MOF
A Do not focus on technology only
Fluid overload in MOF
Stress, pain, nausea
Vasopressin
Morphine, barbiturates
Capillary leak
A Do not focus on technology only
Fluid overload in MOF
 Brain:
brain swelling
 Lungs: higher fluid balance
independent risk of mortality in ALI
(Sakr Y, Chest, 2005)
A Do not focus on technology only
Fluid overload: brain swelling
A Do not focus on technology only
Fluid overload: cerebral herniation
ICP
Intracranial volume
A Do not focus on technology only
Maintenance fluid
Holliday MA and Segar WE, Pediatrics, 1957:
Fluid requirements calculated by caloric expenditure
However: Sick children need much less fluids:
lower caloric intake
lower urinary excretion
decreased insensible losses
A Do not focus on technology only
How to order maintenance fluids
Analysis of:
 Total body water:
weight, edema/dehydration, fluid balance
 Blood volume:
microcirculation, diuresis, heart rate, (CVP, BP)
 Electrolytes:
Na
A Do not focus on technology only
Fluid requirements in ventilated
children
 < 10 kg
 > 10 kg
50 ml / kg / d
1200 ml / m2 / d
+ extra boluses (NaCl 0.9%) to increase cardiac output
Give enteral feeds instead of „free water drips“
A Do not focus on technology only
Volume to optimize preload
(Michard F, Crit Care, 2000)
A Do not focus on technology only
Prevention of ARF in MOF
 Optimize perfusion pressure and O2-delivery
O2-delivery = Cardiac Output x Hb x SaO2
 Avoid intraabdominal hypertension
A Do not focus on technology only
Measurement of
intraabdominal
pressure
PCRRT
B Benefits of PCRRT
The benefits of PCRRT in MOF
Indication
Fluid overload
ARF
Inadequate nutrition
B Benefits of PCRRT
The benefits of PCRRT in MOF
Commencing PCRRT early may be beneficial
(Goldstein S, Pediatrics, 2001)
B Benefits of PCRRT
Enteral nutrition in PICU
Early enteral nutrition:
 decreased length of hospital stay
 less infections
 improved wound healing
B Benefits of PCRRT
Enteral nutrition in PICU
(Rogers EJ, Nutrition, 2003)
B Benefits of PCRRT
Enteral nutrition in PICU
Energy supply is often inadequate
Reasons:
Measures:
Fluid restriction
Interruption of nutrition
start enteral feeds early
Give feeds, not water drips
early jejunal nutrition
favor enteral feeds
PCRRT
C Practical aspects
Practical aspects of PCRRT (CVVH)
Vascular access
Nutrition
Drug dosing
(Review: Norma Maxvold, Timothy Bunchman,
Crit Care Clin, 2003)
C Practical aspects
Vascular access
Neonate, 2.5 kg
MEDCOMP®
7 F, 10 cm
Filling volume: 0.8 + 0.8 ml
C Practical aspects
Vascular access
Neonate, 2.5 kg
MEDCOMP®
7 F, 10 cm
C Practical aspects
Nutrition in CVVH
The filter is highly permeable to water and other
small molecules:
amino acids
trace elements
water soluble vitamins
Double intake
C Practical aspects
Nutrition in CVVH
The net ultrafiltration rate has to be set to allow
adequate nutrition
< 1 year: EBM / infant formula + trace elements + vit.
> 1 year: Formula (Frebini®) + trace elements + vit.
(Whole protein formula)
C Practical aspects
Drug dosing:
Factors affecting drug elimination
Factor
Importance
Ultrafiltration rate
low
Molecular size
low
Drug-protein binding
high (sieving coeff.)
Volume of distribution
high
Physiological elemination
high
C Practical aspects
Drug dosing:
Drug specific numbers
 Sieving coefficient (Sc)
Sc = Cuf / Cp
(0 – 1)
Cuf: drug concentration in ultrafiltrate
Cp: drug concentration in plasma
 Volume of distribution (Vd)
C Practical aspects
Drug dosing: practical approach
Clinical signs of response or
intoxication
Drug concentration monitoring
(whenever possible)