multiorgan failure, nutrition and pcrrt bernhard frey dep. of intensive care and neonatology...
TRANSCRIPT
Multiorgan failure, nutrition and PCRRT
Bernhard Frey
Dep. of Intensive Care and Neonatology
University Children‘s Hospital Zürich
4th International Conference on PCRRT
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
Cascade effects of medical technology
Critically ill child
Missing clinical skills
Fluid overload
Organ dysfunction (lungs, brain, heart)
CVVH
Side effects of CVVH
Deyo RA, Annu Rev Public Health, 2002
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
A Do not focus on technology only
CVVH: Unintended consequencies ?
0
10
20
30
40
50
60
70
Central Catheters Intubation
Pat
ien
ts [
%]
USA
Latin America
Invasive therapies in low risk patients
(Earle M, Crit Care Med, 1997)
How to avoid PCRRT
Avoid fluid overload
Prevention of ARF in MOF
A Do not focus on technology only
Fluid overload in MOFA 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
A Do not focus on technology only
ICP
Intracranial volume
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 Total body water:
weight, edema/dehydration, fluid balance
Blood volume:
microcirculation, diuresis, heart rate, (CVP, BP)
Electrolytes:
Na
Analysis of:
A Do not focus on technology only
Fluid requirements in ventilated children < 10 kg 50 ml / kg / d > 10 kg 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 preloadA Do not focus on technology only
(Michard F, Crit Care, 2000)
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
A Do not focus on technology only
PCRRT
The benefits of PCRRT in MOFIndication
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: Fluid restriction
Interruption of nutrition
Measures: start enteral feeds early
Give feeds, not water drips
early jejunal nutrition
favor enteral feeds
PCRRT
B Benefits of PCRRT
Practical aspects of PCRRT (CVVH)Vascular access
Nutrition
Drug dosing
(Review: Norma Maxvold, Timothy Bunchman, Crit Care Clin, 2003)
C Practical aspects
Vascular accessC Practical aspects
Neonate, 2.5 kg
MEDCOMP®
7 F, 10 cm
Filling volume: 0.8 + 0.8 ml
Vascular accessNeonate, 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 Double intake
water soluble vitamins
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 eliminationFactor 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 approachClinical signs of response or
intoxication
Drug concentration monitoring (whenever possible)
C Practical aspects