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 APCRRT in MOF: Do not focus on technology only BThe benefits of PCRRT in MOF CSome 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 ? 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 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 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 kg50 ml / kg / d > 10 kg1200 ml / m 2 / 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 A Do not focus on technology only (Michard F, Crit Care, 2000)

Prevention of ARF in MOF Optimize perfusion pressure and O 2 -delivery O 2 -delivery = Cardiac Output x Hb x SaO 2 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 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: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 access C Practical aspects Neonate, 2.5 kg MEDCOMP® 7 F, 10 cm Filling volume: ml

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 elementsDouble 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 elimination FactorImportance Ultrafiltration ratelow Molecular sizelow Drug-protein bindinghigh (sieving coeff.) Volume of distributionhigh Physiological eleminationhigh C Practical aspects

Drug dosing: Drug specific numbers Sieving coefficient (Sc) Sc = C uf / C p (0 – 1) C uf : drug concentration in ultrafiltrate C p : 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) C Practical aspects