Nutrition Support of the Critically Ill Patient with Organ Failure

Respiratory Failure Function of lungs: Move oxygen from air to venous blood and move carbon dioxide (CO2) out Function of lungs: Move oxygen from air to venous blood and move carbon dioxide (CO2) out Important functional components of lung: Important functional components of lung: Drive mechanism Drive mechanism Muscles of respiration Muscles of respiration Alveoli Alveoli Source: Hasse J. Nutrition and Organ Failure. In DNS. Sharpening Your Skills as a Nutrition Support Dietitian, 2003, p. 227

Acute Respiratory Failure Type 1: hypoxic respiratory failure. Type 1: hypoxic respiratory failure. Low PaO2 with low to normal PaCO2 Low PaO2 with low to normal PaCO2 (PaO2/PaCO2 = partial pressure exerted by O2/CO2 dissolved in arterial plasma) (PaO2/PaCO2 = partial pressure exerted by O2/CO2 dissolved in arterial plasma) Type 2: hypercapneic-hypoxic respiratory failure. Type 2: hypercapneic-hypoxic respiratory failure. Low PaO2 with increased PaCO2 Low PaO2 with increased PaCO2

Acute Respiratory Distress Syndrome (ARDS) PaO2:FiO2 ratio ≤ 200 PaO2:FiO2 ratio ≤ 200 (FiO2 = fraction of inspired oxygen, the % concentration of oxygen entering the lungs, ventilator or a blood oxygenator) (FiO2 = fraction of inspired oxygen, the % concentration of oxygen entering the lungs, ventilator or a blood oxygenator) Bilateral pulmonary infiltrates seen on X-ray Bilateral pulmonary infiltrates seen on X-ray PAW ≤ 15) mm/Hg PAW ≤ 15) mm/Hg PAW = pulmonary artery wedge pressure; normal is ≤ 12 mm/Hg PAW = pulmonary artery wedge pressure; normal is ≤ 12 mm/Hg

Chronic Respiratory Failure Asthma Asthma COPD COPD Bronchiectasis Bronchiectasis Cystic Fibrosis Cystic Fibrosis Infiltrative disease of the lung Infiltrative disease of the lung Pulmonary hypertension Pulmonary hypertension

Treatment Goals for Respiratory Failure Treat underlying condition Treat underlying condition Support physiologic function Support physiologic function Maintain tissue oxygen delivery Maintain tissue oxygen delivery Minimize pulmonary edema Minimize pulmonary edema Give nutrition support Give nutrition support Prevent/manage infection Prevent/manage infection Source: Hasse J. Nutrition and Organ Failure. In DNS. Sharpening Your Skills as a Nutrition Support Dietitian, 2003, p. 227

Mechanical Ventilation Modes Assist control (AC) Assist control (AC) Intermittent mandatory ventilation Intermittent mandatory ventilation Synchronized intermittent mandatory ventilation Synchronized intermittent mandatory ventilation

Mechanical Ventilation Settings CPAP: continuous positive airway pressure CPAP: continuous positive airway pressure PEEP: positive end-expiratory pressure PEEP: positive end-expiratory pressure PEEP: A method of ventilation in which airway pressure is maintained above atmospheric pressure at the end of exhalation by means of a mechanical impedance, usually a valve, within the circuit. Purpose is to increase volume of gas remaining in lungs after expiration to decrease shunting of blood through the lungs and improve gas exchange. PEEP is done in ARDS (acute respiratory failure syndrome) to allow reduction in the level of oxygen being given PEEP: A method of ventilation in which airway pressure is maintained above atmospheric pressure at the end of exhalation by means of a mechanical impedance, usually a valve, within the circuit. Purpose is to increase volume of gas remaining in lungs after expiration to decrease shunting of blood through the lungs and improve gas exchange. PEEP is done in ARDS (acute respiratory failure syndrome) to allow reduction in the level of oxygen being givengas exchangeARDSgas exchangeARDS PSV: pressure support ventilation PSV: pressure support ventilation HFV: high frequency ventilation HFV: high frequency ventilation

Nutrient Requirements in Pulmonary Failure Calories: don’t overfeed when weaning to prevent increased CO2 production Calories: don’t overfeed when weaning to prevent increased CO2 production Provide kcal/kg or resting energy expenditure Provide kcal/kg or resting energy expenditure Protein: g/kg Protein: g/kg Amino acids may increase ventilation, increase O2 consumption and ventilatory response to hypoxia and hypercapnea Amino acids may increase ventilation, increase O2 consumption and ventilatory response to hypoxia and hypercapnea Carbohydrate: <5,g/kg/min Carbohydrate: <5,g/kg/min Overall calories more important than percent CHO Overall calories more important than percent CHO Fat: N3 FA may be anti-inflammatory and alter immune status in sepsis/ARDS Fat: N3 FA may be anti-inflammatory and alter immune status in sepsis/ARDS

Respiratory Quotient (RQ) RQ is the ratio of carbon dioxide produced to oxygen consumed; is an indicator of fuel utilization RQ is the ratio of carbon dioxide produced to oxygen consumed; is an indicator of fuel utilization Normal (physiologic) range is 0.5 to 1.5 Normal (physiologic) range is 0.5 to 1.5 High RQ in a ventilator patient may make it difficult to wean the patient from the respirator High RQ in a ventilator patient may make it difficult to wean the patient from the respirator

Respiratory Quotient Values for Various Fuel Substrates Fat0.7 Protein0.8 Carbohydrate1.0 Mixed Diet ~0.85 Alcohol0.67 Underfed<0.8 Adequately fed Overfed>1.0

Treatment Goals for Liver Failure Identify and treat cause of liver failure (if reversible) Identify and treat cause of liver failure (if reversible) Control problems associated with liver failure Control problems associated with liver failure Give nutrition support Give nutrition support Prevent/treat infection Prevent/treat infection

Nutrient Requirements for Liver Failure Calories: caloric requirements affected by acuteness of disease, seriousness of injury, absorption, other organ failure, sepsis; kcals/kg or REE Calories: caloric requirements affected by acuteness of disease, seriousness of injury, absorption, other organ failure, sepsis; kcals/kg or REE Protein: well nourished/low stress:.8 g/kg; malnourished/with metabolic stress: up to 1.5 g/kg Protein: well nourished/low stress:.8 g/kg; malnourished/with metabolic stress: up to 1.5 g/kg CHO: ~70% non-protein calories; in acute failure, may need continuous glucose infusion CHO: ~70% non-protein calories; in acute failure, may need continuous glucose infusion Chronic: may have diabetes/hypoglycemia requiring controlled CHO and insulin; in septic pts hypoglycemia occurs in 50% of cirrhotics Chronic: may have diabetes/hypoglycemia requiring controlled CHO and insulin; in septic pts hypoglycemia occurs in 50% of cirrhotics FAT: 30% non-protein calories; MCT may be helpful with LCT malabsorption FAT: 30% non-protein calories; MCT may be helpful with LCT malabsorption

Fat Soluble Vitamins: Causes of Deficiencies in Liver Failure Vitamin A: steatorrhea, neomycin, cholestyramine, alcohol Vitamin A: steatorrhea, neomycin, cholestyramine, alcohol Vitamin D: steatorrhea, glucocorticoids, cholestyramine Vitamin D: steatorrhea, glucocorticoids, cholestyramine Vitamin E: steaorrhea, cholestyramine Vitamin E: steaorrhea, cholestyramine Vitamin K: steatorrhea, antibiotics, cholestyramine Vitamin K: steatorrhea, antibiotics, cholestyramine Source: Hasse J. Nutrition and Organ Failure. In DNS. Sharpening Your Skills as a Nutrition Support Dietitian, 2003, p. 227

Water Soluble Vitamins: Causes of Deficiencies in Liver Failure B6: alcoholism B6: alcoholism B12: cannot exclude deficiency during active liver inflammation, fatty liver, carcinoma; causes alcoholism, cholestyramine B12: cannot exclude deficiency during active liver inflammation, fatty liver, carcinoma; causes alcoholism, cholestyramine Niacin: alcoholism Niacin: alcoholism Thiamin: alcoholism Thiamin: alcoholism Folate:alcoholism Folate:alcoholism Source: Hasse J. Nutrition and Organ Failure. In DNS. Sharpening Your Skills as a Nutrition Support Dietitian, 2003, p. 227

Minerals: Causes of Deficiencies in Liver Failure Zinc: diarrhea, diuretics, alcoholism Zinc: diarrhea, diuretics, alcoholism Magnesium: alcoholism, diuretics Magnesium: alcoholism, diuretics Iron: chronic bleeding (hemochromatosis causes overload) Iron: chronic bleeding (hemochromatosis causes overload) Potassium: affected by diuretics, anabolism, insulin use, renal function Potassium: affected by diuretics, anabolism, insulin use, renal function Phosphorus: affected by alcoholism, anabolism, renal function Phosphorus: affected by alcoholism, anabolism, renal function

Renal Failure: Functions of Kidney Excrete waste Excrete waste Electrolyte balance Electrolyte balance Hormonal regulation Hormonal regulation Blood pressure regulation Blood pressure regulation Glucose homeostatis Glucose homeostatis

Causes of Acute Renal Failure Acute Tubular Necrosis: nephrotoxins (radiologic contrasts) aminoglycosides, NSAIDS, cisplatin, ethylene glycol, ACE inhibitors. Presents with ↓ UO, ↑ BUN, ↑ Creatinine, ↓ HCO3, ↑ or normal K+, ↑ phos Acute Tubular Necrosis: nephrotoxins (radiologic contrasts) aminoglycosides, NSAIDS, cisplatin, ethylene glycol, ACE inhibitors. Presents with ↓ UO, ↑ BUN, ↑ Creatinine, ↓ HCO3, ↑ or normal K+, ↑ phos Oliguric phase persists ~1-2 weeks followed by diuretic phase Oliguric phase persists ~1-2 weeks followed by diuretic phase

Causes of Acute Renal Failure Prerenal azotemia: most common cause of acute azotemia, secondary to volume depletion Prerenal azotemia: most common cause of acute azotemia, secondary to volume depletion Acute interstitial nephritis Acute interstitial nephritis Atheromatous emboli Atheromatous emboli Ureteral obstruction Ureteral obstruction Intrarenal obstruction Intrarenal obstruction

Treatment Goals for Acute Renal Failure Correct electrolytes Correct electrolytes Control acidosis Control acidosis Treat significant hyperphosphatemia Treat significant hyperphosphatemia Treat symptomatic anemia Treat symptomatic anemia Initiate dialysis for hyperkalemia or acidosis not controlled, fluid overload, ↑ in BUN>20 mg/dl/24 hours or BUN>100 mg/dl Initiate dialysis for hyperkalemia or acidosis not controlled, fluid overload, ↑ in BUN>20 mg/dl/24 hours or BUN>100 mg/dl Evaluate drugs for renal effect Evaluate drugs for renal effect Avoid/treat infection Avoid/treat infection

Continuous Renal Replacement Therapy (CRRT) Blood filtered continuously by semi-permeable membrane Blood filtered continuously by semi-permeable membrane Arteriovenous uses patient’s own blood pressure Arteriovenous uses patient’s own blood pressure Venovenous: pump-driven Venovenous: pump-driven Lower extracorporeal blood volume (compared to HD) so better tolerated by hemodynamically unstable patients Lower extracorporeal blood volume (compared to HD) so better tolerated by hemodynamically unstable patients Types: hemofiltration (AVH, CAVH, SCUF), continuous hemodialysis (CAVHD, CVVHD) and continuous hemodiafiltration (CAVHDF or CVVHDF) Types: hemofiltration (AVH, CAVH, SCUF), continuous hemodialysis (CAVHD, CVVHD) and continuous hemodiafiltration (CAVHDF or CVVHDF)

Nutrition Implications of ARF ARF causes anorexia, nausea, vomiting, bleeding ARF causes anorexia, nausea, vomiting, bleeding ARF causes rapid nitrogen loss and lean body mass loss (hypercatabolism) ARF causes rapid nitrogen loss and lean body mass loss (hypercatabolism) ARF causes ↑ gluconeogenesis with insulin resistance ARF causes ↑ gluconeogenesis with insulin resistance Dialysis causes loss of amino acids and protein Dialysis causes loss of amino acids and protein Uremia toxins cause impaired glucose utilization and protein synthesis Uremia toxins cause impaired glucose utilization and protein synthesis

Nutrient Requirements in ARF Calories: kcals/kg dry weight or REE Calories: kcals/kg dry weight or REE Protein: about g amino acids lost per day with CRRT Protein: about g amino acids lost per day with CRRT ARF w/o HD (expected to resolve within a few days):.6-1 g pro/kg ARF w/o HD (expected to resolve within a few days):.6-1 g pro/kg Acute HD: g/kg; acute PD: g/kg; CRRT: g/kg Acute HD: g/kg; acute PD: g/kg; CRRT: g/kg CHO: ~60% total calories; limit to 5 mg/kg/min; peripheral insulin resistance may limit CHO CHO: ~60% total calories; limit to 5 mg/kg/min; peripheral insulin resistance may limit CHO In CWHD(F) watch for CHO in dialysate or replacement fluids In CWHD(F) watch for CHO in dialysate or replacement fluids Fat: 20-35% of total calories; lipid clearance may be impaired Fat: 20-35% of total calories; lipid clearance may be impaired

Vitamins in ARF Vitamin A: elevated vitamin A levels are known to occur with RF Vitamin A: elevated vitamin A levels are known to occur with RF Vitamin B – prevent B6 deficiency by giving 10 mg pyridoxine hydrochloride/day Vitamin B – prevent B6 deficiency by giving 10 mg pyridoxine hydrochloride/day Folate and B6: supplement when homocysteine levels are high Folate and B6: supplement when homocysteine levels are high Vitamin C: <200 mg/day to prevent ↑ oxalate Vitamin C: <200 mg/day to prevent ↑ oxalate Activated vitamin D Activated vitamin D Vitamin K: give Vitamin K especially to pts on antibiotics that suppress gut production of K Vitamin K: give Vitamin K especially to pts on antibiotics that suppress gut production of K

Minerals in RF ↑ potassium, magnesium, and phos occur often due to ↓ renal clearance and ↑ protein catabolism ↑ potassium, magnesium, and phos occur often due to ↓ renal clearance and ↑ protein catabolism ↓ potassium, mg and phos can occur with refeeding ↓ potassium, mg and phos can occur with refeeding CRRT pts can have ↓ K+, phos CRRT pts can have ↓ K+, phos Mg deficiency can cause K+ deficiency resistant to supplementation Mg deficiency can cause K+ deficiency resistant to supplementation Vitamin C, copper, chromium lost with CVVH Vitamin C, copper, chromium lost with CVVH

Fluid in ARF Depends on residual renal function, fluid and sodium status, other losses Depends on residual renal function, fluid and sodium status, other losses Usually 500 mL/day + urine output Usually 500 mL/day + urine output Fluid replacement needs can be ↑ with CRRT Fluid replacement needs can be ↑ with CRRT

Multiple Organ Failure: SIRS Site of infection established and at least two of the following are present Site of infection established and at least two of the following are present —Body temperature >38° C or 38° C or <36° C —Heart rate >90 beats/minute —Respiratory rate >20 breaths/min (tachypnea) —PaCO 2 <32 mm Hg (hyperventilation) —PaCO 2 <32 mm Hg (hyperventilation) —WBC count >12,000/mm 3 or 12,000/mm 3 or <4000/mm 3 —Bandemia: presence of >10% bands (immature neutrophils) in the absence of chemotherapy-induced neutropenia and leukopenia

Nutrition/Metabolism Considerations Determine priorities for medical and nutrition therapy Determine priorities for medical and nutrition therapy 3-5 times higher catabolism 3-5 times higher catabolism Increased skeletal muscle proteolysis Increased skeletal muscle proteolysis Shift of amino acids from periphery to viscera for gluconeogenesis Shift of amino acids from periphery to viscera for gluconeogenesis

Nutrient Needs in MODS Calories: 35 kcal/kg or REE Calories: 35 kcal/kg or REE Protein: up to g/kg Protein: up to g/kg Fat: 30% nonprotein calories; ↑ MCT if bile salt deficient; N3 vs N6 Fat: 30% nonprotein calories; ↑ MCT if bile salt deficient; N3 vs N6 Micronutrients: evaluate individually Micronutrients: evaluate individually Fluid: based on fluid status Fluid: based on fluid status Source: Hasse J. Nutrition and Organ Failure. In DNS. Sharpening Your Skills as a Nutrition Support Dietitian, 2003

Feeding Route EN usually preferred over PN; PN may worsen liver function EN usually preferred over PN; PN may worsen liver function Intubation does not preclude aspiration Intubation does not preclude aspiration EN not contraindicated with varices EN not contraindicated with varices Patients with CRF often may have gastroparesis; may need motility agent Patients with CRF often may have gastroparesis; may need motility agent Source: Hasse J. Nutrition and Organ Failure. In DNS. Sharpening Your Skills as a Nutrition Support Dietitian, 2003

Formula Selection Concentrated formulas may be helpful with fluid restriction Concentrated formulas may be helpful with fluid restriction Formulas restricted in phos and potassium may be helpful in pts with high phos and K+ Formulas restricted in phos and potassium may be helpful in pts with high phos and K+ Immune-enhancing formulas (controversial) Immune-enhancing formulas (controversial) Source: Hasse J. Nutrition and Organ Failure. In DNS. Sharpening Your Skills as a Nutrition Support Dietitian, 2003

Conclusion Critically ill patients with organ failure present special challenges to the nutrition care professional and medical team Critically ill patients with organ failure present special challenges to the nutrition care professional and medical team Medical and nutritional goals must be prioritized in these complex patients Medical and nutritional goals must be prioritized in these complex patients