6. Fluid balance and nutrition Flashcards
Crystalloids
- Small enough to pass through vessel wall
- 0,9% NaCl, Ringer, hypertonic saline (3, 5, and 7.5 %)
Colloids
- Too large (>35kDa) to penetrate vessel wall - stays in vessel
- Albumin, starch, plasma, dextran
Extracellular fluid compartment components
1/3 intravascular, 2/3 interstitial
Total body water components
Intracellular fluid (40%) + extracellular fluid (20 %) (Blood+interst)
Normal osmolality
280 Osm
Fluid tonicity (isotonic, hypotonic etc)
Fluid osmolality compared to plasma
- Isotonic - same as plasma
- Hypotonic - less than plasma (fluid is absorbed faster)
Preload = ? (and how to increase/decrease)
Fluid volume
- Increase: packed RBCs, colloids, crystalloids
- Decrease: diuretics
Contractility - how to increase
- Dobutamine
- Dopamine
Afterload = ? (How to increase/decrease)
SVR: Systemic vascular resistance
- Increase/vasopress: Epinephrine, norepinephrine
- Decrease/vasodilate: Nitroprusside, nitrates
Starling forces in infusional therapy
- Hydrostatic and osmotic forces / semipermeable membranes
Osmotic vs oncotic pressure
Osmotic: independent of molecular size
Oncotic: osmotic pressure generated by macromolecules
Daily fluid loss in fever
1500-2000 ml
Daily fluid loss by tracheotomy
700 ml
Daily fluid loss in suction of bronchial secretion
500-1000 ml
Daily fluid loss in hyperventilation
500 - 2000 ml
Assessment of intravascular volume
Macrocirculation: preload, contractility, afterload
Monitor: Skin turgor, tongue, urine output
Swan-Ganz catheter
Pulmonary artery catheter - to detect HF or sepsis, monitor therapy and effect of drugs
PICCO plus
Arterial line with thermistor in end (detect temperature differences used to calculate CO) - used for hemodynamic monitoring (CO, pulse, preload etc)
Static hemodynamic parameters
- Central venous pressure (CVP)
- Pulmonary artery occlusion pressure (PAOP)
- Right ventricular EDV (end-diastolic volume)
- Left ventricular EDA (end-diastolic area)
- Global end-diastolic volume (GEDV)
- Intrathoracic blood volume (ITBV)
- Not suitable for assessing fluid responsiveness*
Dynamic hemodynamic parameters
- Systolic pressure variation (SPV)
- Stroke volume variation (SVV)
- Pulse pressure variation (PPV) - during pos. pressure ventilation (“PPV”)
SPV normal value
< 10 mmHg
PPV normal value
< 13 %
SVV normal value
< 10 %
Testing dynamic hemodynamic parameters
- S-G, PICCO, Echocardiography
- CO = SV * HR
- Inferior vena cava
- Passive leg raising test
György formula
For electrolyte disturbances
Na+ x K+ x OH-) / (Ca++ x Mg++ x H-
Treatment of hyperkalemia
- Calcium
- Glucose-insulin
- Beta-mimetics
- NaHCO3
- Hemodialysis
- Sodium polystyrene sulfonate resin (GI necrosis)
- FSD
- Treat underlying disorder
Treatment of hypokalemia
- Decrease potassium loss, find cause (e.g vomiting, diarrhea, diuretics, polyuria, laxatives)
- Increase K+ stores (KCl - except in DKA)
- Look for toxicity (ECG, ileus)
Ionized Ca++ levels
> 1,29 mmol/l
Corrected Ca2+ levels to serum albumin
> 2,6 mmol/l
MAH
Malignancy associated hypercalcemia - most frequent paraneoplastic SY, serious emergency
Hypercalcemia/MAH therapy
- Forced rehydration (NaCl 0,9% - 300-500 ml/hr)
- After! FSD (furosemide?) 20-40 mg iv (not thiazide!)
- Iv bisphosphonate (pamidronat, zoledronic acid)
- Calcitonin
- Hemodialysis
- Steroid: lymphomas
- RANKL AB (denosumab)
Hyponatremia
- E.g SIADH
- Higher urine osmolality (> 100 mOsm/l)
- Lower serum osmolality (< 280 mOsm/l)
- Serum Na+ < 135 mmol/l
- I.c edema
Jenny-spm: cramping/tremors are usually caused by hypo- or hyper-electrolytes?
Hypo (Ca, Na, Mg, K)
SIADH therapy
SeNa < 125 mmol/l
- Restriction of free water intake (500-100 ml/d)
- Demeclocyclin
SeNa < 115 mmol/l
- 3 % NaCl, then 0,9 % NaCl
- Furosemide
Vaptans: V2 antagonists
Limitations of increasing SeNa
Increase in SeNa must not exceed 0,5 mmol/l/h
If too fast correction - central pontine myelinolysis
Phases after operation
I. Catabolic phase (5-10 days)
II. Early anabolic phase (2-6 weeks)
III. Late anabolic phase (2-6 months)
OFNoSH
Organisation of Food and Nutritional Support in Hospitals
Mild malnutrition weight loss
< 10 % weight loss in last 6 months (important!)
Moderate malnutrition weight loss
10 - 19 % weight loss in last 6 months (important!)
Severe malnutrition weight loss
> 20 % weight loss in last 6 months (important!)
Lab parameters to look at in malnutrition
- Serum albumin
- Serum transferrin
- Serum prealbumin
REE: Resting energy expenditure
REE = BEE x stress factor
TEE: Total energy expenditure (kcal/day)
TEE = REE x activity factor
Stress factors influencing REE
- Major surgery
- Polytrauma
- Burns (Highest influence - 2,20!!)
- Sepsis
- COPD
Activity factors influencing TEE
- Sedated-ventilated patient (lower activity - 1-1,2)
- Ventilated (lower activity - 1,2)
- Ward patient (1,3-1,7)
Risk of overfeeding
- Fatty liver
- Hyperglycemia
- Leukocyte dysfunction
- Hyperosmolarity
- CO2 production increase
- Respiratory insufficiency
Carbohydrates
60-80 % of nutrition
Rate-limiting point in nutrition in sepsis
Pyruvate dehydrogenase - has decreased activity in sepsis, and extra pyruvate is the substrate of lactic acid production in hypoxia
Max glucose intake dose in ICU pts
5 g/kg/d
Daily minimum of carbohydrates
150 g
Lipids
20-40 % of nutrition
Max dose of lipid intake per day
1 - 1,5 g/kg/d
Overdose of lipids
- Hypertriglyceridemia
- Fatty liver
- Leukocyte R sensitivity lowered
- AA (prostaglandin, TXA, leukotriene precursor)
For which pts are lipids not recommended
- Hypertriglyceridemia
- Severe metabolic acidosis, hypoxia
- DKA
- Acute necrotizing pancreatitis
- Serious lung disease
- Trauma (infection rate, resp. insuff)
Protein daily intake
1 - 1,4 g/kg/d (50% should be branched chain)
Contraindication of protein intake
Congenital metabolic disorder
General nutrition guide
- Prefer enteral nutrition
- Enteral nutrition (NG tube) should be started within 24 hrs
- If EN is impossible: prokinetics, small bowel nutrition or parenteral nutrition
Problems with enteral nutrition
- Gastric residual volume
- Gastric bacterial colonization
- Aspiration pneumonia
- Enteral ischemia
Problems with parenteral nutrition
- Bowel mucosal atrophy
- Overfeeding
- Hyperglycemia
- Infection risk
- Permanent line needed
- More expensive (?)
General enteral nutrition guide
- Polymer formula
- Upper body elevated 45°
- Start within 24-48 hrs if no contraind
- Begin with 25 ml/h and increase by 25 ml/h every 4 hrs
Enteral nutrition consideerations
- Lack of bowel sounds: does not (!) mean you have to reduce EN
- GRV: gastric residual volume must be considered - try metoclopramide if too high (> 250 ml)
- Single vomiting and diarrhea - not (!) contraindications
Indications for parenteral nutrition
- EN impossible for > 3 days
- Malnutrition: early initialization required
- EN is not possible/recommended: perioperative, pancreatitis, GI obstruction, malabsorption, short bowel syndrome
- Patient doesn´t want to have EN (vomiting , lack of appatite)
- If no justified indications - PN should not be used!!
Pharmanutrition
Some nutrient that also has biological effects (antioxidants, PG, NO, vitamins)
When is micronutrient substitution required?
- When patient have less than 1000 ml enteral nutrient intake
- When using parenteral nutrition as it only contains macronutrients (sånn som jeg forsto sliden)
Malabsorption - vitamins affected
A, D, E, K
Which vitamin often lacks from vitamin products and why?
Vitamin K - anticoagulation potential
Most important trace elements
Zinc and Selenium
- Most products do not contain iron due to risk of anaphylaxis
Zinc deficiency
- Dermatitis
- Alopecia
- Decreased healing
- Gonadal atrophy
- Immune system decrease
Selenium
- Cardiomyopathy
- Myositis
- Arthritis
- Hair and nail disorders
ATP and nutrition
Tissue oxygenation will not give ATP on its own unless supported by adequate nutrition
Clinical nutrition consists of
- Screening
- Assessment
- Plan
- Documentation
- Reassessment
