Fluids, Nutrition Flashcards
daily minimum urine output, sodium, potassium intake
Minimum UO = 0.5ml/kg/hr = ~30ml/hour
Na requirement = 1.5-2mmol/kg/day = 100mmol/day
K requirement = 1mmol/kg/day = 60mM/day
example fluid regimes (NBM)
3L dex-saline with 20mM K+ in each bag
• 1L normal saline + 2L dex with 20mM K+ in each bag
• Each bag over 8h = 125ml/h
sources of fluid losses post op
Vomiting and Diarrhoea NG tube Drains Fever Tachypnoea High-output stomas
central venous pressure depends on what?
preload
cardiac output
sensitive measure of volume status
Parkland burns + fluid formula
4 x SA% affected x weight kg
give half of the fluids calculated over first 8 hours
other half following 16
for use with Hartmann’s
assessing fluid status
Hx: balance chart, surgery, other losses, thirsty
• Impression: drowsy, alert
• Inspection: drips, drains, stomas, catheters, CVP
IV volume § CRT § HR § BP lying and standing § JVP • Tissue perfusion § Skin turgor § Oedema: ankle, pulmonary, ascites § Mucus membranes • End-organ § UO, ↑U+Cr § Consciousness § Lactate
U+Es
when should potassium replacement be avoided?
first 24 hours post op
PS use urine output to guide fluids, often only need 2L post op day 1 not 3L
what type of fluid do you avoid in renal / cardiac failure patients?
high sodium
use 5% dextrose
bowel obstructed patients and fluids
high loss of fluid and electrolyte
likely to need a lot more than normal
base off U+Es and urine
high output stoma
if 1L + a day, should be around 700ml
if too much, try loperamide/codeine (?)
reduced urine output post op
Post-renal § Commonest cause § Blocked / malsited catheter § Acute urinary retention • Pre-renal: hypovolaemia • Renal: NSAIDs, gentamicin • Anuria usually = blocked or malsited catheter • Oliguria usually = inadequate fluid replacement
checking for blocked catheter
try to flush 50ml saline and draw back (?)
complications of NG tube
nasal trauma
malposition
aspiration
4 complications of non-oral feeding
feed intolerance - diarrhoea
electrolyte imbalance
aspiration
refeeding syndrome
7 indications of parenteral nutrition
prolonged obstruction / ileus high output fistula short bowel syndrome severe Chron's severe malnutrition severe pancreatitis unable to swallow
delivery of parenteral nutrition
short term - central venous catheter
long term - PICC line
need dietician referral to manage
need regular monitoring of FBC UE LFT phosphate glucos
complications of parenteral feeding
Line-related § Pneumothorax / haemothorax § Cardiac arrhythmia § Line sepsis § Central venous thrombosis → PE or SVCO
• Feed-related § Villous atrophy of GIT § Electrolyte disturbances - Refeeding syndrome - Hypercapnoea from excessive CO2 production § Hyperglycaemia and reactive hypoglycaemia § Line sepsis: ↑ risk ¯c TPN § Vitamin and mineral deficiencies
describe refeeding syndrome
life-threatening derangement of metabloism on restarting oral intake after prolonged starvation
pathophysiology of refeeding syndrome
cells become deplete of phosphate, glucose, etc
sudden uptick in insulin on eating drives everything out of the blood into cells
hypophosphataemia is the key issue
also low potassium and magnesium
possible consequences of refeeding syndrome
→ hypophosphataemia § Rhabdomyolysis § Respiratory insufficiency § Arrhythmias § Shock § Seizures
