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Flashcards in IV fluids and Nutrition Deck (74)
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1
Q

why is Hartmann’s solution preferred over 0.9% NaCl in surgery in relation to Cl- concentration?

A

concentration less in Hartmann’s (111mmol/L), and too much Cl- can lead to a hyperchloraemic metabolic acidosis developing in which increase in Cl- reduces HCO3-.
also, too much Cl- can cause vasoconstriction.

2
Q

indications a ptnt may need urgent fluid resuscitation?

A
clinical assess: dry mouth, loss of skin turgor, sunken eyes, CRT>2s, cold peripheries
RR>20 breaths/min
HR>90beats/min
systolic BP less than 100mmHg
an early warning score of 5 or more
3
Q

normal daily water requirement in maintenance fluids?

A

25-30ml/kg/day

4
Q

normal Na+, Cl- and K+ requirement in maintenance fluids?

A

1mmol/kg/day

5
Q

normal glucose requirement in maintenance fluids?

A

50-100g/day glucose

6
Q

the 5 Rs of assessment and re-evaluation of a pt’s fluid and electrolyte needs?

A
resuscitation
replacement
routine maintenance
redistribution
reassessment
7
Q

why is it so important to feed a bariatric ill pt on a ward as much or more than a normal well individual?

A

eventhough pt is overweight, he will not be mobilising his fat stores to provide energy. disease will mean his BMR is high, his hormones will be raised, so his hormone sensitive lipase will be low and once glucose consumed from blood and from glycogenolysis, muscle breakdown occurs to produce glucose.
Muscle Loss will provide significant immobility for pt, increasing bed stay, and reducing prognosis and recovery rate, Susceptible to LRTI with resp. muscle wkness.

8
Q

best simple assessment of adequate nutrition in hosp in-pt?

A

BMI

serum albumin= good predictor of surgical outcome but correlates poorly with overall nutritional status as influenced by injury or illness

9
Q

-ves of parenteral nutrition?

A

line sepsis
line thrombosis
metabolic imbalance e.g. acid-base disturbance, cholestasis- raised LFTs and ALP
some nutrients not available via this route e.g. short chain FA for colonic mucosa provided by bacterial degradation of fibre or carbohydrate.
intestinal mucosal atrophy?
mechanical injury e.g. pneumothorax

10
Q

kcal in 1g of protein?

A

4

11
Q

kcal in 1g of carbohydrate?

A

4

12
Q

kcal in 1g of fat?

A

9

13
Q

indications for parenteral feeding?

A
inadequate length of absorptive intestine
intestinal obstruction
severe mucositis
severe sepsis producing ileus
high-ouput entero-cutaneous fistula
chronic intestinal pseudo-obstruction
14
Q

in which pts might nasojejunal feeding be useful?

A

gastroparesis

pancreatitis

15
Q

why is continuous drip feeding better than bolus?

A

bolus can lead to reflux and diarrhoea

gen. start at 30ml/hr

16
Q

common indication for PEG?

A

inability to eat satisfactorily 2 wks post stroke

17
Q

how is a PICC inserted?

A

via basilic vein at antecubital fossa, avoiding cephalic as it joins the axillary at a sharp angle making advancement beyond this point difficult.

18
Q

what is a Hickman line?

A

central venous catheter used for feeding

placed via a SC tunnel from a point on the chest wall distant from point of entry of catheter into the vein.

19
Q

g of protein in 1g of nitrogen?

A

6.25g protein

20
Q

how can nitrogen loss be monitored?

A

check urinary urea excretion

21
Q

why might there be initial weight loss in pt reintroduced to food?

A

if pt has oedema or ascites, as expanded EC space diminishes.

22
Q

pts susceptible to refeeding syndrome- metabolic disturbance e.g. hypophosphataemia?

A

pts starved for more than 7 days
chronic alcoholics
pts with anorexia nervosa
pts who have lost >20% body weight in 3 mnths

23
Q

why is a glucose infusion needed in liver failure?

A

failure of gluconeogenesis

24
Q

considerations in feeding pts with acute pancreatitis?

A

was prev. though pts should be kept NBM and receive TPN to reduce pancreatic enzyme secretion, but this increases mucosal permeability and prolongs endotoxaemia.
infusion enteral feeds e.g. NG or NJ has little effect on pancreatic secretion and may reduce systemic inflam. response.

25
Q

characteristics of refeeding syndrome?

A

hallmark feature= hypophoshataemia
may also feature abnormal sodium and fluid balance, changes in glucose, protein, and fat metabolism, thiamine deficiency, hypokalaemia and hypomagnesaemia.

26
Q

L of fluid in ICF and ECF in average 70kg male?

A

ICF= 28L (2/3)
ECF= 14L (1/3)
IV= 3.5L
interstitial= 10.5L

27
Q

why do females have less fluid as a % of their body weight than males?

A

females have relatively more adipose tissue which is assoc. with lower amounts of water

28
Q

typical % of body weight which is water?

A

50-60%

29
Q

why does the volume of the blood remain the same when fluid is lost via sweating during exercise?

A

fluid lost from sweating means fluid loss from intravascular compartment as blood going to the sweat glands enables the production of sweat, so intravascular compartment becomes more concentrated, the osmotic pressure increases, and fluid is drawn out from the interstitial compartment to keep the blood volume the same.

30
Q

normal concentration of K+ in plasma?

A

3.5-5.3 mmol/L

31
Q

why is increased K+ lost in serious injury and illness?

A

increased excretion from high cortisol and aldosterone levels, and to protein and glycogen metabolism- protein b.down into aa means loss of -ve charge from ICF, so K+ also moves out of cells to maintain electroneutrality.

32
Q

what is the effect of giving glucose to malnourished pts, which can cause the features of refeeding syndrome?

A

glucose + release of insulin that occurs with it reverses depression of membrane pumps, increasing cellular uptake of K+, Mg2+, PO43- and Ca2+, which can cause dangerous falls in plasma levels.
also, same time net Na+ and water movement out of cells into circulation.
may be diminished cardiac reserve and high capillary permeability causing lethal fluid o.load and cardiac instability.

33
Q

why does NICE recommend NOT to use the colloid tetrastarch in pt resuscitation?

A

now thought that crystalloids are actually retained more than expected in circulation and in ill pts retain less colloid (increased capillary permeability?)

34
Q

Na+ content of 1L of normal saline (NaCl 0.9%)?

A

154mmol

35
Q

problems assoc with repeated use of sodium chloride 0.9% (isotonic saline)?

A

Na+ and water retention, more oedema than colloid?

hyperchloraemia which can cause hyperchloraemic acidosis, GI mucosal acidosis and ileus.

36
Q

benefits of using balanced crystalloid solutions e.g. Hartmann’s and Ringer’s in fluid resuscitation?

A

less Na+ and Cl- than isotonic saline, and already contain Ca2+, Mg2+ and K+.
contain lactate or other buffers which can help with significant acidosis often seen in circumstance of resuscitation.

37
Q

usefulness of glucose and glucose saline solutions?

A

correcting or preventing dehydration

can meet routine maintenance needs when used with K+

38
Q

risks with use of glucose and glucose saline solutions?

A

significant hyponatraemia if administered too quickly or too much fluid given

39
Q

problems assoc with colloid use?

A

renal dysfunction
coagulation disturbance
physiological disturbance

40
Q

what test can be used to assess if a pt is likely to respond to fluid therapy?

A

passive leg raise test- if pt’s BP improves following a passive leg raise, this is indicative of vol depletion.

41
Q

in IV fluid management, what timing is initial IV bolus given over?

A

less than 15 mins

42
Q

max IV fluid you can give in resuscitation before asking for expert hep?

A

2L

43
Q

Easy way to assess skin turgor?

A

Pinch the skin together on the forehead and on the chest, and see how quickly the skin regains its original appearance.

44
Q

risk with rapid reversal of hyponatraemia by giving IV fluids?

A

pontine myelinolysis= severe damage to myeline sheath of nerve cells in the pons, pt presents with dysphagia, dysarthria and paralysis.

45
Q

NICE recommendation for prescribing IV fluids in resuscitation?

A

rapid infusion over less than 15 mins of a 500ml bolus of an isotonic crystalloid- Na+ 130-154 repeated, if necessary (250-500mL boluses) until markers of vol status improve.

46
Q

if pt has received 4 boluses of IV crystalloid fluid resuscitation for hypovolaemic shock, and despite seemingly euvolaemic, still has low BP and high HR, what must be considered?

A

other causes of shock e.g. septic shock

need senior help and manage accordingly

47
Q

risks of using high volumes of NaCl in fluid resuscitation?

A

hyperchloraemic acidosis

volume overload

48
Q

difficulty in IV fluid replacement with variable output stoma?

A

giving IV fluids may be excessive if output from stoma falls, causing risk of pulmonary and peripheral oedema
if stoma output increases, IV fluid therapy without frequent reassessment may be insufficient, causing AKI.
also risk of hypokalaemia if inadequate K+ replacement given, and hyponatraemia espec. as likely to have high Na+ loss of stoma and so total body Na+ depletion as well as high ADH due to hypovolaemia and nausea in some pts, so urinary Na+ monitoring would be useful.

49
Q

what should an IV fluid management plan detail?

A

fluid and electrolyte prescription over the next 24 hrs and monitoring requirements including daily reassessments of clinical fluid status, lab values-urea, creatinine, electrolytes, and fluid balance charts, and weight measurement twice wkly.

50
Q

how can a pts IV fluid therapy needs for routine maintenance alone be managed?

A

pt needs 25-30 ml/kg/day of fluid, 1mmol Na+/K+/Cl- and 50-100mg glucose.

51
Q

consideration in timing of IV fluids for routine maintenance?

A

consider delivering during daytime hrs to promote sleep and wellbeing.

52
Q

in which pts might you consider prescribing less fluid than normal for routine maintenance?

A

older pts
pts with renal impairment/cardiac failure
malnourished pts at risk of refeeding syndrome

53
Q

elderly pt with normal cardiac function given IV fluids for routine maintenance. what are the risks?

A

hyponatraemia if excessive hypotonic fluids are given
volume depletion if insufficient Na+ and water given
volume overload if excessive Na+ and water given
AKI if inadequate Na+ and water given

54
Q

NICE guidance for initial IV fluid prescription for routine maintenance for a 70kg pt over 24hrs?

A

1.75-2.1 L of sodium chloride 0.18% in 4% glucose with K+ on day 1

55
Q

if a pt receiving IV fluid therapy for routine maintenance, what must be considered after 24 hrs?

A

whether their fluid and electrolyte requirements are being met, if not may discuss with a senior the need for nasogastric or PEG feeding, or continuing IV fluids
if further IV fluid therapy indicated check vol status, fluid balance chart and weight, serum urea, creatinine, Na+ and K+, and alter rountine maintenance prescription accordingly. seek advice from senior if in doubt.

56
Q

recommended contents of an IV fluid management plan?

A

Pt fluid an electrolyte requirements over the next 24 hrs, with reference to the 5 Rs
Pt volume assessment details
intended fluid prescription
monitoring requirements
when the plan is to be reviewed, and by whom

plan should be drawn up where possible in consultation with the pt and/or their family/carers. pt should understand why IV fluids are needed and be aware of what to look out for if fluids too much or insufficient. written info should be provided where possible, and plan should be communicated well with all of those involved in looking after the pt.

aslo include when to review, frequency of observations and measures to reduce need for IV fluids

57
Q

current position regarding colloid prescription?

A

hydroxyethylstarch (HES) solutions should not be prescribed to treat sepsis, burn injuries of critically ill pts as increased risk of kidney injury and mortality.

58
Q

when should IV fluids be stopped?

A

as soon as pt can meet their fluid and electrolyte needs orally or enterally

59
Q

what is normal urine output?

A

1ml/kg/hr, with minimum of 0.5ml/kg/hr

60
Q

likely urea: creatinine ratio in hypovolaemia?

A

> 100:1

as both freely filtered at glomerulus but enhanced reabsorption of urea at PCT is hypovolaemic.

61
Q

how many ml of fluid are lost as insensible losses daily?

A

500 ml

62
Q

parameters to observe when determining a pt’s fluid status?

A
BP and postural changes
HR
RR
CRT
skin turgor
mucous membranes-dry/moist, pink/pale?
fluid balance charts
presence of peripheral or pulmonary oedema
Us and Es
JVP
thirst
NEWS (national early warning score)
63
Q

most useful immediate observations to assess fluid status of a pt?

A
mucous membranes
CRT
BP
HR
urine colour
64
Q

causes of volume depletion in sick pts?

A
vomiting
diarrhoea
not drinking enough fluids
high output GI stoma
DM
DI
diuretic use
burns
trauma
65
Q

importance of BMI in calculating pt’s fluid requirements?

A

if obese, requirements should be calculated based on ideal body weight and not actual body weight

66
Q

Pts at risk of complications of IV fluid therapy?

A
elderly/frail
low BMI
obese
multiple co-morbidities
HF
renal impairment-grade 3A or worse
liver disease/cirrhosis
diabetes
48-72 hrs post surgery
unconscious
67
Q

consequences of fluid mismanagement to be reported as critical incidents?

A
pulmonary oedema
peripheral oedema
hyponatraemia
hypernatraemia
hypokalaemia
hyperkalaemia
hypovolaemia

others= thrombophlebitis and arrhythmias

68
Q

classical presentation of refeeding syndrome?

A

acute congestive cardiac failure precipitated by fluid shifts occurring from reintroduction of carb after prolonged starvation.

biochemically= reduction in phosphate, potassium and magnesium.

cardiac, respiratory, GI and neurological function impaired.

69
Q

consequence of reduced phosphate in refeeding syndrome?

A
arrhythmias
acute resp failure
confusion
HF
lethargy
rhabdomyolysis
seizures
70
Q

consequence of reduced potassium in refeeding syndrome?

A
arrhythmias
cardiac arrest
polyruia/polydipsia
resp deression
ileus 
wkness
71
Q

consequence of reduced magnesium in refeeding syndrome?

A
arrhythmias
confusion
altered bowels
ataxia
muscle tremors
wkness
72
Q

NICE RFs to identify pts at high risk of refeeding syndrome?

A

1 or more of:
BMI less than 16
unintentional weight loss more than 15% within last 3-6mnths
little or no nutritional intake for more than 10 days
low levels of potassium, phosphate or magnesium prior to feeding

or 2 or more of:
BMI less than 18.5
unintentional weight loss >10%
little or no nutritional intake for more than 5 days
history of alcohol abuse or drugs including insulin, antacids, diuretics or chemotherapy.

rapid weight loss= biggest RF

73
Q

explain the metabolic processes occurring in the starvation state and then what happens to result in the refeeding syndrome?

A

prolonged starvation: insulin drops, activating hormone sensitive lipase- fat stores broken down. FA used in KB prod and glycerol for gluconeogenesis. Muscle also broken down to aa for gluconeogenesis. And phosphate stores depleted.

Carb reintroduction- insulin rapidly increases for glycogen, fat and muscle synthesis from glucose. This requires phospahte, and drives phosphate, potassium, magnesium and water into tissues, and sodium out.
subsequent oedema and
low phosphate reduces ATP prod. impairing cardiac muscle function
and reduces 2,3-DPG in red cells, reducing tissue oxygenation
thiamine use also increased.

74
Q

how is refeeding syndrome prevented?

A

diet re-introduction at SLOW rate, e.g. as low as 5-10kcal/kg/day in anorexic pts.
IV phosphate infusion before feeding
parenteral multivitamins as important in carb metabolism
rigorous checking of phosphate, potassium and magnesium levels.