12. IV Fluids: Choosing and Prescribing Flashcards
Which of the following are true?
a) 1L of IV 5% dextrose will increase circulating volume by about 200mL
b) 1L of 0.9% saline contains >150mmol of sodium
c) 500mL IV bolus of dextrosaline is an appropriate fluid bolus for a volume deplete patient
d) Bile fluid contains more sodium than gastric contents
a)
b)
c)
d) True
What is the 2/3 rule of body water?
Describe the 3 types of IV fluid that can be prescribed to replace volume?
Total body water (TBW) is approx 60% of total body weight. 2/3 of TBW is intracelullular fluid (ICF), 1/3 of TBW is extracellular fluid (ECF). 2/3 of ECF is interstitial and 1/3 is vascular. Fluid moves between compartments.
1. Crystalloids: water with varying degrees of salts. 0.9% saline, 5% dextrose, 4%/0.18% dextrose/saline. Can add K to these 3. Ringer’s lactate solution, Hartmann’s solution, Propriatory infusion solutions. Can’t add K to these.
2. Colloids: protein rich versions of crystal loads with some salts in. Stay in vascular compartment better because have HMW protein content as well as salt/electrolytes. E.g. Gelofusine. Small risk of anaphylaxia
3. Blood products
What are some indications a patient may need fluid resuscitation? And that a patient may be hypervolaemic?
What are normal, daily fluid and electrolyte requirements for maintenance fluids? What if the patient is obese?
Systolic BP <100mmHg (hypotension, HR >90bpm (tachycardic), cap refill >2s or cold peripheries, resp rate >20bpm, NEWS ≥5. 45 degrees passive leg raise test +ve. Low/absent JVP, decreased skin tugor, oliguria, weight decrease. Also DH + clinical examination.
Hypervolaemic: tachycardia, raised JVP, pulmonary oedema, pleural effusion, ascites, peripheral oedema, weight increase.
25-30ml/kg/d water, 1mmol/kg/d sodium, potassium, chloride., 50-100g/d glucose to limit starvation ketosis. Obese: adjust IV fluid prescription to their ideal body weight
If you give too much 0.9% saline, what can happen?
What is the maximum amount of sodium you should give a patient per hour?
What amount should you not exceed per day for routine fluid maintenance?
What are the different fluid statuses?
Hyperchloraemic acidosis due to build up of HCl (NaCl + H2O ⇌ HCl + NaOH), due to difference in composition of 0.9% saline and plasma
20mmol/hr.
30ml/kg/d and less for older/frail/renal impaired/cardiac failure
Euvolaemic (normal), hypovolaemic (dry - give colloids/crystalloids - emg or maintenence?), hypervolaemic (wet)
What kind of fluid would you use for resus?
The rate (speed) of fluids can be prescribed (ml/hr) with volumetric pumps. What are the different cannula colours and sizes that can be used to infuse fluids?
How does sepsis affect the body’s fluid?
Crystalloids that contain sodium 130-154mmol/l, bolus of 500ml over <15mins. If severe sepsis consider human albumin solution 4-5%.
Time to infuse 1L:
- *22G** Blue 22mins
- *20G** Pink 15mins
- *18G** Green 10mins
- *16G** Grey 6 mins
- *14G** Red 3.5mins
Dilates everything, BP drops, have fluid but no vascular tone b/c of all the inflammatory mediators
All patients receiving IV fluids need regular monitoring which should include what?
Why is urine-sodium monitoring helpful for fluid status reassessent?
List sources of fluid input and output.
Clinical fluid status, Us&Es, fluid balance charts, weight measurement 2x/week.
Can help to identify whole-body sodium depletion in patients who have high-volume GI losses (when dry, activate RAAS to reabsorb all Na b/c it gives volume in blood), and in assessing odematous patients. If receiving IV fluids containing chloride >120mmol/l monitor serum chloride conc daily!
Input: oral, NG/PEG/PEJ, IV
Output: urine, stools, drains, insensible losses (breathing)
How often should you prescribe if a patient is well vs unwell?
What are some risks of IV therapy?
What details do you need to clarify when you prescribe fluids?
Well + stable: over longer duration. Unwell: shorter duration with regular reassessments.
Fluid overload, electrolyte imbalance, infection, phlebitis/thrombophlebitis, infiltration/extravasation, colloids = small anaphylaxis risk
Date/time, fluid type, volume, drug added (e.g. K) (and dose), infusion rate, route, signature and bleep, update nursing team
When should you consider a blood transfusion?
What are some risks of blood transfusions?
Who is CMV -ve blood indicated for?
Massive/ongoing haemorrhage, Hb <8 (debatable) or Hb 8 - 10 and symptomatic/cardiac, resp or cerebrovascualr disease
Immune reactions (acute/delayed haemolytic reaction, anaphylaxis etc.), infections, volume, electrolytes (hyperkalaemia (blood contains lots of K), hypocalcaemia, worse coagulopathy, iron excess)
For CMV -ve recipients of allogenic SC and bone marrow transplants, and CMV -ve pregnant women, intrauterine transfusions, newborns weighing <1200g. Maybe for CMV -ve people with HIV, organ recipients, neutropenia…)
Who is irradiated blood indicated for?
Why might blood be transfused with furosemide (20-40mg IV with every second unit transfused)?
If you don’t know what fluid, what is the most common suggestion? And if low BP? And if stable?
Allogenic haemopoetic SC transplant recipients, autologous SC transplantation recipients, Hodgkin lymphoma, aplastic anaemia, after purine analogues/antagonists/anti-CD52. Not for autoimmune disease or after solid organ transplants.
Diuretic, to help pt pee out additional blood but retain cells; for those at risk of circulatory overload or pulmonary oedema.
0.9% saline. Low BP: 500ml stat over 15m. Stable: 1L bag saline and 2L of 5% dextrose over 8 hours.
Does this patient need fluids?
Emergency call:
A: patent
B: sats 97% OA, chest clear
C: BP 68/45, PR 124, HS 1+2+0, JVP low
D: GCS 14/15 (E4/V4/M6), BM 8
E: No clear source of bleed
This person needs resus since BP v low and pulse fast so give fluids.
What would you give this patient?
Emergency call:
A: patent
B: stats 97% OA, chest clear
C: BP 68/45, PR 124, HS 1+2+0, JVP decrease
D: GCS 14/15 (E4/V4/M6), BM 8
E: massive fresh haematemesis
500ml of saline bolus, check Hb because they could become anaemic then symptomatic and need transfusion.
What type of fluids would you give this patient?
Male, 50, young stroke, unsafe swallow - kept NBM, no other PMH, no DH, clinically euvolaemic, normal U+Es.
Needs maintenance fluids, consider Hartmann’s, Lactate’s etc. Traditional approach: 1 salt + 2 sweet over 1 day (1x 1L 0.9% sodium chloride, 2 x 1L 5% dextrose 8 hourly). K replacement guided by plasma levels, but if normal replace with daily requirements (60mmol)). Think about comorbidity. Need to consider his background - heart failure? Vascular disease?
What would you deduce from these obs?
Small bowel obstruction - ‘drip and suck’ (removing GI contents)
Kept NBM, awaiting surgery
No PMH or DH, BP 102/68, PR 108, cool peripheries, JVP decrease
Na 138, K 3.2, Ur 10.2 (previously normal), Cr 140 (previously normal), urine output 10ml/hr
Slightly tachycardic. Drip and suck = they have increased fluid requirement. Na normal, K low, Cr raised, if 70kg should be peing 0.5ml/kg/hr so around 30ml.
Thus oliguric, low K, raised Ur and Cr
What one initial fluid would you prescribe this patient?
A 76yo man has recently had a total colectomy and ileostomy formation 3 days ago for a colonic carcinoma. He has slowly been restarted on oral fluids, and in the last 24hrs has managed only 500ml. His new ileostomy produced an output of 3L, and his surgical drain 200ml in the last 24 hours. His urinary catheter has been recently removed, but he reports a urinary output of around 1L yesterday. He has no other PMH or DH.
BP 136/88mmHg without postural drop, HR 84/min. Temp 36.2C, Na 138, K 4.2, eGFR >90.
0.9% sodium chloride with 20 or 40 mmol/L KCl, 1L over 2-6 hours, date and time, and sign.
