Prescribing IV Fluids and Blood Products Flashcards
What is the Clinical Approach to prescribing IV fluids?
1 A and 5 s: Assess and identify which of the 4 Rs it is then Reassess at the end
- Assessment
- Resuscitation
- Routine maintenance
- Replacement
- Redistribution
- Reassessment
What are important clinical assessments to take when Assessing a patients fluid status
- History
- N+V, diarrhoea → loss of fluids and electrolytes
- Respiratory rate >20 breaths per minute
- May be increased in loss or intake is too low
- ketone bodies can be produced to provide energy → could be present in acute kidney injury resulting in ketoacidosis
- Dry mucous membranes and loss of skin turgor
- skin turgor more useful in younger patients - anterior fontanel in neonates
- Capillary refill time >2 seconds and/or peripheries are cold to touch
- Pulse >90 bpm – weak; thready
- sensitive marker
- SBP <100 mmHg – postural hypotension
- if it drops by more than 20mmHg
What are other assessments of a patients fluid status?
- Passive leg raising suggesting fluid responsiveness
- if the patients symptoms get better when the legs are raised it suggests the patient may be dehydrated
- if the symptoms worsen may suggest overload - heart failure
- ↑JVP
- ↓Urine output
- Acid-base disturbance - effects respiratory rate as ell
- Serum urea and electrolytes – AKI
- raised urea and electrolytes raised and other deranged electrolytes
- Serum osmolality
How is resuscitation carried out?
what is used?
- Crystalloids (Na 130–154 mmol/l)
- Bolus of 500 ml over less than 15 minutes (250ml if older, frail or heart failure)
- Repeat boluses as appropriate
- Involve HDU/ITU when up to 2L of fluid (1L if older, frail or heart failure) with no response
What are commonly used Crystalloids and their composition?
- Sodium Chloride 0.9% → 154 mmol/l of Na+ and Cl- (1:1 ratio)
- osmolarity of 308, pH between 4.5- 7.0
- Sodium Chloride 0.18% 4% glucose → 154 mmol/l of Na+ and Cl- (1:1 ratio); 222 mmol/l glucose (40g) (Dextrose Saline)
- osmolarity of 284, pH 4.5
- should be used as maintenance fluids
- Hartmann’s → 131 mmol/l Na+ and 111 mmol/l Cl- (1.18:1 ratio);
- 5 mmol/l K+, Bicarcb 29 (lactate), 1.4 mmol/l Ca2+
- pH 5-7.0, Osmolality of 278
- 5% glucose
- 278 mmol/l (50g)
- pH 3.5 -5.5, osmolality 278
What should maintenance fluids consist of?
- 25–30 ml/kg/day of water + 1 mmol/kg/day of potassium & sodium & chloride + 50–100 g/day of glucose to limit starvation ketosis
- 20–25 ml/kg/day fluid - older or frail; renal impairment or cardiac failure; malnourished and at risk of refeeding syndrome
- Sodium Chloride 0.18% in 4% Glucose with 27 mmol/l Potassium
- Most patients do not require >3L fluid in 24 hours
When are replacement fluids needed?
When there are greater than expected physiological loses
- Vomiting and nasogastric tube loss
- Biliary drainage losses
- Pancreatic drain or fistula
- Diarrhoea or excess colostomy loss
- Jejunal loss via stoma or fistula; high/low volume ileal loss via new/established stoma
- Inappropriate urinary loss (polyuria)
this adds to maintenance needs if losses are greater than expected
What are is Redistribution and what are causes of it?
When fluid is on board but is in the wrong space - this may need you to add or subtract from the maintenance needs
- Gross oedema
- Severe sepsis (peripheral pooling)
- Hyponatraemia or hypernatraemia
- Renal, liver and/or cardiac impairment
- Post-operative fluid retention and redistribution
- Malnourished and refeeding issues
What is the NICE pathways for IV fluid therapy?
Prescribe IV fluids in this scenario (pointing out any concerns)
A 65-year-old man presents to the emergency department because he is feeling weak and unwell. He has had diarrhoea and vomiting for the past 2 days following a takeaway meal.
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Examination:
- He is speaking in full sentences; Oxygen Sats 96% on room air
- Temperature 37.1°C, HR 102/min and rhythm regular, BP 102/60 mmHg. Weight 70 kg.
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Investigations:
- Na+ 126 mmol/L (137–144), K+ 2.4 mmol/L (3.5–5.3), U 12.0 mmol/L (2.5–7.0), Cr 97 µmol/L (60–110).
- Low Na+ most likely due to the N+V
- Low K+ (may degenerate into cardiac arrest)
- Raised Urea,
- Normal Creatinine
- Tachycardia and hypotension
→ wouldn’t give any glucose as it would dilute the sodium further
Would prescribe 1 litre 0.9% Sodium Chloride + 40 mmol Potassium Chloride over 4 hours (fastest you can prescribe potassium is 10mmol of KCl per hour)
What is the fastest rate which you can prescribe Potassium Chloride
10mmol of KCl per hour
Prescribe IV fluids in this scenario (pointing out any concerns)
A 77-year-old woman presents to the emergency department with a history of right sided weakness which she noticed on waking. She also has slurred speech and a weak swallow. PMH. Hypertension. DH. Amlodipine; Ramipril
Further assessments are being performed and she is nil by mouth.
Weight = 60 kg
1.5 litres of 0.18% Sodium Chloride + 4% glucose over 24 hours
→ she is nil by mouth therefore she needs glucose to prevent development of ketoacidosis
→ she has cardiac problems and is an older more frail person therefore don’t want to strain her heart lower end of maintenance fluid scale 20-25ml/kg/day would be exactly 1.2 litres with additional to consider losses
Prescribe IV fluids in this scenario (pointing out any concerns)
A 55-year-old woman presents to the emergency department with a history of recurrent palpitations. She was started on a new tablet 6 weeks ago. PMH. Resistant Hypertension. Coronary Artery Disease DH. Amlodipine; Ramipril; Indapamide; Bisoprolol; Aspirin; Atorvastatin; Spironolactone.
- Examination - Unremarkable
- Investigations - Na+ 136 mmol/L (137–144), K+ 6.8 mmol/L (3.5–5.3), U 7.2 mmol/L (2.5–7.0), Cr 70 µmol/L (60–110).
- ECG = Broad QRS complexes
- She has been put on a cardiac monitor.
- hyperkalemia is the biggest concern
- increased risk with Spironolactone and Ramipril
- mild hyponatremia
→ Prescribe Calcium gluconate or (10% ) Calcium chloride (more calcium) to protect the heart
→ Prescribe IV dextrose (50%) and IV insulin (50 units): insulin drive potassium into cells, you give glucose with it to prevent hypoglycemia
Prescribe IV fluids in this scenario (pointing out any concerns)
A 76-year-old man, an inpatient at UHSussex, was recently started on insulin to improve control of diabetes. He was found to be unresponsive by the healthcare assistant. PMH. Type 2 Diabetes. Hypertension. DH. Novomix 30 BD; Amlodipine; Ramipril; Atorvastatin
- Examination – Unresponsive; Pulse 110 bpm; BP 152/94; Oxygen sats 93% on air.
- Investigations – Capillary blood glucose = 1.9 mmol/L
→ IV 10% glucose quickly 150ml over 10 minutes
→ or IM glucagon
Prescribe IV fluids in this scenario (pointing out any concerns)
33-year-old man presents to the emergency department with a 3 day history of melaena. PMH. Recent cruciate ligament surgery. DH. Ibuprofen 400 mg PO 8-hrly for the past week.
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Examination
- He is speaking in full sentences; Oxygen Sats 96% on room air
- Temperature 36.4°C; HR 132/min and rhythm regular; BP 82/50 mmHg.
- PR = Melaena.
- Would need fluid resuscitation - 0.9% NaCl 500ml
- blood pressure is very low
What are clinical features of transfusion reactions?
