Fluid Balance Problems

Question 1

What will you find on examination of a patient who is dehydrated/in shock?

Answer 1

End of the bed:
Reduced Skin turgidity 
Hands:
Tachycardia
Hypo-tension with Postural Drop 
Increased Capillary refill time 
Cool peripheries
Face:
Dry Mucous Membranes
Sunken Eyes 
Abdomen:
Reduced urine output
Legs:
Cool peripheries

Question 2

What will you find on examination of a patient with fluid overload?

Answer 2

Neck:
Raised JVP
Chest:
Tachypnoea
Bibasil Crepitation’s
Pulmonary Oedema on CXR
Legs:
Pitting oedema in sacrum/ankles/legs

Question 3

What investigations will you order in a patent you suspect is dehydrated?

Answer 3

Bedside:
Urinary Catheter or input/output monitoring - Urine Output should be >0.5ml/kg/hour
Full set of observations

Bloods:
FBC - Raised Hb, Haematocrit can indicate dehydration
U&E – Hypernatremia or Hyponatraemia can be due to fluid overload (Dilution) or fluid depletion (increasing the effective concentration), In dehydration the Urea: Creatine Ratio will be raised (Urea is reabsorbed during water reabsorption, so in hypovolaemia urea is reabsorbed more than creatinine, increasing the ratio). However, both may be raised
LFT’s - Raised Albumin in dehydration due to increased effective concentration
Arterial/Venous Blood Gas - Raised lactate (organ hypoperfusion)
Blood osmolality – Reduced in fluid overload and raised in dehydration

Daily Monitoring should be done for patients on fluids. This includes a clinical assessment, fluid balance chart and U&E’s

Question 4

What is the acute management of Dehydration

Answer 4

Volume Resuscitation – for replacement of losses
Give 500ml saline over 15 mins
Reassess ABCDE and give again until blood pressure normal or 2L given.
If BP not returning to normal after 2L, get help
Only give 250ml in heart/renal failure

Question 5

What is the non acute management of Dehydration

Answer 5

Firstly, need to know daily requirements:
Fluid - 30ml/kg – Reduced if elderly or in CCF/Renal Failure to 20ml/kg
Na, K, Cl – 1mmol/kg
50-100 Glucose/day -Only if NBM, if eating food, they don’t need glucose

Average 70kg man needs:
70mmol Na, CL, K
2.1l Fluid
75g glucose

Patients normally eat/drink on their own. Only give fluids if they are unable to meet their own requirements e.g. won’t eat/drink enough or if they are NBM.

Secondly need to know the electrolyte levels of each fluid
1l saline – 154NA 154CL per bag
1l dextrose 5% - 50g Glucose per Bag
1l dextrose 10% - 100g Glucose per bag
1l 0.18%saline in 4% Dextrose - 30NA, 30CL, 40g Glucose
Hartman’s – 131Na, 111CL, 5K, 29HCO3
K+ can be added to each litre bag at 20 or 40 mmol/l

Nice recommended basic maintenance dose:
30ml/kg NACL 0.18% in 4% dextrose + 27mmol/l K
Daily Monitoring