Fluid Balance and Nutrition Flashcards
A 70 kg patient is 1 day following total hip replacement. He has not started eating and drinking. He is being rehydrated with dextrose/saline (4 per cent dextrose and 0.18 per cent saline). Which one of the following best describes this type of fluid therapy?
A. It is an inappropriate fluid therapy for a postoperative patient
B. It contains 120 mmol of Na+ ions
C. Potassium supplementation is not required
D. Its osmolality is almost isotonic with plasma (286 mOsm/kg)
E. It has a pH of 7.35
D. Its osmolality is almost isotonic with plasma (286 mOsm/kg)
A regime of Dextrose and Saline is a useful fluid therapy in the post operative period as it does not cause water or salt overload. It has a similar osmolality to plasma and is very useful for replacing water loss, which is common after surgery.
It is slightly alkaline and contains around 30mmol of Na and Cl ions. It contains no Potassium so this must be substituted if the patient has not yet established oral intake.
A 22-year-old man is admitted following a stab injury to the right groin. He is
bleeding profusely from the wound. His blood pressure is 80/40 mmHg and his
pulse is 140 beats/min. He is agitated and mildly confused. His skin is cool and
mottled. In this scenario, which is the best mode of fluid delivery?
A. Left subclavian central line
B. Long saphenous vein cut down
C. Right internal jugular approach central line
D. Left femoral long line
E. Two wide-bore cannulae inserted bilaterally to the antecubital fossae
E. Two wide-bore cannulae inserted bilaterally to the antecubital fossae
The key to resuscitation in a patient who is this hypovolaemic is to get the access which will give you the maximum resuscitation capacity.
Central lines such as (A) and (C) are long narrow lumen tubes and so cannot achieve a high flow rate.
A long line (D) suffers from the same restriction.
two large bore cannulae in the ACF (E) will enable the most rapid route of resuscitation.
If peripheral access is not possible then another form of access will be sought such as a cut down (B) or intraosseus access.
For the patient described in Question 2 (class III shock, penetrating trauma patient), which one of the following statements regarding fluid resuscitation is most correct?
A. Hartmann’s solution should not be used.
B. The best fluid replacement is cross-matched blood
C. It is mandatory to use colloid over crystalloid
D. Colloids are preferable to expand the intracellular volume
E. Crystalloids should be avoided as they may cause anaphylaxis
B. The best fluid replacement is cross-matched blood
This comes down to the principle of ‘like for like’, if the patient is losing blood then the best option is to replace with blood (B). This patint is in class II shock and so has likely lost in excess of 30% of his circulating volume and needs blood replacement.
two litres of warmed hartman’s is the standard ATLS inital treatment, so (A) is incorrect.
Colloid is going out of fashion as it has dubious benefits and carries a higher risk of anyphylaxis over crystaloid, so (C) and (E) are wrong. (E) is dubious at best, either way the first step is to give crystaloid.
A 40-year-old man weighing approximately 70 kg is being kept nil by mouth due
to small bowel obstruction. He is afebrile at 36.7 °C. Which of the following
regimens best describe the patient’s requirements over the first 24 hours?
A. 1–2 mmol/kg of sodium is required
B. 0.5–1 mmol/kg of potassium is required
C. At least 100–1000 kcal/kg/day are required
D. 2700 mL of water is required
E. None of the above
E. None of the above
here we have a scenario that is highly suggestive of an occult fluid loss, likely due to sequestration in the bowel as a result of obstruction.
A typical healthy adult will require 1-2.5l of water, with 1-2 mmol/kg Na and 0.5-1 mmol/kg K. As the fluid lost in the bowel will be of a large amount and salt rich this patient’s requirements will likely significantly exceed these figures.
30-40 Kcal/kg/day would be a normal energy requirement in the abscence of sepsis. We can therefore see that none of the options here are correct.
This patient needs 0.9% normal saline (150mmol/L Na) with an addition of 20-40mmol KCl in each litre. Serial blood tests and clinical examination will guide the rate of fluid replacement and the addition of any other electrolytes.
A 68-year-old man is 6 days following open anterior resection with defunctioning ileostomy. The patient is afebrile at 36.7 °C. He is eating and drinking normally. The nursing staff inform you the stoma output is 3 L/day. His mucous membranes are dry and the patient feels thirsty. Which one of the following statements regarding fluid therapy is most correct?
A. Continue to push oral fluids
B. 5 per cent dextrose is most appropriate given nutritional content
C. 0.9 per cent normal saline with potassium supplementation is most
appropriate
D. Potassium supplementation is not required
E. None of the above
C. 0.9 per cent normal saline with potassium supplementation is most
appropriate
The high output loss from the stoma will also be salt rich, any increase in oral fluids (A) will just be lost via the stoma. This patient needs replacemtn with a similar fluid, which would be normal saline with potasium (C)
Dextrose (B) doesn’t replace any of the ions
The patient is losing potassium via the stoma so it should be replaced (D)
A 59-year-old woman is admitted with central abdominal pain. Serum amylase is 1800 IU/L. Her initial Glasgow Coma Scale score is 4. You are asked to review her the next day as the nurses have noticed that her urine output has been just 15 mL in the past 3 hours. The rest of her observations are as follows:
• Blood pressure = 105/45 mmHg
• Pulse = 113 beats/min
• Respiratory rate = 28 breaths/min
• Saturation 93 per cent on 8 L of oxygen
On auscultation of her chest you hear widespread crepitations. What is the most appropriate next course of action?
A. Fluid restriction
B. Colloid bolus
C. Furosemide
D. Transthoracic echocardiogram
E. Central line insertion
E. Central line insertion
This patient has severe pancreatitis,which is causing the observed widespread inflammatory response. Often these patients will present rather well and then deteriorate over 24-72hrs, as this patient has.
The initial step with managing pancreatitis is good fluid resuscitation, as there are extensive third space losses, as well as external losses in the form of vomiting, seating and reduced intake.
This patient sems to be afected by pancreatitis induced Acute Lung Injury, a similar condition to ARDS, where there is fluid leakage into the lung alveoli, compromising respiration.
With ALI it is important to set up a central venous line to measure cardiac pressures, as this is the onlt method of identifying ALI as oppossed to cardiac failure.
a fluid bolus (B) would make the fluid overload worse.
Fluid restriction (A) would cause further kidney injury
Frusomide (C) would deplete the vascular fluid but not help the sequestered third space fluid. It is also renal toxic.
The patient does need an echo (D) but the central line is the first step.
The patient in Question 6 (Pancreatitis with GCS 4 and low urine output) had a central line inserted and was transferred to the
high-dependency unit. Her observations remained the same and in the last hour only 5 mL of urine is passed. Her saturations remain poor. Her central venous pressure initially is 11 cmH2O. You attempt a fluid bolus of 250 mL of colloid, following which her central venous pressure increases and remains at 15 cmH2O. Her urine output over the next hour is 10 mL. Which one of the following statements is the most correct?
A. This patient is septic
B. Noradrenaline is the next most appropriate step
C. A further fluid bolus is warranted
D. This patient has left ventricular failure
E. This patient will require dialysis
D. This patient has left ventricular failure
The salient point here is that this patient has had a sustained rise in CVP following a fluid bolus, this is a good indication of a fluid overloaded system. Despite being fluid overloaded her urine output is still abnormally low and her BP has been consistently low, the only explaination here is that there is a left ventricular failure.
With CVP measurement there is no defined normal range, it is more useful to monitor it’s response to a fluid bolus. If the CVP doesnt change it indicates hypovolaemia, if it rises ny 2-4cmH2O and then reverses after around 30 minutes the patient is Euvolaemic, if there is a sustained rise of greater than 5cm H2O it indicates cardiac failure.
A 22-year-old patient is brought to the emergency department in class III shock following multiple penetrating stab injuries to the torso, chest and abdomen. He undergoes an emergency thoracotomy and laparotomy. In theatre he requires a total of 30 units of blood. Which of the following is the best statement regarding complications of massive blood transfusion?
A. Thrombocytosis is inevitable
B. Depletion of factor XI and X is a common problem
C. Hypocalcaemia may ensue
D. Hyperkalaemia is uncommon
E. Hypothermia is rare
C. Hypocalcaemia may ensue
a massive blood transfusion is defined as the replacement of a patient’s entire circulating volume (.10 units) over 24hrs. There are additional complications with massive transfusion scenarios due to differences in the stored blood when compared to circulating blood.
Stored blood is deficient in factor V and VII as this rapidly degrades in storage. Plateletes and cryoprecipitate should be used to supplement massive transfusion. Otherwise DIC is a possibility.
Blood is stored a low temprature so hypothermia is a risk, even with warming protocols.
There can be hyperkalaemia in massive transfusion as stored blood has a hig potassium content.
The Citrate in stored blood binds calcium to prevent clotting, when there is a massive transfusion this citrate can effectively chelate calcium out of the circulation, so answer (C) is the correct one here.
A 70 kg, 56-year-old patient is 12 hours following a difficult colectomy for colorectal carcinoma. During the procedure, the patient experienced bleeding, which needed to be controlled with diathermy coagulation. You are asked to review the patient who has become increasingly unwell and is complaining of abdominal pain. Physical examination reveals marked left-sided tenderness. His pulse is 130/min and blood pressure is 80/40 mmHg. He is pale and clammy and the urine output is 15 mL for the last hour. His haemoglobin is 6.0 g/dL having been 13 g/dL preoperatively. You decide to start rehydration using Gelofusine colloid. Which one of the following is the most appropriate statement regarding fluid resuscitation in this patient?
A. Colloid is a useful fluid therapy as it rapidly enters the intercellular
compartment
B. Colloid decreases the plasma oncotic pressure
C. Colloid is less likely than crystalloid to induce allergic reactions
D. Colloids are better than crystalloids as they are of low molecular weight
E. Colloid should be changed for blood as soon as is possible
E. Colloid should be changed for blood as soon as is possible
It is likely that this patient is experiencing a reactionary haemorrhage as some initial clot has failed and there is a new bleed. in keepong with the principle of ‘like with like’ this patient should recieve blood as soon as possible (E).
Colliods are often used as a first measure while cross-matched blood is being sourced. Colloids are thought to stay in the intravascular compartment with greater affinity than crystaloids, so (A) is incorrect.
Colloids increase the plasma oncotic pressure (B) and maintain fluid in the plasma.
Colloid is more likely to cause allergic reactions (C)
Obviously colloids have a higher molecular weight than crystaloids (D)
You are called to review a 70 kg, 60-year-old man who is 2 days following an
emergency laparotomy for adhesion-related small bowel obstruction (adhesiolysis). He is currently being infused with Hartmann’s solution (Ringer’s lactate). Which one of the following statements regarding this type of fluid therapy is most appropriate?
A. It contains more sodium than normal 0.9 per cent saline solution
B. It does not contain bicarbonate
C. 3 L contains sufficient K+ ions for this patient
D. It has a composition that is closer to plasma than dextrose saline
E. None of the above
D. It has a composition that is closer to plasma than dextrose saline
Hartmann’s soloution (Ringer’s lactate) is designed to be closer to plasma than other fluids (D). It is composed of;
- Na+ = 131 mmol/L
- Cl– = 111mmol/L
- HCO3– = 29mmol/L
- K+ = 5mmol/L
- Ca2+ = 2mmol/L
- Lactate = 29 mmol/L
It is the first choice replacemtn fluid in a trauma scenario as per ATLS guidelines. Normal saline contains 150mmol/L of sodium so (A) is incorrect. It can be seen that (B) is incorrect.
3 litres of Hartmans would only contain 15mmol of potassium which is far below the normal requirement of 0.5-1mmol/L/Kg, as this patient is not 15-30kg…
It is for the low salt content that Hartmann’s is not a good choice for maintence fluid
You have been asked to see a 72-year-old Caucasian woman who is 52 hours
following uncomplicated laparoscopic cholecystectomy for gallstone disease. She was found unconscious on the ward with generalized tonic-clonic seizures,
requiring 20 mg diazepam. Her sodium level is 112 mmol/L. During surgery she
received 3 L of 5 per cent dextrose with 20 mmol/L potassium chloride. Her
potassium and urea and creatinine are within normal limits. There are no signs of heart failure. Her plasma osmolality is 265 mOsm/kg and her urinary osmolality is 566 mOsm/kg. Which of the following is the most likely cause for her low sodium?
A. Excess 5 per cent dextrose
B. Addison’s disease
C. Syndrome of inappropriate antidiuretic hormone secretion
D. Nephrotic syndrome
E. Congestive cardiac failure
C. Syndrome of inappropriate antidiuretic hormone secretion
SIADH is charecterised by hyponatremia, inappropriately elevated urine osmolality (>200 mOsm/kg), excessive urine sodium excretion (urinary Na >30 mEq/L), and decreased serum osmolality.
These findings occur in the context of a euvolaemic patient without signs of oedema. The hyponatremia is due to excessive water not the sodium itself so fluid restriction is the treatment.
Of the other options here, excess 5% dextrose would not cause the concentrated urine (A). Addison’s would have elevated potassium levels in the serum (B). Nephrotic syndrome (D) and cardiac failure (E) would have oedema.
A 45-year-old patient is 1 week following an attack of severe acute pancreatitis.
He has been unable to start eating as this precipitates severe pain. Physical
examination reveals a soft abdomen with epigastric tenderness. Bowel sounds are scanty. He is afebrile. His amylase in normal and C-reactive protein is 200 mg/L. Which of the following statements regarding management of nutrition is correct?
A. No supplementary nutrition is required
B. Total parenteral nutrition should be commenced
C. Nasogastric feeding should be commenced
D. Nasojejunal feeding should be commenced
E. None of the above
D. Nasojejunal feeding should be commenced
A large number of in-patients are under nourished, and it has serious repurcussions for recovery and complications, which increases the length of stay. (A) is not a good answer
Enteral feeding is prefered to TPN (B), TPN should be reserved for when enteral feeding has been unsucessful. TPN carries a risk of thrombus, sepsis, metabolic problems and lipid overload, and there is the issues with the non-use of the alimentary tract.
NG feeding (C) would likely continue to aggrevate the situation and increase aspirates.
NJ feeding (D) is the best option as it delivers nutrition further along the ailmentary tract were it is far les likely to cause aspiration.
After a multidisciplinary review, a 55-year-old patient is commenced on enteral
feeding. After 24 hours, he complains of severe diarrhoea. What is the most
appropriate step in managing this patient?
A. Speed up enteral feed
B. Stop the enteral feed
C. Slow down the enteral feed
D. Continue the enteral feeding at current rate and exclude other causes
E. None of the above
C. Slow down the enteral feed
A 75-year-old Caucasian man is on the intensive care unit following an emergency Hartmann’s procedure for an obstructing sigmoid carcinoma. He is currently 6 days post-procedure. His past history includes chronic obstructive pulmonary disease. The nursing staff report high nasogastric aspirates despite slow enteral feeding at 10 mL/hour. On examination his abdomen is mildly distended, and generally tender with no peritonism. His stoma looks healthy but has not started to work yet. His bowel sounds are absent. What is the best way to manage this patient’s nutrition?
A. Continue nasogastric feeding
B. Site nasojejunal tube and start feeding
C. Commence total parenteral nutrition
D. Site a percutaneous gastrostomy tube
E. None of the above
C. Commence total parenteral nutrition
This patient is suffering from prolonged ileus, which is not uncommon following major abdominal surgery for obstruction.
Continuing to feed nasogastrically (A) is not likely to be sucessful as there is still ileus.
Similarly NJ feeding (B) is unlikey to improve the situation as the ileus is distal to the jejunum. NJ feeding is an excellent choice for conditions involving an upper small bowel ileus, such as pancreatitis.
Percutaneous endoscopic gastrostomy (PEG)(D) is used in patients with a functioning gastrointestinal tract but with a complication of the upper tract, such as an unsafe swallow.
This patient is ideal for short term TPN (C) until he can be put back on to oral intake.
A patient is commenced on total parenteral nutrition. You are asked by the
nutrition team to ensure that adequate monitoring takes place. Which one of the following statements regarding monitoring of total parenteral nutrition is most correct?
A. Daily liver function tests
B. Weekly blood capillary glucose
C. Monthly full blood count
D. There is no need to monitor phosphate
E. None of the above
E. None of the above
with the patient undergoing TPN; Blood glucose should be monitored daily as disturbances in glucose are common.
It is common to have electrolyte disturbances so U&Es should be daily, hypophosphataemia is a particular issue.
Sepsis is another significant risk, so a FBC should be taken daily.
Daily weights are another monitoring requirement, as is careful fluid balance charting. LFTs need to be carried out twice weekly to montor for fatty infiltration and cholestatic jaundice.
