QUIZ

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QUESTIONS

QUESTION 1
You have admitted a 23-year-old man with a head injury to the Intensive Care Unit. He has had a CT scan that shows some frontal contusion and diffuse cerebral oedema. He has a Glasgow Coma Score of 8 and is intubated.
The surgical registrar loudly asserts that evidence does not support the routine use of hyperventilation in head injury. A medical student attached to the ICU asks about this, as he has previously heard that both mannitol or hyperventilation are effective.
What will you tell him?

QUESTION 2
A 25-year-old man is brought in to hospital after falling from the top of a hay shed. He is conscious but complains that his chest is painful and he is having difficulty breathing. He obviously has a fracture of his left femur and both tibias. An iv is in situ and he has been given 500 ml Haemaccel and 500 ml N/saline on his way to hospital. He has an oxygen mask on at 15 l/min flow.

On examination he has a flail segment right chest with reduced breath sounds on the right. His heart rate is 140/min, BP 150/80, and respiratory rate 42/min. The pulse oximetry is not reading well, but intermittently there is a reading of 80% SpO2 .

 Arrangements have been made for him to be admitted to another hospital (because your hospital is on by-pass). The ambulance is ready to take the patient and the ambulance officers are keen to do so.
Do you feel he is fit to transfer?

QUESTION 3
A 15 year old boy presents with sudden onset of L) testicular pain whilst playing football. He is not sure if he was struck in the groin during play. The pain was initially severe but is resolving. He is nauseated but has not vomited. On examination his scrotum appears normal. The left testis is normal in size and position. It is moderately tender. The right testis is normal. You discuss the case with a fellow registrar who suggests getting a scrotal ultrasound to check for a traumatic haematoma. The ultrasound shows a normal testis with normal blood flow.

What is your management now?

QUESTION 4
You are asked to see a 78 year old woman who has been triaged as ‘gastroenteritis’. You note from the ambulance sheet that she has profuse ‘faeculant’ vomiting.

What should you be thinking as you go to see her?

QUESTION 5
A multigravid patient presents to the antenatal clinic at 24/40. She has recently moved from India and has had no antenatal care. The GP that referred her in to the clinic arranged antenatal bloods that are as follows:
A Neg
Anti-D titre 1/512
Hep B/C/HIV/RPR neg
Rubella immune
On examination, you notice that the symphysial-fundal height is 30cm.
(a) What test should be arranged immediately?
(b) An ultrasound confirms fetal hydrops with bilateral pleural effusions, ascites and polyhydramnios. What do you do next?
(c) Should other causes of fetal hydrops be considered?
(d) What risks are associated with intrauterine transfusion?
(e) Are ongoing transfusions likely to be necessary?
(f) Should this fetus be delivered?
(g) With what blood group should the fetus be transfused?

QUESTION 6
You review a patient in the antenatal clinic at 14/40. A routine RBC antibody screen is positive for anti-Kell antibodies.

(a) Are anti-Kell antibodies significant in pregnancy?
(b) What monitoring should be instituted?
(c) Are there any other RBC antibodies that are significant in pregnancy?





ANSWERS
Q1
The registrar is right. Routine hyperventilation is contraindicated and it is recommended that a PaCO2 of < 35 mmHg (4.66 kPa) is avoided during the first 24 hours after severe head injury.

MINI-TUTORIAL
Raised intracranial pressure can be rapidly reduced by acute hyperventilation, and this treatment been used routinely over the last 20 years. It is clear that cerebral blood flow following severe head injury is less than half of that in normal individuals, and that this falls further in the face of hyperventilation, with an increased risk of causing cerebral ischaemia.
Recent clinical studies have failed to show benefit, and on the contrary have been associated with adverse outcomes. Brief periods of hyperventilation may be necessary for acute neurological deterioration refractory to other treatment, but close monitoring for cerebral hypoxia is recommended when hyperventilation is employed.
    The use of hyperventilation in the management of severe traumatic brain injury.
    J. Neurotrauma 1996; 13: 699–703.
See Section 15.2 in Practical Intensive Care Medicine

Q.2.
No, he is certainly not fit to transfer. This is an important issue, which is often delegated to inexperienced staff. Perceived urgency often prevents considered thought.
Readiness to transfer needs to be considered in basic terms – airway, breathing, circulation.
His airway is satisfactory.
His breathing is unstable. He is hyperventilating. This may be due to thoracic problems or he may be hyperventilating to compensate formetabolic acidosis. In either case he is not stable.
He is also hypoxic (SpO2 80%). This is probably due to thoracic injury which requires investigation. He may require intubation and ventilation. An intercostal catheter may be indicated.
His circulation is unstable. He is inadequately resuscitated. His pulse rate is too high. Although the blood pressure is normal, this is not the most sensitive indicator of hypovolaemia. Where practical, demonstration of a postural drop is suggestive of hypovolaemia.
Poor peripheral perfusion is a common cause of failure of the pulse oximeter to function reliably.
He has fractures which can predictably be associated with at least 4 unit blood loss.
Thirst, urine output and low JVP may be other useful indicators of hypovolaemia.
His fractures have not been stabilised. Stabilisation is likely to reduce further blood loss, reduce the chance of fat embolism syndrome and minimise pain during transfer.
See Section 15.3 in Practical Intensive Care Medicine

Q.3.
This patient still requires urgent urology referral and possibly exploratory surgery to exclude testicular torsion. A normal ultrasound does not exclude this diagnosis. Most patients presenting with acute testicular pain should be discussed with a urologist. Testicular torsion is still the most likely cause of sudden testicular pain in this age group, and of course the most important to exclude. In this case it is possible the testis has torted transiently. The risk for further torsion remains and surgical exploration and orchidopexy may be indicated to prevent reoccurrence.
See Section 9.1 in Practical Emergency Medicine

Q. 4.
Faeculant vomiting (ie vomit that is offensive smelling, like faeces) indicates bacterial overgrowth in bowel content that has stagnated due to bowel obstruction. It is not at all characteristic of gastroenteritis.
When you see her you confirm the vomit is indeed offensive, her abdomen is distended and somewhat tender. An abdominal X-ray shows dilated small bowel with multiple fluid levels consistent with bowel obstruction. You refer her to the surgeons who subsequently operate on her and relieve an adhesion that was the cause of her obstructed bowel.
See Section 9.2 in Practical Emergency Medicine

Q. 5.
a) This fetus is at high risk of intrauterine haemolysis and the higher-than-expected fundal height raises the possibility of hydrops with polyhydramnios. An urgent ultrasound should be arranged.
b) This fetus will require blood sampling to confirm anaemia and intrauterine transfusion. This is performed in a tertiary center by an obstetrician specializing in ultrasound or a maternal fetal medicine specialist. Intrauterine transfusion carries a small risk of causing premature labour and this patient should be given corticosteroids to promote lung maturity in case of this occurring.
c) Yes. Although severe anaemia due to rhesus isoimmunisation is the most likely cause of this fetus’ cardiac failure, other caused of hydrops should be considered. These include cardiac abnormalities, chromosomal abnormalities, haematological abnormalities (such as thalassaemia) and intrauterine infections.
d) The risk of fetal loss with transfusion in a nonhydropic fetus is approximately 1%. However, for a fetus with established hdyrops this may be as high as 10-20% as these fetuses are less able to tolerate a significant volume load. The risks can be reduced by monitoring the umbilical vein pressure during the procedure and, in a fetus with hydrops, transfusing a smaller volume of blood in the first transfusion and repeating the transfusion in 24 to 48 hours.
e) Yes. This fetus will require ongoing transfusions. The second will usually be performed relatively soon after the first. Once the fetal haematocrit has stabilized, the frequency of transfusion will be decreased and are usually required two to four weekly.
f) No. The prognosis for a premature, hydropic neonate is poor. The aim of intrauterine transfusion is to deliver a non-anaemic fetus near term. Ideally, delivery is delayed until 37/40. However, if complications related to transfusion occur after 32/40, delivery may be considered. It is not advisable to continue the pregnancy beyond 37-38/40 as the placental permeability to antibodies increases after this time and this is associated with an increase in the level of haemolysis.
g) The fetus should be transfused with Rh negative blood that is compatible with the maternal blood. In this case A negative or O negative blood could be used.
See Section 4.8 in Practical Obstetrics
 
Q. 6.
a) Yes. Anti-Kell antibodies are associated with haemolytic disease of the newborn.
b) The titres should be monitored as for Rh isoimmunisation. Surveillance for fetal anaemia is undertaken with ultrasound, with or without fetal blood sampling. Amniocentesis and amniotic fluid spectography cannot be used with Kell isoimmuisation as the antibody affects red blood cell precursors as well as red blood cells. This means that the amount of bilirubin in the amniotic fluid (a marker of haemolysis) will underestimate the severity of the fetal anaemia.
c) Yes. There are many possible RBC antibodies, all directed at different proteins on the RBC surface. Some of these, such as Duffy (anti-Fy) and Kell (anti-K) are usually associated with intrauterine haemolysis. Others, such as anti Lewis antibodies (anti-L) are not.
See Section 4.9 in Practical Obstetrics