Trauma/clinical physiology Flashcards
25845 – In an adult patient with haemorrhagic shock
1: systolic blood pressure of 60 mm suggests more than 1.5 litres blood loss
2: an isolated closed femoral fracture is unlikely to be the cause of a fall in systolic blood pressure
3: urine output is a useful sign of tissue perfusion
4: an acute 1 litre blood loss requires 3-4 litres of crystalloid for resuscitation
TFTT
12818, 21283 – The usual urinary nitrogen loss following trauma is further increased when
1: the patient has adrenal insufficiency
2: parenteral sources of nitrogen are provided
3: the patient is chronically ill and debilitated before trauma
4: the patient has a fever
FTFT
The urinary loss of nitrogen in trauma is the result of the stress-induced protein catabolism and muscle breakdown of amino acids. As cortisol is a catabolic hormone, in adrenal insufficiency catabolism nitrogen loss in the urine is reduced (A false). Moreover, when protein stores and muscle bulk are depleted in chronic illness, further catabolism associated with trauma is minimal (C false). However, when extraparenteral sources of nitrogen are provided, amino acid in excess is secreted in the urine, increasing the urinary nitrogen content (B true). Urinary nitrogen loss is increased in the febrile patient due to raised catabolism (D true).
25710 – A 15-year-old back seat passenger restrained by a lap-only seat belt in a car involved in a road traffic crash
A. is likely to suffer a lumbar spine compression fracture
B. would have hypotension as a likely early consequence of intra-abdominal bowel injury
C. should have a diagnostic peritoneal lavage if pancreatic injury is suspected
D. with an elevated plasma or peritoneal lavage amylase almost certainly has a pancreatic injury
E. should have a lumbar spine x-ray looking for a Chance hyper-flexion fracture
E
27844 – Concerning renal trauma
1: general resuscitation measures are the first priority in any multi-trauma case
2: CT scan is the imaging modality of choice in the acute phase
3: surgical exploration is required for all cases of renal trauma requiring blood transfusion
4: hypertension can occur in the long term after conservative management of renal trauma
5: the flank approach is ideal for isolated renal injuries
6: penetrating renal injuries almost invariably require exploration
TTFTFT
1 True. Remember your A B Cs (as per EMST).
CT scanning allows assessment of renal perfusion; the presence and function of the contralateral kidney; the extent, if any, of perirenal haematoma; and the presence or absence of urinary extravasation (2 True). If CT scans are not available intravenous pyelography may be used but this study is inadequate in 20% of cases. In the presence of continued or severe haemorrhage, arteriography may be helpful to elucidate the site of arterial bleeding and the presence or absence of arteriovenous malformation. Surgical exploration and repair or nephrectomy may be necessary in the presence of continued severe haemorrhage. Patients who respond to blood transfusion and remain stable do not necessarily require exploration. Surgery will more often be required for assessment and treatment of other intraabdominal injuries include damage to spleen, duodenum and bowel (3 False).
Causes of hypertension include:
* The ‘Page’ kidney with increased pressure due to a chronic subcapsular haematoma causing release of renin.
* Renal artery stenosis/thrombosis.
* A-V fistula (4 True).
Approach should be from a midline vertical laparotomy incision to obtain best exposure and vascular control when dealing with renal trauma (5 False). Penetrating renal trauma (bullets and stab injury) will commonly be associated with injuries to other intra-abdominal and thoracic viscera. Surgical exploration will almost invariably be necessary to repair other structures and to perform drainage. High powered shotgun injuries will be associated with more widespread tissue destruction and necrosis requiring, at times, extensive debridement and drainage (6 True).
25825 – A 63-year-old man becomes hypotensive six hours after a procedure to realign a fractured pelvis. An epidural is in place and running. Blood pressure is 80 mmHg and peripheries are cool. Management should include
1: administering oxygen and checking airway and breathing
2: administration of 500 ml colloid over two hours
3: checking the drains for bleeding
4: checking if the pulse is over 60 per minute as this will exclude the epidural as a cause of hypotension
TTTF
25698 – In a trauma patient with a crush pelvic fracture, a large retroperitoneal haematoma and shock
A. complete anuria would imply lower urinary tract obstruction until proved otherwise
B. low urine output precludes the use of contrast for radiological studies
C. renal dose dopamine, diuretics and mannitol are useful first line of treatment agents to prevent the development of renal failure
D. myoglobinuria secondary to rhabdomyolysis is unlikely to occur in the first 12 hours after injury
E. hyperkalaemia > 6 mMoI/I with ECG signs of toxicity would be an indication for immediate treatment with ion exchange resins (eg. resonium)
A
18237 – A previously fit 55 year old man has undergone an emergency right hemicolectomy for a perforated caecal carcinoma. On review 24 hours after the operation you note the following on his fluid balance sheet -
intravenous input 2L, nasogastric aspirate 2L, drain losses 700 ml, urine output 500 ml.
Biochemistry shows Na+ 135 mmol/L, K+ 3.0 mmol/L, Cl- 100 mmol/L, HC03- 27 mmol/L.
Which of the fluid balance regimens below
would you order for the next 24 hr period?
A. 2L N. saline + 3L dextrose 5% + 50 mmol KCl
B. 2L N. saline + 1L dextrose 5% + 50 mmol KCl
C. 1L N. saline + 3L dextrose 5% + 100 mmol KCl
D. 3L N. saline + 2L dextrose 5% + 100 mmol KCl
E. 1L N. saline + 1L dextrose 5% + 100 mmol KCl
D
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He has a total of 3200 ml sensible loss in the previous 24 hours, compared to a 2000 ml intake; and his urine output has only been 500 ml in that 24 hours. He is hypokalaemic. He is likely to be ‘saline’ depleted; and should have 5000 ml of fluid ordered in the next 24 hours to allow for this, with additional saline for ECF losses and both basal and additional potassium intake. D is thus the bestcombination.
18292 – A 58-year-old man is admitted for elective surgery for a carcinoma of the gastric antrum. On admission, it is found that he has been taking aspirin 100 mg daily for the past five years. What should be done?
A. Proceed to surgery forthwith
B. Give vitamin k 10 gm intravenously with the premedication
C. Give protamine sulphate with the premedication
D. Stop aspirin and delay surgery for one week
E. Halve dose of aspirin and delay surgery for one week
D
The excess bleeding risk from prolonged aspirin medication will take upwards of a week to reverse; so D is the correct response in this patient preparing for major excisional surgery.
25850 – You are presented with an obese 50-year-old man due on the afternoon list for repair of a right inguinal hernia. He complains of central chest pain which has lasted for one hour and is not subsiding. He has a history of indigestion. He has smoked 20 cigarettes daily for over ten years.
1: you delay the surgery, inform the anaesthetist and request an ECG
2: a normal ECG in this case definitely exclude a myocardial infarction
3: there is a high risk of reinfarction and death if this patient has an acute myocardial infarct, and surgery proceeds
4: this risk is eliminated if surgery is performed under local anaesthesia
TFTF
25820 – Concerning commonly prescribed cardiovascular drugs
1: antihypertensives should be omitted on the morning of the surgery
2: diuretics can cause hypokalaemia
3: diuretics can cause hyperkalaemia
4: Beta-blockers may cause impaired responses to hypovolaemia
TTFT
7309 – Prior to elective surgery a patient with myeloproliferative disorder is found to have a platelet count of 65,000 per cubic millimetre
1: surgery should proceed under cover of platelet concentrates
2: surgery should not proceed because the patient may have antibodies to blood platelets
3: a bleeding time estimation may be helpful to assess the degree of platelet dysfunction
4: platelet increments assessed by platelet count at say 10 minutes and 24 hours after infusion of blood platelets may be helpful to determine management
5: if platelet increments are known to be satisfactory, platelet concentrates need be given only if bleeding during surgery is excessive
FTTTT
25810 – A 75-year-old patient becomes shocked on the surgical ward the night after left nephrectomy. A subclavian CVP line is inserted and the reading is 18 cm H20. This may be
1: due to fluid overload or congestive cardiac failure (CCF)
2: a result of pulmonary embolism
3: a temporary elevation following a rapid fluid bolus
4: artefactual due to the line passing upward into the neck
TTTT
7297 – In the pre-operative assessment it is important to do which of the following?
1: Perform a routine INR, APTT and /or platelet count on all patients
2: Obtain a personal and family history of bleeding and bruising, particularly with dental extractions and operative procedures; if positive perform platelet count, INR and APTT and complete blood examination
3: Referral to a haematologist for special tests of haemostasis may be indicated even if the INR and APTT are normal
4: If the patient has been taking aspirin, perform INR, APTT and platelet count
5: If the APTT is 43 seconds (normal range 23-35 seconds) surgery should be postponed until the cause of the prolonged clotting time is determined
FTTFT
25815 – Patients at highest cardiac risk during non-cardiac surgery include those with
1: myocardial infarction less than six months ago
2: unstable angina
3: severe aortic stenosis
4: decompensated heart failure
TTTT
18343 – A 37-year-old patient is noted to be difficult to rouse one hour after a subcutaneous injection of 12.5 mg morphine. Her respiratory rate is 16 breaths/min. Which one of the following statements is most correct?
A. No immediate action is required but the amount of morphine she is given next time should be reduced
B. She does not have respiratory depression
C. She may have respiratory depression and should be given supplemental oxygen and 1000 μg naloxone iv prn
D. She may have respiratory depression and should be given supplemental oxygen and 100 μg naloxone iv prn
E. She should be given supplemental oxygen and nalorphine
D
Respiratory depression from opiate is the most likely diagnosis in this patient with a Sedation Score of 3. She requires supplemental oxygen to treat potential hypoxia; and naloxone intravenously as the specific morphine antagonist, in a starting dose of 100 micrograms intravenously to observe the initial effect (D).
