2011.1 Flashcards
ME46 Acromegaly due to excess of growth hormone. Why is it difficult to do a direct laryngoscopy?
A: Distorted facial anatomy B: Macroglossia C: Glottic stenosis D: Prognathe mandible E: Arthritis of the neck
B. Macroglossia
Stoelting:
Management of anesthesia in patients with acromegaly is complicated by changes induced by excessive secretion of growth hormone. Particularly important are changes in the upper airway. Distorted facial anatomy may interfere with placement of an anesthesia face mask. Enlargement of the tongue and epiglottis predisposes to upper airway obstruction and interferes with visualization of the vocal cords by direct laryngoscopy. The distance between the lips and vocal cords is increased due to overgrowth of the mandible. The glottic opening may be narrowed, because of enlargement of the vocal cords. This, in addition to subglottic narrowing, may necessitate use of a tracheal tube with a smaller internal diameter than would be predicted based on the patient’s age and size. Nasal turbinate enlargement may preclude the passage of nasopharyngeal or nasotracheal airways. A preoperative history of dyspnea on exertion or the presence of hoarseness or stridor suggests involvement of the larynx by acromegaly. In this instance, indirect laryngoscopy may be indicated to quantitate the extent of vocal cord dysfunction. When difficulty placing a tracheal tube is anticipated, it may be prudent to consider an awake fiberoptic tracheal intubation.
Acromegaly associations:
Diabetes, hypertension, LVH, IHD, CCF, osteoarthritis, amenorrhoea
Airway:
- Macroglossia, prognathism, OSA, laryngeal tissue hypertrophy, reduced glottic opening
MZ82 Ehlers-Danlos syndrome. Most important to specifically do all EXCEPT:
A: Avoid hyperextension of the neck B: Damage to the teeth C: Avoid joint hypermobility D: Manage gastro oesophageal reflux E: Strict temperature regulation
?? D. Manage gastro-oesophageal reflux
Stoelting:
Ehlers-Danlos syndrome consists of a group of inherited connective tissue disorders caused by abnormal production of procollagen and collagen. It is estimated that 1 in 5000 people is affected by this syndrome. The only form of Ehlers-Danlos syndrome associated with an increased risk of death is the type IV (vascular) syndrome. This form may be complicated by rupture of large blood vessels or disruption of the bowel.
Signs and Symptoms:
All forms of Ehlers-Danlos syndrome cause signs and symptoms of joint hypermobility, skin fragility or hyperelasticity, bruising and scarring, musculoskeletal discomfort, and susceptibility to osteoarthritis. The gastrointestinal tract, uterus, and vasculature are particularly well endowed with type III collagen, which accounts for complications such as spontaneous rupture of the bowel, uterus, or major arteries. Premature labor and excessive bleeding at the time of delivery are common obstetric problems. Dilation of the trachea is often present, and the incidence of pneumothorax is increased. Mitral regurgitation and cardiac conduction abnormalities are occasionally seen. Patients may exhibit extensive ecchymoses with even minimal trauma, although a specific coagulation defect has not been identified.
Management of Anesthesia:
Management of anesthesia in patients with Ehlers-Danlos syndrome must consider the cardiovascular manifestations of this disease and the propensity of these patients to bleed excessively. Avoidance of intramuscular injections or instrumentation of the nose or esophagus is important in view of the bleeding tendency. Trauma during direct laryngoscopy must be minimized. The decision regarding placement of an arterial or central venous catheter must consider the fact that hematoma formation may be extensive. Extravasation of intravenous fluids resulting from a displaced venous cannula may go unnoticed because of the extreme laxity of the skin. Maintenance of low airway pressure during assisted or controlled mechanical ventilation seems prudent in view of the increased incidence of pneumothorax. There are no specific recommendations for the selection of drugs to provide anesthesia. Regional anesthesia is not recommended because of the tendency of these patients to bleed and form extensive hematomas. Surgical complications may include hemorrhage and postoperative wound dehiscence.
ET02 An 85y.o for open AAA repair. Refuses blood because of risk of vCJD. You tell him you won’t anaesthetise him as the risk is too high. This is an example of:
A: Autonomy B: Beneficence C: Malevolence D: Coercion E: Paternalism
E. Paternalism
Beneficence: refers to actions that promote the well being of others
Malevolence: evil, hostile
Coercion: to use threat or force to obtain compliance
Paternalism: philosophy that certain health decisions, eg, whether to undergo heroic surgery, appropriateness of care in terminally ill pts, are best left in the hands of those providing health care.
2009 Anaesthesia Blue Book:
In bioethics literature, paternalism is divided into two forms – weak and strong. Weak paternalism is making decisions believed to be in the patient’s best interest when the patient is incapable (incompetent) to do so. Strong paternalism is making a decision in the patient’s best interest, despite what a competent patient wishes.
MH61 A 35yr old African-American with sickle cell and fractured ankle for ORIF. Hb 90, Haematocrit 0.3.
A: Transfuse 2 units packed cells (?pre-op)
B: Let him cool passively to low/normal temperature
C: Spinal is safe
D: Avoid thiopentone
E: Tourniquet is absolutely contra-indicated
C. Spinal is safe
Anesthesiology 2004:
There is an argument for transfusing to dilute sickle cells but only suggested for moderate/high periop risk where Hb S is >30%. Definitely useful in ‘acute chest syndrome’. The generally accepted practice is to not use preoperative transfusion therapy in healthy hemoglobin SC patients, nor for limited minor surgery in stable hemoglobin SS patients.
Theoretical benefit in core cooling, e.g. bypass, but skin cooling associated with precipitating crises and low normothermia best.
Generally try to avoid use of a tourniquet, although not absolutely contraindicated (risk can be minimised by fully exsanguinating limb prior to inflating the tourniquet)
SN18 Absolute contraindication to sitting position for posterior fossa craniotomy for meningioma
A: Presence of patent ventriculo-atrial drain/shunt
B: PFO
C: Oesophageal stricture so transoesophageal echo placement is out
D: ?
E: ?
A. Presence of patent ventriculo-atrial drain/shunt
B. PFO
OHA:
Intra-cardiac septal defects are an absolute contraindication for sitting position. Absolute contraindications include cerebral ischaemia when awake and upright, and the presence of a patent ventriculo-atrial shunt or patent foramen ovale
- MC42 ANZCA version [2004-Apr] Q75, [Mar11]
Abnormal Q waves are NOT a feature of the ECG in
A. an old myocardial infarction B. left bundle branch block C. recent transmural myocardial infarction D. digitalis toxicity E. Wolff-Parkinson-White syndrome
D. Digitalis toxicity
- NEW(?) Coeliac plexus block. What is the complication?
A: Erectile dysfunction B: Constipation C: Hypertension which resolves spontaneously D: Paralysis E:
D. Paralysis
Coeliac plexus block
Indication: For relief of pain from non-pelvic intra-abdominal organs.
Complications:
• Severe hypotension may result, even after unilateral block.
• Bleeding due to aorta or inferior vena cava injury by the needle.
• Intravascular injection (should be prevented by checking the needle position with radio-opaque dye).
• Upper abdominal organ puncture with abscess/cyst formation.
• Paraplegia from injecting phenol into the arteries that supply the spinal cord (prevented by checking the needle position with radio-opaque dye) or secondary to intrathecal injection.
• Sexual dysfunction (injected solution spreads to the sympathetic chain bilaterally).
Intramuscular injection into the psoas muscle.
• Lumbar nerve root irritation (injected solution tracks backwards towards the lumbar plexus).
- NEW. Long stem about an old #NOF patient with aortic stenosis. What is a sign/ investigation/ symptom that shows the most severity? (ie Which one of these would indicate that the lesion was severe?)
A: Thrill in Aortic area B: Murmur in lower left sternal edge C: Murmur radiating to carotids D: History of ischaemic heart disease or coronary artery disease E: history of angina/ syncope
Alternate:
D: valve area = 1.2cm2
E: gradient = 30mmHg
A. Thrill in aortic area
E. History of angina/syncope
The ACC/AHA guidelines define ‘severity’ of AS as valve area 40mmHg, jet velocity>4m/2 – and even if the valve is ‘severe’ it does not necessarily necessitate replacement unless there are symptoms or reduced LVEF or the pt is hypotensive with an EST
CEACCP (2005):
Symptoms do not correlate well to the severity…
A typical finding is a carotid thrill and, in severe cases, a lag can be detected with simultaneous palpation between the apical impulse and the carotid thrill. A precordial thrill may be felt, especially on leaning forward in expiration. Its presence is reasonably specific for severe aortic stenosis.
- NEW. You get a TOE on a patient with aortic stenosis. What is the finding most likely to indicate that the valve needs replacement? possibly same as TMP-Jul10-010
A: Average pressure gradient 30mmHg
B: Valve area 1.2cm(squared)
C: dyspnoea
C. Dyspnoea
Patients with severe AS and low cardiac output often present with a relatively low transvalvular pressure gradient (i.e., mean gradient less than 30 mm Hg). Such patients can be difficult to distinguish from those with low cardiac output and only mild to moderate AS. In the former (true anatomically severe AS), the stenotic lesion contributes to an elevated afterload, decreased ejection fraction, and low stroke volume. In the latter, primary contractile dysfunction is responsible for the decreased ejection fraction and low stroke volume; the problem is further complicated by reduced valve opening forces that contribute to limited valve mobility and apparent stenosis.
- NEW. Petit mal epilepsy - Which is true? (or words to that effect)
A: Most common in child
B. Can precipitate seizures by hyperventilating
Peaks at 4-8 years
Hyperventilation provokes seizure
Usually short (
- NEW. (I know previous variants exist) Hypertension- severe- in pregnancy (or was it PET?) What NOT to use?
A: Hydralazine B: Nifedipine C: Labetalol D: Metoprolol E: SNP NB Magnesium was NOT an option
In a severe hypertensive emergency, when the above-mentioned medications (hydralazine, labetalol, nifedipine) have failed to lower BP, sodium nitroprusside may be given (Medscape)
If severe hypertension, metoprolol bad (rpt from 2010)
- NEW. Post CEA on ward, patient seizes. BP has been hard to control. What to do to prevent further seizures?
A: Add another antihypertensive B: Start antiplatelet drugs C: Start anticonvulsants D: Do angio and stent E: Nimodipine
A. Add another antihypertensive
Post-carotid hyperperfusion syndrome
- Often poor outcome
- Need control of BP, not seizures
- They do need urgent carotid Doppler and CT as well, but BP control is what will prevent further seizures
- NEW. Which have been shown to decrease vasospasm post aneurysm? All EXCEPT:
A: Antiplatelet drugs B: Nimodipine C: HHH therapy D: E:
A. Antiplatelet drugs
Limited evidence for ticlodipine or aspirin (cochrane says don’t use) but not for vasospasm per se (reduce platelet aggregation)
Nimodipine 60mg oral 4hourly for 21 days or 4mg/kg/day IV improves outcome, less cerebral infarction/ischaemia.
Possibly not due to reduced vasospasm (not proven to be). Decreases neural Ca.
- NEW. Post operative left pneumonectomy. What to do with underwater seal drain?
A: Nurse patient in R lateral decubitus position
B: Expect to see bubbles
C: Suction every hour for 5 minutes
D: Unclamp drain once an hour for 5 minutes, leave clamp on for the rest of the time
E: Leave on free drainage
D. Unclamp drain once an hour for 5 mins, leave clamp on for the rest of the time
Don’t want remaining lung dependent (fluid from thorax may enter stump) or non-dependent (herniation), supine best for first 2-3 days.
Suction = cardiac herniation = death
Bubbling = air leak
Fluid is meant to accumulate in the hemithorax so free drainage counterproductive.
- New? What is NOT true for PDPH following puncture
A: Prophylactic bed rest B: Catheter in intrathecally C: D: E:
A. Prophylactic bed rest
Postdural puncture headache (APMSE)
PDPH, usually following spinal anaesthesia, inadvertent dural puncture with an epidural needle, diagnostic or therapeutic lumbar puncture or neurosurgery, occurs with an incidence of approximately 0.7–50% (Bezov 2010a NR; Bezov 2010b NR). Up to 85% of cases improve spontaneously within 6 wk.
Risk factors are younger age, female gender, low BMI, history of prior PDPH and history of chronic headache.
- There is no evidence that bed rest or fluid supplementation are beneficial in the treatment and prevention of postdural puncture headache (S) (Level I [Cochrane Review]).
- Epidural blood patch administration is more effective than conservative treatment or a sham procedure in the treatment of postdural puncture headache (S) (Level I [Cochrane Review]).
- Morphine, cosyntropin and aminophylline are successful treatments for postdural puncture headache; dexamethasone is not, with inconclusive data for fentanyl, caffeine and indomethacin (N) (Level I [Cochrane Review]).
- The incidence of postdural puncture headache is reduced by using smaller-gauge spinal or non-cutting bevel needles or by orientating the cutting bevel parallel to the spinal sagittal plane (S) (Level I).
- IV theophylline, IV hydrocortisone, gabapentin and pregabalin are effective in the treatment of postdural puncture headache (N) (Level II).
Opioids should be used with extreme caution in the treatment of headache; pethidine should not be used (S).
Frequent use (>8–10 days/month) of analgesics, triptans and ergot derivatives in the treatment of recurrent acute headache may lead to medication overuse headache (U).
- Magnesium for treatment of pre-eclampsia. What is the therapeutic level? (I think this may be a repeat of an old question, but i remember two of the options were
A: B: 3 - 5 C: 5 - 7 D: E:
- 7-3.5
thewomens. org.au:
Serum magnesium concentrations should be checked every 6 hours in the antepartum and intrapartum phase (therapeutic level of magnesium: 1.7 to 3.5 mmol/L).
- NEW. Autonomic dysreflexia. Which ONE is true?
A: 50% of patients with a level below T6 B: Unlikely if below T10 C: Can be prevented?? D: Can be precipitated by light touch E. ?
B. Unlikely if below T10
emedicine:
Reported prevalence rates vary, but the generally accepted rate is 48-90% of all individuals who are injured at T6 and above. Some incidence has been reported in SCI as low as T10.
Unlikely with injury level below T10 is true.
- NEW. Ageing (adult) causes:
A: Decreased FRC
B: Decreased Cardiac output
C: Diastolic dysfunction
D: Increased creatinine
C. Diastolic dysfunction (best answer)
B. Decreased cardiac output
Journal of applied Physiology, Review: ageing and the CV system
Functional changes: In the resting aging heart, there are largely no alterations of systolic function, with preserved ejection fraction and stroke volume; because resting heart rate is unchanged or only minimally reduced with aging, cardiac output is also preserved (38).
Instead, diastolic function does undergo significant age-related changes, with a reduction in early diastolic filling compensated for by increased end-diastolic filling and a consequent progressive reduction of the echocardiographic early wave/atrial wave (E/A) velocity ratio (34).
Frca.co.uk:
Lung and chest wall compliance decrease with advancing age. Total lung capacity (TLC), Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV1) and Vital Capacity are all reduced as people age. Residual Volume (RV) increases and Functional Residual Capacity (FRC) remains unchanged. These changes occur as a result of reduction in elastic support of the airways and leads to increased collapsibility of alveoli and terminal conducting airways.
Cardiac output falls by 3% per decade which is due to reduced stroke volume and ventricular contractility.
In the elderly, decreased muscle bulk results in reduced creatinine production (but measured Cr is often artificially normal as GFR declines to progressive loss of renal cortical glomeruli).
- NEW. TEG tracing given, post cardiac surgery. Had quite slim tail (ie fibrinolysis) but broader ‘shoulders’.
A: Fibrinolysis B: Hypofibrinogenaemia C: Platelet dysfunction D: Heparin effect E: Surgical bleeding
A. Fibrinolysis
- NEW. Really poor copy of a CXR. Looked to me like a haemopneumothorax (you could very faintly see a collapsed lung outline, there was no ‘meniscus’ to the fluid shadow) but other people thought it was an artefact. It did indeed look like a pneumothorax and then someone had put a piece of metal up to simulate a haemothorax, because on the lateral you couldn’t see past the ribs (ie the film was cut off at the rib borders). It was terrible quality (too black, and hard to discern tissue from air), and an inadequate film (cut off apices, and poor lateral view as before)
A: Pneumothorax B: Haemopneumothorax C: D: E: Artefact.
B. Haemopneumothorax
- NEW? Post scoliosis repair, decreased movement bilaterally in the legs with decreased pain and temperature sensation but spared joint position sense and vibration. What is at fault?
A: Posterior spinal arteries B: Anterior spinal arteries C: Epidural haematoma D: Misplaced pedicle screw E: Lateral cord syndrome
B. Anterior spinal artery
(supplies the anterior 2/3 of the spinal cord - i.e. motor tracts and anterolateral/spinothalamic tracts)
dorsal column spared
Anterior spinal artery syndrome: The classic presentation: complete loss of strength below the level of injury; with a classic sensory pattern distal to the lesion, superficial pain and temperature discrimination are lost bilaterally with relative preservation of light touch, vibration, and position sense.
Lateral cord syndrome produces paresthesias and weakness on the side of the lesion and loss of pain and temperature on the opposite side. The unilateral involvement of descending autonomic fibers does not produce bladder symptoms.
- NEW. Anaesthetising an obese patient. Accelerometer on TOF 0.9. Could dose suxamethonium on ideal body weight or total body weight. With respect to 1mg/kg TBW vs. IBW you will see:
A: shorter onset and faster twitch recovery
B: shorter onset and similar twitch recovery
C: shorter onset and slower twitch recovery
D: similar speed of onset with similar speed of twitch recovery
E: similar onset and longer recovery
E. Similar onset, recovery (and better intubating conditions)
Lemmens, Anes Analg 2006 - The dose of succinylcholine in morbid obesity:
Optimal succinylcholine dosing for morbidly obese individuals (BMI > 40) was evaluated by randomized controlled trial with outcomes being onset of maximum neuromuscular blockade, intubating conditions, and duration of action of neuromuscular blockade. Groups received 1 mg/kg comparing dosing based on ideal body weight (IBW), lean body weight (LBW), or total body weight (TBW).
Results: Onset of neuromuscular blockade did not differ between groups. Intubating conditions were significantly better in the group dosed by TBW. Duration of action of neuromuscular blockade differed between groups, TBW > LBW > IBW.
Ingrande, BJA 2010 - Dose adjustments of anaesthetics in the morbidly obese:
In MO subjects, the amount of pseudocholinesterase is increased. In addition, the amount of extracellular fluid is increased. As both of these factors determine the duration of action of succinylcholine, administration should be based on TBW. When compared with administration based on 1 mg kg−1 IBW or LBW, 1 mg kg−1 TBW administration results in a more profound block and better tracheal intubating conditions, with clinically insignificant postoperative myalgia.
- NEW: The half-life of the active metabolite of levosimendan (OR-1896) is:
A: 1hr B: 8hr C: 24hr D: 3 days E: 7 days
D. 3 days
The pharmacokinetics of levosimendan are linear at the therapeutic dose range of 0.05-0.2 microg/kg/minute. The short half-life (about 1 hour) of the parent drug, levosimendan, enables fast onset of drug action, although the effects are long-lasting due to the active metabolite OR-1896, which has an elimination half-life of 70-80 hours in patients with heart failure (New York Heart Association functional class III-IV).
- NEW. When compared to a non-obese patient, in an obese patient (BMI >35) when fasted for an elective procedure, the gastric secretion will have:
A: more volume, higher pH B: more volume, lower pH C: same volume, same pH D: less volume, lower pH E: less volume, higher pH
C. Same volume, same pH
Anesth Analg. 1998 Jan;86(1):147-52.
A comparison of the volume and pH of gastric contents of obese and lean surgical patients. Previous studies have shown that obese surgical patients have a greater volume of acidic stomach contents than lean patients, despite a routine preoperative fast. We have reexamined this issue and found that among otherwise healthy, fasted, obese surgical patients, there is a lower incidence of combined high-volume, low-pH stomach contents compared with lean patients.
Anesth Analg. 2001 Dec;93(6):1621-2, table of contents.
Gastric residue is not more copious in obese patients IMPLICATIONS: Previous studies have shown that obese patients have a larger volume of gastric content than lean patients do. However, methodological limitations call into question the validity of these findings. We have reexamined this issue and found identical gastric content volumes in fasting obese and lean subjects after an 8-h fast.
ASA 2005
Gastric Volumes in Obese Patients Presenting for Day Case Surgery: No Need for Rapid Sequence Induction
Conclusion: The study revealed that fasted obese and non-obese patients presenting for day case surgery have similar volumes of gastric contents and that similar numbers of obese and non-obese patients have fasting gastric volumes >25ml at induction of anaesthesia.
Lots of references, most indicate that volume and pH are the same.
