2. 90. A 66-year-old man with severe chronic
obstructive airways disease presents for a
laparoscopic hernia repair as a day case.
Which is the most appropriate anaesthetic agent to
use in this patient?
A Bupivacaine
B Desflurane
C Sevoflurane
D Remifentanil
E Lidocaine
3. 90. C Sevoflurane
Laparoscopic hernia repairs are most frequently done under
general anaesthetic, although there a few reports of regional
anaesthetic techniques being used but this is not common
practice. General anaesthesia is required to ensure optimal
ventilation, avoidance of excessive build-up of CO2 and
abdominal discomfort despite adequate regional blockade.
Therefore, lidocaine and bupivacaine would not be ideal agents
in this patient. Under general anaesthesia, the ideal agent in this
patient would be sevoflurane because it provides bronchodilator
properties that would be of benefit to patients with chronic
obstructive airways disease (COAD). Desflurane is irritative to
airways and can precipitate bronchospasm, particularly in
patients with COAD.
4. In which of the following patients would the
administration of PEEP be
expected to improve oxygenation during OLV?
A. A 68-year-old man with severe emphysema on
tiotropium undergoing lobectomy
B. A 34-year-old man with α1 antitrypsin deficiency
undergoing wedge resection
C. A 51-year-old woman with moderate COPD on
pulmonary function tests (PFTs) undergoing pleurectomy
for mesothelioma
D. A 42-year-old woman with interstitial lung disease
undergoing VAT wedge resection
5. 43. A 76-year-old woman with a history of COPD
presents for preoperative evaluation before
shoulder surgery. Which of the following tests is
best able to identify CO2 retention?
A. PFTs showing improvement in symptoms with
bronchodilators
B. PFTs showing a decreased diffusion capacity
C. Arterial blood gas
D. Exercise tolerance
6. 44. A 68-year-old man with a history of severe COPD presents for urgent
exploratory laparotomy for small bowel obstruction. A room air arterial blood
gas reveals a PaO2 of 51 mm Hg, and brief history reveals noncompliance with
prescribed oxygen therapy. On induction of anesthesia, the CVP rises from 14
to 26 mm Hg, and the patient becomes progressively hypotensive. Airway
pressures are normal, ECG shows sinus bradycardia, and oxygen saturation is
>90%. Which of the following is the most likely mechanism of this patient’s
hypotension?
A. Right ventricular dysfunction
B. Tension pneumothorax
C. Acute blood loss
D. Severe bronchospasm
7. 19. Correct answer: D
Patients with severe obstructive lung disease often
have large emphysematous changes that involve
alveolar destruction and large dilated airspaces.
Increased PEEP only serves to distend these
damaged airspaces further and is not usually
helpful in isolated obstructive disease. Conversely,
in fibrotic lung disease there may be a component
of recruitable lung and it is reasonable to trial some
PEEP to improve oxygenation.
8. 43. Correct answer: C
Although severe COPD often shares multiple characteristics, including reversibility
with bronchodilators, decreased diffusion with emphysema, and poor exercise
tolerance, not all of these are required. Carbon dioxide retention, a characteristic of
severe obstructive disease, can only be diagnosed on arterial blood gas, showing an
elevated partial pressure of carbon dioxide and metabolic compensation.
Knowledge of chronic retention is critical because it allows for the provider to
minimize the changes of overventilating the patient and causing a subsequent severe
respiratory alkalosis. Worsening carbon dioxide retention also may imply an acute
exacerbation, which would necessitate postponing elective surgery to allow for
better optimization.
9. 44. Correct answer: A
Patients with severe COPD who develop chronic hypoxia are at high risk to
develop pulmonary hypertension. Home oxygen therapy is often prescribed
to reduce the
progression of pulmonary hypertension. This therapy is usually appreciated
by the
patients, as it improves exercise tolerance; however, it is critical that the
anesthesia
provider is aware of the utility in reducing the progression of pulmonary
hypertension. In this noncompliant patient, the acute vital sign changes are
concerning for impending right ventricular collapse, which is often
exacerbated by the induction of general anesthesia, particularly in the patient
in whom the pulmonary hypertension is unexpected. These patients will
benefit from an anesthetic strategy that minimizes interruptions in
ventilation, avoids acidosis, avoids hypoxia, and maintains coronary perfusion
because of the sensitivity of the right ventricle. Patients with severe enough
disease may warrant additional invasive monitoring such as transesophageal
echocardiography and/or pulmonary artery catheterization.
