Week 15 Handout Flipped Classrooms: OSA

Question 1

What causes Obstructive Sleep Apnea (OSA)?

Answer 1

Decreased muscle tone in the upper airway during sleep leads to partial or complete obstruction, resulting in apneic episodes >10 seconds.

Question 2

What are the anatomical risk factors for OSA?

Answer 2

Obesity (↑ neck circumference >40 cm), hypopharyngeal tongue, temporomandibular distance >9 cm, caudally positioned larynx, large tongue mass.

Question 3

What is the prevalence of OSA in males and females?

Answer 3

Affects ~24% of males and ~9% of females.

Question 4

How many U.S. adults are estimated to remain undiagnosed with OSA?

Answer 4

Estimated 12–18 million U.S. adults remain undiagnosed.

Question 5

What does a STOP-BANG score of ≥3 suggest?

Answer 5

It suggests elevated risk of OSA.

Question 6

What are the co-morbidities associated with OSA?

Answer 6

Chronic hypoxemia and hypercapnia lead to atherosclerosis, hypertension, stroke, diabetes, dyslipidemia, heart failure, ischemic heart disease.

Question 7

How is OSA diagnosed?

Answer 7

Diagnosis is via polysomnography (sleep study) which measures the number of apnea/hypopnea episodes per hour (AHI).

Question 8

What are the AHI classifications for OSA severity?

Answer 8

Mild: 5–15/hr, Moderate: 15–30/hr, Severe: >30/hr.

Question 9

What is the gold standard treatment for OSA?

Answer 9

CPAP (Continuous Positive Airway Pressure).

Question 10

What are some perioperative considerations for OSA?

Answer 10

Evaluate comorbidities, ensure CPAP tolerance, patient education, and prefer non-opioid medications.

Question 11

What are the induction risks for patients with OSA?

Answer 11

May not ventilate post-induction; small doses of anesthetic can cause exaggerated effects.

Question 12

What are some difficult airway management techniques for OSA?

Answer 12

Ramp positioning, video laryngoscope, fiberoptic awake intubation.

Question 13

What are the anesthesia complications associated with OSA?

Answer 13

Difficult ventilation/intubation, increased risk with opioids, propofol, and neuromuscular blockers.

Question 14

What should be monitored in post-anesthesia care for OSA?

Answer 14

EtCO₂, pulse oximetry, ensure CPAP use post-op, and prolonged PACU stay if needed.

Question 15

What is the conclusion regarding OSA management?

Answer 15

OSA presents significant anesthetic risk; careful identification and monitoring are key to avoiding life-threatening complications.

Question 16

Screening: STOP-BANG Questions

Answer 16

Snore loudly?
Tired during the day?
Observed apneas?
Pressure (HTN)?
BMI > 35 kg/m²
Age > 50
Neck circumference >40 cm
Gender = Male

Question 17

Treatments for COPD

Answer 17

o CPAP (Gold standard)
o Weight loss
o Hypoglossal nerve stimulator
o Surgical removal of excess tissue
o Adjunctive analeptic drugs

Question 18

Student Question: Obstructive sleep apnea is defined as:
A. Tracheal obstruction due to increased oral secretions while sleeping

B. Episodes of 10 or more seconds where the patient holds breath when asleep

C. Breathing cessation for 10 or more seconds due to airway obstruction caused by relaxed pharyngeal musculature during sleep.

D. Nasal secretions obstruct airflow through the nasal cavity while sleeping

Answer 18

Answer: c. Sleep apnea is defined as the obstruction to breathing caused by the relaxation of pharyngeal musculature during sleep (Elisha et al., 2022).

Question 19

Student Question: Which of the following is NOT a positive criterion for the STOP BANG questionnaire?

A. Female patients are at a higher risk

B.Patients older than 50 are at higher risk

C. Patients with a neck circumference greater than 40 cm are at risk

D Patients with a BMI greater than 35 kg/𝑚2
are at risk

E.Patients who are tired during the day are at risk

Answer 19

Answer: a. The stop bang questionnaire assesses the patient for potential risk for sleep apnea. All of these, except for “a” are correct components for sleep apnea. The male gender is at higher risk for having sleep apnea (Butterworth et al., 2022)

Question 20

Student Question: Which co-morbidity is directly correlated with sleep apnea?

A. Lung cancer

B. Resistance to anesthetic agents

C. Bowel obstruction

D.Heart failure

Answer 20

Answer: d. Heart failure is directly correlated with sleep apnea. Other comorbidities related to sleep apnea include Atherosclerosis, hypertension/pulmonary HTN, stroke, diabetes, insulin resistance, dyslipidemia, and ischemic heart disease (Elisha et al., 2022).

Question 21

Student Question: A patient had an overnight polysomnography test assessing for OSA. The patient had an average of 26 abnormal respiratory events per hour of sleep. What is the patient’s risk for sleep apnea?

A. No risk
B. Mild
C. Moderate
D. Severe

Answer 21

Answer: c. The patient has a moderate risk for sleep apnea. No risk would be less than 5 incidents per hour, mild would be 5-15 incidents per hour, moderate is 15-30 incidents per hour, and severe is greater than 30 incidents per hour (Elisha et al., 2022).

Question 22

Student Question: A patient presents to an ambulatory surgery center for an ACL repair. After performing the STOP BANG assessment, the patient is positively screened for obstructive sleep apnea. On further assessment, the patient also has a history of atrial fibrillation (a-fib). When a 12-lead ECG is checked, the patient is currently in a-fib with a rate of 108, but their blood pressure is 120/80. How should the surgery team proceed?

A. Cancel the surgery; the patient is not in any condition for an elective procedure.

B. Reschedule the surgery; the patient has active co-morbidities associated with sleep apnea and is not appropriate for an outpatient procedure.

C. Cautiously perform the procedure, ensuring that video laryngoscopy is in the operating room and difficult airway precautions are observed.

D. Perform the surgery as scheduled; there is no contraindication for elective surgeries with sleep apnea, and the blood pressure is stable.

Answer 22

Answer: b. While elective surgeries are not contraindicated by obstructive sleep apnea, a patient with uncontrolled co-morbidities would not be an appropriate candidate for ambulatory surgery. The patient would benefit from a formal diagnosis and surgery at an in-patient setting (Butterworth et al., 2022, Figure 44-1).

Question 23

Student Question: Which is not an appropriate action taken by the CRNA during the anesthesia care of a patient with obstructive sleep apnea?

A. Ensure a patient with a history of OSA brings their home CPAP.

B. Have a video laryngoscope in the operating room before induction.

C. Ramp the patient’s upper body to optimize the intubating position.

D. Elect for an awake extubation

E. Utilize long-acting analgesics and anesthetics to optimize pain control and sedation.

Answer 23

Answer: e. Rather than utilizing long-acting anesthetics and analgesics that could increase the patient’s risk for post-op airway obstruction, the CRNA should utilize short-acting anesthetics and analgesics. The CRNA should assess the feasibility of regional anesthesia and non-opioid analgesics. Extubation when the patient is awake decreases the risk of airway obstruction after extubation (Elisha et al., 2022).

Question 24

What is Chronic Obstructive Pulmonary Disease (COPD)?

Answer 24

A progressive lung disease characterized by increasing breathlessness.

Question 25

What should be assessed in a preoperative assessment for COPD?

Answer 25

Disease severity, including recent exacerbations, cough, sputum production, and dyspnea.

Question 26

What tools are used to classify the severity of COPD?

Answer 26

GOLD Classification and BODE Index.

Question 27

What does the BODE Index include?

Answer 27

BMI, Obstruction, Dyspnea, and Exercise capacity.

Question 28

What is associated with lower BODE scores?

Answer 28

Better postoperative survival rates.

Question 29

What is associated with higher BODE scores?

Answer 29

Increased mortality.

Question 30

How can lung function be optimized preoperatively?

Answer 30

Through pre-op bronchodilator therapy and delaying elective surgery during acute exacerbations.

Question 31

What is a concern regarding neuraxial anesthesia in COPD patients?

Answer 31

High thoracic spinals/epidurals can restrict accessory muscle use and increase dyspnea and anxiety.

Question 32

Why should nitrous oxide be avoided in COPD patients?

Answer 32

It can expand bullae, increasing the risk of rupture and pneumothorax.

Question 33

What should be done cautiously with volatile agents?

Answer 33

They may impair mucociliary clearance and contribute to post-op atelectasis.

Question 34

What is a risk associated with opioid use in COPD patients?

Answer 34

Respiratory depression and V/Q mismatch.

Question 35

What are the ventilation management goals for COPD patients?

Answer 35

Low tidal volumes, avoid high peak inspiratory pressures, and use PEEP cautiously.

Question 36

What should be done to prevent air trapping during ventilation?

Answer 36

Use longer expiratory times and avoid high respiratory rates.

Question 37

What are recruitment maneuvers used for?

Answer 37

To help resolve atelectasis but should be used cautiously to prevent barotrauma.

Question 38

What may be required postoperatively for COPD patients?

Answer 38

Continued intubation and mechanical ventilation, especially after thoracic or upper abdominal surgery.

Question 39

What should CRNAs assume for OSA patients?

Answer 39

Difficult airway until proven otherwise.

Question 40

What should be monitored closely post-op for OSA patients?

Answer 40

Bring home CPAP.

Question 41

What should be avoided for COPD patients during anesthesia?

Answer 41

Nitrous oxide and high spinal/epidural levels.

Question 42

What should be focused on for COPD patients in the postoperative period?

Answer 42

Air-trapping prevention, ventilation strategy, and post-op pulmonary hygiene.

Question 43

What should be evaluated for asthma control before surgery?

Answer 43

Frequent inhaler use, recent ER visits or hospitalizations in the last 30 days, nocturnal awakenings with dyspnea, recent increases in medication requirements, signs of upper respiratory tract infection.

Question 44

When should elective surgery be postponed in asthma patients?

Answer 44

If the patient is actively wheezing or has signs of infection.

Question 45

What is the goal during intraoperative management of asthma?

Answer 45

Prevent airway reactivity and bronchospasm.

Question 46

What should be continued for preoperative optimization in asthma patients?

Answer 46

Bronchodilators (albuterol/ipratropium) and anxiolysis to reduce stress-induced bronchospasm.

Question 47

What are preferred induction agents for asthma patients?

Answer 47

Propofol, Ketamine, Sevoflurane.

Question 48

What should be avoided as induction agents in asthma patients?

Answer 48

Desflurane, isoflurane, Morphine, Atracurium, Mivacurium, non-selective beta blockers, Prostaglandins, and Ergonovine.

Question 49

What are the ventilation risks in asthma patients?

Answer 49

Air trapping, hyperinflation leading to decreased venous return and cardiac output, and risk of pneumothorax.

Question 50

What are lung-protective strategies during ventilation?

Answer 50

Use low tidal volumes, allow sufficient expiratory time, and avoid high airway pressures.

Question 51

What is the emergence strategy for asthma patients?

Answer 51

Consider deep extubation and use Sugammadex for reversal.

Question 52

What should be continued for pulmonary hypertension (PH) patients preoperatively?

Answer 52

All PAH medications (e.g., sildenafil, prostacyclin analogs).

Question 53

What assessments should be done for pulmonary hypertension patients?

Answer 53

ECG for RV strain, Echo for RV size/function and PAP, ABG, and Chest X-ray.

Question 54

What are the primary goals in intraoperative management of pulmonary hypertension?

Answer 54

Avoid increased pulmonary vascular resistance (PVR) and decreased systemic vascular resistance (SVR).

Question 55

What should be avoided in pulmonary hypertension patients?

Answer 55

Hypoxemia, hypercarbia, acidosis, hypothermia, pain, Ketamine, Nitrous oxide, and Desflurane.

Question 56

What is the preferred induction agent for pulmonary hypertension patients?

Answer 56

Etomidate for induction due to minimal cardiac depression.

Question 57

What is the first line treatment for hypotension in pulmonary hypertension patients?

Answer 57

Norepinephrine.

Question 58

What are early signs of acute pulmonary embolism (PE)?

Answer 58

Tachycardia, sudden decrease in ETCO₂ waveform and value, moderate hypoxemia without CO₂ retention.

Question 59

What are advanced signs of acute pulmonary embolism (PE)?

Answer 59

Hypotension, rapid rise in PAP and CVP, ECG changes.

Question 60

What should be done for intraoperative management of PE?

Answer 60

Secure airway, provide 100% FiO₂, support circulatory volume, and manage ventricular dysrhythmias.

Question 61

What are some causes of bronchospasm?

Answer 61

Airway Manipulation (e.g. Laryngoscopy, Endotracheal intubation, Extubation), Surgical Stress (particularly in patients with asthma or reactive airways), Allergic Reactions (medications, latex, antibiotics, or transfusion-related), Histamine-Releasing Agents (morphine, atracurium, mivacurium)

Question 62

What are the signs and symptoms of bronchospasm?

Answer 62

Auscultation: Diffuse wheezing (may be absent if airflow is minimal), Ventilator Changes: Increased peak inspiratory pressure (PIP), Decreased tidal volumes on volume-controlled ventilation, Capnography: Shark-fin ETCO₂ waveform → indicative of obstructive flow, Hypoxemia: Desaturation despite oxygen delivery, Increased mucous production: Can further worsen airway obstruction

Question 63

What is the first step in the treatment approach for bronchospasm?

Answer 63

Deepen Anesthesia to reduce airway stimulation and reactivity: Sevoflurane (volatile agent of choice – bronchial smooth muscle relaxation), Propofol, Ketamine (only IV agent with bronchodilatory properties), IV Lidocaine (1–1.5 mg/kg) may reduce airway reflexes

Question 64

What is the second step in the treatment approach for bronchospasm?

Answer 64

Increase FiO₂ by delivering 100% oxygen immediately to maximize alveolar oxygenation

Question 65

What is the third step in the treatment approach for bronchospasm?

Answer 65

Administer Beta-2 Agonists, such as a short-acting inhaled beta-agonist (e.g., albuterol)

Question 66

What is the fourth step in the treatment approach for bronchospasm?

Answer 66

Epinephrine for moderate to severe bronchospasm, especially if progressing toward anaphylaxis: IV Epinephrine: 10 mcg/kg boluses or Subcutaneous Epinephrine

Question 67

What is the fifth step in the treatment approach for bronchospasm?

Answer 67

Corticosteroids: Administer IV steroids to reduce inflammation and prevent recurrence, such as Methylprednisolone & Dexamethasone

Question 68

What are post-bronchospasm considerations?

Answer 68

Delay extubation until airway reactivity has subsided, ensure complete resolution of wheezing, monitor for recurrence in PACU, may need post-op bronchodilator therapy or ICU monitoring

Question 69

Why is neuraxial anesthesia above T6 avoided primarily in COPD patients? A) Potential for increase in functional residual capacity and reduced preload B) Potential for decrease in respiratory drive and anxiety C) Potential for decreases in expiratory residual capacity and restriction of accessory muscle use D) Potential for vasodilation and decreased cardiac output

Answer 69

Correct Answer: C) Decreases ERV and restricts accessory muscle use Rationale: High spinal or epidural blocks can impair the use of accessory muscles needed for breathing, especially in COPD patients. While neuraxial anesthesia can cause vasodilation and decreased cardiac output, this is not the primary concern.

Question 70

What is the most appropriate intraoperative management strategy for a patient with pulmonary hypertension undergoing surgery? A) Use nitrous oxide for anesthesia B) Aggressively lower blood pressure with propofol C) Avoid hypoxemia, hypercarbia, and acidosis D) Administration of ketamine for induction

Answer 70

Correct Answer: C) Avoid hypoxemia, hypercarbia, and acidosis Rationale: These conditions increase pulmonary vascular resistance and can worsen pulmonary hypertension and right heart strain. Use of nitrous oxide is not recommended as it impairs the delivery of higher levels of FiO2 and can increase pulmonary vascular resistance (PVR). Use of ketamine is not recommended as it can also increase PVR.

Question 71

What is a common early sign of pulmonary embolism during general anesthesia? A) Bradycardia and hypoventilation B) Decreasing end-tidal CO₂ and tachycardia C) Sudden fever and hypertension D) Sudden, unexplainable respiratory alkalosis

Answer 71

Correct Answer: B) Decreasing end-tidal CO₂ and tachycardia Rationale: A sudden drop in PETCO₂ with tachycardia is a key early sign of a PE, due to impaired pulmonary perfusion and gas exchange. Patients would not be hypertensive, but rather hypotensive, hypoxic, with high PaCO2.

Question 72

What ventilator management strategy is most appropriate for a COPD or Asthmatic patient to reduce air trapping during surgery? A) Increase respiratory rate and PEEP B) Use a 1:1 I:E ratio C) Increase tidal volume D) Prolong expiratory time (e.g., I:E ratio of 1:3 or 1:4)

Answer 72

Correct Answer: D) Prolong expiratory time (e.g., I:E ratio of 1:3 or 1:4) Rationale: COPD and symptomatic asthmatic patients benefit from longer expiratory times to prevent dynamic hyperinflation and air trapping. Increasing tidal volumes and levels of PEEP can lead to pneumothorax in patients with air trapping. Normal I:E ratio is 1:2, patients with air trapping need a prolonged expiratory phase in order to allow optimum exhalation of volumes.

Question 73

Which of the following anesthetic agents should be avoided in patients with pulmonary hypertension due to its effect on increasing pulmonary vascular resistance (PVR)? A) Etomidate B) All barbiturates C) Ketamine D) Nitric Oxide

Answer 73

Correct Answer: C) Ketamine Rationale: Ketamine increases pulmonary vascular resistance and should be avoided in patients with pulmonary hypertension to prevent right ventricular strain or failure. Barbiturates are not specifically mentioned in the text in regard to their effect on PVR. Nitric Oxide causes a vasodilation of the pulmonary vasculature and is a useful took in the treatment of pulmonary hypertension. Etomidate has little effect on hemodynamics and is considered a great choice for a cardio-stable induction medication.

Question 74

During a routine surgical case, the nurse anesthetist identifies a “shark fin” sign on ETCO2 waveform and the sudden increase of inspiratory pressures on the ventilator. Upon auscultating the patient, the anesthetist hears wheezing and decreased air movement. What should the nurse anesthetist suspect and what should their next steps be? A) Flash pulmonary edema; administer high FiO2 and diuretics B) Laryngospasm; Deepen level of anesthesia and administer a neuromuscular blocker to prevent negative pressure pulmonary edema. C) Bronchospasm; Deepen level of anesthesia and administer a short-acting beta2 agonist D) Pulmonary Embolism; Increase FiO2 to 100%, stop anesthetic agent, and treat hypotension.

Answer 74

Correct Answer: C) Bronchospasm; Deepen level of anesthesia and administer a short-acting beta2 agonist Rationale: Air trapping, increase in inspiratory pressures, wheezing, and decreased air movement are all signs of a bronchospasm, but a laryngospasm. Pulmonary edema and pulmonary embolism can simulate a bronchospasm.