You assess a 55-year-old male patient who is a candidate for bariatric surgery. He is 175 cm, 120 kg and has arterial hypertension for which he takes ramipril. His wife tells you the patient snores during the night. His blood pressure (BP) is 125/75 mm Hg and pulse oximetry is 89% on room air.
What is the MOST appropriate management of this patient?
Correct Answer: B
In the above case, the patient has a STOP-Bang (1) score of at least 5 (snoring, hypertension, male gender, BMI, and age; no information is given on daytime tiredness, observed apneas, or neck circumference), identifying him as a high-risk patient for OSA. He also has medically controlled hypertension and resting hypoxemia. The Society for Anesthesia and Sleep Medicine guidelines (2, 3) recommend additional evaluation for preoperative cardiopulmonary optimization in patients who have a high probability of having OSA where there is indication of an additional problem with ventilation or gas exchange, as is the case of this patient (option B).
Considering the increased risk of postoperative complications and the potential optimization of the patient, it is unwise to proceed to elective surgery without further testing (option A). An arterial blood gas analysis would provide further information on gas exchange; however there is already indication of a high-risk patient with impaired gas exchange, so an arterial blood gas analysis would not be the most appropriate (option C). Initiation of PAP treatment (option D) is a likely step in the management of this patient; however, it is only to be started after confirmation of underlying OSA and only a part of the workup and preoperative optimization of the patient.
References :
A 65-year-old male with a history of heart failure and central sleep apnea with Cheyne-Stokes (CSA-CSB) breathing presents to your clinic for evaluation. He had been started on continuous positive airway pressure (CPAP) therapy but did not tolerate it. His recent echocardiogram shows an ejection fraction (EF) of 40%. His medical therapy has already been optimized.
Correct Answer: C
The optimal treatment of CSA-CSB in patients with an EF ≤45% who do not tolerate CPAP is uncertain. Although ASV use was recommended by the 2012 American Academy of Sleep Medicine (AASM) guidelines (1), a distinction was made in the 2016 update (2) between its use in patients with EF ≤45% (in whom it is contraindicated, option A is therefore wrong) and in patients with EF >45% (in whom it may be considered). Currently, the guidelines suggest initiation of supplemental nocturnal oxygen (option C). In the presence of an established diagnosis of CSA-CSB, another inlaboratory PSG is not indicated (option B). Finally, use of BPAP-ST is only indicated by the guidelines if there is no response to an adequate trial of CPAP and oxygen therapies (therefore option D is incorrect).
References:
You evaluate a 49-year-old patient who has been referred to you because of excessive daytime sleepiness. His past medical history includes drug-controlled hypertension, obesity (body mass index [BMI] 36 kg/m2 ), and low back pain for which he has been taking daily nonsteroidal anti-inflammatory drugs (NSAIDs) and oxycodone for the past 5 years. Upon questioning his wife reports loud snoring during the night, to the point where she has sometimes had to sleep in another room. She does not think she has witnessed any apneic episodes but states she cannot be certain.
What is the MOST appropriate next step in the management of this patient?
Correct Answer: A
The patient in the presented case has an increased risk of moderate to severe OSA, as he presents with excessive daytime sleepiness, loud snoring, and diagnosed hypertension. The AASM guidelines on diagnostic testing for adult OSA (1) recommend that prediction algorithms, diagnostic tools, and questionnaires (such as the Berlin Questionnaire, the STOP-Bang questionnaire, the Epworth Sleepiness Scale, etc) should not be used to diagnose OSA in adults in the absence of PSG or HSAT (therefore answer C is wrong). An uncomplicated patient is defined by the absence of (A) conditions that place the patient at increased risk of nonobstructive sleep–disordered breathing (including chronic use of opioid medication); (B) concern for significant nonrespiratory sleep disorder(s) that require evaluation or interfere with the accuracy of HSAT; (C) environmental or personal factors that preclude the adequate acquisition and interpretation of data from HSAT. The guidelines recommend either PSG or HSAT in uncomplicated patients at an increased risk of moderate to severe risk of OSA, and in case of patients who do not fit this definition of uncomplicated, the guidelines recommend PSG rather than HSAT (answer A is therefore correct; answer B is wrong). Overnight pulse oximetry does not provide enough clinical or laboratory information to formulate a diagnosis of OSA (option D is incorrect).
Reference:
You are asked to evaluate a 45-years-old female who is scheduled to undergo elective laparoscopic cholecystectomy. Her past medical history includes hypertension, which is controlled with an angiotensin-receptor blocker (ARB), and obesity (BMI 39 kg/m2 ). Upon questioning, she tells you she snores loudly during the night and often dozes off during the day. Investigating further, she reports she has been told she sometimes stops breathing during the night. Her vital signs during your examination are:
She presents you with a recent echocardiogram, which is unremarkable. You take an arterial blood gas, which shows:
In the presented case, the patient has a STOP-Bang (1) score of at least 5 (snoring, tiredness, hypertension, observed apneas, and BMI; no information is given on neck circumference), identifying her as a high-risk patient for OSA. Her vital signs and arterial blood gas are normal (no sign of resting hypoxemia or hypoventilation), and her recent echocardiogram shows no signs of pulmonary hypertension. The Society for Anesthesia and Sleep Medicine guidelines (2, 3) recommend that all perioperative providers, and the patient, are made aware of the high likelihood of OSA and its potential impact on morbidity and recommend proceeding to surgery without further testing provided: (A) there is no indication of uncontrolled systemic condition or additional problems with ventilation or gas exchange (hypoventilation syndromes, pulmonary hypertension, or resting hypoxemia), as in this case and (B) strategies for mitigation of postoperative complications are implemented (option B).
Considering the nature of the surgery (not major) and the stable conditions of the patient, immediate further testing is not necessary and is not a reason to delay surgery (option A). Initiation of PAP treatment in the absence of a confirmed diagnosis of OSA is incorrect, albeit it is a likely therapy the patient will undergo after her diagnostic workup (option C). A further echocardiogram, in the presence of a recent normal one, is unlikely to add any clinical information (option D).
A 43-year-old female is referred to your clinic by her primary care physician after undergoing a polysomnographic study, which supports a diagnosis of OSA (Apnea-Hypopnea Index [AHI] 25). Her BMI is 36 kg/m2 , her BP is 135/70, HR 82 bpm, and SpO2 88% on room air. She presents you with a recent arterial blood gas on room air (pH 7.35, pCO2 51 mm Hg, pO2 60 mm Hg, and HCO3 − 31 mEq/L), chest x-ray (which is reported as normal), and spirometry (showing a restrictive picture). She denies ever smoking or taking recreational drugs and only takes simvastatin for her high serum cholesterol levels (now under control).
What is the MOST likely diagnosis?
Correct Answer: D
OHS is defined as a combination of obesity (BMI >30 Kg/m2 ) and daytime hypercapnia (PaCO2 >45 mm Hg) in the absence of other causes that could account for awake hypoventilation, such as lung or neuromuscular disease. The patient in the presented case meets diagnostic criteria for both OSA (positive PSG with AHI 25) and OHS (PaCO2 51) (1, 2) (option D).
The patient’s spirometry showing a restrictive, rather than obstructive, picture and the absence of smoking history make the diagnosis of COPD unlikely (option A). Overlap syndrome is the combination of COPD and OSA and, for the same reason, is unlikely (option C). Finally, the patient has a clear laboratory diagnosis of OSA, as stated in the description, but option D is a more complete explanation of the clinical picture than option B.