ABOHNS Sleep Medicine common mistakes
ABOHNS Sleep Medicine · Understand the traps and how to avoid them.
Assigning an AHI from a home sleep apnea test scored with a 3% desaturation criterion or a peripheral arterial tonometry device as if it were equivalent to a polysomnography AHI, then staging severity and qualifying for therapy on that number without noting the device type and scoring rule.
Candidates memorize the AHI cut points (5/15/30) as fixed thresholds and treat 'AHI' as a single interchangeable quantity, forgetting that HSAT underestimates AHI when it uses 4% desaturation, excludes hypopneas scored on arousal, and cannot detect events in supine-only or REM-only patterns because total sleep time is estimated rather than measured.
What to do instead
Always state the recording type, the hypopnea rule (recommended 3%-or-arousal vs 4%), and the denominator (TST on PSG vs recording time on HSAT) alongside any AHI. For HSAT, describe the result as a positive or negative study rather than a severity stage, and recommend in-lab PSG when the HSAT is negative but pretest probability is high.
Reading a PSG epoch and calling an event an apnea rather than a hypopnea (or vice versa) without applying the amplitude-reduction and desaturation/arousal criteria, and misassigning obstructive versus central based on the presence of snoring rather than on whether respiratory effort persists through the event.
Trainees learn apnea and hypopnea as a visual 'big drop' versus 'small drop' and use snoring or thoracoabdominal paradox as a shortcut for obstruction, when the defining discriminator for central events is absent inspiratory effort on the effort channels (or, on respiratory inductance plethysmography, in-phase motion with no airflow).
What to do instead
Score mechanically: apnea = ≥90% airflow reduction for ≥10 s; hypopnea = ≥30% reduction with ≥3% desaturation or an arousal; obstructive = continued or increasing effort; central = absent effort. When effort channels are unreliable, state that the event is unclassified rather than guessing.
Treating an elevated central apnea index on the diagnostic PSG as an independent primary diagnosis and proceeding to therapy selection without first looking for treatment-emergent central apnea on the titration study, opioid exposure, Cheyne-Stokes pattern with heart failure, or an underlying hypoventilation syndrome on the blood gas.
Central sleep apnea is taught as one bucket, so candidates anchor on the diagnostic-night central index and skip the stepwise exclusion that determines management (ASV for Cheyne-Stokes with HFrEF is contraindicated, treatment-emergent central apnea often resolves on CPAP, and hypoventilation requires bilevel with a backup rate rather than ASV).
What to do instead
For any central predominance, systematically document: awake PaCO2 or bicarbonate, LVEF and heart failure status, opioid and sedative use, presence of Cheyne-Stokes crescendo-decrescendo pattern, and the central index on the titration night. Let that matrix drive device selection instead of the diagnostic central index alone.
Choosing a surgical procedure for obstructive sleep apnea based on the site of collapse seen on awake endoscopy or Mueller maneuver alone, without drug-induced sleep endoscopy, airway imaging, or a documented CPAP trial and anatomic eligibility criteria (for example, offering upper airway stimulation without confirming hypoglossal nerve responsiveness and absence of complete concentric palatal collapse).
Candidates want a single anatomic answer and over-trust awake examination, which poorly predicts the collapsibility pattern during sleep; they also skip the payer and evidence requirements that make many sleep surgeries conditional on failed or intolerant PAP therapy.
What to do instead
Frame every surgical answer as a sequence: confirm OSA and severity, document PAP failure or intolerance, localize collapse with DISE (reporting level and VOTE pattern), then match the procedure to the pattern and to published selection criteria. Explicitly state when a procedure is not indicated because criteria are unmet.
Ordering or interpreting a multiple sleep latency test or maintenance of wakefulness test in a patient who is sleep-deprived, on REM-suppressing or alerting medications, or without a preceding adequate diagnostic PSG, and then diagnosing narcolepsy or idiopathic hypersomnia from a short mean sleep latency.
The MSLT is treated as a stand-alone test, but its validity depends on prior sleep sufficiency, medication washout, and a preceding PSG that excludes another cause of daytime sleepiness; candidates also forget that a mean sleep latency under 8 minutes with two or more sleep-onset REM periods supports narcolepsy type 1/2 only in the right clinical context, and that a single SOREMP can occur in the preceding PSG.
What to do instead
Before interpreting an MSLT or MWT, verify the preceding PSG showed adequate sleep, confirm sleep logs or actigraphy for at least a week, list medication washout intervals, and require the full criteria (mean sleep latency and SOREMP count plus cataplexy or hypocretin for narcolepsy type 1). State explicitly when the test is uninterpretable rather than diagnostic.
Managing chronic insomnia with hypnotic monotherapy or with sleep-hygiene advice alone, and omitting cognitive behavioral therapy for insomnia as first-line treatment, while also failing to screen for and treat the comorbid depression, anxiety, or substance use that maintains the insomnia.
Candidates default to pharmacologic answers because drug names are concrete and testable, and they treat sleep hygiene as equivalent to CBT-I; they also miss that insomnia is often secondary and that untreated comorbidity predicts relapse.
What to do instead
Make CBT-I the default first-line answer for chronic insomnia in adults, with pharmacotherapy as an adjunct or short-term option, and always pair the treatment plan with screening for and management of psychiatric and medical contributors. Reserve hypnotics for specific documented indications and note the dependence and fall-risk caveats in older adults.
Diagnosing a parasomnia from a bedpartner's report of 'acting out dreams' or 'sleepwalking' without polysomnography, and failing to distinguish REM sleep behavior disorder (loss of REM atonia, dream enactment) from non-REM arousal disorders (confusional arousals, sleep terrors, sleepwalking arising from slow-wave sleep) or from nocturnal seizures.
Parasomnia history is vivid and candidates accept it at face value, but the disorders differ in sleep stage of onset, age of onset, familial pattern, and prognosis, and RBD in particular warrants PSG with EMG and screening for synucleinopathy and for medication triggers such as SSRIs.
What to do instead
For any injurious or atypical parasomnia, obtain video-polysomnography with EMG to document the sleep stage of the event and the presence or absence of REM atonia. Classify by stage of origin, then address triggers (REM-suppressing or provoking drugs, sleep deprivation, alcohol) and screen for neurodegenerative disease when RBD is confirmed.
Applying adult obstructive sleep apnea criteria and adult AHI thresholds to a child, or recommending adenotonsillectomy as the answer for every pediatric sleep-disordered breathing case without considering age, adenotonsillar size, obesity, craniofacial features, or the option of watchful waiting in mild cases.
Adult and pediatric material are studied together, and the numeric thresholds, scoring rules (pediatric hypopnea requires 1% desaturation or arousal), and first-line management differ; candidates also forget that the pediatric PSG requires at least 8 hours of recording and that central apnea norms vary with age.
What to do instead
Use pediatric-specific scoring and interpretation rules: hypopnea with ≥1% desaturation or arousal, obstructive apnea-hypopnea index thresholds of 1 and 5 for mild and moderate-severe, and central apnea defined by duration and age. For management, base the recommendation on severity, adenotonsillar hypertrophy, obesity, and craniofacial risk, and state when observation or PAP or orthodontic intervention is preferable to surgery.
Clearing a patient for surgery or procedural sedation on the basis of a STOP-BANG score alone, or conversely cancelling a case for a high score, without integrating the score with the planned anesthesia, opioid requirement, and postoperative monitoring plan.
Screening tools are taught as diagnostic tests, so candidates treat an intermediate score as either a rule-out or an automatic contraindication; STOP-BANG is a screening instrument with limited specificity, and perioperative risk depends on the interaction of the score with the procedure and anesthetic plan.
What to do instead
Use the screening score to trigger a pathway, not a verdict: document the score, then specify the anesthetic strategy (regional where possible, limited opioids, careful extubation), postoperative monitoring level, and timing of a sleep evaluation. For known OSA, describe the plan for PAP continuation and escalation of monitoring rather than a blanket clearance or cancellation.
Missing the sleep disorder as the explanation for a comorbid presentation, such as attributing resistant hypertension, atrial fibrillation, refractory epilepsy, or treatment-resistant depression to medication failure without evaluating for and treating obstructive sleep apnea, or attributing daytime sleepiness in a heart failure patient to the heart failure alone without considering Cheyne-Stokes respiration and central sleep apnea.
Candidates compartmentalize by specialty and treat sleep as a separate domain, so they stop at the primary diagnosis and do not ask whether a treatable sleep disorder is driving or worsening it; they also underuse the bidirectional relationships that are heavily tested.
What to do instead
For resistant hypertension, atrial fibrillation, stroke, refractory epilepsy, and treatment-resistant depression, build OSA screening into the workup and state that treating OSA may improve the primary condition. For heart failure with nocturnal dyspnea or daytime somnolence, evaluate for central sleep apnea and Cheyne-Stokes respiration and note the ASV contraindication in HFrEF with predominant central apnea.