Obstructive Sleep Apnea
OSA High-yield Verified · Sep 2026Obstructive sleep apnea is repeated complete (apnea) or partial (hypopnea) collapse of the upper airway during sleep, causing oxygen desaturation or arousal from sleep and fragmented, nonrestorative sleep. It differs from central sleep apnea, in which the brain fails to drive breathing.
Snoring, witnessed pauses and daytime sleepiness in an older, heavier man; why the diagnosis needs a sleep study and an AHI; CPAP as the mainstay and adherence as its weak point; side-sleeping and no alcohol or sedatives at night; and the post-operative nurse’s concern — opioids and sedation in a patient whose airway already closes in sleep.
What’s going wrong in the body
The normal physiology, where it fails, and why the body’s compensation backfires.
01 Why the airway closes only in sleep
"Obstructive sleep apnea (OSA) is characterized by episodes of complete (apnea) or partial (hypopnea) collapse of the upper airway, leading to decreased oxygen desaturation or arousal from sleep." "This disruption results in fragmented and nonrestorative sleep." Awake, muscle tone holds the airway open; asleep, it does not: "During sleep, there is decreased tonic activity of the laryngeal, supraglottic, oropharyngeal, nasopharyngeal, and lingual musculature, which results in dynamic collapse with respiration." That "results in a dynamic decrease in the caliber of the upper airway and therefore increased resistance to airflow."
A crowded airway collapses first. "Anatomical factors that promote pharyngeal narrowing include a large neck circumference, excess soft tissue, bony structures, or blood vessels." "Upper airway patency decreases with increased soft tissue mass within a given confined space within the craniofacial skeleton," and "People with obesity can have increased fat deposits in their neck that can block their upper airway." Inspiration itself pulls the walls in: "Upper airway obstruction during sleep is often caused by negative collapsing pressure during inspiration."
Obstructive versus central. "Obstructive sleep apnea is caused by conditions that block airflow through your upper airway during sleep. For example, your tongue may fall backward and block your airway." "Central sleep apnea is caused by problems with the way your brain controls your breathing while you sleep." On a sleep study the difference is effort — an apnea is obstructive "If an increased effort is present throughout the entire apnea" and central "If no effort is detected throughout the entire apnea."
02 Every event costs oxygen and sleep — and, over years, the heart
The collapse ranges "to complete airway obstruction, decreased oxygenation, and frequent arousals throughout sleep." NHLBI: "It can cause low oxygen levels during sleep and prevent you from getting enough quality sleep. Also, it takes a lot of effort to restart breathing many times during sleep, and this can damage your organs and blood vessels." The broken sleep shows by day: "Excessive daytime sleepiness is one of the most common symptoms."
The downstream list is long. "Multiple large studies have demonstrated that patients with moderate to severe OSA are at increased risk for coronary artery disease, systemic hypertension, cardiac arrhythmias, congestive heart failure, pulmonary hypertension, right heart failure, and cerebrovascular accident." "Patients with OSA are involved in motor vehicle collisions at a rate of 2 to 3 times that of the general population." "There is also a two to threefold increase in non-alcoholic fatty liver disease incidence in patients with OSA independent of obesity." "However, untreated OSA can be life-threatening."
It is common. "In the United States, it has been reported that 25% to 30% of men and 9% to 17% of women meet the criteria for OSA," and "OSA affects almost 1 billion people globally." "OSA in adults is most commonly associated with obesity, male sex, and advancing age"; after 50, "as many women as men develop the disorder."
03 Treatment splints the airway open — if the patient uses it
CPAP is the mainstay. "CPAP maintains airway patency by increasing upstream pressure (ie, nasal pressure), thereby preventing collapse during both inspiration and expiration." "Continuous positive airway pressure (CPAP) is the most effective treatment for adults with OSA," and "Positive airway pressure is the initial treatment for nearly all patients with OSA and remains the mainstay of treatment." It brings "improved sleep quality, reduction or elimination of snoring, and decreased daytime sleepiness," and "CPAP can also alleviate pulmonary hypertension and reduce blood pressure."
Hard outcomes remain uncertain — keep the hedge. "Although CPAP is an effective temporary treatment for OSA, it does not reduce the risk of cardiac complications." "However, treatments have not been shown to decrease mortality, cardiovascular events, and neurocognitive function in the long term." StatPearls reports "conflicting findings when assessing the effect of CPAP therapy on cardiovascular outcomes." And adherence is the weak point: "nearly half of patients do not consistently follow treatment after the first month."
Other layers. Weight loss "can often decrease the severity of OSA," but "it is usually not curative." Side-sleeping helps when OSA "is more pronounced in the supine position." Oral appliances advance the lower jaw for patients "who are unable or unwilling to use CPAP," and hypoglossal nerve stimulation works "by stimulating the genioglossus muscle (an upper airway dilator) during apneas." Surgery "is considered a last resort." In December 2024 the FDA "approved Zepbound (tirzepatide) for the treatment of moderate to severe obstructive sleep apnea (OSA) in adults with obesity, to be used in combination with a reduced-calorie diet and increased physical activity"; "The improvement in AHI in participants with OSA is likely related to body weight reduction with Zepbound." It "should not be used in patients with a personal or family history of medullary thyroid cancer or in patients with Multiple Endocrine Neoplasia syndrome type 2."
Causes & risk factors
Modifiable factors are teaching targets — the patient can act on them.
Signs & symptoms
Each finding tied to the mechanism that produces it — and the triage it calls for.
Diagnostics
Complications
Medications for this condition
Why each class is prescribed here — every card links to its full pharmacology page.
Caution — avoid where possible and monitor closely. StatPearls lists opiates among the drugs that "may exacerbate their condition." With PCA, sleep apnea raises the risk of "decreased level of consciousness, respiratory distress, and hypotension"; continuous pulse oximetry, end-tidal CO2 monitoring and frequent vital signs "may be required," especially at initiation.
Caution. On StatPearls’ avoid list; "Use of sedatives and hypnotics" is a risk factor. If a sedative is used in hospital to help CPAP tolerance, "close monitoring is critical, as sedatives or anxiolytics can decrease consciousness and respiratory drive." NHS: do not take sleeping pills "unless recommended by a doctor – they can make sleep apnoea worse."
Tell the team before surgery or sedation. "Your provider may have to take extra steps to make sure that your airway stays open during the surgery and that the pain medicine doesn’t make it harder for your airway to stay open."
Beyond medications
- Positive airway pressure — the mainstay. CPAP "provides constant air pressure through your mouth and/or nose"; APAP "automatically adjusts the air pressure you receive during sleep"; BPAP "delivers different pressure based on whether you are inhaling or exhaling" and is "better tolerated by patients who require higher pressure settings (>15 cm H2O)." "It is important to use your PAP machine for all sleep, including naps." "If you are traveling, bring your breathing device with you."
- Making CPAP tolerable. Side effects include "congestion, a runny nose, dry mouth, or nosebleeds, with humidification often alleviating these symptoms." "Using the correct size mask and adequate padding can help prevent pressure sores." A ramp "initiates airflow at a lower level and gradually increases it to the prescribed pressure." Patients can wear the mask for part of the day, "such as while watching TV, to get used to how it feels."
- Cleaning and follow-up. "The mask and tubing should be cleaned regularly, inspected, and replaced every 3 to 6 months." "Clean your mask and wash your face before you put on the mask. This can help make a better seal between the mask and your skin." Regular checkups confirm the therapy is working ("you will need to schedule regular checkups to make sure that your treatment is working"); a repeat sleep study may be needed "especially if you gain or lose a lot of weight."
- Lifestyle. "The importance of weight loss should be emphasized in patients with OSA who are overweight or have obesity," though it "is usually not curative." Sleep on the side — NHS suggests "taping a tennis ball to the back of your sleepwear." Avoid alcohol, "especially shortly before going to sleep"; get "at least 7 to 8 hours of sleep each night"; NHLBI adds "limiting alcohol and caffeine intake, and quitting smoking."
- Alternatives. Oral appliances suit those "who are unable or unwilling to use CPAP" and are "typically most effective for candidates with appropriate dentition and mild-to-moderate sleep apnea"; they can cause "dental pain, occlusal changes, temporomandibular joint disease, dry mouth, bruxism, and gingival irritation." Hypoglossal nerve stimulation is for moderate-to-severe OSA with CPAP intolerance; its commonest adverse events are "tongue abrasion (11.0%), pain (6.2%), and device malfunction (3% to 6%)." Surgery "does not cure the disorder, is expensive, and may lead to severe complications." Nasal obstruction is treated "with nasal steroids for allergic rhinitis or surgically for nasal valve collapse."
- Tirzepatide (Zepbound) — the first FDA-approved medicine for OSA, for moderate to severe OSA "in adults with obesity," with diet and activity. It works by "activating receptors of hormones secreted from the intestine (glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)) to reduce appetite and food intake." "This medicine is injected under the skin." Its warnings include "pulmonary aspiration during general anesthesia or deep sedation," so patients should tell providers about planned surgeries.
Nursing considerations
The RN-specific layer — each action paired with the reason it matters.
How a real nurse thinks
The clinical-judgment loop, worked for a typical presentation — reasoning, not reference.
- 1 Recognize cues
Within an hour of starting a PCA, a patient with known OSA is drowsy, has a slow respiratory rate with witnessed pauses, low oxygen saturation and a falling blood pressure. Sleep apnea is a named risk for PCA complications — "decreased level of consciousness, respiratory distress, and hypotension" — and complications are most likely at initiation. His drowsiness is the early cue: "Respiratory depression is usually preceded by sedation."
- 2 Analyze cues
The opioid is adding to an airway that already collapses in sleep. StatPearls advises patients with OSA to avoid opiates because they "may exacerbate their condition." Decreased consciousness with hypoventilation is clinical deterioration, not ordinary post-operative sleepiness.
- 3 Prioritize
This is an emergency — escalate now. Stay with him and call the provider or rapid response team immediately. Open RN: "If a patient develops opioid-induced respiratory depression, the opioid is reversed with naloxone (Narcan) that immediately reverses all analgesic effect" — anticipate that order and a change in the analgesic plan.
- 4 Generate solutions
Anticipate continuous pulse oximetry and end-tidal CO2 monitoring with frequent vital signs, a review of the opioid plan, and orders about his CPAP. If he deteriorates, "Mechanical ventilation should be considered if signs of clinical deterioration are evident."
- 5 Take action
SBAR: 64-year-old man, POD 0 knee replacement, known OSA on home CPAP, BMI 38. Morphine PCA started at 2200. Now drowsy, rouses to voice then drifts off, RR 8 with witnessed apneas, SpO2 86%, BP 104/62. I am concerned about opioid-related respiratory depression. I am staying with him and need you at the bedside now, with orders for monitoring and his analgesia.
- 6 Evaluate
With the team at the bedside and orders carried out, he becomes easier to rouse, his respiratory rate and oxygen saturation improve, and he is placed on continuous oximetry and end-tidal CO2 monitoring. His analgesic plan is revised and CPAP use is ordered for sleep. The nurse documents the event and reinforces that he must tell every future care team about his sleep apnea.
Scenario — you’re the nurse
Work each question before revealing the answer. Rationales explain the wrong options too.
A 64-year-old man had a total knee replacement today. He has obesity, hypertension and obstructive sleep apnea treated with CPAP at home, which the nurse notes in the admission history. A morphine PCA was started at 2200. At 2300 he is drowsy and snoring loudly, with pauses in his breathing; he rouses to his name and falls back asleep mid-sentence.
Q1 Select all that apply Which findings in this patient require immediate escalation? Select all that apply. - A. Drowsy and falling asleep mid-sentence one hour after starting a PCA
- B. Respiratory rate 8 with witnessed pauses
- C. SpO2 86% on room air
- D. Snoring noted in the admission history
- E. Blood pressure falling from 138/84 to 104/62
Reveal answer & rationale
Q2 Multiple choice Which monitoring does Open RN say may be required when a PCA is started in a patient with sleep apnea? - A. Spot-check vital signs every 4 hours
- B. Continuous pulse oximetry, end-tidal carbon dioxide monitoring and frequent vital signs
- C. Daily arterial blood gases
- D. Neurological checks every shift
Reveal answer & rationale
Q3 Select all that apply Which statements by a patient newly started on CPAP show correct understanding? Select all that apply. - A. ‘I will use it whenever I sleep, including naps.’
- B. ‘If my stomach feels bloated, I should stop using it and call my provider.’
- C. ‘Once I lose weight, my sleep apnea will be cured.’
- D. ‘A humidifier can help if my mouth is dry.’
- E. ‘I will clean my mask and wash my face before putting it on.’
Reveal answer & rationale
Q4 Multiple choice A sleep study shows an AHI of 34 events per hour. How is this classified? - A. Normal
- B. Mild OSA
- C. Moderate OSA
- D. Severe OSA
Reveal answer & rationale
Q5 Multiple choice Which advice should the nurse give a patient with untreated OSA and daytime sleepiness? - A. Take a sleeping pill to improve night-time sleep
- B. Have a drink before bed to relax
- C. Do not drive if you feel tired or sleepy
- D. Sleep flat on your back
Reveal answer & rationale
Common questions
What causes obstructive sleep apnea?
Which findings should a nurse report immediately in obstructive sleep apnea?
Which medications are used to treat obstructive sleep apnea?
Does CPAP prevent heart attacks and strokes?
Why do nurses worry about opioids in patients with sleep apnea?
Is snoring the same as sleep apnea?
Sources
- Obstructive Sleep Apnea — StatPearls — StatPearls (NCBI Bookshelf)
- Sleep Apnea Syndrome — StatPearls — StatPearls (NCBI Bookshelf)
- Continuous Positive Airway Pressure — StatPearls — StatPearls (NCBI Bookshelf)
- Sleep Apnea — Causes and Risk Factors — NHLBI — National Heart, Lung, and Blood Institute (NIH)
- Nursing Fundamentals — Chapter 11 Comfort (Open RN; CC BY 4.0) — Open RN / Chippewa Valley Technical College (CC BY 4.0)
- Sleep Apnea — Treatment — NHLBI — National Heart, Lung, and Blood Institute (NIH)
- Sleep Apnea — Living With — NHLBI — National Heart, Lung, and Blood Institute (NIH)
- Sleep apnoea — NHS. Contains public sector information licensed under the Open Government Licence v3.0 (https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/) — NHS (Open Government Licence v3.0)
- FDA Approves First Medication for Obstructive Sleep Apnea (December 20, 2024) — U.S. Food and Drug Administration
- Initiate IV Therapy (patient-controlled analgesia) — Nursing Advanced Skills, Ch. 1 — Open RN / Chippewa Valley Technical College (NCBI Bookshelf)
Reviewed by Hae Suk Lee, RN
Educational summary for nursing students. Scenarios are fictional teaching cases. Always verify against current guidelines and your institution's protocols before acting in practice. Not medical advice.