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Sleep-Disordered Breathing

Last updated 1 Jun 2026 · Pain & analgesia

📋 Key Information Summary

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  • Sleep-disordered breathing (SDB), particularly obstructive sleep apnoea (OSA), significantly increases perioperative risk through opioid-related respiratory depression, upper airway obstruction, and impaired arousal responses.
  • All surgical patients should be screened for undiagnosed OSA using the STOP-BANG questionnaire at pre-admission assessment.
  • Patients with moderate-to-severe OSA (AHI ≥ 15) are more sensitive to opioids and sedatives; lower starting doses and slower titration are mandatory.
  • Multimodal opioid-sparing analgesia — combining paracetamol, NSAIDs/COX-2 inhibitors, regional anaesthesia, gabapentinoids, and low-dose ketamine — is the standard of care for SDB patients.
  • Continuous postoperative monitoring with pulse oximetry and capnography (where available) is essential for the first 24–48 hours in patients with moderate-to-severe OSA receiving opioids.
  • Combining opioids with benzodiazepines, gabapentinoids at high doses, antihistamines, or other CNS depressants markedly increases the risk of life-threatening respiratory depression.
  • Patients using home continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) must bring their device to hospital and use it perioperatively, including in the post-anaesthesia care unit.
  • Regional and neuraxial anaesthesia techniques should be prioritised wherever feasible to minimise systemic opioid requirements.
  • Patients with OSA undergoing ambulatory surgery require extended observation (minimum 3 hours post-last opioid dose) and must meet strict discharge criteria including stable SpO₂ on room air.
  • Elevated STOP-BANG score (≥ 5) combined with opioid use warrants postoperative HDU/ICU-level monitoring.
  • Aboriginal and Torres Strait Islander Australians experience disproportionately higher rates of SDB due to obesity, chronic disease burden, and limited access to sleep medicine services in rural and remote areas.
  • Patient and family education on SDB risks, opioid dangers, and the importance of CPAP adherence is a critical component of the perioperative safety bundle.

Introduction & Australian Epidemiology

Sleep-disordered breathing (SDB) encompasses a spectrum of conditions characterised by recurrent episodes of partial or complete upper airway obstruction during sleep. Obstructive sleep apnoea (OSA) is the most prevalent form, defined by repetitive pharyngeal collapse causing apnoeic and hypopnoeic episodes with resultant oxyhaemoglobin desaturation, sleep fragmentation, and sympathetic activation. The perioperative period represents a time of heightened vulnerability for patients with SDB, as the depressant effects of anaesthetic agents, opioids, and sedatives compound the inherent physiological instability of the upper airway during sleep.

In Australia, population-based studies estimate that moderate-to-severe OSA (apnoea–hypopnoea index [AHI] ≥ 15 events/hour) affects approximately 10–14% of the adult male population and 4–6% of adult females, with rates substantially higher in middle-aged and older adults. The Sleep Health Foundation Australia estimates that up to 80% of moderate-to-severe OSA cases remain undiagnosed. This represents a major patient safety concern, as many individuals presenting for surgery carry unrecognised OSA that places them at elevated risk of perioperative adverse events.

Anaesthetic deaths attributable to postoperative respiratory depression in undiagnosed OSA have been the subject of coronial inquests across multiple Australian states and territories. The Australian and New Zealand College of Anaesthetists (ANZCA) and the Australian Commission on Safety and Quality in Health Care (ACSQHC) have identified OSA screening and perioperative management as a key patient safety priority. The ACSQHC Standard 8 (Recognising and Responding to Acute Deterioration) is directly relevant, mandating appropriate monitoring and escalation pathways for at-risk patients.

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Undiagnosed OSA is a leading contributor to preventable postoperative respiratory events. Routine preoperative screening should be considered for all surgical patients, particularly those with obesity (BMI ≥ 30 kg/m²), neck circumference > 43 cm (males) or > 38 cm (females), and comorbid cardiovascular or metabolic disease.

The intersection of SDB and pain management is of particular clinical importance. Pain itself fragments sleep architecture, worsening SDB severity, while the pharmacological agents used to treat pain — principally opioids — depress central respiratory drive and reduce pharyngeal muscle tone, creating a vicious cycle of airway obstruction, hypoxaemia, and hypercapnia. This article addresses the evidence-based approach to perioperative analgesia in patients with SDB, including screening, opioid-sparing strategies, monitoring requirements, and the dangers of sedative co-administration.

OSA Risk — Screening, Classification & Perioperative Implications

STOP-BANG Screening

The STOP-BANG questionnaire is the most widely validated and recommended tool for preoperative OSA screening in the surgical population. It comprises eight binary (yes/no) items, each scoring 0 or 1, yielding a total score of 0–8:

Item Criteria
S — SnoringLoud snoring (audible through closed doors)
T — TiredDaytime tiredness/fatigue/sleepiness
O — ObservedObserved episodes of apnoea or choking during sleep
P — PressureTreatment for hypertension (or diagnosed hypertension)
B — BMIBMI > 35 kg/m²
A — AgeAge > 50 years
N — NeckNeck circumference > 40 cm
G — GenderMale sex

Risk Stratification by STOP-BANG Score

Low Risk
STOP-BANG 0–2
Low probability of moderate-to-severe OSA. Standard perioperative analgesia and monitoring protocols apply.
Setting: Standard ward care
Intermediate Risk
STOP-BANG 3–4
Intermediate probability of OSA. Consider further evaluation with home sleep study or in-lab polysomnography. Implement enhanced monitoring and opioid-sparing analgesia if OSA confirmed.
Setting: Enhanced observation, telemetry consideration
High Risk
STOP-BANG 5–8
High probability of moderate-to-severe OSA. Treat as OSA positive. Mandatory opioid-sparing strategies, HDU/ICU monitoring, CPAP continuation, and anaesthetic consultation.
Setting: HDU / ICU postoperatively

Pathophysiology of Perioperative Risk in OSA

Patients with OSA have a fundamentally altered respiratory physiology that is destabilised by anaesthesia and opioid therapy:

  • Reduced pharyngeal muscle tone: General anaesthesia and opioids relax the genioglossus and palatal muscles, exacerbating the baseline tendency to pharyngeal collapse.
  • Impaired arousal response: Opioids and sedatives blunt the ventilatory arousal mechanism — the reflexive awakening that restores airway patency during obstructive episodes. In OSA patients, this arousal threshold may already be elevated.
  • Central respiratory depression: Opioids suppress the medullary respiratory centre, reducing both respiratory rate and tidal volume. This effect is amplified by concurrent hypoxaemia from upper airway obstruction.
  • Decreased FRC and atelectasis: Postoperative supine positioning, abdominal/thoracic surgery, and residual neuromuscular blockade reduce functional residual capacity (FRC), lowering oxygen stores and accelerating desaturation during apnoeic events.
  • Fragmented sleep architecture: Pain, noise, light, and nursing observations in hospital disrupt normal sleep cycling, increasing the proportion of REM sleep on the second and third postoperative nights — a period associated with maximal OSA severity and respiratory instability.
  • Fluid redistribution: Perioperative fluid administration causes rostral redistribution of fluid from the legs to the neck during recumbency, further narrowing the pharyngeal airway.

Obesity Hypoventilation Syndrome (OHS)

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Critical distinction: Obesity hypoventilation syndrome (OHS) — defined as BMI ≥ 30 kg/m² with chronic daytime hypercapnia (PaCO₂ > 45 mmHg) not attributable to other causes — carries significantly higher perioperative risk than uncomplicated OSA. Patients with OHS require arterial blood gas analysis preoperatively, HDU/ICU admission postoperatively, and extreme caution with all respiratory depressants. OHS affects an estimated 0.3–0.6% of the Australian obese population and is frequently unrecognised.

Investigations

Essential STOP-BANG questionnaire Applied to all surgical patients at pre-admission clinic. MBS item 104 (initial specialist consultation if referral to sleep medicine).
Available Home sleep study (respiratory polygraphy) Validated for screening and diagnosis in moderate-to-high pre-test probability patients. Available through public and private sleep laboratories. MBS item 12203 (Level B — overnight respiratory study).
Specialist In-laboratory polysomnography (PSG) Gold standard for OSA diagnosis and severity grading. MBS item 12210 (Level C — comprehensive polysomnography). Indicated when home study is inconclusive or comorbid central sleep apnoea/narcolepsy suspected.
Available Arterial blood gas (ABG) Essential in all patients with suspected OHS (BMI ≥ 30, raised serum bicarbonate ≥ 27 mmol/L, or clinical features of hypoventilation). Baseline PaCO₂ guides postoperative monitoring intensity.
Available Echocardiography Consider in patients with long-standing untreated OSA to assess for pulmonary hypertension and right ventricular dysfunction (cor pulmonale). MBS item 55118.

Opioid-Sparing Multimodal Analgesia

Opioid-sparing (or opioid-minimising) analgesia is the cornerstone of safe pain management in patients with SDB. The goal is to achieve adequate analgesia while minimising opioid dose and duration. Current Australian and international guidelines recommend a multimodal approach combining two or more non-opioid analgesic agents with regional or neuraxial techniques, reserving opioids for breakthrough or refractory pain at the lowest effective dose.

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Principle: Every opioid-sparing strategy that reduces total opioid consumption translates to measurable reductions in postoperative respiratory adverse events in OSA patients. Aim for ≥ 50% reduction in morphine-equivalent consumption compared to opioid-centric regimens.

First-Line Non-Opioid Analgesics

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Paracetamol (Acetaminophen)
Panadol® · Panamax® · Analgesic / antipyretic
Adult dose (oral) 1 g PO QID (max 4 g/day); 6-hourly interval
Adult dose (IV) 1 g IV QID (max 4 g/day); perioperative loading
Paediatric dose 15 mg/kg PO/IV QID (max 60 mg/kg/day in children < 12 years; 4 g/day in children ≥ 12 years)
Renal adjustment eGFR 10–50: increase interval to Q8H; eGFR < 10: Q12H. Max 2 g/day in severe hepatic impairment.
Duration Continue regularly for 48–72 hours postoperatively, then PRN
PBS status ✔ PBS General Benefit
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Ibuprofen
Nurofen® · Brufen® · NSAID
Adult dose 200–400 mg PO TDS–QID with food (max 2.4 g/day for acute pain)
Paediatric dose 5–10 mg/kg PO TDS (max 30 mg/kg/day; for children ≥ 3 months)
Renal adjustment Avoid if eGFR < 30. Use with caution eGFR 30–60. Ensure adequate hydration.
Key safety note NSAIDs do NOT depress respiratory drive. Excellent opioid-sparing agent. Avoid in active GI bleeding, severe renal impairment, or perioperative coronary artery bypass grafting.
PBS status ✔ PBS General Benefit
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Celecoxib
Celebrex® · Selective COX-2 inhibitor
Adult dose 400 mg PO stat (pre-emptive), then 200 mg PO BD for 3–5 days
Paediatric dose Not routinely used < 18 years for acute pain (limited data)
Renal adjustment Avoid if eGFR < 30. Reduce dose 50% if eGFR 30–60.
Advantage COX-2 selective — lower GI bleeding risk than non-selective NSAIDs. No antiplatelet effect, safe to continue perioperatively. No respiratory depression.
PBS status ✔ PBS General Benefit

Adjunctive Analgesics

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Gabapentin
Neurontin® · Gabahexal® · Gabapentinoid
Perioperative dose (adult) 300–600 mg PO 1–2 hours preoperatively, then 300 mg PO BD–TDS for 48–72 hours
Renal adjustment eGFR 30–59: max 300 mg BD; eGFR 15–29: 300 mg daily; eGFR < 15: 300 mg alternate days
Key warning ⚠️ Respiratory depression risk INCREASES when combined with opioids. Use lower doses (300 mg single preoperative dose) and avoid postoperative continuation in patients with severe OSA. Do not combine with other CNS depressants.
PBS status ⚕️ PBS Authority Required (for neuropathic pain; perioperative use may be non-PBS)
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Pregabalin
Lyrica® · Gabapentinoid
Perioperative dose (adult) 75–150 mg PO 1–2 hours preoperatively. Consider 75 mg PO BD for 48 hours postoperatively.
Renal adjustment eGFR 30–60: 25–75 mg BD; eGFR 15–30: 25–50 mg daily; eGFR < 15: 25 mg daily
Key warning ⚠️ Same opioid co-depression concern as gabapentin. Use minimum effective dose. Avoid in patients already receiving benzodiazepines.
PBS status ⚕️ PBS Authority Required (for neuropathic pain; perioperative use may be non-PBS)
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Ketamine (low-dose)
Ketamine · NMDA receptor antagonist / analgesic adjunct
Adult dose Sub-anaesthetic: 0.1–0.25 mg/kg IV bolus intraoperatively ± 0.1–0.15 mg/kg/hour infusion for 24 hours
Paediatric dose 0.25–0.5 mg/kg IV bolus (sub-anaesthetic); consult paediatric anaesthetist
Renal/hepatic No major adjustment required. Metabolised hepatically; active metabolite (norketamine) accumulates in hepatic impairment.
Advantage in OSA Low-dose ketamine provides analgesia without respiratory depression and maintains airway reflexes. Emerging evidence supports opioid-sparing benefit in major surgery.
PBS status ✖ Not PBS (hospital use only; S4 — prescription only)

Regional and Neuraxial Anaesthesia

Regional anaesthesia techniques are strongly recommended for patients with SDB, as they provide site-specific analgesia with minimal systemic opioid exposure:

Technique Indications Opioid-Sparing Benefit
Thoracic epidural Major thoracic/upper abdominal surgery Reduces opioid consumption by 40–70%. Gold standard for post-thoracotomy pain.
Transversus abdominis plane (TAP) block Abdominal surgery (open and laparoscopic) Reduces 24-hour morphine equivalents by 30–50%
Erector spinae plane (ESP) block Thoracic and rib surgery Comparable analgesia to epidural with lower complication rate
Peripheral nerve blocks (interscalene, adductor canal, sciatic) Upper and lower limb surgery Can eliminate opioid requirement entirely for 12–24 hours
Spinal anaesthesia (intrathecal morphine) Lower limb/abdominal surgery Prolonged analgesia (12–24 hours) from single dose; but note respiratory depression risk with intrathecal morphine — monitoring required
Wound infiltration / wound catheter All surgical incisions Simple adjunct; reduces rescue opioid requirement by 20–30%

When Opioids Are Necessary

When breakthrough pain persists despite multimodal therapy, opioids may be required but should be prescribed at reduced doses with enhanced monitoring:

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Oxycodone
Endone® · OxyNorm® · Opioid agonist
OSA dose adjustment Start 2.5 mg PO (50% of standard dose). Titrate by 2.5 mg increments. Avoid modified-release formulations in the first 48 hours.
Frequency QID PRN (minimum 4-hourly interval). Reduce to BD–TDS if OSA severe or concurrent sedatives.
Renal adjustment eGFR 10–50: increase interval to Q6–8H. eGFR < 10: avoid if possible; use hydromorphone or fentanyl with extreme caution.
PBS status ⚕️ PBS Restricted Benefit
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Tramadol
Tramal® · Tramadol hydrochloride · Weak opioid / SNRI
OSA dose adjustment Start 25–50 mg PO (reduced from standard 50–100 mg). Titrate cautiously. Max 200 mg/day in OSA.
Frequency Q4–6H PRN
Caution ⚠️ Tramadol lowers seizure threshold and interacts with SSRIs/SNRIs (serotonin syndrome risk). Still causes respiratory depression, albeit less than strong opioids. Not a safe alternative in severe OSA.
PBS status ⚕️ PBS Restricted Benefit
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Patient-controlled analgesia (PCA) in OSA: If PCA morphine or PCA oxycodone is required in patients with moderate-to-severe OSA, continuous background infusions MUST be avoided. Use demand-only PCA with standard bolus doses reduced by 50% and mandatory 1-hourly lockout intervals with nursing assessment. Capnography monitoring is mandatory for all PCA use in OSA patients.

Postoperative Monitoring

Postoperative monitoring intensity should be stratified according to OSA severity, type of surgery, and analgesic regimen. The ACSQHC Standard 8 (Recognising and Responding to Acute Deterioration) requires that all patients have documented observation and response plans, with escalated monitoring for those at increased risk of respiratory deterioration.

Monitoring Tiers

Tier 1
Low-Risk OSA + Non-Opioid Regimen
Standard post-anaesthesia observations. Continuous pulse oximetry for first 2 hours post-extubation. Standard 1-hourly observations (respiratory rate, SpO₂, sedation score) for 12 hours.
Setting: General surgical ward
Tier 2
Moderate OSA + Any Opioid OR Low-Risk OSA + Parenteral Opioid
Continuous pulse oximetry overnight for minimum 24 hours. 2-hourly respiratory observations including sedation score (RASS or Pasero). Ensure CPAP used if prescribed. Continuous ECG monitoring if coexistent cardiac disease.
Setting: Monitored bed, step-down unit, or telemetry-capable ward
Tier 3
Severe OSA, OHS, or PCA/IV Opioid Infusion
Continuous pulse oximetry + end-tidal CO₂ (capnography) monitoring. 1-hourly respiratory observations. Apnoea alarms enabled. Mandatory CPAP/BiPAP. Consider supplemental oxygen titrated to SpO₂ 88–92% (avoid over-oxygenation masking hypoventilation).
Setting: HDU or ICU. ICU if OHS or post-major surgery.

Continuous Capnography

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Standard pulse oximetry alone is insufficient to detect early hypoventilation in patients receiving supplemental oxygen. High-flow oxygen can maintain SpO₂ > 95% despite progressive hypercapnia and impending respiratory arrest. Continuous end-tidal CO₂ (capnography) or transcutaneous CO₂ monitoring provides earlier warning of ventilatory failure. This is recommended for all Tier 3 patients and considered for Tier 2 patients receiving parenteral opioids.

Sedation Scoring — Pasero Opioid-Induced Sedation Scale (POSS)

Score Level Description Action
S1Wide awakeAlert, orientedContinue current management
S2Slightly drowsyEasily aroused verballyContinue; monitor closely
S3Moderately drowsyAroused with gentle tactile stimulation⚠️ Defer opioid dose; reassess in 30 minutes; notify medical officer
S4Very drowsyAroused only with vigorous physical stimulation🚨 STOP opioids; withhold next dose; call MET/Rapid Response; administer naloxone if respiratory depression
S5UnarousableCannot be aroused🚨 EMERGENCY — activate Code Blue/MET; naloxone 0.4–2 mg IV/IM; airway management

Naloxone — Emergency Reversal

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Naloxone Hydrochloride
Narcan® · Opioid antagonist
Adult dose Initial: 0.04–0.4 mg IV/IM/SC titrated every 2–3 minutes. Severe: 0.4–2 mg IV push. May repeat up to 10 mg total.
Paediatric dose 0.01–0.1 mg/kg IV/IM (initial); max single dose 0.4 mg in children < 5 years; 2 mg in children 5–12 years
Onset / Duration IV onset: 1–2 minutes. IM onset: 2–5 minutes. Duration: 30–90 minutes (shorter than most opioids — re-dosing may be required).
Key warning ⚠️ OSA patients: Use lower initial doses (0.04 mg IV) and titrate. Abrupt full reversal may cause acute pain, sympathetic surge (hypertension, tachycardia, pulmonary oedema), nausea/vomiting, and aspiration risk. A continuous infusion (2/3 of the effective reversal dose per hour) may be required for long-acting opioids.
PBS status ✔ PBS General Benefit

CPAP / BiPAP Perioperative Management

1
Preoperative
Patients must bring their own CPAP/BiPAP device and mask to hospital. Confirm settings (pressure, mode, ramp, humidification). Document in the anaesthetic record.
2
PACU / Recovery
Commence CPAP as soon as the patient is awake and cooperative (usually within 30–60 minutes of extubation). Nursing staff should be trained in CPAP application and troubleshooting. Continue CPAP during any sleep period.
3
Ward / HDU
CPAP must be used every time the patient sleeps, including daytime naps. Continue until discharge. If not previously diagnosed, arrange outpatient sleep study and CPAP titration.
4
Newly Diagnosed
For newly identified high-risk patients without prior CPAP: consider empiric CPAP (typically 8–12 cm H₂O) or arrange urgent sleep physician review. Consult respiratory/sleep medicine team for guidance.

Discharge Criteria Following Ambulatory Surgery

  • Minimum 3 hours elapsed since last opioid dose without desaturation or excessive sedation (POSS S1–S2).
  • SpO₂ ≥ 92% on room air (or at baseline) for ≥ 30 minutes without supplemental oxygen.
  • Respiratory rate 10–20 breaths/minute, stable and regular.
  • Patient ambulatory, tolerating oral fluids, and oriented.
  • Responsible adult escort available; patient must NOT drive for 24 hours if any opioid received.
  • Written discharge instructions provided including: warning signs of respiratory depression, home CPAP use, opioid dose and duration limits, and when to call 000.
  • Patients with moderate-to-severe OSA requiring parenteral opioids should NOT undergo ambulatory surgery — consider overnight admission with appropriate monitoring.

Sedative Co-Use — Dangerous Combinations

The concurrent use of sedative agents with opioids in patients with SDB creates a synergistic effect on central respiratory depression that far exceeds the risk of either agent alone. This is a leading contributor to perioperative respiratory adverse events and deaths. The following combinations require particular vigilance:

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FDA Black Box Warning (2016, reinforced 2023): Concomitant use of opioids with benzodiazepines or other CNS depressants results in profound sedation, respiratory depression, coma, and death. This warning applies equally to gabapentinoids at higher doses. In OSA patients, even standard doses of these combinations may be lethal.

High-Risk Combinations

Combination Risk Level Mechanism Clinical Guidance
Opioid + Benzodiazepine (diazepam, midazolam, temazepam) EXTREME Synergistic GABAergic and μ-opioid depression of respiratory centres AVOID concurrent use. If benzodiazepine essential (e.g., seizure disorder, acute alcohol withdrawal), use lowest effective dose, cease opioid, and escalate monitoring to Tier 3.
Opioid + Gabapentin/Pregabalin (high dose) HIGH GABAergic potentiation of opioid respiratory depression. Pregabalin ≥ 300 mg/day carries highest risk. Use lowest perioperative gabapentinoid dose (gabapentin 300 mg or pregabalin 75 mg). Avoid postoperative continuation if possible. Escalate monitoring.
Opioid + Promethazine / First-generation antihistamines HIGH Sedation + anticholinergic effects increase airway obstruction and reduce arousal Avoid promethazine as antiemetic. Use ondansetron (4 mg IV/PO) or dexamethasone (4–8 mg IV) as alternatives.
Opioid + Alcohol EXTREME Combined CNS and respiratory depression Alcohol must be ceased perioperatively. Screen for alcohol use disorder and manage withdrawal risk (CIWA-Ar protocol).
Opioid + Zolpidem / Zopiclone (Z-drugs) EXTREME Respiratory depression identical to benzodiazepine-opioid combination Cease Z-drugs perioperatively. If insomnia is severe, non-pharmacological sleep hygiene measures and melatonin (2–3 mg PO nocte) are safer alternatives.
Opioid + Clonidine / Dexmedetomidine MODERATE–HIGH α₂-agonist sedation + hypotension compounds respiratory depression Dexmedetomidine may be used as opioid-sparing sedative in HDU/ICU with continuous monitoring, but does not replace the need for respiratory monitoring.

Perioperative Medication Reconciliation

A thorough preoperative medication reconciliation is essential for all patients with SDB. The following home medications require specific perioperative management:

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  • Home opioids: Continue at reduced dose if chronic pain. Taper if surgical pain will be managed by other modalities. Do not abruptly cease long-term opioids (withdrawal risk).
  • Home benzodiazepines: Cease perioperatively if safely possible. If long-term benzodiazepine use (risk of withdrawal seizures), substitute with low-dose IV midazolam or oral lorazepam at equivalent dose with anaesthetist guidance.
  • Cannabis / THC products: Increasingly common in Australian patients. Cannabis causes upper airway relaxation and potentiates opioid and sedative effects. Cease at least 24 hours preoperatively. Inform anaesthetist.
  • Alcohol dependence: Screen all patients. Implement CIWA-Ar monitoring and symptom-triggered benzodiazepine therapy if indicated, while accounting increased OSA risk with alcohol withdrawal.
  • Insomnia medications (melatonin, antihistamines): Melatonin (2–3 mg PO) may be continued as a sleep aid in hospital. Antihistamines should be avoided.

Antiemetic Choices in OSA

Postoperative nausea and vomiting (PONV) is common and contributes to opioid use. However, antiemetic selection must balance PONV relief against respiratory depression risk:

Antiemetic OSA Safety Notes
Ondansetron 4 mg IVPreferredFirst-line PONV treatment. No respiratory depression. QTc prolongation risk — avoid if QTc > 500 ms.
Dexamethasone 4–8 mg IVPreferredEffective adjunct. Give at induction. Also reduces postoperative pain and opioid requirement. Monitor BGL in diabetic patients.
Droperidol 0.625 mg IVSafeEffective antiemetic. Minimal respiratory depression. May cause QTc prolongation and extrapyramidal symptoms.
Promethazine 12.5–25 mg IV/IMAvoidSedating. Potentiates opioid respiratory depression. Anticholinergic effects worsen airway obstruction.
Metoclopramide 10 mg IVSafeProkinetic. No respiratory depression. Avoid in bowel obstruction.

Special Populations

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Paediatrics

OSA is common in children (prevalence 1–5%) due to adenotonsillar hypertrophy. Most paediatric OSA is cured by adenotonsillectomy.
Children with OSA have exaggerated respiratory sensitivity to opioids. Use codeine with extreme caution — it is now contraindicated in children < 12 years and in those with known CYP2D6 ultra-rapid metaboliser genotype (TGA safety advisory 2019).
Paracetamol (15 mg/kg QID) + ibuprofen (5–10 mg/kg TDS) as first-line. Intranasal fentanyl (1.5 μg/kg) for procedural analgesia. Morphine 0.1 mg/kg IV for severe pain with continuous SpO₂ monitoring.
All children with OSA undergoing adenotonsillectomy should be observed overnight in hospital, not discharged as day surgery. Mandatory continuous pulse oximetry for minimum 6 hours post-extubation.
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Pregnancy

OSA prevalence increases during pregnancy (especially 3rd trimester) and is associated with gestational hypertension, pre-eclampsia, gestational diabetes, and fetal growth restriction.
STOP-BANG screening should be performed at antenatal booking and again in the 3rd trimester. Home CPAP is safe in pregnancy. Opioid use should be minimised; paracetamol and regional anaesthesia are preferred. Avoid NSAIDs after 30 weeks gestation (risk of premature closure of the ductus arteriosus).
Labour analgesia: Neuraxial (epidural/spinal) is preferred and safe. Avoid parenteral opioids (pethidine/morphine) in labouring women with OSA unless continuous fetal and maternal monitoring is available.
Post-caesarean section: TAP block + regular paracetamol + celecoxib (if not contraindicated) + low-dose oral opioid PRN. Breastfeeding-compatible opioids (morphine, oxycodone) at lowest dose for shortest duration. Monitor neonate for respiratory depression if mother receiving opioids.
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Elderly (≥ 65 years)

OSA prevalence is 20–30% in adults over 65 years. Age-related changes in respiratory physiology (reduced chest wall compliance, decreased chemosensitivity, sarcopenia of upper airway muscles) amplify opioid-related respiratory risk.
START WITH 50% of standard opioid dose in elderly OSA patients. Avoid tramadol (seizure risk, serotonergic interactions with common geriatric medications). Avoid codeine (unpredictable metabolism, constipation). Use paracetamol ± NSAIDs (if no renal/GI contraindications) ± regional techniques as first-line.
Polypharmacy is the norm — review all home medications for sedative effects (benzodiazepines, antihistamines, antipsychotics, anticonvulsants). Falls risk is compounded by opioids + sedatives + postoperative immobility.
Elderly patients with OSA should not be placed in a room where nursing observations are delayed. Ensure bed is at lowest height, call bell is accessible, and lights are on for overnight checks. Consider 1:1 or 1:2 nursing ratios for the first night if Tier 3 monitoring.
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Renal Impairment

Chronic kidney disease (CKD) is an independent risk factor for OSA (prevalence up to 50% in dialysis patients). Uraemic upper airway oedema and fluid overload contribute to pharyngeal narrowing.
Opioid metabolism is impaired in CKD. Morphine-6-glucuronide (active metabolite) accumulates in renal failure and causes prolonged respiratory depression. AVOID morphine if eGFR < 30. Preferred opioids in renal impairment: fentanyl (hepatic metabolism, no active renally-excreted metabolites) or hydromorphone (use with caution, reduce dose 50%).
Paracetamol: safe to use at standard dose (1 g QID) if eGFR ≥ 10; reduce to 1 g BD if eGFR < 10 or dialysis-dependent. NSAIDs: avoid if eGFR < 30. Gabapentin: mandatory dose reduction in CKD (see gabapentin renal dosing table above).
Haemodialysis does not effectively clear opioid metabolites. Patients on dialysis receiving opioids require HDU monitoring. Naloxone should be immediately available.
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Hepatic Impairment

Chronic liver disease and OSA overlap significantly in the context of obesity, alcohol use disorder, and non-alcoholic fatty liver disease (NAFLD). Cirrhosis alters opioid pharmacokinetics (reduced first-pass metabolism, increased bioavailability, decreased protein binding).
Reduce opioid doses by 50% in Child-Pugh B and 75% in Child-Pugh C cirrhosis. Avoid codeine and tramadol (unpredictable hepatic metabolism). Paracetamol is safe at ≤ 2 g/day in chronic liver disease — avoid in acute liver failure. Avoid NSAIDs if possible (hepatorenal syndrome risk, GI bleeding).
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Immunocompromised

Immunocompromised patients (transplant recipients, HIV on antiretrovirals, chemotherapy, biologics) may have drug interactions affecting opioid and sedative metabolism. Protease inhibitors (ritonavir) inhibit CYP3A4, dramatically increasing levels of many opioids.
Review antiretroviral and immunosuppressant interactions before prescribing opioids. Transplant patients on tacrolimus/cyclosporine: avoid tramadol (reduces seizure threshold, interacts with calcineurin inhibitor metabolism). Use morphine or hydromorphone with dose adjustment. Monitor closely with Tier 2–3 postoperative monitoring.

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

Sleep-disordered breathing disproportionately affects Aboriginal and Torres Strait Islander Australians. The 2018–19 National Aboriginal and Torres Strait Islander Health Survey (AIHW) reported that Indigenous Australians experience significantly higher rates of obesity (38% vs 31%), type 2 diabetes (approximately 2.5 times non-Indigenous rates), cardiovascular disease (1.4 times), and chronic kidney disease — all established risk factors for OSA. Despite this, access to sleep medicine services, diagnostic polysomnography, and CPAP therapy is severely limited in rural and remote Indigenous communities.

Diagnostic access
Sleep studies (home and in-lab PSG) are available only in major regional centres and capital cities. Remote and very remote communities may require patients to travel hundreds of kilometres for a sleep study, creating significant barriers to diagnosis. Telehealth sleep medicine consultations (MBS item 91790) can partially bridge this gap but cannot replace the need for diagnostic studies.
CPAP access and adherence
CPAP devices require electricity, regular mask replacement, and cleaning — all of which are challenging in some remote communities. The cost of CPAP equipment (machine 0–2,500; masks 0–300 replacement every 6–12 months) may be prohibitive. Some state/territory programs provide CPAP equipment on loan through hospital respiratory departments. The Closing the Gap PBS co-payment measure ensures Indigenous Australians pay a reduced PBS co-payment for PBS-listed medications, though CPAP itself is not PBS-listed.
Cultural safety in pain assessment
Pain expression varies across cultures. Standard 0–10 numerical rating scales may not be culturally appropriate for all Indigenous patients. Visual pain assessment tools (e.g., the Abbey Pain Scale for non-verbal patients, or culturally validated visual analogue scales) should be used. Involve Aboriginal and Torres Strait Islander health workers and liaison officers in pain assessment and management planning. Recognise that stoicism or under-reporting of pain may occur due to cultural factors, previous negative healthcare experiences, or distrust of the healthcare system.
Opioid safety and social determinants
Indigenous Australians in some communities face elevated risk of opioid diversion, misuse, and harm. Multimodal opioid-sparing regimens are even more important in this context. Ensure that discharge opioid prescriptions are appropriate in quantity and duration. Use real-time prescription monitoring systems (e.g., SafeScript in Victoria, ScriptCheck in NT, QScript in Queensland) to identify patients at risk of opioid-related harm. Provide opioid safety counselling including naloxone provision (PBS-listed, available without prescription since 2022) where risk factors are present.
Perioperative care for rural/remote patients
Many Indigenous patients requiring surgery travel to regional or metropolitan hospitals (Patient Assisted Travel Scheme — PATS). Postoperative monitoring capacity in remote health clinics is limited (no HDU, minimal overnight nursing). Ensure that opioid prescriptions at discharge are safe for the level of monitoring available at the patient's home community. Liaise with the local Aboriginal Community Controlled Health Organisation (ACCHO) for postoperative follow-up planning. Consider extended inpatient stay rather than early discharge with opioids if monitoring at home is inadequate.
Obesity and OSA
The prevalence of overweight and obesity in Indigenous adults exceeds 70% in some jurisdictions (AIHW 2022). Central obesity (waist circumference) is a stronger predictor of OSA than BMI alone. Health promotion addressing weight management, smoking cessation (Indigenous smoking rates remain approximately 2.5 times non-Indigenous rates), and chronic disease management through ACCHOs is essential for long-term OSA prevention and management.

📚 References

  1. 1. Chung F, Abdullah HR, Liao P. STOP-Bang questionnaire: a practical approach to screen for obstructive sleep apnea. Chest. 2016;149(3):631–638.
  2. 2. American Society of Anesthesiologists. Practice guidelines for the perioperative management of patients with obstructive sleep apnea: an updated report. Anesthesiology. 2023;138(1):27–46.
  3. 3. Australian and New Zealand College of Anaesthetists (ANZCA). PS09 — Guidelines on the Provision of Anaesthesia Services for Day Surgery. Melbourne: ANZCA; 2023.
  4. 4. Australian Commission on Safety and Quality in Health Care (ACSQHC). National Safety and Quality Health Service Standards. 2nd ed. Sydney: ACSQHC; 2021.
  5. 5. Memtsoudis SG, Cozowicz C, Nagappa M, et al. Society of Anesthesia and Sleep Medicine guideline on intraoperative management of adult patients with obstructive sleep apnea. Anesth Analg. 2023;136(5):874–891.
  6. 6. Australian Institute of Health and Welfare (AIHW). Aboriginal and Torres Strait Islander Health Performance Framework: Summary report 2023. Canberra: AIHW; 2023.
  7. 7. Lam T, Wong K, Grunstein RR, Naughton MT. Sleep-disordered breathing in Australia: the need for greater awareness and action. Med J Aust. 2021;215(11):504–506.
  8. 8. Cozowicz C, Poeran J, Memtsoudis SG. Epidemiology, trends, and disparities in regional anaesthesia for orthopaedic surgery. Br J Anaesth. 2020;125(3):276–287.
  9. 9. Weingarten TN, Chong EY, Schroeder DR, Sprung J. Predictors and outcomes following naloxone administration during Phase I anesthesia recovery. J Anesth. 2016;30(1):116–123.
  10. 10. Duceppe E, Parlow J, Bose R, et al. Canadian Cardiovascular Society guidelines on perioperative cardiac risk assessment and management for patients who undergo noncardiac surgery. Can J Cardiol. 2024;40(1):46–76.
  11. 11. Pasero C, McCaffery M. Monitoring opioid-induced sedation: the Pasero Opioid-Induced Sedation Scale (POSS). American Journal of Nursing. 2009;109(9):66–68.
  12. 12. Royal Australian College of General Practitioners (RACGP). Management of type 2 diabetes: A handbook for general practice. Melbourne: RACGP; 2020. [Relevant to comorbidity management in OSA.]
  13. 13. Food and Drug Administration (FDA). FDA Drug Safety Communication: FDA warns about serious breathing problems with seizure and nerve pain medicines gabapentin (Neurontin, Gralise, Horizant) and pregabalin (Lyrica, Lyrica CR) when used with medicines that make it hard to breathe. Silver Spring, MD: FDA; 2019.
  14. 14. Chai-Coetzer CL, Antic NA, McEvoy RD. Ambulatory models of care for obstructive sleep apnoea: diagnosis, management and implementation. Respirology. 2023;28(4):330–340.
for PBS scripts. Utilise ACCHS pharmacies and Remote Area Aboriginal Health Worker programs for medication supply in remote areas. Avoid initiating benzodiazepines; support holistic pain management including community-based exercise programs.
Preventive health
Promote bone health: encourage vitamin D supplementation (1000 IU daily in deficient individuals), smoking cessation support, reduction of alcohol intake, and weight-bearing exercise. MBS Item 715 health checks provide a structured opportunity to assess bone health, screen for osteoporosis risk factors, and discuss musculoskeletal health in a culturally safe context.

Quick Reference: Differential Diagnosis at a Glance

Costovertebral dysfunction
Paracetamol ± NSAID; manual therapy
2–6 weeks
Provocable on palpation; no red flags
Thoracic compression fracture
Paracetamol; ± calcitonin; DXA + osteoporosis Rx
6–12 weeks healing
Elderly; osteoporosis; acute onset
ACS (posterior MI)
Aspirin 300 mg, GTN, heparin; urgent PCI
Time-critical
ECG, troponin; CV risk factors
Aortic dissection
IV labetalol; urgent CT aortogram; surgery (Type A)
Time-critical
Tearing pain; BP differential >20 mmHg
Vertebral osteomyelitis
IV antibiotics (vancomycin + ceftriaxone initially); ID consult
6 weeks IV antibiotics
Fever, elevated CRP, IV drug use
Biliary colic / cholecystitis
Paracetamol ± morphine; lap cholecystectomy
Surgical within 72 h (cholecystitis)
RUQ/infrascapular; post-prandial; RUQ US

📚 References

  1. 1. Briggs AM, Smith AJ, Straker LM, Bragge P. Thoracic spine pain in the general population: prevalence, incidence and associated factors in children, adolescents and adults. A systematic review. BMC Musculoskelet Disord. 2009;10:77.
  2. 2. National Health and Medical Research Council (NHMRC). Evidence-based management of acute musculoskeletal pain. Canberra: NHMRC; 2003 (updated 2020).
  3. 3. Australian Institute of Health and Welfare (AIHW). Aboriginal and Torres Strait Islander Health Performance Framework: Summary report 2023. Canberra: AIHW; 2023.
  4. 4. Deyo RA, Rainville J, Kent DL. What can the history and physical examination tell us about low back pain? JAMA. 1992;268(6):760–765.
  5. 5. Stochkendahl MJ, Kjaer P, Hartvigsen J, et al. National Clinical Guidelines for non-surgical treatment of patients with recent onset low back pain or lumbar radiculopathy. Europ Spine J. 2018;27(1):60–75.
  6. 6. Erwin WM, Jackson PC, Homonko DA. Innervation of the human costovertebral joint: implications for clinical back pain syndromes. J Manipulative Physiol Ther. 2000;23(6):395–403.
  7. 7. Royal Australian College of General Practitioners (RACGP). Guidelines for preventive activities in general practice. 9th edn. Melbourne: RACGP; 2018 (updated 2023).
  8. 8. Hirsch JA, Singh V, Falco FJE, et al. Thoracic facet joint interventions. Pain Physician. 2016;19(4):E581–E593.
  9. 9. Erwin WM, Jackson PC. The costovertebral joint: anatomy, biomechanics, and clinical significance in thoracic back pain syndromes. J Can Chiropr Assoc. 2003;47(2):112–120.
  10. 10. Strayer RJ, Gunnerson JM, Brown LH, et al. Aortic dissection: clinical features, diagnosis, and management. Aust Crit Care. 2019;32(2):144–153.
  11. 11. Ombregt L. A system of orthopaedic medicine. 3rd edn. Edinburgh: Churchill Livingstone Elsevier; 2013. Chapter 18: Thoracic spine.
  12. 12. Lin CC, Chen KH, Li DM, et al. Characteristics and outcomes of patients presenting with thoracic back pain to the emergency department. Emerg Med Australas. 2020;32(5):805–811.
for PBS-listed medicines at participating pharmacies.
Cultural safety
Engagement with Aboriginal Community Controlled Health Organisations (ACCHOs) is essential. Cultural safety training for non-Indigenous clinicians, use of Aboriginal Health Workers and Liaison Officers, and incorporation of traditional healing practices alongside Western medicine improve treatment adherence and outcomes. Avoidance of eye contact, respect for gender-sensitive examination practices, and understanding of sorry business protocols are critical elements of culturally safe care.
Medication adherence
Complex DMARD regimens with frequent monitoring requirements present adherence challenges. Long-acting depot injections (e.g., methotrexate SC) may improve adherence compared to oral regimens. Community pharmacy partnerships through the Indigenous Pharmacy Programmes improve medication management.
Specific conditions
Rheumatic heart disease (RHD) requires secondary prophylaxis with benzathine penicillin G (BPG) 1.2 MU IM every 3–4 weeks for a minimum of 10 years or until age 21 (whichever is longer). RHD registers (e.g., NT RHD Register) facilitate recall and follow-up. The Australian RHD Endgame Strategy targets elimination by 2031.
Referral pathways
Referral through ACCHOs and Aboriginal Hospital Liaison Officers (AHLOs) improves engagement. The Specialist Outreach Assistance Programme provides funded specialist visits to remote communities. NT, WA, and QLD have specific rheumatology outreach programmes targeting Indigenous communities.

📚 References

  1. 1. Australian Institute of Health and Welfare (AIHW). Autoimmune disease in Australia. Cat. no. PHE 312. Canberra: AIHW; 2023.
  2. 2. Fraenkel L, Bathon JM, England BR, et al. 2021 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Care Res. 2021;73(7):924–939.
  3. 3. Fanouriakis A, Kostopoulou M, Alber K, et al. 2019 update of the EULAR recommendations for the management of systemic lupus erythematosus. Ann Rheum Dis. 2019;78(6):736–745.
  4. 4. Chung SA, Langford CA, Maz M, et al. 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Care Res. 2021;73(11):1583–1599.
  5. 5. Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2022 update. Ann Rheum Dis. 2023;82(1):3–18.
  6. 6. Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook. Australian Government Department of Health; 2024. Available from: immunisationhandbook.health.gov.au.
  7. 7. Rheumatic Heart Disease Australia (RHDAustralia). The 2020 Australian guideline for prevention, diagnosis, and management of acute rheumatic fever and rheumatic heart disease. 3rd ed. Darwin: Menzies School of Health Research; 2020.
  8. 8. Pharmaceutical Benefits Scheme (PBS). PBS Schedule. Australian Government Department of Health. Available from: pbs.gov.au. Accessed 2024.
  9. 9. Agarwal S, Cunnington J, Nossent J. Autoimmune disease in Indigenous Australians: a systematic review. Int J Rheum Dis. 2021;24(12):1487–1498.
  10. 10. Pisetsky DS. Antinuclear antibody testing — misunderstood or misused? Clin Immunol. 2023;255:109717.
  11. 11. Bertsias GK, Tektonidou M, Amoura Z, et al. Joint European League Against Rheumatism and European Renal Association–European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis. Ann Rheum Dis. 2012;71(11):1771–1782.
  12. 12. Ledingham J, Deighton C; British Society for Rheumatology Standards, Audit and Guidelines Working Group. Update on the British Society for Rheumatology guidelines for prescribing TNFα blockers in adults with rheumatoid arthritis. Rheumatology. 2005;44(2):155–158.
  13. 13. National Health and Medical Research Council (NHMRC). National statement on ethical conduct in human research. Canberra: NHMRC; 2023 (updated).
for PBS-listed medicines at participating pharmacies.
Cultural safety
Engagement with Aboriginal Community Controlled Health Organisations (ACCHOs) is essential. Cultural safety training for non-Indigenous clinicians, use of Aboriginal Health Workers and Liaison Officers, and incorporation of traditional healing practices alongside Western medicine improve treatment adherence and outcomes. Avoidance of eye contact, respect for gender-sensitive examination practices, and understanding of sorry business protocols are critical elements of culturally safe care.
Medication adherence
Complex DMARD regimens with frequent monitoring requirements present adherence challenges. Long-acting depot injections (e.g., methotrexate SC) may improve adherence compared to oral regimens. Community pharmacy partnerships through the Indigenous Pharmacy Programmes improve medication management.
Specific conditions
Rheumatic heart disease (RHD) requires secondary prophylaxis with benzathine penicillin G (BPG) 1.2 MU IM every 3–4 weeks for a minimum of 10 years or until age 21 (whichever is longer). RHD registers (e.g., NT RHD Register) facilitate recall and follow-up. The Australian RHD Endgame Strategy targets elimination by 2031.
Referral pathways
Referral through ACCHOs and Aboriginal Hospital Liaison Officers (AHLOs) improves engagement. The Specialist Outreach Assistance Programme provides funded specialist visits to remote communities. NT, WA, and QLD have specific rheumatology outreach programmes targeting Indigenous communities.

📚 References

  1. 1. Australian Institute of Health and Welfare (AIHW). Autoimmune disease in Australia. Cat. no. PHE 312. Canberra: AIHW; 2023.
  2. 2. Fraenkel L, Bathon JM, England BR, et al. 2021 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Care Res. 2021;73(7):924–939.
  3. 3. Fanouriakis A, Kostopoulou M, Alber K, et al. 2019 update of the EULAR recommendations for the management of systemic lupus erythematosus. Ann Rheum Dis. 2019;78(6):736–745.
  4. 4. Chung SA, Langford CA, Maz M, et al. 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Care Res. 2021;73(11):1583–1599.
  5. 5. Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2022 update. Ann Rheum Dis. 2023;82(1):3–18.
  6. 6. Australian Technical Advisory Group on Immunisation (ATAGI). Australian Immunisation Handbook. Australian Government Department of Health; 2024. Available from: immunisationhandbook.health.gov.au.
  7. 7. Rheumatic Heart Disease Australia (RHDAustralia). The 2020 Australian guideline for prevention, diagnosis, and management of acute rheumatic fever and rheumatic heart disease. 3rd ed. Darwin: Menzies School of Health Research; 2020.
  8. 8. Pharmaceutical Benefits Scheme (PBS). PBS Schedule. Australian Government Department of Health. Available from: pbs.gov.au. Accessed 2024.
  9. 9. Agarwal S, Cunnington J, Nossent J. Autoimmune disease in Indigenous Australians: a systematic review. Int J Rheum Dis. 2021;24(12):1487–1498.
  10. 10. Pisetsky DS. Antinuclear antibody testing — misunderstood or misused? Clin Immunol. 2023;255:109717.
  11. 11. Bertsias GK, Tektonidou M, Amoura Z, et al. Joint European League Against Rheumatism and European Renal Association–European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis. Ann Rheum Dis. 2012;71(11):1771–1782.
  12. 12. Ledingham J, Deighton C; British Society for Rheumatology Standards, Audit and Guidelines Working Group. Update on the British Society for Rheumatology guidelines for prescribing TNFα blockers in adults with rheumatoid arthritis. Rheumatology. 2005;44(2):155–158.
  13. 13. National Health and Medical Research Council (NHMRC). National statement on ethical conduct in human research. Canberra: NHMRC; 2023 (updated).