Respiratory

Pre-operative pulmonary risk assessment

Clinical Overview and When to Suspect Elevated Pulmonary Risk

— Any procedure with general anesthesia >2 hours

— Thoracic, upper abdominal, aortic, head/neck, neurosurgical, or emergency surgery (highest-risk sites)

— Known COPD, asthma, OSA, interstitial lung disease, pulmonary hypertension, or heart failure

— Current smoker, age >65, BMI extremes, functional dependence

— Recent URI within 4–6 weeks (especially pediatric, but also adult bronchial hyperreactivity)

— Low preoperative SpO₂ (<96% on RA)

— Respiratory infection in last month

— Age ≥65 (steep rise ≥80)

— Preoperative anemia (Hgb ≤10)

— Surgical site (thoracic/upper abd > lower abd > peripheral)

— Duration >3 h, emergent status

Postoperative pulmonary complications (PPCs) include atelectasis, pneumonia, respiratory failure requiring prolonged ventilation, bronchospasm, and exacerbation of chronic lung disease — collectively as common as cardiac complications and a major driver of 30-day mortality, length of stay, and readmission.

Step 3 framing: the pre-op visit is an ambulatory decision node — your job is to (1) estimate baseline risk, (2) optimize modifiable factors, (3) decide whether further testing changes management, and (4) communicate risk to surgeon, anesthesia, and patient.

When to actively assess pulmonary risk:

Highest-yield risk predictors (ARISCAT, Gupta, ACS NSQIP calculators):

Board pearl: Site of incision and duration of surgery are stronger predictors of PPCs than most patient-level comorbidities — a healthy patient undergoing AAA repair is higher risk than a COPD patient undergoing cataract surgery.

Key distinction: Pre-op cardiac risk uses RCRI/METs/ACS-NSQIP MICA; pre-op pulmonary risk uses ARISCAT or Gupta calculators — do not conflate. A patient can be cardiac-cleared yet pulmonary-high-risk, requiring different optimization (incentive spirometry teaching, smoking cessation, bronchodilator tune-up) rather than stress testing.

Presentation Patterns and Key History

— Smoking: pack-years, current vs former, quit date. Cessation ≥4–8 weeks pre-op reduces PPC rates; <4 weeks may transiently increase secretions but still benefits long-term — counsel to quit regardless of timing

— Occupational dusts, asbestos, biologics

— Alcohol use (≥2 drinks/day independently raises PPC and pneumonia risk)

— Dyspnea on exertion — quantify in METs (climbing 2 flights ≈ 4 METs implies functional capacity adequate to tolerate most surgeries)

— Chronic cough, sputum production, hemoptysis

— Wheeze, recent inhaler escalation, prednisone bursts, ED visits, intubations

— Orthopnea, PND, edema (differentiate cardiac dyspnea)

— Snoring, witnessed apneas, daytime somnolence — apply STOP-BANG for OSA

— URI within 2–4 weeks → bronchial hyperreactivity persists 6 weeks; defer elective cases when febrile, productive cough, or wheeze

— COVID-19: current guidance favors delaying elective surgery 4–7 weeks post-infection, longer if symptomatic, hospitalized, or immunocompromised

— Inhaler adherence and technique

— Recent systemic steroids (stress-dose considerations)

— Biologics, immunosuppressants, anticoagulants

— Home oxygen — flow rate, hours/day, baseline SpO₂

The pre-op pulmonary history is structured, not free-form — Step 3 vignettes embed the answer in a few key data points.

Exposure and habit history:

Symptom screen:

Recent illness:

Medication review:

Functional capacity is the single most useful bedside metric: <4 METs (cannot climb a flight, walk 4 blocks, do housework) flags both cardiac and pulmonary high-risk patients.

Step 3 management: When a patient reports <4 METs and has dyspnea of unclear etiology before elective non-cardiac surgery, the next step is usually further workup (PFTs, echo, or CPET) only if results will change management or delay surgery; otherwise proceed with optimization and risk communication.

Physical Exam Findings and Functional Assessment

— Body habitus: BMI <18.5 (cachexia, sarcopenia) and BMI >40 (restrictive physiology, OSA) both elevate PPC risk

— Accessory muscle use, pursed-lip breathing, tripod posture → advanced obstructive disease

— Cyanosis, clubbing → chronic hypoxemia or suppurative lung disease

— Resting SpO₂ on room air — <96% is an ARISCAT risk factor, <92% mandates workup before elective surgery

— Resting RR >20, HR >100 at rest are independently associated with PPCs

— Hypertension or orthostasis may signal volume issues or autonomic dysfunction

— Mallampati class, thyromental distance, neck circumference (>40 cm raises OSA suspicion)

— Tracheal deviation, JVD, accessory cervical muscle hypertrophy

— Barrel chest, decreased expansion, hyperresonance → COPD

— Wheeze (active bronchospasm — defer elective surgery until controlled)

— Crackles — fine basilar (ILD, CHF) vs coarse (infection, bronchiectasis)

— Dullness, decreased breath sounds → effusion or consolidation

— Loud P2, RV heave, TR murmur → pulmonary hypertension (major risk multiplier)

— S3, displaced PMI → LV dysfunction contributing to dyspnea

— Sit-to-stand, 6-minute walk, or simply walking the patient up a flight of stairs in the office

— Inability to climb 1 flight without stopping correlates with poor outcomes after thoracic/abdominal surgery

The pre-op pulmonary exam is brief but high-yield — abnormal findings at the clinic visit are far more predictive than any single lab.

General appearance:

Vitals:

Airway and neck:

Chest exam:

Cardiac:

Extremities: pitting edema, calf tenderness (DVT risk pre-op), clubbing.

Functional testing in clinic:

Board pearl: An unexplained resting SpO₂ <92% in a pre-op patient should halt elective surgery scheduling until the cause is identified — it is the pulmonary equivalent of an unexplained troponin elevation pre-op.

Diagnostic Workup — Initial Labs, Imaging, ECG

— New or unexplained pulmonary symptoms

— Acute cardiopulmonary findings on exam

— Known cardiopulmonary disease with change in status

— Cancer staging or thoracic procedure planning

— SpO₂ <92% on room air unexplained

— Suspected hypercapnia (elevated bicarb, somnolence, severe COPD)

— Pre-op for lung resection

— PaCO₂ >45 identifies CO₂ retainers needing tailored ventilatory and analgesic strategy

Pre-op testing should be driven by findings, not by ritual. Step 3 frequently tests the "do not order" answer.

Routine pre-op CXR is NOT indicated in asymptomatic patients regardless of age. Order CXR only when:

CBC: Anemia (Hgb ≤10) is an independent ARISCAT risk factor — correct iron deficiency pre-op when feasible. Polycythemia suggests chronic hypoxemia.

BMP: Hypercapnic patients may show elevated serum bicarbonate (chronic respiratory acidosis compensation) — a clue to undiagnosed obesity hypoventilation or severe COPD. BUN >21 is in some risk models.

Albumin <3.5 is one of the strongest single predictors of postoperative morbidity, including PPCs.

ABG: Not routine. Obtain when:

ECG: Useful for pulmonary HTN signs (RAD, RBBB, P pulmonale, RVH) and overlapping cardiac risk; not a pulmonary screening test per se.

BNP/NT-proBNP: Helpful when dyspnea etiology is unclear (cardiac vs pulmonary). Elevated BNP pre-op independently predicts cardiac and pulmonary complications.

Glucose/HbA1c: Uncontrolled DM raises pneumonia risk; aim for reasonable control pre-op.

Key distinction: PFTs and CXR are NOT screening tests before non-thoracic surgery — they are confirmatory tests ordered when history/exam suggests undiagnosed or poorly controlled lung disease, or when surgery itself is thoracic.

Step 3 management: For a 68-year-old smoker with stable COPD on tiotropium going to elective hernia repair, the correct pre-op workup is history, exam, SpO₂, and optimization of inhalers — not PFTs, ABG, or CXR.

Diagnostic Workup — Advanced and Confirmatory Studies

— Planned lung resection or lung volume reduction surgery

— Unexplained dyspnea or exercise intolerance after initial workup

— Severity assessment when symptoms seem out of proportion to known disease

— Not required to "clear" COPD or asthma patients for non-thoracic surgery if symptoms are stable and controlled

— Step 1: Spirometry → FEV₁ and DLCO

— Calculate predicted postoperative (ppo) FEV₁ and ppoDLCO based on segments resected

— ppoFEV₁ and ppoDLCO both >60% predicted → proceed

— Either 30–60% → low-tech exercise test (stair climb, shuttle walk)

— Either <30% or poor exercise performance → CPET with VO₂max

· VO₂max >20 mL/kg/min (or >75% predicted) → acceptable

· VO₂max 10–20 → moderate risk, individualize

· VO₂max <10 (or <35% predicted) → very high risk; consider sublobar resection, SBRT, or decline

Pulmonary function tests (PFTs) indications:

Pre-thoracotomy/lung resection algorithm:

Cardiopulmonary exercise testing (CPET) is the gold standard for integrated assessment when functional capacity is unclear — provides VO₂max, anaerobic threshold, and ventilatory reserve.

Echocardiography: Obtain when pulmonary HTN, unexplained dyspnea, or new murmur is suspected. Significant PH (RVSP >50 or PASP elevated with RV dysfunction) markedly raises perioperative risk.

Polysomnography or home sleep apnea test: STOP-BANG ≥3 with elective surgery → consider OSA testing if it will change anesthesia plan or postoperative monitoring; do not delay urgent surgery for sleep study.

High-resolution CT: Reserved for suspected ILD, bronchiectasis, or unexplained imaging findings.

Board pearl: A common Step 3 distractor is ordering PFTs to "clear" a stable COPD patient for cholecystectomy — PFT results in this scenario rarely change management and the correct answer is clinical optimization without PFTs.

CCS pearl: In CCS, ordering "spirometry" or "PFTs" on an asymptomatic non-thoracic surgical candidate wastes simulated time and may lower your score — order it only when the case explicitly raises a question PFTs will answer.

Risk Stratification and Optimization Logic

— ARISCAT score — 7 variables (age, SpO₂, recent respiratory infection, anemia, incision site, duration, emergency) → low/intermediate/high risk

— Gupta calculators for postoperative pneumonia and respiratory failure

— ACS NSQIP risk calculator integrates multiple endpoints

— Smoking cessation — aim ≥4 weeks; offer nicotine replacement, varenicline, bupropion; even short-term cessation reduces wound and pulmonary complications

— COPD/asthma optimization — ensure on guideline-directed inhalers (LAMA ± LABA ± ICS); treat exacerbation before elective surgery

— OSA — initiate or bring CPAP to surgery; document use

— Nutrition — address hypoalbuminemia, weight extremes

— Anemia correction — iron, treat underlying cause

— Vaccination — influenza and pneumococcal where indicated

— Education on incentive spirometry and deep breathing BEFORE surgery — teaching post-op is too late

— Regional or neuraxial anesthesia when feasible

— Laparoscopic vs open

— Lung-protective ventilation (low tidal volume, PEEP, recruitment)

— Short-acting neuromuscular blockers with full reversal (avoid residual paralysis)

— Minimize long-acting opioids; multimodal analgesia

Use a validated calculator rather than gestalt:

Risk categories drive intensity of optimization, not surgical denial — most patients can proceed with mitigation.

Modifiable factors to address pre-op:

Non-modifiable factors (age, surgical site/urgency) → adjust expectations and post-op monitoring rather than alter pre-op.

Surgical/anesthetic strategies to reduce PPCs (discuss with surgeon/anesthesia):

Step 3 management: For a high-ARISCAT patient undergoing elective upper abdominal surgery, the correct pre-op intervention bundle is smoking cessation counseling + inhaler optimization + incentive spirometry teaching + nutrition/anemia correction + plan for regional anesthesia and post-op pulmonary toilet — not a battery of additional tests.

Pharmacotherapy — Pre-Op Pulmonary Medication Management

— Inhaled bronchodilators (SABA, LABA, LAMA) — take as scheduled, including morning of surgery; bring inhaler to OR

— Inhaled corticosteroids — continue uninterrupted

— Leukotriene modifiers (montelukast) — continue

— Oral theophylline — continue, but check level if toxicity suspected

— PDE-4 inhibitors (roflumilast) — continue

— Patients on chronic prednisone ≥5 mg/day for >3 weeks within the past year → at risk for HPA suppression

— For major surgery, give stress-dose hydrocortisone (e.g., 50–100 mg IV at induction, then taper) only when HPA suppression is documented or strongly suspected and the surgery is significant; for minor procedures, continue usual dose

— Do not abruptly stop chronic steroids pre-op

— Active COPD/asthma exacerbation → defer elective surgery; treat with short course oral prednisone, nebulized bronchodilators, and antibiotics if indicated; reassess in 1–2 weeks

— Escalate from SABA-only to scheduled LAMA ± LABA ± ICS per GINA/GOLD

— A 5–7 day course of oral steroids prior to surgery is reasonable in asthmatics with active symptoms despite optimized inhalers

Continue chronic pulmonary medications through the morning of surgery in nearly all cases:

Systemic corticosteroids:

Acute exacerbation pre-op:

Pre-op bronchodilator "tune-up" for poorly controlled patients:

Biologics (omalizumab, mepolizumab, dupilumab, etc.): Continue per usual schedule; no perioperative interruption required.

Nicotine replacement / varenicline / bupropion: Continue through perioperative period; benefits of cessation outweigh theoretical concerns.

Antibiotics: Treat documented infection — do not give prophylactic antibiotics for "chronic bronchitis" pre-op unless meeting criteria for exacerbation (increased dyspnea, sputum volume, sputum purulence).

Board pearl: The most common Step 3 error is holding inhalers the morning of surgery — the correct answer is to administer them, including a SABA pre-induction in patients with reactive airways.

Procedural and Anesthetic Risk Modification

— Neuraxial (spinal/epidural) or peripheral nerve blocks reduce PPCs vs general anesthesia in appropriate cases (lower extremity, lower abdominal, urologic)

— Avoiding intubation avoids ventilator-associated complications

— In high-risk patients, combined regional + light general is preferable to deep general alone

— Tidal volume 6–8 mL/kg predicted body weight

— PEEP 5 cm H₂O minimum, titrated

— Periodic recruitment maneuvers

— FiO₂ targeted to SpO₂ 92–96% (avoid hyperoxia)

— Use shorter-acting agents when feasible

— Quantitative train-of-four monitoring to ensure full reversal

— Sugammadex preferred over neostigmine for rocuronium/vecuronium reversal in high-pulmonary-risk patients — residual paralysis is a major driver of post-op respiratory failure

— Multimodal, opioid-sparing: acetaminophen, NSAIDs (when not contraindicated), gabapentinoids judiciously, regional catheters, intercostal/paravertebral/erector spinae blocks for thoracic-abdominal cases

— Minimize long-acting parenteral opioids; PCA with low basal rates

— Laparoscopic/thoracoscopic < open for PPCs in most settings

— Shorter operative time correlates with fewer PPCs — discuss staging if feasible

— Early mobilization (out of bed POD 0/1)

— Incentive spirometry q1–2h while awake

— Head of bed ≥30°, oral care to reduce VAP/HAP

— CPAP for known OSA from PACU through discharge

— Adequate analgesia to allow deep breathing and cough

Anesthesia and surgical technique choices substantially modify pulmonary risk and are fair game on Step 3 in coordinated-care vignettes.

Anesthesia type:

Intraoperative ventilation strategy (lung-protective):

Neuromuscular blockade:

Analgesia:

Surgical approach:

Post-op bundle (ERAS-aligned):

CCS pearl: In a CCS case of upper abdominal surgery in a smoker with COPD, ordering incentive spirometry, early ambulation, CPAP if OSA, and DVT prophylaxis on POD 0 captures the post-op pulmonary care bundle the grader expects.

Special Populations — Elderly, Renal, and Hepatic Impairment

— Age itself is a non-modifiable ARISCAT risk factor; chest wall stiffening, decreased mucociliary clearance, reduced cough strength, and blunted hypoxic/hypercapnic drive all contribute

— Sarcopenia and frailty (assess via gait speed, grip strength, FRAIL or Clinical Frailty Scale) independently predict PPCs and prolonged ventilation

— Polypharmacy review — sedatives, anticholinergics, and long-acting benzodiazepines should be deprescribed or minimized pre-op (Beers criteria)

— Delirium prevention is intertwined with pulmonary outcomes — delirious patients aspirate, fail to mobilize, and develop pneumonia

— Volume overload increases atelectasis and pulmonary edema risk

— Avoid nephrotoxic NSAIDs in multimodal analgesia

— Adjust gabapentinoid doses (renally cleared) to prevent oversedation and respiratory depression

— Uremic patients have impaired immune function → higher pneumonia risk

— Hepatopulmonary syndrome (intrapulmonary vasodilation, orthodeoxia, low SpO₂ upright) and portopulmonary hypertension dramatically raise risk — screen with SpO₂ supine vs upright and echo with bubble study when suspected

— Ascites causes restrictive physiology and atelectasis — large-volume paracentesis pre-op may improve mechanics

— Hepatic encephalopathy increases aspiration risk

— Coagulopathy affects regional anesthesia choice

Elderly (≥65, especially ≥80):

Chronic kidney disease:

Cirrhosis/hepatic impairment:

Both renal and hepatic disease alter drug clearance — favor short-acting agents with minimal active metabolites (remifentanil, cisatracurium, desflurane).

Step 3 management: A frail 84-year-old with CKD stage 4 and stable COPD scheduled for elective hip replacement should receive frailty assessment, multimodal opioid-sparing analgesia, neuraxial anesthesia when feasible, renal-dosed medications, delirium prevention bundle, and early mobilization — these address pulmonary, cognitive, and renal risk simultaneously.

Key distinction: Hepatopulmonary syndrome causes hypoxemia that worsens upright (orthodeoxia/platypnea) — opposite of orthopnea from heart failure. Spotting this on a pre-op vignette earns the point.

Special Populations — Pregnancy, Pediatrics, OSA, Pulmonary HTN

— Elective non-obstetric surgery deferred until postpartum when possible; urgent surgery best in second trimester

— Physiologic changes: increased minute ventilation, decreased FRC, increased oxygen consumption → rapid desaturation on induction

— Left lateral tilt to avoid aortocaval compression; rapid sequence induction due to aspiration risk

— Continue asthma controllers — uncontrolled asthma is more dangerous to fetus than medication exposure

— Recent URI within 2–4 weeks is the dominant pediatric pulmonary risk factor — bronchial hyperreactivity persists up to 6 weeks; defer elective surgery

— Passive smoke exposure raises laryngospasm and bronchospasm risk

— Children with reactive airway disease benefit from pre-op albuterol

— STOP-BANG ≥3 → screen; ≥5 → high risk

— Bring CPAP/BiPAP to the hospital and use in PACU and overnight

— Avoid long-acting opioids and sedatives; use multimodal analgesia

— Extended post-op monitoring (continuous pulse oximetry) for moderate-severe OSA after major surgery

— Undiagnosed OSA after bariatric or upper airway surgery is a high-yield Step 3 scenario for postoperative respiratory failure

— BMI ≥30 + daytime PaCO₂ ≥45 without other cause

— Higher mortality than OSA alone; arrange BiPAP and consider ICU-level post-op monitoring

— Major independent risk factor — mortality up to 7–10% for non-cardiac surgery in moderate-severe PH

— Continue pulmonary vasodilators (sildenafil, bosentan, prostacyclins) perioperatively

— Avoid hypoxia, hypercarbia, acidosis, and hypotension intraoperatively — all increase PVR

— Plan ICU recovery

Pregnancy:

Pediatrics:

Obstructive sleep apnea:

Obesity hypoventilation syndrome (OHS):

Pulmonary hypertension:

Board pearl: A child with runny nose, low-grade fever, and wheeze 10 days before scheduled tonsillectomy → defer elective surgery 2–4 weeks to reduce laryngospasm and bronchospasm risk.

CCS pearl: For an OSA patient admitted for elective surgery, ordering "CPAP at home settings, continuous pulse oximetry, non-opioid analgesia" post-op captures the safety bundle.

Complications and Adverse Outcomes

— Most common PPC; presents POD 1–2 with low-grade fever, mild hypoxemia, decreased breath sounds at bases

— Treat with incentive spirometry, ambulation, adequate analgesia, chest physiotherapy

— Persistent lobar collapse → bronchoscopy

— Risk factors: age, COPD, aspiration, NG tube, prolonged intubation, supine positioning

— Treat empirically with antipseudomonal/MRSA coverage if hospital-acquired or ventilated, narrow based on cultures

— Aspiration pneumonitis vs pneumonia distinction — chemical pneumonitis usually does not require antibiotics initially

— Causes: residual neuromuscular blockade, opioid oversedation, atelectasis, pneumonia, pulmonary edema, PE

— Address reversible causes; lung-protective ventilation; early SBT/SAT bundle

— Intraoperative or PACU wheezing — treat with deepening anesthesia, albuterol, corticosteroids

— Cardiogenic (fluid overload, LV dysfunction) vs negative-pressure (post-extubation laryngospasm) vs TRALI

— Highest risk POD 7–14 but can occur earlier; chemoprophylaxis (LMWH or UFH) plus mechanical prophylaxis is standard unless contraindicated

— Can follow major surgery, especially with sepsis, aspiration, or massive transfusion; low tidal volume ventilation, prone positioning for severe cases.

Postoperative pulmonary complications occur in 5–10% of major non-cardiac surgeries and up to 30% in high-risk thoracic/upper-abdominal cases.

Atelectasis:

Postoperative pneumonia / HAP / VAP:

Respiratory failure / prolonged mechanical ventilation:

Bronchospasm:

Pulmonary edema:

Pulmonary embolism:

Exacerbation of underlying disease: COPD or asthma flare requires steroids, bronchodilators, and possibly antibiotics; reassess inhaler regimen at discharge.

ARDS:

Mortality: Postoperative respiratory failure carries 25–40% in-hospital mortality; pneumonia adds 3–5 days to LOS.

Key distinction: Day 1 fever + atelectasis on exam = atelectasis or early surgical site issue, not necessarily pneumonia. Empiric antibiotics for POD 1 low-grade fever without infiltrate, leukocytosis, or purulent sputum is the wrong answer — incentive spirometry, ambulation, and observation are correct.

When to Escalate — ICU, Consultation, Inpatient Triage

— Unexplained dyspnea or hypoxemia

— Severe or poorly controlled COPD/asthma requiring optimization

— Suspected interstitial lung disease, pulmonary hypertension, or hepatopulmonary syndrome

— Lung resection candidates needing CPET interpretation

— Recent COVID-19 with persistent symptoms before major surgery

— Active respiratory infection or COPD/asthma exacerbation

— Decompensated heart failure contributing to dyspnea

— Unexplained hypoxemia

— Recent COVID-19 within recommended deferral window without compelling indication to proceed

— Severe COPD with PaCO₂ retention undergoing major surgery

— Pulmonary hypertension undergoing non-cardiac surgery

— OHS or severe OSA after major or upper-airway surgery

— Lung resection with marginal ppoFEV₁/ppoDLCO

— Anticipated prolonged ventilation

— Moderate OSA on CPAP after major surgery

— Elderly patients with multiple risk factors

— Patients on opioid PCA with known sleep-disordered breathing

— Increasing oxygen requirement (FiO₂ >50% to maintain SpO₂ >90%)

— Rising RR, accessory muscle use, falling tidal volumes

— pH <7.30 with rising PaCO₂

— Hemodynamic instability

Pulmonology consultation pre-op — request when:

Anesthesia pre-op clinic referral — high-ARISCAT patients, OSA, OHS, difficult airway, pulmonary hypertension; allows for ventilation, monitoring, and post-op planning ahead of surgery day.

Cancel or defer elective surgery when:

Plan ICU admission post-op for:

Step-down or telemetry with continuous pulse oximetry for:

Triggers for ICU transfer post-op:

CCS pearl: In a CCS case where a post-op COPD patient on the ward develops increasing dyspnea, rising RR, and SpO₂ falling despite supplemental O₂, the right sequence is ABG, CXR, nebulized bronchodilators, steroids, consider BiPAP, transfer to ICU — do not delay escalation waiting for additional imaging.

Board pearl: A patient with severe pulmonary HTN scheduled for elective non-cardiac surgery requires multidisciplinary planning (PH specialist, cardiac anesthesia, ICU) and is rarely "cleared" in a single primary care visit.

Key Differentials — Other Causes of Pre-Op Dyspnea (Pulmonary Category)

— Smoker, chronic productive cough, prolonged expiration, hyperinflation on CXR, obstruction on spirometry (FEV₁/FVC <0.70)

— Optimize with LAMA ± LABA ± ICS; treat exacerbation before elective surgery

— Episodic wheeze, atopy, reversible obstruction; trigger-driven

— Step up controller therapy; pre-op albuterol; consider short steroid course if poorly controlled

— Dry cough, exertional dyspnea, fine basilar crackles ("Velcro"), clubbing, restrictive PFTs with reduced DLCO, reticulation on HRCT

— High peri-op risk for acute exacerbation; consider lung-protective ventilation and minimize FiO₂

— Chronic copious purulent sputum, recurrent infections; optimize airway clearance and treat active infection pre-op

— Exertional dyspnea, syncope, loud P2, RV heave; echo screening

— Continue PH-targeted therapy; ICU post-op for major surgery

— Snoring, witnessed apneas, AM headache, daytime sleepiness, elevated bicarb in OHS

— STOP-BANG, polysomnography if elective and would change plan

— Defer elective surgery 2–6 weeks

— Unexplained dyspnea, prior VTE; V/Q scan; profound implications for anticoagulation and surgical timing

— Inspiratory wheeze (stridor), throat tightness; mimics asthma but does not respond to bronchodilators

Pre-op dyspnea is the chief diagnostic challenge — many causes are pulmonary and require different optimization paths.

COPD:

Asthma:

Interstitial lung disease:

Bronchiectasis:

Pulmonary hypertension:

Obstructive sleep apnea / OHS:

Recent or active respiratory infection:

Pulmonary embolism (chronic thromboembolic disease):

Vocal cord dysfunction / upper airway pathology:

Key distinction: ILD and COPD both cause exertional dyspnea but ILD has restrictive PFTs with reduced DLCO and basilar Velcro crackles, while COPD shows obstructive PFTs, hyperinflation, and prolonged expiration with wheeze. Treatment paths and perioperative implications differ substantially.

Key Differentials — Non-Pulmonary Causes of Pre-Op Dyspnea

— Orthopnea, PND, S3, JVD, peripheral edema, pulmonary congestion on CXR; elevated BNP

— Decompensated HF is a major contraindication to elective surgery; optimize with diuretics, GDMT (ACEi/ARB/ARNI, beta-blocker, MRA, SGLT2i); reassess

— Dyspnea may be anginal equivalent, especially in diabetics, women, elderly

— Apply RCRI; pursue stress testing only if it would change management

— Severe aortic stenosis (slow rising pulse, late-peaking systolic murmur), mitral regurgitation, prosthetic valve dysfunction

— Echo before major surgery if murmur is new or symptomatic

— Common, often missed; correct iron deficiency pre-op, manage chronic disease anemia, transfuse only when clinically indicated

— Common cause of low METs in absence of true cardiopulmonary disease

— Pre-habilitation programs improve perioperative outcomes

— Hyperthyroidism causes dyspnea, tachycardia, anxiety; hypothyroidism causes effusions and hypoventilation

— Diagnosis of exclusion; reassure, address pre-op

— Myasthenia, ALS, muscular dystrophy — assess vital capacity and MIP/MEP; markedly elevated risk for post-op respiratory failure

— Aspiration risk; affects induction strategy

Equally important — many "pulmonary" symptoms before surgery are not pulmonary at all, and the right answer is to redirect workup.

Heart failure:

Coronary artery disease / ischemia:

Valvular disease:

Anemia:

Deconditioning / obesity:

Thyroid disease:

Anxiety/panic:

Neuromuscular disease:

GERD / hiatal hernia:

Renal failure with volume overload, metabolic acidosis — appears as dyspnea but is metabolic

Step 3 management: A 72-year-old with dyspnea on exertion, 3 METs, leg edema, and an S3 before elective knee replacement should get an echocardiogram and HF optimization, not PFTs — picking the cardiac workup is the test point.

Post-Op and Discharge Plan — Pulmonary Bundle

— Head of bed ≥30°

— Incentive spirometry every 1–2 hours awake (10 breaths each)

— Early ambulation, ideally POD 0 or POD 1

— Multimodal analgesia; minimize sedation; avoid stacking opioids with benzodiazepines

— Resume home inhalers and CPAP/BiPAP immediately

— Oral care including chlorhexidine where appropriate to reduce HAP/VAP

— DVT prophylaxis (LMWH or UFH plus mechanical) unless contraindicated

— Continue spirometry, ambulation, pulmonary toilet

— Monitor for atelectasis, pneumonia, PE

— Wean supplemental O₂ to baseline; do not discharge on more oxygen than home unless arranged

— Reconcile home inhalers; ensure technique; consider step-up if hospitalized for exacerbation

— Smoking cessation pharmacotherapy (varenicline, NRT, bupropion) with quit-date counseling — the post-op window is a teachable moment

— Influenza and pneumococcal vaccination if not up to date and clinically appropriate

— VTE prophylaxis duration per procedure (extended prophylaxis for major orthopedic and abdominal cancer surgery)

— Red flags: worsening dyspnea, fever, purulent sputum, pleuritic chest pain, hemoptysis, calf swelling → seek care

— Activity progression and pulmonary rehab when applicable

— Post-COPD exacerbation, post-lung resection, post-prolonged ventilation — improves function, dyspnea, and readmissions

Post-op pulmonary management spans the OR through 30-day follow-up — Step 3 likes the longitudinal view.

Immediate post-op (PACU/POD 0–1):

POD 2 through discharge:

Discharge medications:

Counseling:

Pulmonary rehab referral:

Board pearl: Smoking cessation initiated at discharge after surgery has higher long-term quit rates than counseling outside the perioperative window — always offer pharmacotherapy and follow-up support; this is a high-yield secondary prevention point.

Follow-Up, Monitoring, and Rehabilitation Cadence

— Phone or telehealth check at 48–72 hours post-discharge for symptoms, medication reconciliation, oxygen needs

— In-person at 1–2 weeks: wound, function, inhaler technique, smoking status, vaccination

— 4–6 weeks: assess return to baseline lung function, sustained smoking cessation, pulmonary rehab progress

— Resting SpO₂ trend toward baseline

— Symptom-limited exertion (6-minute walk improvement)

— Inhaler technique reassessment — most patients use inhalers incorrectly without coaching

— Spirometry not routinely repeated unless indicated (post-resection, post-exacerbation, unresolved symptoms)

— Quit-line referral, varenicline up to 12 weeks with extension consideration, nicotine replacement combinations (patch + short-acting), bupropion if appropriate

— Repeat counseling at every visit — relapse is common; Step 3 emphasizes ongoing support, not one-shot advice

— Indicated post-COPD exacerbation, post-lung resection, post-prolonged ventilation

— Reduces readmissions and improves quality of life; reimbursed by Medicare for qualifying diagnoses

— Annual influenza

— Pneumococcal per ACIP (PCV20 or PCV15→PPSV23) for adults ≥65 or with chronic lung disease

— COVID-19 boosters per current guidance

— Tdap, zoster, RSV per age-appropriate guidance

Outpatient follow-up after major surgery in pulmonary high-risk patients:

Monitoring parameters:

Smoking cessation follow-up:

Pulmonary rehabilitation:

Vaccination:

CPAP adherence in OSA patients — confirm at follow-up; nonadherence may prompt mask refitting, humidification, or BiPAP transition.

Address frailty and deconditioning with prehabilitation if additional surgeries are anticipated.

Step 3 management: A COPD patient hospitalized for postoperative pneumonia should be discharged with antibiotic completion, optimized inhalers, smoking cessation pharmacotherapy, pulmonary rehab referral, pneumococcal vaccination if due, and a 1–2 week follow-up visit — this bundle is the high-yield checklist.

Ethical, Legal, and Patient Safety Considerations

— Patients with severe COPD, pulmonary HTN, or OHS facing major surgery require explicit risk discussion including post-op respiratory failure, prolonged ventilation, ICU stay, tracheostomy, and mortality estimates

— Decision should be documented and shared with surgeon and anesthesia; patient should understand non-surgical alternatives

— Hypoxic, hypercapnic, or delirious patients may lack capacity — defer non-emergent consent until corrected, or invoke surrogate decision maker per state hierarchy

— Do not assume DNR is suspended in the OR. Best practice is "required reconsideration" — discuss specific intraoperative resuscitation (intubation, defibrillation, vasopressors) and document preferences. Patients may suspend, modify, or maintain DNR for the procedure.

— Failure to clarify is a common board scenario for ethical missteps

— Lung resection with borderline ppoFEV₁/ppoDLCO — present alternatives (SBRT, sublobar resection, surveillance) and elicit patient values

— Active tuberculosis or other communicable respiratory infection pre-op → isolate, report to public health, defer elective surgery

— Medication reconciliation at pre-op, admission, transfer between units, and discharge — inhalers and CPAP settings are frequently dropped

— Handoff communication (e.g., I-PASS, SBAR) between PACU, ward, and outpatient teams; pulmonary risk patients require explicit handoff of oxygen needs, ventilation history, and follow-up plan

— Confirm home CPAP/BiPAP settings with the patient or sleep physician — wrong settings post-op are a documented harm

— Pneumonia, prolonged intubation, unintended ICU stay should be disclosed honestly and documented per institutional and ethical norms

Pre-op evaluation is a dense node of safety and ethics issues — Step 3 vignettes frequently test these.

Informed consent for high-risk patients:

Capacity assessment:

Advance directives and DNR/DNI:

Shared decision-making for marginal candidates:

Mandatory reporting and public health:

Transition-of-care safety (high-yield Step 3):

Disclosure of complications:

Board pearl: A patient with a DNR order arriving for elective surgery requires a specific pre-op conversation about whether the DNR is suspended, modified, or maintained intraoperatively — never assume; document the decision and communicate to OR team.

High-Yield Associations and Rapid-Fire Facts

ARISCAT seven variables: age, preop SpO₂, respiratory infection last month, anemia (Hgb ≤10), surgical incision (peripheral/upper abd/intrathoracic), duration (<2/2–3/>3 h), emergency.

Surgical site is the strongest predictor: thoracic ≈ upper abdominal > AAA > head/neck > lower abdominal > peripheral.

Smoking cessation ≥4 weeks pre-op reduces PPCs and wound complications; even shorter cessation benefits long-term despite transient secretion increase.

CXR is NOT routine in asymptomatic pre-op patients.

PFTs are NOT routine before non-thoracic surgery; reserved for lung resection or unexplained dyspnea.

Pre-op spirometry doesn't "clear" anyone — clinical optimization does.

ppoFEV₁ and ppoDLCO >60% generally safe for lung resection.

CPET VO₂max <10 mL/kg/min generally precludes major resection.

Recent URI in children → defer elective surgery 2–4 weeks.

COVID-19 elective surgery deferral: ~4–7 weeks asymptomatic, longer if hospitalized or symptomatic.

OSA STOP-BANG ≥3 → screen further; ≥5 → high risk.

Pulmonary HTN is a major risk multiplier — plan ICU, continue PH meds, avoid hypoxia/hypercarbia/acidosis.

Hepatopulmonary syndrome: orthodeoxia/platypnea, low SpO₂ upright, positive bubble echo.

Albumin <3.5 strongest single predictor of postoperative morbidity.

Continue inhalers the morning of surgery; bring to OR.

Stress-dose steroids only for documented HPA suppression undergoing major surgery.

Lung-protective ventilation: TV 6–8 mL/kg PBW, PEEP ≥5, recruitment.

Avoid residual neuromuscular blockade — quantitative TOF, full reversal (sugammadex preferred in high-risk).

Multimodal opioid-sparing analgesia + regional anesthesia → fewer PPCs.

Incentive spirometry, early ambulation, head of bed elevation are the post-op trio.

Pulmonary rehab post-COPD exacerbation or post-resection reduces readmission.

DNR in OR requires required reconsideration — never auto-suspended.

CCS pearl: Order the pre-op bundle as a single block: SpO₂, CBC/BMP, albumin if malnourished, inhalers continued, smoking cessation counseling, incentive spirometry teaching, anesthesia consult for high-risk.

Board Question Stem Patterns

— 62-year-old smoker, stable COPD on tiotropium, going to elective inguinal hernia repair. SpO₂ 95%. Next step?

— Answer: Proceed with surgery; counsel smoking cessation; continue inhalers — not PFTs, CXR, or ABG.

— 70-year-old pre-op for elective cholecystectomy, SpO₂ 88% on RA, no symptoms. Next step?

— Answer: Defer elective surgery, work up hypoxemia (CXR, ABG, echo, consider PE/ILD/PH).

— 5-year-old scheduled for elective tonsillectomy with productive cough and wheeze 1 week.

— Answer: Postpone elective surgery 2–4 weeks.

— Patient with stage I NSCLC, FEV₁ 65%, DLCO 50%. Next step?

— Answer: Calculate ppoFEV₁/ppoDLCO; if either 30–60%, low-tech exercise test; if <30% or poor performance, CPET.

— Severe OSA patient post-bariatric surgery on opioid PCA develops apnea episodes.

— Answer: Reduce opioid, multimodal analgesia, ensure CPAP use, continuous pulse oximetry, consider step-down/ICU.

— Best management of pre-existing DNR going to OR?

— Answer: Required reconsideration discussion; document the patient's specific preferences for intraoperative resuscitation.

— Patient with moderate PH on sildenafil scheduled for elective surgery.

— Answer: Continue PH-targeted therapy, multidisciplinary planning, ICU post-op, avoid hypoxia/hypercarbia.

— COPD patient with increased sputum, dyspnea, wheeze scheduled for elective surgery tomorrow.

— Answer: Defer; treat exacerbation with steroids, bronchodilators, ± antibiotics; reschedule when stable.

— Patient scheduled for surgery in 6 weeks asks about quitting.

— Answer: Encourage cessation now; offer NRT or varenicline; cessation benefits regardless of timing.

Stem 1 — "Most appropriate pre-op test":

Stem 2 — Unexplained hypoxemia:

Stem 3 — Recent URI in a child:

Stem 4 — Lung resection workup:

Stem 5 — OSA and post-op respiratory failure:

Stem 6 — DNR for elective surgery:

Stem 7 — Pulmonary HTN pre-op:

Stem 8 — Active exacerbation:

Stem 9 — Smoking cessation timing:

Step 3 management: The recurring trap is over-testing. When the patient is stable and on appropriate therapy, the right answer is to proceed with optimization and education, not order PFTs/CXR/ABG.

One-Line Recap

Pre-operative pulmonary risk assessment is a clinical exercise — risk-stratify with ARISCAT or similar, optimize modifiable factors (smoking cessation, inhaler tune-up, CPAP, anemia, nutrition), avoid reflexive PFTs/CXR, and build a post-op bundle of incentive spirometry, early ambulation, multimodal opioid-sparing analgesia, and lung-protective ventilation to prevent atelectasis, pneumonia, and respiratory failure.

Top predictors: surgical site (thoracic/upper abdominal), age, low SpO₂, recent respiratory infection, anemia, hypoalbuminemia, functional capacity <4 METs.

Do NOT order routinely: CXR, PFTs, ABG. Order them only when history/exam raises a specific question they will answer or when planning lung resection.

Optimize, don't deny: ≥4-week smoking cessation, guideline-directed inhalers, CPAP for OSA, treat active exacerbations, vaccinate, correct anemia and nutrition, prehabilitation when feasible.

Anesthesia/surgical levers: regional anesthesia when possible, lung-protective ventilation, avoid residual neuromuscular blockade (quantitative TOF, sugammadex), multimodal opioid-sparing analgesia, laparoscopic when feasible.

Post-op bundle: incentive spirometry every 1–2 hours, early ambulation POD 0/1, head of bed ≥30°, immediate resumption of inhalers and CPAP, DVT prophylaxis, multimodal pain control.

High-yield ethics: required reconsideration of DNR for OR, explicit informed consent for high-risk patients, careful medication reconciliation and handoff at every care transition.

Board pearl: When the vignette describes a stable patient on appropriate therapy, the correct Step 3 answer is almost always clinical optimization and proceed, not additional testing — over-testing is the most reliable distractor in pre-op pulmonary questions.