COPD exacerbation

Background

• Airflow limitation (FEV1:FVC < 0.70) that is not fully reversible
  • Encompasses chronic bronchitis (85%) and emphysema (15%)
• Acute exacerbations due to incr V/Q mismatch, not expiratory airflow limitation

Precipitants

1. Infection (75%)
   1. 50% viral, 50% bacterial
2. Cold weather
3. B-blockers
4. Narcotics
5. Sedative-hypnotic agents
6. PTX
7. PE

Diagnosis

• Increase in cough, sputum, or dyspnea
• Hypoxemia
  • Tachypnea, tachycardia, HTN, cyanosis, AMS
• Hypercapnia

Differential Diagnosis

1. Ashtma
   1. More likely in younger pt (<50yo)
2. CHF
   1. Can coexist w/ COPD
   2. Orthopnea, interstitial edema more c/w CHF
   3. BNP >500 very likely to be CHF
3. PE
   1. 20% of pts w/ severe COPD exacerbation of unclear trigger have a PE
4. ACS
5. PTX
   1. COPD is major risk factor for PTX
6. PNA
   1. Frequently coexists w/ COPD exacerbation

Work-up

1. VBG/ABG
   1. Perform if SpO2 <90% or concerned about symptomatic hypercapnia
2. Peak flow
   1. <100 indicates severe exacerbation
3. CXR
   1. Consider if concerned for PNA or CHF
4. Sputum culture
   1. Usually not indicated except for pt w/ recent antibiotic failure

1. 1. 1. Risk factors for pseudomonas infection
         1. Recent hospitalization (>2 days within previous 3 months)
         2. Frequent abx tx (>4 courses w/in past year)
         3. Severe underlying COPD (FEV1 < 50% predicted)
         4. Previous isolation of pseudomonas

Treatment

1. O2
   1. Maintain PaO2 of 60-70 or SpO2 90-94%
   2. If unable to correct hypoxemia with a low FiO2 consider alternative diagnosis
   3. Adequate oxygenation is essential, even if it leads to hypercapnia
   4. If hypercapnia leads to AMS, dysrhythmias, or acidemia consider mechanical ventilation
2. Albuterol/ipratropium
3. Steroids (no difference in efficacy between PO and IV)
   1. Duration = 7-10d (no tapering required)
   2. Oral: Prednisone 40-60mg daily
   3. IV: Methylprednisolone 60-125mg BID-QID
4. Antibiotics
   1. Indicated for:
      1. Increased sputum volume or change in color
      2. Fever
      3. Suspicion of infectious etiology of exacerbation
5. Noninvasive ventilation (CPAP or BiPaP)
   1. CPAP: start at low level and titrate up to max 15
   2. BiPAP: Start IPAP 8 (max 20), EPAP 4 (max 15)
   3. Contraindications:
      1. Uncooperative or obtunded pt
      2. Inability to clear secretios
      3. Hemodynamic instability
6. Mechanical ventilation
   1. Indications
      1. Severe dyspnea w/ use of accessory muscles and paradoxical breathing
      2. RR>35 bpm
      3. PaO2 <50 or PaO2/FiO2 <200
      4. pH <7.25 and PaCO2 >60
      5. Altered mental status
      6. Cardiovascular complications (hypotension, shock, CHF)

Outpatient

1. If pt has risk factors (Age >65, cardiac disease, >3 exacerbations per year):
   1. Levofloxacin/moxifloxacin OR amox/clavulanate
2. No risk factors
   1. Azithromycin OR doxycline OR TMP/SMX
3. Pseudomonas risk factors (see above)
   1. Ciprofloxacin

Maintenance

1. B-agonist
   1. Short:albuterol 90µg/inh 1-2 q4-6h prn; neb 2.5mg q4-6h prn
   2. Long: Salmeterol 50µg/inh 1 bid
      1. Formoterol MDI 12µg/INH 1 bid; neb 20µg bid
      2. Arfomoterol neb 15µg bid
2. Anticholinergic
   1. Short: ipratriopium 17µg/INH 2xINH 4x/d up to 12; neb 0.5mg q6-8h
   2. Long: tiotropium 18µg/INH 1xINH qam
3. Steroids (inhaled)
   1. Fluticasone (dry powder) 250µg/INH 1-2 bid; (aerosol) 220µg 1-2INH bid
   2. Budesonide 160µk 2 inh bid
   3. Beclomethasone 80µg/inh 2INH bid
   4. Mometasone 220µg/INH 1-2INH bid
4. Combination
   1. Albuterol-Ipratropium 90/18 2INH 4xd up to 12
   2. Advair Diskus = Fluticasone-salmeterol (dry powder): 250/50 1INH bid
   3. Budesonide-Formoterol: 160/4.5 2INH bid
5. Home O2
   1. Indicated if PaO2 < 55mmHg or O2 Sat < 88% RA
   2. Goal is 18h/day including sleep with flow rate that maintain sat > 90%

Inpatient

1. Pseudomonas risk factors:
   1. Levofloxacin PO or IV OR cefepime IV OR Ceftazadine IV OR pip-tazo IV
2. No pseudomonas risk factors:
   1. Levo/moxifloxacin PO or IV OR CTX IV OR cefotaxime IV
3. Consider oseltamivir during influenza season

Disposition

Consider hospitalization for the following:

1. Inadequate response of symptoms to outpatient management
2. Inability to eat or sleep due to symptoms
3. Changes in mental status
4. Uncertain diagnosis
5. High risk comorbidities (e.g. PNA, CHF, renal failure)

Source

• NEJM 4/10
• UpToDate
• Tintinalli