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Related Subjects: Asthma |Acute Severe Asthma |Exacerbation of COPD |Pulmonary Embolism |Cardiogenic Pulmonary Oedema |Pneumothorax |Tension Pneumothorax |Respiratory (Chest) infections Pneumonia |Fat embolism |Hyperventilation Syndrome |ARDS |Respiratory Failure |Diabetic Ketoacidosis

Goal of treatment in acute exacerbation of COPD with Type 2 failure is to achieve a PaO₂ (> 7.0 kPa (52 mmHg)) without increasing PaCO₂ and acidosis, while identifying and treating the precipitating condition.

The fixed combination of an inhaled glucocorticoid and a LABA improves lung function, reduces the frequency and severity of exacerbations and improves the quality of life.

Background

• COPD (COPD) is a common, preventable and treatable disease
• There are persistent respiratory symptoms and airflow limitation

Causes

• Significant exposure to noxious particles or gases
• By far tobacco smoking is the most important
• Other environmental exposures such as biomass fuel exposure and air pollution may contribute.
• Severe hereditary deficiency of alpha-1 antitrypsin
• Commoner in females
• Lower socioeconomic status

Chronic Symptoms

• Chronic progressive dyspnoea, cough and/or sputum production
• Periods of acute worsening of respiratory symptoms, called exacerbations.
• Most patients often have significant concomitant chronic diseases, which increase its morbidity and mortality

Comorbidities seen

• Cardiovascular disease, Skeletal muscle dysfunction
• Metabolic syndrome, Osteoporosis, depression, anxiety, lung cancer.

Investigations

• Spirometry is required to make the diagnosis and a post-bronchodilator FEV1/FVC < 0.70 confirms the presence of persistent airflow limitation
• CXR will show changes in advanced disease

Exacerbation: Assess Patient

• Breathless, expiratory wheeze, sputum production, fatigue
• Using accessory muscles, pursed lips, cyanosis, tripod position.
• End stage COPD often cachexic and frail
• If in extremis or hypoventilating and peri-arrest then urgent anaesthetic help and critical care.
• Look at prior admissions and need for ITU or NIV

Investigations

• Blood: FBC,U&E,LFT, CRP. Elevated WCC and CRP may suggest infection
• CXR: look for consolidation, pneumothorax and typical emphysema changes
• ECG: Look for sinus tachycardia, RVH, P pulmonale, RBBB

Management first hour: Maximal medical care

• Get ABG to help assess severity and establish IV access. Are they in respiratory failure? Is the pCO₂ elevated.
• Start 24-28% O₂. Help patient into position of comfort. Aim for pO₂ > 8 Kpa with small rise in CO₂ < 1.5 KPa.
• Goal of treatment in acute exacerbation of COPD with Type 2 failure is to achieve a PaO₂ (> 7.0 kPa) without increasing PaCO₂ and acidosis, while treating the precipitating condition.
• Nebulisers: Beta agonist: Salbutamol[US Albuterol] 5 mg 4 hourly or Terbutaline 5-10 mg and Antimuscarinic: Ipratropium Bromide 0.5 mg 4 hrly
• It is useful to know at this stage if there are any advanced care plans that specify a ceiling to care.
• Start some slow IV fluids as often dehydrated and unable to drink. May need potassium as beta-agonists can cause hypokalaemia.
• Give Steroids either Prednisolone 30 mg OD for 7 days and/or Hydrocortisone 100 mg IV 8 hourly
• Furosemide 40-80 mg IV if fluid overload
• Aminophylline infusion Loading dose 5 mg/kg IV bolus over 20 mins unless on oral aminophylline or theophylline. ECG monitoring. Senior advice.
• In those who cannot have NIV consider Doxapram as a respiratory stimulant (1.5–4 mg/min infusion), which sometimes helps
• Antibiotics if any suggestions of bacterial infection (usual causes are Viral, H. Influenza, Strep Pneumonia, Moraxella Catarrhalis, Pseudomonas)
  • Amoxicillin 500 mg - 1 g TDS 5d
  • Doxycycline 100-200 mg PO od 5d
  • Clarithromycin 500 mg BD for 5d

Management 1-2 hours

• Check ABG and Assess for NIV. Consider need for NIV if pH < 7.35 and PCO₂ > 6 Kpa (45 mmHg). HCO₃ usually elevated.
• If pH < 7.26 and PCO₂ > 6 Kpa (45 mmHg) discuss with intensivists or respiratory team manage in HDU/ICU and short trial of NIV.
• If fails to improve then consider Intubation and ventilation and IPPV depending on known ceilings of care.
• Continue to Review and re-establish ceiling of care and discuss DNACPR
• Those who are dying should be palliated as compassionately as possible

NIV Settings

• This involves using a tight-fitting facial mask to deliver BiPAP ventilation support and so needs to be tolerated.
• Basic Criteria: Awake cooperative patient who can tolerate mask and protect airway. Able to cough. No facial burns or excess secretions.
• Settings: Inspiratory PAP 10 cmH₂O and Expiratory PAP 4 cmH₂O
• Targets: Increase IPAP to 20 cmH₂O by 5 cms every 10-20 minutes. Ensure full face mask. Give O₂ to get SaO₂ 88-92%. Give regular nebulisers and Check for leaks in mask
• Check ABG after 1 hour and after every change in parameters. Be ready to escalate to Intubation
• Continue for 16 hrs day 2 and 12 hrs day 3. Ensure it continues overnight. Stop Day 4 may be possible.

On Discharge

• Respiratory nurse follow up with education, advice, contacts, rehabilitation, Smoking cessation, Inhaled steroid + LABA
• Smoking cessation is key. Pharmacotherapy and nicotine replacement reliably increase long-term smoking abstinence rates. The effectiveness and safety of e-cigarettes as a smoking cessation aid is uncertain at present
• Prescribe LABA: Long-acting beta-agonist. Formoterol and salmeterol are twice-daily LABAs that significantly improve FEV1 and lung volumes, dyspnoea, health status, exacerbation rate and the number of hospitalizations, but have no effect on mortality or rate of decline of lung function
• Prescribe LAMA: these block the bronchoconstrictor effects of acetylcholine on M3 muscarinic receptors expressed in airway smooth muscle. Tiotropium, a long-acting antimuscarinic agent
• Inhaled corticosteroids if frequent exacerbations
• Vaccinations: Influenza, Pneumococcal
• Advanced Care planning when severe

Management of Milder cases: Criteria for discharge

• May go home on Amoxicillin 500 mg 8h for 1 week
• Prednisolone 30 mg daily for 2 weeks
• Clinically stable condition and have had no parenteral therapy for 24 hours
• No evidence of respiratory failure or cor pulmonale.
• Inhaled bronchodilators are required less than four-hourly
• O₂ delivery has ceased for 24 hours (unless home oxygen is indicated)
• If previously able, the patient is ambulating safely and independently, and performing activities of daily living
• The patient is able to eat and sleep without significant episodes of dyspnoea
• Able to cope at home. The patient or caregiver understands and is able to administer medications
• Follow-up and home care arrangements (e.g., home oxygen, home-care, Meals on Wheels, community nurse, allied health, GP, specialist) have been completed.

Assess for Home O₂ Criteria

• In patients with severe resting chronic hypoxaemia, long-term oxygen therapy improves survival.
• Must be non-smoker, compliant.
• PaO₂ >=7.3 kPa (55 mmHg) or SaO₂ =88%, +/- hypercapnia confirmed twice over a 3-week period
• PaO₂ 7.3 kPa (55 mmHg) to 8.0 kPa (60 mmHg), or SaO₂ of 88%, if evidence of pulmonary hypertension, CCF, or polycythaemia (haematocrit > 55%)

References

• Chronic obstructive pulmonary disease in over 16s: diagnosis and management. NICE guideline [NG115] Published date: 05 December 2018 Last updated: 26 July 2019
• Global Initiative for Chronic Obstructive Lung Disease Global Initiative 2017