18/Oct/2005Dr. David P. Breen1 COPD- Burden of Disease Initial management of an acute exacerbation

18/Oct/2005Dr. David P. Breen2 Definition COPD is a disease state characterized by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. Symptoms, functional abnormalities, and complications of COPD can all be explained on the basis on this underlying inflammation and the resulting pathology

18/Oct/2005Dr. David P. Breen3

18/Oct/2005Dr. David P. Breen4 Lung Function decline

18/Oct/2005Dr. David P. Breen5  Spirometry is the GOLD Standard for the diagnosis of COPD

18/Oct/2005Dr. David P. Breen6 Exacerbations of COPD  Acute exacerbations of COPD present as a worsening of a previously stable condition  Important symptoms include  Increased sputum purulence  Increased sputum volume  Increased dyspnoea  Increased wheeze  Chest tightness  Fluid retention

18/Oct/2005Dr. David P. Breen7 Exacerbation  A new respiratory event or complication superimposed upon established disease  New events  Pneumonia  Pneumothorax  LVF/ Pulmonary Oedema  Lung Cancer  Upper airway Obstruction

18/Oct/2005Dr. David P. Breen8 Acute exacerbation of COPD 1.Airflow Obstruction a)Dyspnoea b)Wheeze c)Chest tightness 2.Respiratory Failure a)Hypoxia i.Dyspnoea, tachypnoea, cyanosis, confusion b)Hypercapnia i.Warm hands, dilated veins, tachycardia, bounding pulse, flapping tremor, chemosis, papilloedema, confusion, agitation 3.Cor pulmonale a)Loud P2, RV (L Parasternal Heave), raised JVP, peripheral oedema 4.Infection a)Increased sputum volume/purulence, fever, raised WCC

18/Oct/2005Dr. David P. Breen9 Investigations  Full Blood Count  Renal Profile  Arterial Blood Gas  Chest X-Ray  Pneumonia  Bronchiectasis  Pneumothorax  LVF  Spirometry prior to discharge

18/Oct/2005Dr. David P. Breen10 TREATMENT  Airflow Obstruction  Bronchodilators- Salbutamol, ipratropium  Corticosteroids  Respiratory Failure  See later  Cor Pulmonale  Daily weight, accurate input/output chart  Diuretics  Monitor renal function carefully  Infection  Antibiotics  physiotherapy

18/Oct/2005Dr. David P. Breen11 Acute Respiratory Failure ABG Normal PO KPa Normal PCO KPa Type 1 Failure PO 2 PCO2 N or Type 2 Failure PO 2 PCO2

18/Oct/2005Dr. David P. Breen12  Normally we breath mainly in response to raised PCO 2 In Type 1 failure, this response is maintained High O 2 is safe  In COPD, there is usually chronic CO 2 retention The brain gets tired of responding to the raised PCO 2 The main stimulus to breathe is then a decreased PO 2

18/Oct/2005Dr. David P. Breen13 So, How much O 2 should we give?

18/Oct/2005Dr. David P. Breen14 In Type 2 Respiratory Failure PO 2 Hypoxic DriveSaO 2 O 2 Delivery 7.5maintained90% adequate/good <7maintained<90%poor 5.0maintained<70% dangerously low 7.5maintained 90% adequate/good >8decreasing>90%good 10very poor95%good

18/Oct/2005Dr. David P. Breen15 Therefore Look first at PO 2 Maintain PO 2 around (SaO %) Do not be afraid to give enough O 2 to achieve this Do not push PO 2 above this – very little extra delivery of O 2 to all tissues and loss of hypoxic drive now becomes a problem Monitor PCO 2 and clinical condition If PCO 2 elevated or clinical condition poor Consider N.I.V Start with 24-28% and titrate upwards Monitor Sats and ABG

18/Oct/2005Dr. David P. Breen16 But remember : Cigarettes are the main culprit!!

18/Oct/2005Dr. David P. Breen17

18/Oct/2005Dr. David P. Breen18 Non-Invasive Ventilation:

18/Oct/2005Dr. David P. Breen19 Selection Criteria  Respiratory distress  Moderate to severe dyspnoea  Accessory muscle use  Paradoxical movement of abdominal muscles  pH 6kPa  Respiratory rate >25breaths/min  At least two criteria should be present

18/Oct/2005Dr. David P. Breen20 Exclusion Criteria (Absolute)  Respiratory Arrest situation  Cardiorespiratory instability  Hypotension  Arrhythmia  Myocardial infarction  Uncooperative patient  Recent facial, oesophageal or gastric surgery

18/Oct/2005Dr. David P. Breen21 Exclusion Criteria (Absolute)  Craniofacial trauma or burns  High aspiration risk  Absent gag reflex  Inability to manage secretions  Fixed anatomical abnormalities of the nasopharynx

18/Oct/2005Dr. David P. Breen22 Relative Contraindications  Extreme anxiety  Massive obesity  Copious secretions  Adult Respiratory distress syndrome-ARDS  American Respiratory Care Foundation.

18/Oct/2005Dr. David P. Breen23 Complications  Local damage related to mask/strap pressure  Gastric distension  Eye irritation  Sinus pain  Nasal congestion  Barotrauma  Air leaks  Adverse Haemodynamic effects rare  Nosocomial pneumonia rare

18/Oct/2005Dr. David P. Breen24 Predicting Poor Outcome  Higher APACHE II score (15 Vs 20)  Acute physiological and chronic health evaluation  Lower pH in those who failed  7.22 Vs 7.28 Ambrosino et al  Lower FVC  Presence of pneumonia  Soo Hoo et al Crit Care Med 1994

18/Oct/2005Dr. David P. Breen25 Suggested settings  NIPPY  Aim for IPAP of 20  Normal breathing= 1sec insp, 2sec exp,will probably need to be shortened  Set trigger low eg. 0.5 = less effort required by patient  BIPAP  Suggest starting with IPAP 10 or 12  May increase to 20 or higher  Suggest starting with EPAP of 4  Never use less than EPAP of 4 = CO2 rebreathing  May increase EPAP to 6, seldom require higher

18/Oct/2005Dr. David P. Breen26 Effectiveness  Significant decrease in mortality (9% Vs 29%) Brochard et al NEJM 1995

18/Oct/2005Dr. David P. Breen27 Effectiveness  Significant decrease in ICU length of stay (13 Vs 32 days) Wysocki et al Chest 1995  Significant decrease in hospital length of stay (23 Vs 35 days) Brochard et al NEJM 1995