COPD & Respiratory Failure

1. COPD & Respiratory Failure Dr SamirSahu Sr Consultant Critical Care & Pulmonology Apollo Hospitals, Bhubaneswar.

2. Introduction • The average patient withCOPD experiences two episodes of AECOPD per year, • 10% ofthese episodes require hospitalizationSullivan SD,Ramsey SD, Lee TA.Chest2000

3. COPD exacerbation • Type 1: severe - worsening dyspnea, - increase in sputum purulence - increase in sputum volume. Washington manual of critical care 2008

4. Initial evaluation • history, • physical examination, • basic laboratory tests, • chest X ray • ABG.

5. Clinical Picture • Signs of muscle fatigue • Paradoxical breathing (an inward motion of the upperabdominal wall with inspiration) • Respiratory alternans (acyclic alternation between abdominal and rib cage breathing), • suspicion of impending respiratoryfailure.

6. COPD-Respiratory Failure • Oxygenation Failure-V/Q mismatch • Ventilatory Failure -Excessive Respiratory Load -Hyperinflation -Inadequate Inspiratory Muscle Endurance -Length-Tension -Force-Velocity -Fatigue • PO2<50, PCO2>50

7. AE-COPD- Treatment BRONCHODILATORS • Rapidly acting B2 agonist & anticholinergic by Aerosol -Ipratropium 0.25-0.5mg(60-90m) -Salbutamol 2.5-5mg (30-60m) -Terbutaline 5-10mg (30-60m) • Theophyline(if no response) -Aminophyline-0.5mg/Kg/hr inf.

8. AE-COPD-Treatment OXYGEN THERAPY • O2 inhalation by nasal cannula/face mask • Maintain SpO2 88-93%(PO2 55-60) • Monitor PCO2(may increase in 26%) • Repeat ABG in 60min. • SpO2 monitoring may be satisfactory if pH & PCO2 are normal & SpO2 does not fall • Continue O2 during Nebulization

9. OXYGEN THERAPY • OXYGEN CYLINDER -A - 700 lit (2lit/m) - 6hrs -B - 1500 lit (2lit/m) - 11hrs -C - 5000 lit (2lit/m) - 40hrs • PIPED OXYGEN • OXYGEN CONCENTRATOR (5L/m) • - Flowmeter,

10. AE-COPD-Treatment CORTICOSTEROIDS • Parenteral for first 72hrs (methyl-prednisolone 125mg IV 6hrly) • Followed by Oral Corticosteroid • Gradually taper off over 7-14day • Inhaled steroids are not appropriate MacIntyre NR. Respir Care 2006

11. AE-COPD-Treatment ANTIBIOTICS • Increased Breathlessness • Increased Sputum Volume • Purulent Sputum • pH < 7.35 • 7 day course of appropriate Antibiotic • Treating an AECOPDepisode early improves the speed of functional recovery. Saint S, et al: a meta-analysis. JAMA 1995

12. AE-COPD-Treatment Clearance of Secretion • Bronchodilators, Antibiotics & Corticosteroids decrease Secretions. • Expectorants & Mucolytics -No role, may improve symptoms. • Chest Physiotherapy -Ineffective, perhaps detrimental.

13. Indication of Ventilatory Support • Deterioration in spite of Medical treatment. • Moderate to severe dyspnoea • Increasing respiratory distress - RR>24, - accessory muscle use, - paradoxical breathing • Respiratory Acidosis (pH < 7.37) • Hypercapnia (pCO2 >55mm of Hg) • Severe deterioration in Mental status • PaO2/FiO2 < 200 Peter et al.Ann Intern Med. (2004)

14. Ventilation in COPD • Non Invasive Ventilation • Invasive Ventilation as rescue intervention • Invasive Ventilation as first choice • NPPV to speed up liberation from ventilation

15. AE-COPD- NPPV SELECTION CRITERIA • Hypercapnic/Hypoxemic Respiratory Failure unresponsive to conservative treatment • Normal Bulbar function • Ability to clear secretions • Haemodynamically stable • Ability to cooperate with treatment • No facial trauma & upper airway injury

16. Non Invasive Positive Pressure Ventilation in AECOPD • The two largest studies ofNPPV in AECOPD showed that NPPV reduced the need for invasivemechanical ventilatory support. Peter et al – a meta-analysis update. Crit Care Med 2002 Lightowler JV. Cochrane sys review & meta-analysis.BMJ 2003

17. NPPV in COPD • Recent studies demonstrate that outcomes of severe COPD exacerbations are no worse if treated with NPPV than with endotracheal intubation, indicating thatan initial trial with NPPV is not deleterious, even in severely ill COPD patients (hypercapnic coma). Scala R et al, Chest 2005 Gonzalez D et al, Chest 2005 Conti G et al, Intensive Care Med 2002

18. Possible NPPV Locations • Pre-Hospital Setting • Emergency Department • ICU • Step-Down Unit • General Wards • Long-Term Acute-Care Hospitals

19. NPPV ventilator days - KHL

20. NPPV - Predictors of Failure • Air leaking, Lack of compliance & tolerance Clinical Condition of patient – high Apache II >29 • Asynchrony • Copious secretions • GCS <11 • pH < 7.25 • Respiratory rate >35/min, high baseline HR • Presence of Pneumonia Change in pH in first hour of NPPV Ambrosino, Thorax 1995, Phua, Inten Care Med 2005, KhilnaniInd J Crit Care Med 2006

21. NPPV - Failure • The failure rate of NPPV in AECOPD is as high as50% Jolliet P et al. Crit Care Med 2003 • 20% of COPD AE experience a new episode of Respiratory Failure. Mortality is 91% with continued NPPV compared to 52.6% in those who are intubated & ventilated Moretti et al (2000), Thorax

22. NPPV Failure • The decision to discontinueNPPV and proceed to invasive mechanical ventilatory supportis a clinical one usually driven by progressive respiratoryacidosis and signs of patient fatigue/discomfort during NPPV. • Mechanical Ventilation allow the patient to improve sufficiently to take advantage of NPPV which was ineffective earlier

23. NPPV Outcome-COPD (2000-2010) • Success – 159/266 (60%) - mean PCO2-71(IQR 54.5-90.6), mean pH-7.295 • Failure - 107/266 (37.5%) – mean PCO2-82(IQR 56.8-107), mean pH-7.285 (Pneumonia 10, Sepsis 5, ARF 5, TBs 5) • Intubated - 53 • LAMA – 21 • Death – 81 (30.45%) - DNI 36, Cardiac 8, Withdrawal 5, Refusal 1, delay in intubation 2.

24. Invasive Ventilation as first-line intervention • Respiratory arrest • Unable to fix interface • Extreme Obesity • Unable to protect airway • Need for airway suction for copious & tenacious secretions

25. Invasive MV – Minute Ventilation • Reduce tidal volumes (e.g., 5–7ml/kg) to protect the lung in AECOPD. • A high peak pressure, even in the presence of acceptable plateaupressures, should be avoided. • Permissive hypercapnia. Accepting pH values in the 7.0–7.1 range mayhave little clinical effect on the patient and may be beneficialif the reduced volumes and pressures reduce the risk of VILI Kavanaugh BP. Am J RespirCrit Care Med 2005

26. Dynamic Hyperinflation & Auto-PEEP • To avoid intrinsic PEEPbuild up due to patient tachypnea, moderate sedationmay be required. • Reducing PEEPi requires reductions inany or all: -reducing minute ventilation(permissivehypercapnia) -a shorter I/E that lengthens the expiratory time -reductions in airway resistance using pharmacologic agents. • If the PEEPi is causing a significant ventilator breath–triggeringload on the patient, judicious amounts of applied circuit PEEPcan equilibrate expiratory pressures and thereby reduce thistriggering work.RanieriVM,et al. Intensive Care Med 1995

28. Intrinsic PEEP (PEEPi) Pressure PEEPi PEEPe Time

29. ModeVolume Control Automode Admitpatient Nebulizer Status Alarmprofile 12-25 15:32 Recording Save Trends 60 cmH2O Ppeak 52 Pplat Pmean 10 i Basic I:E PEEP 8 70 l/min RR 3 O2 100 Vee 5 Quickstart I:E 1:4.0 Menu 700 ml MVe 3.0 Mainscreen MVi 2.8 VTi 401 VTe 371 . Additionalsettings Additionalvalues ! Startbreath O2breaths Exp.hold Insp.hold 29  Charles Gomersall 2003

30. Invasive MV • Endotrachealtubessignificantly reduce aerosol delivery, doses usually are increasedthree- to fourfold (or aerosolized continuously) to ensure adequatedrug effectiveness. • Assessment of airway pressures (peak toplateau gradients) or flow–volume patterns can be usedto monitor bronchodilator effectiveness.

33. KHL Data – Mechanical Ventilation in AECOPD (2000-2008)(92cases) • Invasive as first choice – 65 • Rescue Ventilation after NPPV failure – 27 • Median pH at the time of intubation: 7.176 (IQR range: 7.113-7.255) • Median PCO2 at the time of intubation: 115.6 (IQR range:83.8-138.5) • Median Duration of invasive ventilation: 6 days (IQR range:3-10 days) • Survived – 64(70%),LAMA – 6(6%), Death – 22(24%)

34. Invasive MV - Weaning • Dailyspontaneous breathing trials should be performed as patientsrecover, and patients should be managed with comfortable formsof assisted ventilation (e.g., pressure support, pressure assist,or proportional assist) in between the spontaneous breathingtrials. • Having a well defined protocol Vitacca M et al. Am J RespirCrit Care Med 2001

35. Weaning from Mechanical Ventilation • NPPV may be used to expedite weaning from invasive ventilation in uncomplicated cases of COPD who fail a trial of spontaneous breathingNava S, et al. Ann Intern Med 1998 GiraultC, et al. Am J RespirCrit Care Med1999 • Patients failing to wean from MV should be evaluated for critical care myo-neuropathy Amaya-Villar R et al. Intensive Care Med 2005

36. COPD - Wean • Total - 60 cases • Success - 39 • Failure – 18 • DNI – 6, Withdrawal - 1 • Death - 10

37. NPPV weaning duration – KHL42/92

38. Noninvasive Ventilation Use for COPD Linked With Lower Death Rates • The first examination of the patterns and outcomes of NPPV treatment for acute exacerbations of COPD in clinical practice nationwide. • The authors concluded that there was a more than 4-fold increase in NPPV use accompanied by a decrease in IMV use in the 10 years examined in patients with COPD. The researchers also noted that although mortality rates decreased overall, the rates increased for patients who were transitioned from NPPV to IMV. • Although NPPV is shown to be efficacious for the treatment of acute exacerbations of COPD, the authors cautioned that patients at high risk for conversion to IMV should be closely monitored with a plan for early intervention if there is no improvement. Am J RespirCrit Care Med. Published online October 21, 2011

39. Outcomes of AECOPD • AECOPD episodeshave been shown to accelerate FEV1 decline, to increase mortality(AECOPD episodes are the most common cause of death in COPD),and to have a profound influence on the decline in quality oflife scores • One large survey found an in-hospital mortality rate of 11%and 1-year mortality rate of 43% in patients with COPD admittedfor acute exacerbations . Another recent study found a similarin-hospital mortality rate (8%) and 1-year mortality rate (23%). These mortality figures are much higher for patients requiringICU admissionConnors AF Jr, et al. Am J RespirCrit Care Med 1996

40. Outcome of AECOPD • In a large, multicenter study,the need for mechanical ventilation did not influence outcomein patients with COPD admitted to an ICU. • However, therisk for rehospitalization and reintubation for patients withCOPD is increased markedly after an episode of respiratory failurerequiring mechanical ventilation SeneffMG, et al. JAMA 1995

41. Disease Trajectory of a Patient with COPD Stable Phase Steady decline in FEV1

42. Palliative Care & Do not Intubate Patients • NPPV offers an effective, comfortable & dignified method of supporting patients with end stage disease & acute respiratory failure • If the patient and/or family desire prolonged survival, then use should be reserved primarily for COPD and congestive heart failure patients. • On the other hand, if the goal is to palliate, to relieve dyspnea, or to delay death so that affairs can be settled, then NPPV can be used for these as well as other diagnoses. • However, it should be reassessed frequently and stopped if the goal of palliation is not being met.

43. Summary • Respiratory failure in COPD needs proper initial clinical assessment & ABG for assessment of severity & decide modality & location of treatment. • All patients with severe respiratory failure in COPD should be given a trial of NPPV. • NPPV is more labour intensive & needs frequent assessment & earlier detection of failure of NPPV. • If NPPV fails patient should be intubated & mechanically ventilated early & promptly.

44. Summary cont. • All measures should be taken to prevent harm to the patient during mechanical ventilation by using lower tidal volumes, & looking for dynamic hyperinflation(autopeep). • Weaning from Mechanical ventilation should be speeded up by using NPPV.

45. THANK YOU