Approach to type 2 Respiratory Failure Changing Nature of NIV • Not longer just the traditional COPD patients • Increasingly – Obesity – Neuromuscular – Pneumonias • 3 fold increase in patients with Ph 7.25 and below Impact • Changing guidelines • Increased complexity • Increased number of patients • Decreased threshold for initiation • Lower capacity for ITU to help • Higher demands on nursing staff Resp Failure • Type 1 Failure of Oxygenation • Type 2 Failure of Ventilation • Hypoventilation • Po2 <8 • Pco2 >6 • PH low or bicarbonate high Ventilation • Adequate Ventilation – Breathe in deeply enough to hit a certain volume – Breathe out leaving a reasonable residual volume – Breath quick enough – Tidal volume and minute ventilation Response to demand • Increase depth of respiration • Use Reserve volume • Increase rate of breathing • General increase in minute ventilation • More gas exchange Failure to match demand • Hypoventilation • Multifactorial • Can't breathe to a high enough volume • Can't breath quick enough • Pco2 rises • Po2 falls Those at risk • COPD • Thoracic restriction • Central • Neuromuscular • Acute aspects – Over oxygenation – Pulmonary oedema Exhaustion • Complicates all forms of resp failure • Type one will become type two • Needs urgent action • Excessive demand • Unable to keep up • Resp muscle hypoxia Exhaustion • Muscles weaken • Depth of inspiration drops • Residual volume drops • Work to breath becomes harder • Spiral of exhaustion • Pco2 rises, Po2 drops Type 2 Respiratory Failure Management Identifying Those at Risk • Pre-existing conditions • Acute factors – Bronchoconstriction/Pulmonary oedema – Hypoxia • Superimposed problems – Metabolic acidosis – Low cardiac output Recognising the problem • Pick them up early- plan escalation • Confusion • Flap • Signs of exhaustion • Agitation, • High HR, • High BP • Sweaty Why are they in type two? • Don’t assume • Multifactorial • Examination- wheeze, opiods, oedema • EARLY x-ray- Pneumothorax • ECG- Myocardial infarction • Bloods- Metabolic, BM, TSH Simple Measures • Reduce work of breathing • Sit them up- 45 degree angle • Good sputum clearance • Enough oxygen- 88-92%? hypoxia will kill you first • Avoid resp depressants • Max cardiac output Treat underlying cause • Bronchospasm – Reduces air trapping and V/Q mismatch – Lots of nebs, magnesium, aminophyline • Pleural disease – drain pneumothorax/effusions • Cardiac output – fluids/inotropes Non Invasive Ventilation • Augmenting patients breathing without an ET tube • Maximises Inspiratory volume (maintains tidal volume) • Stops airway collapse • Can control rate of breathing • Reduces the work of breathing NIV • Bilevel positive pressure ventilation • Maintaining the volume in the lungs between two ideal levels • Applies pressure at maximum ventilation (ipap) • Applies pressure at maximum expiration to splint airways (epap) NIV- Does it work • Up to 70% reduction in work of breathing • Improved mortality over invasive ventilation • Reduced – Invasive ventilation – Hospital mortality – Length of stay • Mortality static over 10 years • Effective in the elderly Role of NIV • Support tiring patient at early stage • Treat type two resp failure to avoid invasive ventilation • Ceiling of treatment when invasive ventilation is inappropriate • Palliation Timing of NIV • Is the PH <7.35 • Is the Pco2 >6.5 (i.e. do they have a respiratory acidosis) • Is their oxygen appropriate for the patient? • Have you treated the correctable factors for 30-60mins? • If so consider starting NIV Timing of NIV • Maximise for an hour? – Mild to Moderate Acidosis – COPD – 20% will improve • Delay of more than hour is harmful • Delay in other patient groups – Poorer outcomes Timing of NIV • Maximise one hour if – Simple copd exacerbation – Ph 7.25 or above – Capacity for review in one hour – Capacity for immediate initiation of NIV – No signs of exhaustion Contra indications to NIV • Very few – No longer • Low ph • Low GCS • Mainly indications for Invasive ventilation • Facial injuries • Poor upper airway • Uncontrolled bowel obstruction- NG tube Who should be invasively ventilated • 1) Reversible pathology • 2) Remains active • 3) Reasonable muscle bulk And don’t forget • 4) Patients wishes • Contact early!! Decision Time • Is this patient more appropriate for consideration for immediate invasive ventilation? • Poor upper airway • very hypoxic • severe sepsis • bowel obstruction • Not PH or decreased GCS Decision Time • Is the patient suitable for NIV but should be considered for ITU if fails NIV? – Protect respiratory muscles – Prevent VAP – Protect against muscle wasting – Protect against ITU Psychosis – Patients do better on NIV NIV as a Trial • Best done in ITU – Ph < 7.15 – Decreased GCS – Confusion – Pneumonia • Delayed intubation = increased mortality • Make decisions early and be proactive Special Circumstances • Pulmonary Oedema – Works – May not keep them alive long term • Asthma – Just don't • Pneumonia – If not for ITU Where to NIV? • Initiation shouldn’t be delayed • Specialist Unit • Appropriate staffing – Trained Nurses – Capacity to do regular obs – 2-1 nursing – Level 2-3 Setting up • Mode – Bilevel/bipap/pressure support • Ipap – High pressure used to fill the lung • Epap – Low pressure use to keep lungs open • Difference Ipap and Epap = Tidal volume IPAP Vs EPAP • IPAP controls depth of ventilation • Bigger gap between ipap and epap = deeper ventilation • Therefore IPAP controls PCO2 • EPAP overcomes stiff and noncompliant lungs and airways • EPAP and help oxygenation Rule of thumb • Initial settings • Start IPAP -15 EPAP – 3 • Review patient clinically. Is their chest rising? Is their heart rate and BP improving? Are they working less hard to breath? • If not titrate up IPAP in 2cm increments Rule of thumb • Are their sats low? • Is their chest barely moving? • Is the apnoea alarm buzzing at you? • If any of yes to any of these increase both the EPAP and IPAP by 2 increments. • Once your happy repeat ABG in 1 hour Oxygen • Continue to aim 88-92% • Supply oxygen through mask or tubing • Difficult to predict how much they need • Machine looses a lot of oxygen • Patient is ventilating better • Start high and titrate down Failing on NIV • High respiratory rate, • High BP • High pulse • Agitation • Working hard to breath with accessory muscles • Sweating Pco2 not coming down • Inadequate ventilation • Assess airway • Sit patient up • Treat underlying cause • Increase IPAP • Repeat ABG Po2 Poor • Maximise ventilation • Increased inspired Oxygen • Increase EPAP and IPAP until chest rising • Treat underlying cause • Reassess for pneumothorax/mucus plugging Conclusion • Changing nature of patients • Reduce work of breathing • Early planning- ?ITU • Early initiation- ?wait until acidotic • Very few contraindications .