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Home , Respiratory failure, Wheeze

Approach to type 2 Changing Nature of NIV

• Not longer just the traditional COPD patients • Increasingly – Obesity – Neuromuscular – • 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 • • 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 Response to demand

• Increase depth of • Use Reserve volume • Increase rate of • General increase in minute ventilation • More 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 • 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 – /Pulmonary oedema – Hypoxia • Superimposed problems – Metabolic – 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- • ECG- • Bloods- Metabolic, BM, TSH Simple Measures

• Reduce work of breathing • Sit them up- 45 degree angle • Good clearance • Enough oxygen- 88-92%? hypoxia will kill you first • Avoid resp depressants • Max cardiac output Treat underlying cause

• – Reduces air trapping and V/Q mismatch – Lots of nebs, magnesium, aminophyline • – 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 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 • 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 • – Just don't • – 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 • 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 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