BiPAP use for acute hypercapnic respiratory failure Indications for BiPAP Contraindications for BiPAP BiPAP setup BiPAP monitoring

Absolute: Mask Oxygenation COPD: Severe facial deformity Aim 88-92% in all patients pH <7.35, pCO2 >6.5kPa, RR>23 Full face mask (or own if home user of NIV) Facial burns Size mask appropriately If high oxygen need or rapid desaturation If persisting after broncho-dilators Fixed upper airway obstruction and controlled oxygen therapy on disconnection from BiPAP consider IMV Note: home style ventilators CANNOT Initial Pressure Settings (S/T mode) provide >50% inspired oxygen Relative: EPAP: 4 (or higher if OSA known/expected) pH <7.15 (pH<7.25 and additional adverse feature) ECG IPAP in COPD/OHS/KS :15 (or 20 if pH <7.25) GCS <8 Continuous ECG monitoring for HR >120, Confusion/agitation dysrhythmia, or known cardiomyopathy Up titrate IPAP over 10-30 mins to IPAP 20-30 to Cognitive impairment achieve adequate augmentation of chest/abdo BiPAP settings Neuromuscular disease: (warrants enhanced observation) Documented as per BSUH NIV pathway. Respiratory illness with RR>20 movement and reduce RR if usual VC <1L even if pCO2 <6.5 IPAP should not exceed 30 or EPAP 8 * without Consider aim for tidal volume (TV) Or Indications for referral to ICU: expert review to avoid under/over ventilation. pH <7.35 and pCO2 >6.5kPa AHRF with impending respiratory arrest Aim for a leak of 25-40. IPAP in NMD :10 (or 5 above usual setting) Adjust mask as required. BiPAP failing to augment chest wall movement or

reduce pCO2 Backup Rate Backup rate of 10 Inability to maintain sats > 85-88% on BiPAP (set appropriate inspiratory time) If RR inadequate consider increasing Red Flags Timed breaths Backup rate until relating pH<7.25 on optimal BiPAP settings Obesity: (patient not spontaneously breathing) spontaneous rate improves RR persisting >25 pH <7.35, pCO2 >6.5kPa, RR>23 to timed New onset confusion or patient distress Or Need for IV sedation or adverse features indicating I:E ratio breaths Requiring EPAP > 6 Daytime pCO2 >6.0 and drowsy/ need for closer monitoring and/or possible difficult COPD 1:2 or 1:3 reduced GCS intubation as in OHS, NMD. only Timed breaths (patient not spontaneously OHS, NMD & CWD 1:1 breathing)

Inspiratory Time Actions COPD 0.8-1.2s Check synchronisation, mask fit, exhalation OHS, NMD & CWD 1.2-1.5s port : give physiotherapy, bronchodilators, consider anxiolytic BiPAP not indicated Prescribe BiPAP Use BiPAP for as much time as possible CONSIDER IMV BiPAP must be prescribed by the treating in initial 24 hours. Asthma/Pneumonia clinician using BSUH ‘NIV pathway’ Wean BiPAP depending on tolerance and ABGs Refer to ICU for consideration in next 48-72 hours. IMV if increasing respiratory rate/distress Contact CCOT when initiating BiPAP. Abbreviations: IPAP: inspiratory positive Or NIV pathway available on Critical Care Seek and treat reversible causes AHRF: acute hypercapnic airway pressure pH <7.35 and pCO2 >6.5kPa of AHRF respiratory failure OHS: obesity Outreach infonet BiPAP: BiLevel positive hypoventilation syndrome airway pressure NIV: non-invasive (positive- COPD: chronic obstructive pressure) ventilation pulmonary disease NMD: neuromuscular *Possible need for EPAP >8 CWD: chest wall deformity disease Severe OHS (BMI >35), lung recruitment e.g. EPAP: expiratory positive PEEP: positive end hypoxia in severe KS, oppose intrinsic PEEP in airway pressure expiratory pressure severe airflow obstruction or to maintain adequate KS: Kyphoscoliosis PS: pressure support PS when high EPAP required. IMV: invasive mechanical VC: vital capacity ventilation Adapted from BTS guidelines for ventilatory management of patients with AHRF. 2017. BSUH. AHRF group. 2017. JM. DH. KT