non invasive ventilation in acute care hospital

A.AZIMI MD Anesthesiologist , Intensivist Bushehr university of medical science

corona virus disease 2019 (COVID-19) represents the greatest medical crisis the world has confronted since the “Great Influenza” pandemic of 1918.

P/F ratio : Pao2/FIo2

ROX index [o2 saturation /Fio2 ]/respiratory rate >4.88 predict success HFNC

Adults:SpO2 ≥ 90% in non-pregnant patientsSpO2 ≥ 92–95% in pregnant patients

Indications for NIV Exclusions for NIV Benefits of an Acute NIV Service Complications Protocols for Acute NIV Monitoring Practical application

Noninvasive ventilation (NIV)

delivery of positive-pressure ventilatory support to the upper airway without the need for an invasive artificial airway

It has been increasingly used over the past 15 years to treat both acute and chronic forms of respiratory failure

Improved gas exchange Work of breath Dyspnea need for intubation (ETI) mortality & morbidity Incidence of Hospital infections (sepsis & HAP) Duration of invasive monitoring Duration of hospital stay Need for mechanical ventilation (MV)

• Correction of gas exchange, Dyspnea , Work of breath ,Improve lung mechanics

• Reduce resistive work imposed by invasive ventilation• Ventilates effectively with lower pressures

• Intermittent application• Patient comfort• Correct mental status

Preserves speech/swallowing/expectoration Reduces need for nasogastric tubes. Reduce need for sedation Avoids complications of ETT Trauma/injury, aspiration Avoids complications of invasive ventilation

• Infection-pneumonia, sepsis, sinusitis• GI bleed• DVT• Less cost

Hypercapnic respiratory failure

COPD exacerbation A

Asthma C

Hypoxemic respiratory failure

Cardiogenic pulmonary edema A

Pneumonia C

ALI/ARDS C

Immunocompromised A

Post op respiratory failure B

Extubation failure C

Do not intubate status C

Preintubation oxygenation B

Facilitation of bronchoscopy B

Critical care med ,2007 :35 ;10 :2403

Leaks Mask discomfort facial soreness, facial skin breakdown Eye irritation Sinus congestion Oronasal drying Gastric insufflation Hemodynamic compromise

Unstable hemodynamics (hypotension, uncontrolled arrhythmias or myocardial ischemia).

Inability to protect the respiratory tract . Excessive bronchial secretion. Signs of impaired consciousness the patient's inability to cooperate with medical

personnel. Facial trauma, burns, anatomical disorders that

prevent masking.

Select appropriate patient Choose a ventilator capable of meeting

patient needs (usually pressure ventilation) Choose the correct interface; avoid mask that

is too large Explain therapy to the patient choose low settings Initiate NPPV while holding mask in place

NPPV

SUCCESS

clinician

skills

Interface

and

Ventilator

Patient

Selection

1) Make sure about the oxygen outlet delivery of at least 90%

2) Nasal Cannula up to 6 L/min

3) Face Mask 7-10 L/min

4) NRBFM or Reservoir mask (good fit) 10-15 L/min5) 5) High Flow Nasal Cannula (HFNC) titer to target SpO2

6) Non-invasive Ventilation (NIV) with high flow oxygen (10-20 L/min)a) Tight fit mask , helmet if availableb) CPAP : 10 to 16 cmH2Oc) BIPAP : I/E = 10-24 cmH2O/4-10 cmH2O (results in PS of 6 to 14)d) It depends on patient’s tolerancee) Staff availability to control delivery of NIV

Pressure Modes Better tolerated than volume cycled mode Constant positive airway pressure(CPAP) Pressure support ventilation (PSV) Bilevel or biphasic positive airway pressure (BiPAP)

Volume Modes Initial TV range 8-15 ml/kg

• Control• Assist control

CPAP for hypoxaemic repiratory failure :5-15 cmH2O + 60-100% oxygen.

PS for hypercapnic respiratory failureinitial settings are PS 8-10 cmH20 + PEEP 5-10

cmH2O + 60-100% oxygen, targeting SpO2 of 88 –92%

consist of inspiratory positive airway pressure (IPAP) expiratory positive airway pressure (EPAP)

The difference between IPAP and EPAP is a reflection of the amount of pressure support ventilation

EPAP is synonymous with positive end-expiratory pressure (PEEP)

Wherever non-invasive ventilatory support is used, a clear plan must be in place to determine the threshold for failure and escalation to intubation and invasive mechanical ventilation if appropriate.

• Once CPAP/NIV has been begun, clinical progress should initially be reviewed hourly (or more frequently, where clinically indicated) to determine whether there is improvement or deterioration.

Monitoring should focus on the regular measurement of

respiratory rate, work of breathing, oxygen saturation heart rate.

Lack of improvement within 1-2 hrs of initiation of therapy

Patient intolerance of therapy Adverse effects: hypotension

• The patient's inability to carry the mask due to discomfort or pain.

• The inability of the NIV to improve gas exchange within 2 hours: an increase or preservation of hypoxemia, despite the high values of PEEP and FiO2.

• Inability to mask ventilation to ease dyspnea.

The need for endotracheal intubation to remove secretions or protect the respiratory tract

Instability of hemodynamics and ECG, instability with the phenomena of ischemia or clinically significant ventricular arrhythmias.

The increase in encephalopathy.

there should be a low threshold for intubationwhere there is clinical decline (which may include a rising oxygen requirement, consistently or rapidly declining SpO2, consistently or rapidly increasing respiratory rate and increased work of breathing).

A trial of weaning CPAP/NIV to conventional oxygen therapy can be considered when oxygen concentration < 40%

Thank You