NIMV

Dr. Güngör Ateş16/04/2011

• No conflict of interest

CASE 1

• 66 yo M with known COPD presents with 5 days of worsening dyspnea. RR=30, BP:80/40, pulse oximetry 83%. Alert.

• chest discomfort and difficulty in breathing since the last hour ↑ ↑

• ECG: evidence of AMI• Chest X-ray. Lucency ↑ ↑• lack of significant response to treatment • ABG : pH=7.26, pO2=55, CO2=56, Bicarb=34

Treatment does not really help—what should you do?

• A. Addition of a diuretic• B. Intubation and ventilation• C. NIMV• D.All of the above

• BTS GUIDELINE Non-invasive ventilation in acute respiratory failure British Thoracic Society Standards of Care Committee. Thorax 2002;57:192–211

• Chawla R, Khilnani GC, Suri JC, et al. Guidelines for noninvasive ventilation in acute respiratory failure. Indian J Crit Care Med 2006;10:117-47

• Royal College of Physicians, British Thoracic Society, Intensive Care Society Chronic obstructive pulmonary disease: non-invasive ventilation with bi-phasic positive airways pressure in the management of patients with acute type 2 respiratory failure. Concise Guidance to Good Practice series, No 11. London RCP, 2008.

• Bernd Schönhofer. Clinical Practice Guideline: Non-Invasive Mechanical Ventilation as Treatment of Acute Respiratory Failure. Dtsch Arztebl Int 2008; 105(24): 424–33.

• Sean P. Keenan MD MSc. Clinical practice guidelines for the use of noninvasive positive-pressure ventilation and noninvasive continuous positive airway pressure in the acute care setting. CMAJ, February 22, 2011, 183(3)

Acute Respiratory Failure/ NIMV

• Clinical Criteria– Moderate to severe respiratory distress– Tachypnea (>24/min)– Accessory muscle use or abdominal paradox

• Gas Exchange Criteria– PaCO2>45 mmHg, pH <7.35; >7.10– pO2 <60 mm on high flow O2

• Exclusion Criteria (Contraindications)

NIMV

• Clinical Criteria• Gas Exchange Criteria• Exclusion Criteria (Contraindications)

– Respiratory arrest or immediate need for intubation– Medically unstable

• Acute MI, uncontrolled arrhythmias, cardiac ischemia, upper GI bleeding, hypotensive shock

– Unable to protect airway• Impaired swallowing or cough• Excessive secretion

– Agitated or uncooperative– Recent upper airway or esophageal surgery– Unable to fit mask

CASE 2:• 66 year old male• Smoker /COPD• presents with 3 days of worsening

dyspnea and sputum• Pulse 112, RR 33, BP 100/50,

alert, afebrile.• Chest: distant wheezes, no

infiltration• Increase work of breathing• Treatment initiated with oxygen,

nebs, steroids,ab• ABG: pH 7.28, pCO2 58 and pO2

70 on 2l nasal• lack of significant response to

treatment

What should be the furthercourse of action?

• A. Continue treatment with continuous nebulization

• B. Consider intubation and ventilation

• C. NIMV• D. Addition of a diuretic

• NIV should be considered for all COPD patients with a persisting respiratory acidosis after a maximum of one hour of standard medical therapy [A]

• Patients with a pH <7.26 may benefit from NIV but such patients have a higher risk of treatment failure and should be managed in a high dependency or ICU setting [A]

NIV in Acute Respiratory Failure:NIV in Acute Respiratory Failure:

Kramer et al, Am J Respir Crit Care Med 1995; 151: 1799-806

00 11 22 33 66 1212 2424 4848 7272

00

4040

8080

Control 12 (8) 67%

NPPV 11 (1) 9%**

Time in Hours

% COPD Patients % COPD Patients Needing Needing

IntubationIntubation

* p < 0.05

Respiratory Failure due to Acute Exacerbation of COPD

• First line intervention as an adjunct to usual medical care. NPPV should be considered early in the course of respiratory failure.

• Decrease in mortality of 48% – RR=0.52, (95%CI .35-.76)

• Decrease of intubation by 59% – RR=.41, (95%CI .33-.53)

• Decrease hospital length of stay 3.24 days– 95%CI -4.42 to -2.06

Ram FSF, Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews 2004.Brochard L et al. N Eng J Med 323:1523, 1990Krammer N et al. Am J Respir Crit Care Med 15:1799, 1995

ABG taken 1 and 2 hours after NIMV, / no improvement

What is your next step strategy?

• A. Cont. NIMV• B. Medical treatment• C. IMV• D. Add nebul. steroids

Nasal Masks• Advantages

– Less risk of aspiration– Easier secretion clearance– Less claustrophobia– Easier speech– Less dead space

• Disadvantages– Mouth leak– Higher resistance through nasal passages– Less effective with nasal obstruction– Nasal irritation and rhinorrhea– Mouth dryness

Some are More Complicated than Others

Full Face Masks• Advantages

– Better ventilation for dyspneic patients• Disadvantages

– Increased dead space– Increased risk of facial pressure sores– Claustrophobia– Increased aspiration risk– Cannot speak or eat– Asphyxiation with ventilator malfunction– Difficult to fit

Initiating NIMV

• Appropriate patient selection and TIME!• Semi-recumbent position• Select mask / comfort (full face mask)• Set IPAP at 8-10 cm/EPAP at 4-5 cm• Titrate IPAP slowly to maintain tidal volume 6

cc/kg snd reduce RR, and EPAP for hypoxemia• Monitor oxygen sats, heart rate and resp. rate

Monitoring• ABG: at 1,4 and 12 hours• RR and HR:at 1 hour• Level of consciousness,Chest wall

movement, Use of accessory muscles• SpO2 and cardiac monitoring, first 12

hours• Patient comfort/compliance are key

factors• Synchrony of ventilation• Assessment of mask fit/skin condition /

degree of leak

Complications of NIMV

Mask-related Frequency (%)

Discomfort 30-50Facial skin erythema 20-34Claustrophobia 5-10Nasal bridge ulceration 5-10Acneiform rash 5-10

Management of Mask-Related Problems

– Check fit– Adjust strap– Apply water based jelly to mask contact

points– Try new mask type– Apply artificial skin– Adj. pressure

Management of Mask-Related Problems

• Claustrophobia– Small mask/nasale mask– Sedation

• Nasal bridge ulceration– Loosen strap tension– Apply artificial skin– New mask

• Acneiform rash– Topical steroids or antibiotics

Management of Air Pressure- 0r Flow-Related Problems

• Nasal congestion– Nasal steroids– Decongesestants/antihistamine

• Sinus/oral dryness– Nasal saline– Add humidifier– Reduce air leak

• Sinus/ear pain– Reduce pressure if intolerable

Management of Air Pressure- 0r Flow-Related Problems

• Eye irritation–Check mask fit–Readjust straps

• Gastric insufflation–NG–Simethacone–Reduce pressure if intolerable

Complications of NIMV

Frequency (%)

Air leaks 80-100Major complications Aspiration pneumonia < 5 Hypotention < 5 Pneumothorax < 5

Management of Air Leaks

• Encourage mouth closure• Oro-nasal mask if using nasal

mask• Apply water-based jelly to mask

contact points• Reduce pressure slightly• Readjust straps

Management of Major Complications

• Aspiration pneumonia– Select patients carefully

• Hypotension– Reduce inflation pressure

• Pneumothorax– Stop ventilation if possible– Reduce airway pressure– Insert a thoracostomy tube if indicated

Humidification during NIMV

No humidification: drying of nasal mucosa; increased airway resistance; decreased compliance.

HME lessens the efficacy of NIMV Only pass-over humidifiers should

be used

Intensive Care Med. 2002;28

MESSAGE

• Compliance with NIV, patient-ventilator synchrony and mask comfort are key factors in determining outcome and should be checked regularly [C]

• Staff/ appropriately trained and experienced [B]