Agenda Definition & mechanism of action Indications When, who, where, what & how ? Technical aspects Weaning off NIV Complications NONINVASIVE VENTILATION Non-invasive ventilation (NIV) refers to a form of assisted ventilation that involves provision of ventilatory support without endotracheal intubation (ETI) CPAP vs. NIV CPAP NIV Pressure greater than atm applied to proximal airway throughout resp cycle Greater pressure applied during inspiration over and above the baseline CPAP Splints airway Unloads resp muscles Increases lung volume Can provide complete resp support Raises intrathoracic pressures Does not offload resp muscles NIV – how it works Decreasing work of breathing Off loading of resp muscles & decreasing fatigue Preventing wide swings in intrathoracic pressure Decreasing afterload to heart Preventing complications of IMV Intubation & MV Loss of airway defenses Post extubation issues NIV Whom to initiate ? Acute COPD Pulmonary edema Immunocompromised patients Weaning from mechanical Neuromuscular weakness Bronchial asthma ARDS Do not intubate – pts Other indications Chronic What is expected of NIV ? NIV in COPD exacerbation COPD exacerbation is a perfect indication for NIV use Excellent candidates for partial respiratory support Offloads respiratory muscles & prevents dynamic hyperinflation Gives time for the bronchodilators & steroids to take effect Supports till balance of respiratory system is restored First study on COPD exacerbation Pressure support ventilation by face mask leads to: Reduced need for intubation Duration of mechanical ventilation Duration of ICU stay LIMITATIONS OF STUDY Used historical controls Not randomized controlled trial Bochard et al., 1990 NEJM First RCT Compared NIV (n =30)with conventional therapy (n = 30):Equal number received bronchodilators, corticosteroids and antibiotics therapy Within first hour NIV patients had greater improvement in pCO2 and dyspnea score Mortality of 10% in NIV group as compare to 30 % in control group Bott et al, Lancet 1993 Risk of treatment failure in seven studies of NPPV as an adjunct to usual medical care 3 0.17 NPPV Usual Medical Care 0.3 2.5 6.60 2 6 0.38 0.58 0.51 1.5 1 0.63 0.5 0.51 (95% CI) Total 2000 Plant et al et al 2002 Dikensoy al 1998 Celikel et et al 1995 Brochard 1993 Bott et al 1996 Barbe et al al 1998 Avdeev et 0 BMJ 2003;;326:1-5 NPPV Usual medical care Avdeev et al 1998 7/29 12/29 0.58 (0.27 to 1.27) Barbe et al 1996 4/14 0/10 6.60 (0.39 to 110.32) Bott et al 1993 5/30 13/30 0.38 (0.16 to 0.94) Brochard et al 1995 12/43 33/42 0.36 (0.21 to 0.59) Celikel et al 1998 1/15 6/15 0.17 (0.02 to 1.22) Dikensoy et al 2002 4/19 7/17 0.51 (0.18 to 1.45) Plant et al 2000 22/118 35/118 0.63 (0.39 to 1.00) Total (95% CI) 55/268 106/261 0.51 (0.38 to 0.67) Study Risk ratio (fixed 95% CI) Risk ratio (fixed 95% CI) BMJ 2003;;326:1-5 Risk of treatment failure in seven studies of NPPV as an adjunct to usual medical care 3 Total (95% CI) 0.20 0.50 Plant et al 2000 1 Kramer et al 1995 0.35 Dikensoy et al 2002 0.62 Celikel et al 1998 4 Brochard et al 1995 5 Bott et al 1993 6 Barbe et al 1996 2 Avdeev et al 1998 Risk of endotracheal intubation in eight trials of NPPV as an adjunct to usual medical care 0.14 NPPV Usual medical Care 0.29 0.42 0.56 0 Study NPPV Usual medical care Avdeev et al 1998 5/29 8/29 0.62 (0.23 to 1.68) Barbe et al 1996 0/10 0/10 Not estimable Bott et al 1993 0/30 2/30 0.20 (0.01 to 4.0) Brochard et al 1995 11/43 31/42 0.35 (0.20 to 0.60) Celikel et al 1998 1/15 2/15 0.50 (0.05 to 4.94) Dikensoy et al 2002 2/17 7/17 0.29 (0.07 to 1.18) Kramer et al 1995 1/11 8/12 0.14 (0.02 to 0.92) Plant et al 2000 18/118 32/118 0.56 (0.34 to 0.94) Total (95% CI) 38/273 90/273 0.42 (0.31 to 0.59) Risk ratio (fixed 95% CI) BMJ 2003;;326:1-5 Risk of endotracheal intubation in eight trials of NPPV as an adjunct to usual medical care Risk ratio (fixed 95% CI) 0.50 Total (95% CI) 0.33 Plant et al 2000 0 Dikensoy et al 2002 0.33 Celikel et al 1998 0.33 Brochard et al 1995 10 9 8 7 6 5 4 3 2 1 0 Bott et al 1993 0.33 Barbe et al 1996 Avdeev et al 1998 Mortality in seven studies of NPPV as an adjunct to usual medical care NPPV Usual medical care 0.50 0.41 Study NPPV Usual medical care Avdeev et al 1998 3/29 9/29 0.33 (0.10 to 1.11) Barbe et al 1996 0/10 0/10 Not estimable Bott et al 1993 3/30 9/30 0.33 (0.10 to 1.11) Brochard et al 1995 4/43 12/42 0.33 (0.11 to 0.93) Celikel et al 1998 0/15 1/15 0.33 (0.01 to 7.58) Dikensoy et al 2002 1/17 2/17 0.50 (0.05 to 5.01) Plant et al 2000 12/118 24/118 0.50 (0.26 to 0.95) Total (95% CI) 23/62 57/261 0.41 (0.26 to 0.64) Risk ratio (fixed 95% CI) Risk ratio (fixed 95% CI) BMJ 2003;;326:1-5 Mortality in seven studies of NPPV as an adjunct to usual medical care Role of NIV in COPD exacerbation Established beyond doubt that NIV decreases Failure Intubation (NNT 4) Mortality (NNT 10) Chandra et al. analyzed healthcare utilization between 1998 -2008 and concluded that patients who get intubated after failed NIV had higher mortality Increasing use of NIV in difficult to ventilate patients Continuation of NIV despite lack of early improvement NIV in cardiogenic pulmonary edema Robust data supporting use of NIV in CPE Cochrane review of 21 trials and 1071 subjects showed NIV Decreases intubation (NNT 8) Decreases in hospital mortality (NNT 13) Does not increase risk of MI Winck et al, reviewed 7 studies comparing NIV vs. CPAP and showed both were equally efficient even in patients with hypercapnea NIV in extubation NIV as a tool for facilitating extubation and weaning off ventilator NIV post extubation for preventing respiratory failure for patients at risk NIV as a treatment for established extubation failure NIV in weaning Latest review included 16 trials involving 994 patients with COPD & mixed populations They analysed effect on Weaning failure VAP Mortality Effect on weaning failure Effect on VAP Effect on mortality NIV for preventing weaning failure in at risk group Patients of hypercapneic respiratory failure including COPD, neuromuscular dis orders NIV post extubation as per protocol to prevent weaning failure Studies have shown significant benefit with NIV in these sub- groups NIV in established extubation failure 2 trials till date have looked at NIV in established extubation failure Both have not shown any benefit in Re intubation rate ICU mortality NIV in post operative patients Main aim in post operative patients is Prevent acute respiratory failure Treat acute respiratory failure and prevent intubation 29 studies identified in a recent review Significant heterogeneity in the type of surgery, patient co morbidities & outcome measurements Take home point is despite lack of RCT NIV improved blood gas & prevents hypoxemia in most cases Summarizing role in weaning Definite role in weaning COPD patients Preventing re-intubation in high risk group No evidence to support its use in established weaning failure Should be considered in post operative period for preventing & treating respiratory failure Immunocompromised patients NIV plays a vital role in management of these patients Intubation is associated with significant morbidity & mortality 2 RCTs & several observational studies have been consistent in demonstrating NIV Improves oxygenation Reduces intubation Reduces mortality NIV in ARDS Area of intense debate & no consensus Studies & systematic reviews have shown May decrease intubation rates, ICU stay in select sub-groups who show early response High rates of failure Disturbingly patients who get intubated after failed NIV have higher mortality Use with caution / not at all When in doubt, intubate NIV in asthma Data is scarce in Asthma Early studies showed no clear benefit Recent study from PGI showed better lung function with lower bronchodilator requirements with NIV Likely to remain this way as with modern therapy established respiratory failure requiring ventilatory support is very rare NIV in do not intubate NIV is being increasingly used in these patients especially in wards Recent studies have shown Up to 43 % of these patients survive to discharge Depends on primary etiology COPD & CCF fare better Better sensorium / ability to clear secretions have better outcome Post exubation failure, hypoxemic respiratory failure & end stage cancers patients fare poorly NIV in DNI- guidelines Goals NIV in patients without any restrictions to other life supporting treatments NIV in patients refusing endotracheal intubation NIV as the only support (TLC group) Need to discuss goals clearly & get consent from relatives Unclear issues Whether actually provides comfort ? Or Just prolongs the dying process ? NIV in chest trauma Recent systematic review of 9 studies showed in In blunt trauma chest without ALI, NIV Reduces intubation Hypoxemia ICU stay Mortality With established ALI Controversial with no good data NIV for pre-oxygenation 2 RCTs have evaluated 3-5 mins of NIV as compared to routine preoxygenation before intubation NIV associated with Higher SpO2 immediately after & at 5 mins Higher lung volumes Especially in morbidly obese patients NIV in OHS Acute exacerbation patients fare similarly if not better than COPD patients with hypercapneic respiratory failure They they get intubated, will need NIV immediately post extubation These patients need continuance of care with home NIV Can have late NIV failures because of non compliance NIV facilitated FOB Patient receives NIV (10/5) by full face mask @ 100% FiO2 for 5 minutes preceding procedure Patient’s vitals & SpO2 are continuously monitored NIV facilitated FOB Bronchoscope is introduced through“dual axis swivel” adapter of a catheter mount This is done after patient is adequately oxygenated NIV facilitated FOB 2 % lidocaine gel for lubrication & local anesthesia Mask is replaced after nasal entry of bronchoscope Tight apposition to ensure no leak Vitals are continuously monitored NIV facilitated FOB BAL - wedging scope against approprite segment (3-5 alliquots of ~ 50 ml NS) TBLB – after decreasing CPAP to 0 & PS = 10 cms NIV continued for 30 mins post procedure Mechanism of action of NIV • Splinting of upper airway & increasing cross sectional area • Counteracting the PEEPi created due to obstruction caused by bronchoscope • Ability to provide FiO2 of 1 • Recruitment of collapsed alveoli- thereby reducing shunt fraction & increasing FRC • Decreases WOB Evidence… Author (Year) Study No. of patients Age ± SD Gender NIV setting M:F NIV duration Bronchoscopi Complications c procedure CPAP-4 PSV-17 FiO2-1 10 minutes before FOB and 90 minutes after the procedure BAL Two patients died after 5 & 7 days of FOB due to underlying disease CPAP titrated in incremental steps of 2.5 cm H2O up to 7.5 cm 5 minutes before FOB and 30 minutes after the procedure BAL Bronchial biopsy Eight patients required intubation, 7 in the O2 group and 1 in CPAP group BAL 4 in NIV 7 in O2 died of underlying illness No procedural complications Antonel Prospective 8 li et observational al(3) (1996) 40 ± 14 years Maitre et al (2002) 30 With CPAP15 Without CPAP-15 58 (3578) 57 (2683) 26 13-NIV 13-O2 supplement by venturi mask NIV 8:8 in 52 ± 20 both years groups O2 - 57 ± 10 years CPAP-4 PSV-15 to 17 FiO2-0.9 10 minutes before FOB and 30 minutes after the procedure Antonel Prospective 4 li et al observational (2003) 60.25 years PSV-10 to 20 PEEP- 8 to 14 FiO2-0.7to 0.9 Before and during BAL FOB and 30 minute after procedure One patient died after 48 hours due to underlying disease Heunks Prospective 12 et al observational (2010) 64.25 years PSV-10 PEEP- 6 FiO2-1 20 minutes before FOB until SpO2 > 92% @ FiO2 0.4 BAL Worsening hypoxemia during procedure in 1 patient requiring temporary withdrawal of FOB Scala et Prospective al case-control (2010) study NIV-80 12:3 ±5 9:6 CMV80 ± 5 PSV-10 to 25 PEEP- 5 FiO2-1 Before FOB until clinical improvement with gradual reduction of PSV BAL None related to the procedure Randomized controlled study Antonel Randomized li et al controlled (2002) study NIV-15 CMV-15 15:4 15:5 6:6 Respir Care. 2012 Mar 13. [Epub ahead of print] Bronchoscopic Lung Biopsy Using Noninvasive Ventilatory Support: Case Series and Review of Literature of NIV-assisted Bronchoscopy. Agarwal R, Khan A, Aggarwal AN, Gupta D. Abstract RESULTS: Six patients with a mean (SD) age of 44.5 (11.6) years were included in the study. The median (IQR) PaO₂/FiO₂ ratio prior to lung biopsy was 164.5 (146.3-176.3) and the median (IQR) IPAP/EPAP used was 14 (12-15)/5 cm H₂O. FOB was well tolerated and all patients maintained SpO₂ >92% during the procedure. One patient required endotracheal intubation due to hemoptysis. A definite diagnosis was obtained in five of the six patients. A repeat procedure was performed in one patient, which again yielded no diagnosis. No other periprocedural complications were encountered. CONCLUSIONS: NIV-assisted BLB is a novel method for obtaining diagnosis in hypoxemic patients with diffuse lung infiltrates. However, this approach should be reserved for centers with extensive experience in NIV. More studies are required to define the utility of this approach. Monitoring during NIV Subjective and objective parameters First 2hrs - intense monitoring Next 8hrs - close monitoring… There after - routine monitoring Even if parameters were borderline at start of NIV, early change / improvement predicts success of NIV This is the most important aspect of NIV First few hours predict the outcome of the patient Monitoring during NIV … Look at patient, ventilator, interface, bed side monitor, ABG … Patient - Comfort, conscious level Chest expansion Accessory muscles Synchrony … Interfaces … Trigger, - leak, tightness volume delivered, cycling … HR, RR, SpO2, BP … ABG - pCO2, pH, pO2 at base line, 1-2hrs after, then based on response Trouble shooting Potential issues Solutions 1. Leak 1. Check mask fit/ strap position/ tubings / ? Chin strap 2. Agitation / asynchrony 2. Talk to patient / adjust settings / sedation /analgesia 3. Hypoxia 3. Adjust ventilator / FiO2/ intubate 4. Adjust ventilator / FiO2/ intubate 4. Hypercarbia Potential indicators of success in NIV Younger age … Lower acuity of illness … Able to cooperate … Better neurologic score … Less air leak … … PaCO2 45 - 60 mmHg … pH 7.10 - 7.35 Synchronous breathing … Intact dentition … Less secretions … Better compliance … Improvements in gas exchange and heart respiratory rates within first 2 hours … Situations where NIV is likely to fail Hypercapnic failure Hypoxemic failure GCS < 11 Diagnosis of ARDS / pneumonia RR > 35/min Age > 40 PH < 7.25 SBP < 90 APACHE > 29 Metabolic acidosis PH < 7.25 Asynchrony Low PO2/ FiO2 Agitation / intolerance Simplified APS II > 34 Failure of PO2 / FiO2 to improve above 175 by 1st hour Edentulous / excessive leak No initial improvement Weaning patients from NIV No specific protocol Pts of COPD would require at least 24 hours to stabilise NIV is usually removed as per patient’s request for feeding/facial hygiene Re – attached as deemed necessary Attempt gradual decrease in IPAP / EPAP & discontinue when patient tolerates Complications of NIV Failure is the most serious complication Most dreaded complication is failure to recognize NIV failure early leading to delay in intubation Studies have shown that this can lead to increased mortality especially when used in situations where NIV is used without strong evidence Complications of NIV Principles of mechanical ventilation. 3e Summary & conclusions NIV is an important tool in the hands of RT & intensivist Provides a level of respiratory support in emergency / wards unimaginable otherwise Has changed the way we manage COPD exacerbations Needs careful monitoring during initial hours A tool which needs to be used wisely for us to reap the benefits