Non Invasive Ventilation

Invasive ventilationNon invasive ventilation

Positive-pressure ventilationNegative-pressure ventilation

1864 Jones

1876 Woillez

Negative Pressure VentilationFull body ventilator (tank or iron lung)Raincoat ventilator (pneumowrap or pneumosuit)Cuirass ventilator (chest shell)

Corrado A.Iron lung versus mask ventilation in acute exacerbation of COPD: a randomised crossover study.Intensive Care Med2009;35:648-55. Randomised multicentre study. A total of 141 patients were assigned: 70 to ILV and 71 to NPPV. On admission, PaO2/FiO2, 198 (70) and 187 (64), PaCO2, 90.5 (14.1) and 88.7 (13.5) mmHg, and pH 7.25 (0.04) and 7.25 (0.05), were similar for ILV and NPPV groups. When used as first line, the success of ILV (87%) was significantly greater (P=0.01) than NPPV (68%), due to the number of patients that met minor criteria for EI; after the shift of the techniques; however, the need of EI and hospital mortality was similar in both groups. The total rate of success using both techniques increased from 77.3 to 87.9% (P=0.028). Conclusion:The sequential use of NPPV and ILV avoided EI in a large percentage of COPD patients with ARF; ILV was more effective than NPPV.

Non Invasive PositivePressure Ventilation(NIPPV) (NPPV)

Case PresentationChen XX, 59 y/o, male, Dx:COPDPFT in 90-6:0.39(16%)/0.90(29%)/43%1.870405(27)CM2.880129(3)RT3.880222(5)RT4.880324(9)CM@5.881129(61)RT@6.890328(4)CS7.890608(20)RT@8.891129(8)RT#9.891209(42)RT@10.900325(24)CM@11.900516(37)RT@12.900705(11)RT13.900905(50)RT#14.901106(86)RT@15.910313(72)RT@16.910625(38)RT#17.910817(41)RT#18.911016(63)RT@19.920107~920402(85)RT# @:IMV #:NIPPV

19 Admission, Total 696 Days(Mean 36 27 days)No MV: 5 (1,2,3,6,12) IMV : 9 (4,5,7,9,10,11,14,15,18) NIPPV: 5 (8,13,16,17,19) PaO2 / PaCO2 / pH15:910313@0314 69 138 7.133 16:910625# 166 107 7.147 17:910817# 113 124 7.137 18:911016@1125 75 114 7.305 19:920107# 55 107 7.285 (0106) 96 141 7.110 (0107) 131 52 7.439 (0108)8704~9204

Case PresentationFu XX, 17 y/o, maleDx:Otopalatodigital syndromePaO2 / PaCO2 / pH1000217 27 57 7.212 1000218 116 76 7.17 1000218 65 58 7.24 (BiPAP) 1000219 106 51 7.35

BiPAP

85.6.14

Vision

99 13314 2886 286 10.59.9

Absolute contraindicationsComa Cardiac arrest Respiratory arrest Any condition requiring immediate intubation

Relative contraindicationsCardiac instability Shock and need for pressor support Ventricular dysrhythmias Complicated acute myocardial infarctionGI bleeding - Intractable emesis/uncontrollable bleeding Inability to protect airway Impaired cough or swallowing Poor clearance of secretions Depressed sensorium and lethargyStatus epilepticus Potential for upper airway obstruction Extensive head and neck tumors Any other tumor with extrinsic airway compressionAngioedema or anaphylaxis causing airway compromise

Patientinclusion criteriaPatient cooperation (excludes agitated, belligerent, or comatose patients) Dyspnea (moderate to severe, but short of respiratory failure) Tachypnea (>24 breaths/min) Increased work of breathing (accessory muscle use, pursed-lips breathing) Hypercapnic respiratory acidosis (pH range 7.20-7.35) Hypoxemia (PaO2/FIO2

Suitable clinical conditions for non invasive ventilation(most patients)Chronic obstructive pulmonary disease Cardiogenic pulmonary edema

Suitable clinical conditions for non invasive ventilation (selected patients)After discontinuation of mechanical ventilationCommunity-acquired pneumoniaAsthma Immunocompromised state Postoperative respiratory distress Do-not-intubate status Neuromuscular respiratory failure Decompensated obstructive sleep apnea/ cor pulmonale Cystic fibrosis Acute respiratory distress syndrome Mild Pneumocystic carinii pneumonia

Location of applicationICU (especially if possibility of intubation) Step-down unit (lower severity of illness) Moderately severe COPD (pH >7.30) Do-not-intubate status Intermittent or nocturnal ventilatory supportWard setting (not recommended if intubation is indicated) Suitable in specialized units Same considerations as step-down unit Emergency department - Local considerations, expertisemay mirror ICU or step-down unit

Patient interfacesNasal maskFace maskTotal face mask

Nasal mask

Face mask

Total face mask

Nasal masks (general advantages)Best suited for more cooperative patients Better in patients with a lower severity of illness Not claustrophobic Allows speaking, drinking, coughing, and secretion clearance Less aspiration risk with emesis Generally better tolerated

Nasal masks (cautions,disadvantages)More leaks possible (eg, mouth-breathing or edentulous patients) Effectiveness limited in patients with nasal deformities or blocked nasal passages

Orofacial masks (general advantages)Best suited for less cooperative patients Better in patients with a higher severity of illness Better for patients with mouth-breathing or pursed-lips breathing Better in edentulous patients Generally more effective ventilation

Orofacial masks(cautions, disadvantages)Claustrophobic Hinder speaking and coughing Risk of aspiration with emesis

Modes of BiPAPSpontaneous (S) IPAP (inspiratory positive airway pressure) EPAP (expiratory positive airway pressure) Timed (T) BPM (breaths per minute) % IPAP TimeS/TCPAP (continuous positive airway pressure)

Initial IPAP/EPAP settingsStart at 10 cm H2O/5 cm H2O Pressures less than 8 cm H2O/4 cm H2O not advised as thismay be inadequate Initial adjustments to achieve tidal volume of 5-7 mL/kg

Subsequent adjustments based on arterial blood gas values Increase IPAP by 2 cm H2O if persistent hypercapnia Increase IPAP and EPAP by 2 cm H2O if persistent hypoxemia Maximal IPAP limited to 20-25 cm H2O (avoids gastric distension, improves patient comfort) Maximal EPAP limited to 10-15 cm H2O FIO2 at 1.0 and adjust to lowest level with an acceptable pulse oximetry value Back up respiratory rate 12-16 breaths/minute

Predictors of success Response to trial of NIV (1-2h) Decrease in PaCO2 greater than 8 mm Hg Improvement in pH greater than 0.06 Correction ofrespiratory acidosis

Predictors of failureSeverity of illness Acidosis (pH 80 and pH

Intubation guidelinesAny 1 of the following: pH less than 7.20 pH 7.207.25 on 2 occasions 1 hour apart Hypercapnic coma (Glasgow Coma Scale score 60 mm Hg) PaO2 less than 45 mm Hg Cardiopulmonary arrestTwo or more of the following in the context of respiratory distress: Respiratory rate > 35 breaths/minute or < 6 breaths/minute Tidal volume less than 5 mL/kg Blood pressure changes, with systolic less than 90 mm Hg Oxygen desaturation to less than 90% despite adequate supplemental oxygen Hypercapnia (PaCO2 >10 mm increase) or acidosis (pH decline >0.08) from baseline Obtundation Diaphoresis Abdominal paradox

Complications of noninvasive ventilationFacial and nasal pressure injury andsores Result of tight mask seals used to attain adequate inspiratory volumes Minimize pressure by intermittent application of noninvasive ventilation Schedulebreaks (30-90 min) to minimize effects of mask pressure Covervulnerable areas (erythematous points of contact) with protective dressingsGastric distension Avoid by limiting peak inspiratory pressures to less than 25 cm H2O Nasogastric tubes can be placed but can worsen leaks from the mask Nasogastric tube also bypasses the lower esophageal sphincter and permits reflux

Complications of noninvasive ventilationDry mucous membranes andthicksecretions Seen in patients with extended use of noninvasive ventilation Provide humidificationfor noninvasive ventilation devices Provide daily oral careAspiration of gastric contents Especially if emesis during noninvasive ventilation Avoid noninvasive ventilation in patient with ongoing emesis or hematemesis

Complications avoided by noninvasive ventilationVentilator-associated pneumonia Sinusitis Reduction in need for sedative agents

Cost-analysis of noninvasive ventilationDemonstrated to be cost-effective in patient management Even greater cost savings if patients managed in a ward settingAvoids costs of endotracheal intubation and mechanical ventilation Shorter ICU and hospital stays Eliminates costs associated with infectious complications Episodes of ventilator-associated pneumonia reduced by half or more

Noninvasive Ventilation in COPDCOPD is the most suitable condition for noninvasive ventilation. Noninvasive ventilation is most effective in patients with moderate-to-severe disease Hypercapnic respiratory acidosis may define the best responders (pH 7.20-7.30). Noninvasive ventilation is also effective in patients with a pH of 7.35-7.30, but no added benefit is appreciated if the pH is greater than 7.35. The lowest threshold of effectiveness is unknown, but success has been achieved with pH values as low as 7.10.Obtunded COPD patients can be treated, but the success rate is lower. Improvementafter a 1- to 2-hour trial may predict success.

Lightowler JV.Non-invasive positive pressure ventilation to treat respiratory failure resulting from exacerbations of COPD: Cochrane systematic review and meta-analysis.BMJ 2003;326:185.The eight studies included in the review showed that, compared with usual care alone, NPPV as an adjunct to usual care was associated with a lower mortality (relative risk 0.41), a lower need for intubation (relative risk 0.42), lower likelihood of treatment failure (relative risk 0.51), and greater improvements at 1 hour in pH (weighted mean difference 0.03), PaCO2 (weighted mean difference 0.40 kPa), and respiratory rate (weighted mean difference 3.08 breaths per minute). NPPV resulted in fewer complications associated with treatment (relative risk 0.32) and shorter duration of stay in hospital (weighted mean difference 3.24 days). Conclusion: NPPV should be the first line intervention in addition to usual medical care to manage respiratory failure secondary to an acute exacerbation of chronic obstructive pulmonary disease in all suitable patients.

Noninvasive Ventilation After ExtubationNoninvasive ventilation is effective as a bridge support after early extubation. Noninvasive ventilation is an adjunct to weaning (substitutes noninvasive support for invasive support). Patients with underlying COPD are most likely to benefit from noninvasive ventilation after early extubation. Noninvasive ventilation is not as effective in patients with postextubation respiratory distress. COPD patients are a subgroup who may benefit in that situation.

Burns KE.Use of non-invasive ventilation to wean critically ill adults off invasive ventilation: meta-analysis and systematic review.BMJ2009;338:b1574.We identified 12 trials enrolling 530 participants, mostly with chronic obstructive pulmonary disease. Compared with invasive weaning, non-invasive weaning was significantly associated with reduced mortality (relative risk 0.55, 95% confidence interval 0.38 to 0.79), ventilator associated pneumonia (0.29, 95% 0.19 to 0.45), length of stay in intensive care unit (weighted mean difference 6.27 days, 8.77 to 3.78) and hospital (7.19 days, 10.80 to 3.58), total duration of ventilation, and duration of invasive ventilation. Non-invasive weaning had no effect on weaning failures or weaning time. Conclusion: Current trials in critically ill adults show a consistent positive effect of non-invasive weaning on mortality and ventilator associated pneumonia.

Postoperative patientsPostoperative hypoxemia related to atelectasis or pulmonary edema Occurrence following multiple types of surgery (eg, lung, cardiac, abdominal) Randomized trials with postoperative continuous positive airway pressure (CPAP) demonstrate benefit Applied as prophylactic support or with development of hypoxemia Benefit noted with level CPAP levels in 7.5-10 cm H2O range Lower intubation rates, days in ICU, and pneumonia

Zarbock A.Prophylactic nasal continuous positive airway pressure following cardiac surgery protects from postoperative pulmonary complications: a prospective, randomized, controlled trial in 500 patients.Chest2009;135:1252-9.Following extubation, patients were allocated to standard treatment (control) including 10 min of intermittent nCPAP at 10 cm H2O every 4 h or prophylactic nCPAP (study) at an airway pressure of 10 cm H2O for at least 6 h. Results: Prophylactic nCPAP significantly improved arterial oxygenation. Pulmonary complications including hypoxemia, pneumonia, and reintubation rate were reduced in study patients compared to controls (12/232 patients vs 25/ 236 patients, p=0.03). The readmission rate to the ICU was significantly lower in nCPAP-treated patients (7/232 patients vs 14/236 patients, p=0.03). Conclusion: The administration of prophylactic nCPAP following cardiac surgery improved arterial oxygenation, reduced incidence of pulmonary complications including pneumonia and reintubation rate, and reduced readmission rate to the ICU.

Ferreyra GP.Continuous positive airway pressure for treatment of respiratory complications after abdominal surgery: a systematic review and meta-analysis.Ann Surg2008;247:617-26.We evaluated the potential benefit of continuous positive airway pressure (CPAP) to prevent postoperative pulmonary complications (PPCs), atelectasis, pneumonia, and intubation in patients undergoing major abdominal surgery. RESULTS: The meta-analysis was carried out over 9 randomized controlled trials. Overall, CPAP significantly reduced the risk of (1) PPCs (risk ratio, 0.66; 95% confidence interval [CI], 0.52-0.85) with a corresponding NNTB of 14.2 (95% CI, 9.9-32.4); (2) atelectasis (RR, 0.75; 95% CI, 0.58-0.97; NNTB, 7.3; 95% CI, 4.4-64.5); (3) pneumonia (RR, 0.33; 95% CI, 0.14-0.75; NNTB, 18.3; 95% CI, 14.4-48.8).Conclusion: This systematic review suggests that CPAP decreases the risk of PPCs, atelectasis, and pneumonia and supports its clinical use in patients undergoing abdominal surgery.

Acute respiratory distress syndromeNot recommended as first-line therapy in management Limited experience, but may benefit those who do not require immediate intubation Noninvasive ventilation provided via mask or helmet; able to avoid intubation in approximately half Ventilator settings in successful noninvasive ventilation Pressure support ventilation of 14 cm H2O; PEEP of 7 cm H2O Successfully treated patients found to have lower severity of illness (Simplified Acute Physiology Score II 175 after 1 h)

Antonelli M.A multiple-center survey on the use in clinical practice of noninvasive ventilation as a first-line intervention for acute respiratory distress syndrome.Crit Care Med2007;35:18-25.Prospective, multiple-center cohort study. Between March 2002 and April 2004, 479 patients with ARDS were admitted to the intensive care units. 332 ARDS patients were already intubated, so 147 were eligible for the study. Results: NPPV improved gas exchange and avoided intubation in 79 patients (54%). Avoidance of intubation was associated with less ventilator-associated pneumonia (2% vs. 20%; p < .001) and a lower intensive care unit mortality rate (6% vs. 53%; p < .001). Intubation was more likely in patients who were older (p = .02), had a higher SAPS II (p < .001), or needed a higher level of PEEP (p = .03) and pressure support ventilation (p = .02). Only SAPS II >34 and a Pao2/Fio2 < or =175 after 1 hr of NPPV were independently associated with NPPV failure and need for endotracheal intubation.Conclusion: In expert centers, NPPV applied as first-line intervention in ARDS avoided intubation in 54% of treated patients.

Journal of Respiratory Therapy 2009;8(2):13-25

82 7612 NPPV62(75.6%)15 (18.3%)5 (6.1%)

()NPPV

(PH>7.35PH7.35PH7.3PH

PS: *,P

PS: *,P

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