CPAP is beneficial in situations where ventilatory drive is unimpaired and there is no obstructive process. Ideally, it would be used in pulmonary edema (Eur Hear Journal 23:1379, 2002) and BiPap would be used for asthma and COPD.
If CPAP is used, start with low pressures (5 cmH2O) and increase in increments of 2 cmH2O as tolerated by the patient. Respiratory goals may include an exhaled tidal volume greater than 7 mL/kg, a respiratory rate of less than 25, oxygen saturation greater than 90%, and perhaps most important, patient comfort.
BiPap is a combination of CPAP and Pressure Support Ventilation. It is a leak tolerant system that can be provided by face or nasal mask.
With BiPAP, the IPAP setting may range from 4-24 cmH2O, while the EPAP setting may vary from 2-20 cmH2O. Typical initial settings for BiPAP are levels of 8-10 IPAP and 2-4 EPAP. These settings presume that the lower pressures will allow patient tolerance and training. When using BiPAP, remember that the inspiratory pressure must be maintained higher than the expiratory pressure at all times to ensure bi-level flow. Flow must be synchronized with patient respiratory efforts. Expiratory should not exceed 8 (No additional benefit) Esophageal sphincter opens at 23 (So do not exceed this with IPAP)
best review: Crit Care Med 2005;33(11):2651
Best review of NIV (Chest 2007;132:711)
Am J Respir Crit Care Med. 2006 Jan 15;173(2):164-70. Epub 2005 Oct 13. Related Articles, Links Early noninvasive ventilation averts extubation failure in patients at risk: a randomized trial. Ferrer M, Valencia M, Nicolas JM, Bernadich O, Badia JR, Torres A. Unitat de Cures Intensives i Intermedies, Servei de Pneumologia, Hospital Clinic, Institut Clinic del Torax, Villarroel 170, 08036 Barcelona, Spain. firstname.lastname@example.org RATIONALE: Respiratory failure after extubation and reintubation is associated with increased morbidity and mortality. OBJECTIVES: To assess the efficacy of noninvasive ventilation in averting respiratory failure after extubation in patients at increased risk. METHODS: A prospective randomized controlled trial was conducted in 162 mechanically ventilated patients who tolerated a spontaneous breathing trial after recovery from the acute episode but had increased risk for respiratory failure after extubation. Patients were randomly allocated after extubation to receive noninvasive ventilation for 24 h (n = 79), or conventional management with oxygen therapy (control group, n = 83). MEASUREMENTS AND MAIN RESULTS: The primary end-point variable was the decrease in respiratory failure after extubation. In the noninvasive ventilation group, respiratory failure after extubation was less frequent (13, 16 vs. 27, 33%; p = 0.029) and the intensive care unit mortality was lower (2, 3 versus 12, 14%; p = 0.015). However, 90-d survival did not change significantly between groups. Separate analyses of patients without and with hypercapnia (arterial CO(2) tension greater than 45 mm Hg) during the spontaneous breathing trial showed that noninvasive ventilation improved intensive care unit mortality (0 vs. 4, 18%; p = 0.035) and 90-d survival (p = 0.006) in hypercapnic patients only; of them, 98% had chronic respiratory disorders. CONCLUSIONS: The early use of noninvasive ventilation averted respiratory failure after extubation and decreased intensive care unit mortality among patients at increased risk. The beneficial effect of noninvasive ventilation in improving survival of hypercapnic patients with chronic respiratory disorders warrants a new prospective clinical trial.
A meta-analysis of noninvasive weaning to facilitate liberation from mechanical ventilation [Une méta-analyse dun sevrage non effractif pour faciliter le retrait de la ventilation mécanique] Karen E.A. Burns, MD MSc FRCPC*,, Neill K.J. Adhikari, MD FRCPC, and Maureen O. Meade, MD MSc FRCPC, * From the Division of Critical Care Medicine, London Health Sciences Centre-Victoria Hospital, London; Interdepartmental Division of Critical Care, University of Toronto,Toronto; Department of Critical Care Medicine, Hamilton General Hospital, Hamilton; and the Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. Address correspondence to: Dr. Karen E.A. Burns, McMaster University, 1200 Main Street W., Room 2C10, Hamilton, Ontario L8N 3Z5, Canada. Phone: 905-525-9140, ext. 22804; Fax: 905-331-5895; E-mail: email@example.com Purpose: To summarize the evidence comparing noninvasive positive pressure ventilation (NPPV) and invasive positive pressure ventilation (IPPV) weaning on mortality, ventilator associated pneumonia and the total duration of mechanical ventilation among invasively ventilated adults with respiratory failure. Source: Meta-analysis of randomized and quasi-randomized studies comparing early extubation with immediate application of NPPV to IPPV weaning. We selected randomized studies that 1) included adults, with respiratory failure, invasively ventilated for at least 24 hr; 2) compared extubation with immediate application of NPPV to weaning using IPPV; and 3) reported at least one clinically important outcome. Principal findings: We searched MEDLINE (1966 to 2003), EMBASE (1980 to 2003) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003) for randomized controlled trials comparing NPPV and IPPV weaning. Additional data sources included personal files, conference proceedings and author contact. Two reviewers independently assessed trial quality and abstracted data. Five studies enrolling 171 patients demonstrated that compared to IPPV, noninvasive weaning decreased mortality (relative risk, 0.41 [95% confidence interval [CI] 0.220.76]), ventilator associated pneumonia (relative risk, 0.28 [95% CI 0.090.85]) and the total duration of mechanical ventilation (weighted mean difference, 7.33 days [95% CI 11.45 to 3.22 days]). Conclusions: In the absence of a large randomized controlled trial, this meta-analysis demonstrated a consistent positive effect of noninvasive weaning on mortality. Notwithstanding, the use of NPPV to facilitate weaning, in mechanically ventilated patients, with predominantly chronic obstructive pulmonary disease, is associated with promising, but insufficient, evidence of net clinical benefit at present.
60 A Soroksky, D Stav and I Shpirer, A pilot, prospective, randomized, placebo-controlled trial of bilevel positive airway pressure in acute asthmatic attack, Chest 123 (2003), pp. 10181025. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (75)
61 T Soma, M Hino, K Kida and S Kudoh, A prospective and randomized study for improvement of acute asthma by non-invasive positive pressure ventilation (NPPV), Intern Med 47 (2008), pp. 493501. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (2)
protocol for non-invasive in ALI/ARDS (Crit Care Med 2007;35(1):18)
Nasal is More Effective than Full-Face Mask in Unconscious Patients
Continuous positive airway pressure and ventilation is more effective with anasal mask than a full face mask in unconscious subjects: a randomizedcontrolled trial (Critical Care2013,17:R300)