CPAP is beneficial in situations where ventilatory drive is
unimpaired and there is no obstructive process.
Ideally, it would be used in pulmonary
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.
miferrer@clinic.ub.es
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 d’un 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: burnsk@smh.toronto.on.ca
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] 0.22–0.76]), ventilator associated pneumonia (relative
risk, 0.28 [95% CI 0.09–0.85]) 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.
protocol for non-invasive in ALI/ARDS (Crit Care Med 2007;35(1):18)
