Noninvasive Pressure Support Ventilation Research Articles

Comparative Physiologic Effects of Noninvasive Assist-Control and Pressure Support Ventilation in Acute Hypercapnic Respiratory Failure

To compare the effects of noninvasive assist-control ventilation (ACV) and pressure support ventilation (PSV) by nasal mask on respiratory physiologic parameters and comfort in acute hypercapnic respiratory failure (AHRF). A prospective randomized study. A medical ICU. Fifteen patients with COPD and AHRF were consecutively and randomly assigned to two noninvasive ventilation (NIV) sequences with ACV and PSV mode, spontaneous breathing (SB) via nasal mask being used as control. ACV and PSV settings were always subsequently adjusted according to patient's tolerance and air leaks. Fraction of inspired oxygen did not change between the sequences. ACV and PSV mode strongly decreased the inspiratory effort in comparison with SB. The total inspiratory work of breathing (WOBinsp) expressed as WOBinsp/tidal volume (VT) and WOBinsp/respiratory rate (RR), the pressure time product (PTP), and esophageal pressure variations (deltaPes) were the most discriminant parameters (p<0.001). ACV most reduced WOBinsp/VT (p<0.05), deltaPes (p<0.05), and PTP (0.01) compared with PSV mode. The surface diaphragmatic electromyogram activity was also decreased >32% as compared with control values (p<0.01), with no difference between the two modes. Simultaneously, NIV significantly improved breathing pattern (p<0.01) with no difference between ACV and PSV for VT, RR, minute ventilation, and total cycle duration. As compared to SB, respiratory acidosis was similarly improved by both modes. The respiratory comfort assessed by visual analog scale was less with ACV (57.23+/-30.12 mm) than with SB (75.15+/-18.25 mm) (p<0.05) and PSV mode (81.62+/-25.2 mm) (p<0.01) in our patients. During NIV for AHRF using settings adapted to patient's clinical tolerance and mask air leaks, both ACV and PSV mode provide respiratory muscle rest and similarly improve breathing pattern and gas exchange. However, these physiologic effects are achieved with a lower inspiratory workload but at the expense of a higher respiratory discomfort with ACV than with PSV mode.

Non-invasive pressure support ventilation (NIPSV) is not very time-consuming for the nursing staff

Non-invasive pressure support ventilation (NIPSV) is not very time-consuming for the nursing staff

Weaning from mechanical ventilation in COPD patients: interest to measure, in post-extubation, the airway occlusion pressure (P0.1), in order to indicate non-invasive pressure support ventilation (NIPSV) to prevent relapse

Weaning from mechanical ventilation in COPD patients: interest to measure, in post-extubation, the airway occlusion pressure (P0.1), in order to indicate non-invasive pressure support ventilation (NIPSV) to prevent relapse

Noninvasive nasal pressure support ventilation in emergency patients with exacerbations of tuberculosis sequelae

Noninvasive nasal pressure support ventilation in emergency patients with exacerbations of tuberculosis sequelae

Noninvasive Ventilation for Acute Exacerbations of Chronic Obstructive Pulmonary Disease

In patients with acute exacerbations of chronic obstructive pulmonary disease, noninvasive ventilation may be used in an attempt to avoid endotracheal intubation and complications associated with mechanical ventilation. We conducted a prospective, randomized study comparing noninvasive pressure-support ventilation delivered through a face mask with standard treatment in patients admitted to five intensive care units over a 15-month period. A total of 85 patients were recruited from a larger group of 275 patients with chronic obstructive pulmonary disease admitted to the intensive care units in the same period. A total of 42 were randomly assigned to standard therapy and 43 to noninvasive ventilation. The two groups had similar clinical characteristics on admission to the hospital. The use of noninvasive ventilation significantly reduced the need for endotracheal intubation (which was dictated by objective criteria): 11 of 43 patients (26 percent) in the noninvasive-ventilation group were intubated, as compared with 31 of 42 (74 percent) in the standard-treatment group (P < 0.001). In addition, the frequency of complications was significantly lower in the noninvasive-ventilation group (16 percent vs. 48 percent, P = 0.001), and the mean (+/- SD) hospital stay was significantly shorter for patients receiving noninvasive ventilation (23 +/- 17 days vs. 35 +/- 33 days, P = 0.005). The in-hospital mortality rate was also significantly reduced with noninvasive ventilation (4 of 43 patients, or 9 percent, in the noninvasive-ventilation group died in the hospital, as compared with 12 of 42, or 29 percent, in the standard-treatment group; P = 0.02). In selected patients with acute exacerbations of chronic obstructive pulmonary disease, noninvasive ventilation can reduce the need for endotracheal intubation, the length of the hospital stay, and the in-hospital mortality rate.

Bi-level positive airway pressure support system use in acute congestive heart failure: preliminary case series.

To describe the use of a noninvasive bi-level positive airway pressure (PAP) support system for ED patients with acute congestive heart failure (CHF). Retrospective case series analysis of ED patients presenting with acute CHF in imminent need of endotracheal intubation (ETI) managed with a bi-level PAP system. The bi-level PAP system was applied at the discretion of the treating emergency physician. Management of the bi-level PAP system, including setting of inspiratory PAP (IPAP) and expiratory PAP (EPAP), weaning, adjunct pharmacologic therapy, and failure of bi-level PAP support, was determined by the treating physician. Only two (9%) of 22 patient presentations necessitated ETI. The mean duration of bi-level PAP therapy was 7.9 hours. The mean maximum IPAP and EPAP settings were 10.8 and 5.8 cm H2O, respectively. Mean intensive care unit length of stay (LOS) was 2.4 days, with a median LOS of only 1 day. There were three deaths in the series; none were attributed to the bi-level PAP system. No technical difficulty with the bi-level PAP system was noted. Noninvasive pressure support ventilation with a bi-level PAP support system may avert ETI in acute CHF patients. This device can be effectively used by ED personnel.

Pulmonary barotrauma following non-invasive pressure support ventilation

Pulmonary barotrauma following non-invasive pressure support ventilation

Pulmonary barotrauma following non-invasive pressure support ventilation

A Servo 900 C Siemens ventilator was used to provide nasal pressure support ventilation for a patient with acute respiratory failure. Shortly after commencing ventilation the patient developed a pneumothorax and surgical emphysema of the face, neck and upper chest. Breath ‘stacking’, resulting in hyperinflation and subsequent barotrauma secondary to inefficient triggering and cycling from inspiration to expiration of the Servo 900 C ventilator, is suggested as the mechanism responsible.

Noninvasive Pressure Support Ventilation in Patients With Acute Respiratory Failure: A Randomized Comparison With Conventional Therapy

The benefit of noninvasive pressure support ventilation (NIPSV) in avoiding the need for endotracheal intubation and reducing morbidity and mortality associated with endotracheal intubation was evaluated in 41 patients who presented with acute respiratory failure not related to chronic obstructive pulmonary disease (COPD). Patients were randomly assigned to receive conventional therapy (n = 20) or conventional therapy plus NIPSV (n = 21). NIPSV was delivered to the patient by a face mask connected to a ventilator (Puritan-Bennett 7200a) set in inspiratory pressure support (IPS) mode. The mean levels of IPS, positive end-expiratory pressure (PEEP), and fraction of inspired oxygen (FIO2) were respectively 15 +/- 3 cm H2O, 4 +/- 2 cm H2O, and 57 +/- 22%. The rate of endotracheal intubation (62 vs 70%, p = 0.88), the length of ICU stay (17 +/- 19 days vs 25 +/- 23 days, p = 0.16), and the mortality rate (33 vs 50%, p = 0.46) were not different between patients treated with NIPSV and those treated conventionally. Post hoc analysis suggested that in patients with PaCO2 > 45 mm Hg (n = 17), NIPSV was associated with a reduction in the rate of endotracheal intubation (36 vs 100%, p = 0.02), in the length of ICU stay (13 +/- 15 days vs 32 +/- 30 days, p = 0.04), and in the mortality rate (9 vs 66%, p = 0.06). We conclude that NIPSV is of no benefit when used systematically in all forms of acute respiratory failure not related to COPD. A subgroup of patients, characterized by acute ventilatory failure and hypercapnia, may potentially benefit from this therapy and further studies are needed to focus on this aspect.

Physiologic effects of positive end-expiratory pressure and mask pressure support during exacerbations of chronic obstructive pulmonary disease.

To assess physiologic effects of continuous positive airway pressure (CPAP) and positive end-expiratory pressure (PEEP) during noninvasive pressure support ventilation (PSV) in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD), we measured in seven patients the breathing pattern, lung mechanics, diaphragmatic effort (PTPdi), and arterial blood gases under four conditions: (1) spontaneous breathing (SB); (2) CPAP; (3) PSV of 10 cm H2O; and (4) PSV plus PEEP (PEEP + PSV). CPAP and PEEP were set between 80 and 90% of dynamic intrinsic PEEP (PEEPidyn) measured during SB and PSV, respectively. PEEPidyn was obtained (1) from the decrease in pleural pressure (delta Ppl) preceding inspiration, and (2) subtracting the fall in gastric pressure (delta Pga) caused by relaxation of the abdominal muscles from the delta Ppl decrease. Abdominal muscle activity made PEEPidyn overestimated in almost all instances (p < 0.0001). PSV increased minute ventilation, improved gas exchange, and decreased PTPdi. PEEP added to PSV, likewise CPAP compared with SB, further significantly decreased the diaphragmatic effort (PTPdi went from 322 +/- 111 to 203 +/- 63 cm H2O.s) by counterbalancing PEEPidyn, which went from 5.4 +/- 4.0 to 3.1 +/- 2.3 cm H2O. These data support the use of low levels of PEEP (80 to 90% of PEEPidyn) to treat acute exacerbation of COPD by means of mask PSV.

Noninvasive Pressure Support Ventilation in Patients With Acute Respiratory Failure

To further delineate indications for noninvasive pressure support ventilation (NIPSV), we proposed this noninvasive technique as an alternative to endotracheal intubation in 17 consecutive patients with acute respiratory failure from various causes. Eight patients (47 percent) were successfully ventilated with NIPSV, while in 9 (53 percent), NIPSV failed. Gas exchange values before initiating NIPSV were different between the 2 groups: patients successfully ventilated with NIPSV had a higher PaCO2 (57 +/- 15 mm Hg vs 37 +/- 17 mm Hg; p = 0.01), a lower pH (7.33 +/- 0.03 vs 7.45 +/- 0.08; p = 0.02), and a lower alveolo-arterial oxygen pressure difference (P[A-a]O2) (144 +/- 46 mm Hg vs 265 +/- 18 mm Hg; p = 0.01), suggesting that CO2 retention without major hypoxemia is a better indication for NIPSV than severe hypoxemia alone. Acute respiratory failure occurring after extubation seemed to be a good indication for NIPSV, with an 83 percent rate of success. In both groups of patients, gas exchange improved after 1 h on NIPSV, but such values were not improved on the first day in patients who failed with NIPSV.