Objective To evaluate the efficiency and associated factors of noninvasive positive pressure ventilation( NPPV) in the treatment of acute lung injury( ALI) and acute respiratory distress syndrome( ARDS) .Methods Twenty-eight patients who fulfilled the criteria for ALI/ARDS were enrolled in the study. The patients were randomized to receive either noninvasive positive pressure ventilation( NPPV group) or oxygen therapy through a Venturi mask( control group) . All patients were closely observed and evaluated during observation period in order to determine if the patients meet the preset intubation criteria and the associated risk factors. Results The success rate in avoiding intubation in the NPPV group was 66. 7%( 10/15) , which was significantly lower than that in the control group ( 33. 3% vs. 86. 4% , P = 0. 009) . However, there was no significant difference in the mortality between two groups( 7. 7% vs.27. 3% , P =0. 300) . The incidence rates of pulmonary bacteria infection and multiple organ damage were significantly lower in the NPPV success subgroup as compared with the NPPV failure group( 2 /10 vs. 4/5, P =0. 01;1 /10 vs. 3/5, P = 0. 03) . Correlation analysis showed that failure of NPPV was significantly associated with pulmonary bacterial infection and multiple organ damage( r=0. 58, P lt;0. 05; r =0. 53, P lt;0. 05) . Logistic stepwise regression analysis showed that pulmonary bacterial infection was an independent risk factor associated with failure of NPPV( r2 =0. 33, P =0. 024) . In the success subgroup, respiratory rate significantly decreased( 29 ±4 breaths /min vs. 33 ±5 breaths /min, P lt; 0. 05) and PaO2 /FiO2 significantly increased ( 191 ±63 mmHg vs. 147 ±55 mmHg, P lt;0. 05) at the time of 24 hours after NPPV treatment as compared with baseline. There were no significant change after NPPV treatment in heart rate, APACHEⅡ score, pH and PaCO2 ( all P gt;0. 05) . On the other hand in the failure subgroup, after 24 hours NPPV treatment, respiratory rate significantly increased( 40 ±3 breaths /min vs. 33 ±3 breaths /min, P lt;0. 05) and PaO2 /FiO2 showed a tendency to decline( 98 ±16 mmHg vs. 123 ±34 mmHg, P gt; 0. 05) . Conclusions In selected patients, NPPV is an effective and safe intervention for ALI/ARDS with improvement of pulmonary oxygenation and decrease of intubation rate. The results of current study support the use of NPPV in ALI/ARDS as the firstline choice of early intervention with mechanical ventilation.
Objective To analyze the risk factors of treatment failure by noninvasive positive pressure ventilation (NPPV) in patients with acute respiratory failure (ARF) due to acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and explore the best time that NPPV be replaced by invasive ventilation when NPPV failure occurs. Methods The data of patients with ARF due to AECOPD who were treated with NPPV from January 2013 to December 2015 were retrospectively collected. The patients were divided into two groups: the NPPV success group and the NPPV failure group (individuals who required endotracheal intubation or tracheotomy at any time). The Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ score was analyzed; the Glasgow Coma Scale score, respiratory rate (RR), pH value, partial pressure of oxygen (PaO2), PaO2/fraction of inspired oxygen (FiO2) ratio, and partial pressure of carbon dioxide were also analyzed at admission, after 2 hours of NPPV, and after 24 hours of NPPV. Results A total of 185 patients with ARF due to AECOPD were included. NPPV failed in 35.1% of the patients (65/185). Multivariate analysis identified the following factors to be independently associated with NPPV failure: APACHEⅡscore≥30 [odds ratio (OR)=20.603, 95% confidence interval (CI) (5.309, 80.525), P<0.001], RR at admission≥35 per minute [OR=3.723, 95%CI (1.197, 11.037), P=0.020], pH value after 2 hours of NPPV<7.25 [OR=2.517, 95%CI (0.905, 7.028), P=0.070], PaO2 after 2 hours of NPPV<60 mm Hg (1 mm Hg=0.133 kPa) [OR=3.915, 95%CI (1.374, 11.508), P=0.010], and PaO2/FiO2 after 2 hours of NPPV<200 mm Hg [OR=4.024, 95%CI (1.542, 11.004), P=0.010]. Conclusion When patients with ARF due to AECOPD have a higher severity score, have a rapid RR at admission, or fail to improve in terms of pH and oxygenation after 2 hours of NPPV, the risk of NPPV failure is higher.
Objective To study the effect of noninvasive positive pressure ventilation (NPPV) in chronic obstructive pulmonary disease (COPD) patients with hypercapnic coma secondary to respiratory failure.Methods COPD patients with or without coma secondary to respiratory failure were both treated by bi-level positive airway pressure (BiPAP) ventilation on base of routine therapy.There were 32 cases in coma group and 42 cases in non-coma group.Such parameters as arterial blood gas (ABG)，Glasgow coma scale (GCS)，time of NPPV therapy，achievement ratio，and adverse effects were investigated.Results 30 patients in the coma group were improved after NPPV treatment (26 cases recovered consciousness treated by BiPAP in 2 hours，3 cases recovered between 3~8 hours，1 case recovered after 24 hours).The parameters of ABG，the tidal volume and the minute ventilation volume were improved after BiPAP.The time of effective therapy was (9±4) days in the coma group and (7±3) days in the non-coma group with no significant difference (Pgt;0.05).The achievement ratio was similar in two groups (93.75% vs 97.62%，Pgt;0.05).But the incidence of gastrointestinal tympanites reached to a higher level in the coma group (80.5%) than the non-coma group (10.6%).Conclusion COPD patients with hypercapnic coma secondary to respiratory failure isn’t the absolute contraindication of NPPV treatment.
Objective To determine the efficacy and prognosis of noninvasive positive pressure ventilation (NPPV) in exacerbations of chronic obstructive pulmonary disease (COPD). Methods Trials were located through electronic searches of MEDLINE, EMBASE, Springer, and Foreign Journals Integration System (from the start date to March 2008). We also checked the bibliographies of retrieved articles. Statistical analysis was performed with The Cochrane Collaboration’s software RevMan 4.2.10. Results A total of 19 trials involving 1 236 patients were included. Results showed that: (1) NPPV vs. conventional therapy: NPPV was superior to conventional therapy in terms of intubation rate (RR 0.36, 95%CI 0.27 to 0.49), failure rate (RR 0.62, 95%CI 0.43 to 0.90), and mortality (RR 0.49, 95%CI 0.34 to 0.69). The length of hospital stay was shorter in the NPPV group compared with the conventional group (WMD – 3.83, 95%CI – 5.78 to – 1.89), but the length of ICU stay was similar. The changes of PaO2, PaCO2, and pH were much more obvious in the NPPV group compared with the conventional group. The change of respiratory rate was more significant in the NPPV group compared with the conventional group (WMD – 3.75, 95%CI – 5.48 to – 2.03). At discharge and follow-up, there were no significant differences in FEV1, pH, PaCO2, PaO2, and vital capacity between the two groups. (2) NPPV vs. invasive ventilation: the mortality was similar between the two groups. The incidence of complications was lower in the NPPV group compared with the invasive group (RR 0.38, 95%CI 0.20 to 0.73). The length of ICU stay, duration of mechanical ventilation, and weaning time were shorter in the NPPV group than those of the invasive group. At discharge and follow-up, clinical conditions were similar between the two groups. Conclusion The limited current evidence showed that NPPV was superior to conventional therapy in improving intubation rate, mortality, short term of blood-gas change, the change of respiratory rate; and superior to invasive ventilation in the length of hospital stay and the incidence of complication. There were no difference among them in discharge and follow-up.
ObjectiveTo explore the reason of failure in noninvasive positive pressure ventilation (NPPV) for treatment of postoperative hypoxemia, in order to better guide use of NPPV after cardiac surgery. MethodsWe retrospectively analyzed the clinical data of 64 patients after heart surgery with undergoing NPPV treatment due to hypoxemia in our hospital between January 2012 and December 2013 year.There were 49 males and 15 females at age of 28 to 87 years. There were 17 patients with NPPV failure. The related factors for failure of NPPV were analyzed. ResultsFactors associated with failure of NPPV included smoking history, preoperative pulmonary function abnormalities, blood transfusion amount > 1 000 ml, simplified acute physiology score Ⅱ(SAPS Ⅱ) before NPPV > 35 points, oxygenation index (PaO2/FiO2) < 100 mm Hg before NPPV, PaO2/FiO2 < 150 mm Hg after NPPV treatment for 1 h, mechanical ventilation time > 72 h at the first time, and pneumonia (P < 0.05). The SAPS Ⅱ > 35 points before NPPV and pneumonia were the independent risk factors for NPPV treatment failure for postoperative hypoxemia. ConclusionPostoperative NPPV for heart disease should be according to the cause of low oxygen and severity. For patients with SAPS less than 35 points before NPPV or patients with pneumonia, NPPV should not be used. In the process of NPPV, if clinical effect is not satisfied, it should be converted to invasive ventilation immediately.
Objective To investigate the physiological effects of different oxygen injection site on ventilatory status and oxygenation during noninvasive positive pressure ventilation ( NPPV) with portable noninvasive ventilators. Methods A prospective crossover randomized study was performed. Oxygen injection site was randomized into the outlet of the ventilator, the connection site between mask and circuit, and the mask under the condition of leak port immobilized in the mask. Oxygen flow was retained in the baseline level at the initial 5 to 10 minutes, and adjusted to obtain arterial oxygen saturation measured by pulse oximetry ( SpO2 ) ranging from 90% to 95% after SpO2 remains stable. SpO2 at the initial 5 to 10 minutes, oxygen flow, ventilatory status, oxygenation, hemodynamics and dyspnea indexes at0. 5 hour, 1 hour, and 2 hours of NPPV were compared between different oxygen injection sites. Results 10 patients were recruited into the study. Under the condition of the same oxygen flow, SpO2 with oxygen injection site in the outlet of the ventilator was significantly higher than that with oxygen injection site in the connection site between mask and circuit [ ( 98.9 ±0.9) % vs. ( 96.9 ±1.1) % , P =0. 003] , whereas SpO2 with oxygen injection site in the connection site between mask and circuit was significantly higher than that with oxygen injection site in the mask [ ( 96.9 ±1.1) % vs. ( 94.1 ±1.6) %, P = 0.000] . Oxygen flow with oxygen injection site in the mask was statistically higher than that with oxygen injection site at other sites ( P lt; 0.05) . Arterial oxygen tension/ oxygen flow with oxygen injection site in the outlet of the ventilator was significantly higher than that with oxygen injection site in the connection site between mask and circuit ( 67.9 ±31.1 vs. 37.0 ±15.0, P =0.007) , and than that with oxygen injection site in the mask ( 67.9 ± 31.1 vs. 25.0 ±9.1, P = 0.000) . pH, arterial carbon dioxide tension, hemodynamics and dyspnea indexes were not significantly different between different oxygen injection sites ( P gt; 0.05) .Conclusions When portable noninvasive ventilator was applied during NPPV, oxygen injection site significantly affects improvement of oxygenation, and shows a trend for affecting ventilatory status and work of breathing. When the leak port was immobilized in the mask, the nearer oxygen injection site approaches the outlet of the ventilator, the more easily oxygenation is improved and the lower oxygen flow is demanded.
Objective To investigate the effects of noninvasive positive pressure ventilation (NPPV) on patients with acute left heart failure. Methods Twenty patients with acute left heart failure diagnosed between September 2013 and July 2014 were randomized into treatment group (n=10) and control group (n=10). Both groups used conventional sedations, diuretics and drugs that strengthened the heart and dilated the vessels, while early use of NPPV was applied in the experimental group. Arterial blood gas analysis [pH value, pressure of arterial carbon dioxide (PaCO2), and pressure of arterial oxygen (PaO2)], heart rate (HR), respiration, duration of Intensive Care Unit (ICU) stay and invasive mechanical ventilation, duration of overall mechanical ventilation, and success case numbers before and two hours after treatment were observed and analyzed. Results For the control group, two hours after treatment, PaO2 was (67.0±8.5) mm Hg (1 mm Hg=0.133 kPa), HR was (124±10) times/min, Respiration was (34±4) times/min, the duration of ICU stay was (6.0±1.1) days, invasive ventilation was for (32.0±3.1) hours, and the total time of mechanical ventilation was (32.0±3.1) hours. Those indexes for the treatment group two hours after treatment were: PaO2, (82.3±8.9) mm Hg; HR, (98±11) times/min; respiration, (24±4) times/min; the duration of ICU stay, (4.0±0.8) days; invasive ventilation time, (16.0±1.3) hours; the total time of mechanical ventilation, (26.0±1.8) hours. All the differences for each index between the two groups were statistically significant (P < 0.05). Conclusion Early application of NPPV can rapidly relieve clinical symptoms and reduce the medical cost for patients with acute left heart failure.
Objective To investigate the effectiveness of noninvasive positive pressure ventilation( NPPV) in acute exacerbation of chronic obstructive pulmonary disease ( AECOPD) complicated with severe type Ⅱ respiratory failure.Methods 37 patients who were admitted fromJanuary 2008 to June 2009 due to AECOPD complicated with severe type Ⅱ respiratory failure and had received NPPV therapy were enrolled as a NPPV group. Another similar 42 cases who had not received NPPV therapy served as control. All subjects received standard medication therapy according to the guideline. Arterial blood gases before and after treatment, the duration of hospitalization and intubation rate were observed. Results The arterial pH, PaO2 ,and PaCO2 improved significantly after treatment as compared with baseline in both groups ( P lt; 0. 05) .Compared with the control group, the average duration of hospitalization was significantly shorter ( 10 ±5 vs.19 ±4 days, P lt;0. 05) and the intubation rate was significantly lower ( 2. 7% vs. 16. 7% , P lt;0. 05) in the NPPV group. Conclusion The use of NPPV in AECOPD patients complicated with severe type Ⅱ respiratory failure is effective in improving arterial blood gases, reducing the duration of hospitalization and intubation rate.
ObjectiveTo analyze the effect of noninvasive positive pressure ventilation (NPPV) on the treatment of severe acute pancreatitis (SAP) combined with lung injury [acute lung injury (ALI)/acute respiratory distress syndrome (ARDS)] in emergency treatment. MethodsFifty-six patients with SAP combined with ALI/ARDS treated between January 2013 and March 2015 were included in our study. Twenty-eight patients who underwent NPPV were designated as the treatment group, while the other 28 patients who did not undergo NPPV were regarded as the control group. Then, we observed patients' blood gas indexes before and three days after treatment. The hospital stay and mortality rate of the two groups were also compared. ResultsBefore treatment, there were no significant differences between the two groups in terms of pH value and arterial partial pressure of oxygen (PaO2) (P>0.05). Three days after treatment, blood pH value of the treatment group and the control group was 7.41±0.07 and 7.34±0.04, respectively, with a significant difference (P＜0.05); the PaO2 value was respectively (60.60±5.11) and (48.40±3.57) mm Hg (1 mm Hg=0.133 kPa), also with a significant difference (P＜0.05). The hospital stay of the treatment group and the control group was (18.22±3.07) and (23.47±3.55) days with a significant difference (P＜0.05); and the six-month mortality was 17% and 32% in the two groups without any significant difference (P>0.05). ConclusionIt is effective to treat patients with severe acute pancreatitis combined with acute lung injury in emergency by noninvasive positive pressure ventilation.
Objective To investigate the effects of mask BiPAP noninvasive positive ventilation (NIPPV) during treadmill exercise on dyspnea index and exercise endurance in stable patients with severe chronic obstructive pulmonary disease (COPD). Methods Twenty inpatients with stable severe COPD between August 2015 and January 2016 were recruited in the study. The following parameters were measured before and after 8-week rehabilitation by NIPPV during treadmill exercises, including 12-minute walking distance (12MWD), Borg dyspnea score, mean pulmonary arterial pressure (mPAP), PaO 2 and PaCO 2, times of acute exacerbation in 1 year, adverse reactions, and adherence. Results After rehabilitation for 8 weeks, the following parameters were improved than those before treatment including 12MWD [(810±20) mvs. (680±15) m,P<0.01], Borg dyspnea score (2.4±0.1vs. 4.4±0.3,P<0.01), mPAP [(34.4±2.7) mm Hgvs. (43.5±3.8) mm Hg], PaCO 2 [(49.8±4.9) mm Hgvs. (64.3±5.2) mm Hg], PaO 2 [(64.4±4.1) mm Hgvs. (52.3±3.9) mm Hg] and the times of acute exacerbation (2.1±0.7vs. 4.3±2.1,P<0.01). Adverse reactions included oropharyngeal drying (2 cases) and gaseous distention (8 cases) which can be tolerated without special treatment. Conclusion Mask NIPPV during treadmill exercise is safe and effective for stable patients with severe COPD and worthy of clinical application.