ObjectiveTo assess the mortality, acute exacerbations, exercise capacity, symptoms and significant physiological parameters (lung function, respiratory muscle function and gas exchange) of patients with severe stable chronic obstructive pulmonary disease (COPD) with respiratory failure treated by noninvasive positive pressure ventilation (NPPV).MethodsA meta-analysis of randomized controlled trials was carried out by searching PubMed, Cochrane library, Embase, OVID, Chinese Biomedical Literature Database and the bibliographies of the retrieved articles up to February 2017. Studies of patients with severe stable COPD with respiratory failure receiving long-term noninvasive positive pressure ventilation and comparison with oxygen therapy were conducted, and at least one of the following parameters were reviewed: frequency of acute exacerbations, mortality, lung function, respiratory muscle function, gas exchange, 6-minute walk test.ResultsSix studies with 695 subjects met the inclusion criteria and were analyzed. The PaCO2 was significantly decreased in patients who received long-term NPPV. No significant difference was found between long-term NPPV and oxygen therapy in mortality, frequency of acute exacerbations, gas exchange, lung function, respiratory muscle function and exercise capacity. The subgroup analysis showed that NPPV improves survival of patients when it is targeted at greatly reducing hypercapnia.ConclusionCurrent evidence suggests that there is no significant improvement by application of NPPV on severe stable COPD with respiratory failure patients, but NPPV may reduce patients’ mortality with the aim of reducing hypercapnia.
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.
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.
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 explore the effects of enteral tube feeding on moderate AECOPD patients who underwent noninvasive positive pressure ventilation ( NPPV) . Methods Sixty moderate AECOPD patients with NPPV admitted from January 2009 to April 2011 were recruited for the study. They were randomly divided into an enteral tube feeding group (n=30) received enteral tube feeding therapy, and an oral feeding group (n=30) received oral feeding therapy. Everyday nutrition intake and accumulative total nutrition intake in 7 days, plasma level of prealbumin and transferrin, success rate of weaning, duration of mechanical ventilation, length of ICU stay, rate of trachea cannula, and mortality rate in 28 days were compared between the two groups. Results Compared with the oral feeding group, the everyday nutrition intake and accumulative total nutrition intake in 7 days obviously increased (Plt;0.05) , while the plasma prealbumin [ ( 258.4 ±16.5) mg/L vs. (146.7±21.6) mg/L] and transferrin [ ( 2.8 ±0.6) g/L vs. ( 1.7 ±0.3) g/L] also increased significantly after 7 days in the enteral tube feeding group( Plt;0.05) . The success rate of weaning ( 83.3% vs. 70.0%) , the duration of mechanical ventilation [ 5. 6( 3. 2-8. 6) days vs. 8. 4( 4. 1-12. 3) days] , the length of ICU stay [ 9. 2( 7. 4-11. 8) days vs. 13. 6( 8.3-17. 2) days] , the rate of trachea cannula ( 16. 6% vs. 30. 0% ) , the mortality rate in 28 days ( 3. 3% vs. 10. 0% ) all had significant differences between the enteral tube feeding group and the oral feeding group. Conclusions For moderate AECOPD patients with NPPV, enteral tube feeding can obviously improve the condition of nutrition and increase the success rate of weaning, shorten the mechanical ventilation time and the mean stay in ICU, decrease the rate of trachea cannula and mortality rate in 28 days. Thus enteral tube feeding should be preferred for moderate AECOPD patients with NPPV.
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.
ObjectiveTo investigate the value of noninvasive positive pressure ventilation in patients with high risk of weaning induced pulmonary oedema.MethodsFrom June 2018 to June 2019, 63 patients with mechanical ventilation in the Department of Critical Care Medicine of the First Hospital of Lanzhou University were enrolled. Randomized digital table method was randomly divided into two groups and the resulting random number assignment was hidden in opaque envelopes, the experimental group received non-invasive positive pressure ventilation (n=32), and the control group received mask oxygen therapy ventilation (n=31). The heart rate, respiratory rate, means arterial pressure, hypoxemia, reintubation, blood gas analysis and other indicators were compared between the two groups after 2 hours of weaning. The length of hospital stay, mortality and complications were compared between the two groups.ResultsAfter 2 hours of weaning, the heart rate and respiratory rate were significantly lower in the non-invasive positive pressure ventilation group than in the mask group (P<0.05). There was no difference in mean arterial pressure between the two groups of patients, which was not statistically significant (P>0.05). The incidence of hypoxemia, laryngeal edema and reintubation in the noninvasive positive pressure ventilation group was significantly lower than that in the mask group, which was statistically significant (P<0.05), and the blood gas analysis index was better than the mask group (P<0.05). The non-invasive positive pressure ventilation group was significantly shorter than the mask group in the length of hospital stay and intensive care unit (P<0.05). The hospital mortality rate in 28 days was lower than that in the mask group (P<0.05), but there was no difference in tracheotomy, pneumothorax and subcutaneous emphysema between the two groups (P>0.05).ConclusionsNoninvasive positive pressure ventilation can effectively prevent hypoxemia, laryngeal edema, and re-intubation in patients at high risk of withdrawal related pulmonary edema. It can also shorten the length of hospital stay, which is worth clinical attention and promotion.
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 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.