human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Severe acute exacerbation of chronic obstructive pulmonary disease ( AE- COPD ) is a common reason for emergency room ( ER ) visit about which little has been documented from India . Methods Prospect i ve study of the clinical presentation and predictors of outcome in 116 patients presenting with severe AE- COPD requiring admission to the medical intensive care unit between January 2000 and December 2004 . Results Their mean age was 62.1 ± 9.8 years . There were 102 males . Mean duration of COPD was 7.2 ± 5.8 years . All males were smokers ( 22.3 ± 11.2 pack years ) ; 35.2 % smoked cigarettes and 64.8 % smoked bidis . All women were exposed to domestic fuel . Associated co-morbid illnesses were present in 81 patients ( 69.8 % ) ; 53(45.7 % ) had one co-morbid illness and the remaining 28 ( 54.3 % ) had two or more co-morbid illnesses . Evidence of past pulmonary tuberculosis ( PTB ) was present in 28.4 % patients ; 5 patients who also had type II diabetes mellitus had active PTB . Arterial blood gas analysis revealed respiratory failure in 40 ( 33.8 % ) patients ( type I 17.5 % and type II 82.5 % ) .  Invasive mechanical ventilation  was required in 18 patients . Sixteen ( 13.7 % ) patients died . Stepwise multivariate logistic regression analysis revealed need for invasive ventilation ( OR 45.809 , 95%CI 607.46 to 3.009;p < 0.001 ) ; presence of co-morbid illness ( OR 0.126 , 95%CI 0.428 to 0.037;p < 0.01 ) and hypercapnia ( OR 0.114 , 95%CI 1.324 to 0.010;p < 0.05 ) were predictors of death . Conclusion Co-morbid conditions and metabolic abnormalities render the diagnosis of AE- COPD difficult and also contribute to mortality . High prevalence of past PTB and active PTB in patients with AE- COPD suggests an intriguing relationship between smoking , PTB and COPD which merits further study BACKGROUND In developing countries , mortality in children with very severe pneumonia is high , even with the provision of appropriate antibiotics , st and ard oxygen therapy , and other supportive care . We assessed whether oxygen therapy delivered by bubble continuous positive airway pressure ( CPAP ) improved outcomes compared with st and ard low-flow and high-flow oxygen therapies . METHODS This open , r and omised , controlled trial took place in Dhaka Hospital of the International Centre for Diarrhoeal Disease Research , Bangladesh . We r and omly assigned children younger than 5 years with severe pneumonia and hypoxaemia to receive oxygen therapy by either bubble CPAP ( 5 L/min starting at a CPAP level of 5 cm H2O ) , st and ard low-flow nasal cannula ( 2 L/min ) , or high-flow nasal cannula ( 2 L/kg per min up to the maximum of 12 L/min ) . R and omisation was done with use of the permuted block methods ( block size of 15 patients ) and Fisher and Yates tables of r and om permutations . The primary outcome was treatment failure ( ie , clinical failure , intubation and mechanical ventilation , death , or termination of hospital stay against medical advice ) after more than 1 h of treatment . Primary and safety analyses were by intention to treat . We did two interim analyses and stopped the trial after the second interim analysis on Aug 3 , 2013 , as directed by the data safety and monitoring board . This trial is registered at Clinical Trials.gov , number NCT01396759 . FINDINGS Between Aug 4 , 2011 , and July 17 , 2013 , 225 eligible children were recruited . We r and omly allocated 79 ( 35 % ) children to receive oxygen therapy by bubble CPAP , 67 ( 30 % ) to low-flow oxygen therapy , and 79 ( 35 % ) to high-flow oxygen therapy .  Treatment failed for 31 ( 14 % ) children , of whom five ( 6 % ) had received bubble CPAP , 16 ( 24 % ) had received low-flow oxygen therapy , and ten ( 13 % ) had received high-flow oxygen therapy . Significantly fewer children in the bubble CPAP group had treatment failure than in the low-flow oxygen therapy group ( relative risk [ RR ] 0·27 , 99·7 % CI 0·07 - 0·99 ; p=0·0026 ) . No difference in treatment failure was noted between patients in the bubble CPAP and those in the high-flow oxygen therapy group ( RR 0·50 , 99·7 % 0·11 - 2·29 ; p=0·175 ) . 23 ( 10 % ) children died . Three ( 4 % ) children died in the bubble CPAP group , ten ( 15 % ) children died in the low-flow oxygen therapy group , and ten ( 13 % ) children died in the high-flow oxygen therapy group . Children who received oxygen by bubble CPAP had significantly lower rates of death than the children who received oxygen by low-flow oxygen therapy ( RR 0·25 , 95 % CI 0·07 - 0·89 ; p=0·022 ) . INTERPRETATION Oxygen therapy delivered by bubble CPAP improved outcomes in Bangladeshi children with very severe pneumonia and hypoxaemia compared with st and ard low-flow oxygen therapy . Use of bubble CPAP oxygen therapy could have a large effect in hospitals in developing countries where the only respiratory support for severe childhood pneumonia and hypoxaemia is low-flow oxygen therapy . The trial was stopped early because of higher mortality in the low-flow oxygen group than in the bubble CPAP group , and we acknowledge that the early cessation of the trial reduces the certainty of the findings . Further research is needed to test the feasibility of scaling up bubble CPAP in district hospitals and to improve bubble CPAP delivery technology . FUNDING International Centre for Diarrhoeal Disease Research , Bangladesh , and Centre for International Child Health , University of Melbourne CONTEXT Continuous positive airway pressure ( CPAP ) is widely used in the belief that it may reduce the need for intubation and mechanical ventilation in patients with acute hypoxemic respiratory insufficiency . OBJECTIVE To compare the physiologic effects and the clinical efficacy of CPAP vs st and ard oxygen therapy in patients with acute hypoxemic , nonhypercapnic respiratory insufficiency . DESIGN , SETTING , AND PATIENTS R and omized , concealed , and unblinded trial of 123 consecutive adult patients who were admitted to 6 intensive care units between September 1997 and January 1999 with a PaO(2)/FIO(2 ) ratio of 300 mm Hg or less due to bilateral pulmonary edema ( n = 102 with acute lung injury and n = 21 with cardiac disease ) . INTERVENTIONS Patients were r and omly assigned to receive oxygen therapy alone ( n = 61 ) or oxygen therapy plus CPAP ( n = 62 ) . MAIN OUTCOME MEASURES Improvement in PaO(2)/FIO(2 ) ratio , rate of endotracheal intubation at any time during the study , adverse events , length of hospital stay , mortality , and duration of ventilatory assistance , compared between the CPAP and st and ard treatment groups . RESULTS Among the CPAP vs st and ard therapy groups , respectively , causes of respiratory failure ( pneumonia , 54 % and 55 % ) , presence of cardiac disease ( 33 % and 35 % ) , severity at admission , and hypoxemia ( median [ 5th-95th percentile ] PaO(2)/FIO(2 ) ratio , 140 [ 59 - 288 ] mm Hg vs 148 [ 62 - 283 ] mm Hg ; P = .43 ) were similarly distributed . After 1 hour of treatment , subjective responses to treatment ( P<.001 ) and median ( 5th-95th percentile ) PaO(2)/FIO(2 ) ratios were greater with CPAP ( 203 [ 45 - 431 ] mm Hg vs 151 [ 73 - 482 ] mm Hg ; P = .02 ) . No further difference in respiratory indices was observed between the groups . Treatment with CPAP failed to reduce the endotracheal intubation rate ( 21 [ 34 % ] vs 24 [ 39 % ] in the st and ard therapy group ; P = .53 ) , hospital mortality ( 19 [ 31 % ] vs 18 [ 30 % ] ; P = .89 ) , or median ( 5th-95th percentile ) intensive care unit length of stay ( 6.5 [ 1 - 57 ] days vs 6.0 [ 1 - 36 ] days ; P = .43 ) . A higher number of adverse events occurred with CPAP treatment ( 18 vs 6 ; P = .01 ) . CONCLUSION In this study , despite early physiologic improvement , CPAP neither reduced the need for intubation nor improved outcomes in patients with acute hypoxemic , nonhypercapnic respiratory insufficiency primarily due to acute lung injury . JAMA . 2000;284:2352 - 2360 Objective : To assess the role of non-invasive positive pressure ventilation ( NIPPV ) for management of Indian patients with acute exacerbation of chronic obstructive pulmonary disease ( AE COPD ) . Material s and Methods : Forty patients ( mean age 57.6 ± 10.8 years ; M : F 31:9 ) with AE COPD with pH < 7.35 , admitted to the intensive care unit were included . Patients were r and omized to receive  NIPPV  ( N , n = 20 ) with conventional therapy or conventional therapy  ( C , n = 20 ) alone at admission .  NIPPV was given through the nasal mask . Incidence of need of endotracheal intubation ( ETI ) was the primary efficacy variable . Hospital mortality , duration of hospital stay and change in clinical and blood gas parameters were the secondary outcome variables . Results : Mean pH at baseline for N and C groups were similar ( 7.23 ± 0.07 ) whereas PaCO2 was 85.4 ± 14.8 and 81.1 ± 11.6 mm of Hg , respectively . At one hour , patients in N group had greater improvement in pH ( P = 0.017 ) as well as PaCO2 ( P = 0.04 ) which corroborated with clinical improvement . Whereas need of ETI was reduced in patients who received NIPPV ( 3/20 vs 12/20 , P = 0.003 ) , in-hospital mortality was similar ( 3/20 and 2/20 , P = NS ) . The mean duration of hospital stay was significantly shorter in N group ( 9.4 ± 4.3 days ) as compared to C group ( 17.8 ± 2.6 days ) ; P = 0.001 . Conclusions : In patients with AE COPD  , NIPPV leads to rapid improvement in blood gas parameters and reduces the need for BACKGROUND Whether noninvasive ventilation should be administered in patients with acute hypoxemic respiratory failure is debated . Therapy with high-flow oxygen through a nasal cannula may offer an alternative in patients with hypoxemia . METHODS We performed a multicenter , open-label trial in which we r and omly assigned patients without hypercapnia who had acute hypoxemic respiratory failure and a ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen of 300 mm Hg or less to high-flow oxygen therapy , st and ard oxygen therapy delivered through a face mask , or noninvasive positive-pressure ventilation . The primary outcome was the proportion of patients intubated at day 28 ; secondary outcomes included all-cause mortality in the intensive care unit and at 90 days and the number of ventilator-free days at day 28 . RESULTS A total of 310 patients were included in the analyses .  The intubation rate ( primary outcome ) was 38 % ( 40 of 106 patients ) in the high-flow-oxygen group , 47 % ( 44 of 94 ) in the st and ard group , and 50 % ( 55 of 110 ) in the noninvasive-ventilation group ( P=0.18 for all comparisons ) . The number of ventilator-free days at day 28 was significantly higher in the high-flow-oxygen group ( 24±8 days , vs. 22±10 in the st and ard-oxygen group and 19±12 in the noninvasive-ventilation group ; P=0.02 for all comparisons ) . The hazard ratio for death at 90 days was 2.01 ( 95 % confidence interval [ CI ] , 1.01 to 3.99 ) with st and ard oxygen versus high-flow oxygen ( P=0.046 ) and 2.50 ( 95 % CI , 1.31 to 4.78 ) with nonin 
    Output:
    
agent
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Severe acute exacerbation of chronic obstructive pulmonary disease ( AE- COPD ) is a common reason for emergency room ( ER ) visit about which little has been documented from India . Methods Prospect i ve study of the clinical presentation and predictors of outcome in 116 patients presenting with severe AE- COPD requiring admission to the medical intensive care unit between January 2000 and December 2004 . Results Their mean age was 62.1 ± 9.8 years . There were 102 males . Mean duration of COPD was 7.2 ± 5.8 years . All males were smokers ( 22.3 ± 11.2 pack years ) ; 35.2 % smoked cigarettes and 64.8 % smoked bidis . All women were exposed to domestic fuel . Associated co-morbid illnesses were present in 81 patients ( 69.8 % ) ; 53(45.7 % ) had one co-morbid illness and the remaining 28 ( 54.3 % ) had two or more co-morbid illnesses . Evidence of past pulmonary tuberculosis ( PTB ) was present in 28.4 % patients ; 5 patients who also had type II diabetes mellitus had active PTB . Arterial blood gas analysis revealed respiratory failure in 40 ( 33.8 % ) patients ( type I 17.5 % and type II 82.5 % ) .  Invasive mechanical ventilation  was required in 18 patients . Sixteen ( 13.7 % ) patients died . Stepwise multivariate logistic regression analysis revealed need for invasive ventilation ( OR 45.809 , 95%CI 607.46 to 3.009;p < 0.001 ) ; presence of co-morbid illness ( OR 0.126 , 95%CI 0.428 to 0.037;p < 0.01 ) and hypercapnia ( OR 0.114 , 95%CI 1.324 to 0.010;p < 0.05 ) were predictors of death . Conclusion Co-morbid conditions and metabolic abnormalities render the diagnosis of AE- COPD difficult and also contribute to mortality . High prevalence of past PTB and active PTB in patients with AE- COPD suggests an intriguing relationship between smoking , PTB and COPD which merits further study BACKGROUND In developing countries , mortality in children with very severe pneumonia is high , even with the provision of appropriate antibiotics , st and ard oxygen therapy , and other supportive care . We assessed whether oxygen therapy delivered by bubble continuous positive airway pressure ( CPAP ) improved outcomes compared with st and ard low-flow and high-flow oxygen therapies . METHODS This open , r and omised , controlled trial took place in Dhaka Hospital of the International Centre for Diarrhoeal Disease Research , Bangladesh . We r and omly assigned children younger than 5 years with severe pneumonia and hypoxaemia to receive oxygen therapy by either bubble CPAP ( 5 L/min starting at a CPAP level of 5 cm H2O ) , st and ard low-flow nasal cannula ( 2 L/min ) , or high-flow nasal cannula ( 2 L/kg per min up to the maximum of 12 L/min ) . R and omisation was done with use of the permuted block methods ( block size of 15 patients ) and Fisher and Yates tables of r and om permutations . The primary outcome was treatment failure ( ie , clinical failure , intubation and mechanical ventilation , death , or termination of hospital stay against medical advice ) after more than 1 h of treatment . Primary and safety analyses were by intention to treat . We did two interim analyses and stopped the trial after the second interim analysis on Aug 3 , 2013 , as directed by the data safety and monitoring board . This trial is registered at Clinical Trials.gov , number NCT01396759 . FINDINGS Between Aug 4 , 2011 , and July 17 , 2013 , 225 eligible children were recruited . We r and omly allocated 79 ( 35 % ) children to receive oxygen therapy by bubble CPAP , 67 ( 30 % ) to low-flow oxygen therapy , and 79 ( 35 % ) to high-flow oxygen therapy .  Treatment failed for 31 ( 14 % ) children , of whom five ( 6 % ) had received bubble CPAP , 16 ( 24 % ) had received low-flow oxygen therapy , and ten ( 13 % ) had received high-flow oxygen therapy . Significantly fewer children in the bubble CPAP group had treatment failure than in the low-flow oxygen therapy group ( relative risk [ RR ] 0·27 , 99·7 % CI 0·07 - 0·99 ; p=0·0026 ) . No difference in treatment failure was noted between patients in the bubble CPAP and those in the high-flow oxygen therapy group ( RR 0·50 , 99·7 % 0·11 - 2·29 ; p=0·175 ) . 23 ( 10 % ) children died . Three ( 4 % ) children died in the bubble CPAP group , ten ( 15 % ) children died in the low-flow oxygen therapy group , and ten ( 13 % ) children died in the high-flow oxygen therapy group . Children who received oxygen by bubble CPAP had significantly lower rates of death than the children who received oxygen by low-flow oxygen therapy ( RR 0·25 , 95 % CI 0·07 - 0·89 ; p=0·022 ) . INTERPRETATION Oxygen therapy delivered by bubble CPAP improved outcomes in Bangladeshi children with very severe pneumonia and hypoxaemia compared with st and ard low-flow oxygen therapy . Use of bubble CPAP oxygen therapy could have a large effect in hospitals in developing countries where the only respiratory support for severe childhood pneumonia and hypoxaemia is low-flow oxygen therapy . The trial was stopped early because of higher mortality in the low-flow oxygen group than in the bubble CPAP group , and we acknowledge that the early cessation of the trial reduces the certainty of the findings . Further research is needed to test the feasibility of scaling up bubble CPAP in district hospitals and to improve bubble CPAP delivery technology . FUNDING International Centre for Diarrhoeal Disease Research , Bangladesh , and Centre for International Child Health , University of Melbourne CONTEXT Continuous positive airway pressure ( CPAP ) is widely used in the belief that it may reduce the need for intubation and mechanical ventilation in patients with acute hypoxemic respiratory insufficiency . OBJECTIVE To compare the physiologic effects and the clinical efficacy of CPAP vs st and ard oxygen therapy in patients with acute hypoxemic , nonhypercapnic respiratory insufficiency . DESIGN , SETTING , AND PATIENTS R and omized , concealed , and unblinded trial of 123 consecutive adult patients who were admitted to 6 intensive care units between September 1997 and January 1999 with a PaO(2)/FIO(2 ) ratio of 300 mm Hg or less due to bilateral pulmonary edema ( n = 102 with acute lung injury and n = 21 with cardiac disease ) . INTERVENTIONS Patients were r and omly assigned to receive oxygen therapy alone ( n = 61 ) or oxygen therapy plus CPAP ( n = 62 ) . MAIN OUTCOME MEASURES Improvement in PaO(2)/FIO(2 ) ratio , rate of endotracheal intubation at any time during the study , adverse events , length of hospital stay , mortality , and duration of ventilatory assistance , compared between the CPAP and st and ard treatment groups . RESULTS Among the CPAP vs st and ard therapy groups , respectively , causes of respiratory failure ( pneumonia , 54 % and 55 % ) , presence of cardiac disease ( 33 % and 35 % ) , severity at admission , and hypoxemia ( median [ 5th-95th percentile ] PaO(2)/FIO(2 ) ratio , 140 [ 59 - 288 ] mm Hg vs 148 [ 62 - 283 ] mm Hg ; P = .43 ) were similarly distributed . After 1 hour of treatment , subjective responses to treatment ( P<.001 ) and median ( 5th-95th percentile ) PaO(2)/FIO(2 ) ratios were greater with CPAP ( 203 [ 45 - 431 ] mm Hg vs 151 [ 73 - 482 ] mm Hg ; P = .02 ) . No further difference in respiratory indices was observed between the groups . Treatment with CPAP failed to reduce the endotracheal intubation rate ( 21 [ 34 % ] vs 24 [ 39 % ] in the st and ard therapy group ; P = .53 ) , hospital mortality ( 19 [ 31 % ] vs 18 [ 30 % ] ; P = .89 ) , or median ( 5th-95th percentile ) intensive care unit length of stay ( 6.5 [ 1 - 57 ] days vs 6.0 [ 1 - 36 ] days ; P = .43 ) . A higher number of adverse events occurred with CPAP treatment ( 18 vs 6 ; P = .01 ) . CONCLUSION In this study , despite early physiologic improvement , CPAP neither reduced the need for intubation nor improved outcomes in patients with acute hypoxemic , nonhypercapnic respiratory insufficiency primarily due to acute lung injury . JAMA . 2000;284:2352 - 2360 Objective : To assess the role of non-invasive positive pressure ventilation ( NIPPV ) for management of Indian patients with acute exacerbation of chronic obstructive pulmonary disease ( AE COPD ) . Material s and Methods : Forty patients ( mean age 57.6 ± 10.8 years ; M : F 31:9 ) with AE COPD with pH < 7.35 , admitted to the intensive care unit were included . Patients were r and omized to receive  NIPPV  ( N , n = 20 ) with conventional therapy or conventional therapy  ( C , n = 20 ) alone at admission .  NIPPV was given through the nasal mask . Incidence of need of endotracheal intubation ( ETI ) was the primary efficacy variable . Hospital mortality , duration of hospital stay and change in clinical and blood gas parameters were the secondary outcome variables . Results : Mean pH at baseline for N and C groups were similar ( 7.23 ± 0.07 ) whereas PaCO2 was 85.4 ± 14.8 and 81.1 ± 11.6 mm of Hg , respectively . At one hour , patients in N group had greater improvement in pH ( P = 0.017 ) as well as PaCO2 ( P = 0.04 ) which corroborated with clinical improvement . Whereas need of ETI was reduced in patients who received NIPPV ( 3/20 vs 12/20 , P = 0.003 ) , in-hospital mortality was similar ( 3/20 and 2/20 , P = NS ) . The mean duration of hospital stay was significantly shorter in N group ( 9.4 ± 4.3 days ) as compared to C group ( 17.8 ± 2.6 days ) ; P = 0.001 . Conclusions : In patients with AE COPD  , NIPPV leads to rapid improvement in blood gas parameters and reduces the need for BACKGROUND Whether noninvasive ventilation should be administered in patients with acute hypoxemic respiratory failure is debated . Therapy with high-flow oxygen through a nasal cannula may offer an alternative in patients with hypoxemia . METHODS We performed a multicenter , open-label trial in which we r and omly assigned patients without hypercapnia who had acute hypoxemic respiratory failure and a ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen of 300 mm Hg or less to high-flow oxygen therapy , st and ard oxygen therapy delivered through a face mask , or noninvasive positive-pressure ventilation . The primary outcome was the proportion of patients intubated at day 28 ; secondary outcomes included all-cause mortality in the intensive care unit and at 90 days and the number of ventilator-free days at day 28 . RESULTS A total of 310 patients were included in the analyses .  The intubation rate ( primary outcome ) was 38 % ( 40 of 106 patients ) in the high-flow-oxygen group , 47 % ( 44 of 94 ) in the st and ard group , and 50 % ( 55 of 110 ) in the noninvasive-ventilation group ( P=0.18 for all comparisons ) . The number of ventilator-free days at day 28 was significantly higher in the high-flow-oxygen group ( 24±8 days , vs. 22±10 in the st and ard-oxygen group and 19±12 in the noninvasive-ventilation group ; P=0.02 for all comparisons ) . The hazard ratio for death at 90 days was 2.01 ( 95 % confidence interval [ CI ] , 1.01 to 3.99 ) with st and ard oxygen versus high-flow oxygen ( P=0.046 ) and 2.50 ( 95 % CI , 1.31 to 4.78 ) with nonin 
    Output:
    