Objective To compare and analyze the clinical effectiveness of early versus delayed noninvasive ventilator treatment of acute left heart failure combined with type Ⅱ respiratory failure.Methods One hundred and twenty patients with acute left heart failure combined with type Ⅱ respiratory failure

admitted to a hospital in Henan Province from June 2018 to August 2020

were selected as subjects and assigned to an early group and a delayed group via the random number table method

with 60 cases in each group.Patients in the early group received early noninvasive ventilators on the basis of basic treatment.Patients in the delayed group received noninvasive ventilators after 2 h of basic treatment when the patients’ symptoms were not relieved

with the same parameters as in the early group.The heart rate（HR）

respiratory rate（RR）

partial pressure of oxygen（Pa O2） and mean arterial pressure（MAP） levels before and at 3 h of treatment were compared between the two groups.The time to symptom improvement and hospitalization time were compared between the two groups.Before treatment and at 3 h of treatment

the forced expiratory volume in1s（FEV1）

forced vital capacity（FVC） and FEV1/FVC were compared between the two groups.Results There was no statistically significant difference in HR

RR

MAP

and Pa O2 levels before treatment between the 2 groups（P>0.05）.The levels of HR

RR and MAP in both groups after treatment were lower than those before treatment

and the early group showed lower levels than the delayed group

and the differences were statistically significant（P<0.05）;while the Pa O2 was higher than that before treatment

and the early group had higher Pa O2 than the delayed group

and the differences were statistically significant（P<0.05）.The duration of hospitalization and the time to symptom improvement were shorter in the early group than those in the delayed group

and the differences were statistically significant（P<0.05）.FEV1

FVC

and FEV1/FVC levels before treatment in the 2 groups were compared

and the differences were not statistically significant（P>0.05）.FEV1

FVC

and FEV1/FVC levels after treatment were higher in the 2 groups than those before treatment

and the early group was higher than the delayed group

and the differences were statistically significant（P<0.05）.Conclusion Early non-invasive ventilator treatment for acute left heart failure combined with type Ⅱ respiratory failure can effectively improve patients’ clinical symptoms

shorten hospitalization time and time to symptom improvement

and promote patients’ recovery

which is worthy of clinical promotion and application.