Comparative study of noninvasive positive pressure ventilation and high-flow nasal cannula oxygen therapy in the treatment of patients with COPD and community-acquired pneumonia

Abstract

This study aims to provide a reference for clinical treatment selection by comparing noninvasive ventilation (NIV) and high-flow nasal cannula (HFNC) oxygen therapy in patients with chronic obstructive pulmonary disease (COPD) complicated by community-acquired pneumonia (CAP). From January 2022 to December 2023, 63 patients with COPD and CAP treated at our hospital were enrolled. Patients were allocated to either the NIV group (33 patients) or the HFNC group (30 patients), in addition to receiving conventional treatments. The groups were compared across various parameters including respiratory rate (RR), peripheral oxygen saturation (SpO₂), arterial oxygen partial pressure (PaO₂), oxygenation index (PaO₂/fraction of inspiration O₂ [FiO₂]), rates of complications, tracheal intubation, mortality, total hospital stay, and hospital costs at 1, 3, and 7 days post-treatment. After 1, 3, and 7 days of treatment, both groups exhibited significant improvements in RR, SpO₂, PaO₂, and PaO₂/FiO₂ from baseline (P < .05). The improvements increased over time. However, no significant differences were observed between the NIV and HFNC groups in RR, SpO₂, PaO₂, and PaO₂/FiO₂ at the measured time points (P > .05); the HFNC group experienced lower rates of complications such as facial injuries, dry nose and mouth, and bloating (P < .05). No significant differences were found in tracheal intubation rates, mortality rates, total hospital stay, and total hospital costs between the groups (P > .05). Both NIV and HFNC effectively improve respiratory and circulatory parameters in patients with COPD and CAP, with similar efficacy rates. While there were no significant differences in tracheal intubation rates, mortality rates, total hospital duration, and costs, HFNC was associated with fewer complications and greater patient comfort, rendering it a more favorable clinical option.

1. Introduction

Chronic obstructive pulmonary disease (COPD), a prevalent respiratory condition, is characterized by significant clinical heterogeneity, primarily manifesting as progressive airflow limitation and recurrent respiratory symptoms such as dyspnea, coughing, expectoration, and reduced activity levels.^[1,2] Patients with COPD frequently present with comorbidities, including community-acquired pneumonia (CAP), a common infectious lung disease.^[3] Factors such as prolonged use of inhaled corticosteroids, advanced age, recurrent episodes, malnutrition, and diminished resistance increase the susceptibility of patients with COPD to CAP.^[4,5] This overlap often exacerbates respiratory symptoms and amplifies both economic and health burdens.^[6] Effective pharmacological intervention and relief of dyspnea and hypoxemia are crucial for reducing exacerbation risks and severe outcomes, highlighting the importance of respiratory support.^[4,7] The primary noninvasive respiratory support options currently include noninvasive ventilation (NIV) and high-flow nasal cannula (HFNC).^[7] Further research is required to ascertain the more beneficial respiratory support method for patients with COPD and CAP. This study employs comparative methods to evaluate the efficacy and safety of NIV and HFNC, aiming to guide clinical decision-making.

2. Materials and methods

2.1. General information

From January 2022 to December 2023, 63 patients with COPD complicated by CAP were recruited from the Department of Respiratory Medicine at the Third People’s Hospital of Nantong City. Inclusion criteria included the following^[7,8]: diagnosis of COPD and CAP according to established criteria, no improvement in respiratory distress or hypoxemia after standard oxygenation via nasal cannula or mask, and ability to remain conscious and cooperate with NIV or HFNC therapy. Exclusion criteria comprised the following^[7,8]: need for invasive mechanical ventilation, (2) withdrawal mid-study, and (3) contraindications to NIV or high-flow oxygen therapy.^[7] Patients were allocated into 2 groups through a random table method based on their method of respiratory support: an NIV group (33 patients) and an HFNC group (30 patients). They have passed the significance test for differences and can be compared. Comparative analysis of demographic and clinical data, including gender, age, weight, and comorbidities (all P > .05; Table 1). Comparative analysis of body temperature, pulse, carbon dioxide partial pressure in blood gases, and antibiotic types revealed no significant differences (all P > .05; Table 2). The study was approved by the ethics committee of Third People’s Hospital of Nantong, China (clinical trial no. EK2023162). The participants all provided written informed consent.

Table 1.

General data of patients with COPD with pneumonia in both groups.

Group	Gender		Age (yr)	Weight (kg)	Comorbidities (cases)
	Male	Female			Hypertension	Diabetes	Heart disease
NIV group (n = 33)	26	7	79.9 ± 6.5	62.1 ± 12.0	14	8	9
HFNC group (n = 30)	24	6	80.6 ± 7.9	64.5 ± 12.2	14	7	7
t/χ2	0.014		−0.341	−0.702	0.115	0.007	0.129
P	.905		.735	.486	.735	.933	.720

COPD = chronic obstructive pulmonary disease, HFNC = high-flow nasal cannula, NIV = noninvasive ventilation.

Table 2.

Basic admission information and types of antibiotics used in both groups.

Group	Body temperature (°C)	Pulse (beats/min)	PaCO2 (mm Hg)	Antibiotics
				β-lactam	Quinolones
NIV group (n = 33)	37.1 ± 0.9	96.7 ± 18.9	50.5 ± 12.8	30	3
HFNC group (n = 30)	37.1 ± 0.8	91.4 ± 15.7	47.3 ± 10.9	25	5
t/χ2	−0.265	1.108	0.966	0.814
P	.792	.273	.339	.367

HFNC = high-flow nasal cannula, NIV = noninvasive ventilation.

2.2. Treatment protocol

The treatment protocols were established in accordance with guidelines for COPD and CAP.^[7,8]

1. General treatment: This included monitoring vital signs, ensuring adequate energy and nutritional intake, maintaining electrolyte balance and internal environment stability, and conducting necessary examinations based on the patient’s condition.

2. Pharmacological treatment: Tailored to the patient’s needs, treatments included anti-infection agents, bronchodilators, corticosteroids, and cough and expectorant medications; additional treatments were provided for other underlying diseases as needed.

3. Respiratory support: For patients unresponsive to oxygenation via nasal cannula or mask and experiencing respiratory distress and/or hypoxemia, advanced respiratory support was initiated, choosing between NIV or HFNC. The NIV group was equipped with the ResMed bilevel noninvasive ventilator ST25-H with initial settings of S/T mode, oxygen concentration of 30% to 60%, respiratory rate (RR) of 14 to 18/minute, inspiratory pressure of 12- to 20-cm H₂O, and expiratory pressure of 4- to 8-cm H₂O. The HFNC group utilized the New Zealand ARIVO2 high-flow humidified oxygen therapy device, with settings of oxygen flow of 30 to 60 L/min, oxygen concentration of 30% to 80%, humidification temperature of 34 °C to 37 °C, and humidity at 100%. Parameters were adjusted based on peripheral oxygen saturation (SpO₂) and individual patient conditions to maintain pulse oximetry (SpO₂) ≥90%.

2.3. Data collection process

Possible confounding variables have been removed through logistic regression analysis before starting this study. After admission, patients were grouped according to inclusion and exclusion criteria, and targeted therapy was strictly performed according to standard guidelines. At the same time, request the attending physician to closely monitor changes in the patient’s condition, record any adverse reactions that occur during the course of the illness, and invite ≥2 associate chief physicians to confirm. Request the attending physician to adjust the treatment in a timely manner according to the patient’s condition. On the first, third, and seventh days of treatment, recheck blood gas analysis and other indicators to ensure the accuracy of the test results and avoid external interference.

2.4. Observation indicators

Data were systematically collected and analyzed from both groups at 1, 3, and 7 days post-treatment. Parameters included pulse, RR, SpO₂, arterial oxygen partial pressure (PaO₂), and PaO₂/fraction of inspiration O₂ (FiO₂). Complications such as facial injury, dry nose and mouth, bloating, tracheal intubation rates, mortality rates, total hospitalization duration, and costs were also assessed. This analysis aimed to delineate the characteristics and advantages of each respiratory support method.

2.5. Data analysis

All statistical analyses were performed using IBM SPSS Statistics for Windows, version 25.0 (IBM Corp, Armonk, NY). Measurement data were presented as mean ± standard deviation (X ± s) and analyzed using an unpaired Student t test, while counting data were expressed as percentages (%) and assessed using the χ² test. A 2-sided P < .05 was considered statistically significant. The study conforms to STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) guidelines.

3. Results

3.1. Respiratory circulation indicators

Both groups demonstrated a significant reduction in RR from baseline at 1, 3, and 7 days of treatment (all P < .05), with concurrent increases in SpO₂, PaO₂, and PaO₂/FiO₂ with concurrent increases in (all ^*P < .01). Analysis within groups from 1 to 3 days, and from 3 to 7 days, revealed further reductions in RR and increases in SpO₂, PaO₂, and PaO₂/FiO₂ (all †P < 0.01); after 7 days of treatment compared with 3 days within the same groups, both groups showed further decreases in RR and increases in SpO₂, PaO₂, and PaO₂/FiO₂ (all ‡P < .01; all §P < .05). However, no statistically significant differences were observed in RR, SpO₂, PaO₂, and PaO₂/FiO₂ between the NIV and HFNC groups at the various time points (all P > .05; Table 3).

Table 3.

Comparison of respiratory and circulatory parameters before and after treatment.

Time	RR (breaths/min)		t	P	SpO2 (%)		t	P
	NIV group (n = 33)	HFNC group (n = 30)			NIV group (n = 33)	HFNC group (n = 30)
Pretreatment	28.2 ± 3.1	29.5 ± 3.0	−1.640	.107	84.1 ± 7.1	83.6 ± 6.5	0.264	.793
Day 1	25.2 ± 4.5*	26.5 ± 3.8*	−1.123	.266	88.9 ± 4.9*	87.6 ± 5.1*	0.889	.378
Day 3	21.7 ± 2.4*,†	22.3 ± 2.3*,†	−0.857	.395	91.9 ± 3.5*,†	90.9 ± 4.2*,†	0.954	.345
Day 7	20.2 ± 1.2*,†,‡	20.4 ± 1.1*,†,‡	−0.652	.518	94.1 ± 3.8*,†,‡	94.7 ± 1.9*,†,‡	−0.682	.498

Time	PaO2 (mm Hg)		t	P	PaO2/FiO2 (mm Hg)		t	P
	NIV group (n = 33)	HFNC group (n = 30)			NIV group (n = 33)	HFNC group (n = 30)
Pretreatment	54.5 ± 9.4	53.4 ± 7.3	0.463	.645	235.9 ± 38.4	234.6 ± 32.6	0.139	.890
Day 1	61.2 ± 8.1*	58.2 ± 7.8*	1.337	.187	269.4 ± 36.0*	262.6 ± 27.1*	0.751	.456
Day 3	67.6 ± 12.5*,†	68.4 ± 10.7*,†	−0.232	.817	292.1 ± 35.7*,†	296.7 ± 37.4*,†	−0.444	.659
Day 7	76.4 ± 17.3*,†,§	75.1 ± 8.8*,†,‡	0.302	.764	331.4 ± 46.1*,†,‡	336.7 ± 29.4*,†,‡	−0.456	.651

FiO₂ = fraction of inspiration O₂, HFNC = high-flow nasal cannula, NIV = noninvasive ventilation, PaO₂ = arterial oxygen partial pressure, RR = respiratory rate, SpO₂ = peripheral oxygen saturation.

^*Compared with pretreatment values within the same group: P < .01.

^†Compared with day 1 values: P < .01.

^‡Compared with day 3 values: P < .01.

^§Compared with day 3 values: P < .05.

3.2. Prognostic outcome indicators

The incidence of complications such as facial pressure injuries, dry nose and mouth, and bloating was higher in the NIV group compared with the HFNC group (χ² = 3.955; P = .047 < .05). However, there were no statistically significant differences in tracheal intubation rates between the NIV and HFNC groups (χ² = 0.543; P = .461 > .05). There were no statistically significant differences in mortality rates between the NIV and HFNC groups (χ² = 0.258; P = .612 > .05; Table 4).

Table 4.

Comparison of complications, tracheal intubation rates, and mortality rates between the groups (cases, %).

	NIV group (n = 33)	HFNC group (n = 30)	χ2	P
Complications	10 (30.30)	3 (10.00)	3.955	.047
Facial pressure injuries	4 (12.12)	0 (0.00)
Dry nose and mouth	3 (9.09)	2 (6.67)
Bloating	3 (9.09)	1 (3.33)
Tracheal intubation	4 (12.12)	2 (6.67)	0.543	.461
Death	2 (6.06)	1 (3.33)	0.258	.612

HFNC = high-flow nasal cannula, NIV = noninvasive ventilation.

3.3. Economic indicators

There were no statistically significant differences between the NIV and HFNC groups in terms of total hospitalization time (t = 0.357; P = .722 > .05). There were no statistically significant differences between the NIV and HFNC groups in terms of total hospitalization costs (t = −0.163; P = .871 > .05; Table 5).

Table 5.

Comparison of treatment costs and hospitalization duration between the groups.

Group	Hospitalization duration (d)	Hospitalization costs (10,000 yuan)
NIV group (n = 33)	13.6 ± 8.1	2.29 ± 1.53
HFNC group (n = 30)	12.8 ± 7.7	2.36 ± 1.29
t	0.357	−0.163
P	.722	.871

HFNC = high-flow nasal cannula, NIV = noninvasive ventilation.

4. Discussion

COPD is characterized by an airflow limitation, which is not fully reversible. At present, COPD is the fourth leading cause of incidence rate and mortality worldwide and is expected to become one of the major causes of disability.^[9,10] CAP is a frequent comorbidity in patients with COPD, which can further impair lung function and intensify existing respiratory symptoms.^[3] Research indicates that ≈8% to 36% of patients with COPD hospitalized for acute respiratory worsening are diagnosed with CAP based on imaging.^[6,11–13] For patients requiring respiratory support, noninvasive positive pressure ventilation is a classic treatment option for patients with COPD with acute respiratory failure.^[14] Soleimanpour et al^[15] found that patients requiring NIV accounted for 43.9% of all study patients. The sensitivities of rapid shallow breathing index and Acute Physiology and Chronic Health Evaluation II scores are 94.8% and 72%, respectively, indicating high diagnostic sensitivity, and can be used as predictive factors for NIV demand.^[15]

HFNC oxygen therapy, another form of respiratory support, administers high-velocity mixed gas at appropriate temperature and humidity levels through a specialized nasal cannula, enhancing oxygenation in patients.^[16–18] In addition, evidence supports HFNC as a viable option for stable hypercapnic and exacerbation-prone patients with COPD.^[19] However, guidance for choosing respiratory support strategies for patients with COPD who also experience CAP is scant. Our study, controlling for various potential confounders and comparing NIV and HFNC in treating patients with COPD with pneumonia, demonstrated that both groups experienced significant improvements in RR, SpO₂, PaO₂, and PaO₂/FiO₂ ratios after 1, 3, and 7 days of treatment, with benefits increasing over time; the longer the treatment, the more pronounced the improvements. At different assessment points, no significant differences were observed between the 2 groups; both treatment modalities yielded similar results in terms of tracheal intubation rates, mortality rates, hospitalization duration, and costs, indicating that both NIV and HFNC are effective in enhancing patients’ respiratory and circulatory parameters without imposing additional burdens.

Although both NIV and HFNC demonstrate effective therapeutic results in treating COPD with CAP, complications associated with NIV are more prevalent. Clinically, airway management interventions are significantly more frequent in the NIV group compared with the HFNC group, attributable to HFNC’s superior design for nasal comfort and congestion alleviation. Patients using NIV frequently remove their masks due to discomfort, intolerance, eating, expectoration, communication challenges, or mask displacement, consequently increasing the nursing workload.^[20] In contrast, HFNC users face fewer restrictions during eating, expectorating, and communicating, resulting in lower incidences of complications such as skin damage and dry nasal and oral passages, corroborating studies by Tan et al.^[21] In addition, NIV may exacerbate lung injury from excessively high pressures and tidal volumes.^[22] HFNC’s design avoids inducing claustrophobia and promotes compliance; in addition, its heating and humidifying capabilities ensure that delivered gases maintain optimal humidity and temperature, enhancing secretion clearance and reducing dryness in nasal and oral mucous membranes.^[23] Given these attributes, patients can comfortably tolerate HFNC’s high gas flows of 50 to 60 L/min, making it generally more tolerable than NIV.^[21] However, the number of patients in this study is relatively small. In the future, we will collaborate with other relevant hospitals to increase the number of patients and make the conclusions of this study more universal. This study did not stratify patients again based on key clinical indicators such as arterial pH and PaCO₂ levels, which may make the conclusions of this study rough. As most of the patients in this study have already been discharged, it is currently impossible to make up for this deficiency. We will take this into consideration in future studies.

In summary, while both NIV and HFNC yield favorable therapeutic outcomes for patients with COPD and CAP, HFNC offers enhanced comfort and compliance, and fewer complications and is suitable for patients intolerant to NIV. This article recommends further investigation to ascertain any differential treatment outcomes between the 2 modalities in patients with COPD with CAP who exhibit significant carbon dioxide retention.

Author contributions

Data curation: Wangfei Ji, Xiaobai Zhang.

Funding acquisition: Wangfei Ji.

Writing – original draft: Wangfei Ji, Honghua Ji, Chenhui Wang, Lina Xu.

Writing – review & editing: Wangfei Ji, Xiaobai Zhang, Chenhui Wang, Lina Xu.

Formal analysis: Xiaobai Zhang, Lina Xu.

Investigation: Xiaobai Zhang, Lina Xu.

Resources: Honghua Ji, Chenhui Wang.

Software: Honghua Ji.

Methodology: Chenhui Wang.