|Year : 2022 | Volume
| Issue : 1 | Page : 1-6
Change in quality of life with nasal CPAP in patients with OSA
Venkateswara Rao Teela, C. Raghavendra, P. Kalyan Kumar
Department of Pulmonary Medicine, Maharajah’s Institute of Medical Sciences, Nellimarla, Vizianagaram, Andhra Pradesh, India
|Date of Submission||10-Sep-2020|
|Date of Acceptance||10-Sep-2020|
|Date of Web Publication||19-Apr-2022|
Dr. Venkateswara Rao Teela
Venkateswara Rao Teela, Department of Pulmonary Medicine, MIMS, Vizianagaram, Nellimarla 535217, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
Background: Obstructive sleep apnea (OSA) is a major global problem, associated with increased morbidity mortality and decreased quality of life. There are many possible treatment options, but noninvasive ventilation (NIV) nasal continuous positive airway pressure (CPAP) is most commonly used and most effective modality. In this study, we evaluated and assessed 30 cases of patients with OSA. Patients and methods: A prospective study was performed by using Short Form 36 (SF-36) questionnaire; OSA was assessed pre- and post-NIV therapies for 1 month. Results and conclusion: This study demonstrated a marked impairment of the quality of life in patients with even mild OSA. One month of CPAP treatment improved the quality of life in the all domains of SF-36 health questionnaire. We concluded that health-related quality of life of patients with OSA improved remarkably with CPAP therapy.
Keywords: NIV nasal CPAP, OSA, SF-36 questionnaire, quality of life
|How to cite this article:|
Teela VR, Raghavendra C, Kumar PK. Change in quality of life with nasal CPAP in patients with OSA. J Assoc Chest Physicians 2022;10:1-6
| Introduction|| |
Obstructive sleep apnea (OSA) is characterized by recurrent obstruction of the upper airway. This results in episodic asphyxia, oxygen desaturation, and disruption of the normal sleep pattern. The majority of patients with OSA have symptoms related to poor sleep and consequently excessive daytime sleepiness and tiredness, lack of concentration, memory impairment, and at times psychologic disturbances.,, OSA is also associated with cardiovascular and cerebrovascular morbidity and mortality.,, Because of these symptoms and functional impairments, patients often report to having a poor quality of social, emotional, and physical domains.,,
Treatments for OSA include positional training, weight loss, and avoidance of alcohol and sedative drugs. In addition, the others are mandibular advancement devices, continuous positive airway pressure (CPAP), and upper airway surgery. The most commonly used and most effective treatment modality has been nasal CPAP,,, CPAP has been shown to decrease the frequency of apneic events and oxygen desaturation and it reduces the severity of sleep disturbances and daytime sleepiness.,
In this study, we evaluated the overall quality of life (QOL), rather than symptoms directly associated with the disease using Short Form 36 (SF-36) questionnaire. The objective of the present study is to assess the QOL after using noninvasive ventilation (NIV) for a period of 1 month in patients with OSA.
| Materials and methods|| |
This study spanned over 2 years from July 2019 to April 2021. Thirty-eight patients were diagnosed as OSA [respiratory disturbance index (RDI) ≥ 5] and CPAP therapy was given. Before starting CPAP therapy, each patient completed the Medical Outcomes Study SF-36 questionnaire and their baseline anthropometric measurements were recorded.
Patients who were willing to undergo CPAP therapy, who bought CPAP machine for their own treatment, and who were adherent to CPAP therapy.
Adherence of CPAP is defined as CPAP >4 hours/night following cutoff state in the majority of studies and is based on frequency over >70% of total treatment days.,.
Patients who were not adherent to CPAP therapy and who were having other diseases which could potentially bias perception of QOL, such as chronic obstructive lung diseases, bronchial asthma, interstitial lung disease, heart failure, renal failure, hypothyroidism, depression, chronic psychiatric disorders, and psychotropic drug abuse were excluded. The patients who had other sleep disorders or received treatment other than CPAP for their OSA were also excluded in this study.
Quality of life assessment
The SF-36 questionnaire measures how the patient perceives his/her own functional status, well-being, and overall health. SF-36 health survey questionnaire is one of the products of RAND Corporation’s Health insurance experiment and subsequent medical outcome study. It has become one of the most frequently used and validated measures of subjective health status. It measures eight multi-item dimensions. For each dimension, item scores are coded, summed, and transformed on to a scale from 0 to 100 (worst–best possible health).
Two summary scores of physical (physical component summary − PCS) and emotional well-being (mental component summary − MCS) are calculated, which replicate the results from eight dimensions of SF-36 with considerable economy and also reduce the role of chance in gaining statistical significance due to multiple comparisons. Furthermore, the PCS and MCS are “standardized” such that a mean score of 50 and a standard deviation of 10 reflect the mean score of the population, in this instance gained from the Oxford Health Lifestyle Survey.
Polysomnography was performed by using sleep machine (Compumedics, Ciesta PSG, Compumedics USA Inc, USA corporate HQ) between 9:00 pm and 7:00 am. The sleep state was recorded with two channels of electroencephalogram (C3/A2 or C4/A1, O2/A1 or O1/A2), two channels of electro-oculogram, and one channel of submental electromyogram. Breathing was assessed by monitoring chest wall and abdominal movements using strain gauge pneumatograph. Nasal and oral flows were monitored using thermistors. Arterial oxygen saturation was measured using a pulse oximeter. Leg movements were monitored with two-channel electromyogram, and an electrocardiogram was recorded continuously. All variables were recorded simultaneously and continuously on a 16-channel polygraph. Sleep recordings were scored in 30-second epochs and staged according to standard criteria. Calculated variables included the number of arousals, the RDI (apnea/hypopnea index), and the number and degree of arterial oxygen desaturations.
Apneic variations were classified using the following definitions: Apnea was present when there is complete cessation of airflow for 10 seconds, obstructive apnea was present when respiratory efforts were present, central apnea was present when respiratory efforts were absent, and mixed apneas occurred when there was a central component followed by an obstructive component. Hypopnea was scored when there was a ≥50% decrease in the airflow signal with 3% decrease in arterial oxygen saturation. The optimal CPAP level during the sleep study was the lowest pressure associated with the least number of respiratory events and arousals and the highest sleep efficiency.
Initiating nasal CPAP therapy
The night of the sleep study, nasal CPAP was started in all patients who were diagnosed with OSA. Skilled technical staff members choose the most suitable nasal mask and headgear for the subjects, ensuring that they were comfortable with the system. The first spell of treatment was given in the laboratory, using an auto-adjust nasal CPAP system which adjusts CPAP according to the presence of snoring, apneas, and hypopneas. During the night of CPAP titration, subjects were monitored with a multichannel system, monitoring a dip rate of 3% in oxygen saturation, snoring and arousal confirmed by movements. and brief increases in heart rate.
The following morning, the level of CPAP for home use was chosen as that which controlled all snoring and sleep fragmentation related to upper-airway incompetence (in all subjects, this was the 90th percentile of overnight CPAP pressure or higher).
For the nonsnoring subjects, in whom the auto-adjust nasal CPAP did not rise above 3 cm H2O, the minimum CPAP used was set to 5 cm H2O to ensure adequate flow of air through the nasal mask and to prevent hypoxemia associated with rebreathing. Standard operating procedure was observed. Follow-up was performed after 1 month.
Data analysis was performed using SPSS Software version 15 and Sigma plot Version 11 developed by SYSTAT software Inc. P-value less than 0.05 is taken as significant level.
| Observations and results|| |
This prospective study conducted in 38 patients with OSA but 8 patients did not come for follow-up hence, we finally included 30 patients in this study, out of which 22 (73.33%) males and 8 (26.67%) females, and the mean age of the patients was 58.33 ± 14.08 years (range, 20–87 years), the average body mass index was 36.3 ± 2.0 kg/height m2 (range, 25.9–54.1). Seven patients had no comorbidities, and the others had histories of coronary heart disease, hypertension, diabetes mellitus, and arthritis. In those, 23 patients (76.6%) had hypertension, 16 patients (53.3%) had diabetes, 8 patients had coronary heart disease (26.6%), 12 patients had both hypertension and diabetes (40%), 5 patients (16.6%) had histories of all of three, that is, coronary heart disease, hypertension, and diabetes mellitus, and 2 patients (6.6%) had arthritis. All of the patients were medically stable at the time of their initial evaluation and on follow-up. On average, the patients had severe OSA with RDI of 24.52 ± 20.937 (range, 5–87.3).
The patients had significantly decreased health status in all domains of SF-36 role functioning, physical functioning, energy and fatigue, emotional health, pain, and general health perceptions. To determine the effect of the severity of sleep apnea on the QOL, the indicators of disease severity, the RDI, and age, body mass index (BMI), and QOL scores on the SF-36 at prior to treatment were correlated. Some patients with mild OSA reported significant impairment in their QOL, although others with more severe OSA perceived a lesser amount of functional decline. However, significant correlations were found between QOL scores on the SF-36 prior to CPAP administration and the subsequent change in scores after treatment in role limitation due to physical health (correlation coefficient −0.570) and role limitation emotional health (correlation coefficient −0.474), energy and fatigue (correlation coefficient −0.508), and emotional well-being (correlation coefficient −0.707). In other words, patients with lower scores and more impairments on the SF-36 before treatment demonstrated larger improvements in SF-36 in these domains after treatment in above domains.
All patients underwent and responded to CPAP treatment, with a reported use time of 6.0 ± 1.6 hours/night. After 1 month of CPAP treatment, the patients reported a significant improvement in physical functioning (P < 0.001), role limitation due to physical health (P = 0.003), role limitation emotional health (P = 0.007), energy and fatigue (P < 0.001), social functioning (P < 0.001), emotional well-being (P < 0.001), general health perceptions (P < 0.001), and except in bodily pain (P = 0.071) when compared with pretreatment values for each individual. The observed results in our study are given in [Table 1] and [Table 2].
| Discussion|| |
There is a paucity of Indian studies regarding the outcome of CPAP therapy in patients with OSA. Comparison was made with western studies who used SF-36 questionnaire for measurement of QOL in their study [Table 3].
The present study showed SF-36 score in physical function domain before and after treatment were 51.50 ± 18.48 and 57 ± 19.50, respectively. This is attributed to the mean age of the patients 58.33 ± 14.08 years (range, 20–87 years) and average body mass index (range, 25.9–54.1﴿ which are higher compared to other mentioned studies of F. Pichel, C. Zamaron, Magan. Bennett, Barbour, Langford, et al. studied age of 49 years (range, 29–62 years) with a mean BMI of 32. John R. Stradling, Mullin, Jenkinson et al. studied an age group of 51.8 years average. Although factors other than sleep apnea, such as obesity and comorbidities, adversely affect the QOL, the rapid improvement in functions after CPAP therapy suggests that sleep apnea is the main cause of functional impairment.
SF-36 score was 50.38 ± 17.07 and 63.46 ± 13.17 for pre- and posttreatments, respectively. This is comparable to those of all above-mentioned studies except F. Pichel, C. Zamaron, Magan, et al. Most of the above-mentioned studies are conducted in the United Kingdom.
SF-36 score was 39.83 ± 12.49 and 55.00 ± 12.50 for pre- and posttreatments, respectively. They are similar to those of Bennett, Barbour, Langford, et al.
SF-36 score was 47.50 ± 15.87 and 61.33 ± 16.57 for pre- and posttreatments, respectively, which is comparable to all mentioned studies. The health-related QOL (HRQOL) has cross-cultural and regional differences even in same clinical condition. Thus, the conclusions drawn from researches performed outside India cannot be used to gauge QOL impairment in Indian patients with OSA. Gall et al. using SF-36 observed that patients with OSA have significant impaired social functioning.
The present SF-36 score was found to be 62.50 ± 18.18 and 64.57 ± 18.80 for pre- and posttreatments, respectively. There is no significant improvement in bodily pain in all above-mentioned studies including the present study. The results were better than the studies of Akashiba et al.
General health perception:
SF-36 score was found to be 5.90 ± 19.2 and 54.57 ± 18.09 for pre- and posttreatments, respectively. The present study is comparable to all studies except to that of C. Jenkinson et al. and F. Pichel, C. Zamaron, Magan, et al. The sleepiness correlated with energy and fatigue and general health perception domains of SF-36 in a group of patients with mild to moderate OSA. Average of age group and BMI, which are higher compare to other studies and histories of other comorbidities such as coronary heart disease, hypertension, diabetes mellitus, and arthritis also could have affected the general health of the study population.
SF-36 score in role limitations due to physical problem domain was 54.44 ± 30.06 and 68.61 ± 25.11 for pre- and posttreatments, respectively, comparable to that of C. Jenkinson et al. In F. Pichel, C. Zamaron, Magan, et al. study, they observed that it was 59.42 ± 30.06 and 68.61 ± 25.11, respectively. Our study thus shows a considerable limitation.
The present study is comparable with C. Jenkinson et al. and John R. Stradling, Mullin, Jenkinson, et al., though extent of improvement somewhat higher than present study. Bennett, Barbour, Langford, et al. showed no decrement in pretreatment score. This could be due to study population which included subjects who did not have OSA (e.g., nonsnorers) and who were only receiving CPAP for the purposes of this study. F. Pichel, C. Zamaron, Magan, et al. showed better improvement than the present study. This could be because of longer duration of study (6 months). Their study also recorded improvement after 18 months of treatment and concluded that HRQOL improves with long-term CPAP treatment. Our study demonstrates that the QOL in patients with OSA is severely impaired and can be improved with CPAP therapy. All domains of the QOL were impaired by OSA when compared with the QOL prior to treatment as also shown in above-mentioned studies. Even though degree of improvements was about the same in all short-term studies, QOL impairment prior to treatment was more in this present study. This could be attributed to 23 patients (76.6%) of this study population also having other comorbidities such as coronary heart disease, hypertension, diabetes mellitus, and arthritis and high average BMI (36.3 ± 2.0), high average age (58.33 ± 14.08). OSA impacted on the QOL in various ways. Some patients with rather mild OSA reported the same degree of impairment in SF-36 domains, as did those with more severe cases of the disease. The diminished QOL measures did not correlate with disease severity. Similar to the present study, other investigators have shown no correlation between the severities of sleep apnea. OSA is commonly associated with neuropsychiatric disturbances that could interfere with the capacity of the patient to fully appreciate the quality of his/her state of health. This could explain the lack of correlation between OSA severity and the self-perceived health status. Our data and the data mentioned above differ from the study of Tousignant et al., which demonstrated a correlation between RDI and pretreatment health state indicating that the higher the severity of disease the lower is the health status. The reason for this discrepancy may be because this study was conducted retrospectively and, therefore may have been biased because of errors in recall about the pretreatment health state. Furthermore, there were some inconsistencies in the response to treatment in the aforementioned study. An optimal CPAP level was achieved for all patients during the study. The use of CPAP ranged from 3 to 8 hours/night for the duration of study. After 1 month of CPAP therapy, the patients reported a significant improvement in physical functioning (P < 0.001), role limitation due to physical health (P = 0.003), role limitation emotional health (P = 0.007), energy and fatigue (P < 0.001), social functioning (P < 0.001), emotional well-being (P < 0.001), and general health perceptions (P < 0.001), except in bodily pain (P = 0.071) when compared with pretreatment values for each individual. The improvement in these domains was independent of the RDI or other indicators of OSA severity. The degree of impairment in QOL domains but not the severity of disease determined the degree of improvement with CPAP. In a study by Bearpark et al., of 204 CPAP users, there was a significant improvement in daytime sleepiness and a reduction in road traffic incident rate.
The use of CPAP correlated positively with symptoms prior to treatment and not with the severity of OSA. The reported average (6SD) use of nasal CPAP in this study was 5.8 ± 2.0 hours/night, which is comparable to our average of 6.0 ± 1.6 hours/night. One explanation is that patients with more severe OSA but with less perceived impairment in life domains did not use CPAP regularly and did not report a significant change in their functions. Another reason for the lack of a relationship between OSA severity and the perceived improvement in QOL could be that patients with severe OSA having cognitive deficit could underestimate the impairment in their own accord.
Limitations of the study
Our study is having some limitations, which might have affected the results. They are as follows:
- The study may not be the true representative of the population as cases are small in number.
- The cases may not be the true representative of the population as females were under represented when compared with population prevalence.
- Though SF-36 is one of the most frequently used and validated measures of subjective health status, the HRQOL has cross-cultural and regional differences even in same clinical condition. Thus, the conclusions drawn from researches performed outside India cannot be used to gauge QOL impairment in Indian patients with OSA.
| Conclusion|| |
In conclusion, this study demonstrated a marked impairment of the QOL in patients with even mild OSA, and that 1 month of CPAP treatment improves the QOL all domains of SF-36 health questionnaire (physical functioning, role limitation due to physical health, role limitation emotional health, energy and fatigue, social functioning, emotional well-being, and general health perceptions) except bodily pain.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]